Merge remote-tracking branch 'origin/master' into copilot/add-performance-benchmarking

# Conflicts:
#	tests/SharpCompress.Performance/packages.lock.json

.editorconfig

@@ -307,6 +307,7 @@ dotnet_diagnostic.CS8602.severity = error
 dotnet_diagnostic.CS8604.severity = error
 dotnet_diagnostic.CS8618.severity = error
 dotnet_diagnostic.CS0618.severity = suggestion
+dotnet_diagnostic.CS1998.severity = error
 dotnet_diagnostic.CS4014.severity = error
 dotnet_diagnostic.CS8600.severity = error
 dotnet_diagnostic.CS8603.severity = error

.gitignore

@@ -4,8 +4,8 @@ _ReSharper.SharpCompress/
 bin/
 *.suo
 *.user
-tests/TestArchives/Scratch/
-tests/TestArchives/Scratch2/
+TestArchives/Scratch/
+TestArchives/Scratch2/
 TestResults/
 *.nupkg
 packages/*/
@@ -20,3 +20,7 @@ artifacts/
 
 .DS_Store
 *.snupkg
+
+# BenchmarkDotNet artifacts
+BenchmarkDotNet.Artifacts/
+**/BenchmarkDotNet.Artifacts/

AGENTS.md

@@ -178,59 +178,5 @@ SharpCompress supports multiple archive and compression formats:
 2. **Solid archives (Rar, 7Zip)** - Use `ExtractAllEntries()` for best performance, not individual entry extraction
 3. **Stream disposal** - Always set `LeaveStreamOpen` explicitly when needed (default is to close)
 4. **Tar + non-seekable stream** - Must provide file size or it will throw
+5. **Multi-framework differences** - Some features differ between .NET Framework and modern .NET (e.g., Mono.Posix)
 6. **Format detection** - Use `ReaderFactory.Open()` for auto-detection, test with actual archive files
-
-### Async Struct-Copy Bug in LZMA RangeCoder
-
-When implementing async methods on mutable `struct` types (like `BitEncoder` and `BitDecoder` in the LZMA RangeCoder), be aware that the async state machine copies the struct when `await` is encountered. This means mutations to struct fields after the `await` point may not persist back to the original struct stored in arrays or fields.
-
-**The Bug:**
-```csharp
-// BAD: async method on mutable struct
-public async ValueTask<uint> DecodeAsync(Decoder decoder, CancellationToken cancellationToken = default)
-{
-    var newBound = (decoder._range >> K_NUM_BIT_MODEL_TOTAL_BITS) * _prob;
-    if (decoder._code < newBound)
-    {
-        decoder._range = newBound;
-        _prob += (K_BIT_MODEL_TOTAL - _prob) >> K_NUM_MOVE_BITS;  // Mutates _prob
-        await decoder.Normalize2Async(cancellationToken).ConfigureAwait(false);  // Struct gets copied here
-        return 0;  // Original _prob update may be lost
-    }
-    // ...
-}
-```
-
-**The Fix:**
-Refactor async methods on mutable structs to perform all struct mutations synchronously before any `await`, or use a helper method to separate the await from the struct mutation:
-
-```csharp
-// GOOD: struct mutations happen synchronously, await is conditional
-public ValueTask<uint> DecodeAsync(Decoder decoder, CancellationToken cancellationToken = default)
-{
-    var newBound = (decoder._range >> K_NUM_BIT_MODEL_TOTAL_BITS) * _prob;
-    if (decoder._code < newBound)
-    {
-        decoder._range = newBound;
-        _prob += (K_BIT_MODEL_TOTAL - _prob) >> K_NUM_MOVE_BITS;  // All mutations complete
-        return DecodeAsyncHelper(decoder.Normalize2Async(cancellationToken), 0);  // Await in helper
-    }
-    decoder._range -= newBound;
-    decoder._code -= newBound;
-    _prob -= (_prob) >> K_NUM_MOVE_BITS;  // All mutations complete
-    return DecodeAsyncHelper(decoder.Normalize2Async(cancellationToken), 1);  // Await in helper
-}
-
-private static async ValueTask<uint> DecodeAsyncHelper(ValueTask normalizeTask, uint result)
-{
-    await normalizeTask.ConfigureAwait(false);
-    return result;
-}
-```
-
-**Why This Matters:**
-In LZMA, the `BitEncoder` and `BitDecoder` structs maintain adaptive probability models in their `_prob` field. When these structs are stored in arrays (e.g., `_models[m]`), the async state machine copy breaks the adaptive model, causing incorrect bit decoding and eventually `DataErrorException` exceptions.
-
-**Related Files:**
-- `src/SharpCompress/Compressors/LZMA/RangeCoder/RangeCoderBit.Async.cs` - Fixed
-- `src/SharpCompress/Compressors/LZMA/RangeCoder/RangeCoderBitTree.Async.cs` - Uses readonly structs, so this pattern doesn't apply

Directory.Build.props

@@ -12,6 +12,5 @@
     <RunAnalyzersDuringBuild>False</RunAnalyzersDuringBuild>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
-    <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
 </Project>

Directory.Packages.props

@@ -1,18 +1,18 @@
 <Project>
   <ItemGroup>
+    <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageVersion Include="Bullseye" Version="6.1.0" />
     <PackageVersion Include="AwesomeAssertions" Version="9.3.0" />
     <PackageVersion Include="Glob" Version="1.1.9" />
     <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.15" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.0" />
-    <PackageVersion Include="Microsoft.NET.ILLink.Task" Version="10.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Mono.Posix.NETStandard" Version="1.0.0" />
     <PackageVersion Include="SimpleExec" Version="13.0.0" />
     <PackageVersion Include="System.Text.Encoding.CodePages" Version="10.0.0" />
     <PackageVersion Include="System.Buffers" Version="4.6.1" />
     <PackageVersion Include="System.Memory" Version="4.6.3" />
-    <PackageVersion Include="xunit.v3" Version="3.2.1" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
     <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
     <GlobalPackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3" />

SharpCompress.sln

@@ -18,11 +18,12 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Config", "Config", "{CDB425
 		Directory.Build.props = Directory.Build.props
 		global.json = global.json
 		.editorconfig = .editorconfig
-		.gitignore = .gitignore
 		Directory.Packages.props = Directory.Packages.props
 		NuGet.config = NuGet.config
 		.github\workflows\nuget-release.yml = .github\workflows\nuget-release.yml
+		USAGE.md = USAGE.md
 		README.md = README.md
+		FORMATS.md = FORMATS.md
 		AGENTS.md = AGENTS.md
 	EndProjectSection
 EndProject

build/Program.cs

@@ -230,7 +230,7 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
     }
     else
     {
-        // Not tagged - create prerelease version
+        // Not tagged - create prerelease version based on next minor version
         var allTags = (await GetGitOutput("tag", "--list"))
             .Split('\n', StringSplitOptions.RemoveEmptyEntries)
             .Where(tag => Regex.IsMatch(tag.Trim(), @"^\d+\.\d+\.\d+$"))
@@ -240,22 +240,8 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
         var lastTag = allTags.OrderBy(tag => Version.Parse(tag)).LastOrDefault() ?? "0.0.0";
         var lastVersion = Version.Parse(lastTag);
 
-        // Determine version increment based on branch
-        var currentBranch = await GetCurrentBranch();
-        Version nextVersion;
-
-        if (currentBranch == "release")
-        {
-            // Release branch: increment patch version
-            nextVersion = new Version(lastVersion.Major, lastVersion.Minor, lastVersion.Build + 1);
-            Console.WriteLine($"Building prerelease for release branch (patch increment)");
-        }
-        else
-        {
-            // Master or other branches: increment minor version
-            nextVersion = new Version(lastVersion.Major, lastVersion.Minor + 1, 0);
-            Console.WriteLine($"Building prerelease for {currentBranch} branch (minor increment)");
-        }
+        // Increment minor version for next release
+        var nextVersion = new Version(lastVersion.Major, lastVersion.Minor + 1, 0);
 
         // Use commit count since the last version tag if available; otherwise, fall back to total count
         var revListArgs = allTags.Any() ? $"--count {lastTag}..HEAD" : "--count HEAD";
@@ -267,28 +253,6 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
     }
 }
 
-static async Task<string> GetCurrentBranch()
-{
-    // In GitHub Actions, GITHUB_REF_NAME contains the branch name
-    var githubRefName = Environment.GetEnvironmentVariable("GITHUB_REF_NAME");
-    if (!string.IsNullOrEmpty(githubRefName))
-    {
-        return githubRefName;
-    }
-
-    // Fallback to git command for local builds
-    try
-    {
-        var (output, _) = await ReadAsync("git", "branch --show-current");
-        return output.Trim();
-    }
-    catch (Exception ex)
-    {
-        Console.WriteLine($"Warning: Could not determine current branch: {ex.Message}");
-        return "unknown";
-    }
-}
-
 static async Task<string> GetGitOutput(string command, string args)
 {
     try

docs/API.md

@@ -8,49 +8,49 @@ Quick reference for commonly used SharpCompress APIs.
 
 ```csharp
 // Auto-detect format
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     // Works with Zip, Tar, GZip, Rar, 7Zip, etc.
 }
 
 // Specific format - Archive API
-using (var archive = ZipArchive.OpenArchive("file.zip"))
-using (var archive = TarArchive.OpenArchive("file.tar"))
-using (var archive = RarArchive.OpenArchive("file.rar"))
-using (var archive = SevenZipArchive.OpenArchive("file.7z"))
-using (var archive = GZipArchive.OpenArchive("file.gz"))
+using (var archive = ZipArchive.Open("file.zip"))
+using (var archive = TarArchive.Open("file.tar"))
+using (var archive = RarArchive.Open("file.rar"))
+using (var archive = SevenZipArchive.Open("file.7z"))
+using (var archive = GZipArchive.Open("file.gz"))
 
 // With options
-var options = new ReaderOptions
-{
+var options = new ReaderOptions 
+{ 
     Password = "password",
     LeaveStreamOpen = true,
     ArchiveEncoding = new ArchiveEncoding { Default = Encoding.GetEncoding(932) }
 };
-using (var archive = ZipArchive.OpenArchive("encrypted.zip", options))
+using (var archive = ZipArchive.Open("encrypted.zip", options))
 ```
 
 ### Creating Archives
 
 ```csharp
 // Writer Factory
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Zip, CompressionType.Deflate))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
 {
     // Write entries
 }
 
 // Specific writer
-using (var archive = ZipArchive.CreateArchive())
-using (var archive = TarArchive.CreateArchive())
-using (var archive = GZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
+using (var archive = TarArchive.Create())
+using (var archive = GZipArchive.Create())
 
 // With options
-var options = new WriterOptions(CompressionType.Deflate)
-{
+var options = new WriterOptions(CompressionType.Deflate) 
+{ 
     CompressionLevel = 9,
     LeaveStreamOpen = false
 };
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.SaveTo("output.zip", options);
 }
@@ -63,26 +63,26 @@ using (var archive = ZipArchive.CreateArchive())
 ### Reading/Extracting
 
 ```csharp
-using (var archive = ZipArchive.OpenArchive("file.zip"))
+using (var archive = ZipArchive.Open("file.zip"))
 {
     // Get all entries
-    IEnumerable<IArchiveEntry> entries = archive.Entries;
-
+    IEnumerable<IEntry> entries = archive.Entries;
+    
     // Find specific entry
     var entry = archive.Entries.FirstOrDefault(e => e.Key == "file.txt");
-
+    
     // Extract all
     archive.WriteToDirectory(@"C:\output", new ExtractionOptions
     {
         ExtractFullPath = true,
         Overwrite = true
     });
-
+    
     // Extract single entry
     var entry = archive.Entries.First();
     entry.WriteToFile(@"C:\output\file.txt");
     entry.WriteToFile(@"C:\output\file.txt", new ExtractionOptions { Overwrite = true });
-
+    
     // Get entry stream
     using (var stream = entry.OpenEntryStream())
     {
@@ -90,15 +90,8 @@ using (var archive = ZipArchive.OpenArchive("file.zip"))
     }
 }
 
-// Async extraction (requires IAsyncArchive)
-using (var asyncArchive = await ZipArchive.OpenAsyncArchive("file.zip"))
-{
-    await asyncArchive.WriteToDirectoryAsync(
-        @"C:\output",
-        new ExtractionOptions { ExtractFullPath = true, Overwrite = true },
-        cancellationToken: cancellationToken
-    );
-}
+// Async variants
+await archive.WriteToDirectoryAsync(@"C:\output", options, cancellationToken);
 using (var stream = await entry.OpenEntryStreamAsync(cancellationToken))
 {
     // ...
@@ -122,18 +115,18 @@ foreach (var entry in archive.Entries)
 ### Creating Archives
 
 ```csharp
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     // Add file
-    archive.AddEntry("file.txt", @"C:\source\file.txt");
-
+    archive.AddEntry("file.txt", "C:\\source\\file.txt");
+    
     // Add multiple files
-    archive.AddAllFromDirectory(@"C:\source");
-    archive.AddAllFromDirectory(@"C:\source", "*.txt");  // Pattern
-
+    archive.AddAllFromDirectory("C:\\source");
+    archive.AddAllFromDirectory("C:\\source", "*.txt");  // Pattern
+    
     // Save to file
     archive.SaveTo("output.zip", CompressionType.Deflate);
-
+    
     // Save to stream
     archive.SaveTo(outputStream, new WriterOptions(CompressionType.Deflate)
     {
@@ -151,18 +144,18 @@ using (var archive = ZipArchive.CreateArchive())
 
 ```csharp
 using (var stream = File.OpenRead("file.zip"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {
-        IArchiveEntry entry = reader.Entry;
-
+        IEntry entry = reader.Entry;
+        
         if (!entry.IsDirectory)
         {
             // Extract entry
             reader.WriteEntryToDirectory(@"C:\output");
             reader.WriteEntryToFile(@"C:\output\file.txt");
-
+            
             // Or get stream
             using (var entryStream = reader.OpenEntryStream())
             {
@@ -172,25 +165,16 @@ using (var reader = ReaderFactory.OpenReader(stream))
     }
 }
 
-// Async variants (use OpenAsyncReader to get IAsyncReader)
-using (var stream = File.OpenRead("file.zip"))
-using (var reader = await ReaderFactory.OpenAsyncReader(stream))
+// Async variants
+while (await reader.MoveToNextEntryAsync())
 {
-    while (await reader.MoveToNextEntryAsync())
-    {
-        await reader.WriteEntryToFileAsync(
-            @"C:\output\" + reader.Entry.Key,
-            cancellationToken: cancellationToken
-        );
-    }
-
-    // Async extraction of all entries
-    await reader.WriteAllToDirectoryAsync(
-        @"C:\output",
-        new ExtractionOptions { ExtractFullPath = true, Overwrite = true },
-        cancellationToken
-    );
+    await reader.WriteEntryToFileAsync(@"C:\output\" + reader.Entry.Key, cancellationToken);
 }
+
+// Async extraction
+await reader.WriteAllToDirectoryAsync(@"C:\output", 
+    new ExtractionOptions { ExtractFullPath = true, Overwrite = true },
+    cancellationToken);
 ```
 
 ---
@@ -201,7 +185,7 @@ using (var reader = await ReaderFactory.OpenAsyncReader(stream))
 
 ```csharp
 using (var stream = File.Create("output.zip"))
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Zip, CompressionType.Deflate))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
 {
     // Write single file
     using (var fileStream = File.OpenRead("source.txt"))
@@ -239,7 +223,7 @@ var options = new ReaderOptions
         Default = Encoding.GetEncoding(932)
     }
 };
-using (var archive = ZipArchive.OpenArchive("file.zip", options))
+using (var archive = ZipArchive.Open("file.zip", options))
 {
     // ...
 }
@@ -278,20 +262,15 @@ archive.WriteToDirectory(@"C:\output", options);
 // For creating archives
 CompressionType.None       // No compression (store)
 CompressionType.Deflate    // DEFLATE (default for ZIP/GZip)
-CompressionType.Deflate64  // Deflate64
 CompressionType.BZip2      // BZip2
 CompressionType.LZMA       // LZMA (for 7Zip, LZip, XZ)
 CompressionType.PPMd       // PPMd (for ZIP)
 CompressionType.Rar        // RAR compression (read-only)
-CompressionType.ZStandard  // ZStandard
-ArchiveType.Arc
-ArchiveType.Arj
-ArchiveType.Ace
 
-// For Tar archives with compression
-// Use WriterFactory to create compressed tar archives
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Tar, CompressionType.GZip))  // Tar.GZip
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Tar, CompressionType.BZip2)) // Tar.BZip2
+// For Tar archives
+// Use CompressionType in TarWriter constructor
+using (var writer = TarWriter(stream, CompressionType.GZip))  // Tar.GZip
+using (var writer = TarWriter(stream, CompressionType.BZip2)) // Tar.BZip2
 ```
 
 ### Archive Types
@@ -349,7 +328,7 @@ var progress = new Progress<ProgressReport>(report =>
 });
 
 var options = new ReaderOptions { Progress = progress };
-using (var archive = ZipArchive.OpenArchive("archive.zip", options))
+using (var archive = ZipArchive.Open("archive.zip", options))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -363,13 +342,11 @@ cts.CancelAfter(TimeSpan.FromMinutes(5));
 
 try
 {
-    using (var archive = await ZipArchive.OpenAsyncArchive("archive.zip"))
+    using (var archive = ZipArchive.Open("archive.zip"))
     {
-        await archive.WriteToDirectoryAsync(
-            @"C:\output",
+        await archive.WriteToDirectoryAsync(@"C:\output",
             new ExtractionOptions { ExtractFullPath = true, Overwrite = true },
-            cancellationToken: cts.Token
-        );
+            cts.Token);
     }
 }
 catch (OperationCanceledException)
@@ -381,23 +358,23 @@ catch (OperationCanceledException)
 ### Create with Custom Compression
 
 ```csharp
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.AddAllFromDirectory(@"D:\source");
     
     // Fastest
-    archive.SaveTo("fast.zip", new WriterOptions(CompressionType.Deflate)
-    {
-        CompressionLevel = 1
+    archive.SaveTo("fast.zip", new WriterOptions(CompressionType.Deflate) 
+    { 
+        CompressionLevel = 1 
     });
     
     // Balanced (default)
     archive.SaveTo("normal.zip", CompressionType.Deflate);
     
     // Best compression
-    archive.SaveTo("best.zip", new WriterOptions(CompressionType.Deflate)
-    {
-        CompressionLevel = 9
+    archive.SaveTo("best.zip", new WriterOptions(CompressionType.Deflate) 
+    { 
+        CompressionLevel = 9 
     });
 }
 ```
@@ -406,7 +383,7 @@ using (var archive = ZipArchive.CreateArchive())
 
 ```csharp
 using (var outputStream = new MemoryStream())
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     // Add content from memory
     using (var contentStream = new MemoryStream(Encoding.UTF8.GetBytes("Hello")))
@@ -425,7 +402,7 @@ using (var archive = ZipArchive.CreateArchive())
 ### Extract Specific Files
 
 ```csharp
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     var filesToExtract = new[] { "file1.txt", "file2.txt" };
     
@@ -439,7 +416,7 @@ using (var archive = ZipArchive.OpenArchive("archive.zip"))
 ### List Archive Contents
 
 ```csharp
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     foreach (var entry in archive.Entries)
     {
@@ -459,7 +436,7 @@ using (var archive = ZipArchive.OpenArchive("archive.zip"))
 
 ```csharp
 var stream = File.OpenRead("archive.zip");
-var archive = ZipArchive.OpenArchive(stream);
+var archive = ZipArchive.Open(stream);
 archive.WriteToDirectory(@"C:\output");
 // stream not disposed - leaked resource
 ```
@@ -468,7 +445,7 @@ archive.WriteToDirectory(@"C:\output");
 
 ```csharp
 using (var stream = File.OpenRead("archive.zip"))
-using (var archive = ZipArchive.OpenArchive(stream))
+using (var archive = ZipArchive.Open(stream))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -479,7 +456,7 @@ using (var archive = ZipArchive.OpenArchive(stream))
 
 ```csharp
 // Loading entire archive then iterating
-using (var archive = ZipArchive.OpenArchive("large.zip"))
+using (var archive = ZipArchive.Open("large.zip"))
 {
     var entries = archive.Entries.ToList();  // Loads all in memory
     foreach (var e in entries)
@@ -494,7 +471,7 @@ using (var archive = ZipArchive.OpenArchive("large.zip"))
 ```csharp
 // Streaming iteration
 using (var stream = File.OpenRead("large.zip"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {

docs/ARCHITECTURE.md

@@ -76,7 +76,7 @@ Factory classes for auto-detecting archive format and creating appropriate reade
 - Format-specific: `ZipFactory.cs`, `TarFactory.cs`, `RarFactory.cs`, etc.
 
 **How It Works:**
-1. `ReaderFactory.OpenReader(stream)` probes stream signatures
+1. `ReaderFactory.Open(stream)` probes stream signatures
 2. Identifies format by magic bytes
 3. Creates appropriate reader instance
 4. Returns generic `IReader` interface
@@ -142,7 +142,7 @@ Stream wrappers and utilities.
 **Example:**
 ```csharp
 // User calls factory
-using (var reader = ReaderFactory.OpenReader(stream))  // Returns IReader
+using (var reader = ReaderFactory.Open(stream))  // Returns IReader
 {
     while (reader.MoveToNextEntry())
     {
@@ -175,7 +175,7 @@ CompressionType.LZMA        // LZMA
 CompressionType.PPMd        // PPMd
 
 // Writer uses strategy pattern
-var archive = ZipArchive.CreateArchive();
+var archive = ZipArchive.Create();
 archive.SaveTo("output.zip", CompressionType.Deflate);   // Use Deflate
 archive.SaveTo("output.bz2", CompressionType.BZip2);    // Use BZip2
 ```
@@ -248,7 +248,7 @@ foreach (var entry in entries)
 }
 
 // Reader API - provides iterator
-IReader reader = ReaderFactory.OpenReader(stream);
+IReader reader = ReaderFactory.Open(stream);
 while (reader.MoveToNextEntry())
 {
     // Forward-only iteration - one entry at a time
@@ -381,7 +381,7 @@ public class NewFormatArchive : AbstractArchive
     private NewFormatHeader _header;
     private List<NewFormatEntry> _entries;
     
-    public static NewFormatArchive OpenArchive(Stream stream)
+    public static NewFormatArchive Open(Stream stream)
     {
         var archive = new NewFormatArchive();
         archive._header = NewFormatHeader.Read(stream);
@@ -442,8 +442,8 @@ public class NewFormatFactory : Factory, IArchiveFactory, IReaderFactory
     
     public static NewFormatFactory Instance { get; } = new();
     
-    public IArchive CreateArchive(Stream stream)
-        => NewFormatArchive.OpenArchive(stream);
+    public IArchive CreateArchive(Stream stream) 
+        => NewFormatArchive.Open(stream);
     
     public IReader CreateReader(Stream stream, ReaderOptions options)
         => new NewFormatReader(stream) { Options = options };
@@ -481,7 +481,7 @@ public class NewFormatTests : TestBase
     public void NewFormat_Extracts_Successfully()
     {
         var archivePath = Path.Combine(TEST_ARCHIVES_PATH, "archive.newformat");
-        using (var archive = NewFormatArchive.OpenArchive(archivePath))
+        using (var archive = NewFormatArchive.Open(archivePath))
         {
             archive.WriteToDirectory(SCRATCH_FILES_PATH);
             // Assert extraction
@@ -561,7 +561,7 @@ public class CustomStream : Stream
 ```csharp
 // Correct: Nested using blocks
 using (var fileStream = File.OpenRead("archive.zip"))
-using (var archive = ZipArchive.OpenArchive(fileStream))
+using (var archive = ZipArchive.Open(fileStream))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -570,7 +570,7 @@ using (var archive = ZipArchive.OpenArchive(fileStream))
 // Correct: Using with options
 var options = new ReaderOptions { LeaveStreamOpen = true };
 var stream = File.OpenRead("archive.zip");
-using (var archive = ZipArchive.OpenArchive(stream, options))
+using (var archive = ZipArchive.Open(stream, options))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -641,7 +641,7 @@ public void Archive_Extraction_Works()
     var testArchive = Path.Combine(TEST_ARCHIVES_PATH, "test.zip");
     
     // Act
-    using (var archive = ZipArchive.OpenArchive(testArchive))
+    using (var archive = ZipArchive.Open(testArchive))
     {
         archive.WriteToDirectory(SCRATCH_FILES_PATH);
     }

docs/DataDescriptorStream-RewindableStream-Fix.md

@@ -1,129 +0,0 @@
-# DataDescriptorStream and RewindableStream Fix
-
-## Summary
-
-Fixed the `Zip_Uncompressed_Read_All` test failure caused by incompatibility between `DataDescriptorStream` seeking requirements and the new `RewindableStream` wrapper used in `StreamingZipHeaderFactory`.
-
-## Problem Description
-
-### Symptom
-The test `Zip_Uncompressed_Read_All` was failing with:
-```
-System.NotSupportedException : Cannot seek outside buffered region.
-```
-
-### Root Cause
-
-The issue had two related aspects:
-
-#### 1. Double-Wrapping of RewindableStream
-
-`StreamingZipHeaderFactory.ReadStreamHeader()` was creating a new `RewindableStream` wrapper:
-```csharp
-var rewindableStream = new RewindableStream(stream);
-```
-
-When `ReaderFactory.OpenReader()` already wraps the input stream with `SeekableRewindableStream` (for seekable streams), this resulted in double-wrapping:
-```
-DataDescriptorStream
-  -> NonDisposingStream
-    -> RewindableStream (new, plain)  <-- created by ReadStreamHeader
-      -> SeekableRewindableStream     <-- created by ReaderFactory
-        -> FileStream
-```
-
-The inner plain `RewindableStream` lost the seeking capability of `SeekableRewindableStream`.
-
-#### 2. Recording State Interference
-
-Even after fixing the double-wrapping using `RewindableStream.EnsureSeekable()`, there was another issue:
-
-`StreamingZipHeaderFactory.ReadStreamHeader()` contains code to peek ahead when checking for zero-length files with `UsePostDataDescriptor`:
-
-```csharp
-rewindableStream.StartRecording();
-var nextHeaderBytes = reader.ReadUInt32();
-rewindableStream.Rewind(true);
-```
-
-This code was interfering with the recording state that `ReaderFactory.OpenReader()` had set up:
-
-1. `ReaderFactory.OpenReader()` calls `bStream.StartRecording()` at position 0
-2. Factory detection calls `StreamingZipHeaderFactory.ReadStreamHeader()` via `IsZipFile()`
-3. Inside `ReadStreamHeader`, the above code overwrites the recorded position
-4. `Rewind(true)` stops recording and seeks to the wrong position
-5. When control returns to `Factory.TryOpenReader()`, it calls `stream.Rewind(true)`, but recording is already stopped, so nothing happens
-6. The stream position is not at the beginning, causing subsequent reads to fail
-
-## Solution
-
-### Fix 1: Use EnsureSeekable instead of new RewindableStream
-
-Changed `StreamingZipHeaderFactory.ReadStreamHeader()` to use:
-```csharp
-var rewindableStream = RewindableStream.EnsureSeekable(stream);
-```
-
-This method:
-- Returns the existing `RewindableStream` if the stream is already one (avoids double-wrapping)
-- Creates a `SeekableRewindableStream` if the underlying stream is seekable
-- Creates a plain `RewindableStream` only for non-seekable streams
-
-### Fix 2: Use direct position save/restore for SeekableRewindableStream
-
-For the peek-ahead logic, changed the code to check for `SeekableRewindableStream` specifically and use direct position manipulation:
-
-```csharp
-if (rewindableStream is SeekableRewindableStream)
-{
-    // Direct position save/restore avoids interfering with caller's recording state
-    var savedPosition = rewindableStream.Position;
-    var nextHeaderBytes = reader.ReadUInt32();
-    rewindableStream.Position = savedPosition;
-    header.HasData = !IsHeader(nextHeaderBytes);
-}
-else
-{
-    // Plain RewindableStream was created fresh by EnsureSeekable, safe to use recording
-    rewindableStream.StartRecording();
-    var nextHeaderBytes = reader.ReadUInt32();
-    rewindableStream.Rewind(true);
-    header.HasData = !IsHeader(nextHeaderBytes);
-}
-```
-
-This approach:
-- For `SeekableRewindableStream` (reused from caller): Uses direct position save/restore to avoid clobbering the caller's recording state
-- For plain `RewindableStream` (freshly created): Uses the recording mechanism which is safe since the stream isn't shared
-
-## Files Changed
-
-- `src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.cs`
-- `src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.Async.cs`
-
-## Design Notes
-
-### Why not fix RewindableStream.CanSeek?
-
-`RewindableStream.CanSeek` returns `true` even though it can only seek within its buffered region. We considered changing this to `false`, but:
-1. It would be a breaking change for existing code that relies on `CanSeek`
-2. The `RewindableStream` does provide limited seeking capability (within buffer)
-3. Checking for `SeekableRewindableStream` specifically is more precise
-
-### Stream Wrapper Hierarchy
-
-Understanding the stream wrapper hierarchy is crucial:
-
-**For seekable source streams (e.g., FileStream):**
-```
-SeekableRewindableStream (full seeking via underlying stream)
-  -> FileStream
-```
-
-**For non-seekable source streams (e.g., decompression streams):**
-```
-RewindableStream (limited seeking via buffer)
-  -> DecompressionStream
-```
-
-`DataDescriptorStream` needs backward seeking to position the stream correctly after finding the data descriptor marker. This is why proper stream wrapper selection matters.

docs/ENCODING.md

@@ -27,7 +27,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("japanese.zip", options))
+using (var archive = ZipArchive.Open("japanese.zip", options))
 {
     foreach (var entry in archive.Entries)
     {
@@ -51,7 +51,7 @@ var options = new ReaderOptions
 {
     ArchiveEncoding = new ArchiveEncoding { Default = Encoding.GetEncoding(932) }
 };
-using (var archive = ZipArchive.OpenArchive("file.zip", options))
+using (var archive = ZipArchive.Open("file.zip", options))
 {
     // Use archive with correct encoding
 }
@@ -64,7 +64,7 @@ var options = new ReaderOptions
     ArchiveEncoding = new ArchiveEncoding { Default = Encoding.GetEncoding(932) }
 };
 using (var stream = File.OpenRead("file.zip"))
-using (var reader = ReaderFactory.OpenReader(stream, options))
+using (var reader = ReaderFactory.Open(stream, options))
 {
     while (reader.MoveToNextEntry())
     {
@@ -89,7 +89,7 @@ var options = new ReaderOptions
         Default = Encoding.GetEncoding(932)
     }
 };
-using (var archive = ZipArchive.OpenArchive("japanese.zip", options))
+using (var archive = ZipArchive.Open("japanese.zip", options))
 {
     // Correctly decodes Japanese filenames
 }
@@ -266,7 +266,7 @@ SharpCompress attempts to auto-detect encoding, but this isn't always reliable:
 
 ```csharp
 // Auto-detection (default)
-using (var archive = ZipArchive.OpenArchive("file.zip"))  // Uses UTF8 by default
+using (var archive = ZipArchive.Open("file.zip"))  // Uses UTF8 by default
 {
     // May show corrupted characters if archive uses different encoding
 }
@@ -276,7 +276,7 @@ var options = new ReaderOptions
 {
     ArchiveEncoding = new ArchiveEncoding { Default = Encoding.GetEncoding(932) }
 };
-using (var archive = ZipArchive.OpenArchive("file.zip", options))
+using (var archive = ZipArchive.Open("file.zip", options))
 {
     // Correct characters displayed
 }
@@ -324,7 +324,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("mixed.zip", options))
+using (var archive = ZipArchive.Open("mixed.zip", options))
 {
     foreach (var entry in archive.Entries)
     {
@@ -388,7 +388,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("japanese_files.zip", options))
+using (var archive = ZipArchive.Open("japanese_files.zip", options))
 {
     archive.WriteToDirectory(@"C:\output", new ExtractionOptions
     {
@@ -410,7 +410,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("french_files.zip", options))
+using (var archive = ZipArchive.Open("french_files.zip", options))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -428,7 +428,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("chinese_files.zip", options))
+using (var archive = ZipArchive.Open("chinese_files.zip", options))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -445,7 +445,7 @@ var options = new ReaderOptions
     }
 };
 
-using (var archive = ZipArchive.OpenArchive("russian_files.zip", options))
+using (var archive = ZipArchive.Open("russian_files.zip", options))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -463,7 +463,7 @@ var options = new ReaderOptions
 };
 
 using (var stream = File.OpenRead("japanese.zip"))
-using (var reader = ReaderFactory.OpenReader(stream, options))
+using (var reader = ReaderFactory.Open(stream, options))
 {
     while (reader.MoveToNextEntry())
     {
@@ -484,7 +484,7 @@ When creating archives, SharpCompress uses UTF8 by default (recommended):
 
 ```csharp
 // Create with UTF8 (default, recommended)
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.AddAllFromDirectory(@"D:\my_files");
     archive.SaveTo("output.zip", CompressionType.Deflate);

docs/PERFORMANCE.md

@@ -24,7 +24,7 @@ Choose the right API based on your use case:
 // - You need random access to entries
 // - Stream is seekable (file, MemoryStream)
 
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     // Random access - all entries available
     var specific = archive.Entries.FirstOrDefault(e => e.Key == "file.txt");
@@ -51,7 +51,7 @@ using (var archive = ZipArchive.OpenArchive("archive.zip"))
 // - Forward-only processing is acceptable
 
 using (var stream = File.OpenRead("large.zip"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {
@@ -129,7 +129,7 @@ For processing archives from downloads or pipes:
 ```csharp
 // Download stream (non-seekable)
 using (var httpStream = await httpClient.GetStreamAsync(url))
-using (var reader = ReaderFactory.OpenReader(httpStream))
+using (var reader = ReaderFactory.Open(httpStream))
 {
     // Process entries as they arrive
     while (reader.MoveToNextEntry())
@@ -159,14 +159,14 @@ Choose based on your constraints:
 ```csharp
 // Download then extract (requires disk space)
 var archivePath = await DownloadFile(url, @"C:\temp\archive.zip");
-using (var archive = ZipArchive.OpenArchive(archivePath))
+using (var archive = ZipArchive.Open(archivePath))
 {
     archive.WriteToDirectory(@"C:\output");
 }
 
 // Stream during download (on-the-fly extraction)
 using (var httpStream = await httpClient.GetStreamAsync(url))
-using (var reader = ReaderFactory.OpenReader(httpStream))
+using (var reader = ReaderFactory.Open(httpStream))
 {
     while (reader.MoveToNextEntry())
     {
@@ -198,7 +198,7 @@ Extracting File3 requires decompressing File1 and File2 first.
 
 **Random Extraction (Slow):**
 ```csharp
-using (var archive = RarArchive.OpenArchive("solid.rar"))
+using (var archive = RarArchive.Open("solid.rar"))
 {
     foreach (var entry in archive.Entries)
     {
@@ -210,7 +210,7 @@ using (var archive = RarArchive.OpenArchive("solid.rar"))
 
 **Sequential Extraction (Fast):**
 ```csharp
-using (var archive = RarArchive.OpenArchive("solid.rar"))
+using (var archive = RarArchive.Open("solid.rar"))
 {
     // Method 1: Use WriteToDirectory (recommended)
     archive.WriteToDirectory(@"C:\output", new ExtractionOptions
@@ -256,7 +256,7 @@ using (var archive = RarArchive.OpenArchive("solid.rar"))
 // Level 9 = Slowest, best compression
 
 // Write with different compression levels
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.AddAllFromDirectory(@"D:\data");
     
@@ -293,7 +293,7 @@ using (var archive = ZipArchive.CreateArchive())
 // Smaller block size = lower memory, faster
 // Larger block size = better compression, slower
 
-using (var archive = TarArchive.CreateArchive())
+using (var archive = TarArchive.Create())
 {
     archive.AddAllFromDirectory(@"D:\data");
     
@@ -313,7 +313,7 @@ LZMA compression is very powerful but memory-intensive:
 // - Better compression: larger dictionary
 
 // Preset via CompressionType
-using (var archive = TarArchive.CreateArchive())
+using (var archive = TarArchive.Create())
 {
     archive.AddAllFromDirectory(@"D:\data");
     archive.SaveTo("archive.tar.xz", CompressionType.LZMA);  // Default settings
@@ -333,7 +333,7 @@ Async is beneficial when:
 
 ```csharp
 // Async extraction (non-blocking)
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     await archive.WriteToDirectoryAsync(
         @"C:\output",
@@ -353,7 +353,7 @@ Async doesn't improve performance for:
 
 ```csharp
 // Sync extraction (simpler, same performance on fast I/O)
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     archive.WriteToDirectory(
         @"C:\output",
@@ -373,7 +373,7 @@ cts.CancelAfter(TimeSpan.FromMinutes(5));
 
 try
 {
-    using (var archive = ZipArchive.OpenArchive("archive.zip"))
+    using (var archive = ZipArchive.Open("archive.zip"))
     {
         await archive.WriteToDirectoryAsync(
             @"C:\output",
@@ -408,14 +408,14 @@ catch (OperationCanceledException)
 // ✗ Slow - opens each archive separately
 foreach (var file in files)
 {
-    using (var archive = ZipArchive.OpenArchive("archive.zip"))
+    using (var archive = ZipArchive.Open("archive.zip"))
     {
         archive.WriteToDirectory(@"C:\output");
     }
 }
 
 // ✓ Better - process multiple entries at once
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     archive.WriteToDirectory(@"C:\output");
 }
@@ -425,7 +425,7 @@ using (var archive = ZipArchive.OpenArchive("archive.zip"))
 
 ```csharp
 var sw = Stopwatch.StartNew();
-using (var archive = ZipArchive.OpenArchive("large.zip"))
+using (var archive = ZipArchive.Open("large.zip"))
 {
     archive.WriteToDirectory(@"C:\output");
 }

docs/USAGE.md

@@ -48,7 +48,7 @@ Also, look over the tests for more thorough [examples](https://github.com/adamha
 
 ### Create Zip Archive from multiple files
 ```C#
-using(var archive = ZipArchive.CreateArchive())
+using(var archive = ZipArchive.Create())
 {
     archive.AddEntry("file01.txt", "C:\\file01.txt");
     archive.AddEntry("file02.txt", "C:\\file02.txt");
@@ -61,7 +61,7 @@ using(var archive = ZipArchive.CreateArchive())
 ### Create Zip Archive from all files in a directory to a file
 
 ```C#
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.AddAllFromDirectory("D:\\temp");
     archive.SaveTo("C:\\temp.zip", CompressionType.Deflate);
@@ -72,7 +72,7 @@ using (var archive = ZipArchive.CreateArchive())
 
 ```C#
 var memoryStream = new MemoryStream();
-using (var archive = ZipArchive.CreateArchive())
+using (var archive = ZipArchive.Create())
 {
     archive.AddAllFromDirectory("D:\\temp");
     archive.SaveTo(memoryStream, new WriterOptions(CompressionType.Deflate)
@@ -90,7 +90,7 @@ Note: Extracting a solid rar or 7z file needs to be done in sequential order to
 `ExtractAllEntries` is primarily intended for solid archives (like solid Rar) or 7Zip archives, where sequential extraction provides the best performance. For general/simple extraction with any supported archive type, use `archive.WriteToDirectory()` instead.
 
 ```C#
-using (var archive = RarArchive.OpenArchive("Test.rar"))
+using (var archive = RarArchive.Open("Test.rar"))
 {
     // Simple extraction with RarArchive; this WriteToDirectory pattern works for all archive types
     archive.WriteToDirectory(@"D:\temp", new ExtractionOptions()
@@ -104,7 +104,7 @@ using (var archive = RarArchive.OpenArchive("Test.rar"))
 ### Iterate over all files from a Rar file using RarArchive
 
 ```C#
-using (var archive = RarArchive.OpenArchive("Test.rar"))
+using (var archive = RarArchive.Open("Test.rar"))
 {
     foreach (var entry in archive.Entries.Where(entry => !entry.IsDirectory))
     {
@@ -126,7 +126,7 @@ var progress = new Progress<ProgressReport>(report =>
     Console.WriteLine($"Extracting {report.EntryPath}: {report.PercentComplete}%");
 });
 
-using (var archive = RarArchive.OpenArchive("archive.rar", new ReaderOptions { Progress = progress })) // Must be solid Rar or 7Zip
+using (var archive = RarArchive.Open("archive.rar", new ReaderOptions { Progress = progress })) // Must be solid Rar or 7Zip
 {
     archive.WriteToDirectory(@"D:\output", new ExtractionOptions()
     {
@@ -140,7 +140,7 @@ using (var archive = RarArchive.OpenArchive("archive.rar", new ReaderOptions { P
 
 ```C#
 using (Stream stream = File.OpenRead("Tar.tar.bz2"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {
@@ -161,7 +161,7 @@ using (var reader = ReaderFactory.OpenReader(stream))
 
 ```C#
 using (Stream stream = File.OpenRead("Tar.tar.bz2"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {
@@ -180,7 +180,7 @@ using (var reader = ReaderFactory.OpenReader(stream))
 
 ```C#
 using (Stream stream = File.OpenWrite("C:\\temp.tgz"))
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)
+using (var writer = WriterFactory.Open(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)
                                                 {
                                                     LeaveOpenStream = true
                                                 }))
@@ -199,7 +199,7 @@ opts.ArchiveEncoding.CustomDecoder = (data, x, y) =>
 {
     return encoding.GetString(data);
 };
-var tr = SharpCompress.Archives.Zip.ZipArchive.OpenArchive("test.zip", opts);
+var tr = SharpCompress.Archives.Zip.ZipArchive.Open("test.zip", opts);
 foreach(var entry in tr.Entries)
 {
     Console.WriteLine($"{entry.Key}");
@@ -213,7 +213,7 @@ foreach(var entry in tr.Entries)
 **Extract single entry asynchronously:**
 ```C#
 using (Stream stream = File.OpenRead("archive.zip"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     while (reader.MoveToNextEntry())
     {
@@ -234,7 +234,7 @@ using (var reader = ReaderFactory.OpenReader(stream))
 **Extract all entries asynchronously:**
 ```C#
 using (Stream stream = File.OpenRead("archive.tar.gz"))
-using (var reader = ReaderFactory.OpenReader(stream))
+using (var reader = ReaderFactory.Open(stream))
 {
     await reader.WriteAllToDirectoryAsync(
         @"D:\temp",
@@ -250,7 +250,7 @@ using (var reader = ReaderFactory.OpenReader(stream))
 
 **Open and process entry stream asynchronously:**
 ```C#
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     foreach (var entry in archive.Entries.Where(e => !e.IsDirectory))
     {
@@ -268,7 +268,7 @@ using (var archive = ZipArchive.OpenArchive("archive.zip"))
 **Write single file asynchronously:**
 ```C#
 using (Stream archiveStream = File.OpenWrite("output.zip"))
-using (var writer = WriterFactory.OpenWriter(archiveStream, ArchiveType.Zip, CompressionType.Deflate))
+using (var writer = WriterFactory.Open(archiveStream, ArchiveType.Zip, CompressionType.Deflate))
 {
     using (Stream fileStream = File.OpenRead("input.txt"))
     {
@@ -280,7 +280,7 @@ using (var writer = WriterFactory.OpenWriter(archiveStream, ArchiveType.Zip, Com
 **Write entire directory asynchronously:**
 ```C#
 using (Stream stream = File.OpenWrite("backup.tar.gz"))
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)))
 {
     await writer.WriteAllAsync(
         @"D:\files",
@@ -299,7 +299,7 @@ var cts = new CancellationTokenSource();
 cts.CancelAfter(TimeSpan.FromMinutes(5));
 
 using (Stream stream = File.OpenWrite("archive.zip"))
-using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Zip, CompressionType.Deflate))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
 {
     try
     {
@@ -316,7 +316,7 @@ using (var writer = WriterFactory.OpenWriter(stream, ArchiveType.Zip, Compressio
 
 **Extract from archive asynchronously:**
 ```C#
-using (var archive = ZipArchive.OpenArchive("archive.zip"))
+using (var archive = ZipArchive.Open("archive.zip"))
 {
     // Simple async extraction - works for all archive types
     await archive.WriteToDirectoryAsync(

src/SharpCompress/Algorithms/Adler32.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Apache License, Version 2.0.
 
-#if !LEGACY_DOTNET
+#if !NETSTANDARD2_0 && !NETSTANDARD2_1 && !NETFRAMEWORK
 #define SUPPORTS_RUNTIME_INTRINSICS
 #define SUPPORTS_HOTPATH
 #endif

src/SharpCompress/Archives/AbstractArchive.Async.cs

@@ -1,103 +0,0 @@
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives;
-
-public abstract partial class AbstractArchive<TEntry, TVolume>
-    where TEntry : IArchiveEntry
-    where TVolume : IVolume
-{
-    #region Async Support
-
-    // Async properties
-    public virtual IAsyncEnumerable<TEntry> EntriesAsync => _lazyEntriesAsync;
-
-    public IAsyncEnumerable<TVolume> VolumesAsync => _lazyVolumesAsync;
-
-    protected virtual async IAsyncEnumerable<TEntry> LoadEntriesAsync(
-        IAsyncEnumerable<TVolume> volumes
-    )
-    {
-        foreach (var item in LoadEntries(await volumes.ToListAsync()))
-        {
-            yield return item;
-        }
-    }
-
-    public virtual async ValueTask DisposeAsync()
-    {
-        if (!_disposed)
-        {
-            await foreach (var v in _lazyVolumesAsync)
-            {
-                v.Dispose();
-            }
-            foreach (var v in _lazyEntriesAsync.GetLoaded().Cast<Entry>())
-            {
-                v.Close();
-            }
-            _sourceStream?.Dispose();
-
-            _disposed = true;
-        }
-    }
-
-    private async ValueTask EnsureEntriesLoadedAsync()
-    {
-        await _lazyEntriesAsync.EnsureFullyLoaded();
-        await _lazyVolumesAsync.EnsureFullyLoaded();
-    }
-
-    private async IAsyncEnumerable<IArchiveEntry> EntriesAsyncCast()
-    {
-        await foreach (var entry in EntriesAsync)
-        {
-            yield return entry;
-        }
-    }
-
-    IAsyncEnumerable<IArchiveEntry> IAsyncArchive.EntriesAsync => EntriesAsyncCast();
-
-    IAsyncEnumerable<IVolume> IAsyncArchive.VolumesAsync => VolumesAsyncCast();
-
-    private async IAsyncEnumerable<IVolume> VolumesAsyncCast()
-    {
-        await foreach (var volume in _lazyVolumesAsync)
-        {
-            yield return volume;
-        }
-    }
-
-    public async ValueTask<IAsyncReader> ExtractAllEntriesAsync()
-    {
-        if (!await IsSolidAsync() && Type != ArchiveType.SevenZip)
-        {
-            throw new SharpCompressException(
-                "ExtractAllEntries can only be used on solid archives or 7Zip archives (which require random access)."
-            );
-        }
-        await EnsureEntriesLoadedAsync();
-        return await CreateReaderForSolidExtractionAsync();
-    }
-
-    public virtual ValueTask<bool> IsSolidAsync() => new(false);
-
-    public async ValueTask<bool> IsCompleteAsync()
-    {
-        await EnsureEntriesLoadedAsync();
-        return await EntriesAsync.AllAsync(x => x.IsComplete);
-    }
-
-    public async ValueTask<long> TotalSizeAsync() =>
-        await EntriesAsync.AggregateAsync(0L, (total, cf) => total + cf.CompressedSize);
-
-    public async ValueTask<long> TotalUncompressedSizeAsync() =>
-        await EntriesAsync.AggregateAsync(0L, (total, cf) => total + cf.Size);
-
-    public ValueTask<bool> IsEncryptedAsync() => new(IsEncrypted);
-
-    #endregion
-}

src/SharpCompress/Archives/AbstractArchive.cs

@@ -7,7 +7,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
+public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     where TEntry : IArchiveEntry
     where TVolume : IVolume
 {
@@ -16,10 +16,6 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     private bool _disposed;
     private readonly SourceStream? _sourceStream;
 
-    // Async fields - kept in original file per refactoring rules
-    private readonly LazyAsyncReadOnlyCollection<TVolume> _lazyVolumesAsync;
-    private readonly LazyAsyncReadOnlyCollection<TEntry> _lazyEntriesAsync;
-
     protected ReaderOptions ReaderOptions { get; }
 
     internal AbstractArchive(ArchiveType type, SourceStream sourceStream)
@@ -72,7 +68,7 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     /// <summary>
     /// The total size of the files as uncompressed in the archive.
     /// </summary>
-    public virtual long TotalUncompressedSize =>
+    public virtual long TotalUncompressSize =>
         Entries.Aggregate(0L, (total, cf) => total + cf.Size);
 
     protected abstract IEnumerable<TVolume> LoadVolumes(SourceStream sourceStream);
@@ -81,6 +77,16 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     protected virtual IAsyncEnumerable<TVolume> LoadVolumesAsync(SourceStream sourceStream) =>
         LoadVolumes(sourceStream).ToAsyncEnumerable();
 
+    protected virtual async IAsyncEnumerable<TEntry> LoadEntriesAsync(
+        IAsyncEnumerable<TVolume> volumes
+    )
+    {
+        foreach (var item in LoadEntries(await volumes.ToListAsync()))
+        {
+            yield return item;
+        }
+    }
+
     IEnumerable<IArchiveEntry> IArchive.Entries => Entries.Cast<IArchiveEntry>();
 
     IEnumerable<IVolume> IArchive.Volumes => _lazyVolumes.Cast<IVolume>();
@@ -150,4 +156,67 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
             return Entries.All(x => x.IsComplete);
         }
     }
+
+    #region Async Support
+
+    private readonly LazyAsyncReadOnlyCollection<TVolume> _lazyVolumesAsync;
+    private readonly LazyAsyncReadOnlyCollection<TEntry> _lazyEntriesAsync;
+
+    public virtual async ValueTask DisposeAsync()
+    {
+        if (!_disposed)
+        {
+            await foreach (var v in _lazyVolumesAsync)
+            {
+                v.Dispose();
+            }
+            foreach (var v in _lazyEntriesAsync.GetLoaded().Cast<Entry>())
+            {
+                v.Close();
+            }
+            _sourceStream?.Dispose();
+
+            _disposed = true;
+        }
+    }
+
+    private async ValueTask EnsureEntriesLoadedAsync()
+    {
+        await _lazyEntriesAsync.EnsureFullyLoaded();
+        await _lazyVolumesAsync.EnsureFullyLoaded();
+    }
+
+    public virtual IAsyncEnumerable<TEntry> EntriesAsync => _lazyEntriesAsync;
+    IAsyncEnumerable<IArchiveEntry> IAsyncArchive.EntriesAsync =>
+        EntriesAsync.Cast<TEntry, IArchiveEntry>();
+
+    public IAsyncEnumerable<IVolume> VolumesAsync => _lazyVolumesAsync.Cast<TVolume, IVolume>();
+
+    public async ValueTask<IAsyncReader> ExtractAllEntriesAsync()
+    {
+        if (!IsSolid && Type != ArchiveType.SevenZip)
+        {
+            throw new SharpCompressException(
+                "ExtractAllEntries can only be used on solid archives or 7Zip archives (which require random access)."
+            );
+        }
+        await EnsureEntriesLoadedAsync();
+        return await CreateReaderForSolidExtractionAsync();
+    }
+
+    public virtual ValueTask<bool> IsSolidAsync() => new(false);
+
+    public async ValueTask<bool> IsCompleteAsync()
+    {
+        await EnsureEntriesLoadedAsync();
+        return await EntriesAsync.All(x => x.IsComplete);
+    }
+
+    public async ValueTask<long> TotalSizeAsync() =>
+        await EntriesAsync.Aggregate(0L, (total, cf) => total + cf.CompressedSize);
+
+    public async ValueTask<long> TotalUncompressSizeAsync() =>
+        await EntriesAsync.Aggregate(0L, (total, cf) => total + cf.Size);
+
+    #endregion
 }

src/SharpCompress/Archives/AbstractWritableArchive.Async.cs

@@ -1,123 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Writers;
-
-namespace SharpCompress.Archives;
-
-public abstract partial class AbstractWritableArchive<TEntry, TVolume>
-    where TEntry : IArchiveEntry
-    where TVolume : IVolume
-{
-    // Async property moved from main file
-    private IAsyncEnumerable<TEntry> OldEntriesAsync =>
-        base.EntriesAsync.Where(x => !removedEntries.Contains(x));
-
-    private async ValueTask RebuildModifiedCollectionAsync()
-    {
-        if (pauseRebuilding)
-        {
-            return;
-        }
-        hasModifications = true;
-        newEntries.RemoveAll(v => removedEntries.Contains(v));
-        modifiedEntries.Clear();
-        await foreach (var entry in OldEntriesAsync)
-        {
-            modifiedEntries.Add(entry);
-        }
-        modifiedEntries.AddRange(newEntries);
-    }
-
-    public async ValueTask RemoveEntryAsync(TEntry entry)
-    {
-        if (!removedEntries.Contains(entry))
-        {
-            removedEntries.Add(entry);
-            await RebuildModifiedCollectionAsync();
-        }
-    }
-
-    private async ValueTask<bool> DoesKeyMatchExistingAsync(
-        string key,
-        CancellationToken cancellationToken
-    )
-    {
-        await foreach (
-            var entry in EntriesAsync.WithCancellation(cancellationToken).ConfigureAwait(false)
-        )
-        {
-            var path = entry.Key;
-            if (path is null)
-            {
-                continue;
-            }
-            var p = path.Replace('/', '\\');
-            if (p.Length > 0 && p[0] == '\\')
-            {
-                p = p.Substring(1);
-            }
-            return string.Equals(p, key, StringComparison.OrdinalIgnoreCase);
-        }
-        return false;
-    }
-
-    public async ValueTask<TEntry> AddEntryAsync(
-        string key,
-        Stream source,
-        bool closeStream,
-        long size = 0,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (key.Length > 0 && key[0] is '/' or '\\')
-        {
-            key = key.Substring(1);
-        }
-        if (await DoesKeyMatchExistingAsync(key, cancellationToken).ConfigureAwait(false))
-        {
-            throw new ArchiveException("Cannot add entry with duplicate key: " + key);
-        }
-        var entry = CreateEntry(key, source, size, modified, closeStream);
-        newEntries.Add(entry);
-        await RebuildModifiedCollectionAsync();
-        return entry;
-    }
-
-    public async ValueTask<TEntry> AddDirectoryEntryAsync(
-        string key,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (key.Length > 0 && key[0] is '/' or '\\')
-        {
-            key = key.Substring(1);
-        }
-        if (await DoesKeyMatchExistingAsync(key, cancellationToken).ConfigureAwait(false))
-        {
-            throw new ArchiveException("Cannot add entry with duplicate key: " + key);
-        }
-        var entry = CreateDirectoryEntry(key, modified);
-        newEntries.Add(entry);
-        await RebuildModifiedCollectionAsync();
-        return entry;
-    }
-
-    public async ValueTask SaveToAsync(
-        Stream stream,
-        WriterOptions options,
-        CancellationToken cancellationToken = default
-    )
-    {
-        //reset streams of new entries
-        newEntries.Cast<IWritableArchiveEntry>().ForEach(x => x.Stream.Seek(0, SeekOrigin.Begin));
-        await SaveToAsync(stream, options, OldEntriesAsync, newEntries, cancellationToken)
-            .ConfigureAwait(false);
-    }
-}

src/SharpCompress/Archives/AbstractWritableArchive.cs

@@ -10,10 +10,9 @@ using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
 
-public abstract partial class AbstractWritableArchive<TEntry, TVolume>
+public abstract class AbstractWritableArchive<TEntry, TVolume>
     : AbstractArchive<TEntry, TVolume>,
-        IWritableArchive,
-        IWritableAsyncArchive
+        IWritableArchive
     where TEntry : IArchiveEntry
     where TVolume : IVolume
 {
@@ -140,24 +139,6 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         return false;
     }
 
-    ValueTask IWritableAsyncArchive.RemoveEntryAsync(IArchiveEntry entry) =>
-        RemoveEntryAsync((TEntry)entry);
-
-    async ValueTask<IArchiveEntry> IWritableAsyncArchive.AddEntryAsync(
-        string key,
-        Stream source,
-        bool closeStream,
-        long size,
-        DateTime? modified,
-        CancellationToken cancellationToken
-    ) => await AddEntryAsync(key, source, closeStream, size, modified, cancellationToken);
-
-    async ValueTask<IArchiveEntry> IWritableAsyncArchive.AddDirectoryEntryAsync(
-        string key,
-        DateTime? modified,
-        CancellationToken cancellationToken
-    ) => await AddDirectoryEntryAsync(key, modified, cancellationToken);
-
     public TEntry AddDirectoryEntry(string key, DateTime? modified = null)
     {
         if (key.Length > 0 && key[0] is '/' or '\\')
@@ -181,6 +162,18 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         SaveTo(stream, options, OldEntries, newEntries);
     }
 
+    public async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    )
+    {
+        //reset streams of new entries
+        newEntries.Cast<IWritableArchiveEntry>().ForEach(x => x.Stream.Seek(0, SeekOrigin.Begin));
+        await SaveToAsync(stream, options, OldEntries, newEntries, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     protected TEntry CreateEntry(
         string key,
         Stream source,
@@ -218,7 +211,7 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
     protected abstract ValueTask SaveToAsync(
         Stream stream,
         WriterOptions options,
-        IAsyncEnumerable<TEntry> oldEntries,
+        IEnumerable<TEntry> oldEntries,
         IEnumerable<TEntry> newEntries,
         CancellationToken cancellationToken = default
     );

src/SharpCompress/Archives/ArchiveFactory.Async.cs

@@ -1,158 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Factories;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives;
-
-public static partial class ArchiveFactory
-{
-    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        readerOptions ??= new ReaderOptions();
-        stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
-        var factory = await FindFactoryAsync<IArchiveFactory>(stream, cancellationToken);
-        return factory.OpenAsyncArchive(stream, readerOptions);
-    }
-
-    public static ValueTask<IAsyncArchive> OpenAsyncArchive(
-        string filePath,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenAsyncArchive(new FileInfo(filePath), options, cancellationToken);
-    }
-
-    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        options ??= new ReaderOptions { LeaveStreamOpen = false };
-
-        var factory = await FindFactoryAsync<IArchiveFactory>(fileInfo, cancellationToken);
-        return factory.OpenAsyncArchive(fileInfo, options);
-    }
-
-    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var filesArray = fileInfos.ToArray();
-        if (filesArray.Length == 0)
-        {
-            throw new InvalidOperationException("No files to open");
-        }
-
-        var fileInfo = filesArray[0];
-        if (filesArray.Length == 1)
-        {
-            return await OpenAsyncArchive(fileInfo, options, cancellationToken);
-        }
-
-        fileInfo.NotNull(nameof(fileInfo));
-        options ??= new ReaderOptions { LeaveStreamOpen = false };
-
-        var factory = await FindFactoryAsync<IMultiArchiveFactory>(fileInfo, cancellationToken);
-        return factory.OpenAsyncArchive(filesArray, options, cancellationToken);
-    }
-
-    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        streams.NotNull(nameof(streams));
-        var streamsArray = streams.ToArray();
-        if (streamsArray.Length == 0)
-        {
-            throw new InvalidOperationException("No streams");
-        }
-
-        var firstStream = streamsArray[0];
-        if (streamsArray.Length == 1)
-        {
-            return await OpenAsyncArchive(firstStream, options, cancellationToken);
-        }
-
-        firstStream.NotNull(nameof(firstStream));
-        options ??= new ReaderOptions();
-
-        var factory = await FindFactoryAsync<IMultiArchiveFactory>(firstStream, cancellationToken);
-        return factory.OpenAsyncArchive(streamsArray, options);
-    }
-
-    public static ValueTask<T> FindFactoryAsync<T>(
-        string path,
-        CancellationToken cancellationToken = default
-    )
-        where T : IFactory
-    {
-        path.NotNullOrEmpty(nameof(path));
-        return FindFactoryAsync<T>(new FileInfo(path), cancellationToken);
-    }
-
-    private static async ValueTask<T> FindFactoryAsync<T>(
-        FileInfo finfo,
-        CancellationToken cancellationToken
-    )
-        where T : IFactory
-    {
-        finfo.NotNull(nameof(finfo));
-        using Stream stream = finfo.OpenRead();
-        return await FindFactoryAsync<T>(stream, cancellationToken);
-    }
-
-    private static async ValueTask<T> FindFactoryAsync<T>(
-        Stream stream,
-        CancellationToken cancellationToken
-    )
-        where T : IFactory
-    {
-        stream.NotNull(nameof(stream));
-        if (!stream.CanRead || !stream.CanSeek)
-        {
-            throw new ArgumentException("Stream should be readable and seekable");
-        }
-
-        var factories = Factory.Factories.OfType<T>();
-
-        var startPosition = stream.Position;
-
-        foreach (var factory in factories)
-        {
-            stream.Seek(startPosition, SeekOrigin.Begin);
-
-            if (await factory.IsArchiveAsync(stream, cancellationToken: cancellationToken))
-            {
-                stream.Seek(startPosition, SeekOrigin.Begin);
-
-                return factory;
-            }
-        }
-
-        var extensions = string.Join(", ", factories.Select(item => item.Name));
-
-        throw new InvalidOperationException(
-            $"Cannot determine compressed stream type. Supported Archive Formats: {extensions}"
-        );
-    }
-}

src/SharpCompress/Archives/ArchiveFactory.cs

@@ -11,16 +11,44 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public static partial class ArchiveFactory
+public static class ArchiveFactory
 {
-    public static IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
+    /// <summary>
+    /// Opens an Archive for random access
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <returns></returns>
+    public static IArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
         readerOptions ??= new ReaderOptions();
         stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
-        return FindFactory<IArchiveFactory>(stream).OpenArchive(stream, readerOptions);
+        return FindFactory<IArchiveFactory>(stream).Open(stream, readerOptions);
     }
 
-    public static IWritableArchive CreateArchive(ArchiveType type)
+    /// <summary>
+    /// Opens an Archive for random access asynchronously
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    /// <returns></returns>
+    public static async ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        readerOptions ??= new ReaderOptions();
+        stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
+        var factory = await FindFactoryAsync<IArchiveFactory>(stream, cancellationToken)
+            .ConfigureAwait(false);
+        return await factory
+            .OpenAsync(stream, readerOptions, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
+    public static IWritableArchive Create(ArchiveType type)
     {
         var factory = Factory
             .Factories.OfType<IWriteableArchiveFactory>()
@@ -28,28 +56,106 @@ public static partial class ArchiveFactory
 
         if (factory != null)
         {
-            return factory.CreateArchive();
+            return factory.CreateWriteableArchive();
         }
 
         throw new NotSupportedException("Cannot create Archives of type: " + type);
     }
 
-    public static IArchive OpenArchive(string filePath, ReaderOptions? options = null)
+    /// <summary>
+    /// Constructor expects a filepath to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="options"></param>
+    public static IArchive Open(string filePath, ReaderOptions? options = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), options);
+        return Open(new FileInfo(filePath), options);
     }
 
-    public static IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? options = null)
+    /// <summary>
+    /// Opens an Archive from a filepath asynchronously.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        string filePath,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return OpenAsync(new FileInfo(filePath), options, cancellationToken);
+    }
+
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="options"></param>
+    public static IArchive Open(FileInfo fileInfo, ReaderOptions? options = null)
     {
         options ??= new ReaderOptions { LeaveStreamOpen = false };
 
-        return FindFactory<IArchiveFactory>(fileInfo).OpenArchive(fileInfo, options);
+        return FindFactory<IArchiveFactory>(fileInfo).Open(fileInfo, options);
     }
 
-    public static IArchive OpenArchive(
+    /// <summary>
+    /// Opens an Archive from a FileInfo object asynchronously.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        var factory = await FindFactoryAsync<IArchiveFactory>(fileInfo, cancellationToken)
+            .ConfigureAwait(false);
+        return await factory.OpenAsync(fileInfo, options, cancellationToken).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Constructor with IEnumerable FileInfo objects, multi and split support.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="options"></param>
+    public static IArchive Open(IEnumerable<FileInfo> fileInfos, ReaderOptions? options = null)
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var filesArray = fileInfos.ToArray();
+        if (filesArray.Length == 0)
+        {
+            throw new InvalidOperationException("No files to open");
+        }
+
+        var fileInfo = filesArray[0];
+        if (filesArray.Length == 1)
+        {
+            return Open(fileInfo, options);
+        }
+
+        fileInfo.NotNull(nameof(fileInfo));
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        return FindFactory<IMultiArchiveFactory>(fileInfo).Open(filesArray, options);
+    }
+
+    /// <summary>
+    /// Opens a multi-part archive from files asynchronously.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async ValueTask<IAsyncArchive> OpenAsync(
         IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? options = null
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
     )
     {
         fileInfos.NotNull(nameof(fileInfos));
@@ -62,16 +168,24 @@ public static partial class ArchiveFactory
         var fileInfo = filesArray[0];
         if (filesArray.Length == 1)
         {
-            return OpenArchive(fileInfo, options);
+            return await OpenAsync(fileInfo, options, cancellationToken).ConfigureAwait(false);
         }
 
         fileInfo.NotNull(nameof(fileInfo));
         options ??= new ReaderOptions { LeaveStreamOpen = false };
 
-        return FindFactory<IMultiArchiveFactory>(fileInfo).OpenArchive(filesArray, options);
+        var factory = FindFactory<IMultiArchiveFactory>(fileInfo);
+        return await factory
+            .OpenAsync(filesArray, options, cancellationToken)
+            .ConfigureAwait(false);
     }
 
-    public static IArchive OpenArchive(IEnumerable<Stream> streams, ReaderOptions? options = null)
+    /// <summary>
+    /// Constructor with IEnumerable FileInfo objects, multi and split support.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="options"></param>
+    public static IArchive Open(IEnumerable<Stream> streams, ReaderOptions? options = null)
     {
         streams.NotNull(nameof(streams));
         var streamsArray = streams.ToArray();
@@ -83,34 +197,64 @@ public static partial class ArchiveFactory
         var firstStream = streamsArray[0];
         if (streamsArray.Length == 1)
         {
-            return OpenArchive(firstStream, options);
+            return Open(firstStream, options);
         }
 
         firstStream.NotNull(nameof(firstStream));
         options ??= new ReaderOptions();
 
-        return FindFactory<IMultiArchiveFactory>(firstStream).OpenArchive(streamsArray, options);
+        return FindFactory<IMultiArchiveFactory>(firstStream).Open(streamsArray, options);
     }
 
+    /// <summary>
+    /// Opens a multi-part archive from streams asynchronously.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async ValueTask<IAsyncArchive> OpenAsync(
+        IEnumerable<Stream> streams,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        streams.NotNull(nameof(streams));
+        var streamsArray = streams.ToArray();
+        if (streamsArray.Length == 0)
+        {
+            throw new InvalidOperationException("No streams");
+        }
+
+        var firstStream = streamsArray[0];
+        if (streamsArray.Length == 1)
+        {
+            return await OpenAsync(firstStream, options, cancellationToken).ConfigureAwait(false);
+        }
+
+        firstStream.NotNull(nameof(firstStream));
+        options ??= new ReaderOptions();
+
+        var factory = FindFactory<IMultiArchiveFactory>(firstStream);
+        return await factory
+            .OpenAsync(streamsArray, options, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Extract to specific directory, retaining filename
+    /// </summary>
     public static void WriteToDirectory(
         string sourceArchive,
         string destinationDirectory,
         ExtractionOptions? options = null
     )
     {
-        using var archive = OpenArchive(sourceArchive);
+        using var archive = Open(sourceArchive);
         archive.WriteToDirectory(destinationDirectory, options);
     }
 
-    public static T FindFactory<T>(string path)
-        where T : IFactory
-    {
-        path.NotNullOrEmpty(nameof(path));
-        using Stream stream = File.OpenRead(path);
-        return FindFactory<T>(stream);
-    }
-
-    public static T FindFactory<T>(FileInfo finfo)
+    private static T FindFactory<T>(FileInfo finfo)
         where T : IFactory
     {
         finfo.NotNull(nameof(finfo));
@@ -118,7 +262,7 @@ public static partial class ArchiveFactory
         return FindFactory<T>(stream);
     }
 
-    public static T FindFactory<T>(Stream stream)
+    private static T FindFactory<T>(Stream stream)
         where T : IFactory
     {
         stream.NotNull(nameof(stream));
@@ -150,14 +294,68 @@ public static partial class ArchiveFactory
         );
     }
 
-    public static bool IsArchive(string filePath, out ArchiveType? type)
+    private static async ValueTask<T> FindFactoryAsync<T>(
+        FileInfo finfo,
+        CancellationToken cancellationToken
+    )
+        where T : IFactory
+    {
+        finfo.NotNull(nameof(finfo));
+        using Stream stream = finfo.OpenRead();
+        return await FindFactoryAsync<T>(stream, cancellationToken);
+    }
+
+    private static async ValueTask<T> FindFactoryAsync<T>(
+        Stream stream,
+        CancellationToken cancellationToken
+    )
+        where T : IFactory
+    {
+        stream.NotNull(nameof(stream));
+        if (!stream.CanRead || !stream.CanSeek)
+        {
+            throw new ArgumentException("Stream should be readable and seekable");
+        }
+
+        var factories = Factory.Factories.OfType<T>();
+
+        var startPosition = stream.Position;
+
+        foreach (var factory in factories)
+        {
+            stream.Seek(startPosition, SeekOrigin.Begin);
+
+            if (await factory.IsArchiveAsync(stream, cancellationToken: cancellationToken))
+            {
+                stream.Seek(startPosition, SeekOrigin.Begin);
+
+                return factory;
+            }
+        }
+
+        var extensions = string.Join(", ", factories.Select(item => item.Name));
+
+        throw new InvalidOperationException(
+            $"Cannot determine compressed stream type. Supported Archive Formats: {extensions}"
+        );
+    }
+
+    public static bool IsArchive(
+        string filePath,
+        out ArchiveType? type,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         filePath.NotNullOrEmpty(nameof(filePath));
         using Stream s = File.OpenRead(filePath);
-        return IsArchive(s, out type);
+        return IsArchive(s, out type, bufferSize);
     }
 
-    public static bool IsArchive(Stream stream, out ArchiveType? type)
+    public static bool IsArchive(
+        Stream stream,
+        out ArchiveType? type,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         type = null;
         stream.NotNull(nameof(stream));
@@ -184,12 +382,22 @@ public static partial class ArchiveFactory
         return false;
     }
 
+    /// <summary>
+    /// From a passed in archive (zip, rar, 7z, 001), return all parts.
+    /// </summary>
+    /// <param name="part1"></param>
+    /// <returns></returns>
     public static IEnumerable<string> GetFileParts(string part1)
     {
         part1.NotNullOrEmpty(nameof(part1));
         return GetFileParts(new FileInfo(part1)).Select(a => a.FullName);
     }
 
+    /// <summary>
+    /// From a passed in archive (zip, rar, 7z, 001), return all parts.
+    /// </summary>
+    /// <param name="part1"></param>
+    /// <returns></returns>
     public static IEnumerable<FileInfo> GetFileParts(FileInfo part1)
     {
         part1.NotNull(nameof(part1));
@@ -203,7 +411,7 @@ public static partial class ArchiveFactory
             if (part != null)
             {
                 yield return part;
-                while ((part = factory.GetFilePart(i++, part1)) != null)
+                while ((part = factory.GetFilePart(i++, part1)) != null) //tests split too
                 {
                     yield return part;
                 }
@@ -212,4 +420,6 @@ public static partial class ArchiveFactory
             }
         }
     }
+
+    public static IArchiveFactory AutoFactory { get; } = new AutoArchiveFactory();
 }

src/SharpCompress/Archives/ArchiveVolumeFactory.cs

@@ -13,7 +13,6 @@ internal abstract class ArchiveVolumeFactory
         //split 001, 002 ...
         var m = Regex.Match(part1.Name, @"^(.*\.)([0-9]+)$", RegexOptions.IgnoreCase);
         if (m.Success)
-        {
             item = new FileInfo(
                 Path.Combine(
                     part1.DirectoryName!,
@@ -23,13 +22,9 @@ internal abstract class ArchiveVolumeFactory
                     )
                 )
             );
-        }
 
         if (item != null && item.Exists)
-        {
             return item;
-        }
-
         return null;
     }
 }

src/SharpCompress/Archives/AutoArchiveFactory.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Common;
+using SharpCompress.Readers;
+
+namespace SharpCompress.Archives;
+
+internal class AutoArchiveFactory : IArchiveFactory
+{
+    public string Name => nameof(AutoArchiveFactory);
+
+    public ArchiveType? KnownArchiveType => null;
+
+    public IEnumerable<string> GetSupportedExtensions() => throw new NotSupportedException();
+
+    public bool IsArchive(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    ) => throw new NotSupportedException();
+
+    public ValueTask<bool> IsArchiveAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    ) => throw new NotSupportedException();
+
+    public FileInfo? GetFilePart(int index, FileInfo part1) => throw new NotSupportedException();
+
+    public IArchive Open(Stream stream, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.Open(stream, readerOptions);
+
+    public async ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    ) => await ArchiveFactory.OpenAsync(stream, readerOptions, cancellationToken);
+
+    public IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.Open(fileInfo, readerOptions);
+
+    public async ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    ) => await ArchiveFactory.OpenAsync(fileInfo, readerOptions, cancellationToken);
+}

src/SharpCompress/Archives/GZip/GZipArchive.Async.cs

@@ -1,86 +0,0 @@
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.GZip;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Readers.GZip;
-using SharpCompress.Writers;
-using SharpCompress.Writers.GZip;
-
-namespace SharpCompress.Archives.GZip;
-
-public partial class GZipArchive
-{
-    public ValueTask SaveToAsync(string filePath, CancellationToken cancellationToken = default) =>
-        SaveToAsync(new FileInfo(filePath), cancellationToken);
-
-    public async ValueTask SaveToAsync(
-        FileInfo fileInfo,
-        CancellationToken cancellationToken = default
-    )
-    {
-        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
-        await SaveToAsync(stream, new WriterOptions(CompressionType.GZip), cancellationToken)
-            .ConfigureAwait(false);
-    }
-
-    protected override async ValueTask SaveToAsync(
-        Stream stream,
-        WriterOptions options,
-        IAsyncEnumerable<GZipArchiveEntry> oldEntries,
-        IEnumerable<GZipArchiveEntry> newEntries,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (Entries.Count > 1)
-        {
-            throw new InvalidFormatException("Only one entry is allowed in a GZip Archive");
-        }
-        using var writer = new GZipWriter(stream, new GZipWriterOptions(options));
-        await foreach (
-            var entry in oldEntries.WithCancellation(cancellationToken).ConfigureAwait(false)
-        )
-        {
-            if (!entry.IsDirectory)
-            {
-                using var entryStream = entry.OpenEntryStream();
-                await writer
-                    .WriteAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entryStream,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-        foreach (var entry in newEntries.Where(x => !x.IsDirectory))
-        {
-            using var entryStream = entry.OpenEntryStream();
-            await writer
-                .WriteAsync(entry.Key.NotNull("Entry Key is null"), entryStream, cancellationToken)
-                .ConfigureAwait(false);
-        }
-    }
-
-    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
-    {
-        var stream = Volumes.Single().Stream;
-        stream.Position = 0;
-        return new((IAsyncReader)GZipReader.OpenReader(stream));
-    }
-
-    protected override async IAsyncEnumerable<GZipArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<GZipVolume> volumes
-    )
-    {
-        var stream = (await volumes.SingleAsync()).Stream;
-        yield return new GZipArchiveEntry(
-            this,
-            await GZipFilePart.CreateAsync(stream, ReaderOptions.ArchiveEncoding)
-        );
-    }
-}

src/SharpCompress/Archives/GZip/GZipArchive.Factory.cs

@@ -1,201 +0,0 @@
-using System;
-using System.Buffers;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.GZip;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Readers.GZip;
-using SharpCompress.Writers;
-using SharpCompress.Writers.GZip;
-
-namespace SharpCompress.Archives.GZip;
-
-public partial class GZipArchive
-#if NET8_0_OR_GREATER
-    : IWritableArchiveOpenable,
-        IMultiArchiveOpenable<IWritableArchive, IWritableAsyncArchive>
-#endif
-{
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        path.NotNullOrEmpty(nameof(path));
-        return (IWritableAsyncArchive)OpenArchive(
-            new FileInfo(path),
-            readerOptions ?? new ReaderOptions()
-        );
-    }
-
-    public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
-    {
-        filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
-    }
-
-    public static IWritableArchive OpenArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfo.NotNull(nameof(fileInfo));
-        return new GZipArchive(
-            new SourceStream(
-                fileInfo,
-                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var files = fileInfos.ToArray();
-        return new GZipArchive(
-            new SourceStream(
-                files[0],
-                i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        streams.NotNull(nameof(streams));
-        var strms = streams.ToArray();
-        return new GZipArchive(
-            new SourceStream(
-                strms[0],
-                i => i < strms.Length ? strms[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
-    {
-        stream.NotNull(nameof(stream));
-
-        if (stream is not { CanSeek: true })
-        {
-            throw new ArgumentException("Stream must be seekable", nameof(stream));
-        }
-
-        return new GZipArchive(
-            new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
-        );
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(stream, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfo, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(streams, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
-    }
-
-    public static IWritableArchive CreateArchive() => new GZipArchive();
-
-    public static IWritableAsyncArchive CreateAsyncArchive() => new GZipArchive();
-
-    public static bool IsGZipFile(string filePath) => IsGZipFile(new FileInfo(filePath));
-
-    public static bool IsGZipFile(FileInfo fileInfo)
-    {
-        if (!fileInfo.Exists)
-        {
-            return false;
-        }
-
-        using Stream stream = fileInfo.OpenRead();
-        return IsGZipFile(stream);
-    }
-
-    public static bool IsGZipFile(Stream stream)
-    {
-        Span<byte> header = stackalloc byte[10];
-
-        if (!stream.ReadFully(header))
-        {
-            return false;
-        }
-
-        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-        {
-            return false;
-        }
-
-        return true;
-    }
-
-    public static async ValueTask<bool> IsGZipFileAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var header = ArrayPool<byte>.Shared.Rent(10);
-        try
-        {
-            await stream.ReadFullyAsync(header, 0, 10, cancellationToken).ConfigureAwait(false);
-
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                return false;
-            }
-
-            return true;
-        }
-        finally
-        {
-            ArrayPool<byte>.Shared.Return(header);
-        }
-    }
-}

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -14,20 +14,186 @@ using SharpCompress.Writers.GZip;
 
 namespace SharpCompress.Archives.GZip;
 
-public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
+public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
 {
+    /// <summary>
+    /// Constructor expects a filepath to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="readerOptions"></param>
+    public static GZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
+    }
+
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    public static GZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+    {
+        fileInfo.NotNull(nameof(fileInfo));
+        return new GZipArchive(
+            new SourceStream(
+                fileInfo,
+                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all file parts passed in
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    public static GZipArchive Open(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var files = fileInfos.ToArray();
+        return new GZipArchive(
+            new SourceStream(
+                files[0],
+                i => i < files.Length ? files[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all stream parts passed in
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    public static GZipArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
+    {
+        streams.NotNull(nameof(streams));
+        var strms = streams.ToArray();
+        return new GZipArchive(
+            new SourceStream(
+                strms[0],
+                i => i < strms.Length ? strms[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Takes a seekable Stream as a source
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    public static GZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+    {
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
+        return new GZipArchive(
+            new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
+        );
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(stream, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfo, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(streams, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfos, readerOptions));
+    }
+
+    public static GZipArchive Create() => new();
+
+    /// <summary>
+    /// Constructor with a SourceStream able to handle FileInfo and Streams.
+    /// </summary>
+    /// <param name="sourceStream"></param>
     private GZipArchive(SourceStream sourceStream)
         : base(ArchiveType.GZip, sourceStream) { }
 
-    internal GZipArchive()
-        : base(ArchiveType.GZip) { }
-
     protected override IEnumerable<GZipVolume> LoadVolumes(SourceStream sourceStream)
     {
         sourceStream.LoadAllParts();
         return sourceStream.Streams.Select(a => new GZipVolume(a, ReaderOptions, 0));
     }
 
+    public static bool IsGZipFile(string filePath) => IsGZipFile(new FileInfo(filePath));
+
+    public static bool IsGZipFile(FileInfo fileInfo)
+    {
+        if (!fileInfo.Exists)
+        {
+            return false;
+        }
+
+        using Stream stream = fileInfo.OpenRead();
+        return IsGZipFile(stream);
+    }
+
     public void SaveTo(string filePath) => SaveTo(new FileInfo(filePath));
 
     public void SaveTo(FileInfo fileInfo)
@@ -36,6 +202,63 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         SaveTo(stream, new WriterOptions(CompressionType.GZip));
     }
 
+    public ValueTask SaveToAsync(string filePath, CancellationToken cancellationToken = default) =>
+        SaveToAsync(new FileInfo(filePath), cancellationToken);
+
+    public async ValueTask SaveToAsync(
+        FileInfo fileInfo,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        await SaveToAsync(stream, new WriterOptions(CompressionType.GZip), cancellationToken)
+            .ConfigureAwait(false);
+    }
+
+    public static bool IsGZipFile(Stream stream)
+    {
+        // read the header on the first read
+        Span<byte> header = stackalloc byte[10];
+
+        // workitem 8501: handle edge case (decompress empty stream)
+        if (!stream.ReadFully(header))
+        {
+            return false;
+        }
+
+        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    public static async ValueTask<bool> IsGZipFileAsync(
+        Stream stream,
+        CancellationToken cancellationToken = default
+    )
+    {
+        // read the header on the first read
+        byte[] header = new byte[10];
+
+        // workitem 8501: handle edge case (decompress empty stream)
+        if (!await stream.ReadFullyAsync(header, cancellationToken).ConfigureAwait(false))
+        {
+            return false;
+        }
+
+        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    internal GZipArchive()
+        : base(ArchiveType.GZip) { }
+
     protected override GZipArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -79,12 +302,34 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<GZipArchiveEntry> oldEntries,
+        IEnumerable<GZipArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        if (Entries.Count > 1)
+        {
+            throw new InvalidFormatException("Only one entry is allowed in a GZip Archive");
+        }
+        using var writer = new GZipWriter(stream, new GZipWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries).Where(x => !x.IsDirectory))
+        {
+            using var entryStream = entry.OpenEntryStream();
+            await writer
+                .WriteAsync(entry.Key.NotNull("Entry Key is null"), entryStream, cancellationToken)
+                .ConfigureAwait(false);
+        }
+    }
+
     protected override IEnumerable<GZipArchiveEntry> LoadEntries(IEnumerable<GZipVolume> volumes)
     {
         var stream = volumes.Single().Stream;
         yield return new GZipArchiveEntry(
             this,
-            GZipFilePart.Create(stream, ReaderOptions.ArchiveEncoding)
+            new GZipFilePart(stream, ReaderOptions.ArchiveEncoding)
         );
     }
 
@@ -92,6 +337,13 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
-        return GZipReader.OpenReader(stream);
+        return GZipReader.Open(stream);
+    }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new(GZipReader.Open(stream));
     }
 }

src/SharpCompress/Archives/GZip/GZipArchiveEntry.cs

@@ -23,10 +23,12 @@ public class GZipArchiveEntry : GZipEntry, IArchiveEntry
         return Parts.Single().GetCompressedStream().NotNull();
     }
 
-    public ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
+    public async ValueTask<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    )
     {
         // GZip synchronous implementation is fast enough, just wrap it
-        return new(OpenEntryStream());
+        return OpenEntryStream();
     }
 
     #region IArchiveEntry Members

src/SharpCompress/Archives/IArchive.cs

@@ -38,10 +38,5 @@ public interface IArchive : IDisposable
     /// <summary>
     /// The total size of the files as uncompressed in the archive.
     /// </summary>
-    long TotalUncompressedSize { get; }
-
-    /// <summary>
-    /// Returns whether the archive is encrypted.
-    /// </summary>
-    bool IsEncrypted { get; }
+    long TotalUncompressSize { get; }
 }

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -9,6 +9,8 @@ namespace SharpCompress.Archives;
 
 public static class IArchiveEntryExtensions
 {
+    private const int BufferSize = 81920;
+
     /// <param name="archiveEntry">The archive entry to extract.</param>
     extension(IArchiveEntry archiveEntry)
     {
@@ -26,7 +28,7 @@ public static class IArchiveEntryExtensions
 
             using var entryStream = archiveEntry.OpenEntryStream();
             var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
-            sourceStream.CopyTo(streamToWriteTo, Constants.BufferSize);
+            sourceStream.CopyTo(streamToWriteTo, BufferSize);
         }
 
         /// <summary>
@@ -49,7 +51,7 @@ public static class IArchiveEntryExtensions
             using var entryStream = await archiveEntry.OpenEntryStreamAsync(cancellationToken);
             var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
             await sourceStream
-                .CopyToAsync(streamToWriteTo, Constants.BufferSize, cancellationToken)
+                .CopyToAsync(streamToWriteTo, BufferSize, cancellationToken)
                 .ConfigureAwait(false);
         }
     }

src/SharpCompress/Archives/IArchiveExtensions.cs

@@ -8,6 +8,7 @@ namespace SharpCompress.Archives;
 
 public static class IArchiveExtensions
 {
+    /// <param name="archive">The archive to extract.</param>
     extension(IArchive archive)
     {
         /// <summary>
@@ -22,6 +23,7 @@ public static class IArchiveExtensions
             IProgress<ProgressReport>? progress = null
         )
         {
+            // For solid archives (Rar, 7Zip), use the optimized reader-based approach
             if (archive.IsSolid || archive.Type == ArchiveType.SevenZip)
             {
                 using var reader = archive.ExtractAllEntries();
@@ -29,6 +31,7 @@ public static class IArchiveExtensions
             }
             else
             {
+                // For non-solid archives, extract entries directly
                 archive.WriteToDirectoryInternal(destinationDirectory, options, progress);
             }
         }
@@ -39,10 +42,14 @@ public static class IArchiveExtensions
             IProgress<ProgressReport>? progress
         )
         {
-            var totalBytes = archive.TotalUncompressedSize;
+            // Prepare for progress reporting
+            var totalBytes = archive.TotalUncompressSize;
             var bytesRead = 0L;
+
+            // Tracking for created directories.
             var seenDirectories = new HashSet<string>();
 
+            // Extract
             foreach (var entry in archive.Entries)
             {
                 if (entry.IsDirectory)
@@ -61,8 +68,10 @@ public static class IArchiveExtensions
                     continue;
                 }
 
+                // Use the entry's WriteToDirectory method which respects ExtractionOptions
                 entry.WriteToDirectory(destinationDirectory, options);
 
+                // Update progress
                 bytesRead += entry.Size;
                 progress?.Report(
                     new ProgressReport(entry.Key ?? string.Empty, bytesRead, totalBytes)

src/SharpCompress/Archives/IArchiveFactory.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Factories;
 using SharpCompress.Readers;
 
@@ -25,21 +26,26 @@ public interface IArchiveFactory : IFactory
     /// </summary>
     /// <param name="stream">An open, readable and seekable stream.</param>
     /// <param name="readerOptions">reading options.</param>
-    IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null);
+    IArchive Open(Stream stream, ReaderOptions? readerOptions = null);
 
     /// <summary>
     /// Opens an Archive for random access asynchronously.
     /// </summary>
     /// <param name="stream">An open, readable and seekable stream.</param>
     /// <param name="readerOptions">reading options.</param>
-    IAsyncArchive OpenAsyncArchive(Stream stream, ReaderOptions? readerOptions = null);
+    /// <param name="cancellationToken">Cancellation token.</param>
+    ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 
     /// <summary>
     /// Constructor with a FileInfo object to an existing file.
     /// </summary>
     /// <param name="fileInfo">the file to open.</param>
     /// <param name="readerOptions">reading options.</param>
-    IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null);
+    IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null);
 
     /// <summary>
     /// Opens an Archive from a FileInfo object asynchronously.
@@ -47,5 +53,9 @@ public interface IArchiveFactory : IFactory
     /// <param name="fileInfo">the file to open.</param>
     /// <param name="readerOptions">reading options.</param>
     /// <param name="cancellationToken">Cancellation token.</param>
-    IAsyncArchive OpenAsyncArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null);
+    ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 }

src/SharpCompress/Archives/IArchiveOpenable.cs

@@ -1,40 +0,0 @@
-#if NET8_0_OR_GREATER
-using System.IO;
-using System.Threading;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives;
-
-public interface IArchiveOpenable<TSync, TASync>
-    where TSync : IArchive
-    where TASync : IAsyncArchive
-{
-    public static abstract TSync OpenArchive(string filePath, ReaderOptions? readerOptions = null);
-
-    public static abstract TSync OpenArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null
-    );
-
-    public static abstract TSync OpenArchive(Stream stream, ReaderOptions? readerOptions = null);
-
-    public static abstract TASync OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    );
-
-    public static abstract TASync OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    );
-
-    public static abstract TASync OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    );
-}
-
-#endif

src/SharpCompress/Archives/IAsyncArchive.cs

@@ -39,10 +39,5 @@ public interface IAsyncArchive : IAsyncDisposable
     /// <summary>
     /// The total size of the files as uncompressed in the archive.
     /// </summary>
-    ValueTask<long> TotalUncompressedSizeAsync();
-
-    /// <summary>
-    /// Returns whether the archive is encrypted.
-    /// </summary>
-    ValueTask<bool> IsEncryptedAsync();
+    ValueTask<long> TotalUncompressSizeAsync();
 }

src/SharpCompress/Archives/IAsyncArchiveExtensions.cs

@@ -10,83 +10,84 @@ namespace SharpCompress.Archives;
 
 public static class IAsyncArchiveExtensions
 {
-    extension(IAsyncArchive archive)
+    /// <summary>
+    /// Extract to specific directory asynchronously with progress reporting and cancellation support
+    /// </summary>
+    /// <param name="archive">The archive to extract.</param>
+    /// <param name="destinationDirectory">The folder to extract into.</param>
+    /// <param name="options">Extraction options.</param>
+    /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
+    /// <param name="cancellationToken">Optional cancellation token.</param>
+    public static async Task WriteToDirectoryAsync(
+        this IAsyncArchive archive,
+        string destinationDirectory,
+        ExtractionOptions? options = null,
+        IProgress<ProgressReport>? progress = null,
+        CancellationToken cancellationToken = default
+    )
     {
-        /// <summary>
-        /// Extract to specific directory asynchronously with progress reporting and cancellation support
-        /// </summary>
-        /// <param name="archive">The archive to extract.</param>
-        /// <param name="destinationDirectory">The folder to extract into.</param>
-        /// <param name="options">Extraction options.</param>
-        /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
-        /// <param name="cancellationToken">Optional cancellation token.</param>
-        public async ValueTask WriteToDirectoryAsync(
-            string destinationDirectory,
-            ExtractionOptions? options = null,
-            IProgress<ProgressReport>? progress = null,
-            CancellationToken cancellationToken = default
-        )
+        // For solid archives (Rar, 7Zip), use the optimized reader-based approach
+        if (await archive.IsSolidAsync() || archive.Type == ArchiveType.SevenZip)
         {
-            if (await archive.IsSolidAsync() || archive.Type == ArchiveType.SevenZip)
-            {
-                await using var reader = await archive.ExtractAllEntriesAsync();
-                await reader.WriteAllToDirectoryAsync(
-                    destinationDirectory,
-                    options,
-                    cancellationToken
-                );
-            }
-            else
-            {
-                await archive.WriteToDirectoryAsyncInternal(
-                    destinationDirectory,
-                    options,
-                    progress,
-                    cancellationToken
-                );
-            }
+            await using var reader = await archive.ExtractAllEntriesAsync();
+            await reader.WriteAllToDirectoryAsync(destinationDirectory, options, cancellationToken);
         }
-
-        private async ValueTask WriteToDirectoryAsyncInternal(
-            string destinationDirectory,
-            ExtractionOptions? options,
-            IProgress<ProgressReport>? progress,
-            CancellationToken cancellationToken
-        )
+        else
         {
-            var totalBytes = await archive.TotalUncompressedSizeAsync();
-            var bytesRead = 0L;
-            var seenDirectories = new HashSet<string>();
+            // For non-solid archives, extract entries directly
+            await archive.WriteToDirectoryAsyncInternal(
+                destinationDirectory,
+                options,
+                progress,
+                cancellationToken
+            );
+        }
+    }
 
-            await foreach (var entry in archive.EntriesAsync.WithCancellation(cancellationToken))
+    private static async Task WriteToDirectoryAsyncInternal(
+        this IAsyncArchive archive,
+        string destinationDirectory,
+        ExtractionOptions? options,
+        IProgress<ProgressReport>? progress,
+        CancellationToken cancellationToken
+    )
+    {
+        // Prepare for progress reporting
+        var totalBytes = await archive.TotalUncompressSizeAsync();
+        var bytesRead = 0L;
+
+        // Tracking for created directories.
+        var seenDirectories = new HashSet<string>();
+
+        // Extract
+        await foreach (var entry in archive.EntriesAsync.WithCancellation(cancellationToken))
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            if (entry.IsDirectory)
             {
-                cancellationToken.ThrowIfCancellationRequested();
-
-                if (entry.IsDirectory)
-                {
-                    var dirPath = Path.Combine(
-                        destinationDirectory,
-                        entry.Key.NotNull("Entry Key is null")
-                    );
-                    if (
-                        Path.GetDirectoryName(dirPath + "/") is { } parentDirectory
-                        && seenDirectories.Add(dirPath)
-                    )
-                    {
-                        Directory.CreateDirectory(parentDirectory);
-                    }
-                    continue;
-                }
-
-                await entry
-                    .WriteToDirectoryAsync(destinationDirectory, options, cancellationToken)
-                    .ConfigureAwait(false);
-
-                bytesRead += entry.Size;
-                progress?.Report(
-                    new ProgressReport(entry.Key ?? string.Empty, bytesRead, totalBytes)
+                var dirPath = Path.Combine(
+                    destinationDirectory,
+                    entry.Key.NotNull("Entry Key is null")
                 );
+                if (
+                    Path.GetDirectoryName(dirPath + "/") is { } parentDirectory
+                    && seenDirectories.Add(dirPath)
+                )
+                {
+                    Directory.CreateDirectory(parentDirectory);
+                }
+                continue;
             }
+
+            // Use the entry's WriteToDirectoryAsync method which respects ExtractionOptions
+            await entry
+                .WriteToDirectoryAsync(destinationDirectory, options, cancellationToken)
+                .ConfigureAwait(false);
+
+            // Update progress
+            bytesRead += entry.Size;
+            progress?.Report(new ProgressReport(entry.Key ?? string.Empty, bytesRead, totalBytes));
         }
     }
 }

src/SharpCompress/Archives/IMultiArchiveFactory.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Factories;
 using SharpCompress.Readers;
 
@@ -26,16 +27,18 @@ public interface IMultiArchiveFactory : IFactory
     /// </summary>
     /// <param name="streams"></param>
     /// <param name="readerOptions">reading options.</param>
-    IArchive OpenArchive(IReadOnlyList<Stream> streams, ReaderOptions? readerOptions = null);
+    IArchive Open(IReadOnlyList<Stream> streams, ReaderOptions? readerOptions = null);
 
     /// <summary>
     /// Opens a multi-part archive from streams asynchronously.
     /// </summary>
     /// <param name="streams"></param>
     /// <param name="readerOptions">reading options.</param>
-    IAsyncArchive OpenAsyncArchive(
+    /// <param name="cancellationToken">Cancellation token.</param>
+    ValueTask<IAsyncArchive> OpenAsync(
         IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
     );
 
     /// <summary>
@@ -43,7 +46,7 @@ public interface IMultiArchiveFactory : IFactory
     /// </summary>
     /// <param name="fileInfos"></param>
     /// <param name="readerOptions">reading options.</param>
-    IArchive OpenArchive(IReadOnlyList<FileInfo> fileInfos, ReaderOptions? readerOptions = null);
+    IArchive Open(IReadOnlyList<FileInfo> fileInfos, ReaderOptions? readerOptions = null);
 
     /// <summary>
     /// Opens a multi-part archive from files asynchronously.
@@ -51,7 +54,7 @@ public interface IMultiArchiveFactory : IFactory
     /// <param name="fileInfos"></param>
     /// <param name="readerOptions">reading options.</param>
     /// <param name="cancellationToken">Cancellation token.</param>
-    IAsyncArchive OpenAsyncArchive(
+    ValueTask<IAsyncArchive> OpenAsync(
         IReadOnlyList<FileInfo> fileInfos,
         ReaderOptions? readerOptions = null,
         CancellationToken cancellationToken = default

src/SharpCompress/Archives/IMultiArchiveOpenable.cs

@@ -1,35 +0,0 @@
-#if NET8_0_OR_GREATER
-using System.Collections.Generic;
-using System.IO;
-using System.Threading;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives;
-
-public interface IMultiArchiveOpenable<TSync, TASync>
-    where TSync : IArchive
-    where TASync : IAsyncArchive
-{
-    public static abstract TSync OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    );
-
-    public static abstract TSync OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    );
-
-    public static abstract TASync OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    );
-
-    public static abstract TASync OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    );
-}
-#endif

src/SharpCompress/Archives/IWritableArchive.cs

@@ -6,17 +6,10 @@ using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
 
-public interface IWritableArchiveCommon
+public interface IWritableArchive : IArchive
 {
-    /// <summary>
-    /// Use this to pause entry rebuilding when adding large collections of entries.  Dispose when complete.  A  using statement is recommended.
-    /// </summary>
-    /// <returns>IDisposeable to resume entry rebuilding</returns>
-    IDisposable PauseEntryRebuilding();
-}
+    void RemoveEntry(IArchiveEntry entry);
 
-public interface IWritableArchive : IArchive, IWritableArchiveCommon
-{
     IArchiveEntry AddEntry(
         string key,
         Stream source,
@@ -27,22 +20,8 @@ public interface IWritableArchive : IArchive, IWritableArchiveCommon
 
     IArchiveEntry AddDirectoryEntry(string key, DateTime? modified = null);
 
-    /// <summary>
-    /// Saves the archive to the specified stream using the given writer options.
-    /// </summary>
     void SaveTo(Stream stream, WriterOptions options);
 
-    /// <summary>
-    /// Removes the specified entry from the archive.
-    /// </summary>
-    void RemoveEntry(IArchiveEntry entry);
-}
-
-public interface IWritableAsyncArchive : IAsyncArchive, IWritableArchiveCommon
-{
-    /// <summary>
-    /// Asynchronously saves the archive to the specified stream using the given writer options.
-    /// </summary>
     ValueTask SaveToAsync(
         Stream stream,
         WriterOptions options,
@@ -50,28 +29,8 @@ public interface IWritableAsyncArchive : IAsyncArchive, IWritableArchiveCommon
     );
 
     /// <summary>
-    /// Asynchronously adds an entry to the archive with the specified key, source stream, and options.
+    /// Use this to pause entry rebuilding when adding large collections of entries.  Dispose when complete.  A  using statement is recommended.
     /// </summary>
-    ValueTask<IArchiveEntry> AddEntryAsync(
-        string key,
-        Stream source,
-        bool closeStream,
-        long size = 0,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    );
-
-    /// <summary>
-    /// Asynchronously adds a directory entry to the archive with the specified key and modification time.
-    /// </summary>
-    ValueTask<IArchiveEntry> AddDirectoryEntryAsync(
-        string key,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    );
-
-    /// <summary>
-    /// Removes the specified entry from the archive.
-    /// </summary>
-    ValueTask RemoveEntryAsync(IArchiveEntry entry);
+    /// <returns>IDisposeable to resume entry rebuilding</returns>
+    IDisposable PauseEntryRebuilding();
 }

src/SharpCompress/Archives/IWritableArchiveExtensions.cs

@@ -1,70 +1,106 @@
-using System;
+using System;
 using System.IO;
-using SharpCompress.Common;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
 
 public static class IWritableArchiveExtensions
 {
-    extension(IWritableArchive writableArchive)
+    public static void AddEntry(
+        this IWritableArchive writableArchive,
+        string entryPath,
+        string filePath
+    )
     {
-        public void AddAllFromDirectory(
-            string filePath,
-            string searchPattern = "*.*",
-            SearchOption searchOption = SearchOption.AllDirectories
-        )
+        var fileInfo = new FileInfo(filePath);
+        if (!fileInfo.Exists)
         {
-            using (writableArchive.PauseEntryRebuilding())
-            {
-                foreach (
-                    var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption)
-                )
-                {
-                    var fileInfo = new FileInfo(path);
-                    writableArchive.AddEntry(
-                        path.Substring(filePath.Length),
-                        fileInfo.OpenRead(),
-                        true,
-                        fileInfo.Length,
-                        fileInfo.LastWriteTime
-                    );
-                }
-            }
+            throw new FileNotFoundException("Could not AddEntry: " + filePath);
         }
+        writableArchive.AddEntry(
+            entryPath,
+            new FileInfo(filePath).OpenRead(),
+            true,
+            fileInfo.Length,
+            fileInfo.LastWriteTime
+        );
+    }
 
-        public IArchiveEntry AddEntry(string key, string file) =>
-            writableArchive.AddEntry(key, new FileInfo(file));
+    public static void SaveTo(
+        this IWritableArchive writableArchive,
+        string filePath,
+        WriterOptions options
+    ) => writableArchive.SaveTo(new FileInfo(filePath), options);
 
-        public IArchiveEntry AddEntry(
-            string key,
-            Stream source,
-            long size = 0,
-            DateTime? modified = null
-        ) => writableArchive.AddEntry(key, source, false, size, modified);
+    public static void SaveTo(
+        this IWritableArchive writableArchive,
+        FileInfo fileInfo,
+        WriterOptions options
+    )
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        writableArchive.SaveTo(stream, options);
+    }
 
-        public IArchiveEntry AddEntry(string key, FileInfo fileInfo)
+    public static ValueTask SaveToAsync(
+        this IWritableArchive writableArchive,
+        string filePath,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    ) => writableArchive.SaveToAsync(new FileInfo(filePath), options, cancellationToken);
+
+    public static async ValueTask SaveToAsync(
+        this IWritableArchive writableArchive,
+        FileInfo fileInfo,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        await writableArchive.SaveToAsync(stream, options, cancellationToken).ConfigureAwait(false);
+    }
+
+    public static void AddAllFromDirectory(
+        this IWritableArchive writableArchive,
+        string filePath,
+        string searchPattern = "*.*",
+        SearchOption searchOption = SearchOption.AllDirectories
+    )
+    {
+        using (writableArchive.PauseEntryRebuilding())
         {
-            if (!fileInfo.Exists)
+            foreach (var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption))
             {
-                throw new ArgumentException("FileInfo does not exist.");
+                var fileInfo = new FileInfo(path);
+                writableArchive.AddEntry(
+                    path.Substring(filePath.Length),
+                    fileInfo.OpenRead(),
+                    true,
+                    fileInfo.Length,
+                    fileInfo.LastWriteTime
+                );
             }
-            return writableArchive.AddEntry(
-                key,
-                fileInfo.OpenRead(),
-                true,
-                fileInfo.Length,
-                fileInfo.LastWriteTime
-            );
-        }
-
-        public void SaveTo(string filePath, WriterOptions? options = null) =>
-            writableArchive.SaveTo(new FileInfo(filePath), options ?? new(CompressionType.Deflate));
-
-        public void SaveTo(FileInfo fileInfo, WriterOptions? options = null)
-        {
-            using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
-            writableArchive.SaveTo(stream, options ?? new(CompressionType.Deflate));
         }
     }
+
+    public static IArchiveEntry AddEntry(
+        this IWritableArchive writableArchive,
+        string key,
+        FileInfo fileInfo
+    )
+    {
+        if (!fileInfo.Exists)
+        {
+            throw new ArgumentException("FileInfo does not exist.");
+        }
+        return writableArchive.AddEntry(
+            key,
+            fileInfo.OpenRead(),
+            true,
+            fileInfo.Length,
+            fileInfo.LastWriteTime
+        );
+    }
 }

src/SharpCompress/Archives/IWritableArchiveOpenable.cs

@@ -1,10 +0,0 @@
-#if NET8_0_OR_GREATER
-namespace SharpCompress.Archives;
-
-public interface IWritableArchiveOpenable
-    : IArchiveOpenable<IWritableArchive, IWritableAsyncArchive>
-{
-    public static abstract IWritableArchive CreateArchive();
-    public static abstract IWritableAsyncArchive CreateAsyncArchive();
-}
-#endif

src/SharpCompress/Archives/IWritableAsyncArchiveExtensions.cs

@@ -1,86 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Writers;
-
-namespace SharpCompress.Archives;
-
-public static class IWritableAsyncArchiveExtensions
-{
-    extension(IWritableAsyncArchive writableArchive)
-    {
-        public async ValueTask AddAllFromDirectoryAsync(
-            string filePath,
-            string searchPattern = "*.*",
-            SearchOption searchOption = SearchOption.AllDirectories
-        )
-        {
-            using (writableArchive.PauseEntryRebuilding())
-            {
-                foreach (
-                    var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption)
-                )
-                {
-                    var fileInfo = new FileInfo(path);
-                    await writableArchive.AddEntryAsync(
-                        path.Substring(filePath.Length),
-                        fileInfo.OpenRead(),
-                        true,
-                        fileInfo.Length,
-                        fileInfo.LastWriteTime
-                    );
-                }
-            }
-        }
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(string key, string file) =>
-            writableArchive.AddEntryAsync(key, new FileInfo(file));
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(
-            string key,
-            Stream source,
-            long size = 0,
-            DateTime? modified = null
-        ) => writableArchive.AddEntryAsync(key, source, false, size, modified);
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(string key, FileInfo fileInfo)
-        {
-            if (!fileInfo.Exists)
-            {
-                throw new ArgumentException("FileInfo does not exist.");
-            }
-            return writableArchive.AddEntryAsync(
-                key,
-                fileInfo.OpenRead(),
-                true,
-                fileInfo.Length,
-                fileInfo.LastWriteTime
-            );
-        }
-
-        public ValueTask SaveToAsync(
-            string filePath,
-            WriterOptions? options = null,
-            CancellationToken cancellationToken = default
-        ) =>
-            writableArchive.SaveToAsync(
-                new FileInfo(filePath),
-                options ?? new(CompressionType.Deflate),
-                cancellationToken
-            );
-
-        public async ValueTask SaveToAsync(
-            FileInfo fileInfo,
-            WriterOptions? options = null,
-            CancellationToken cancellationToken = default
-        )
-        {
-            using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
-            await writableArchive
-                .SaveToAsync(stream, options ?? new(CompressionType.Deflate), cancellationToken)
-                .ConfigureAwait(false);
-        }
-    }
-}

src/SharpCompress/Archives/IWriteableArchiveFactory.cs

@@ -16,5 +16,5 @@ public interface IWriteableArchiveFactory : Factories.IFactory
     /// Creates a new, empty archive, ready to be written.
     /// </summary>
     /// <returns></returns>
-    IWritableArchive CreateArchive();
+    IWritableArchive CreateWriteableArchive();
 }

src/SharpCompress/Archives/Rar/FileInfoRarArchiveVolume.cs

@@ -36,7 +36,4 @@ internal class FileInfoRarArchiveVolume : RarVolume
         new FileInfoRarFilePart(this, ReaderOptions.Password, markHeader, fileHeader, FileInfo);
 
     internal override IEnumerable<RarFilePart> ReadFileParts() => FileParts;
-
-    internal override IAsyncEnumerable<RarFilePart> ReadFilePartsAsync() =>
-        FileParts.ToAsyncEnumerable();
 }

src/SharpCompress/Archives/Rar/RarArchive.Async.cs

@@ -1,53 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Archives.Rar;
-using SharpCompress.Common;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Readers.Rar;
-
-namespace SharpCompress.Archives.Rar;
-
-public partial class RarArchive
-{
-    public override async ValueTask DisposeAsync()
-    {
-        if (!_disposed)
-        {
-            if (UnpackV1.IsValueCreated && UnpackV1.Value is IDisposable unpackV1)
-            {
-                unpackV1.Dispose();
-            }
-
-            _disposed = true;
-            await base.DisposeAsync();
-        }
-    }
-
-    protected override async ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
-    {
-        if (await this.IsMultipartVolumeAsync())
-        {
-            var streams = await VolumesAsync
-                .Select(volume =>
-                {
-                    volume.Stream.Position = 0;
-                    return volume.Stream;
-                })
-                .ToListAsync();
-            return (RarReader)RarReader.OpenReader(streams, ReaderOptions);
-        }
-
-        var stream = (await VolumesAsync.FirstAsync()).Stream;
-        stream.Position = 0;
-        return (RarReader)RarReader.OpenReader(stream, ReaderOptions);
-    }
-
-    public override async ValueTask<bool> IsSolidAsync() =>
-        await (await VolumesAsync.CastAsync<RarVolume>().FirstAsync()).IsSolidArchiveAsync();
-}

src/SharpCompress/Archives/Rar/RarArchive.Extensions.cs

@@ -1,36 +1,18 @@
-using System.Linq;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
+using System.Linq;
 
 namespace SharpCompress.Archives.Rar;
 
 public static class RarArchiveExtensions
 {
-    extension(IRarArchive archive)
-    {
-        /// <summary>
-        /// RarArchive is the first volume of a multi-part archive.  If MultipartVolume is true and IsFirstVolume is false then the first volume file must be missing.
-        /// </summary>
-        public bool IsFirstVolume() => archive.Volumes.Cast<RarVolume>().First().IsFirstVolume;
+    /// <summary>
+    /// RarArchive is the first volume of a multi-part archive.  If MultipartVolume is true and IsFirstVolume is false then the first volume file must be missing.
+    /// </summary>
+    public static bool IsFirstVolume(this RarArchive archive) =>
+        archive.Volumes.First().IsFirstVolume;
 
-        /// <summary>
-        /// RarArchive is part of a multi-part archive.
-        /// </summary>
-        public bool IsMultipartVolume() => archive.Volumes.Cast<RarVolume>().First().IsMultiVolume;
-    }
-
-    extension(IRarAsyncArchive archive)
-    {
-        /// <summary>
-        /// RarArchive is the first volume of a multi-part archive.  If MultipartVolume is true and IsFirstVolume is false then the first volume file must be missing.
-        /// </summary>
-        public async ValueTask<bool> IsFirstVolumeAsync() =>
-            (await archive.VolumesAsync.CastAsync<RarVolume>().FirstAsync()).IsFirstVolume;
-
-        /// <summary>
-        /// RarArchive is part of a multi-part archive.
-        /// </summary>
-        public async ValueTask<bool> IsMultipartVolumeAsync() =>
-            (await archive.VolumesAsync.CastAsync<RarVolume>().FirstAsync()).IsMultiVolume;
-    }
+    /// <summary>
+    /// RarArchive is part of a multi-part archive.
+    /// </summary>
+    public static bool IsMultipartVolume(this RarArchive archive) =>
+        archive.Volumes.First().IsMultiVolume;
 }

src/SharpCompress/Archives/Rar/RarArchive.Factory.cs

@@ -1,187 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Rar;
-using SharpCompress.Common.Rar.Headers;
-using SharpCompress.Compressors.Rar;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Readers.Rar;
-
-namespace SharpCompress.Archives.Rar;
-
-public partial class RarArchive
-#if NET8_0_OR_GREATER
-    : IArchiveOpenable<IRarArchive, IRarAsyncArchive>,
-        IMultiArchiveOpenable<IRarArchive, IRarAsyncArchive>
-#endif
-{
-    public static IRarAsyncArchive OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        path.NotNullOrEmpty(nameof(path));
-        return (IRarAsyncArchive)OpenArchive(new FileInfo(path), readerOptions);
-    }
-
-    public static IRarArchive OpenArchive(string filePath, ReaderOptions? options = null)
-    {
-        filePath.NotNullOrEmpty(nameof(filePath));
-        var fileInfo = new FileInfo(filePath);
-        return new RarArchive(
-            new SourceStream(
-                fileInfo,
-                i => RarArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                options ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IRarArchive OpenArchive(FileInfo fileInfo, ReaderOptions? options = null)
-    {
-        fileInfo.NotNull(nameof(fileInfo));
-        return new RarArchive(
-            new SourceStream(
-                fileInfo,
-                i => RarArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                options ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IRarArchive OpenArchive(Stream stream, ReaderOptions? options = null)
-    {
-        stream.NotNull(nameof(stream));
-
-        if (stream is not { CanSeek: true })
-        {
-            throw new ArgumentException("Stream must be seekable", nameof(stream));
-        }
-
-        return new RarArchive(new SourceStream(stream, _ => null, options ?? new ReaderOptions()));
-    }
-
-    public static IRarArchive OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var files = fileInfos.ToArray();
-        return new RarArchive(
-            new SourceStream(
-                files[0],
-                i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IRarArchive OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        streams.NotNull(nameof(streams));
-        var strms = streams.ToArray();
-        return new RarArchive(
-            new SourceStream(
-                strms[0],
-                i => i < strms.Length ? strms[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IRarAsyncArchive OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IRarAsyncArchive)OpenArchive(stream, readerOptions);
-    }
-
-    public static IRarAsyncArchive OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IRarAsyncArchive)OpenArchive(fileInfo, readerOptions);
-    }
-
-    public static IRarAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IRarAsyncArchive)OpenArchive(streams, readerOptions);
-    }
-
-    public static IRarAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IRarAsyncArchive)OpenArchive(fileInfos, readerOptions);
-    }
-
-    public static bool IsRarFile(string filePath) => IsRarFile(new FileInfo(filePath));
-
-    public static bool IsRarFile(FileInfo fileInfo)
-    {
-        if (!fileInfo.Exists)
-        {
-            return false;
-        }
-        using Stream stream = fileInfo.OpenRead();
-        return IsRarFile(stream);
-    }
-
-    public static bool IsRarFile(Stream stream, ReaderOptions? options = null)
-    {
-        try
-        {
-            MarkHeader.Read(stream, true, false);
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static async ValueTask<bool> IsRarFileAsync(
-        Stream stream,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        try
-        {
-            await MarkHeader
-                .ReadAsync(stream, true, false, cancellationToken)
-                .ConfigureAwait(false);
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-}

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -14,26 +14,17 @@ using SharpCompress.Readers.Rar;
 
 namespace SharpCompress.Archives.Rar;
 
-public interface IRarArchiveCommon
-{
-    int MinVersion { get; }
-    int MaxVersion { get; }
-}
-
-public interface IRarArchive : IArchive, IRarArchiveCommon { }
-
-public interface IRarAsyncArchive : IAsyncArchive, IRarArchiveCommon { }
-
-public partial class RarArchive
-    : AbstractArchive<RarArchiveEntry, RarVolume>,
-        IRarArchive,
-        IRarAsyncArchive
+public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
 {
     private bool _disposed;
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
         new(() => new Compressors.Rar.UnpackV2017.Unpack());
     internal Lazy<IRarUnpack> UnpackV1 { get; } = new(() => new Compressors.Rar.UnpackV1.Unpack());
 
+    /// <summary>
+    /// Constructor with a SourceStream able to handle FileInfo and Streams.
+    /// </summary>
+    /// <param name="sourceStream"></param>
     private RarArchive(SourceStream sourceStream)
         : base(ArchiveType.Rar, sourceStream) { }
 
@@ -54,17 +45,12 @@ public partial class RarArchive
     protected override IEnumerable<RarArchiveEntry> LoadEntries(IEnumerable<RarVolume> volumes) =>
         RarArchiveEntryFactory.GetEntries(this, volumes, ReaderOptions);
 
-    // Simple async property - kept in original file
-    protected override IAsyncEnumerable<RarArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<RarVolume> volumes
-    ) => RarArchiveEntryFactory.GetEntriesAsync(this, volumes, ReaderOptions);
-
     protected override IEnumerable<RarVolume> LoadVolumes(SourceStream sourceStream)
     {
-        sourceStream.LoadAllParts();
+        sourceStream.LoadAllParts(); //request all streams
         var streams = sourceStream.Streams.ToArray();
         var i = 0;
-        if (streams.Length > 1 && IsRarFile(streams[1], ReaderOptions))
+        if (streams.Length > 1 && IsRarFile(streams[1], ReaderOptions)) //test part 2 - true = multipart not split
         {
             sourceStream.IsVolumes = true;
             streams[1].Position = 0;
@@ -77,10 +63,17 @@ public partial class RarArchive
             ));
         }
 
+        //split mode or single file
         return new StreamRarArchiveVolume(sourceStream, ReaderOptions, i++).AsEnumerable();
     }
 
-    protected override IReader CreateReaderForSolidExtraction()
+    protected override IReader CreateReaderForSolidExtraction() =>
+        CreateReaderForSolidExtractionInternal();
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
+        new(CreateReaderForSolidExtractionInternal());
+
+    private RarReader CreateReaderForSolidExtractionInternal()
     {
         if (this.IsMultipartVolume())
         {
@@ -89,12 +82,12 @@ public partial class RarArchive
                 volume.Stream.Position = 0;
                 return volume.Stream;
             });
-            return (RarReader)RarReader.OpenReader(streams, ReaderOptions);
+            return RarReader.Open(streams, ReaderOptions);
         }
 
         var stream = Volumes.First().Stream;
         stream.Position = 0;
-        return (RarReader)RarReader.OpenReader(stream, ReaderOptions);
+        return RarReader.Open(stream, ReaderOptions);
     }
 
     public override bool IsSolid => Volumes.First().IsSolidArchive;
@@ -102,6 +95,188 @@ public partial class RarArchive
     public override bool IsEncrypted => Entries.First(x => !x.IsDirectory).IsEncrypted;
 
     public virtual int MinVersion => Volumes.First().MinVersion;
-
     public virtual int MaxVersion => Volumes.First().MaxVersion;
+
+    #region Creation
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="options"></param>
+    public static RarArchive Open(string filePath, ReaderOptions? options = null)
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        var fileInfo = new FileInfo(filePath);
+        return new RarArchive(
+            new SourceStream(
+                fileInfo,
+                i => RarArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                options ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="options"></param>
+    public static RarArchive Open(FileInfo fileInfo, ReaderOptions? options = null)
+    {
+        fileInfo.NotNull(nameof(fileInfo));
+        return new RarArchive(
+            new SourceStream(
+                fileInfo,
+                i => RarArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                options ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Takes a seekable Stream as a source
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="options"></param>
+    public static RarArchive Open(Stream stream, ReaderOptions? options = null)
+    {
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
+        return new RarArchive(new SourceStream(stream, _ => null, options ?? new ReaderOptions()));
+    }
+
+    /// <summary>
+    /// Constructor with all file parts passed in
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    public static RarArchive Open(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var files = fileInfos.ToArray();
+        return new RarArchive(
+            new SourceStream(
+                files[0],
+                i => i < files.Length ? files[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all stream parts passed in
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    public static RarArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
+    {
+        streams.NotNull(nameof(streams));
+        var strms = streams.ToArray();
+        return new RarArchive(
+            new SourceStream(
+                strms[0],
+                i => i < strms.Length ? strms[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(stream, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfo, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(streams, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfos, readerOptions));
+    }
+
+    public static bool IsRarFile(string filePath) => IsRarFile(new FileInfo(filePath));
+
+    public static bool IsRarFile(FileInfo fileInfo)
+    {
+        if (!fileInfo.Exists)
+        {
+            return false;
+        }
+        using Stream stream = fileInfo.OpenRead();
+        return IsRarFile(stream);
+    }
+
+    public static bool IsRarFile(Stream stream, ReaderOptions? options = null)
+    {
+        try
+        {
+            MarkHeader.Read(stream, true, false);
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    #endregion
 }

src/SharpCompress/Archives/Rar/RarArchiveEntry.Async.cs

@@ -1,43 +0,0 @@
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Rar;
-using SharpCompress.Common.Rar.Headers;
-using SharpCompress.Compressors.Rar;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.Rar;
-
-public partial class RarArchiveEntry
-{
-    public async ValueTask<Stream> OpenEntryStreamAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        RarStream stream;
-        if (IsRarV3)
-        {
-            stream = new RarStream(
-                archive.UnpackV1.Value,
-                FileHeader,
-                await MultiVolumeReadOnlyAsyncStream.Create(
-                    Parts.ToAsyncEnumerable().CastAsync<RarFilePart>()
-                )
-            );
-        }
-        else
-        {
-            stream = new RarStream(
-                archive.UnpackV2017.Value,
-                FileHeader,
-                await MultiVolumeReadOnlyAsyncStream.Create(
-                    Parts.ToAsyncEnumerable().CastAsync<RarFilePart>()
-                )
-            );
-        }
-
-        await stream.InitializeAsync(cancellationToken);
-        return stream;
-    }
-}

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

@@ -12,7 +12,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives.Rar;
 
-public partial class RarArchiveEntry : RarEntry, IArchiveEntry
+public class RarArchiveEntry : RarEntry, IArchiveEntry
 {
     private readonly ICollection<RarFilePart> parts;
     private readonly RarArchive archive;
@@ -92,6 +92,32 @@ public partial class RarArchiveEntry : RarEntry, IArchiveEntry
         return stream;
     }
 
+    public async ValueTask<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    )
+    {
+        RarStream stream;
+        if (IsRarV3)
+        {
+            stream = new RarStream(
+                archive.UnpackV1.Value,
+                FileHeader,
+                new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>())
+            );
+        }
+        else
+        {
+            stream = new RarStream(
+                archive.UnpackV2017.Value,
+                FileHeader,
+                new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>())
+            );
+        }
+
+        await stream.InitializeAsync(cancellationToken);
+        return stream;
+    }
+
     public bool IsComplete
     {
         get

src/SharpCompress/Archives/Rar/RarArchiveEntryFactory.cs

@@ -17,19 +17,6 @@ internal static class RarArchiveEntryFactory
         }
     }
 
-    private static async IAsyncEnumerable<RarFilePart> GetFilePartsAsync(
-        IAsyncEnumerable<RarVolume> parts
-    )
-    {
-        await foreach (var rarPart in parts)
-        {
-            await foreach (var fp in rarPart.ReadFilePartsAsync())
-            {
-                yield return fp;
-            }
-        }
-    }
-
     private static IEnumerable<IEnumerable<RarFilePart>> GetMatchedFileParts(
         IEnumerable<RarVolume> parts
     )
@@ -51,27 +38,6 @@ internal static class RarArchiveEntryFactory
         }
     }
 
-    private static async IAsyncEnumerable<IEnumerable<RarFilePart>> GetMatchedFilePartsAsync(
-        IAsyncEnumerable<RarVolume> parts
-    )
-    {
-        var groupedParts = new List<RarFilePart>();
-        await foreach (var fp in GetFilePartsAsync(parts))
-        {
-            groupedParts.Add(fp);
-
-            if (!fp.FileHeader.IsSplitAfter)
-            {
-                yield return groupedParts;
-                groupedParts = new List<RarFilePart>();
-            }
-        }
-        if (groupedParts.Count > 0)
-        {
-            yield return groupedParts;
-        }
-    }
-
     internal static IEnumerable<RarArchiveEntry> GetEntries(
         RarArchive archive,
         IEnumerable<RarVolume> rarParts,
@@ -83,16 +49,4 @@ internal static class RarArchiveEntryFactory
             yield return new RarArchiveEntry(archive, groupedParts, readerOptions);
         }
     }
-
-    internal static async IAsyncEnumerable<RarArchiveEntry> GetEntriesAsync(
-        RarArchive archive,
-        IAsyncEnumerable<RarVolume> rarParts,
-        ReaderOptions readerOptions
-    )
-    {
-        await foreach (var groupedParts in GetMatchedFilePartsAsync(rarParts))
-        {
-            yield return new RarArchiveEntry(archive, groupedParts, readerOptions);
-        }
-    }
 }

src/SharpCompress/Archives/Rar/RarArchiveVolumeFactory.cs

@@ -13,7 +13,6 @@ internal static class RarArchiveVolumeFactory
         //new style rar - ..part1 | /part01 | part001 ....
         var m = Regex.Match(part1.Name, @"^(.*\.part)([0-9]+)(\.rar)$", RegexOptions.IgnoreCase);
         if (m.Success)
-        {
             item = new FileInfo(
                 Path.Combine(
                     part1.DirectoryName!,
@@ -24,13 +23,11 @@ internal static class RarArchiveVolumeFactory
                     )
                 )
             );
-        }
         else
         {
             //old style - ...rar, .r00, .r01 ...
             m = Regex.Match(part1.Name, @"^(.*\.)([r-z{])(ar|[0-9]+)$", RegexOptions.IgnoreCase);
             if (m.Success)
-            {
                 item = new FileInfo(
                     Path.Combine(
                         part1.DirectoryName!,
@@ -43,17 +40,12 @@ internal static class RarArchiveVolumeFactory
                         )
                     )
                 );
-            }
             else //split .001, .002 ....
-            {
                 return ArchiveVolumeFactory.GetFilePart(index, part1);
-            }
         }
 
         if (item != null && item.Exists)
-        {
             return item;
-        }
 
         return null; //no more items
     }

src/SharpCompress/Archives/Rar/StreamRarArchiveVolume.cs

@@ -14,9 +14,6 @@ internal class StreamRarArchiveVolume : RarVolume
 
     internal override IEnumerable<RarFilePart> ReadFileParts() => GetVolumeFileParts();
 
-    internal override IAsyncEnumerable<RarFilePart> ReadFilePartsAsync() =>
-        GetVolumeFilePartsAsync();
-
     internal override RarFilePart CreateFilePart(MarkHeader markHeader, FileHeader fileHeader) =>
         new SeekableFilePart(markHeader, fileHeader, Index, Stream, ReaderOptions.Password);
 }

src/SharpCompress/Archives/SevenZip/SevenZipArchive.Async.cs

@@ -1,73 +0,0 @@
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.SevenZip;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.SevenZip;
-
-public partial class SevenZipArchive
-{
-    private async ValueTask LoadFactoryAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (_database is null)
-        {
-            stream.Position = 0;
-            var reader = new ArchiveReader();
-            await reader.OpenAsync(
-                stream,
-                lookForHeader: ReaderOptions.LookForHeader,
-                cancellationToken
-            );
-            _database = await reader.ReadDatabaseAsync(
-                new PasswordProvider(ReaderOptions.Password),
-                cancellationToken
-            );
-        }
-    }
-
-    protected override async IAsyncEnumerable<SevenZipArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<SevenZipVolume> volumes
-    )
-    {
-        var stream = (await volumes.SingleAsync()).Stream;
-        await LoadFactoryAsync(stream);
-        if (_database is null)
-        {
-            yield break;
-        }
-        var entries = new SevenZipArchiveEntry[_database._files.Count];
-        for (var i = 0; i < _database._files.Count; i++)
-        {
-            var file = _database._files[i];
-            entries[i] = new SevenZipArchiveEntry(
-                this,
-                new SevenZipFilePart(stream, _database, i, file, ReaderOptions.ArchiveEncoding)
-            );
-        }
-        foreach (var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder))
-        {
-            var isSolid = false;
-            foreach (var entry in group)
-            {
-                entry.IsSolid = isSolid;
-                isSolid = true;
-            }
-        }
-
-        foreach (var entry in entries)
-        {
-            yield return entry;
-        }
-    }
-
-    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
-        new(new SevenZipReader(ReaderOptions, this));
-}

src/SharpCompress/Archives/SevenZip/SevenZipArchive.Factory.cs

@@ -1,210 +0,0 @@
-using System;
-using System.Buffers;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.SevenZip;
-
-public partial class SevenZipArchive
-#if NET8_0_OR_GREATER
-    : IArchiveOpenable<IArchive, IAsyncArchive>,
-        IMultiArchiveOpenable<IArchive, IAsyncArchive>
-#endif
-{
-    public static IAsyncArchive OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        path.NotNullOrEmpty("path");
-        return (IAsyncArchive)OpenArchive(new FileInfo(path), readerOptions ?? new ReaderOptions());
-    }
-
-    public static IArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
-    {
-        filePath.NotNullOrEmpty("filePath");
-        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
-    }
-
-    public static IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null)
-    {
-        fileInfo.NotNull("fileInfo");
-        return new SevenZipArchive(
-            new SourceStream(
-                fileInfo,
-                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IArchive OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var files = fileInfos.ToArray();
-        return new SevenZipArchive(
-            new SourceStream(
-                files[0],
-                i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IArchive OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        streams.NotNull(nameof(streams));
-        var strms = streams.ToArray();
-        return new SevenZipArchive(
-            new SourceStream(
-                strms[0],
-                i => i < strms.Length ? strms[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
-    {
-        stream.NotNull("stream");
-
-        if (stream is not { CanSeek: true })
-        {
-            throw new ArgumentException("Stream must be seekable", nameof(stream));
-        }
-
-        return new SevenZipArchive(
-            new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
-        );
-    }
-
-    public static IAsyncArchive OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IAsyncArchive)OpenArchive(stream, readerOptions);
-    }
-
-    public static IAsyncArchive OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IAsyncArchive)OpenArchive(fileInfo, readerOptions);
-    }
-
-    public static IAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IAsyncArchive)OpenArchive(streams, readerOptions);
-    }
-
-    public static IAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IAsyncArchive)OpenArchive(fileInfos, readerOptions);
-    }
-
-    public static bool IsSevenZipFile(string filePath) => IsSevenZipFile(new FileInfo(filePath));
-
-    public static bool IsSevenZipFile(FileInfo fileInfo)
-    {
-        if (!fileInfo.Exists)
-        {
-            return false;
-        }
-        using Stream stream = fileInfo.OpenRead();
-        return IsSevenZipFile(stream);
-    }
-
-    public static bool IsSevenZipFile(Stream stream)
-    {
-        try
-        {
-            return SignatureMatch(stream);
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static async ValueTask<bool> IsSevenZipFileAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        try
-        {
-            return await SignatureMatchAsync(stream, cancellationToken);
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    private static ReadOnlySpan<byte> Signature => [(byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C];
-
-    private static bool SignatureMatch(Stream stream)
-    {
-        var buffer = ArrayPool<byte>.Shared.Rent(6);
-        try
-        {
-            stream.ReadExact(buffer, 0, 6);
-            return buffer.AsSpan().Slice(0, 6).SequenceEqual(Signature);
-        }
-        finally
-        {
-            ArrayPool<byte>.Shared.Return(buffer);
-        }
-    }
-
-    private static async ValueTask<bool> SignatureMatchAsync(
-        Stream stream,
-        CancellationToken cancellationToken
-    )
-    {
-        var buffer = ArrayPool<byte>.Shared.Rent(6);
-        try
-        {
-            if (!await stream.ReadFullyAsync(buffer, 0, 6, cancellationToken).ConfigureAwait(false))
-            {
-                return false;
-            }
-
-            return buffer.AsSpan().Slice(0, 6).SequenceEqual(Signature);
-        }
-        finally
-        {
-            ArrayPool<byte>.Shared.Return(buffer);
-        }
-    }
-}

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -12,10 +12,163 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives.SevenZip;
 
-public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVolume>
+public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVolume>
 {
     private ArchiveDatabase? _database;
 
+    /// <summary>
+    /// Constructor expects a filepath to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="readerOptions"></param>
+    public static SevenZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
+    {
+        filePath.NotNullOrEmpty("filePath");
+        return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
+    }
+
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    public static SevenZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+    {
+        fileInfo.NotNull("fileInfo");
+        return new SevenZipArchive(
+            new SourceStream(
+                fileInfo,
+                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all file parts passed in
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    public static SevenZipArchive Open(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var files = fileInfos.ToArray();
+        return new SevenZipArchive(
+            new SourceStream(
+                files[0],
+                i => i < files.Length ? files[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all stream parts passed in
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    public static SevenZipArchive Open(
+        IEnumerable<Stream> streams,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        streams.NotNull(nameof(streams));
+        var strms = streams.ToArray();
+        return new SevenZipArchive(
+            new SourceStream(
+                strms[0],
+                i => i < strms.Length ? strms[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Takes a seekable Stream as a source
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    public static SevenZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+    {
+        stream.NotNull("stream");
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
+        return new SevenZipArchive(
+            new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
+        );
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(stream, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfo, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(streams, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfos, readerOptions));
+    }
+
     /// <summary>
     /// Constructor with a SourceStream able to handle FileInfo and Streams.
     /// </summary>
@@ -29,6 +182,18 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
         return new SevenZipVolume(sourceStream, ReaderOptions, 0).AsEnumerable(); //simple single volume or split, multivolume not supported
     }
 
+    public static bool IsSevenZipFile(string filePath) => IsSevenZipFile(new FileInfo(filePath));
+
+    public static bool IsSevenZipFile(FileInfo fileInfo)
+    {
+        if (!fileInfo.Exists)
+        {
+            return false;
+        }
+        using Stream stream = fileInfo.OpenRead();
+        return IsSevenZipFile(stream);
+    }
+
     internal SevenZipArchive()
         : base(ArchiveType.SevenZip) { }
 
@@ -36,45 +201,32 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
         IEnumerable<SevenZipVolume> volumes
     )
     {
-        foreach (var volume in volumes)
+        var stream = volumes.Single().Stream;
+        LoadFactory(stream);
+        if (_database is null)
         {
-            LoadFactory(volume.Stream);
-            if (_database is null)
+            return Enumerable.Empty<SevenZipArchiveEntry>();
+        }
+        var entries = new SevenZipArchiveEntry[_database._files.Count];
+        for (var i = 0; i < _database._files.Count; i++)
+        {
+            var file = _database._files[i];
+            entries[i] = new SevenZipArchiveEntry(
+                this,
+                new SevenZipFilePart(stream, _database, i, file, ReaderOptions.ArchiveEncoding)
+            );
+        }
+        foreach (var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder))
+        {
+            var isSolid = false;
+            foreach (var entry in group)
             {
-                yield break;
-            }
-            var entries = new SevenZipArchiveEntry[_database._files.Count];
-            for (var i = 0; i < _database._files.Count; i++)
-            {
-                var file = _database._files[i];
-                entries[i] = new SevenZipArchiveEntry(
-                    this,
-                    new SevenZipFilePart(
-                        volume.Stream,
-                        _database,
-                        i,
-                        file,
-                        ReaderOptions.ArchiveEncoding
-                    )
-                );
-            }
-            foreach (
-                var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder)
-            )
-            {
-                var isSolid = false;
-                foreach (var entry in group)
-                {
-                    entry.IsSolid = isSolid;
-                    isSolid = true;
-                }
-            }
-
-            foreach (var entry in entries)
-            {
-                yield return entry;
+                entry.IsSolid = isSolid;
+                isSolid = true; //mark others in this group as solid - same as rar behaviour.
             }
         }
+
+        return entries;
     }
 
     private void LoadFactory(Stream stream)
@@ -88,9 +240,34 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
         }
     }
 
+    public static bool IsSevenZipFile(Stream stream)
+    {
+        try
+        {
+            return SignatureMatch(stream);
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    private static ReadOnlySpan<byte> Signature =>
+        new byte[] { (byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C };
+
+    private static bool SignatureMatch(Stream stream)
+    {
+        var reader = new BinaryReader(stream);
+        ReadOnlySpan<byte> signatureBytes = reader.ReadBytes(6);
+        return signatureBytes.SequenceEqual(Signature);
+    }
+
     protected override IReader CreateReaderForSolidExtraction() =>
         new SevenZipReader(ReaderOptions, this);
 
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
+        new(new SevenZipReader(ReaderOptions, this));
+
     public override bool IsSolid =>
         Entries
             .Where(x => !x.IsDirectory)
@@ -102,34 +279,13 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
     public override long TotalSize =>
         _database?._packSizes.Aggregate(0L, (total, packSize) => total + packSize) ?? 0;
 
-    internal sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
+    private sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
     {
         private readonly SevenZipArchive _archive;
         private SevenZipEntry? _currentEntry;
-        private Stream? _currentFolderStream;
-        private CFolder? _currentFolder;
-
-        /// <summary>
-        /// Enables internal diagnostics for tests.
-        /// When disabled (default), diagnostics properties return null to avoid exposing internal state.
-        /// </summary>
-        internal bool DiagnosticsEnabled { get; set; }
-
-        /// <summary>
-        /// Current folder instance used to decide whether the solid folder stream should be reused.
-        /// Only available when <see cref="DiagnosticsEnabled"/> is true.
-        /// </summary>
-        internal object? DiagnosticsCurrentFolder => DiagnosticsEnabled ? _currentFolder : null;
-
-        /// <summary>
-        /// Current shared folder stream instance.
-        /// Only available when <see cref="DiagnosticsEnabled"/> is true.
-        /// </summary>
-        internal Stream? DiagnosticsCurrentFolderStream =>
-            DiagnosticsEnabled ? _currentFolderStream : null;
 
         internal SevenZipReader(ReaderOptions readerOptions, SevenZipArchive archive)
-            : base(readerOptions, ArchiveType.SevenZip, false) => this._archive = archive;
+            : base(readerOptions, ArchiveType.SevenZip) => this._archive = archive;
 
         public override SevenZipVolume Volume => _archive.Volumes.Single();
 
@@ -142,10 +298,9 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
                 _currentEntry = dir;
                 yield return dir;
             }
-            // For solid archives (entries in the same folder share a compressed stream),
-            // we must iterate entries sequentially and maintain the folder stream state
-            // across entries in the same folder to avoid recreating the decompression
-            // stream for each file, which breaks contiguous streaming.
+            // For non-directory entries, yield them without creating shared streams
+            // Each call to GetEntryStream() will create a fresh decompression stream
+            // to avoid state corruption issues with async operations
             foreach (var entry in entries.Where(x => !x.IsDirectory))
             {
                 _currentEntry = entry;
@@ -155,46 +310,19 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
 
         protected override EntryStream GetEntryStream()
         {
+            // Create a fresh decompression stream for each file (no state sharing).
+            // However, the LZMA decoder has bugs in its async implementation that cause
+            // state corruption even on fresh streams. The SyncOnlyStream wrapper
+            // works around these bugs by forcing async operations to use sync equivalents.
+            //
+            // TODO: Fix the LZMA decoder async bugs (in LzmaStream, Decoder, OutWindow)
+            // so this wrapper is no longer necessary.
             var entry = _currentEntry.NotNull("currentEntry is not null");
             if (entry.IsDirectory)
             {
                 return CreateEntryStream(Stream.Null);
             }
-
-            var folder = entry.FilePart.Folder;
-
-            // Check if we're starting a new folder - dispose old folder stream if needed
-            if (folder != _currentFolder)
-            {
-                _currentFolderStream?.Dispose();
-                _currentFolderStream = null;
-                _currentFolder = folder;
-            }
-
-            // Create the folder stream once per folder
-            if (_currentFolderStream is null)
-            {
-                _currentFolderStream = _archive._database!.GetFolderStream(
-                    _archive.Volumes.Single().Stream,
-                    folder!,
-                    _archive._database.PasswordProvider
-                );
-            }
-
-            // Wrap with SyncOnlyStream to work around LZMA async bugs
-            // Return a ReadOnlySubStream that reads from the shared folder stream
-            return CreateEntryStream(
-                new SyncOnlyStream(
-                    new ReadOnlySubStream(_currentFolderStream, entry.Size, leaveOpen: true)
-                )
-            );
-        }
-
-        public override void Dispose()
-        {
-            _currentFolderStream?.Dispose();
-            _currentFolderStream = null;
-            base.Dispose();
+            return CreateEntryStream(new SyncOnlyStream(entry.FilePart.GetCompressedStream()));
         }
     }
 
@@ -267,7 +395,7 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
             return Task.CompletedTask;
         }
 
-#if !LEGACY_DOTNET
+#if !NETFRAMEWORK && !NETSTANDARD2_0
         public override ValueTask<int> ReadAsync(
             Memory<byte> buffer,
             CancellationToken cancellationToken = default

src/SharpCompress/Archives/SevenZip/SevenZipArchiveEntry.cs

@@ -14,7 +14,7 @@ public class SevenZipArchiveEntry : SevenZipEntry, IArchiveEntry
 
     public async ValueTask<Stream> OpenEntryStreamAsync(
         CancellationToken cancellationToken = default
-    ) => (await FilePart.GetCompressedStreamAsync(cancellationToken)).NotNull();
+    ) => OpenEntryStream();
 
     public IArchive Archive { get; }
 

src/SharpCompress/Archives/Tar/TarArchive.Async.cs

@@ -1,161 +0,0 @@
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Tar;
-using SharpCompress.Common.Tar.Headers;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Readers.Tar;
-using SharpCompress.Writers;
-using SharpCompress.Writers.Tar;
-
-namespace SharpCompress.Archives.Tar;
-
-public partial class TarArchive
-{
-    protected override async ValueTask SaveToAsync(
-        Stream stream,
-        WriterOptions options,
-        IAsyncEnumerable<TarArchiveEntry> oldEntries,
-        IEnumerable<TarArchiveEntry> newEntries,
-        CancellationToken cancellationToken = default
-    )
-    {
-        using var writer = new TarWriter(stream, new TarWriterOptions(options));
-        await foreach (
-            var entry in oldEntries.WithCancellation(cancellationToken).ConfigureAwait(false)
-        )
-        {
-            if (entry.IsDirectory)
-            {
-                await writer
-                    .WriteDirectoryAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entry.LastModifiedTime,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-            else
-            {
-                using var entryStream = entry.OpenEntryStream();
-                await writer
-                    .WriteAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entryStream,
-                        entry.LastModifiedTime,
-                        entry.Size,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-        foreach (var entry in newEntries)
-        {
-            if (entry.IsDirectory)
-            {
-                await writer
-                    .WriteDirectoryAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entry.LastModifiedTime,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-            else
-            {
-                using var entryStream = entry.OpenEntryStream();
-                await writer
-                    .WriteAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entryStream,
-                        entry.LastModifiedTime,
-                        entry.Size,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-
-    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
-    {
-        var stream = Volumes.Single().Stream;
-        stream.Position = 0;
-        return new((IAsyncReader)TarReader.OpenReader(stream));
-    }
-
-    protected override async IAsyncEnumerable<TarArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<TarVolume> volumes
-    )
-    {
-        var stream = (await volumes.SingleAsync()).Stream;
-        if (stream.CanSeek)
-        {
-            stream.Position = 0;
-        }
-
-        // Always use async header reading in LoadEntriesAsync for consistency
-        {
-            // Use async header reading for async-only streams
-            TarHeader? previousHeader = null;
-            await foreach (
-                var header in TarHeaderFactory.ReadHeaderAsync(
-                    StreamingMode.Seekable,
-                    stream,
-                    ReaderOptions.ArchiveEncoding
-                )
-            )
-            {
-                if (header != null)
-                {
-                    if (header.EntryType == EntryType.LongName)
-                    {
-                        previousHeader = header;
-                    }
-                    else
-                    {
-                        if (previousHeader != null)
-                        {
-                            var entry = new TarArchiveEntry(
-                                this,
-                                new TarFilePart(previousHeader, stream),
-                                CompressionType.None
-                            );
-
-                            var oldStreamPos = stream.Position;
-
-                            using (var entryStream = entry.OpenEntryStream())
-                            {
-                                using var memoryStream = new MemoryStream();
-                                await entryStream.CopyToAsync(memoryStream);
-                                memoryStream.Position = 0;
-                                var bytes = memoryStream.ToArray();
-
-                                header.Name = ReaderOptions
-                                    .ArchiveEncoding.Decode(bytes)
-                                    .TrimNulls();
-                            }
-
-                            stream.Position = oldStreamPos;
-
-                            previousHeader = null;
-                        }
-                        yield return new TarArchiveEntry(
-                            this,
-                            new TarFilePart(header, stream),
-                            CompressionType.None
-                        );
-                    }
-                }
-                else
-                {
-                    throw new IncompleteArchiveException("Failed to read TAR header");
-                }
-            }
-        }
-    }
-}

src/SharpCompress/Archives/Tar/TarArchive.Factory.cs

@@ -1,198 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Tar.Headers;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.Tar;
-
-public partial class TarArchive
-#if NET8_0_OR_GREATER
-    : IWritableArchiveOpenable,
-        IMultiArchiveOpenable<IWritableArchive, IWritableAsyncArchive>
-#endif
-{
-    public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
-    {
-        filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
-    }
-
-    public static IWritableArchive OpenArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfo.NotNull(nameof(fileInfo));
-        return new TarArchive(
-            new SourceStream(
-                fileInfo,
-                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var files = fileInfos.ToArray();
-        return new TarArchive(
-            new SourceStream(
-                files[0],
-                i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        streams.NotNull(nameof(streams));
-        var strms = streams.ToArray();
-        return new TarArchive(
-            new SourceStream(
-                strms[0],
-                i => i < strms.Length ? strms[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
-    {
-        stream.NotNull(nameof(stream));
-
-        if (stream is not { CanSeek: true })
-        {
-            throw new ArgumentException("Stream must be seekable", nameof(stream));
-        }
-
-        return new TarArchive(
-            new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
-        );
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(stream, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(new FileInfo(path), readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfo, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(streams, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
-    }
-
-    public static bool IsTarFile(string filePath) => IsTarFile(new FileInfo(filePath));
-
-    public static bool IsTarFile(FileInfo fileInfo)
-    {
-        if (!fileInfo.Exists)
-        {
-            return false;
-        }
-        using Stream stream = fileInfo.OpenRead();
-        return IsTarFile(stream);
-    }
-
-    public static bool IsTarFile(Stream stream)
-    {
-        try
-        {
-            var tarHeader = new TarHeader(new ArchiveEncoding());
-            var reader = new BinaryReader(stream, Encoding.UTF8, false);
-            var readSucceeded = tarHeader.Read(reader);
-            var isEmptyArchive =
-                tarHeader.Name?.Length == 0
-                && tarHeader.Size == 0
-                && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
-            return readSucceeded || isEmptyArchive;
-        }
-        catch (Exception)
-        {
-            // Catch all exceptions during tar header reading to determine if this is a valid tar file
-            // Invalid tar files or corrupted streams will throw various exceptions
-            return false;
-        }
-    }
-
-    public static async ValueTask<bool> IsTarFileAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        try
-        {
-            var tarHeader = new TarHeader(new ArchiveEncoding());
-            var reader = new AsyncBinaryReader(stream, false);
-            var readSucceeded = await tarHeader.ReadAsync(reader);
-            var isEmptyArchive =
-                tarHeader.Name?.Length == 0
-                && tarHeader.Size == 0
-                && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
-            return readSucceeded || isEmptyArchive;
-        }
-        catch (Exception)
-        {
-            // Catch all exceptions during tar header reading to determine if this is a valid tar file
-            // Invalid tar files or corrupted streams will throw various exceptions
-            return false;
-        }
-    }
-
-    public static IWritableArchive CreateArchive() => new TarArchive();
-
-    public static IWritableAsyncArchive CreateAsyncArchive() => new TarArchive();
-}

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -15,14 +15,196 @@ using SharpCompress.Writers.Tar;
 
 namespace SharpCompress.Archives.Tar;
 
-public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
+public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
 {
-    protected override IEnumerable<TarVolume> LoadVolumes(SourceStream sourceStream)
+    /// <summary>
+    /// Constructor expects a filepath to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="readerOptions"></param>
+    public static TarArchive Open(string filePath, ReaderOptions? readerOptions = null)
     {
-        sourceStream.NotNull("SourceStream is null").LoadAllParts();
-        return new TarVolume(sourceStream, ReaderOptions, 1).AsEnumerable();
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    public static TarArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+    {
+        fileInfo.NotNull(nameof(fileInfo));
+        return new TarArchive(
+            new SourceStream(
+                fileInfo,
+                i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all file parts passed in
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    public static TarArchive Open(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var files = fileInfos.ToArray();
+        return new TarArchive(
+            new SourceStream(
+                files[0],
+                i => i < files.Length ? files[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all stream parts passed in
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    public static TarArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
+    {
+        streams.NotNull(nameof(streams));
+        var strms = streams.ToArray();
+        return new TarArchive(
+            new SourceStream(
+                strms[0],
+                i => i < strms.Length ? strms[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Takes a seekable Stream as a source
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    public static TarArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+    {
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
+        return new TarArchive(
+            new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
+        );
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(stream, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfo, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(streams, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfos, readerOptions));
+    }
+
+    public static bool IsTarFile(string filePath) => IsTarFile(new FileInfo(filePath));
+
+    public static bool IsTarFile(FileInfo fileInfo)
+    {
+        if (!fileInfo.Exists)
+        {
+            return false;
+        }
+        using Stream stream = fileInfo.OpenRead();
+        return IsTarFile(stream);
+    }
+
+    public static bool IsTarFile(Stream stream)
+    {
+        try
+        {
+            var tarHeader = new TarHeader(new ArchiveEncoding());
+            var readSucceeded = tarHeader.Read(new BinaryReader(stream));
+            var isEmptyArchive =
+                tarHeader.Name?.Length == 0
+                && tarHeader.Size == 0
+                && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
+            return readSucceeded || isEmptyArchive;
+        }
+        catch { }
+        return false;
+    }
+
+    protected override IEnumerable<TarVolume> LoadVolumes(SourceStream sourceStream)
+    {
+        sourceStream.NotNull("SourceStream is null").LoadAllParts(); //request all streams
+        return new TarVolume(sourceStream, ReaderOptions, 1).AsEnumerable(); //simple single volume or split, multivolume not supported
+    }
+
+    /// <summary>
+    /// Constructor with a SourceStream able to handle FileInfo and Streams.
+    /// </summary>
+    /// <param name="sourceStream"></param>
     private TarArchive(SourceStream sourceStream)
         : base(ArchiveType.Tar, sourceStream) { }
 
@@ -32,10 +214,6 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
     protected override IEnumerable<TarArchiveEntry> LoadEntries(IEnumerable<TarVolume> volumes)
     {
         var stream = volumes.Single().Stream;
-        if (stream.CanSeek)
-        {
-            stream.Position = 0;
-        }
         TarHeader? previousHeader = null;
         foreach (
             var header in TarHeaderFactory.ReadHeader(
@@ -66,7 +244,7 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
                         using (var entryStream = entry.OpenEntryStream())
                         {
                             using var memoryStream = new MemoryStream();
-                            entryStream.CopyTo(memoryStream, Constants.BufferSize);
+                            entryStream.CopyTo(memoryStream);
                             memoryStream.Position = 0;
                             var bytes = memoryStream.ToArray();
 
@@ -91,6 +269,8 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
         }
     }
 
+    public static TarArchive Create() => new();
+
     protected override TarArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -143,10 +323,54 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<TarArchiveEntry> oldEntries,
+        IEnumerable<TarArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var writer = new TarWriter(stream, new TarWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries))
+        {
+            if (entry.IsDirectory)
+            {
+                await writer
+                    .WriteDirectoryAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entry.LastModifiedTime,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                await writer
+                    .WriteAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entryStream,
+                        entry.LastModifiedTime,
+                        entry.Size,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+        }
+    }
+
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
-        return TarReader.OpenReader(stream);
+        return TarReader.Open(stream);
+    }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new(TarReader.Open(stream));
     }
 }

src/SharpCompress/Archives/Tar/TarArchiveEntry.cs

@@ -14,8 +14,9 @@ public class TarArchiveEntry : TarEntry, IArchiveEntry
 
     public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream().NotNull();
 
-    public ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default) =>
-        new(OpenEntryStream());
+    public async ValueTask<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    ) => OpenEntryStream();
 
     #region IArchiveEntry Members
 

src/SharpCompress/Archives/Zip/ZipArchive.Async.cs

@@ -1,132 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Zip;
-using SharpCompress.Common.Zip.Headers;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-using SharpCompress.Writers;
-using SharpCompress.Writers.Zip;
-
-namespace SharpCompress.Archives.Zip;
-
-public partial class ZipArchive
-{
-    protected override async IAsyncEnumerable<ZipArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<ZipVolume> volumes
-    )
-    {
-        var vols = await volumes.ToListAsync();
-        var volsArray = vols.ToArray();
-
-        await foreach (
-            var h in headerFactory.NotNull().ReadSeekableHeaderAsync(volsArray.Last().Stream)
-        )
-        {
-            if (h != null)
-            {
-                switch (h.ZipHeaderType)
-                {
-                    case ZipHeaderType.DirectoryEntry:
-                        {
-                            var deh = (DirectoryEntryHeader)h;
-                            Stream s;
-                            if (
-                                deh.RelativeOffsetOfEntryHeader + deh.CompressedSize
-                                > volsArray[deh.DiskNumberStart].Stream.Length
-                            )
-                            {
-                                var v = volsArray.Skip(deh.DiskNumberStart).ToArray();
-                                s = new SourceStream(
-                                    v[0].Stream,
-                                    i => i < v.Length ? v[i].Stream : null,
-                                    new ReaderOptions() { LeaveStreamOpen = true }
-                                );
-                            }
-                            else
-                            {
-                                s = volsArray[deh.DiskNumberStart].Stream;
-                            }
-
-                            yield return new ZipArchiveEntry(
-                                this,
-                                new SeekableZipFilePart(headerFactory.NotNull(), deh, s)
-                            );
-                        }
-                        break;
-                    case ZipHeaderType.DirectoryEnd:
-                    {
-                        var bytes = ((DirectoryEndHeader)h).Comment ?? Array.Empty<byte>();
-                        volsArray.Last().Comment = ReaderOptions.ArchiveEncoding.Decode(bytes);
-                        yield break;
-                    }
-                }
-            }
-        }
-    }
-
-    protected override async ValueTask SaveToAsync(
-        Stream stream,
-        WriterOptions options,
-        IAsyncEnumerable<ZipArchiveEntry> oldEntries,
-        IEnumerable<ZipArchiveEntry> newEntries,
-        CancellationToken cancellationToken = default
-    )
-    {
-        using var writer = new ZipWriter(stream, new ZipWriterOptions(options));
-        await foreach (
-            var entry in oldEntries.WithCancellation(cancellationToken).ConfigureAwait(false)
-        )
-        {
-            if (entry.IsDirectory)
-            {
-                await writer
-                    .WriteDirectoryAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entry.LastModifiedTime,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-            else
-            {
-                using var entryStream = entry.OpenEntryStream();
-                await writer
-                    .WriteAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entryStream,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-        foreach (var entry in newEntries)
-        {
-            if (entry.IsDirectory)
-            {
-                await writer
-                    .WriteDirectoryAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entry.LastModifiedTime,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-            else
-            {
-                using var entryStream = entry.OpenEntryStream();
-                await writer
-                    .WriteAsync(
-                        entry.Key.NotNull("Entry Key is null"),
-                        entryStream,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-}

src/SharpCompress/Archives/Zip/ZipArchive.Factory.cs

@@ -1,302 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Common.Zip;
-using SharpCompress.Common.Zip.Headers;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.Zip;
-
-public partial class ZipArchive
-#if NET8_0_OR_GREATER
-    : IWritableArchiveOpenable,
-        IMultiArchiveOpenable<IWritableArchive, IWritableAsyncArchive>
-#endif
-{
-    public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
-    {
-        filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
-    }
-
-    public static IWritableArchive OpenArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfo.NotNull(nameof(fileInfo));
-        return new ZipArchive(
-            new SourceStream(
-                fileInfo,
-                i => ZipArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        fileInfos.NotNull(nameof(fileInfos));
-        var files = fileInfos.ToArray();
-        return new ZipArchive(
-            new SourceStream(
-                files[0],
-                i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(
-        IEnumerable<Stream> streams,
-        ReaderOptions? readerOptions = null
-    )
-    {
-        streams.NotNull(nameof(streams));
-        var strms = streams.ToArray();
-        return new ZipArchive(
-            new SourceStream(
-                strms[0],
-                i => i < strms.Length ? strms[i] : null,
-                readerOptions ?? new ReaderOptions()
-            )
-        );
-    }
-
-    public static IWritableArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
-    {
-        stream.NotNull(nameof(stream));
-
-        if (stream is not { CanSeek: true })
-        {
-            throw new ArgumentException("Stream must be seekable", nameof(stream));
-        }
-
-        return new ZipArchive(
-            new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
-        );
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        string path,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(path, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(stream, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        FileInfo fileInfo,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfo, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<Stream> streams,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(streams, readerOptions);
-    }
-
-    public static IWritableAsyncArchive OpenAsyncArchive(
-        IReadOnlyList<FileInfo> fileInfos,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
-    }
-
-    public static bool IsZipFile(string filePath, string? password = null) =>
-        IsZipFile(new FileInfo(filePath), password);
-
-    public static bool IsZipFile(FileInfo fileInfo, string? password = null)
-    {
-        if (!fileInfo.Exists)
-        {
-            return false;
-        }
-        using Stream stream = fileInfo.OpenRead();
-        return IsZipFile(stream, password);
-    }
-
-    public static bool IsZipFile(Stream stream, string? password = null)
-    {
-        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
-        try
-        {
-            var header = headerFactory
-                .ReadStreamHeader(stream)
-                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
-            if (header is null)
-            {
-                return false;
-            }
-            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
-        }
-        catch (CryptographicException)
-        {
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static bool IsZipMulti(Stream stream, string? password = null)
-    {
-        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
-        try
-        {
-            if (stream is not SharpCompressStream)
-            {
-                stream = new SharpCompressStream(stream, bufferSize: Constants.BufferSize);
-            }
-
-            var header = headerFactory
-                .ReadStreamHeader(stream)
-                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
-            if (header is null)
-            {
-                if (stream.CanSeek)
-                {
-                    var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    var x = z.ReadSeekableHeader(stream).FirstOrDefault();
-                    return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
-                }
-                else
-                {
-                    return false;
-                }
-            }
-            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
-        }
-        catch (CryptographicException)
-        {
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static async ValueTask<bool> IsZipFileAsync(
-        Stream stream,
-        string? password = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
-        try
-        {
-            if (stream is not SharpCompressStream)
-            {
-                stream = new SharpCompressStream(stream, bufferSize: Constants.BufferSize);
-            }
-
-            var header = await headerFactory
-                .ReadStreamHeaderAsync(stream)
-                .Where(x => x.ZipHeaderType != ZipHeaderType.Split)
-                .FirstOrDefaultAsync(cancellationToken);
-            if (header is null)
-            {
-                return false;
-            }
-            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
-        }
-        catch (CryptographicException)
-        {
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
-    public static IWritableArchive CreateArchive() => new ZipArchive();
-
-    public static IWritableAsyncArchive CreateAsyncArchive() => new ZipArchive();
-
-    public static async ValueTask<bool> IsZipMultiAsync(
-        Stream stream,
-        string? password = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
-        try
-        {
-            if (stream is not SharpCompressStream)
-            {
-                stream = new SharpCompressStream(stream, bufferSize: Constants.BufferSize);
-            }
-
-            var header = headerFactory
-                .ReadStreamHeader(stream)
-                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
-            if (header is null)
-            {
-                if (stream.CanSeek)
-                {
-                    var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    ZipHeader? x = null;
-                    await foreach (
-                        var h in z.ReadSeekableHeaderAsync(stream)
-                            .WithCancellation(cancellationToken)
-                    )
-                    {
-                        x = h;
-                        break;
-                    }
-                    return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
-                }
-                else
-                {
-                    return false;
-                }
-            }
-            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
-        }
-        catch (CryptographicException)
-        {
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-}

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -16,12 +16,21 @@ using SharpCompress.Writers.Zip;
 
 namespace SharpCompress.Archives.Zip;
 
-public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
+public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
 {
     private readonly SeekableZipHeaderFactory? headerFactory;
 
+    /// <summary>
+    /// Gets or sets the compression level applied to files added to the archive,
+    /// if the compression method is set to deflate
+    /// </summary>
     public CompressionLevel DeflateCompressionLevel { get; set; }
 
+    /// <summary>
+    /// Constructor with a SourceStream able to handle FileInfo and Streams.
+    /// </summary>
+    /// <param name="sourceStream"></param>
+    /// <param name="options"></param>
     internal ZipArchive(SourceStream sourceStream)
         : base(ArchiveType.Zip, sourceStream) =>
         headerFactory = new SeekableZipHeaderFactory(
@@ -29,43 +38,377 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
             sourceStream.ReaderOptions.ArchiveEncoding
         );
 
-    internal ZipArchive()
-        : base(ArchiveType.Zip) { }
+    /// <summary>
+    /// Constructor expects a filepath to an existing file.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="readerOptions"></param>
+    public static ZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
+    }
+
+    /// <summary>
+    /// Constructor with a FileInfo object to an existing file.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    public static ZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+    {
+        fileInfo.NotNull(nameof(fileInfo));
+        return new ZipArchive(
+            new SourceStream(
+                fileInfo,
+                i => ZipArchiveVolumeFactory.GetFilePart(i, fileInfo),
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all file parts passed in
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    public static ZipArchive Open(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var files = fileInfos.ToArray();
+        return new ZipArchive(
+            new SourceStream(
+                files[0],
+                i => i < files.Length ? files[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Constructor with all stream parts passed in
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    public static ZipArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
+    {
+        streams.NotNull(nameof(streams));
+        var strms = streams.ToArray();
+        return new ZipArchive(
+            new SourceStream(
+                strms[0],
+                i => i < strms.Length ? strms[i] : null,
+                readerOptions ?? new ReaderOptions()
+            )
+        );
+    }
+
+    /// <summary>
+    /// Takes a seekable Stream as a source
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    public static ZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+    {
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
+        return new ZipArchive(
+            new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
+        );
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(stream, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfo, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(streams, readerOptions));
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static ValueTask<IAsyncArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return new(Open(fileInfos, readerOptions));
+    }
+
+    public static bool IsZipFile(
+        string filePath,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    ) => IsZipFile(new FileInfo(filePath), password, bufferSize);
+
+    public static bool IsZipFile(
+        FileInfo fileInfo,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
+    {
+        if (!fileInfo.Exists)
+        {
+            return false;
+        }
+        using Stream stream = fileInfo.OpenRead();
+        return IsZipFile(stream, password, bufferSize);
+    }
+
+    public static bool IsZipFile(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
+    {
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = headerFactory
+                .ReadStreamHeader(stream)
+                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+            if (header is null)
+            {
+                return false;
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    public static bool IsZipMulti(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
+    {
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = headerFactory
+                .ReadStreamHeader(stream)
+                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+            if (header is null)
+            {
+                if (stream.CanSeek) //could be multipart. Test for central directory - might not be z64 safe
+                {
+                    var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
+                    var x = z.ReadSeekableHeader(stream, useSync: true).FirstOrDefault();
+                    return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    public static async ValueTask<bool> IsZipFileAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = await headerFactory
+                .ReadStreamHeaderAsync(stream)
+                .Where(x => x.ZipHeaderType != ZipHeaderType.Split)
+                .FirstOrDefaultAsync();
+            if (header is null)
+            {
+                return false;
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    public static async ValueTask<bool> IsZipMultiAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = headerFactory
+                .ReadStreamHeader(stream)
+                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+            if (header is null)
+            {
+                if (stream.CanSeek) //could be multipart. Test for central directory - might not be z64 safe
+                {
+                    var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
+                    ZipHeader? x = null;
+                    await foreach (
+                        var h in z.ReadSeekableHeaderAsync(stream)
+                            .WithCancellation(cancellationToken)
+                    )
+                    {
+                        x = h;
+                        break;
+                    }
+                    return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
 
     protected override IEnumerable<ZipVolume> LoadVolumes(SourceStream stream)
     {
-        stream.LoadAllParts();
+        stream.LoadAllParts(); //request all streams
         stream.Position = 0;
 
         var streams = stream.Streams.ToList();
         var idx = 0;
-        if (streams.Count() > 1)
+        if (streams.Count() > 1) //test part 2 - true = multipart not split
         {
-            //check if second stream is zip header without changing position
-            var headerProbeStream = streams[1];
-            var startPosition = headerProbeStream.Position;
-            headerProbeStream.Position = startPosition + 4;
-            var isZip = IsZipFile(headerProbeStream, ReaderOptions.Password);
-            headerProbeStream.Position = startPosition;
+            streams[1].Position += 4; //skip the POST_DATA_DESCRIPTOR to prevent an exception
+            var isZip = IsZipFile(streams[1], ReaderOptions.Password, ReaderOptions.BufferSize);
+            streams[1].Position -= 4;
             if (isZip)
             {
                 stream.IsVolumes = true;
 
-                var tmp = streams[0];
+                var tmp = streams[0]; //arcs as zip, z01 ... swap the zip the end
                 streams.RemoveAt(0);
                 streams.Add(tmp);
 
+                //streams[0].Position = 4; //skip the POST_DATA_DESCRIPTOR to prevent an exception
                 return streams.Select(a => new ZipVolume(a, ReaderOptions, idx++));
             }
         }
 
+        //split mode or single file
         return new ZipVolume(stream, ReaderOptions, idx++).AsEnumerable();
     }
 
+    internal ZipArchive()
+        : base(ArchiveType.Zip) { }
+
     protected override IEnumerable<ZipArchiveEntry> LoadEntries(IEnumerable<ZipVolume> volumes)
     {
         var vols = volumes.ToArray();
-        foreach (var h in headerFactory.NotNull().ReadSeekableHeader(vols.Last().Stream))
+        foreach (
+            var h in headerFactory.NotNull().ReadSeekableHeader(vols.Last().Stream, useSync: true)
+        )
         {
             if (h != null)
             {
@@ -109,6 +452,59 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         }
     }
 
+    protected override async IAsyncEnumerable<ZipArchiveEntry> LoadEntriesAsync(
+        IAsyncEnumerable<ZipVolume> volumes
+    )
+    {
+        var vols = await volumes.ToListAsync();
+        var volsArray = vols.ToArray();
+
+        await foreach (
+            var h in headerFactory.NotNull().ReadSeekableHeaderAsync(volsArray.Last().Stream)
+        )
+        {
+            if (h != null)
+            {
+                switch (h.ZipHeaderType)
+                {
+                    case ZipHeaderType.DirectoryEntry:
+                        {
+                            var deh = (DirectoryEntryHeader)h;
+                            Stream s;
+                            if (
+                                deh.RelativeOffsetOfEntryHeader + deh.CompressedSize
+                                > volsArray[deh.DiskNumberStart].Stream.Length
+                            )
+                            {
+                                var v = volsArray.Skip(deh.DiskNumberStart).ToArray();
+                                s = new SourceStream(
+                                    v[0].Stream,
+                                    i => i < v.Length ? v[i].Stream : null,
+                                    new ReaderOptions() { LeaveStreamOpen = true }
+                                );
+                            }
+                            else
+                            {
+                                s = volsArray[deh.DiskNumberStart].Stream;
+                            }
+
+                            yield return new ZipArchiveEntry(
+                                this,
+                                new SeekableZipFilePart(headerFactory.NotNull(), deh, s)
+                            );
+                        }
+                        break;
+                    case ZipHeaderType.DirectoryEnd:
+                    {
+                        var bytes = ((DirectoryEndHeader)h).Comment ?? Array.Empty<byte>();
+                        volsArray.Last().Comment = ReaderOptions.ArchiveEncoding.Decode(bytes);
+                        yield break;
+                    }
+                }
+            }
+        }
+    }
+
     public void SaveTo(Stream stream) => SaveTo(stream, new WriterOptions(CompressionType.Deflate));
 
     protected override void SaveTo(
@@ -140,6 +536,41 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<ZipArchiveEntry> oldEntries,
+        IEnumerable<ZipArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var writer = new ZipWriter(stream, new ZipWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries))
+        {
+            if (entry.IsDirectory)
+            {
+                await writer
+                    .WriteDirectoryAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entry.LastModifiedTime,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                await writer
+                    .WriteAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entryStream,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+        }
+    }
+
     protected override ZipArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -153,17 +584,19 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         DateTime? modified
     ) => new ZipWritableArchiveEntry(this, directoryPath, modified);
 
+    public static ZipArchive Create() => new();
+
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
         ((IStreamStack)stream).StackSeek(0);
-        return ZipReader.OpenReader(stream, ReaderOptions, Entries);
+        return ZipReader.Open(stream, ReaderOptions, Entries);
     }
 
     protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
-        return new((IAsyncReader)ZipReader.OpenReader(stream));
+        return new(ZipReader.Open(stream));
     }
 }

src/SharpCompress/Archives/Zip/ZipArchiveEntry.Async.cs

@@ -1,22 +0,0 @@
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Zip;
-
-namespace SharpCompress.Archives.Zip;
-
-public partial class ZipArchiveEntry
-{
-    public async ValueTask<Stream> OpenEntryStreamAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var part = Parts.Single();
-        if (part is SeekableZipFilePart seekablePart)
-        {
-            return (await seekablePart.GetCompressedStreamAsync(cancellationToken)).NotNull();
-        }
-        return OpenEntryStream();
-    }
-}

src/SharpCompress/Archives/Zip/ZipArchiveEntry.cs

@@ -6,13 +6,25 @@ using SharpCompress.Common.Zip;
 
 namespace SharpCompress.Archives.Zip;
 
-public partial class ZipArchiveEntry : ZipEntry, IArchiveEntry
+public class ZipArchiveEntry : ZipEntry, IArchiveEntry
 {
     internal ZipArchiveEntry(ZipArchive archive, SeekableZipFilePart? part)
         : base(part) => Archive = archive;
 
     public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream().NotNull();
 
+    public async ValueTask<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    )
+    {
+        var part = Parts.Single();
+        if (part is SeekableZipFilePart seekablePart)
+        {
+            return (await seekablePart.GetCompressedStreamAsync(cancellationToken)).NotNull();
+        }
+        return OpenEntryStream();
+    }
+
     #region IArchiveEntry Members
 
     public IArchive Archive { get; }

src/SharpCompress/Archives/Zip/ZipArchiveVolumeFactory.cs

@@ -14,7 +14,6 @@ internal static class ZipArchiveVolumeFactory
         //new style .zip, z01.. | .zipx, zx01 - if the numbers go beyond 99 then they use 100 ...1000 etc
         var m = Regex.Match(part1.Name, @"^(.*\.)(zipx?|zx?[0-9]+)$", RegexOptions.IgnoreCase);
         if (m.Success)
-        {
             item = new FileInfo(
                 Path.Combine(
                     part1.DirectoryName!,
@@ -25,16 +24,11 @@ internal static class ZipArchiveVolumeFactory
                     )
                 )
             );
-        }
         else //split - 001, 002 ...
-        {
             return ArchiveVolumeFactory.GetFilePart(index, part1);
-        }
 
         if (item != null && item.Exists)
-        {
             return item;
-        }
 
         return null; //no more items
     }

src/SharpCompress/Common/Ace/AceCrc.cs

@@ -22,13 +22,9 @@ namespace SharpCompress.Common.Ace
                 for (int j = 0; j < 8; j++)
                 {
                     if ((crc & 1) != 0)
-                    {
                         crc = (crc >> 1) ^ 0xEDB88320u;
-                    }
                     else
-                    {
                         crc >>= 1;
-                    }
                 }
 
                 table[i] = crc;

src/SharpCompress/Common/Ace/Headers/AceFileHeader.Async.cs

@@ -1,111 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Arc;
-
-namespace SharpCompress.Common.Ace.Headers;
-
-public sealed partial class AceFileHeader
-{
-    /// <summary>
-    /// Asynchronously reads the next file entry header from the stream.
-    /// Returns null if no more entries or end of archive.
-    /// Supports both ACE 1.0 and ACE 2.0 formats.
-    /// </summary>
-    public override async ValueTask<AceHeader?> ReadAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var headerData = await ReadHeaderAsync(stream, cancellationToken);
-        if (headerData.Length == 0)
-        {
-            return null;
-        }
-        int offset = 0;
-
-        // Header type (1 byte)
-        HeaderType = headerData[offset++];
-
-        // Skip recovery record headers (ACE 2.0 feature)
-        if (HeaderType == (byte)SharpCompress.Common.Ace.Headers.AceHeaderType.RECOVERY32)
-        {
-            // Skip to next header
-            return null;
-        }
-
-        if (HeaderType != (byte)SharpCompress.Common.Ace.Headers.AceHeaderType.FILE)
-        {
-            // Unknown header type - skip
-            return null;
-        }
-
-        // Header flags (2 bytes)
-        HeaderFlags = BitConverter.ToUInt16(headerData, offset);
-        offset += 2;
-
-        // Packed size (4 bytes)
-        PackedSize = BitConverter.ToUInt32(headerData, offset);
-        offset += 4;
-
-        // Original size (4 bytes)
-        OriginalSize = BitConverter.ToUInt32(headerData, offset);
-        offset += 4;
-
-        // File date/time in DOS format (4 bytes)
-        var dosDateTime = BitConverter.ToUInt32(headerData, offset);
-        DateTime = ConvertDosDateTime(dosDateTime);
-        offset += 4;
-
-        // File attributes (4 bytes)
-        Attributes = (int)BitConverter.ToUInt32(headerData, offset);
-        offset += 4;
-
-        // CRC32 (4 bytes)
-        Crc32 = BitConverter.ToUInt32(headerData, offset);
-        offset += 4;
-
-        // Compression type (1 byte)
-        byte compressionType = headerData[offset++];
-        CompressionType = GetCompressionType(compressionType);
-
-        // Compression quality/parameter (1 byte)
-        byte compressionQuality = headerData[offset++];
-        CompressionQuality = GetCompressionQuality(compressionQuality);
-
-        // Parameters (2 bytes)
-        Parameters = BitConverter.ToUInt16(headerData, offset);
-        offset += 2;
-
-        // Reserved (2 bytes) - skip
-        offset += 2;
-
-        // Filename length (2 bytes)
-        var filenameLength = BitConverter.ToUInt16(headerData, offset);
-        offset += 2;
-
-        // Filename
-        if (offset + filenameLength <= headerData.Length)
-        {
-            Filename = ArchiveEncoding.Decode(headerData, offset, filenameLength);
-            offset += filenameLength;
-        }
-
-        // Handle comment if present
-        if ((HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.COMMENT) != 0)
-        {
-            // Comment length (2 bytes)
-            if (offset + 2 <= headerData.Length)
-            {
-                ushort commentLength = BitConverter.ToUInt16(headerData, offset);
-                offset += 2 + commentLength; // Skip comment
-            }
-        }
-
-        // Store the data start position
-        DataStartPosition = stream.Position;
-
-        return this;
-    }
-}

src/SharpCompress/Common/Ace/Headers/AceFileHeader.cs

@@ -2,8 +2,6 @@ using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Xml.Linq;
 using SharpCompress.Common.Arc;
 
@@ -12,7 +10,7 @@ namespace SharpCompress.Common.Ace.Headers
     /// <summary>
     /// ACE file entry header
     /// </summary>
-    public sealed partial class AceFileHeader : AceHeader
+    public sealed class AceFileHeader : AceHeader
     {
         public long DataStartPosition { get; private set; }
         public long PackedSize { get; set; }
@@ -149,8 +147,6 @@ namespace SharpCompress.Common.Ace.Headers
             return this;
         }
 
-        // ReadAsync moved to AceFileHeader.Async.cs
-
         public CompressionType GetCompressionType(byte value) =>
             value switch
             {

src/SharpCompress/Common/Ace/Headers/AceHeader.Async.cs

@@ -1,69 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common.Ace.Headers;
-
-public abstract partial class AceHeader
-{
-    public abstract ValueTask<AceHeader?> ReadAsync(
-        Stream reader,
-        CancellationToken cancellationToken = default
-    );
-
-    public async ValueTask<byte[]> ReadHeaderAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        // Read header CRC (2 bytes) and header size (2 bytes)
-        var headerBytes = new byte[4];
-        if (await stream.ReadAsync(headerBytes, 0, 4, cancellationToken) != 4)
-        {
-            return Array.Empty<byte>();
-        }
-
-        HeaderCrc = BitConverter.ToUInt16(headerBytes, 0); // CRC for validation
-        HeaderSize = BitConverter.ToUInt16(headerBytes, 2);
-        if (HeaderSize == 0)
-        {
-            return Array.Empty<byte>();
-        }
-
-        // Read the header data
-        var body = new byte[HeaderSize];
-        if (await stream.ReadAsync(body, 0, HeaderSize, cancellationToken) != HeaderSize)
-        {
-            return Array.Empty<byte>();
-        }
-
-        // Verify crc
-        var checksum = AceCrc.AceCrc16(body);
-        if (checksum != HeaderCrc)
-        {
-            throw new InvalidDataException("Header checksum is invalid");
-        }
-        return body;
-    }
-
-    /// <summary>
-    /// Asynchronously checks if the stream is an ACE archive
-    /// </summary>
-    /// <param name="stream">The stream to read from</param>
-    /// <param name="cancellationToken">Cancellation token</param>
-    /// <returns>True if the stream is an ACE archive, false otherwise</returns>
-    public static async ValueTask<bool> IsArchiveAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = new byte[14];
-        if (await stream.ReadAsync(bytes, 0, 14, cancellationToken) != 14)
-        {
-            return false;
-        }
-
-        return CheckMagicBytes(bytes, 7);
-    }
-}

src/SharpCompress/Common/Ace/Headers/AceHeader.cs

@@ -1,7 +1,5 @@
 using System;
 using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common.Arj.Headers;
 using SharpCompress.Crypto;
 
@@ -19,7 +17,7 @@ namespace SharpCompress.Common.Ace.Headers
         RECOVERY64B = 4,
     }
 
-    public abstract partial class AceHeader
+    public abstract class AceHeader
     {
         // ACE signature: bytes at offset 7 should be "**ACE**"
         private static readonly byte[] AceSignature =
@@ -60,8 +58,6 @@ namespace SharpCompress.Common.Ace.Headers
 
         public abstract AceHeader? Read(Stream reader);
 
-        // Async methods moved to AceHeader.Async.cs
-
         public byte[] ReadHeader(Stream stream)
         {
             // Read header CRC (2 bytes) and header size (2 bytes)

src/SharpCompress/Common/Ace/Headers/AceMainHeader.Async.cs

@@ -1,83 +0,0 @@
-using System;
-using System.Buffers.Binary;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Crypto;
-
-namespace SharpCompress.Common.Ace.Headers;
-
-public sealed partial class AceMainHeader
-{
-    /// <summary>
-    /// Asynchronously reads the main archive header from the stream.
-    /// Returns header if this is a valid ACE archive.
-    /// Supports both ACE 1.0 and ACE 2.0 formats.
-    /// </summary>
-    public override async ValueTask<AceHeader?> ReadAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var headerData = await ReadHeaderAsync(stream, cancellationToken);
-        if (headerData.Length == 0)
-        {
-            return null;
-        }
-        int offset = 0;
-
-        // Header type should be 0 for main header
-        if (headerData[offset++] != HeaderType)
-        {
-            return null;
-        }
-
-        // Header flags (2 bytes)
-        HeaderFlags = BitConverter.ToUInt16(headerData, offset);
-        offset += 2;
-
-        // Skip signature "**ACE**" (7 bytes)
-        if (!CheckMagicBytes(headerData, offset))
-        {
-            throw new InvalidDataException("Invalid ACE archive signature.");
-        }
-        offset += 7;
-
-        // ACE version (1 byte) - 10 for ACE 1.0, 20 for ACE 2.0
-        AceVersion = headerData[offset++];
-        ExtractVersion = headerData[offset++];
-
-        // Host OS (1 byte)
-        if (offset < headerData.Length)
-        {
-            var hostOsByte = headerData[offset++];
-            HostOS = hostOsByte <= 11 ? (HostOS)hostOsByte : HostOS.Unknown;
-        }
-        // Volume number (1 byte)
-        VolumeNumber = headerData[offset++];
-
-        // Creation date/time (4 bytes)
-        var dosDateTime = BitConverter.ToUInt32(headerData, offset);
-        DateTime = ConvertDosDateTime(dosDateTime);
-        offset += 4;
-
-        // Reserved fields (8 bytes)
-        if (offset + 8 <= headerData.Length)
-        {
-            offset += 8;
-        }
-
-        // Skip additional fields based on flags
-        // Handle comment if present
-        if ((HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.COMMENT) != 0)
-        {
-            if (offset + 2 <= headerData.Length)
-            {
-                ushort commentLength = BitConverter.ToUInt16(headerData, offset);
-                offset += 2 + commentLength;
-            }
-        }
-
-        return this;
-    }
-}

src/SharpCompress/Common/Ace/Headers/AceMainHeader.cs

@@ -2,8 +2,6 @@ using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common.Ace.Headers;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.Crypto;
@@ -13,7 +11,7 @@ namespace SharpCompress.Common.Ace.Headers
     /// <summary>
     /// ACE main archive header
     /// </summary>
-    public sealed partial class AceMainHeader : AceHeader
+    public sealed class AceMainHeader : AceHeader
     {
         public byte ExtractVersion { get; set; }
         public byte CreatorVersion { get; set; }
@@ -95,7 +93,5 @@ namespace SharpCompress.Common.Ace.Headers
 
             return this;
         }
-
-        // ReadAsync moved to AceMainHeader.Async.cs
     }
 }

src/SharpCompress/Common/Arj/Headers/ArjHeader.Async.cs

@@ -1,132 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Crypto;
-
-namespace SharpCompress.Common.Arj.Headers;
-
-public abstract partial class ArjHeader
-{
-    public abstract ValueTask<ArjHeader?> ReadAsync(
-        Stream reader,
-        CancellationToken cancellationToken = default
-    );
-
-    public async ValueTask<byte[]> ReadHeaderAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        // check for magic bytes
-        var magic = new byte[2];
-        if (await stream.ReadAsync(magic, 0, 2, cancellationToken) != 2)
-        {
-            return Array.Empty<byte>();
-        }
-
-        if (!CheckMagicBytes(magic))
-        {
-            throw new InvalidDataException("Not an ARJ file (wrong magic bytes)");
-        }
-
-        // read header_size
-        byte[] headerBytes = new byte[2];
-        await stream.ReadAsync(headerBytes, 0, 2, cancellationToken);
-        var headerSize = (ushort)(headerBytes[0] | headerBytes[1] << 8);
-        if (headerSize < 1)
-        {
-            return Array.Empty<byte>();
-        }
-
-        var body = new byte[headerSize];
-        var read = await stream.ReadAsync(body, 0, headerSize, cancellationToken);
-        if (read < headerSize)
-        {
-            return Array.Empty<byte>();
-        }
-
-        byte[] crc = new byte[4];
-        read = await stream.ReadAsync(crc, 0, 4, cancellationToken);
-        var checksum = Crc32Stream.Compute(body);
-        // Compute the hash value
-        if (checksum != BitConverter.ToUInt32(crc, 0))
-        {
-            throw new InvalidDataException("Header checksum is invalid");
-        }
-        return body;
-    }
-
-    protected async ValueTask<List<byte[]>> ReadExtendedHeadersAsync(
-        Stream reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        List<byte[]> extendedHeader = new List<byte[]>();
-        byte[] buffer = new byte[2];
-
-        while (true)
-        {
-            int bytesRead = await reader.ReadAsync(buffer, 0, 2, cancellationToken);
-            if (bytesRead < 2)
-            {
-                throw new EndOfStreamException(
-                    "Unexpected end of stream while reading extended header size."
-                );
-            }
-
-            var extHeaderSize = (ushort)(buffer[0] | (buffer[1] << 8));
-            if (extHeaderSize == 0)
-            {
-                return extendedHeader;
-            }
-
-            byte[] header = new byte[extHeaderSize];
-            bytesRead = await reader.ReadAsync(header, 0, extHeaderSize, cancellationToken);
-            if (bytesRead < extHeaderSize)
-            {
-                throw new EndOfStreamException(
-                    "Unexpected end of stream while reading extended header data."
-                );
-            }
-
-            byte[] crcextended = new byte[4];
-            bytesRead = await reader.ReadAsync(crcextended, 0, 4, cancellationToken);
-            if (bytesRead < 4)
-            {
-                throw new EndOfStreamException(
-                    "Unexpected end of stream while reading extended header CRC."
-                );
-            }
-
-            var checksum = Crc32Stream.Compute(header);
-            if (checksum != BitConverter.ToUInt32(crcextended, 0))
-            {
-                throw new InvalidDataException("Extended header checksum is invalid");
-            }
-
-            extendedHeader.Add(header);
-        }
-    }
-
-    /// <summary>
-    /// Asynchronously checks if the stream is an ARJ archive
-    /// </summary>
-    /// <param name="stream">The stream to read from</param>
-    /// <param name="cancellationToken">Cancellation token</param>
-    /// <returns>True if the stream is an ARJ archive, false otherwise</returns>
-    public static async ValueTask<bool> IsArchiveAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = new byte[2];
-        if (await stream.ReadAsync(bytes, 0, 2, cancellationToken) != 2)
-        {
-            return false;
-        }
-
-        return CheckMagicBytes(bytes);
-    }
-}

src/SharpCompress/Common/Arj/Headers/ArjHeader.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.Crypto;
@@ -16,7 +15,7 @@ namespace SharpCompress.Common.Arj.Headers
         LocalHeader,
     }
 
-    public abstract partial class ArjHeader
+    public abstract class ArjHeader
     {
         private const int FIRST_HDR_SIZE = 34;
         private const ushort ARJ_MAGIC = 0xEA60;
@@ -32,8 +31,6 @@ namespace SharpCompress.Common.Arj.Headers
 
         public abstract ArjHeader? Read(Stream reader);
 
-        // Async methods moved to ArjHeader.Async.cs
-
         public byte[] ReadHeader(Stream stream)
         {
             // check for magic bytes
@@ -75,8 +72,6 @@ namespace SharpCompress.Common.Arj.Headers
             return body;
         }
 
-        // ReadHeaderAsync moved to ArjHeader.Async.cs
-
         protected List<byte[]> ReadExtendedHeaders(Stream reader)
         {
             List<byte[]> extendedHeader = new List<byte[]>();

src/SharpCompress/Common/Arj/Headers/ArjLocalHeader.Async.cs

@@ -1,24 +0,0 @@
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common.Arj.Headers;
-
-public partial class ArjLocalHeader
-{
-    public override async ValueTask<ArjHeader?> ReadAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var body = await ReadHeaderAsync(stream, cancellationToken);
-        if (body.Length > 0)
-        {
-            await ReadExtendedHeadersAsync(stream, cancellationToken);
-            var header = LoadFrom(body);
-            header.DataStartPosition = stream.Position;
-            return header;
-        }
-        return null;
-    }
-}

src/SharpCompress/Common/Arj/Headers/ArjLocalHeader.cs

@@ -4,12 +4,11 @@ using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Arj.Headers
 {
-    public partial class ArjLocalHeader : ArjHeader
+    public class ArjLocalHeader : ArjHeader
     {
         public ArchiveEncoding ArchiveEncoding { get; }
         public long DataStartPosition { get; protected set; }
@@ -56,8 +55,6 @@ namespace SharpCompress.Common.Arj.Headers
             return null;
         }
 
-        // ReadAsync moved to ArjLocalHeader.Async.cs
-
         public ArjLocalHeader LoadFrom(byte[] headerBytes)
         {
             int offset = 0;

src/SharpCompress/Common/Arj/Headers/ArjMainHeader.Async.cs

@@ -1,18 +0,0 @@
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common.Arj.Headers;
-
-public partial class ArjMainHeader
-{
-    public override async ValueTask<ArjHeader?> ReadAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var body = await ReadHeaderAsync(stream, cancellationToken);
-        await ReadExtendedHeadersAsync(stream, cancellationToken);
-        return LoadFrom(body);
-    }
-}

src/SharpCompress/Common/Arj/Headers/ArjMainHeader.cs

@@ -1,14 +1,12 @@
 using System;
 using System.IO;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.Crypto;
 
 namespace SharpCompress.Common.Arj.Headers
 {
-    public partial class ArjMainHeader : ArjHeader
+    public class ArjMainHeader : ArjHeader
     {
         private const int FIRST_HDR_SIZE = 34;
         private const ushort ARJ_MAGIC = 0xEA60;
@@ -47,8 +45,6 @@ namespace SharpCompress.Common.Arj.Headers
             return LoadFrom(body);
         }
 
-        // ReadAsync moved to ArjMainHeader.Async.cs
-
         public ArjMainHeader LoadFrom(byte[] headerBytes)
         {
             var offset = 1;

src/SharpCompress/Common/AsyncBinaryReader.cs

@@ -16,11 +16,6 @@ namespace SharpCompress.Common
 
         public AsyncBinaryReader(Stream stream, bool leaveOpen = false, int bufferSize = 4096)
         {
-            if (!stream.CanRead)
-            {
-                throw new ArgumentException("Stream must be readable.");
-            }
-
             _originalStream = stream ?? throw new ArgumentNullException(nameof(stream));
             _leaveOpen = leaveOpen;
 
@@ -56,19 +51,11 @@ namespace SharpCompress.Common
             return BinaryPrimitives.ReadUInt64LittleEndian(_buffer);
         }
 
-        public async ValueTask ReadBytesAsync(
-            byte[] bytes,
-            int offset,
-            int count,
-            CancellationToken ct = default
-        )
+        public async ValueTask<byte[]> ReadBytesAsync(int count, CancellationToken ct = default)
         {
-            await _stream.ReadExactAsync(bytes, offset, count, ct).ConfigureAwait(false);
-        }
-
-        public async ValueTask SkipAsync(int count, CancellationToken ct = default)
-        {
-            await _stream.SkipAsync(count, ct).ConfigureAwait(false);
+            var result = new byte[count];
+            await _stream.ReadExactAsync(result, 0, count, ct).ConfigureAwait(false);
+            return result;
         }
 
         public void Dispose()
@@ -87,7 +74,7 @@ namespace SharpCompress.Common
             }
         }
 
-#if NET8_0_OR_GREATER
+#if NET6_0_OR_GREATER
         public async ValueTask DisposeAsync()
         {
             if (_disposed)

src/SharpCompress/Common/Constants.cs

@@ -1,12 +0,0 @@
-namespace SharpCompress.Common;
-
-public static class Constants
-{
-    /// <summary>
-    /// The default buffer size for stream operations, matching .NET's Stream.CopyTo default of 81920 bytes.
-    /// This can be modified globally at runtime.
-    /// </summary>
-    public static int BufferSize { get; set; } = 81920;
-
-    public static int RewindableBufferSize { get; set; } = 81920;
-}

src/SharpCompress/Common/EntryStream.Async.cs

@@ -1,84 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common;
-
-public partial class EntryStream
-{
-    /// <summary>
-    /// Asynchronously skip the rest of the entry stream.
-    /// </summary>
-    public async ValueTask SkipEntryAsync(CancellationToken cancellationToken = default)
-    {
-        await this.SkipAsync(cancellationToken).ConfigureAwait(false);
-        _completed = true;
-    }
-
-#if !LEGACY_DOTNET
-    public override async ValueTask DisposeAsync()
-    {
-        if (_isDisposed)
-        {
-            return;
-        }
-        _isDisposed = true;
-        if (!(_completed || _reader.Cancelled))
-        {
-            await SkipEntryAsync().ConfigureAwait(false);
-        }
-
-        //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised
-        if (_stream is IStreamStack ss)
-        {
-            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
-            {
-                await deflateStream.FlushAsync().ConfigureAwait(false);
-            }
-            else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
-            {
-                await lzmaStream.FlushAsync().ConfigureAwait(false);
-            }
-        }
-#if DEBUG_STREAMS
-        this.DebugDispose(typeof(EntryStream));
-#endif
-        await base.DisposeAsync().ConfigureAwait(false);
-        await _stream.DisposeAsync().ConfigureAwait(false);
-    }
-#endif
-
-    public override async Task<int> ReadAsync(
-        byte[] buffer,
-        int offset,
-        int count,
-        CancellationToken cancellationToken
-    )
-    {
-        var read = await _stream
-            .ReadAsync(buffer, offset, count, cancellationToken)
-            .ConfigureAwait(false);
-        if (read <= 0)
-        {
-            _completed = true;
-        }
-        return read;
-    }
-
-#if !LEGACY_DOTNET
-    public override async ValueTask<int> ReadAsync(
-        Memory<byte> buffer,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var read = await _stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
-        if (read <= 0)
-        {
-            _completed = true;
-        }
-        return read;
-    }
-#endif
-}

src/SharpCompress/Common/EntryStream.cs

@@ -8,7 +8,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Common;
 
-public partial class EntryStream : Stream, IStreamStack
+public class EntryStream : Stream, IStreamStack
 {
 #if DEBUG_STREAMS
     long IStreamStack.InstanceId { get; set; }
@@ -53,6 +53,15 @@ public partial class EntryStream : Stream, IStreamStack
         _completed = true;
     }
 
+    /// <summary>
+    /// Asynchronously skip the rest of the entry stream.
+    /// </summary>
+    public async ValueTask SkipEntryAsync(CancellationToken cancellationToken = default)
+    {
+        await this.SkipAsync(cancellationToken).ConfigureAwait(false);
+        _completed = true;
+    }
+
     protected override void Dispose(bool disposing)
     {
         if (_isDisposed)
@@ -84,6 +93,39 @@ public partial class EntryStream : Stream, IStreamStack
         _stream.Dispose();
     }
 
+#if !NETFRAMEWORK && !NETSTANDARD2_0
+    public override async ValueTask DisposeAsync()
+    {
+        if (_isDisposed)
+        {
+            return;
+        }
+        _isDisposed = true;
+        if (!(_completed || _reader.Cancelled))
+        {
+            await SkipEntryAsync().ConfigureAwait(false);
+        }
+
+        //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised
+        if (_stream is IStreamStack ss)
+        {
+            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
+            {
+                await deflateStream.FlushAsync().ConfigureAwait(false);
+            }
+            else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
+            {
+                await lzmaStream.FlushAsync().ConfigureAwait(false);
+            }
+        }
+#if DEBUG_STREAMS
+        this.DebugDispose(typeof(EntryStream));
+#endif
+        await base.DisposeAsync().ConfigureAwait(false);
+        await _stream.DisposeAsync().ConfigureAwait(false);
+    }
+#endif
+
     public override bool CanRead => true;
 
     public override bool CanSeek => false;
@@ -112,6 +154,38 @@ public partial class EntryStream : Stream, IStreamStack
         return read;
     }
 
+    public override async Task<int> ReadAsync(
+        byte[] buffer,
+        int offset,
+        int count,
+        CancellationToken cancellationToken
+    )
+    {
+        var read = await _stream
+            .ReadAsync(buffer, offset, count, cancellationToken)
+            .ConfigureAwait(false);
+        if (read <= 0)
+        {
+            _completed = true;
+        }
+        return read;
+    }
+
+#if !NETFRAMEWORK && !NETSTANDARD2_0
+    public override async ValueTask<int> ReadAsync(
+        Memory<byte> buffer,
+        CancellationToken cancellationToken = default
+    )
+    {
+        var read = await _stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
+        if (read <= 0)
+        {
+            _completed = true;
+        }
+        return read;
+    }
+#endif
+
     public override int ReadByte()
     {
         var value = _stream.ReadByte();

src/SharpCompress/Common/ExtractionMethods.Async.cs

@@ -1,116 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common;
-
-internal static partial class ExtractionMethods
-{
-    public static async ValueTask WriteEntryToDirectoryAsync(
-        IEntry entry,
-        string destinationDirectory,
-        ExtractionOptions? options,
-        Func<string, ExtractionOptions?, CancellationToken, ValueTask> writeAsync,
-        CancellationToken cancellationToken = default
-    )
-    {
-        string destinationFileName;
-        var fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
-
-        //check for trailing slash.
-        if (
-            fullDestinationDirectoryPath[fullDestinationDirectoryPath.Length - 1]
-            != Path.DirectorySeparatorChar
-        )
-        {
-            fullDestinationDirectoryPath += Path.DirectorySeparatorChar;
-        }
-
-        if (!Directory.Exists(fullDestinationDirectoryPath))
-        {
-            throw new ExtractionException(
-                $"Directory does not exist to extract to: {fullDestinationDirectoryPath}"
-            );
-        }
-
-        options ??= new ExtractionOptions() { Overwrite = true };
-
-        var file = Path.GetFileName(entry.Key.NotNull("Entry Key is null")).NotNull("File is null");
-        file = Utility.ReplaceInvalidFileNameChars(file);
-        if (options.ExtractFullPath)
-        {
-            var folder = Path.GetDirectoryName(entry.Key.NotNull("Entry Key is null"))
-                .NotNull("Directory is null");
-            var destdir = Path.GetFullPath(Path.Combine(fullDestinationDirectoryPath, folder));
-
-            if (!Directory.Exists(destdir))
-            {
-                if (!destdir.StartsWith(fullDestinationDirectoryPath, PathComparison))
-                {
-                    throw new ExtractionException(
-                        "Entry is trying to create a directory outside of the destination directory."
-                    );
-                }
-
-                Directory.CreateDirectory(destdir);
-            }
-            destinationFileName = Path.Combine(destdir, file);
-        }
-        else
-        {
-            destinationFileName = Path.Combine(fullDestinationDirectoryPath, file);
-        }
-
-        if (!entry.IsDirectory)
-        {
-            destinationFileName = Path.GetFullPath(destinationFileName);
-
-            if (!destinationFileName.StartsWith(fullDestinationDirectoryPath, PathComparison))
-            {
-                throw new ExtractionException(
-                    "Entry is trying to write a file outside of the destination directory."
-                );
-            }
-            await writeAsync(destinationFileName, options, cancellationToken).ConfigureAwait(false);
-        }
-        else if (options.ExtractFullPath && !Directory.Exists(destinationFileName))
-        {
-            Directory.CreateDirectory(destinationFileName);
-        }
-    }
-
-    public static async ValueTask WriteEntryToFileAsync(
-        IEntry entry,
-        string destinationFileName,
-        ExtractionOptions? options,
-        Func<string, FileMode, CancellationToken, ValueTask> openAndWriteAsync,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (entry.LinkTarget != null)
-        {
-            if (options?.WriteSymbolicLink is null)
-            {
-                throw new ExtractionException(
-                    "Entry is a symbolic link but ExtractionOptions.WriteSymbolicLink delegate is null"
-                );
-            }
-            options.WriteSymbolicLink(destinationFileName, entry.LinkTarget);
-        }
-        else
-        {
-            var fm = FileMode.Create;
-            options ??= new ExtractionOptions() { Overwrite = true };
-
-            if (!options.Overwrite)
-            {
-                fm = FileMode.CreateNew;
-            }
-
-            await openAndWriteAsync(destinationFileName, fm, cancellationToken)
-                .ConfigureAwait(false);
-            entry.PreserveExtractionOptions(destinationFileName, options);
-        }
-    }
-}

src/SharpCompress/Common/ExtractionMethods.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace SharpCompress.Common;
 
-internal static partial class ExtractionMethods
+internal static class ExtractionMethods
 {
     /// <summary>
     /// Gets the appropriate StringComparison for path checks based on the file system.
@@ -123,4 +123,111 @@ internal static partial class ExtractionMethods
             entry.PreserveExtractionOptions(destinationFileName, options);
         }
     }
+
+    public static async ValueTask WriteEntryToDirectoryAsync(
+        IEntry entry,
+        string destinationDirectory,
+        ExtractionOptions? options,
+        Func<string, ExtractionOptions?, CancellationToken, ValueTask> writeAsync,
+        CancellationToken cancellationToken = default
+    )
+    {
+        string destinationFileName;
+        var fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
+
+        //check for trailing slash.
+        if (
+            fullDestinationDirectoryPath[fullDestinationDirectoryPath.Length - 1]
+            != Path.DirectorySeparatorChar
+        )
+        {
+            fullDestinationDirectoryPath += Path.DirectorySeparatorChar;
+        }
+
+        if (!Directory.Exists(fullDestinationDirectoryPath))
+        {
+            throw new ExtractionException(
+                $"Directory does not exist to extract to: {fullDestinationDirectoryPath}"
+            );
+        }
+
+        options ??= new ExtractionOptions() { Overwrite = true };
+
+        var file = Path.GetFileName(entry.Key.NotNull("Entry Key is null")).NotNull("File is null");
+        file = Utility.ReplaceInvalidFileNameChars(file);
+        if (options.ExtractFullPath)
+        {
+            var folder = Path.GetDirectoryName(entry.Key.NotNull("Entry Key is null"))
+                .NotNull("Directory is null");
+            var destdir = Path.GetFullPath(Path.Combine(fullDestinationDirectoryPath, folder));
+
+            if (!Directory.Exists(destdir))
+            {
+                if (!destdir.StartsWith(fullDestinationDirectoryPath, PathComparison))
+                {
+                    throw new ExtractionException(
+                        "Entry is trying to create a directory outside of the destination directory."
+                    );
+                }
+
+                Directory.CreateDirectory(destdir);
+            }
+            destinationFileName = Path.Combine(destdir, file);
+        }
+        else
+        {
+            destinationFileName = Path.Combine(fullDestinationDirectoryPath, file);
+        }
+
+        if (!entry.IsDirectory)
+        {
+            destinationFileName = Path.GetFullPath(destinationFileName);
+
+            if (!destinationFileName.StartsWith(fullDestinationDirectoryPath, PathComparison))
+            {
+                throw new ExtractionException(
+                    "Entry is trying to write a file outside of the destination directory."
+                );
+            }
+            await writeAsync(destinationFileName, options, cancellationToken).ConfigureAwait(false);
+        }
+        else if (options.ExtractFullPath && !Directory.Exists(destinationFileName))
+        {
+            Directory.CreateDirectory(destinationFileName);
+        }
+    }
+
+    public static async ValueTask WriteEntryToFileAsync(
+        IEntry entry,
+        string destinationFileName,
+        ExtractionOptions? options,
+        Func<string, FileMode, CancellationToken, ValueTask> openAndWriteAsync,
+        CancellationToken cancellationToken = default
+    )
+    {
+        if (entry.LinkTarget != null)
+        {
+            if (options?.WriteSymbolicLink is null)
+            {
+                throw new ExtractionException(
+                    "Entry is a symbolic link but ExtractionOptions.WriteSymbolicLink delegate is null"
+                );
+            }
+            options.WriteSymbolicLink(destinationFileName, entry.LinkTarget);
+        }
+        else
+        {
+            var fm = FileMode.Create;
+            options ??= new ExtractionOptions() { Overwrite = true };
+
+            if (!options.Overwrite)
+            {
+                fm = FileMode.CreateNew;
+            }
+
+            await openAndWriteAsync(destinationFileName, fm, cancellationToken)
+                .ConfigureAwait(false);
+            entry.PreserveExtractionOptions(destinationFileName, options);
+        }
+    }
 }

src/SharpCompress/Common/GZip/GZipEntry.Async.cs

@@ -1,15 +0,0 @@
-using System.Collections.Generic;
-using System.IO;
-
-namespace SharpCompress.Common.GZip;
-
-public partial class GZipEntry
-{
-    internal static async IAsyncEnumerable<GZipEntry> GetEntriesAsync(
-        Stream stream,
-        OptionsBase options
-    )
-    {
-        yield return new GZipEntry(await GZipFilePart.CreateAsync(stream, options.ArchiveEncoding));
-    }
-}

src/SharpCompress/Common/GZip/GZipEntry.cs

@@ -4,7 +4,7 @@ using System.IO;
 
 namespace SharpCompress.Common.GZip;
 
-public partial class GZipEntry : Entry
+public class GZipEntry : Entry
 {
     private readonly GZipFilePart? _filePart;
 
@@ -40,8 +40,6 @@ public partial class GZipEntry : Entry
 
     internal static IEnumerable<GZipEntry> GetEntries(Stream stream, OptionsBase options)
     {
-        yield return new GZipEntry(GZipFilePart.Create(stream, options.ArchiveEncoding));
+        yield return new GZipEntry(new GZipFilePart(stream, options.ArchiveEncoding));
     }
-
-    // Async methods moved to GZipEntry.Async.cs
 }

src/SharpCompress/Common/GZip/GZipFilePart.Async.cs

@@ -1,133 +0,0 @@
-using System;
-using System.Buffers.Binary;
-using System.Collections.Generic;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Tar.Headers;
-using SharpCompress.Compressors.Deflate;
-
-namespace SharpCompress.Common.GZip;
-
-internal sealed partial class GZipFilePart
-{
-    internal static async ValueTask<GZipFilePart> CreateAsync(
-        Stream stream,
-        IArchiveEncoding archiveEncoding,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var part = new GZipFilePart(stream, archiveEncoding);
-
-        await part.ReadAndValidateGzipHeaderAsync(cancellationToken);
-        if (stream.CanSeek)
-        {
-            var position = stream.Position;
-            stream.Position = stream.Length - 8;
-            await part.ReadTrailerAsync(cancellationToken);
-            stream.Position = position;
-            part.EntryStartPosition = position;
-        }
-        else
-        {
-            // For non-seekable streams, we can't read the trailer or track position.
-            // Set to 0 since the stream will be read sequentially from its current position.
-            part.EntryStartPosition = 0;
-        }
-        return part;
-    }
-
-    private async ValueTask ReadTrailerAsync(CancellationToken cancellationToken = default)
-    {
-        // Read and potentially verify the GZIP trailer: CRC32 and  size mod 2^32
-        var trailer = new byte[8];
-        _ = await _stream.ReadFullyAsync(trailer, 0, 8, cancellationToken);
-
-        Crc = BinaryPrimitives.ReadUInt32LittleEndian(trailer);
-        UncompressedSize = BinaryPrimitives.ReadUInt32LittleEndian(trailer.AsSpan().Slice(4));
-    }
-
-    private async ValueTask ReadAndValidateGzipHeaderAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        // read the header on the first read
-        var header = new byte[10];
-        var n = await _stream.ReadAsync(header, 0, 10, cancellationToken);
-
-        // workitem 8501: handle edge case (decompress empty stream)
-        if (n == 0)
-        {
-            return;
-        }
-
-        if (n != 10)
-        {
-            throw new ZlibException("Not a valid GZIP stream.");
-        }
-
-        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-        {
-            throw new ZlibException("Bad GZIP header.");
-        }
-
-        var timet = BinaryPrimitives.ReadInt32LittleEndian(header.AsSpan().Slice(4));
-        DateModified = TarHeader.EPOCH.AddSeconds(timet);
-        if ((header[3] & 0x04) == 0x04)
-        {
-            // read and discard extra field
-            var lengthField = new byte[2];
-            _ = await _stream.ReadAsync(lengthField, 0, 2, cancellationToken);
-
-            var extraLength = (short)(lengthField[0] + (lengthField[1] * 256));
-            var extra = new byte[extraLength];
-
-            if (!await _stream.ReadFullyAsync(extra, cancellationToken))
-            {
-                throw new ZlibException("Unexpected end-of-file reading GZIP header.");
-            }
-        }
-        if ((header[3] & 0x08) == 0x08)
-        {
-            _name = await ReadZeroTerminatedStringAsync(_stream, cancellationToken);
-        }
-        if ((header[3] & 0x10) == 0x010)
-        {
-            await ReadZeroTerminatedStringAsync(_stream, cancellationToken);
-        }
-        if ((header[3] & 0x02) == 0x02)
-        {
-            var buf = new byte[1];
-            _ = await _stream.ReadAsync(buf, 0, 1, cancellationToken); // CRC16, ignore
-        }
-    }
-
-    private async ValueTask<string> ReadZeroTerminatedStringAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var buf1 = new byte[1];
-        var list = new List<byte>();
-        var done = false;
-        do
-        {
-            // workitem 7740
-            var n = await stream.ReadAsync(buf1, 0, 1, cancellationToken);
-            if (n != 1)
-            {
-                throw new ZlibException("Unexpected EOF reading GZIP header.");
-            }
-            if (buf1[0] == 0)
-            {
-                done = true;
-            }
-            else
-            {
-                list.Add(buf1[0]);
-            }
-        } while (!done);
-        var buffer = list.ToArray();
-        return ArchiveEncoding.Decode(buffer);
-    }
-}

src/SharpCompress/Common/GZip/GZipFilePart.cs

@@ -8,37 +8,33 @@ using SharpCompress.Compressors.Deflate;
 
 namespace SharpCompress.Common.GZip;
 
-internal sealed partial class GZipFilePart : FilePart
+internal sealed class GZipFilePart : FilePart
 {
     private string? _name;
     private readonly Stream _stream;
 
-    internal static GZipFilePart Create(Stream stream, IArchiveEncoding archiveEncoding)
+    internal GZipFilePart(Stream stream, IArchiveEncoding archiveEncoding)
+        : base(archiveEncoding)
     {
-        var part = new GZipFilePart(stream, archiveEncoding);
-
-        part.ReadAndValidateGzipHeader();
+        _stream = stream;
+        ReadAndValidateGzipHeader();
         if (stream.CanSeek)
         {
             var position = stream.Position;
             stream.Position = stream.Length - 8;
-            part.ReadTrailer();
+            ReadTrailer();
             stream.Position = position;
-            part.EntryStartPosition = position;
+            EntryStartPosition = position;
         }
         else
         {
             // For non-seekable streams, we can't read the trailer or track position.
             // Set to 0 since the stream will be read sequentially from its current position.
-            part.EntryStartPosition = 0;
+            EntryStartPosition = 0;
         }
-        return part;
     }
 
-    private GZipFilePart(Stream stream, IArchiveEncoding archiveEncoding)
-        : base(archiveEncoding) => _stream = stream;
-
-    internal long EntryStartPosition { get; private set; }
+    internal long EntryStartPosition { get; }
 
     internal DateTime? DateModified { get; private set; }
     internal uint? Crc { get; private set; }
@@ -47,12 +43,7 @@ internal sealed partial class GZipFilePart : FilePart
     internal override string? FilePartName => _name;
 
     internal override Stream GetCompressedStream() =>
-        new DeflateStream(
-            _stream,
-            CompressionMode.Decompress,
-            CompressionLevel.Default,
-            leaveOpen: true
-        );
+        new DeflateStream(_stream, CompressionMode.Decompress, CompressionLevel.Default);
 
     internal override Stream GetRawStream() => _stream;
 
@@ -60,7 +51,7 @@ internal sealed partial class GZipFilePart : FilePart
     {
         // Read and potentially verify the GZIP trailer: CRC32 and  size mod 2^32
         Span<byte> trailer = stackalloc byte[8];
-        _stream.ReadFully(trailer);
+        var n = _stream.Read(trailer);
 
         Crc = BinaryPrimitives.ReadUInt32LittleEndian(trailer);
         UncompressedSize = BinaryPrimitives.ReadUInt32LittleEndian(trailer.Slice(4));

src/SharpCompress/Common/IVolume.cs

@@ -2,7 +2,7 @@ using System;
 
 namespace SharpCompress.Common;
 
-public interface IVolume : IDisposable, IAsyncDisposable
+public interface IVolume : IDisposable
 {
     int Index { get; }
 

src/SharpCompress/Common/Rar/AsyncMarkingBinaryReader.cs

@@ -1,189 +0,0 @@
-using System;
-using System.Buffers.Binary;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-
-namespace SharpCompress.Common.Rar;
-
-internal class AsyncMarkingBinaryReader
-{
-    private readonly AsyncBinaryReader _reader;
-
-    public AsyncMarkingBinaryReader(Stream stream)
-    {
-        _reader = new AsyncBinaryReader(stream, leaveOpen: true);
-    }
-
-    public Stream BaseStream => _reader.BaseStream;
-
-    public virtual long CurrentReadByteCount { get; protected set; }
-
-    public virtual void Mark() => CurrentReadByteCount = 0;
-
-    public virtual async ValueTask<bool> ReadBooleanAsync(
-        CancellationToken cancellationToken = default
-    ) => await ReadByteAsync(cancellationToken).ConfigureAwait(false) != 0;
-
-    public virtual async ValueTask<byte> ReadByteAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        CurrentReadByteCount++;
-        return await _reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-    }
-
-    public virtual async ValueTask<byte[]> ReadBytesAsync(
-        int count,
-        CancellationToken cancellationToken = default
-    )
-    {
-        CurrentReadByteCount += count;
-        var bytes = new byte[count];
-        await _reader.ReadBytesAsync(bytes, 0, count, cancellationToken).ConfigureAwait(false);
-        return bytes;
-    }
-
-    public async ValueTask<ushort> ReadUInt16Async(CancellationToken cancellationToken = default)
-    {
-        var bytes = await ReadBytesAsync(2, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadUInt16LittleEndian(bytes);
-    }
-
-    public async ValueTask<uint> ReadUInt32Async(CancellationToken cancellationToken = default)
-    {
-        var bytes = await ReadBytesAsync(4, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadUInt32LittleEndian(bytes);
-    }
-
-    public virtual async ValueTask<ulong> ReadUInt64Async(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = await ReadBytesAsync(8, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadUInt64LittleEndian(bytes);
-    }
-
-    public virtual async ValueTask<short> ReadInt16Async(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = await ReadBytesAsync(2, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadInt16LittleEndian(bytes);
-    }
-
-    public virtual async ValueTask<int> ReadInt32Async(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = await ReadBytesAsync(4, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadInt32LittleEndian(bytes);
-    }
-
-    public virtual async ValueTask<long> ReadInt64Async(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = await ReadBytesAsync(8, cancellationToken).ConfigureAwait(false);
-        return BinaryPrimitives.ReadInt64LittleEndian(bytes);
-    }
-
-    public async ValueTask<ulong> ReadRarVIntAsync(
-        CancellationToken cancellationToken = default,
-        int maxBytes = 10
-    ) => await DoReadRarVIntAsync((maxBytes - 1) * 7, cancellationToken).ConfigureAwait(false);
-
-    private async ValueTask<ulong> DoReadRarVIntAsync(
-        int maxShift,
-        CancellationToken cancellationToken
-    )
-    {
-        var shift = 0;
-        ulong result = 0;
-        do
-        {
-            var b0 = await ReadByteAsync(cancellationToken).ConfigureAwait(false);
-            var b1 = ((uint)b0) & 0x7f;
-            ulong n = b1;
-            var shifted = n << shift;
-            if (n != shifted >> shift)
-            {
-                // overflow
-                break;
-            }
-            result |= shifted;
-            if (b0 == b1)
-            {
-                return result;
-            }
-            shift += 7;
-        } while (shift <= maxShift);
-
-        throw new FormatException("malformed vint");
-    }
-
-    public async ValueTask<uint> ReadRarVIntUInt32Async(
-        int maxBytes = 5,
-        CancellationToken cancellationToken = default
-    ) =>
-        // hopefully this gets inlined
-        await DoReadRarVIntUInt32Async((maxBytes - 1) * 7, cancellationToken).ConfigureAwait(false);
-
-    public async ValueTask<ushort> ReadRarVIntUInt16Async(
-        int maxBytes = 3,
-        CancellationToken cancellationToken = default
-    ) =>
-        // hopefully this gets inlined
-        checked(
-            (ushort)
-                await DoReadRarVIntUInt32Async((maxBytes - 1) * 7, cancellationToken)
-                    .ConfigureAwait(false)
-        );
-
-    public async ValueTask<byte> ReadRarVIntByteAsync(
-        int maxBytes = 2,
-        CancellationToken cancellationToken = default
-    ) =>
-        // hopefully this gets inlined
-        checked(
-            (byte)
-                await DoReadRarVIntUInt32Async((maxBytes - 1) * 7, cancellationToken)
-                    .ConfigureAwait(false)
-        );
-
-    public async ValueTask SkipAsync(int count, CancellationToken cancellationToken = default)
-    {
-        CurrentReadByteCount += count;
-        await _reader.SkipAsync(count, cancellationToken).ConfigureAwait(false);
-    }
-
-    private async ValueTask<uint> DoReadRarVIntUInt32Async(
-        int maxShift,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var shift = 0;
-        uint result = 0;
-        do
-        {
-            var b0 = await ReadByteAsync(cancellationToken).ConfigureAwait(false);
-            var b1 = ((uint)b0) & 0x7f;
-            var n = b1;
-            var shifted = n << shift;
-            if (n != shifted >> shift)
-            {
-                // overflow
-                break;
-            }
-            result |= shifted;
-            if (b0 == b1)
-            {
-                return result;
-            }
-            shift += 7;
-        } while (shift <= maxShift);
-
-        throw new FormatException("malformed vint");
-    }
-}

src/SharpCompress/Common/Rar/AsyncRarCrcBinaryReader.cs

@@ -1,45 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Compressors.Rar;
-
-namespace SharpCompress.Common.Rar;
-
-internal class AsyncRarCrcBinaryReader(Stream stream) : AsyncMarkingBinaryReader(stream)
-{
-    private uint _currentCrc;
-
-    public uint GetCrc32() => ~_currentCrc;
-
-    public void ResetCrc() => _currentCrc = 0xffffffff;
-
-    protected void UpdateCrc(byte b) => _currentCrc = RarCRC.CheckCrc(_currentCrc, b);
-
-    protected async ValueTask<byte[]> ReadBytesNoCrcAsync(
-        int count,
-        CancellationToken cancellationToken = default
-    )
-    {
-        return await base.ReadBytesAsync(count, cancellationToken).ConfigureAwait(false);
-    }
-
-    public override async ValueTask<byte> ReadByteAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var b = await base.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-        _currentCrc = RarCRC.CheckCrc(_currentCrc, b);
-        return b;
-    }
-
-    public override async ValueTask<byte[]> ReadBytesAsync(
-        int count,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var result = await base.ReadBytesAsync(count, cancellationToken).ConfigureAwait(false);
-        _currentCrc = RarCRC.CheckCrc(_currentCrc, result, 0, result.Length);
-        return result;
-    }
-}

src/SharpCompress/Common/Rar/AsyncRarCryptoBinaryReader.cs

@@ -1,109 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar.Headers;
-using SharpCompress.Crypto;
-
-namespace SharpCompress.Common.Rar;
-
-internal sealed class AsyncRarCryptoBinaryReader : AsyncRarCrcBinaryReader
-{
-    private BlockTransformer _rijndael = default!;
-    private readonly Queue<byte> _data = new();
-    private long _readCount;
-
-    private AsyncRarCryptoBinaryReader(Stream stream)
-        : base(stream) { }
-
-    public static async ValueTask<AsyncRarCryptoBinaryReader> Create(
-        Stream stream,
-        ICryptKey cryptKey,
-        byte[]? salt = null
-    )
-    {
-        var binary = new AsyncRarCryptoBinaryReader(stream);
-        if (salt == null)
-        {
-            salt = await binary.ReadBytesAsyncBase(EncryptionConstV5.SIZE_SALT30);
-            binary._readCount += EncryptionConstV5.SIZE_SALT30;
-        }
-        binary._rijndael = new BlockTransformer(cryptKey.Transformer(salt));
-        return binary;
-    }
-
-    public override long CurrentReadByteCount
-    {
-        get => _readCount;
-        protected set
-        {
-            // ignore
-        }
-    }
-
-    public override void Mark() => _readCount = 0;
-
-    public override async ValueTask<byte> ReadByteAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        var bytes = await ReadAndDecryptBytesAsync(1, cancellationToken).ConfigureAwait(false);
-        return bytes[0];
-    }
-
-    private ValueTask<byte[]> ReadBytesAsyncBase(int count) => base.ReadBytesAsync(count);
-
-    public override async ValueTask<byte[]> ReadBytesAsync(
-        int count,
-        CancellationToken cancellationToken = default
-    )
-    {
-        return await ReadAndDecryptBytesAsync(count, cancellationToken).ConfigureAwait(false);
-    }
-
-    private async ValueTask<byte[]> ReadAndDecryptBytesAsync(
-        int count,
-        CancellationToken cancellationToken
-    )
-    {
-        var queueSize = _data.Count;
-        var sizeToRead = count - queueSize;
-
-        if (sizeToRead > 0)
-        {
-            var alignedSize = sizeToRead + ((~sizeToRead + 1) & 0xf);
-            for (var i = 0; i < alignedSize / 16; i++)
-            {
-                var cipherText = await ReadBytesNoCrcAsync(16, cancellationToken)
-                    .ConfigureAwait(false);
-                var readBytes = _rijndael.ProcessBlock(cipherText);
-                foreach (var readByte in readBytes)
-                {
-                    _data.Enqueue(readByte);
-                }
-            }
-        }
-
-        var decryptedBytes = new byte[count];
-
-        for (var i = 0; i < count; i++)
-        {
-            var b = _data.Dequeue();
-            decryptedBytes[i] = b;
-            UpdateCrc(b);
-        }
-
-        _readCount += count;
-        return decryptedBytes;
-    }
-
-    public void ClearQueue() => _data.Clear();
-
-    public void SkipQueue()
-    {
-        var position = BaseStream.Position;
-        BaseStream.Position = position + _data.Count;
-        ClearQueue();
-    }
-}

src/SharpCompress/Common/Rar/Headers/AVHeader.cs

@@ -4,14 +4,13 @@ namespace SharpCompress.Common.Rar.Headers;
 
 internal class AvHeader : RarHeader
 {
-    public static AvHeader Create(RarHeader header, RarCrcBinaryReader reader)
+    public AvHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.Av)
     {
-        var c = CreateChild<AvHeader>(header, reader, HeaderType.Av);
-        if (c.IsRar5)
+        if (IsRar5)
         {
             throw new InvalidFormatException("unexpected rar5 record");
         }
-        return c;
     }
 
     protected override void ReadFinish(MarkingBinaryReader reader)

src/SharpCompress/Common/Rar/Headers/ArchiveCryptHeader.Async.cs

@@ -1,32 +0,0 @@
-#nullable disable
-
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal sealed partial class ArchiveCryptHeader
-{
-    public static async ValueTask<ArchiveCryptHeader> CreateAsync(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        CancellationToken cancellationToken = default
-    ) =>
-        await CreateChildAsync<ArchiveCryptHeader>(
-                header,
-                reader,
-                HeaderType.Crypt,
-                cancellationToken
-            )
-            .ConfigureAwait(false);
-
-    protected sealed override async ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        CryptInfo = await Rar5CryptoInfo.CreateAsync(reader, false);
-    }
-}

src/SharpCompress/Common/Rar/Headers/ArchiveCryptHeader.cs

@@ -1,17 +1,16 @@
 #nullable disable
 
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal sealed partial class ArchiveCryptHeader : RarHeader
+internal class ArchiveCryptHeader : RarHeader
 {
-    public static ArchiveCryptHeader Create(RarHeader header, RarCrcBinaryReader reader) =>
-        CreateChild<ArchiveCryptHeader>(header, reader, HeaderType.Crypt);
+    public ArchiveCryptHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.Crypt) { }
 
-    public Rar5CryptoInfo CryptInfo = default!;
+    public Rar5CryptoInfo CryptInfo = new();
 
-    protected sealed override void ReadFinish(MarkingBinaryReader reader) =>
-        CryptInfo = Rar5CryptoInfo.Create(reader, false);
+    protected override void ReadFinish(MarkingBinaryReader reader) =>
+        CryptInfo = new Rar5CryptoInfo(reader, false);
 }

src/SharpCompress/Common/Rar/Headers/ArchiveHeader.Async.cs

@@ -1,53 +0,0 @@
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal sealed partial class ArchiveHeader
-{
-    public static async ValueTask<ArchiveHeader> CreateAsync(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        CancellationToken cancellationToken = default
-    ) =>
-        await CreateChildAsync<ArchiveHeader>(header, reader, HeaderType.Archive, cancellationToken)
-            .ConfigureAwait(false);
-
-    protected sealed override async ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (IsRar5)
-        {
-            Flags = await reader
-                .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                .ConfigureAwait(false);
-            if (HasFlag(ArchiveFlagsV5.HAS_VOLUME_NUMBER))
-            {
-                VolumeNumber = (int)
-                    await reader
-                        .ReadRarVIntUInt32Async(cancellationToken: cancellationToken)
-                        .ConfigureAwait(false);
-            }
-            // later: we may have a locator record if we need it
-            //if (ExtraSize != 0) {
-            //    ReadLocator(reader);
-            //}
-        }
-        else
-        {
-            Flags = HeaderFlags;
-            HighPosAv = await reader.ReadInt16Async(cancellationToken).ConfigureAwait(false);
-            PosAv = await reader.ReadInt32Async(cancellationToken).ConfigureAwait(false);
-            if (HasFlag(ArchiveFlagsV4.ENCRYPT_VER))
-            {
-                EncryptionVersion = await reader
-                    .ReadByteAsync(cancellationToken)
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-}

src/SharpCompress/Common/Rar/Headers/ArchiveHeader.cs

@@ -1,14 +1,13 @@
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal sealed partial class ArchiveHeader : RarHeader
+internal sealed class ArchiveHeader : RarHeader
 {
-    public static ArchiveHeader Create(RarHeader header, RarCrcBinaryReader reader) =>
-        CreateChild<ArchiveHeader>(header, reader, HeaderType.Archive);
+    public ArchiveHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.Archive) { }
 
-    protected sealed override void ReadFinish(MarkingBinaryReader reader)
+    protected override void ReadFinish(MarkingBinaryReader reader)
     {
         if (IsRar5)
         {

src/SharpCompress/Common/Rar/Headers/CommentHeader.cs

@@ -4,14 +4,13 @@ namespace SharpCompress.Common.Rar.Headers;
 
 internal class CommentHeader : RarHeader
 {
-    public static CommentHeader Create(RarHeader header, RarCrcBinaryReader reader)
+    protected CommentHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.Comment)
     {
-        var c = CreateChild<CommentHeader>(header, reader, HeaderType.Comment);
-        if (c.IsRar5)
+        if (IsRar5)
         {
             throw new InvalidFormatException("unexpected rar5 record");
         }
-        return c;
     }
 
     protected override void ReadFinish(MarkingBinaryReader reader)

src/SharpCompress/Common/Rar/Headers/EndArchiveHeader.Async.cs

@@ -1,47 +0,0 @@
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal sealed partial class EndArchiveHeader
-{
-    public static async ValueTask<EndArchiveHeader> CreateAsync(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        CancellationToken cancellationToken = default
-    ) =>
-        await CreateChildAsync<EndArchiveHeader>(
-                header,
-                reader,
-                HeaderType.EndArchive,
-                cancellationToken
-            )
-            .ConfigureAwait(false);
-
-    protected sealed override async ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (IsRar5)
-        {
-            Flags = await reader
-                .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                .ConfigureAwait(false);
-        }
-        else
-        {
-            Flags = HeaderFlags;
-            if (HasFlag(EndArchiveFlagsV4.DATA_CRC))
-            {
-                ArchiveCrc = await reader.ReadInt32Async(cancellationToken).ConfigureAwait(false);
-            }
-            if (HasFlag(EndArchiveFlagsV4.VOLUME_NUMBER))
-            {
-                VolumeNumber = await reader.ReadInt16Async(cancellationToken).ConfigureAwait(false);
-            }
-        }
-    }
-}

src/SharpCompress/Common/Rar/Headers/EndArchiveHeader.cs

@@ -1,14 +1,13 @@
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal sealed partial class EndArchiveHeader : RarHeader
+internal class EndArchiveHeader : RarHeader
 {
-    public static EndArchiveHeader Create(RarHeader header, RarCrcBinaryReader reader) =>
-        CreateChild<EndArchiveHeader>(header, reader, HeaderType.EndArchive);
+    public EndArchiveHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.EndArchive) { }
 
-    protected sealed override void ReadFinish(MarkingBinaryReader reader)
+    protected override void ReadFinish(MarkingBinaryReader reader)
     {
         if (IsRar5)
         {

src/SharpCompress/Common/Rar/Headers/FileHeader.Async.cs

@@ -1,443 +0,0 @@
-using System;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-#if !Rar2017_64bit
-using size_t = System.UInt32;
-#else
-using nint = System.Int64;
-using nuint = System.UInt64;
-using size_t = System.UInt64;
-#endif
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal partial class FileHeader
-{
-    public static async ValueTask<FileHeader> CreateAsync(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        HeaderType headerType,
-        CancellationToken cancellationToken = default
-    ) =>
-        await CreateChildAsync<FileHeader>(header, reader, headerType, cancellationToken)
-            .ConfigureAwait(false);
-
-    protected override async ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken
-    )
-    {
-        if (IsRar5)
-        {
-            await ReadFromReaderV5Async(reader, cancellationToken).ConfigureAwait(false);
-        }
-        else
-        {
-            await ReadFromReaderV4Async(reader, cancellationToken).ConfigureAwait(false);
-        }
-    }
-
-    private async ValueTask ReadFromReaderV5Async(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken
-    )
-    {
-        Flags = await reader
-            .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-            .ConfigureAwait(false);
-
-        var lvalue = checked(
-            (long)
-                await reader
-                    .ReadRarVIntAsync(cancellationToken: cancellationToken)
-                    .ConfigureAwait(false)
-        );
-
-        UncompressedSize = HasFlag(FileFlagsV5.UNPACKED_SIZE_UNKNOWN) ? long.MaxValue : lvalue;
-
-        FileAttributes = await reader
-            .ReadRarVIntUInt32Async(cancellationToken: cancellationToken)
-            .ConfigureAwait(false);
-
-        if (HasFlag(FileFlagsV5.HAS_MOD_TIME))
-        {
-            FileLastModifiedTime = Utility.UnixTimeToDateTime(
-                await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false)
-            );
-        }
-
-        if (HasFlag(FileFlagsV5.HAS_CRC32))
-        {
-            FileCrc = await reader.ReadBytesAsync(4, cancellationToken).ConfigureAwait(false);
-        }
-
-        var compressionInfo = await reader
-            .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-            .ConfigureAwait(false);
-
-        CompressionAlgorithm = (byte)((compressionInfo & 0x3f) + 50);
-        IsSolid = (compressionInfo & 0x40) == 0x40;
-        CompressionMethod = (byte)((compressionInfo >> 7) & 0x7);
-        WindowSize = IsDirectory ? 0 : ((size_t)0x20000) << ((compressionInfo >> 10) & 0xf);
-
-        HostOs = await reader
-            .ReadRarVIntByteAsync(cancellationToken: cancellationToken)
-            .ConfigureAwait(false);
-
-        var nameSize = await reader
-            .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-            .ConfigureAwait(false);
-
-        var b = await reader.ReadBytesAsync(nameSize, cancellationToken).ConfigureAwait(false);
-        FileName = ConvertPathV5(Encoding.UTF8.GetString(b, 0, b.Length));
-
-        if (ExtraSize != (uint)RemainingHeaderBytesAsync(reader))
-        {
-            throw new InvalidFormatException("rar5 header size / extra size inconsistency");
-        }
-
-        const ushort FHEXTRA_CRYPT = 0x01;
-        const ushort FHEXTRA_HASH = 0x02;
-        const ushort FHEXTRA_HTIME = 0x03;
-        const ushort FHEXTRA_REDIR = 0x05;
-
-        while (reader.CurrentReadByteCount < HeaderSize)
-        {
-            var size = await reader
-                .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                .ConfigureAwait(false);
-            var n = HeaderSize - reader.CurrentReadByteCount;
-            var type = await reader
-                .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                .ConfigureAwait(false);
-            switch (type)
-            {
-                case FHEXTRA_CRYPT:
-                    {
-                        Rar5CryptoInfo = await Rar5CryptoInfo
-                            .CreateAsync(reader, true)
-                            .ConfigureAwait(false);
-                        if (Rar5CryptoInfo.PswCheck.All(singleByte => singleByte == 0))
-                        {
-                            Rar5CryptoInfo = null;
-                        }
-                    }
-                    break;
-                case FHEXTRA_HASH:
-                    {
-                        const uint FHEXTRA_HASH_BLAKE2 = 0x0;
-                        const int BLAKE2_DIGEST_SIZE = 0x20;
-                        if (
-                            await reader
-                                .ReadRarVIntUInt32Async(cancellationToken: cancellationToken)
-                                .ConfigureAwait(false) == FHEXTRA_HASH_BLAKE2
-                        )
-                        {
-                            _hash = await reader
-                                .ReadBytesAsync(BLAKE2_DIGEST_SIZE, cancellationToken)
-                                .ConfigureAwait(false);
-                        }
-                    }
-                    break;
-                case FHEXTRA_HTIME:
-                    {
-                        var flags = await reader
-                            .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                            .ConfigureAwait(false);
-                        var isWindowsTime = (flags & 1) == 0;
-                        if ((flags & 0x2) == 0x2)
-                        {
-                            FileLastModifiedTime = await ReadExtendedTimeV5Async(
-                                    reader,
-                                    isWindowsTime,
-                                    cancellationToken
-                                )
-                                .ConfigureAwait(false);
-                        }
-                        if ((flags & 0x4) == 0x4)
-                        {
-                            FileCreatedTime = await ReadExtendedTimeV5Async(
-                                    reader,
-                                    isWindowsTime,
-                                    cancellationToken
-                                )
-                                .ConfigureAwait(false);
-                        }
-                        if ((flags & 0x8) == 0x8)
-                        {
-                            FileLastAccessedTime = await ReadExtendedTimeV5Async(
-                                    reader,
-                                    isWindowsTime,
-                                    cancellationToken
-                                )
-                                .ConfigureAwait(false);
-                        }
-                    }
-                    break;
-                case FHEXTRA_REDIR:
-                    {
-                        RedirType = await reader
-                            .ReadRarVIntByteAsync(cancellationToken: cancellationToken)
-                            .ConfigureAwait(false);
-                        RedirFlags = await reader
-                            .ReadRarVIntByteAsync(cancellationToken: cancellationToken)
-                            .ConfigureAwait(false);
-                        var nn = await reader
-                            .ReadRarVIntUInt16Async(cancellationToken: cancellationToken)
-                            .ConfigureAwait(false);
-                        var bb = await reader
-                            .ReadBytesAsync(nn, cancellationToken)
-                            .ConfigureAwait(false);
-                        RedirTargetName = ConvertPathV5(Encoding.UTF8.GetString(bb, 0, bb.Length));
-                    }
-                    break;
-                default:
-                    break;
-            }
-            var did = (int)(n - (HeaderSize - reader.CurrentReadByteCount));
-            var drain = size - did;
-            if (drain > 0)
-            {
-                await reader.ReadBytesAsync(drain, cancellationToken).ConfigureAwait(false);
-            }
-        }
-
-        if (AdditionalDataSize != 0)
-        {
-            CompressedSize = AdditionalDataSize;
-        }
-    }
-
-    private async ValueTask ReadFromReaderV4Async(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken
-    )
-    {
-        Flags = HeaderFlags;
-        IsSolid = HasFlag(FileFlagsV4.SOLID);
-        WindowSize = IsDirectory
-            ? 0U
-            : ((size_t)0x10000) << ((Flags & FileFlagsV4.WINDOW_MASK) >> 5);
-
-        var lowUncompressedSize = await reader
-            .ReadUInt32Async(cancellationToken)
-            .ConfigureAwait(false);
-
-        HostOs = await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-
-        FileCrc = await reader.ReadBytesAsync(4, cancellationToken).ConfigureAwait(false);
-
-        FileLastModifiedTime = Utility.DosDateToDateTime(
-            await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false)
-        );
-
-        CompressionAlgorithm = await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-        CompressionMethod = (byte)(
-            (await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false)) - 0x30
-        );
-
-        var nameSize = await reader.ReadInt16Async(cancellationToken).ConfigureAwait(false);
-
-        FileAttributes = await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false);
-
-        uint highCompressedSize = 0;
-        uint highUncompressedkSize = 0;
-        if (HasFlag(FileFlagsV4.LARGE))
-        {
-            highCompressedSize = await reader
-                .ReadUInt32Async(cancellationToken)
-                .ConfigureAwait(false);
-            highUncompressedkSize = await reader
-                .ReadUInt32Async(cancellationToken)
-                .ConfigureAwait(false);
-        }
-        else
-        {
-            if (lowUncompressedSize == 0xffffffff)
-            {
-                lowUncompressedSize = 0xffffffff;
-                highUncompressedkSize = int.MaxValue;
-            }
-        }
-        CompressedSize = UInt32To64(highCompressedSize, checked((uint)AdditionalDataSize));
-        UncompressedSize = UInt32To64(highUncompressedkSize, lowUncompressedSize);
-
-        nameSize = nameSize > 4 * 1024 ? (short)(4 * 1024) : nameSize;
-
-        var fileNameBytes = await reader
-            .ReadBytesAsync(nameSize, cancellationToken)
-            .ConfigureAwait(false);
-
-        const int newLhdSize = 32;
-
-        switch (HeaderCode)
-        {
-            case HeaderCodeV.RAR4_FILE_HEADER:
-                {
-                    if (HasFlag(FileFlagsV4.UNICODE))
-                    {
-                        var length = 0;
-                        while (length < fileNameBytes.Length && fileNameBytes[length] != 0)
-                        {
-                            length++;
-                        }
-                        if (length != nameSize)
-                        {
-                            length++;
-                            FileName = FileNameDecoder.Decode(fileNameBytes, length);
-                        }
-                        else
-                        {
-                            FileName = ArchiveEncoding.Decode(fileNameBytes);
-                        }
-                    }
-                    else
-                    {
-                        FileName = ArchiveEncoding.Decode(fileNameBytes);
-                    }
-                    FileName = ConvertPathV4(FileName);
-                }
-                break;
-            case HeaderCodeV.RAR4_NEW_SUB_HEADER:
-                {
-                    var datasize = HeaderSize - newLhdSize - nameSize;
-                    if (HasFlag(FileFlagsV4.SALT))
-                    {
-                        datasize -= EncryptionConstV5.SIZE_SALT30;
-                    }
-                    if (datasize > 0)
-                    {
-                        SubData = await reader
-                            .ReadBytesAsync(datasize, cancellationToken)
-                            .ConfigureAwait(false);
-                    }
-
-                    if (NewSubHeaderType.SUBHEAD_TYPE_RR.Equals(fileNameBytes.Take(4).ToArray()))
-                    {
-                        if (SubData is null)
-                        {
-                            throw new InvalidFormatException();
-                        }
-                        RecoverySectors =
-                            SubData[8]
-                            + (SubData[9] << 8)
-                            + (SubData[10] << 16)
-                            + (SubData[11] << 24);
-                    }
-                }
-                break;
-        }
-
-        if (HasFlag(FileFlagsV4.SALT))
-        {
-            R4Salt = await reader.ReadBytesAsync(EncryptionConstV5.SIZE_SALT30, cancellationToken);
-        }
-        if (HasFlag(FileFlagsV4.EXT_TIME))
-        {
-            if (reader.CurrentReadByteCount >= 2)
-            {
-                var extendedFlags = await reader
-                    .ReadUInt16Async(cancellationToken)
-                    .ConfigureAwait(false);
-                if (FileLastModifiedTime is not null)
-                {
-                    FileLastModifiedTime = await ProcessExtendedTimeV4Async(
-                            extendedFlags,
-                            FileLastModifiedTime,
-                            reader,
-                            0,
-                            cancellationToken
-                        )
-                        .ConfigureAwait(false);
-                }
-
-                FileCreatedTime = await ProcessExtendedTimeV4Async(
-                        extendedFlags,
-                        null,
-                        reader,
-                        1,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-                FileLastAccessedTime = await ProcessExtendedTimeV4Async(
-                        extendedFlags,
-                        null,
-                        reader,
-                        2,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-                FileArchivedTime = await ProcessExtendedTimeV4Async(
-                        extendedFlags,
-                        null,
-                        reader,
-                        3,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-
-    private static async ValueTask<DateTime> ReadExtendedTimeV5Async(
-        AsyncMarkingBinaryReader reader,
-        bool isWindowsTime,
-        CancellationToken cancellationToken
-    )
-    {
-        if (isWindowsTime)
-        {
-            return DateTime.FromFileTime(
-                await reader.ReadInt64Async(cancellationToken).ConfigureAwait(false)
-            );
-        }
-        else
-        {
-            return Utility.UnixTimeToDateTime(
-                await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false)
-            );
-        }
-    }
-
-    private static async ValueTask<DateTime?> ProcessExtendedTimeV4Async(
-        ushort extendedFlags,
-        DateTime? time,
-        AsyncMarkingBinaryReader reader,
-        int i,
-        CancellationToken cancellationToken
-    )
-    {
-        var rmode = (uint)extendedFlags >> ((3 - i) * 4);
-        if ((rmode & 8) == 0)
-        {
-            return null;
-        }
-        if (i != 0)
-        {
-            var dosTime = await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false);
-            time = Utility.DosDateToDateTime(dosTime);
-        }
-        if ((rmode & 4) == 0 && time is not null)
-        {
-            time = time.Value.AddSeconds(1);
-        }
-        uint nanosecondHundreds = 0;
-        var count = (int)rmode & 3;
-        for (var j = 0; j < count; j++)
-        {
-            var b = await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-            nanosecondHundreds |= (((uint)b) << ((j + 3 - count) * 8));
-        }
-
-        if (time is not null)
-        {
-            return time.Value.AddMilliseconds(nanosecondHundreds * Math.Pow(10, -4));
-        }
-        return null;
-    }
-}