Add opt-in multi-threading support with SupportsMultiThreadedExtraction flag

- Added IArchive.SupportsMultiThreadedExtraction property to indicate if multi-threading is supported
- Added ReaderOptions.EnableMultiThreadedExtraction option to opt-in to multi-threading
- Updated SeekableZipFilePart, TarFilePart, and SeekableFilePart to check the flag
- Added test to verify multi-threading flag behavior
- Multi-threading is now disabled by default for backward compatibility

Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

AGENTS.md

@@ -179,58 +179,3 @@ SharpCompress supports multiple archive and compression formats:
 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
 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.Packages.props

@@ -12,7 +12,7 @@
     <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" />

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/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.

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)
@@ -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>();
@@ -139,6 +145,19 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     /// </summary>
     public virtual bool IsEncrypted => false;
 
+    /// <summary>
+    /// Returns whether multi-threaded extraction is supported for this archive.
+    /// Multi-threading is supported when:
+    /// 1. The archive is opened from a FileInfo or file path (not a stream)
+    /// 2. Multi-threading is explicitly enabled in ReaderOptions
+    /// 3. The archive is not SOLID (SOLID archives should use sequential extraction)
+    /// </summary>
+    public virtual bool SupportsMultiThreadedExtraction =>
+        _sourceStream is not null
+        && _sourceStream.IsFileMode
+        && ReaderOptions.EnableMultiThreadedExtraction
+        && !IsSolid;
+
     /// <summary>
     /// The archive can find all the parts of the archive needed to fully extract the archive.  This forces the parsing of the entire archive.
     /// </summary>
@@ -150,4 +169,85 @@ 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;
+
+    private async IAsyncEnumerable<IArchiveEntry> EntriesAsyncCast()
+    {
+        await foreach (var entry in EntriesAsync)
+        {
+            yield return entry;
+        }
+    }
+
+    IAsyncEnumerable<IArchiveEntry> IAsyncArchive.EntriesAsync => EntriesAsyncCast();
+
+    private async IAsyncEnumerable<IVolume> VolumesAsyncCast()
+    {
+        await foreach (var volume in VolumesAsync)
+        {
+            yield return volume;
+        }
+    }
+
+    public IAsyncEnumerable<IVolume> VolumesAsync => VolumesAsyncCast();
+
+    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.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/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

@@ -10,7 +10,7 @@ using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
 
-public abstract partial class AbstractWritableArchive<TEntry, TVolume>
+public abstract class AbstractWritableArchive<TEntry, TVolume>
     : AbstractArchive<TEntry, TVolume>,
         IWritableArchive,
         IWritableAsyncArchive
@@ -84,12 +84,12 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         }
     }
 
-    void IWritableArchive.RemoveEntry(IArchiveEntry entry) => RemoveEntry((TEntry)entry);
+    void IWritableArchiveCommon.RemoveEntry(IArchiveEntry entry) => RemoveEntry((TEntry)entry);
 
     public TEntry AddEntry(string key, Stream source, long size = 0, DateTime? modified = null) =>
         AddEntry(key, source, false, size, modified);
 
-    IArchiveEntry IWritableArchive.AddEntry(
+    IArchiveEntry IWritableArchiveCommon.AddEntry(
         string key,
         Stream source,
         bool closeStream,
@@ -97,7 +97,7 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         DateTime? modified
     ) => AddEntry(key, source, closeStream, size, modified);
 
-    IArchiveEntry IWritableArchive.AddDirectoryEntry(string key, DateTime? modified) =>
+    IArchiveEntry IWritableArchiveCommon.AddDirectoryEntry(string key, DateTime? modified) =>
         AddDirectoryEntry(key, modified);
 
     public TEntry AddEntry(
@@ -140,24 +140,6 @@ 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 +163,18 @@ 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 +212,7 @@ 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

@@ -11,7 +11,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public static partial class ArchiveFactory
+public static class ArchiveFactory
 {
     public static IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
     {
@@ -20,6 +20,18 @@ public static partial class ArchiveFactory
         return FindFactory<IArchiveFactory>(stream).OpenArchive(stream, readerOptions);
     }
 
+    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 IWritableArchive CreateArchive(ArchiveType type)
     {
         var factory = Factory
@@ -40,6 +52,16 @@ public static partial class ArchiveFactory
         return OpenArchive(new FileInfo(filePath), options);
     }
 
+    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 IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? options = null)
     {
         options ??= new ReaderOptions { LeaveStreamOpen = false };
@@ -47,6 +69,18 @@ public static partial class ArchiveFactory
         return FindFactory<IArchiveFactory>(fileInfo).OpenArchive(fileInfo, options);
     }
 
+    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, cancellationToken);
+    }
+
     public static IArchive OpenArchive(
         IEnumerable<FileInfo> fileInfos,
         ReaderOptions? options = null
@@ -71,6 +105,32 @@ public static partial class ArchiveFactory
         return FindFactory<IMultiArchiveFactory>(fileInfo).OpenArchive(filesArray, 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 IArchive OpenArchive(IEnumerable<Stream> streams, ReaderOptions? options = null)
     {
         streams.NotNull(nameof(streams));
@@ -92,6 +152,33 @@ public static partial class ArchiveFactory
         return FindFactory<IMultiArchiveFactory>(firstStream).OpenArchive(streamsArray, options);
     }
 
+    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 = FindFactory<IMultiArchiveFactory>(firstStream);
+        return factory.OpenAsyncArchive(streamsArray, options);
+    }
+
     public static void WriteToDirectory(
         string sourceArchive,
         string destinationDirectory,
@@ -102,15 +189,7 @@ public static partial class ArchiveFactory
         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 +197,7 @@ 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 +229,68 @@ 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));
@@ -212,4 +345,6 @@ 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 +1,52 @@
+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 OpenArchive(Stream stream, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.OpenArchive(stream, readerOptions);
+
+    public IAsyncArchive OpenAsyncArchive(Stream stream, ReaderOptions? readerOptions = null) =>
+        (IAsyncArchive)OpenArchive(stream, readerOptions);
+
+    public IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.OpenArchive(fileInfo, readerOptions);
+
+    public IAsyncArchive OpenAsyncArchive(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return (IAsyncArchive)OpenArchive(fileInfo, readerOptions);
+    }
+}

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

@@ -1,5 +1,4 @@
 using System;
-using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -181,21 +180,18 @@ public partial class GZipArchive
         CancellationToken cancellationToken = default
     )
     {
-        var header = ArrayPool<byte>.Shared.Rent(10);
-        try
-        {
-            await stream.ReadFullyAsync(header, 0, 10, cancellationToken).ConfigureAwait(false);
+        byte[] header = new byte[10];
 
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                return false;
-            }
-
-            return true;
-        }
-        finally
+        if (!await stream.ReadFullyAsync(header, cancellationToken).ConfigureAwait(false))
         {
-            ArrayPool<byte>.Shared.Return(header);
+            return false;
         }
+
+        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+        {
+            return false;
+        }
+
+        return true;
     }
 }

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -36,6 +36,19 @@ 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);
+    }
+
     protected override GZipArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -79,6 +92,28 @@ 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;
@@ -88,10 +123,28 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         );
     }
 
+    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)
+        );
+    }
+
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
         return GZipReader.OpenReader(stream);
     }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new((IAsyncReader)GZipReader.OpenReader(stream));
+    }
 }

src/SharpCompress/Archives/IArchive.cs

@@ -44,4 +44,12 @@ public interface IArchive : IDisposable
     /// Returns whether the archive is encrypted.
     /// </summary>
     bool IsEncrypted { get; }
+
+    /// <summary>
+    /// Returns whether multi-threaded extraction is supported for this archive.
+    /// Multi-threading is supported when the archive is opened from a FileInfo or file path
+    /// (not a stream) and the format supports random access (e.g., Zip, Tar, Rar).
+    /// SOLID archives (some Rar, all 7Zip) should use sequential extraction for best performance.
+    /// </summary>
+    bool SupportsMultiThreadedExtraction { 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/IArchiveFactory.cs

@@ -47,5 +47,9 @@ 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);
+    IAsyncArchive OpenAsyncArchive(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 }

src/SharpCompress/Archives/IAsyncArchiveExtensions.cs

@@ -20,7 +20,7 @@ public static class IAsyncArchiveExtensions
         /// <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(
+        public async Task WriteToDirectoryAsync(
             string destinationDirectory,
             ExtractionOptions? options = null,
             IProgress<ProgressReport>? progress = null,
@@ -47,7 +47,7 @@ public static class IAsyncArchiveExtensions
             }
         }
 
-        private async ValueTask WriteToDirectoryAsyncInternal(
+        private async Task WriteToDirectoryAsyncInternal(
             string destinationDirectory,
             ExtractionOptions? options,
             IProgress<ProgressReport>? progress,

src/SharpCompress/Archives/IWritableArchive.cs

@@ -13,10 +13,12 @@ public interface IWritableArchiveCommon
     /// </summary>
     /// <returns>IDisposeable to resume entry rebuilding</returns>
     IDisposable PauseEntryRebuilding();
-}
 
-public interface IWritableArchive : IArchive, IWritableArchiveCommon
-{
+    /// <summary>
+    /// Removes the specified entry from the archive.
+    /// </summary>
+    void RemoveEntry(IArchiveEntry entry);
+
     IArchiveEntry AddEntry(
         string key,
         Stream source,
@@ -26,16 +28,14 @@ public interface IWritableArchive : IArchive, IWritableArchiveCommon
     );
 
     IArchiveEntry AddDirectoryEntry(string key, DateTime? modified = null);
+}
 
+public interface IWritableArchive : IArchive, IWritableArchiveCommon
+{
     /// <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
@@ -48,30 +48,4 @@ public interface IWritableAsyncArchive : IAsyncArchive, IWritableArchiveCommon
         WriterOptions options,
         CancellationToken cancellationToken = default
     );
-
-    /// <summary>
-    /// Asynchronously adds an entry to the archive with the specified key, source stream, and options.
-    /// </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);
 }

src/SharpCompress/Archives/IWritableArchiveCommonExtensions.cs

@@ -0,0 +1,59 @@
+using System;
+using System.IO;
+
+namespace SharpCompress.Archives;
+
+public static class IWritableArchiveCommonExtensions
+{
+    extension(IWritableArchiveCommon writableArchive)
+    {
+        public void AddAllFromDirectory(
+            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);
+                    writableArchive.AddEntry(
+                        path.Substring(filePath.Length),
+                        fileInfo.OpenRead(),
+                        true,
+                        fileInfo.Length,
+                        fileInfo.LastWriteTime
+                    );
+                }
+            }
+        }
+
+        public IArchiveEntry AddEntry(string key, string file) =>
+            writableArchive.AddEntry(key, new FileInfo(file));
+
+        public IArchiveEntry AddEntry(
+            string key,
+            Stream source,
+            long size = 0,
+            DateTime? modified = null
+        ) => writableArchive.AddEntry(key, source, false, size, modified);
+
+        public IArchiveEntry AddEntry(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/IWritableArchiveExtensions.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Writers;
@@ -9,55 +8,6 @@ public static class IWritableArchiveExtensions
 {
     extension(IWritableArchive writableArchive)
     {
-        public void AddAllFromDirectory(
-            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);
-                    writableArchive.AddEntry(
-                        path.Substring(filePath.Length),
-                        fileInfo.OpenRead(),
-                        true,
-                        fileInfo.Length,
-                        fileInfo.LastWriteTime
-                    );
-                }
-            }
-        }
-
-        public IArchiveEntry AddEntry(string key, string file) =>
-            writableArchive.AddEntry(key, new FileInfo(file));
-
-        public IArchiveEntry AddEntry(
-            string key,
-            Stream source,
-            long size = 0,
-            DateTime? modified = null
-        ) => writableArchive.AddEntry(key, source, false, size, modified);
-
-        public IArchiveEntry AddEntry(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
-            );
-        }
-
         public void SaveTo(string filePath, WriterOptions? options = null) =>
             writableArchive.SaveTo(new FileInfo(filePath), options ?? new(CompressionType.Deflate));
 

src/SharpCompress/Archives/IWritableAsyncArchiveExtensions.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -11,55 +10,6 @@ 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,

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.Factory.cs

@@ -3,7 +3,6 @@ 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;
@@ -164,24 +163,4 @@ public partial class RarArchive
             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

@@ -24,10 +24,7 @@ public interface IRarArchive : IArchive, IRarArchiveCommon { }
 
 public interface IRarAsyncArchive : IAsyncArchive, IRarArchiveCommon { }
 
-public partial class RarArchive
-    : AbstractArchive<RarArchiveEntry, RarVolume>,
-        IRarArchive,
-        IRarAsyncArchive
+public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, IRarArchive
 {
     private bool _disposed;
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
@@ -51,14 +48,23 @@ 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 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();
@@ -80,7 +86,13 @@ public partial class RarArchive
         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())
         {
@@ -102,6 +114,5 @@ 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;
 }

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/SeekableFilePart.cs

@@ -1,6 +1,7 @@
 using System.IO;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
+using SharpCompress.IO;
 
 namespace SharpCompress.Archives.Rar;
 
@@ -24,6 +25,76 @@ internal class SeekableFilePart : RarFilePart
 
     internal override Stream GetCompressedStream()
     {
+        Stream streamToUse;
+
+        // If the stream is a SourceStream in file mode with multi-threading enabled,
+        // create an independent stream to support concurrent extraction
+        if (
+            _stream is SourceStream sourceStream
+            && sourceStream.IsFileMode
+            && sourceStream.ReaderOptions.EnableMultiThreadedExtraction
+        )
+        {
+            var independentStream = sourceStream.CreateIndependentStream(0);
+            if (independentStream is not null)
+            {
+                streamToUse = independentStream;
+                streamToUse.Position = FileHeader.DataStartPosition;
+
+                if (FileHeader.R4Salt != null)
+                {
+                    var cryptKey = new CryptKey3(_password!);
+                    return new RarCryptoWrapper(streamToUse, FileHeader.R4Salt, cryptKey);
+                }
+
+                if (FileHeader.Rar5CryptoInfo != null)
+                {
+                    var cryptKey = new CryptKey5(_password!, FileHeader.Rar5CryptoInfo);
+                    return new RarCryptoWrapper(
+                        streamToUse,
+                        FileHeader.Rar5CryptoInfo.Salt,
+                        cryptKey
+                    );
+                }
+
+                return streamToUse;
+            }
+        }
+
+        // Check if the stream wraps a FileStream
+        Stream? underlyingStream = _stream;
+        if (_stream is IStreamStack streamStack)
+        {
+            underlyingStream = streamStack.BaseStream();
+        }
+
+        if (underlyingStream is FileStream fileStream)
+        {
+            // Create a new independent stream from the file
+            streamToUse = new FileStream(
+                fileStream.Name,
+                FileMode.Open,
+                FileAccess.Read,
+                FileShare.Read
+            );
+            streamToUse.Position = FileHeader.DataStartPosition;
+
+            if (FileHeader.R4Salt != null)
+            {
+                var cryptKey = new CryptKey3(_password!);
+                return new RarCryptoWrapper(streamToUse, FileHeader.R4Salt, cryptKey);
+            }
+
+            if (FileHeader.Rar5CryptoInfo != null)
+            {
+                var cryptKey = new CryptKey5(_password!, FileHeader.Rar5CryptoInfo);
+                return new RarCryptoWrapper(streamToUse, FileHeader.Rar5CryptoInfo.Salt, cryptKey);
+            }
+
+            return streamToUse;
+        }
+
+        // Fall back to existing behavior for stream-based sources
         _stream.Position = FileHeader.DataStartPosition;
 
         if (FileHeader.R4Salt != null)

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

@@ -1,10 +1,12 @@
 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.SevenZip;
+using SharpCompress.Compressors.LZMA.Utilites;
 using SharpCompress.IO;
 using SharpCompress.Readers;
 
@@ -155,56 +157,13 @@ public partial class SevenZipArchive
         }
     }
 
-    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 ReadOnlySpan<byte> Signature =>
+        new byte[] { (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);
-        }
+        var reader = new BinaryReader(stream);
+        ReadOnlySpan<byte> signatureBytes = reader.ReadBytes(6);
+        return signatureBytes.SequenceEqual(Signature);
     }
 }

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -16,65 +16,48 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
 {
     private ArchiveDatabase? _database;
 
-    /// <summary>
-    /// Constructor with a SourceStream able to handle FileInfo and Streams.
-    /// </summary>
-    /// <param name="sourceStream"></param>
     private SevenZipArchive(SourceStream sourceStream)
         : base(ArchiveType.SevenZip, sourceStream) { }
 
-    protected override IEnumerable<SevenZipVolume> LoadVolumes(SourceStream sourceStream)
-    {
-        sourceStream.NotNull("SourceStream is null").LoadAllParts(); //request all streams
-        return new SevenZipVolume(sourceStream, ReaderOptions, 0).AsEnumerable(); //simple single volume or split, multivolume not supported
-    }
-
     internal SevenZipArchive()
         : base(ArchiveType.SevenZip) { }
 
+    protected override IEnumerable<SevenZipVolume> LoadVolumes(SourceStream sourceStream)
+    {
+        sourceStream.NotNull("SourceStream is null").LoadAllParts();
+        return new SevenZipVolume(sourceStream, ReaderOptions, 0).AsEnumerable();
+    }
+
     protected override IEnumerable<SevenZipArchiveEntry> LoadEntries(
         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;
             }
         }
+
+        return entries;
     }
 
     private void LoadFactory(Stream stream)
@@ -91,6 +74,9 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
     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 +88,13 @@ 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 +107,6 @@ 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.
             foreach (var entry in entries.Where(x => !x.IsDirectory))
             {
                 _currentEntry = entry;
@@ -160,53 +121,10 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
             {
                 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()));
         }
     }
 
-    /// <summary>
-    /// WORKAROUND: Forces async operations to use synchronous equivalents.
-    /// This is necessary because the LZMA decoder has bugs in its async implementation
-    /// that cause state corruption (IndexOutOfRangeException, DataErrorException).
-    ///
-    /// The proper fix would be to repair the LZMA decoder's async methods
-    /// (LzmaStream.ReadAsync, Decoder.CodeAsync, OutWindow async operations),
-    /// but that requires deep changes to the decoder state machine.
-    /// </summary>
     private sealed class SyncOnlyStream : Stream
     {
         private readonly Stream _baseStream;
@@ -236,7 +154,6 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
         public override void Write(byte[] buffer, int offset, int count) =>
             _baseStream.Write(buffer, offset, count);
 
-        // Force async operations to use sync equivalents to avoid LZMA decoder bugs
         public override Task<int> ReadAsync(
             byte[] buffer,
             int offset,

src/SharpCompress/Archives/SevenZip/SevenZipArchiveEntry.cs

@@ -12,9 +12,8 @@ public class SevenZipArchiveEntry : SevenZipEntry, IArchiveEntry
 
     public Stream OpenEntryStream() => FilePart.GetCompressedStream();
 
-    public async ValueTask<Stream> OpenEntryStreamAsync(
-        CancellationToken cancellationToken = default
-    ) => (await FilePart.GetCompressedStreamAsync(cancellationToken)).NotNull();
+    public ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default) =>
+        new(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

@@ -2,13 +2,15 @@ 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;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.IO;
 using SharpCompress.Readers;
+using SharpCompress.Writers;
+using SharpCompress.Writers.Tar;
 
 namespace SharpCompress.Archives.Tar;
 
@@ -21,7 +23,7 @@ public partial class TarArchive
     public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
+        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
     public static IWritableArchive OpenArchive(
@@ -34,7 +36,7 @@ public partial class TarArchive
             new SourceStream(
                 fileInfo,
                 i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -50,7 +52,7 @@ public partial class TarArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -152,44 +154,15 @@ public partial class TarArchive
         try
         {
             var tarHeader = new TarHeader(new ArchiveEncoding());
-            var reader = new BinaryReader(stream, Encoding.UTF8, false);
-            var readSucceeded = tarHeader.Read(reader);
+            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 (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;
-        }
+        catch { }
+        return false;
     }
 
     public static IWritableArchive CreateArchive() => new TarArchive();

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -32,10 +32,6 @@ 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 +62,7 @@ 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();
 
@@ -143,10 +139,54 @@ 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);
     }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new((IAsyncReader)TarReader.OpenReader(stream));
+    }
 }

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

@@ -21,7 +21,7 @@ public partial class ZipArchive
     public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
+        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
     public static IWritableArchive OpenArchive(
@@ -34,7 +34,7 @@ public partial class ZipArchive
             new SourceStream(
                 fileInfo,
                 i => ZipArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -50,7 +50,7 @@ public partial class ZipArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -135,24 +135,40 @@ public partial class ZipArchive
         return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
     }
 
-    public static bool IsZipFile(string filePath, string? password = null) =>
-        IsZipFile(new FileInfo(filePath), password);
+    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)
+    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);
+        return IsZipFile(stream, password, bufferSize);
     }
 
-    public static bool IsZipFile(Stream stream, string? password = null)
+    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);
@@ -172,14 +188,18 @@ public partial class ZipArchive
         }
     }
 
-    public static bool IsZipMulti(Stream stream, string? password = null)
+    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: Constants.BufferSize);
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
             }
 
             var header = headerFactory
@@ -190,7 +210,7 @@ public partial class ZipArchive
                 if (stream.CanSeek)
                 {
                     var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    var x = z.ReadSeekableHeader(stream).FirstOrDefault();
+                    var x = z.ReadSeekableHeader(stream, useSync: true).FirstOrDefault();
                     return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
                 }
                 else
@@ -213,6 +233,7 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipFileAsync(
         Stream stream,
         string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -222,7 +243,7 @@ public partial class ZipArchive
         {
             if (stream is not SharpCompressStream)
             {
-                stream = new SharpCompressStream(stream, bufferSize: Constants.BufferSize);
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
             }
 
             var header = await headerFactory
@@ -252,6 +273,7 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipMultiAsync(
         Stream stream,
         string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -261,7 +283,7 @@ public partial class ZipArchive
         {
             if (stream is not SharpCompressStream)
             {
-                stream = new SharpCompressStream(stream, bufferSize: Constants.BufferSize);
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
             }
 
             var header = headerFactory

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -41,12 +41,9 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         var idx = 0;
         if (streams.Count() > 1)
         {
-            //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;
+            var isZip = IsZipFile(streams[1], ReaderOptions.Password, ReaderOptions.BufferSize);
+            streams[1].Position -= 4;
             if (isZip)
             {
                 stream.IsVolumes = true;
@@ -65,7 +62,9 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
     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 +108,59 @@ 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 +192,41 @@ 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,

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;
 

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 !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 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 !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
+
     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;
 
@@ -42,6 +42,4 @@ public partial class GZipEntry : Entry
     {
         yield return new GZipEntry(GZipFilePart.Create(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

@@ -2,13 +2,15 @@ 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;
 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;
@@ -35,6 +37,32 @@ internal sealed partial class GZipFilePart : FilePart
         return part;
     }
 
+    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 GZipFilePart(Stream stream, IArchiveEncoding archiveEncoding)
         : base(archiveEncoding) => _stream = stream;
 
@@ -47,12 +75,7 @@ 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;
 
@@ -66,6 +89,16 @@ internal sealed partial class GZipFilePart : FilePart
         UncompressedSize = BinaryPrimitives.ReadUInt32LittleEndian(trailer.Slice(4));
     }
 
+    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 void ReadAndValidateGzipHeader()
     {
         // read the header on the first read
@@ -118,6 +151,61 @@ internal sealed partial class GZipFilePart : FilePart
         }
     }
 
+    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 string ReadZeroTerminatedString(Stream stream)
     {
         Span<byte> buf1 = stackalloc byte[1];
@@ -143,4 +231,33 @@ internal sealed partial class GZipFilePart : FilePart
         var buffer = list.ToArray();
         return ArchiveEncoding.Decode(buffer);
     }
+
+    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/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;
-    }
-}

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

@@ -2,9 +2,6 @@ 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;
@@ -16,15 +13,12 @@ using size_t = System.UInt64;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal partial class FileHeader : RarHeader
+internal class FileHeader : RarHeader
 {
     private byte[]? _hash;
 
-    public static FileHeader Create(
-        RarHeader header,
-        RarCrcBinaryReader reader,
-        HeaderType headerType
-    ) => CreateChild<FileHeader>(header, reader, headerType);
+    public FileHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
+        : base(header, reader, headerType) { }
 
     protected override void ReadFinish(MarkingBinaryReader reader)
     {
@@ -82,6 +76,23 @@ internal partial class FileHeader : RarHeader
 
         var nameSize = reader.ReadRarVIntUInt16();
 
+        // Variable length field containing Name length bytes in UTF-8 format without trailing zero.
+        // For file header this is a name of archived file. Forward slash character is used as the path separator both for Unix and Windows names.
+        // Backslashes are treated as a part of name for Unix names and as invalid character for Windows file names. Type of name is defined by Host OS field.
+        //
+        // TODO: not sure if anything needs to be done to handle the following:
+        // If Unix file name contains any high ASCII characters which cannot be correctly converted to Unicode and UTF-8
+        // we map such characters to to 0xE080 - 0xE0FF private use Unicode area and insert 0xFFFE Unicode non-character
+        // to resulting string to indicate that it contains mapped characters, which need to be converted back when extracting.
+        // Concrete position of 0xFFFE is not defined, we need to search the entire string for it. Such mapped names are not
+        // portable and can be correctly unpacked only on the same system where they were created.
+        //
+        // For service header this field contains a name of service header. Now the following names are used:
+        // CMT	Archive comment
+        // QO	Archive quick open data
+        // ACL	NTFS file permissions
+        // STM	NTFS alternate data stream
+        // RR	Recovery record
         var b = reader.ReadBytes(nameSize);
         FileName = ConvertPathV5(Encoding.UTF8.GetString(b, 0, b.Length));
 
@@ -108,7 +119,7 @@ internal partial class FileHeader : RarHeader
             {
                 case FHEXTRA_CRYPT: // file encryption
                     {
-                        Rar5CryptoInfo = Rar5CryptoInfo.Create(reader, true);
+                        Rar5CryptoInfo = new Rar5CryptoInfo(reader, true);
 
                         if (Rar5CryptoInfo.PswCheck.All(singleByte => singleByte == 0))
                         {
@@ -119,11 +130,14 @@ internal partial class FileHeader : RarHeader
                 case FHEXTRA_HASH:
                     {
                         const uint FHEXTRA_HASH_BLAKE2 = 0x0;
+                        //                        const uint HASH_BLAKE2 = 0x03;
                         const int BLAKE2_DIGEST_SIZE = 0x20;
                         if ((uint)reader.ReadRarVInt() == FHEXTRA_HASH_BLAKE2)
                         {
+                            //                            var hash = HASH_BLAKE2;
                             _hash = reader.ReadBytes(BLAKE2_DIGEST_SIZE);
                         }
+                        // enum HASH_TYPE {HASH_NONE,HASH_RAR14,HASH_CRC32,HASH_BLAKE2};
                     }
                     break;
                 case FHEXTRA_HTIME: // file time
@@ -144,6 +158,12 @@ internal partial class FileHeader : RarHeader
                         }
                     }
                     break;
+                //TODO
+                //                    case FHEXTRA_VERSION: // file version
+                //                        {
+                //
+                //                        }
+                //                        break;
                 case FHEXTRA_REDIR: // file system redirection
                     {
                         RedirType = reader.ReadRarVIntByte();
@@ -153,7 +173,21 @@ internal partial class FileHeader : RarHeader
                         RedirTargetName = ConvertPathV5(Encoding.UTF8.GetString(bb, 0, bb.Length));
                     }
                     break;
+                //TODO
+                //                    case FHEXTRA_UOWNER: // unix owner
+                //                        {
+                //
+                //                        }
+                //                        break;
+                //                    case FHEXTRA_SUBDATA: // service data
+                //                        {
+                //
+                //                        }
+                //                        break;
+
                 default:
+                    // skip unknown record types to allow new record types to be added in the future
+                    //Console.WriteLine($"unhandled rar header field type {type}");
                     break;
             }
             // drain any trailing bytes of extra record
@@ -302,6 +336,8 @@ internal partial class FileHeader : RarHeader
         }
         if (HasFlag(FileFlagsV4.EXT_TIME))
         {
+            // verify that the end of the header hasn't been reached before reading the Extended Time.
+            //  some tools incorrectly omit Extended Time despite specifying FileFlags.EXTTIME, which most parsers tolerate.
             if (RemainingHeaderBytes(reader) >= 2)
             {
                 var extendedFlags = reader.ReadUInt16();

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

@@ -1,132 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal partial class MarkHeader
-{
-    private static async ValueTask<byte> GetByteAsync(
-        Stream stream,
-        CancellationToken cancellationToken
-    )
-    {
-        var buffer = new byte[1];
-        var bytesRead = await stream
-            .ReadAsync(buffer, 0, 1, cancellationToken)
-            .ConfigureAwait(false);
-        if (bytesRead == 1)
-        {
-            return buffer[0];
-        }
-        throw new EndOfStreamException();
-    }
-
-    public static async ValueTask<MarkHeader> ReadAsync(
-        Stream stream,
-        bool leaveStreamOpen,
-        bool lookForHeader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var maxScanIndex = lookForHeader ? MAX_SFX_SIZE : 0;
-        try
-        {
-            var start = -1;
-            var b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-            start++;
-            while (start <= maxScanIndex)
-            {
-                if (b == 0x52)
-                {
-                    b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                    start++;
-                    if (b == 0x61)
-                    {
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x72)
-                        {
-                            continue;
-                        }
-
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x21)
-                        {
-                            continue;
-                        }
-
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x1a)
-                        {
-                            continue;
-                        }
-
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x07)
-                        {
-                            continue;
-                        }
-
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b == 1)
-                        {
-                            b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                            start++;
-                            if (b != 0)
-                            {
-                                continue;
-                            }
-
-                            return new MarkHeader(true); // Rar5
-                        }
-                        else if (b == 0)
-                        {
-                            return new MarkHeader(false); // Rar4
-                        }
-                    }
-                    else if (b == 0x45)
-                    {
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x7e)
-                        {
-                            continue;
-                        }
-
-                        b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                        start++;
-                        if (b != 0x5e)
-                        {
-                            continue;
-                        }
-
-                        throw new InvalidFormatException(
-                            "Rar format version pre-4 is unsupported."
-                        );
-                    }
-                }
-                else
-                {
-                    b = await GetByteAsync(stream, cancellationToken).ConfigureAwait(false);
-                    start++;
-                }
-            }
-        }
-        catch (Exception e)
-        {
-            if (!leaveStreamOpen)
-            {
-                stream.Dispose();
-            }
-            throw new InvalidFormatException("Error trying to read rar signature.", e);
-        }
-
-        throw new InvalidFormatException("Rar signature not found");
-    }
-}

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

@@ -1,11 +1,9 @@
 using System;
 using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal partial class MarkHeader : IRarHeader
+internal class MarkHeader : IRarHeader
 {
     private const int MAX_SFX_SIZE = 0x80000 - 16; //archive.cpp line 136
 

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

@@ -1,40 +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 ProtectHeader
-{
-    public static async ValueTask<ProtectHeader> CreateAsync(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var c = await CreateChildAsync<ProtectHeader>(
-                header,
-                reader,
-                HeaderType.Protect,
-                cancellationToken
-            )
-            .ConfigureAwait(false);
-        if (c.IsRar5)
-        {
-            throw new InvalidFormatException("unexpected rar5 record");
-        }
-        return c;
-    }
-
-    protected sealed override async ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        Version = await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-        RecSectors = await reader.ReadUInt16Async(cancellationToken).ConfigureAwait(false);
-        TotalBlocks = await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false);
-        Mark = await reader.ReadBytesAsync(8, cancellationToken).ConfigureAwait(false);
-    }
-}

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

@@ -1,21 +1,20 @@
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-internal sealed partial class ProtectHeader : RarHeader
+// ProtectHeader is part of the Recovery Record feature
+internal sealed class ProtectHeader : RarHeader
 {
-    public static ProtectHeader Create(RarHeader header, RarCrcBinaryReader reader)
+    public ProtectHeader(RarHeader header, RarCrcBinaryReader reader)
+        : base(header, reader, HeaderType.Protect)
     {
-        var c = CreateChild<ProtectHeader>(header, reader, HeaderType.Protect);
-        if (c.IsRar5)
+        if (IsRar5)
         {
             throw new InvalidFormatException("unexpected rar5 record");
         }
-        return c;
     }
 
-    protected sealed override void ReadFinish(MarkingBinaryReader reader)
+    protected override void ReadFinish(MarkingBinaryReader reader)
     {
         Version = reader.ReadByte();
         RecSectors = reader.ReadUInt16();

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

@@ -1,115 +0,0 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-internal partial class RarHeader
-{
-    internal static async ValueTask<RarHeader?> TryReadBaseAsync(
-        AsyncRarCrcBinaryReader reader,
-        bool isRar5,
-        IArchiveEncoding archiveEncoding,
-        CancellationToken cancellationToken = default
-    )
-    {
-        try
-        {
-            var header = new RarHeader();
-            await header
-                .InitializeAsync(reader, isRar5, archiveEncoding, cancellationToken)
-                .ConfigureAwait(false);
-            return header;
-        }
-        catch (InvalidFormatException)
-        {
-            return null;
-        }
-    }
-
-    private async ValueTask InitializeAsync(
-        AsyncRarCrcBinaryReader reader,
-        bool isRar5,
-        IArchiveEncoding archiveEncoding,
-        CancellationToken cancellationToken
-    )
-    {
-        _headerType = HeaderType.Null;
-        _isRar5 = isRar5;
-        ArchiveEncoding = archiveEncoding;
-        if (IsRar5)
-        {
-            HeaderCrc = await reader.ReadUInt32Async(cancellationToken).ConfigureAwait(false);
-            reader.ResetCrc();
-            HeaderSize = (int)
-                await reader.ReadRarVIntUInt32Async(3, cancellationToken).ConfigureAwait(false);
-            reader.Mark();
-            HeaderCode = await reader
-                .ReadRarVIntByteAsync(cancellationToken: cancellationToken)
-                .ConfigureAwait(false);
-            HeaderFlags = await reader
-                .ReadRarVIntUInt16Async(2, cancellationToken)
-                .ConfigureAwait(false);
-
-            if (HasHeaderFlag(HeaderFlagsV5.HAS_EXTRA))
-            {
-                ExtraSize = await reader
-                    .ReadRarVIntUInt32Async(cancellationToken: cancellationToken)
-                    .ConfigureAwait(false);
-            }
-            if (HasHeaderFlag(HeaderFlagsV5.HAS_DATA))
-            {
-                AdditionalDataSize = (long)
-                    await reader
-                        .ReadRarVIntAsync(cancellationToken: cancellationToken)
-                        .ConfigureAwait(false);
-            }
-        }
-        else
-        {
-            reader.Mark();
-            HeaderCrc = await reader.ReadUInt16Async(cancellationToken).ConfigureAwait(false);
-            reader.ResetCrc();
-            HeaderCode = await reader.ReadByteAsync(cancellationToken).ConfigureAwait(false);
-            HeaderFlags = await reader.ReadUInt16Async(cancellationToken).ConfigureAwait(false);
-            HeaderSize = await reader.ReadInt16Async(cancellationToken).ConfigureAwait(false);
-            if (HasHeaderFlag(HeaderFlagsV4.HAS_DATA))
-            {
-                AdditionalDataSize = await reader
-                    .ReadUInt32Async(cancellationToken)
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-
-    internal static async ValueTask<T> CreateChildAsync<T>(
-        RarHeader header,
-        AsyncRarCrcBinaryReader reader,
-        HeaderType headerType,
-        CancellationToken cancellationToken = default
-    )
-        where T : RarHeader, new()
-    {
-        var child = new T() { ArchiveEncoding = header.ArchiveEncoding };
-        child._headerType = headerType;
-        child._isRar5 = header.IsRar5;
-        child.HeaderCrc = header.HeaderCrc;
-        child.HeaderCode = header.HeaderCode;
-        child.HeaderFlags = header.HeaderFlags;
-        child.HeaderSize = header.HeaderSize;
-        child.ExtraSize = header.ExtraSize;
-        child.AdditionalDataSize = header.AdditionalDataSize;
-        await child.ReadFinishAsync(reader, cancellationToken).ConfigureAwait(false);
-
-        var n = child.RemainingHeaderBytesAsync(reader);
-        if (n > 0)
-        {
-            await reader.ReadBytesAsync(n, cancellationToken).ConfigureAwait(false);
-        }
-
-        child.VerifyHeaderCrc(reader.GetCrc32());
-        return child;
-    }
-}

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

@@ -1,22 +1,14 @@
 using System;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
 // http://www.forensicswiki.org/w/images/5/5b/RARFileStructure.txt
 // https://www.rarlab.com/technote.htm
-internal partial class RarHeader : IRarHeader
+internal class RarHeader : IRarHeader
 {
-    private HeaderType _headerType;
-    private bool _isRar5;
-
-    protected RarHeader()
-    {
-        ArchiveEncoding = new ArchiveEncoding();
-    }
+    private readonly HeaderType _headerType;
+    private readonly bool _isRar5;
 
     internal static RarHeader? TryReadBase(
         RarCrcBinaryReader reader,
@@ -26,9 +18,7 @@ internal partial class RarHeader : IRarHeader
     {
         try
         {
-            var header = new RarHeader();
-            header.Initialize(reader, isRar5, archiveEncoding);
-            return header;
+            return new RarHeader(reader, isRar5, archiveEncoding);
         }
         catch (InvalidFormatException)
         {
@@ -36,11 +26,7 @@ internal partial class RarHeader : IRarHeader
         }
     }
 
-    private void Initialize(
-        RarCrcBinaryReader reader,
-        bool isRar5,
-        IArchiveEncoding archiveEncoding
-    )
+    private RarHeader(RarCrcBinaryReader reader, bool isRar5, IArchiveEncoding archiveEncoding)
     {
         _headerType = HeaderType.Null;
         _isRar5 = isRar5;
@@ -78,48 +64,34 @@ internal partial class RarHeader : IRarHeader
         }
     }
 
-    internal static T CreateChild<T>(
-        RarHeader header,
-        RarCrcBinaryReader reader,
-        HeaderType headerType
-    )
-        where T : RarHeader, new()
+    protected RarHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
     {
-        var child = new T() { ArchiveEncoding = header.ArchiveEncoding };
-        child._headerType = headerType;
-        child._isRar5 = header.IsRar5;
-        child.HeaderCrc = header.HeaderCrc;
-        child.HeaderCode = header.HeaderCode;
-        child.HeaderFlags = header.HeaderFlags;
-        child.HeaderSize = header.HeaderSize;
-        child.ExtraSize = header.ExtraSize;
-        child.AdditionalDataSize = header.AdditionalDataSize;
-        child.ReadFinish(reader);
+        _headerType = headerType;
+        _isRar5 = header.IsRar5;
+        HeaderCrc = header.HeaderCrc;
+        HeaderCode = header.HeaderCode;
+        HeaderFlags = header.HeaderFlags;
+        HeaderSize = header.HeaderSize;
+        ExtraSize = header.ExtraSize;
+        AdditionalDataSize = header.AdditionalDataSize;
+        ArchiveEncoding = header.ArchiveEncoding;
+        ReadFinish(reader);
 
-        var n = child.RemainingHeaderBytes(reader);
+        var n = RemainingHeaderBytes(reader);
         if (n > 0)
         {
             reader.ReadBytes(n);
         }
 
-        child.VerifyHeaderCrc(reader.GetCrc32());
-        return child;
+        VerifyHeaderCrc(reader.GetCrc32());
     }
 
     protected int RemainingHeaderBytes(MarkingBinaryReader reader) =>
         checked(HeaderSize - (int)reader.CurrentReadByteCount);
 
-    protected int RemainingHeaderBytesAsync(AsyncMarkingBinaryReader reader) =>
-        checked(HeaderSize - (int)reader.CurrentReadByteCount);
-
     protected virtual void ReadFinish(MarkingBinaryReader reader) =>
         throw new NotImplementedException();
 
-    protected virtual ValueTask ReadFinishAsync(
-        AsyncMarkingBinaryReader reader,
-        CancellationToken cancellationToken = default
-    ) => throw new NotImplementedException();
-
     private void VerifyHeaderCrc(uint crc32)
     {
         var b = (IsRar5 ? crc32 : (ushort)crc32) == HeaderCrc;
@@ -131,27 +103,27 @@ internal partial class RarHeader : IRarHeader
 
     public HeaderType HeaderType => _headerType;
 
-    internal bool IsRar5 => _isRar5;
+    protected bool IsRar5 => _isRar5;
 
-    protected uint HeaderCrc { get; private set; }
+    protected uint HeaderCrc { get; }
 
-    internal byte HeaderCode { get; private set; }
+    internal byte HeaderCode { get; }
 
-    protected ushort HeaderFlags { get; private set; }
+    protected ushort HeaderFlags { get; }
 
     protected bool HasHeaderFlag(ushort flag) => (HeaderFlags & flag) == flag;
 
-    protected int HeaderSize { get; private set; }
+    protected int HeaderSize { get; }
 
-    internal IArchiveEncoding ArchiveEncoding { get; private set; }
+    internal IArchiveEncoding ArchiveEncoding { get; }
 
     /// <summary>
     /// Extra header size.
     /// </summary>
-    protected uint ExtraSize { get; private set; }
+    protected uint ExtraSize { get; }
 
     /// <summary>
     /// Size of additional data (eg file contents)
     /// </summary>
-    protected long AdditionalDataSize { get; private set; }
+    protected long AdditionalDataSize { get; }
 }

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

@@ -1,256 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common.Rar;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Common.Rar.Headers;
-
-public partial class RarHeaderFactory
-{
-    public async IAsyncEnumerable<IRarHeader> ReadHeadersAsync(Stream stream)
-    {
-        var markHeader = await MarkHeader
-            .ReadAsync(
-                stream,
-                Options.LeaveStreamOpen,
-                Options.LookForHeader,
-                CancellationToken.None
-            )
-            .ConfigureAwait(false);
-        _isRar5 = markHeader.IsRar5;
-        yield return markHeader;
-
-        RarHeader? header;
-        while (
-            (
-                header = await TryReadNextHeaderAsync(stream, CancellationToken.None)
-                    .ConfigureAwait(false)
-            ) != null
-        )
-        {
-            yield return header;
-            if (header.HeaderType == HeaderType.EndArchive)
-            {
-                // End of archive marker. RAR does not read anything after this header letting to use third
-                // party tools to add extra information such as a digital signature to archive.
-                yield break;
-            }
-        }
-    }
-
-    private async ValueTask<RarHeader?> TryReadNextHeaderAsync(
-        Stream stream,
-        CancellationToken cancellationToken
-    )
-    {
-        AsyncRarCrcBinaryReader reader;
-        if (!IsEncrypted)
-        {
-            reader = new AsyncRarCrcBinaryReader(stream);
-        }
-        else
-        {
-            if (Options.Password is null)
-            {
-                throw new CryptographicException(
-                    "Encrypted Rar archive has no password specified."
-                );
-            }
-
-            if (_isRar5 && _cryptInfo != null)
-            {
-                await _cryptInfo.ReadInitVAsync(new AsyncMarkingBinaryReader(stream));
-                var _headerKey = new CryptKey5(Options.Password!, _cryptInfo);
-
-                reader = await AsyncRarCryptoBinaryReader.Create(
-                    stream,
-                    _headerKey,
-                    _cryptInfo.Salt
-                );
-            }
-            else
-            {
-                var key = new CryptKey3(Options.Password);
-                reader = await AsyncRarCryptoBinaryReader.Create(stream, key);
-            }
-        }
-
-        var header = await RarHeader
-            .TryReadBaseAsync(reader, _isRar5, Options.ArchiveEncoding, cancellationToken)
-            .ConfigureAwait(false);
-        if (header is null)
-        {
-            return null;
-        }
-        switch (header.HeaderCode)
-        {
-            case HeaderCodeV.RAR5_ARCHIVE_HEADER:
-            case HeaderCodeV.RAR4_ARCHIVE_HEADER:
-            {
-                var ah = await ArchiveHeader
-                    .CreateAsync(header, reader, cancellationToken)
-                    .ConfigureAwait(false);
-                if (ah.IsEncrypted == true)
-                {
-                    //!!! rar5 we don't know yet
-                    IsEncrypted = true;
-                }
-                return ah;
-            }
-
-            case HeaderCodeV.RAR4_PROTECT_HEADER:
-            {
-                var ph = await ProtectHeader
-                    .CreateAsync(header, reader, cancellationToken)
-                    .ConfigureAwait(false);
-                // skip the recovery record data, we do not use it.
-                switch (StreamingMode)
-                {
-                    case StreamingMode.Seekable:
-                        {
-                            reader.BaseStream.Position += ph.DataSize;
-                        }
-                        break;
-                    case StreamingMode.Streaming:
-                        {
-                            await reader
-                                .BaseStream.SkipAsync(ph.DataSize, cancellationToken)
-                                .ConfigureAwait(false);
-                        }
-                        break;
-                    default:
-                    {
-                        throw new InvalidFormatException("Invalid StreamingMode");
-                    }
-                }
-                return ph;
-            }
-
-            case HeaderCodeV.RAR5_SERVICE_HEADER:
-            {
-                var fh = await FileHeader
-                    .CreateAsync(header, reader, HeaderType.Service, cancellationToken)
-                    .ConfigureAwait(false);
-                if (fh.FileName == "CMT")
-                {
-                    fh.PackedStream = new ReadOnlySubStream(reader.BaseStream, fh.CompressedSize);
-                }
-                else
-                {
-                    await SkipDataAsync(fh, reader, cancellationToken).ConfigureAwait(false);
-                }
-                return fh;
-            }
-
-            case HeaderCodeV.RAR4_NEW_SUB_HEADER:
-            {
-                var fh = await FileHeader
-                    .CreateAsync(header, reader, HeaderType.NewSub, cancellationToken)
-                    .ConfigureAwait(false);
-                await SkipDataAsync(fh, reader, cancellationToken).ConfigureAwait(false);
-                return fh;
-            }
-
-            case HeaderCodeV.RAR5_FILE_HEADER:
-            case HeaderCodeV.RAR4_FILE_HEADER:
-            {
-                var fh = await FileHeader
-                    .CreateAsync(header, reader, HeaderType.File, cancellationToken)
-                    .ConfigureAwait(false);
-                switch (StreamingMode)
-                {
-                    case StreamingMode.Seekable:
-                        {
-                            fh.DataStartPosition = reader.BaseStream.Position;
-                            reader.BaseStream.Position += fh.CompressedSize;
-                        }
-                        break;
-                    case StreamingMode.Streaming:
-                        {
-                            var ms = new ReadOnlySubStream(reader.BaseStream, fh.CompressedSize);
-                            if (fh.R4Salt is null && fh.Rar5CryptoInfo is null)
-                            {
-                                fh.PackedStream = ms;
-                            }
-                            else
-                            {
-                                fh.PackedStream = new RarCryptoWrapper(
-                                    ms,
-                                    fh.R4Salt is null
-                                        ? fh.Rar5CryptoInfo.NotNull().Salt
-                                        : fh.R4Salt,
-                                    fh.R4Salt is null
-                                        ? new CryptKey5(
-                                            Options.Password,
-                                            fh.Rar5CryptoInfo.NotNull()
-                                        )
-                                        : new CryptKey3(Options.Password)
-                                );
-                            }
-                        }
-                        break;
-                    default:
-                    {
-                        throw new InvalidFormatException("Invalid StreamingMode");
-                    }
-                }
-                return fh;
-            }
-            case HeaderCodeV.RAR5_END_ARCHIVE_HEADER:
-            case HeaderCodeV.RAR4_END_ARCHIVE_HEADER:
-            {
-                return await EndArchiveHeader
-                    .CreateAsync(header, reader, cancellationToken)
-                    .ConfigureAwait(false);
-            }
-            case HeaderCodeV.RAR5_ARCHIVE_ENCRYPTION_HEADER:
-            {
-                var cryptoHeader = await ArchiveCryptHeader
-                    .CreateAsync(header, reader, cancellationToken)
-                    .ConfigureAwait(false);
-                IsEncrypted = true;
-                _cryptInfo = cryptoHeader.CryptInfo;
-
-                return cryptoHeader;
-            }
-            default:
-            {
-                throw new InvalidFormatException("Unknown Rar Header: " + header.HeaderCode);
-            }
-        }
-    }
-
-    private async ValueTask SkipDataAsync(
-        FileHeader fh,
-        AsyncRarCrcBinaryReader reader,
-        CancellationToken cancellationToken
-    )
-    {
-        switch (StreamingMode)
-        {
-            case StreamingMode.Seekable:
-                {
-                    fh.DataStartPosition = reader.BaseStream.Position;
-                    reader.BaseStream.Position += fh.CompressedSize;
-                }
-                break;
-            case StreamingMode.Streaming:
-                {
-                    //skip the data because it's useless?
-                    await reader
-                        .BaseStream.SkipAsync(fh.CompressedSize, cancellationToken)
-                        .ConfigureAwait(false);
-                }
-                break;
-            default:
-            {
-                throw new InvalidFormatException("Invalid StreamingMode");
-            }
-        }
-    }
-}

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

@@ -1,14 +1,11 @@
-using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 using SharpCompress.Readers;
 
 namespace SharpCompress.Common.Rar.Headers;
 
-public partial class RarHeaderFactory
+public class RarHeaderFactory
 {
     private bool _isRar5;
 
@@ -64,12 +61,12 @@ public partial class RarHeaderFactory
                 _cryptInfo.ReadInitV(new MarkingBinaryReader(stream));
                 var _headerKey = new CryptKey5(Options.Password!, _cryptInfo);
 
-                reader = RarCryptoBinaryReader.Create(stream, _headerKey, _cryptInfo.Salt);
+                reader = new RarCryptoBinaryReader(stream, _headerKey, _cryptInfo.Salt);
             }
             else
             {
                 var key = new CryptKey3(Options.Password);
-                reader = RarCryptoBinaryReader.Create(stream, key);
+                reader = new RarCryptoBinaryReader(stream, key);
             }
         }
 
@@ -83,7 +80,7 @@ public partial class RarHeaderFactory
             case HeaderCodeV.RAR5_ARCHIVE_HEADER:
             case HeaderCodeV.RAR4_ARCHIVE_HEADER:
             {
-                var ah = ArchiveHeader.Create(header, reader);
+                var ah = new ArchiveHeader(header, reader);
                 if (ah.IsEncrypted == true)
                 {
                     //!!! rar5 we don't know yet
@@ -94,7 +91,7 @@ public partial class RarHeaderFactory
 
             case HeaderCodeV.RAR4_PROTECT_HEADER:
             {
-                var ph = ProtectHeader.Create(header, reader);
+                var ph = new ProtectHeader(header, reader);
                 // skip the recovery record data, we do not use it.
                 switch (StreamingMode)
                 {
@@ -119,7 +116,7 @@ public partial class RarHeaderFactory
 
             case HeaderCodeV.RAR5_SERVICE_HEADER:
             {
-                var fh = FileHeader.Create(header, reader, HeaderType.Service);
+                var fh = new FileHeader(header, reader, HeaderType.Service);
                 if (fh.FileName == "CMT")
                 {
                     fh.PackedStream = new ReadOnlySubStream(reader.BaseStream, fh.CompressedSize);
@@ -133,7 +130,7 @@ public partial class RarHeaderFactory
 
             case HeaderCodeV.RAR4_NEW_SUB_HEADER:
             {
-                var fh = FileHeader.Create(header, reader, HeaderType.NewSub);
+                var fh = new FileHeader(header, reader, HeaderType.NewSub);
                 SkipData(fh, reader);
                 return fh;
             }
@@ -141,7 +138,7 @@ public partial class RarHeaderFactory
             case HeaderCodeV.RAR5_FILE_HEADER:
             case HeaderCodeV.RAR4_FILE_HEADER:
             {
-                var fh = FileHeader.Create(header, reader, HeaderType.File);
+                var fh = new FileHeader(header, reader, HeaderType.File);
                 switch (StreamingMode)
                 {
                     case StreamingMode.Seekable:
@@ -184,11 +181,11 @@ public partial class RarHeaderFactory
             case HeaderCodeV.RAR5_END_ARCHIVE_HEADER:
             case HeaderCodeV.RAR4_END_ARCHIVE_HEADER:
             {
-                return EndArchiveHeader.Create(header, reader);
+                return new EndArchiveHeader(header, reader);
             }
             case HeaderCodeV.RAR5_ARCHIVE_ENCRYPTION_HEADER:
             {
-                var cryptoHeader = ArchiveCryptHeader.Create(header, reader);
+                var cryptoHeader = new ArchiveCryptHeader(header, reader);
                 IsEncrypted = true;
                 _cryptInfo = cryptoHeader.CryptInfo;
 

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

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

src/SharpCompress/Common/Rar/Rar5CryptoInfo.cs

@@ -1,7 +1,5 @@
 using System;
 using System.Security.Cryptography;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common.Rar.Headers;
 using SharpCompress.IO;
 
@@ -9,110 +7,44 @@ namespace SharpCompress.Common.Rar;
 
 internal class Rar5CryptoInfo
 {
-    private Rar5CryptoInfo() { }
+    public Rar5CryptoInfo() { }
 
-    public static Rar5CryptoInfo Create(MarkingBinaryReader reader, bool readInitV)
+    public Rar5CryptoInfo(MarkingBinaryReader reader, bool readInitV)
     {
-        var cryptoInfo = new Rar5CryptoInfo();
         var cryptVersion = reader.ReadRarVIntUInt32();
         if (cryptVersion > EncryptionConstV5.VERSION)
         {
             throw new CryptographicException($"Unsupported crypto version of {cryptVersion}");
         }
         var encryptionFlags = reader.ReadRarVIntUInt32();
-        cryptoInfo.UsePswCheck = FlagUtility.HasFlag(
-            encryptionFlags,
-            EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK
-        );
-        cryptoInfo.LG2Count = reader.ReadRarVIntByte(1);
+        UsePswCheck = FlagUtility.HasFlag(encryptionFlags, EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
+        LG2Count = reader.ReadRarVIntByte(1);
 
-        if (cryptoInfo.LG2Count > EncryptionConstV5.CRYPT5_KDF_LG2_COUNT_MAX)
+        if (LG2Count > EncryptionConstV5.CRYPT5_KDF_LG2_COUNT_MAX)
         {
-            throw new CryptographicException($"Unsupported LG2 count of {cryptoInfo.LG2Count}.");
+            throw new CryptographicException($"Unsupported LG2 count of {LG2Count}.");
         }
 
-        cryptoInfo.Salt = reader.ReadBytes(EncryptionConstV5.SIZE_SALT50);
+        Salt = reader.ReadBytes(EncryptionConstV5.SIZE_SALT50);
 
         if (readInitV) // File header needs to read IV here
         {
-            cryptoInfo.ReadInitV(reader);
+            ReadInitV(reader);
         }
 
-        if (cryptoInfo.UsePswCheck)
+        if (UsePswCheck)
         {
-            cryptoInfo.PswCheck = reader.ReadBytes(EncryptionConstV5.SIZE_PSWCHECK);
+            PswCheck = reader.ReadBytes(EncryptionConstV5.SIZE_PSWCHECK);
             var _pswCheckCsm = reader.ReadBytes(EncryptionConstV5.SIZE_PSWCHECK_CSUM);
 
             var sha = SHA256.Create();
-            cryptoInfo.UsePswCheck = sha.ComputeHash(cryptoInfo.PswCheck)
-                .AsSpan()
-                .StartsWith(_pswCheckCsm.AsSpan());
+            UsePswCheck = sha.ComputeHash(PswCheck).AsSpan().StartsWith(_pswCheckCsm.AsSpan());
         }
-        return cryptoInfo;
-    }
-
-    public static async ValueTask<Rar5CryptoInfo> CreateAsync(
-        AsyncMarkingBinaryReader reader,
-        bool readInitV
-    )
-    {
-        var cryptoInfo = new Rar5CryptoInfo();
-        var cryptVersion = await reader.ReadRarVIntUInt32Async(
-            cancellationToken: CancellationToken.None
-        );
-        if (cryptVersion > EncryptionConstV5.VERSION)
-        {
-            throw new CryptographicException($"Unsupported crypto version of {cryptVersion}");
-        }
-        var encryptionFlags = await reader.ReadRarVIntUInt32Async(
-            cancellationToken: CancellationToken.None
-        );
-        cryptoInfo.UsePswCheck = FlagUtility.HasFlag(
-            encryptionFlags,
-            EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK
-        );
-        cryptoInfo.LG2Count = (int)
-            await reader.ReadRarVIntUInt32Async(cancellationToken: CancellationToken.None);
-        if (cryptoInfo.LG2Count > EncryptionConstV5.CRYPT5_KDF_LG2_COUNT_MAX)
-        {
-            throw new CryptographicException($"Unsupported LG2 count of {cryptoInfo.LG2Count}.");
-        }
-
-        cryptoInfo.Salt = await reader.ReadBytesAsync(
-            EncryptionConstV5.SIZE_SALT50,
-            CancellationToken.None
-        );
-
-        if (readInitV)
-        {
-            await cryptoInfo.ReadInitVAsync(reader);
-        }
-
-        if (cryptoInfo.UsePswCheck)
-        {
-            cryptoInfo.PswCheck = await reader.ReadBytesAsync(
-                EncryptionConstV5.SIZE_PSWCHECK,
-                CancellationToken.None
-            );
-            var _pswCheckCsm = await reader.ReadBytesAsync(
-                EncryptionConstV5.SIZE_PSWCHECK_CSUM,
-                CancellationToken.None
-            );
-
-            var sha = SHA256.Create();
-            cryptoInfo.UsePswCheck = sha.ComputeHash(cryptoInfo.PswCheck)
-                .AsSpan()
-                .StartsWith(_pswCheckCsm.AsSpan());
-        }
-        return cryptoInfo;
     }
 
     public void ReadInitV(MarkingBinaryReader reader) =>
         InitV = reader.ReadBytes(EncryptionConstV5.SIZE_INITV);
 
-    public async ValueTask ReadInitVAsync(AsyncMarkingBinaryReader reader) =>
-        InitV = await reader.ReadBytesAsync(EncryptionConstV5.SIZE_INITV, CancellationToken.None);
-
     public bool UsePswCheck = false;
 
     public int LG2Count = 0;

src/SharpCompress/Common/Rar/RarCryptoBinaryReader.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.Collections.Generic;
 using System.IO;
 using SharpCompress.Common.Rar.Headers;
@@ -7,29 +9,21 @@ namespace SharpCompress.Common.Rar;
 
 internal sealed class RarCryptoBinaryReader : RarCrcBinaryReader
 {
-    private BlockTransformer _rijndael = default!;
+    private BlockTransformer _rijndael;
     private readonly Queue<byte> _data = new();
     private long _readCount;
 
-    private RarCryptoBinaryReader(Stream stream)
-        : base(stream) { }
-
-    public static RarCryptoBinaryReader Create(
-        Stream stream,
-        ICryptKey cryptKey,
-        byte[]? salt = null
-    )
+    public RarCryptoBinaryReader(Stream stream, ICryptKey cryptKey)
+        : base(stream)
     {
-        var binary = new RarCryptoBinaryReader(stream);
-        if (salt == null)
-        {
-            salt = binary.ReadBytesBase(EncryptionConstV5.SIZE_SALT30);
-            binary._readCount += EncryptionConstV5.SIZE_SALT30;
-        }
-        binary._rijndael = new BlockTransformer(cryptKey.Transformer(salt));
-        return binary;
+        var salt = base.ReadBytes(EncryptionConstV5.SIZE_SALT30);
+        _readCount += EncryptionConstV5.SIZE_SALT30;
+        _rijndael = new BlockTransformer(cryptKey.Transformer(salt));
     }
 
+    public RarCryptoBinaryReader(Stream stream, ICryptKey cryptKey, byte[] salt)
+        : base(stream) => _rijndael = new BlockTransformer(cryptKey.Transformer(salt));
+
     // track read count ourselves rather than using the underlying stream since we buffer
     public override long CurrentReadByteCount
     {
@@ -46,8 +40,6 @@ internal sealed class RarCryptoBinaryReader : RarCrcBinaryReader
 
     public override byte[] ReadBytes(int count) => ReadAndDecryptBytes(count);
 
-    private byte[] ReadBytesBase(int count) => base.ReadBytes(count);
-
     private byte[] ReadAndDecryptBytes(int count)
     {
         var queueSize = _data.Count;

src/SharpCompress/Common/Rar/RarVolume.cs

@@ -2,10 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.CompilerServices;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common.Rar.Headers;
 using SharpCompress.IO;
 using SharpCompress.Readers;
@@ -29,8 +26,6 @@ public abstract class RarVolume : Volume
 
     internal abstract IEnumerable<RarFilePart> ReadFileParts();
 
-    internal abstract IAsyncEnumerable<RarFilePart> ReadFilePartsAsync();
-
     internal abstract RarFilePart CreateFilePart(MarkHeader markHeader, FileHeader fileHeader);
 
     internal IEnumerable<RarFilePart> GetVolumeFileParts()
@@ -76,55 +71,6 @@ public abstract class RarVolume : Volume
         }
     }
 
-    internal async IAsyncEnumerable<RarFilePart> GetVolumeFilePartsAsync(
-        [EnumeratorCancellation] CancellationToken cancellationToken = default
-    )
-    {
-        MarkHeader? lastMarkHeader = null;
-        await foreach (
-            var header in _headerFactory
-                .ReadHeadersAsync(Stream)
-                .WithCancellation(cancellationToken)
-        )
-        {
-            switch (header.HeaderType)
-            {
-                case HeaderType.Mark:
-                    {
-                        lastMarkHeader = (MarkHeader)header;
-                    }
-                    break;
-                case HeaderType.Archive:
-                    {
-                        ArchiveHeader = (ArchiveHeader)header;
-                    }
-                    break;
-                case HeaderType.File:
-                    {
-                        var fh = (FileHeader)header;
-                        if (_maxCompressionAlgorithm < fh.CompressionAlgorithm)
-                        {
-                            _maxCompressionAlgorithm = fh.CompressionAlgorithm;
-                        }
-
-                        yield return CreateFilePart(lastMarkHeader!, fh);
-                    }
-                    break;
-                case HeaderType.Service:
-                    {
-                        var fh = (FileHeader)header;
-                        if (fh.FileName == "CMT")
-                        {
-                            var buffer = new byte[fh.CompressedSize];
-                            fh.PackedStream.NotNull().ReadFully(buffer);
-                            Comment = Encoding.UTF8.GetString(buffer, 0, buffer.Length - 1);
-                        }
-                    }
-                    break;
-            }
-        }
-    }
-
     private void EnsureArchiveHeaderLoaded()
     {
         if (ArchiveHeader is null)
@@ -180,12 +126,6 @@ public abstract class RarVolume : Volume
         }
     }
 
-    public async ValueTask<bool> IsSolidArchiveAsync(CancellationToken cancellationToken = default)
-    {
-        await EnsureArchiveHeaderLoadedAsync(cancellationToken);
-        return ArchiveHeader?.IsSolid ?? false;
-    }
-
     public int MinVersion
     {
         get
@@ -234,68 +174,5 @@ public abstract class RarVolume : Volume
         }
     }
 
-    private async ValueTask EnsureArchiveHeaderLoadedAsync(CancellationToken cancellationToken)
-    {
-        if (ArchiveHeader is null)
-        {
-            if (Mode == StreamingMode.Streaming)
-            {
-                throw new InvalidOperationException(
-                    "ArchiveHeader should never been null in a streaming read."
-                );
-            }
-
-            // we only want to load the archive header to avoid overhead but have to do the nasty thing and reset the stream
-            await GetVolumeFilePartsAsync(cancellationToken).FirstAsync();
-            Stream.Position = 0;
-        }
-    }
-
-    public virtual async ValueTask<int> MinVersionAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        await EnsureArchiveHeaderLoadedAsync(cancellationToken).ConfigureAwait(false);
-        if (_maxCompressionAlgorithm >= 50)
-        {
-            return 5; //5-6
-        }
-        else if (_maxCompressionAlgorithm >= 29)
-        {
-            return 3; //3-4
-        }
-        else if (_maxCompressionAlgorithm >= 20)
-        {
-            return 2; //2
-        }
-        else
-        {
-            return 1;
-        }
-    }
-
-    public virtual async ValueTask<int> MaxVersionAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        await EnsureArchiveHeaderLoadedAsync(cancellationToken).ConfigureAwait(false);
-        if (_maxCompressionAlgorithm >= 50)
-        {
-            return 6; //5-6
-        }
-        else if (_maxCompressionAlgorithm >= 29)
-        {
-            return 4; //3-4
-        }
-        else if (_maxCompressionAlgorithm >= 20)
-        {
-            return 2; //2
-        }
-        else
-        {
-            return 1;
-        }
-    }
-
     public string? Comment { get; internal set; }
 }

src/SharpCompress/Common/SevenZip/ArchiveDatabase.Async.cs

@@ -1,40 +0,0 @@
-#nullable disable
-
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Compressors.LZMA;
-using SharpCompress.Compressors.LZMA.Utilites;
-
-namespace SharpCompress.Common.SevenZip;
-
-internal sealed partial class ArchiveDatabase
-{
-    internal async ValueTask<Stream> GetFolderStreamAsync(
-        Stream stream,
-        CFolder folder,
-        IPasswordProvider pw,
-        CancellationToken cancellationToken
-    )
-    {
-        var packStreamIndex = folder._firstPackStreamId;
-        var folderStartPackPos = GetFolderStreamPos(folder, 0);
-        var count = folder._packStreams.Count;
-        var packSizes = new long[count];
-        for (var j = 0; j < count; j++)
-        {
-            packSizes[j] = _packSizes[packStreamIndex + j];
-        }
-
-        return await DecoderStreamHelper
-            .CreateDecoderStreamAsync(
-                stream,
-                folderStartPackPos,
-                packSizes,
-                folder,
-                pw,
-                cancellationToken
-            )
-            .ConfigureAwait(false);
-    }
-}

src/SharpCompress/Common/SevenZip/ArchiveDatabase.cs

@@ -1,4 +1,4 @@
-#nullable disable
+#nullable disable
 
 using System;
 using System.Collections.Generic;
@@ -8,7 +8,7 @@ using SharpCompress.Compressors.LZMA.Utilites;
 
 namespace SharpCompress.Common.SevenZip;
 
-internal partial class ArchiveDatabase
+internal class ArchiveDatabase
 {
     internal byte _majorVersion;
     internal byte _minorVersion;

src/SharpCompress/Common/SevenZip/ArchiveReader.Async.cs

@@ -1,580 +0,0 @@
-#nullable disable
-
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Compressors.LZMA;
-using SharpCompress.Compressors.LZMA.Utilites;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common.SevenZip;
-
-internal sealed partial class ArchiveReader
-{
-    public async ValueTask OpenAsync(
-        Stream stream,
-        bool lookForHeader,
-        CancellationToken cancellationToken = default
-    )
-    {
-        Close();
-
-        _streamOrigin = stream.Position;
-        _streamEnding = stream.Length;
-
-        var canScan = lookForHeader ? 0x80000 - 20 : 0;
-        while (true)
-        {
-            // TODO: Check Signature!
-            _header = new byte[0x20];
-            await stream.ReadExactAsync(_header, 0, 0x20, cancellationToken);
-
-            if (
-                !lookForHeader
-                || _header
-                    .AsSpan(0, length: 6)
-                    .SequenceEqual<byte>([0x37, 0x7A, 0xBC, 0xAF, 0x27, 0x1C])
-            )
-            {
-                break;
-            }
-
-            if (canScan == 0)
-            {
-                throw new InvalidFormatException("Unable to find 7z signature");
-            }
-
-            canScan--;
-            stream.Position = ++_streamOrigin;
-        }
-
-        _stream = stream;
-    }
-
-    public async ValueTask<ArchiveDatabase> ReadDatabaseAsync(
-        IPasswordProvider pass,
-        CancellationToken cancellationToken = default
-    )
-    {
-        var db = new ArchiveDatabase(pass);
-        db.Clear();
-
-        db._majorVersion = _header[6];
-        db._minorVersion = _header[7];
-
-        if (db._majorVersion != 0)
-        {
-            throw new InvalidOperationException();
-        }
-
-        var crcFromArchive = DataReader.Get32(_header, 8);
-        var nextHeaderOffset = (long)DataReader.Get64(_header, 0xC);
-        var nextHeaderSize = (long)DataReader.Get64(_header, 0x14);
-        var nextHeaderCrc = DataReader.Get32(_header, 0x1C);
-
-        var crc = Crc.INIT_CRC;
-        crc = Crc.Update(crc, nextHeaderOffset);
-        crc = Crc.Update(crc, nextHeaderSize);
-        crc = Crc.Update(crc, nextHeaderCrc);
-        crc = Crc.Finish(crc);
-
-        if (crc != crcFromArchive)
-        {
-            throw new InvalidOperationException();
-        }
-
-        db._startPositionAfterHeader = _streamOrigin + 0x20;
-
-        // empty header is ok
-        if (nextHeaderSize == 0)
-        {
-            db.Fill();
-            return db;
-        }
-
-        if (nextHeaderOffset < 0 || nextHeaderSize < 0 || nextHeaderSize > int.MaxValue)
-        {
-            throw new InvalidOperationException();
-        }
-
-        if (nextHeaderOffset > _streamEnding - db._startPositionAfterHeader)
-        {
-            throw new InvalidOperationException("nextHeaderOffset is invalid");
-        }
-
-        _stream.Seek(nextHeaderOffset, SeekOrigin.Current);
-
-        var header = new byte[nextHeaderSize];
-        await _stream.ReadExactAsync(header, 0, header.Length, cancellationToken);
-
-        if (Crc.Finish(Crc.Update(Crc.INIT_CRC, header, 0, header.Length)) != nextHeaderCrc)
-        {
-            throw new InvalidOperationException();
-        }
-
-        using (var streamSwitch = new CStreamSwitch())
-        {
-            streamSwitch.Set(this, header);
-
-            var type = ReadId();
-            if (type != BlockType.Header)
-            {
-                if (type != BlockType.EncodedHeader)
-                {
-                    throw new InvalidOperationException();
-                }
-
-                var dataVector = await ReadAndDecodePackedStreamsAsync(
-                        db._startPositionAfterHeader,
-                        db.PasswordProvider,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-
-                // compressed header without content is odd but ok
-                if (dataVector.Count == 0)
-                {
-                    db.Fill();
-                    return db;
-                }
-
-                if (dataVector.Count != 1)
-                {
-                    throw new InvalidOperationException();
-                }
-
-                streamSwitch.Set(this, dataVector[0]);
-
-                if (ReadId() != BlockType.Header)
-                {
-                    throw new InvalidOperationException();
-                }
-            }
-
-            await ReadHeaderAsync(db, db.PasswordProvider, cancellationToken).ConfigureAwait(false);
-        }
-        db.Fill();
-        return db;
-    }
-
-    private async ValueTask<List<byte[]>> ReadAndDecodePackedStreamsAsync(
-        long baseOffset,
-        IPasswordProvider pass,
-        CancellationToken cancellationToken
-    )
-    {
-#if DEBUG
-        Log.WriteLine("-- ReadAndDecodePackedStreamsAsync --");
-        Log.PushIndent();
-#endif
-        try
-        {
-            ReadStreamsInfo(
-                null,
-                out var dataStartPos,
-                out var packSizes,
-                out var packCrCs,
-                out var folders,
-                out var numUnpackStreamsInFolders,
-                out var unpackSizes,
-                out var digests
-            );
-
-            dataStartPos += baseOffset;
-
-            var dataVector = new List<byte[]>(folders.Count);
-            var packIndex = 0;
-            foreach (var folder in folders)
-            {
-                var oldDataStartPos = dataStartPos;
-                var myPackSizes = new long[folder._packStreams.Count];
-                for (var i = 0; i < myPackSizes.Length; i++)
-                {
-                    var packSize = packSizes[packIndex + i];
-                    myPackSizes[i] = packSize;
-                    dataStartPos += packSize;
-                }
-
-                var outStream = await DecoderStreamHelper
-                    .CreateDecoderStreamAsync(
-                        _stream,
-                        oldDataStartPos,
-                        myPackSizes,
-                        folder,
-                        pass,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-
-                var unpackSize = checked((int)folder.GetUnpackSize());
-                var data = new byte[unpackSize];
-                await outStream
-                    .ReadExactAsync(data, 0, data.Length, cancellationToken)
-                    .ConfigureAwait(false);
-                if (outStream.ReadByte() >= 0)
-                {
-                    throw new InvalidFormatException("Decoded stream is longer than expected.");
-                }
-                dataVector.Add(data);
-
-                if (folder.UnpackCrcDefined)
-                {
-                    if (
-                        Crc.Finish(Crc.Update(Crc.INIT_CRC, data, 0, unpackSize))
-                        != folder._unpackCrc
-                    )
-                    {
-                        throw new InvalidFormatException(
-                            "Decoded stream does not match expected CRC."
-                        );
-                    }
-                }
-            }
-            return dataVector;
-        }
-        finally
-        {
-#if DEBUG
-            Log.PopIndent();
-#endif
-        }
-    }
-
-    private async ValueTask ReadHeaderAsync(
-        ArchiveDatabase db,
-        IPasswordProvider getTextPassword,
-        CancellationToken cancellationToken
-    )
-    {
-#if DEBUG
-        Log.WriteLine("-- ReadHeaderAsync --");
-        Log.PushIndent();
-#endif
-        try
-        {
-            var type = ReadId();
-
-            if (type == BlockType.ArchiveProperties)
-            {
-                ReadArchiveProperties();
-                type = ReadId();
-            }
-
-            List<byte[]> dataVector = null;
-            if (type == BlockType.AdditionalStreamsInfo)
-            {
-                dataVector = await ReadAndDecodePackedStreamsAsync(
-                        db._startPositionAfterHeader,
-                        getTextPassword,
-                        cancellationToken
-                    )
-                    .ConfigureAwait(false);
-                type = ReadId();
-            }
-
-            List<long> unpackSizes;
-            List<uint?> digests;
-
-            if (type == BlockType.MainStreamsInfo)
-            {
-                ReadStreamsInfo(
-                    dataVector,
-                    out db._dataStartPosition,
-                    out db._packSizes,
-                    out db._packCrCs,
-                    out db._folders,
-                    out db._numUnpackStreamsVector,
-                    out unpackSizes,
-                    out digests
-                );
-
-                db._dataStartPosition += db._startPositionAfterHeader;
-                type = ReadId();
-            }
-            else
-            {
-                unpackSizes = new List<long>(db._folders.Count);
-                digests = new List<uint?>(db._folders.Count);
-                db._numUnpackStreamsVector = new List<int>(db._folders.Count);
-                for (var i = 0; i < db._folders.Count; i++)
-                {
-                    var folder = db._folders[i];
-                    unpackSizes.Add(folder.GetUnpackSize());
-                    digests.Add(folder._unpackCrc);
-                    db._numUnpackStreamsVector.Add(1);
-                }
-            }
-
-            db._files.Clear();
-
-            if (type == BlockType.End)
-            {
-                return;
-            }
-
-            if (type != BlockType.FilesInfo)
-            {
-                throw new InvalidOperationException();
-            }
-
-            var numFiles = ReadNum();
-#if DEBUG
-            Log.WriteLine("NumFiles: " + numFiles);
-#endif
-            db._files = new List<CFileItem>(numFiles);
-            for (var i = 0; i < numFiles; i++)
-            {
-                db._files.Add(new CFileItem());
-            }
-
-            var emptyStreamVector = new BitVector(numFiles);
-            BitVector emptyFileVector = null;
-            BitVector antiFileVector = null;
-            var numEmptyStreams = 0;
-
-            for (; ; )
-            {
-                type = ReadId();
-                if (type == BlockType.End)
-                {
-                    break;
-                }
-
-                var size = checked((long)ReadNumber());
-                var oldPos = _currentReader.Offset;
-                switch (type)
-                {
-                    case BlockType.Name:
-                        using (var streamSwitch = new CStreamSwitch())
-                        {
-                            streamSwitch.Set(this, dataVector);
-#if DEBUG
-                            Log.Write("FileNames:");
-#endif
-                            for (var i = 0; i < db._files.Count; i++)
-                            {
-                                db._files[i].Name = _currentReader.ReadString();
-#if DEBUG
-                                Log.Write("  " + db._files[i].Name);
-#endif
-                            }
-#if DEBUG
-                            Log.WriteLine();
-#endif
-                        }
-                        break;
-                    case BlockType.WinAttributes:
-#if DEBUG
-                        Log.Write("WinAttributes:");
-#endif
-                        ReadAttributeVector(
-                            dataVector,
-                            numFiles,
-                            delegate(int i, uint? attr)
-                            {
-                                db._files[i].ExtendedAttrib = attr;
-
-                                if (attr.HasValue && (attr.Value >> 16) != 0)
-                                {
-                                    attr = attr.Value & 0x7FFFu;
-                                }
-
-                                db._files[i].Attrib = attr;
-#if DEBUG
-                                Log.Write(
-                                    "  " + (attr.HasValue ? attr.Value.ToString("x8") : "n/a")
-                                );
-#endif
-                            }
-                        );
-#if DEBUG
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.EmptyStream:
-                        emptyStreamVector = ReadBitVector(numFiles);
-#if DEBUG
-
-                        Log.Write("EmptyStream: ");
-#endif
-                        for (var i = 0; i < emptyStreamVector.Length; i++)
-                        {
-                            if (emptyStreamVector[i])
-                            {
-#if DEBUG
-                                Log.Write("x");
-#endif
-                                numEmptyStreams++;
-                            }
-                            else
-                            {
-#if DEBUG
-                                Log.Write(".");
-#endif
-                            }
-                        }
-#if DEBUG
-                        Log.WriteLine();
-#endif
-
-                        emptyFileVector = new BitVector(numEmptyStreams);
-                        antiFileVector = new BitVector(numEmptyStreams);
-                        break;
-                    case BlockType.EmptyFile:
-                        emptyFileVector = ReadBitVector(numEmptyStreams);
-#if DEBUG
-                        Log.Write("EmptyFile: ");
-                        for (var i = 0; i < numEmptyStreams; i++)
-                        {
-                            Log.Write(emptyFileVector[i] ? "x" : ".");
-                        }
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.Anti:
-                        antiFileVector = ReadBitVector(numEmptyStreams);
-#if DEBUG
-                        Log.Write("Anti: ");
-                        for (var i = 0; i < numEmptyStreams; i++)
-                        {
-                            Log.Write(antiFileVector[i] ? "x" : ".");
-                        }
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.StartPos:
-#if DEBUG
-                        Log.Write("StartPos:");
-#endif
-                        ReadNumberVector(
-                            dataVector,
-                            numFiles,
-                            delegate(int i, long? startPos)
-                            {
-                                db._files[i].StartPos = startPos;
-#if DEBUG
-                                Log.Write(
-                                    "  " + (startPos.HasValue ? startPos.Value.ToString() : "n/a")
-                                );
-#endif
-                            }
-                        );
-#if DEBUG
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.CTime:
-#if DEBUG
-                        Log.Write("CTime:");
-#endif
-                        ReadDateTimeVector(
-                            dataVector,
-                            numFiles,
-                            delegate(int i, DateTime? time)
-                            {
-                                db._files[i].CTime = time;
-#if DEBUG
-                                Log.Write("  " + (time.HasValue ? time.Value.ToString() : "n/a"));
-#endif
-                            }
-                        );
-#if DEBUG
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.ATime:
-#if DEBUG
-                        Log.Write("ATime:");
-#endif
-                        ReadDateTimeVector(
-                            dataVector,
-                            numFiles,
-                            delegate(int i, DateTime? time)
-                            {
-                                db._files[i].ATime = time;
-#if DEBUG
-                                Log.Write("  " + (time.HasValue ? time.Value.ToString() : "n/a"));
-#endif
-                            }
-                        );
-#if DEBUG
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.MTime:
-#if DEBUG
-                        Log.Write("MTime:");
-#endif
-                        ReadDateTimeVector(
-                            dataVector,
-                            numFiles,
-                            delegate(int i, DateTime? time)
-                            {
-                                db._files[i].MTime = time;
-#if DEBUG
-                                Log.Write("  " + (time.HasValue ? time.Value.ToString() : "n/a"));
-#endif
-                            }
-                        );
-#if DEBUG
-                        Log.WriteLine();
-#endif
-                        break;
-                    case BlockType.Dummy:
-#if DEBUG
-                        Log.Write("Dummy: " + size);
-#endif
-                        for (long j = 0; j < size; j++)
-                        {
-                            if (ReadByte() != 0)
-                            {
-                                throw new InvalidOperationException();
-                            }
-                        }
-                        break;
-                    default:
-                        SkipData(size);
-                        break;
-                }
-
-                var checkRecordsSize = (db._majorVersion > 0 || db._minorVersion > 2);
-                if (checkRecordsSize && _currentReader.Offset - oldPos != size)
-                {
-                    throw new InvalidOperationException();
-                }
-            }
-
-            var emptyFileIndex = 0;
-            var sizeIndex = 0;
-            for (var i = 0; i < numFiles; i++)
-            {
-                var file = db._files[i];
-                file.HasStream = !emptyStreamVector[i];
-                if (file.HasStream)
-                {
-                    file.IsDir = false;
-                    file.IsAnti = false;
-                    file.Size = unpackSizes[sizeIndex];
-                    file.Crc = digests[sizeIndex];
-                    sizeIndex++;
-                }
-                else
-                {
-                    file.IsDir = !emptyFileVector[emptyFileIndex];
-                    file.IsAnti = antiFileVector[emptyFileIndex];
-                    emptyFileIndex++;
-                    file.Size = 0;
-                    file.Crc = null;
-                }
-            }
-        }
-        finally
-        {
-#if DEBUG
-            Log.PopIndent();
-#endif
-        }
-    }
-}

src/SharpCompress/Common/SevenZip/ArchiveReader.cs

@@ -5,15 +5,13 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Compressors.LZMA;
 using SharpCompress.Compressors.LZMA.Utilites;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.SevenZip;
 
-internal partial class ArchiveReader
+internal class ArchiveReader
 {
     internal Stream _stream;
     internal Stack<DataReader> _readerStack = new();
@@ -1272,8 +1270,6 @@ internal partial class ArchiveReader
         _stream = stream;
     }
 
-    // OpenAsync moved to ArchiveReader.Async.cs
-
     public void Close()
     {
         _stream?.Dispose();
@@ -1387,8 +1383,6 @@ internal partial class ArchiveReader
         return db;
     }
 
-    // ReadDatabaseAsync moved to ArchiveReader.Async.cs
-
     internal class CExtractFolderInfo
     {
         internal int _fileIndex;

src/SharpCompress/Common/SevenZip/SevenZipFilePart.cs

@@ -1,7 +1,5 @@
 using System.IO;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.SevenZip;
@@ -60,35 +58,6 @@ internal class SevenZipFilePart : FilePart
         return new ReadOnlySubStream(folderStream, Header.Size, leaveOpen: false);
     }
 
-    internal override async ValueTask<Stream?> GetCompressedStreamAsync(
-        CancellationToken cancellationToken = default
-    )
-    {
-        if (!Header.HasStream)
-        {
-            return Stream.Null;
-        }
-        var folderStream = await _database.GetFolderStreamAsync(
-            _stream,
-            Folder!,
-            _database.PasswordProvider,
-            cancellationToken
-        );
-
-        var firstFileIndex = _database._folderStartFileIndex[_database._folders.IndexOf(Folder!)];
-        var skipCount = Index - firstFileIndex;
-        long skipSize = 0;
-        for (var i = 0; i < skipCount; i++)
-        {
-            skipSize += _database._files[firstFileIndex + i].Size;
-        }
-        if (skipSize > 0)
-        {
-            await folderStream.SkipAsync(skipSize, cancellationToken);
-        }
-        return new ReadOnlySubStream(folderStream, Header.Size, leaveOpen: false);
-    }
-
     public CompressionType CompressionType
     {
         get