Merge pull request #1184 from adamhathcock/adam/cleanup

Some clean up post-async merging

.copilot-agent.yml

@@ -1,7 +0,0 @@
-enabled: true
-agent:
-  name: copilot-coding-agent
-  allow:
-    - paths: ["src/**/*", "tests/**/*", "README.md", "AGENTS.md"]
-      actions: ["create", "modify"]
-  require_review_before_merge: true

.github/agents/copilot-agent.yml

@@ -1,17 +0,0 @@
-enabled: true
-agent:
-  name: copilot-coding-agent
-  allow:
-    - paths: ["src/**/*", "tests/**/*", "README.md", "AGENTS.md"]
-      actions: ["create", "modify", "delete"]
-  require_review_before_merge: true
-  required_approvals: 1
-  allowed_merge_strategies:
-    - squash
-    - merge
-  auto_merge_on_green: false
-  run_workflows: true
-notes: |
-  - This manifest expresses the policy for the Copilot coding agent in this repository.
-  - It does NOT install or authorize the agent; a repository admin must install the Copilot coding agent app and grant the repository the necessary permissions (contents: write, pull_requests: write, checks: write, actions: write/read, issues: write) to allow the agent to act.
-  - Keep allow paths narrow and prefer require_review_before_merge during initial rollout.

.github/prompts/plan-async.prompt.md

@@ -1,25 +0,0 @@
-# Plan: Implement Missing Async Functionality in SharpCompress
-
-SharpCompress has async support for low-level stream operations and Reader/Writer APIs, but critical entry points (Archive.Open, factory methods, initialization) remain synchronous. This plan adds async overloads for all user-facing I/O operations and fixes existing async bugs, enabling full end-to-end async workflows.
-
-## Steps
-
-1. **Add async factory methods** to [ArchiveFactory.cs](src/SharpCompress/Factories/ArchiveFactory.cs), [ReaderFactory.cs](src/SharpCompress/Factories/ReaderFactory.cs), and [WriterFactory.cs](src/SharpCompress/Factories/WriterFactory.cs) with `OpenAsync` and `CreateAsync` overloads accepting `CancellationToken`
-
-2. **Implement async Open methods** on concrete archive types ([ZipArchive.cs](src/SharpCompress/Archives/Zip/ZipArchive.cs), [TarArchive.cs](src/SharpCompress/Archives/Tar/TarArchive.cs), [RarArchive.cs](src/SharpCompress/Archives/Rar/RarArchive.cs), [GZipArchive.cs](src/SharpCompress/Archives/GZip/GZipArchive.cs), [SevenZipArchive.cs](src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs)) and reader types ([ZipReader.cs](src/SharpCompress/Readers/Zip/ZipReader.cs), [TarReader.cs](src/SharpCompress/Readers/Tar/TarReader.cs), etc.)
-
-3. **Convert archive initialization logic to async** including header reading, volume loading, and format signature detection across archive constructors and internal initialization methods
-
-4. **Fix LZMA decoder async bugs** in [LzmaStream.cs](src/SharpCompress/Compressors/LZMA/LzmaStream.cs), [Decoder.cs](src/SharpCompress/Compressors/LZMA/Decoder.cs), and [OutWindow.cs](src/SharpCompress/Compressors/LZMA/OutWindow.cs) to enable true async 7Zip support and remove `NonDisposingStream` workaround
-
-5. **Complete Rar async implementation** by converting `UnpackV2017` methods to async in [UnpackV2017.cs](src/SharpCompress/Compressors/Rar/UnpackV2017.cs) and updating Rar20 decompression
-
-6. **Add comprehensive async tests** covering all new async entry points, cancellation scenarios, and concurrent operations across all archive formats in test files
-
-## Further Considerations
-
-1. **Breaking changes** - Should new async methods be added alongside existing sync methods (non-breaking), or should sync methods eventually be deprecated? Recommend additive approach for backward compatibility.
-
-2. **Performance impact** - Header parsing for formats like Zip/Tar is often small; consider whether truly async parsing adds value vs sync parsing wrapped in Task, or make it conditional based on stream type (network vs file).
-
-3. **7Zip complexity** - The LZMA async bug fix (Step 4) may be challenging due to state management in the decoder; consider whether to scope it separately or implement a simpler workaround that maintains correctness.

.github/prompts/plan-for-next.prompt.md

@@ -1,123 +0,0 @@
-# Plan: Modernize SharpCompress Public API
-
-Based on comprehensive analysis, the API has several inconsistencies around factory patterns, async support, format capabilities, and options classes. Most improvements can be done incrementally without breaking changes.
-
-## Steps
-
-1. **Standardize factory patterns** by deprecating format-specific static `Open` methods in [Archives/Zip/ZipArchive.cs](src/SharpCompress/Archives/Zip/ZipArchive.cs), [Archives/Tar/TarArchive.cs](src/SharpCompress/Archives/Tar/TarArchive.cs), etc. in favor of centralized [Factories/ArchiveFactory.cs](src/SharpCompress/Factories/ArchiveFactory.cs)
-
-2. **Complete async implementation** in [Writers/Zip/ZipWriter.cs](src/SharpCompress/Writers/Zip/ZipWriter.cs) and other writers that currently use sync-over-async, implementing true async I/O throughout the writer hierarchy
-
-3. **Unify options classes** by making [Common/ExtractionOptions.cs](src/SharpCompress/Common/ExtractionOptions.cs) inherit from `OptionsBase` and adding progress reporting to extraction methods consistently
-
-4. **Clarify GZip semantics** in [Archives/GZip/GZipArchive.cs](src/SharpCompress/Archives/GZip/GZipArchive.cs) by adding XML documentation explaining single-entry limitation and relationship to GZip compression used in Tar.gz
-
-## Further Considerations
-
-1. **Breaking changes roadmap** - Should we plan a major version (2.0) to remove deprecated factory methods, clean up `ArchiveType` enum (remove Arc/Arj or add full support), and consolidate naming patterns?
-
-2. **Progress reporting consistency** - Should `IProgress<ArchiveExtractionProgress<IEntry>>` be added to all extraction extension methods or consolidated into options classes?
-
-## Detailed Analysis
-
-### Factory Pattern Issues
-
-Three different factory patterns exist with overlapping functionality:
-
-1. **Static Factories**: ArchiveFactory, ReaderFactory, WriterFactory
-2. **Instance Factories**: IArchiveFactory, IReaderFactory, IWriterFactory
-3. **Format-specific static methods**: Each archive class has static `Open` methods
-
-**Example confusion:**
-```csharp
-// Three ways to open a Zip archive - which is recommended?
-var archive1 = ArchiveFactory.Open("file.zip");
-var archive2 = ZipArchive.Open("file.zip");
-var archive3 = ArchiveFactory.AutoFactory.Open(fileInfo, options);
-```
-
-### Async Support Gaps
-
-Base `IWriter` interface has async methods, but writer implementations provide minimal async support. Most writers just call synchronous methods:
-
-```csharp
-public virtual async Task WriteAsync(...)
-{
-    // Default implementation calls synchronous version
-    Write(filename, source, modificationTime);
-    await Task.CompletedTask.ConfigureAwait(false);
-}
-```
-
-Real async implementations only in:
-- `TarWriter` - Proper async implementation
-- Most other writers use sync-over-async
-
-### GZip Archive Special Case
-
-GZip is treated as both a compression format and an archive format, but only supports single-entry archives:
-
-```csharp
-protected override GZipArchiveEntry CreateEntryInternal(...)
-{
-    if (Entries.Any())
-    {
-        throw new InvalidFormatException("Only one entry is allowed in a GZip Archive");
-    }
-    // ...
-}
-```
-
-### Options Class Hierarchy
-
-```
-OptionsBase (LeaveStreamOpen, ArchiveEncoding)
-  ├─ ReaderOptions (LookForHeader, Password, DisableCheckIncomplete, BufferSize, ExtensionHint, Progress)
-  ├─ WriterOptions (CompressionType, CompressionLevel, Progress)
-  │   ├─ ZipWriterOptions (ArchiveComment, UseZip64)
-  │   ├─ TarWriterOptions (FinalizeArchiveOnClose, HeaderFormat)
-  │   └─ GZipWriterOptions (no additional properties)
-  └─ ExtractionOptions (standalone - Overwrite, ExtractFullPath, PreserveFileTime, PreserveAttributes)
-```
-
-**Issues:**
-- `ExtractionOptions` doesn't inherit from `OptionsBase` - no encoding support during extraction
-- Progress reporting inconsistency between readers and extraction
-- Obsolete properties (`ChecksumIsValid`, `Version`) with unclear migration path
-
-### Implementation Priorities
-
-**High Priority (Non-Breaking):**
-1. Add API usage guide (Archive vs Reader, factory recommendations, async best practices)
-2. Fix progress reporting consistency
-3. Complete async implementation in writers
-
-**Medium Priority (Next Major Version):**
-1. Unify factory pattern - deprecate format-specific static `Open` methods
-2. Clean up options classes - make `ExtractionOptions` inherit from `OptionsBase`
-3. Clarify archive types - remove Arc/Arj from `ArchiveType` enum or add full support
-4. Standardize naming across archive types
-
-**Low Priority:**
-1. Add BZip2 archive support similar to GZipArchive
-2. Complete obsolete property cleanup with migration guide
-
-### Backward Compatibility Strategy
-
-**Safe (Non-Breaking) Changes:**
-- Add new methods to interfaces (use default implementations)
-- Add new options properties (with defaults)
-- Add new factory methods
-- Improve async implementations
-- Add progress reporting support
-
-**Breaking Changes to Avoid:**
-- ❌ Removing format-specific `Open` methods (deprecate instead)
-- ❌ Changing `LeaveStreamOpen` default (currently `true`)
-- ❌ Removing obsolete properties before major version bump
-- ❌ Changing return types or signatures of existing methods
-
-**Deprecation Pattern:**
-- Use `[Obsolete]` for one major version
-- Use `[EditorBrowsable(EditorBrowsableState.Never)]` in next major version
-- Remove in following major version

AGENTS.md

@@ -179,3 +179,58 @@ 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

@@ -3,18 +3,17 @@
     <PackageVersion Include="Bullseye" Version="6.1.0" />
     <PackageVersion Include="AwesomeAssertions" Version="9.3.0" />
     <PackageVersion Include="Glob" Version="1.1.9" />
-    <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.15" />
+    <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.16" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.0" />
-    <PackageVersion Include="Microsoft.NET.ILLink.Task" Version="10.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Mono.Posix.NETStandard" Version="1.0.0" />
     <PackageVersion Include="SimpleExec" Version="13.0.0" />
     <PackageVersion Include="System.Text.Encoding.CodePages" Version="10.0.0" />
     <PackageVersion Include="System.Buffers" Version="4.6.1" />
     <PackageVersion Include="System.Memory" Version="4.6.3" />
-    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.v3" Version="3.2.2" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
-    <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="10.0.102" />
     <GlobalPackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3" />
     <GlobalPackageReference
       Include="Microsoft.VisualStudio.Threading.Analyzers"

build/Program.cs

@@ -230,7 +230,7 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
     }
     else
     {
-        // Not tagged - create prerelease version based on next minor version
+        // Not tagged - create prerelease version
         var allTags = (await GetGitOutput("tag", "--list"))
             .Split('\n', StringSplitOptions.RemoveEmptyEntries)
             .Where(tag => Regex.IsMatch(tag.Trim(), @"^\d+\.\d+\.\d+$"))
@@ -240,8 +240,22 @@ 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);
 
-        // Increment minor version for next release
-        var nextVersion = new Version(lastVersion.Major, lastVersion.Minor + 1, 0);
+        // 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)");
+        }
 
         // 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";
@@ -253,6 +267,28 @@ 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

build/packages.lock.json

@@ -25,12 +25,12 @@
       },
       "Microsoft.SourceLink.GitHub": {
         "type": "Direct",
-        "requested": "[8.0.0, )",
-        "resolved": "8.0.0",
-        "contentHash": "G5q7OqtwIyGTkeIOAc3u2ZuV/kicQaec5EaRnc0pIeSnh9LUjj+PYQrJYBURvDt7twGl2PKA7nSN0kz1Zw5bnQ==",
+        "requested": "[10.0.102, )",
+        "resolved": "10.0.102",
+        "contentHash": "Oxq3RCIJSdtpIU4hLqO7XaDe/Ra3HS9Wi8rJl838SAg6Zu1iQjerA0+xXWBgUFYbgknUGCLOU0T+lzMLkvY9Qg==",
         "dependencies": {
-          "Microsoft.Build.Tasks.Git": "8.0.0",
-          "Microsoft.SourceLink.Common": "8.0.0"
+          "Microsoft.Build.Tasks.Git": "10.0.102",
+          "Microsoft.SourceLink.Common": "10.0.102"
         }
       },
       "Microsoft.VisualStudio.Threading.Analyzers": {
@@ -47,8 +47,8 @@
       },
       "Microsoft.Build.Tasks.Git": {
         "type": "Transitive",
-        "resolved": "8.0.0",
-        "contentHash": "bZKfSIKJRXLTuSzLudMFte/8CempWjVamNUR5eHJizsy+iuOuO/k2gnh7W0dHJmYY0tBf+gUErfluCv5mySAOQ=="
+        "resolved": "10.0.102",
+        "contentHash": "0i81LYX31U6UiXz4NOLbvc++u+/mVDmOt+PskrM/MygpDxkv9THKQyRUmavBpLK6iBV0abNWnn+CQgSRz//Pwg=="
       },
       "Microsoft.NETFramework.ReferenceAssemblies.net461": {
         "type": "Transitive",
@@ -57,8 +57,8 @@
       },
       "Microsoft.SourceLink.Common": {
         "type": "Transitive",
-        "resolved": "8.0.0",
-        "contentHash": "dk9JPxTCIevS75HyEQ0E4OVAFhB2N+V9ShCXf8Q6FkUQZDkgLI12y679Nym1YqsiSysuQskT7Z+6nUf3yab6Vw=="
+        "resolved": "10.0.102",
+        "contentHash": "Mk1IMb9q5tahC2NltxYXFkLBtuBvfBoCQ3pIxYQWfzbCE9o1OB9SsHe0hnNGo7lWgTA/ePbFAJLWu6nLL9K17A=="
       }
     }
   }

src/SharpCompress/Archives/AbstractArchive.Async.cs

@@ -0,0 +1,103 @@
+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 class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
+public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     where TEntry : IArchiveEntry
     where TVolume : IVolume
 {
@@ -16,6 +16,10 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     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)
@@ -77,16 +81,6 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     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>();
@@ -145,19 +139,6 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     /// </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>
@@ -169,85 +150,4 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
             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

@@ -0,0 +1,123 @@
+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 class AbstractWritableArchive<TEntry, TVolume>
+public abstract partial class AbstractWritableArchive<TEntry, TVolume>
     : AbstractArchive<TEntry, TVolume>,
         IWritableArchive,
         IWritableAsyncArchive
@@ -84,12 +84,12 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         }
     }
 
-    void IWritableArchiveCommon.RemoveEntry(IArchiveEntry entry) => RemoveEntry((TEntry)entry);
+    void IWritableArchive.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 IWritableArchiveCommon.AddEntry(
+    IArchiveEntry IWritableArchive.AddEntry(
         string key,
         Stream source,
         bool closeStream,
@@ -97,7 +97,7 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         DateTime? modified
     ) => AddEntry(key, source, closeStream, size, modified);
 
-    IArchiveEntry IWritableArchiveCommon.AddDirectoryEntry(string key, DateTime? modified) =>
+    IArchiveEntry IWritableArchive.AddDirectoryEntry(string key, DateTime? modified) =>
         AddDirectoryEntry(key, modified);
 
     public TEntry AddEntry(
@@ -140,6 +140,24 @@ public abstract 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 '\\')
@@ -163,18 +181,6 @@ public abstract 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,
@@ -212,7 +218,7 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
     protected abstract ValueTask SaveToAsync(
         Stream stream,
         WriterOptions options,
-        IEnumerable<TEntry> oldEntries,
+        IAsyncEnumerable<TEntry> oldEntries,
         IEnumerable<TEntry> newEntries,
         CancellationToken cancellationToken = default
     );

src/SharpCompress/Archives/ArchiveFactory.Async.cs

@@ -0,0 +1,157 @@
+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();
+        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

@@ -11,27 +11,14 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public static class ArchiveFactory
+public static partial class ArchiveFactory
 {
     public static IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null)
     {
         readerOptions ??= new ReaderOptions();
-        stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
         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
@@ -52,16 +39,6 @@ public static 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 };
@@ -69,18 +46,6 @@ public static 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
@@ -105,32 +70,6 @@ public static 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));
@@ -152,33 +91,6 @@ public static 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,
@@ -189,7 +101,15 @@ public static class ArchiveFactory
         archive.WriteToDirectory(destinationDirectory, options);
     }
 
-    private static T FindFactory<T>(FileInfo finfo)
+    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)
         where T : IFactory
     {
         finfo.NotNull(nameof(finfo));
@@ -197,7 +117,7 @@ public static class ArchiveFactory
         return FindFactory<T>(stream);
     }
 
-    private static T FindFactory<T>(Stream stream)
+    public static T FindFactory<T>(Stream stream)
         where T : IFactory
     {
         stream.NotNull(nameof(stream));
@@ -229,68 +149,14 @@ public static class ArchiveFactory
         );
     }
 
-    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
-    )
+    public static bool IsArchive(string filePath, out ArchiveType? type)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
         using Stream s = File.OpenRead(filePath);
-        return IsArchive(s, out type, bufferSize);
+        return IsArchive(s, out type);
     }
 
-    public static bool IsArchive(
-        Stream stream,
-        out ArchiveType? type,
-        int bufferSize = ReaderOptions.DefaultBufferSize
-    )
+    public static bool IsArchive(Stream stream, out ArchiveType? type)
     {
         type = null;
         stream.NotNull(nameof(stream));
@@ -345,6 +211,4 @@ public static class ArchiveFactory
             }
         }
     }
-
-    public static IArchiveFactory AutoFactory { get; } = new AutoArchiveFactory();
 }

src/SharpCompress/Archives/ArchiveVolumeFactory.cs

@@ -13,6 +13,7 @@ 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!,
@@ -22,9 +23,13 @@ internal abstract class ArchiveVolumeFactory
                     )
                 )
             );
+        }
 
         if (item != null && item.Exists)
+        {
             return item;
+        }
+
         return null;
     }
 }

src/SharpCompress/Archives/AutoArchiveFactory.cs

@@ -1,52 +0,0 @@
-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

@@ -0,0 +1,86 @@
+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

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

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -36,19 +36,6 @@ 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,
@@ -92,28 +79,6 @@ 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;
@@ -123,28 +88,10 @@ 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/GZip/GZipWritableArchiveEntry.cs

@@ -58,7 +58,7 @@ internal sealed class GZipWritableArchiveEntry : GZipArchiveEntry, IWritableArch
     {
         //ensure new stream is at the start, this could be reset
         stream.Seek(0, SeekOrigin.Begin);
-        return SharpCompressStream.Create(stream, leaveOpen: true);
+        return SharpCompressStream.CreateNonDisposing(stream);
     }
 
     internal override void Close()

src/SharpCompress/Archives/IArchive.cs

@@ -44,12 +44,4 @@ 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

@@ -9,8 +9,6 @@ namespace SharpCompress.Archives;
 
 public static class IArchiveEntryExtensions
 {
-    private const int BufferSize = 81920;
-
     /// <param name="archiveEntry">The archive entry to extract.</param>
     extension(IArchiveEntry archiveEntry)
     {
@@ -28,7 +26,7 @@ public static class IArchiveEntryExtensions
 
             using var entryStream = archiveEntry.OpenEntryStream();
             var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
-            sourceStream.CopyTo(streamToWriteTo, BufferSize);
+            sourceStream.CopyTo(streamToWriteTo, Constants.BufferSize);
         }
 
         /// <summary>
@@ -48,10 +46,16 @@ public static class IArchiveEntryExtensions
                 throw new ExtractionException("Entry is a file directory and cannot be extracted.");
             }
 
+#if LEGACY_DOTNET
             using var entryStream = await archiveEntry.OpenEntryStreamAsync(cancellationToken);
+#else
+            await using var entryStream = await archiveEntry.OpenEntryStreamAsync(
+                cancellationToken
+            );
+#endif
             var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
             await sourceStream
-                .CopyToAsync(streamToWriteTo, BufferSize, cancellationToken)
+                .CopyToAsync(streamToWriteTo, Constants.BufferSize, cancellationToken)
                 .ConfigureAwait(false);
         }
     }

src/SharpCompress/Archives/IArchiveFactory.cs

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

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

src/SharpCompress/Archives/IWritableArchive.cs

@@ -13,12 +13,10 @@ public interface IWritableArchiveCommon
     /// </summary>
     /// <returns>IDisposeable to resume entry rebuilding</returns>
     IDisposable PauseEntryRebuilding();
+}
 
-    /// <summary>
-    /// Removes the specified entry from the archive.
-    /// </summary>
-    void RemoveEntry(IArchiveEntry entry);
-
+public interface IWritableArchive : IArchive, IWritableArchiveCommon
+{
     IArchiveEntry AddEntry(
         string key,
         Stream source,
@@ -28,14 +26,16 @@ public interface 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
@@ -48,4 +48,30 @@ 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

@@ -1,59 +0,0 @@
-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

@@ -1,3 +1,4 @@
+using System;
 using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Writers;
@@ -8,6 +9,55 @@ 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

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

@@ -36,4 +36,7 @@ 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

@@ -0,0 +1,53 @@
+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

@@ -3,6 +3,7 @@ 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;
@@ -163,4 +164,24 @@ 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

@@ -24,7 +24,10 @@ public interface IRarArchive : IArchive, IRarArchiveCommon { }
 
 public interface IRarAsyncArchive : IAsyncArchive, IRarArchiveCommon { }
 
-public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, IRarArchive
+public partial class RarArchive
+    : AbstractArchive<RarArchiveEntry, RarVolume>,
+        IRarArchive,
+        IRarAsyncArchive
 {
     private bool _disposed;
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
@@ -48,23 +51,14 @@ public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, I
         }
     }
 
-    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();
@@ -86,13 +80,7 @@ public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, I
         return new StreamRarArchiveVolume(sourceStream, ReaderOptions, i++).AsEnumerable();
     }
 
-    protected override IReader CreateReaderForSolidExtraction() =>
-        CreateReaderForSolidExtractionInternal();
-
-    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
-        new(CreateReaderForSolidExtractionInternal());
-
-    private RarReader CreateReaderForSolidExtractionInternal()
+    protected override IReader CreateReaderForSolidExtraction()
     {
         if (this.IsMultipartVolume())
         {
@@ -114,5 +102,6 @@ public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, I
     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

@@ -0,0 +1,43 @@
+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 class RarArchiveEntry : RarEntry, IArchiveEntry
+public partial class RarArchiveEntry : RarEntry, IArchiveEntry
 {
     private readonly ICollection<RarFilePart> parts;
     private readonly RarArchive archive;
@@ -92,32 +92,6 @@ public 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

@@ -17,6 +17,19 @@ 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
     )
@@ -38,6 +51,27 @@ 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,
@@ -49,4 +83,16 @@ 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

@@ -13,6 +13,7 @@ internal static class RarArchiveVolumeFactory
         //new style rar - ..part1 | /part01 | part001 ....
         var m = Regex.Match(part1.Name, @"^(.*\.part)([0-9]+)(\.rar)$", RegexOptions.IgnoreCase);
         if (m.Success)
+        {
             item = new FileInfo(
                 Path.Combine(
                     part1.DirectoryName!,
@@ -23,11 +24,13 @@ internal static class RarArchiveVolumeFactory
                     )
                 )
             );
+        }
         else
         {
             //old style - ...rar, .r00, .r01 ...
             m = Regex.Match(part1.Name, @"^(.*\.)([r-z{])(ar|[0-9]+)$", RegexOptions.IgnoreCase);
             if (m.Success)
+            {
                 item = new FileInfo(
                     Path.Combine(
                         part1.DirectoryName!,
@@ -40,12 +43,17 @@ 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

@@ -1,7 +1,6 @@
 using System.IO;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
-using SharpCompress.IO;
 
 namespace SharpCompress.Archives.Rar;
 
@@ -25,76 +24,6 @@ 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

@@ -14,6 +14,9 @@ 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

@@ -0,0 +1,73 @@
+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

@@ -1,12 +1,10 @@
 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;
 
@@ -157,13 +155,56 @@ public partial class SevenZipArchive
         }
     }
 
-    private static ReadOnlySpan<byte> Signature =>
-        new byte[] { (byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C };
+    public static async ValueTask<bool> IsSevenZipFileAsync(
+        Stream stream,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        try
+        {
+            return await SignatureMatchAsync(stream, cancellationToken);
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    private static ReadOnlySpan<byte> Signature => [(byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C];
 
     private static bool SignatureMatch(Stream stream)
     {
-        var reader = new BinaryReader(stream);
-        ReadOnlySpan<byte> signatureBytes = reader.ReadBytes(6);
-        return signatureBytes.SequenceEqual(Signature);
+        var buffer = ArrayPool<byte>.Shared.Rent(6);
+        try
+        {
+            stream.ReadExact(buffer, 0, 6);
+            return buffer.AsSpan().Slice(0, 6).SequenceEqual(Signature);
+        }
+        finally
+        {
+            ArrayPool<byte>.Shared.Return(buffer);
+        }
+    }
+
+    private static async ValueTask<bool> SignatureMatchAsync(
+        Stream stream,
+        CancellationToken cancellationToken
+    )
+    {
+        var buffer = ArrayPool<byte>.Shared.Rent(6);
+        try
+        {
+            if (!await stream.ReadFullyAsync(buffer, 0, 6, cancellationToken).ConfigureAwait(false))
+            {
+                return false;
+            }
+
+            return buffer.AsSpan().Slice(0, 6).SequenceEqual(Signature);
+        }
+        finally
+        {
+            ArrayPool<byte>.Shared.Return(buffer);
+        }
     }
 }

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -16,48 +16,65 @@ 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) { }
 
-    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();
+        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<SevenZipArchiveEntry> LoadEntries(
         IEnumerable<SevenZipVolume> volumes
     )
     {
-        var stream = volumes.Single().Stream;
-        LoadFactory(stream);
-        if (_database is null)
+        foreach (var volume in volumes)
         {
-            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)
+            LoadFactory(volume.Stream);
+            if (_database is null)
             {
-                entry.IsSolid = isSolid;
-                isSolid = true;
+                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;
             }
         }
-
-        return entries;
     }
 
     private void LoadFactory(Stream stream)
@@ -74,9 +91,6 @@ 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)
@@ -88,13 +102,34 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
     public override long TotalSize =>
         _database?._packSizes.Aggregate(0L, (total, packSize) => total + packSize) ?? 0;
 
-    private sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
+    internal 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) => this._archive = archive;
+            : base(readerOptions, ArchiveType.SevenZip, false) => this._archive = archive;
 
         public override SevenZipVolume Volume => _archive.Volumes.Single();
 
@@ -107,6 +142,10 @@ 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;
@@ -121,10 +160,53 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
             {
                 return CreateEntryStream(Stream.Null);
             }
-            return CreateEntryStream(new SyncOnlyStream(entry.FilePart.GetCompressedStream()));
+
+            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();
         }
     }
 
+    /// <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;
@@ -154,6 +236,7 @@ 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

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

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

@@ -0,0 +1,161 @@
+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

@@ -2,15 +2,13 @@ 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;
 
@@ -23,7 +21,7 @@ public partial class TarArchive
     public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
+        return OpenArchive(new FileInfo(filePath), readerOptions);
     }
 
     public static IWritableArchive OpenArchive(
@@ -36,7 +34,7 @@ public partial class TarArchive
             new SourceStream(
                 fileInfo,
                 i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions()
+                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
             )
         );
     }
@@ -52,7 +50,7 @@ public partial class TarArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions()
+                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
             )
         );
     }
@@ -154,15 +152,48 @@ public partial class TarArchive
         try
         {
             var tarHeader = new TarHeader(new ArchiveEncoding());
-            var readSucceeded = tarHeader.Read(new BinaryReader(stream));
+            var reader = new BinaryReader(stream, Encoding.UTF8, false);
+            var readSucceeded = tarHeader.Read(reader);
             var isEmptyArchive =
                 tarHeader.Name?.Length == 0
                 && tarHeader.Size == 0
                 && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
             return readSucceeded || isEmptyArchive;
         }
-        catch { }
-        return false;
+        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());
+#if NET8_0_OR_GREATER
+            await using var reader = new AsyncBinaryReader(stream, leaveOpen: true);
+#else
+            using var reader = new AsyncBinaryReader(stream, leaveOpen: true);
+#endif
+            var readSucceeded = await tarHeader.ReadAsync(reader);
+            var isEmptyArchive =
+                tarHeader.Name?.Length == 0
+                && tarHeader.Size == 0
+                && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
+            return readSucceeded || isEmptyArchive;
+        }
+        catch (Exception)
+        {
+            // Catch all exceptions during tar header reading to determine if this is a valid tar file
+            // Invalid tar files or corrupted streams will throw various exceptions
+            return false;
+        }
     }
 
     public static IWritableArchive CreateArchive() => new TarArchive();

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -32,6 +32,10 @@ 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(
@@ -62,7 +66,7 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
                         using (var entryStream = entry.OpenEntryStream())
                         {
                             using var memoryStream = new MemoryStream();
-                            entryStream.CopyTo(memoryStream);
+                            entryStream.CopyTo(memoryStream, Constants.BufferSize);
                             memoryStream.Position = 0;
                             var bytes = memoryStream.ToArray();
 
@@ -139,54 +143,10 @@ 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/Tar/TarArchiveEntry.cs

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

src/SharpCompress/Archives/Tar/TarWritableArchiveEntry.cs

@@ -79,7 +79,7 @@ internal sealed class TarWritableArchiveEntry : TarArchiveEntry, IWritableArchiv
         }
         //ensure new stream is at the start, this could be reset
         stream.Seek(0, SeekOrigin.Begin);
-        return SharpCompressStream.Create(stream, leaveOpen: true);
+        return SharpCompressStream.CreateNonDisposing(stream);
     }
 
     internal override void Close()

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

@@ -0,0 +1,132 @@
+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 ?? new ReaderOptions());
+        return OpenArchive(new FileInfo(filePath), readerOptions);
     }
 
     public static IWritableArchive OpenArchive(
@@ -34,7 +34,7 @@ public partial class ZipArchive
             new SourceStream(
                 fileInfo,
                 i => ZipArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions()
+                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
             )
         );
     }
@@ -50,7 +50,7 @@ public partial class ZipArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions()
+                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
             )
         );
     }
@@ -135,40 +135,24 @@ public partial class ZipArchive
         return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
     }
 
-    public static bool IsZipFile(
-        string filePath,
-        string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize
-    ) => IsZipFile(new FileInfo(filePath), password, bufferSize);
+    public static bool IsZipFile(string filePath, string? password = null) =>
+        IsZipFile(new FileInfo(filePath), password);
 
-    public static bool IsZipFile(
-        FileInfo fileInfo,
-        string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize
-    )
+    public static bool IsZipFile(FileInfo fileInfo, string? password = null)
     {
         if (!fileInfo.Exists)
         {
             return false;
         }
         using Stream stream = fileInfo.OpenRead();
-        return IsZipFile(stream, password, bufferSize);
+        return IsZipFile(stream, password);
     }
 
-    public static bool IsZipFile(
-        Stream stream,
-        string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize
-    )
+    public static bool IsZipFile(Stream stream, string? password = null)
     {
         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);
@@ -188,20 +172,11 @@ public partial class ZipArchive
         }
     }
 
-    public static bool IsZipMulti(
-        Stream stream,
-        string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize
-    )
+    public static bool IsZipMulti(Stream stream, string? password = null)
     {
         var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
         try
         {
-            if (stream is not SharpCompressStream)
-            {
-                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
-            }
-
             var header = headerFactory
                 .ReadStreamHeader(stream)
                 .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
@@ -210,7 +185,7 @@ public partial class ZipArchive
                 if (stream.CanSeek)
                 {
                     var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    var x = z.ReadSeekableHeader(stream, useSync: true).FirstOrDefault();
+                    var x = z.ReadSeekableHeader(stream).FirstOrDefault();
                     return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
                 }
                 else
@@ -233,7 +208,6 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipFileAsync(
         Stream stream,
         string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -241,11 +215,6 @@ public partial class ZipArchive
         var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
         try
         {
-            if (stream is not SharpCompressStream)
-            {
-                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
-            }
-
             var header = await headerFactory
                 .ReadStreamHeaderAsync(stream)
                 .Where(x => x.ZipHeaderType != ZipHeaderType.Split)
@@ -273,7 +242,6 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipMultiAsync(
         Stream stream,
         string? password = null,
-        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -281,11 +249,6 @@ public partial class ZipArchive
         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);

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -35,15 +35,18 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
     protected override IEnumerable<ZipVolume> LoadVolumes(SourceStream stream)
     {
         stream.LoadAllParts();
-        stream.Position = 0;
+        //stream.Position = 0;
 
         var streams = stream.Streams.ToList();
         var idx = 0;
         if (streams.Count() > 1)
         {
-            streams[1].Position += 4;
-            var isZip = IsZipFile(streams[1], ReaderOptions.Password, ReaderOptions.BufferSize);
-            streams[1].Position -= 4;
+            //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;
             if (isZip)
             {
                 stream.IsVolumes = true;
@@ -62,9 +65,7 @@ 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, useSync: true)
-        )
+        foreach (var h in headerFactory.NotNull().ReadSeekableHeader(vols.Last().Stream))
         {
             if (h != null)
             {
@@ -108,59 +109,6 @@ 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(
@@ -192,41 +140,6 @@ 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,
@@ -243,7 +156,7 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
-        ((IStreamStack)stream).StackSeek(0);
+        //stream.Position = 0;
         return ZipReader.OpenReader(stream, ReaderOptions, Entries);
     }
 

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

@@ -0,0 +1,22 @@
+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

@@ -6,25 +6,13 @@ using SharpCompress.Common.Zip;
 
 namespace SharpCompress.Archives.Zip;
 
-public class ZipArchiveEntry : ZipEntry, IArchiveEntry
+public partial 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

@@ -14,6 +14,7 @@ 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!,
@@ -24,11 +25,16 @@ 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/Archives/Zip/ZipWritableArchiveEntry.cs

@@ -80,7 +80,7 @@ internal class ZipWritableArchiveEntry : ZipArchiveEntry, IWritableArchiveEntry
         }
         //ensure new stream is at the start, this could be reset
         stream.Seek(0, SeekOrigin.Begin);
-        return SharpCompressStream.Create(stream, leaveOpen: true);
+        return SharpCompressStream.CreateNonDisposing(stream);
     }
 
     internal override void Close()

src/SharpCompress/Common/Ace/AceCrc.cs

@@ -4,58 +4,61 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Ace
+namespace SharpCompress.Common.Ace;
+
+public class AceCrc
 {
-    public class AceCrc
+    // CRC-32 lookup table (standard polynomial 0xEDB88320, reflected)
+    private static readonly uint[] Crc32Table = GenerateTable();
+
+    private static uint[] GenerateTable()
     {
-        // CRC-32 lookup table (standard polynomial 0xEDB88320, reflected)
-        private static readonly uint[] Crc32Table = GenerateTable();
+        var table = new uint[256];
 
-        private static uint[] GenerateTable()
+        for (int i = 0; i < 256; i++)
         {
-            var table = new uint[256];
+            uint crc = (uint)i;
 
-            for (int i = 0; i < 256; i++)
+            for (int j = 0; j < 8; j++)
             {
-                uint crc = (uint)i;
-
-                for (int j = 0; j < 8; j++)
+                if ((crc & 1) != 0)
                 {
-                    if ((crc & 1) != 0)
-                        crc = (crc >> 1) ^ 0xEDB88320u;
-                    else
-                        crc >>= 1;
+                    crc = (crc >> 1) ^ 0xEDB88320u;
+                }
+                else
+                {
+                    crc >>= 1;
                 }
-
-                table[i] = crc;
             }
 
-            return table;
+            table[i] = crc;
         }
 
-        /// <summary>
-        /// Calculate ACE CRC-32 checksum.
-        /// ACE CRC-32 uses standard CRC-32 polynomial (0xEDB88320, reflected)
-        /// with init=0xFFFFFFFF but NO final XOR.
-        /// </summary>
-        public static uint AceCrc32(ReadOnlySpan<byte> data)
+        return table;
+    }
+
+    /// <summary>
+    /// Calculate ACE CRC-32 checksum.
+    /// ACE CRC-32 uses standard CRC-32 polynomial (0xEDB88320, reflected)
+    /// with init=0xFFFFFFFF but NO final XOR.
+    /// </summary>
+    public static uint AceCrc32(ReadOnlySpan<byte> data)
+    {
+        uint crc = 0xFFFFFFFFu;
+
+        foreach (byte b in data)
         {
-            uint crc = 0xFFFFFFFFu;
-
-            foreach (byte b in data)
-            {
-                crc = (crc >> 8) ^ Crc32Table[(crc ^ b) & 0xFF];
-            }
-
-            return crc; // No final XOR for ACE
+            crc = (crc >> 8) ^ Crc32Table[(crc ^ b) & 0xFF];
         }
 
-        /// <summary>
-        /// ACE CRC-16 is the lower 16 bits of the ACE CRC-32.
-        /// </summary>
-        public static ushort AceCrc16(ReadOnlySpan<byte> data)
-        {
-            return (ushort)(AceCrc32(data) & 0xFFFF);
-        }
+        return crc; // No final XOR for ACE
+    }
+
+    /// <summary>
+    /// ACE CRC-16 is the lower 16 bits of the ACE CRC-32.
+    /// </summary>
+    public static ushort AceCrc16(ReadOnlySpan<byte> data)
+    {
+        return (ushort)(AceCrc32(data) & 0xFFFF);
     }
 }

src/SharpCompress/Common/Ace/AceEntry.cs

@@ -6,63 +6,62 @@ using System.Text;
 using System.Threading.Tasks;
 using SharpCompress.Common.Ace.Headers;
 
-namespace SharpCompress.Common.Ace
+namespace SharpCompress.Common.Ace;
+
+public class AceEntry : Entry
 {
-    public class AceEntry : Entry
+    private readonly AceFilePart _filePart;
+
+    internal AceEntry(AceFilePart filePart)
     {
-        private readonly AceFilePart _filePart;
-
-        internal AceEntry(AceFilePart filePart)
-        {
-            _filePart = filePart;
-        }
-
-        public override long Crc
-        {
-            get
-            {
-                if (_filePart == null)
-                {
-                    return 0;
-                }
-                return _filePart.Header.Crc32;
-            }
-        }
-
-        public override string? Key => _filePart?.Header.Filename;
-
-        public override string? LinkTarget => null;
-
-        public override long CompressedSize => _filePart?.Header.PackedSize ?? 0;
-
-        public override CompressionType CompressionType
-        {
-            get
-            {
-                if (_filePart.Header.CompressionType == Headers.CompressionType.Stored)
-                {
-                    return CompressionType.None;
-                }
-                return CompressionType.AceLZ77;
-            }
-        }
-
-        public override long Size => _filePart?.Header.OriginalSize ?? 0;
-
-        public override DateTime? LastModifiedTime => _filePart.Header.DateTime;
-
-        public override DateTime? CreatedTime => null;
-
-        public override DateTime? LastAccessedTime => null;
-
-        public override DateTime? ArchivedTime => null;
-
-        public override bool IsEncrypted => _filePart.Header.IsFileEncrypted;
-
-        public override bool IsDirectory => _filePart.Header.IsDirectory;
-
-        public override bool IsSplitAfter => false;
-
-        internal override IEnumerable<FilePart> Parts => _filePart.Empty();
+        _filePart = filePart;
     }
+
+    public override long Crc
+    {
+        get
+        {
+            if (_filePart == null)
+            {
+                return 0;
+            }
+            return _filePart.Header.Crc32;
+        }
+    }
+
+    public override string? Key => _filePart?.Header.Filename;
+
+    public override string? LinkTarget => null;
+
+    public override long CompressedSize => _filePart?.Header.PackedSize ?? 0;
+
+    public override CompressionType CompressionType
+    {
+        get
+        {
+            if (_filePart.Header.CompressionType == Headers.CompressionType.Stored)
+            {
+                return CompressionType.None;
+            }
+            return CompressionType.AceLZ77;
+        }
+    }
+
+    public override long Size => _filePart?.Header.OriginalSize ?? 0;
+
+    public override DateTime? LastModifiedTime => _filePart.Header.DateTime;
+
+    public override DateTime? CreatedTime => null;
+
+    public override DateTime? LastAccessedTime => null;
+
+    public override DateTime? ArchivedTime => null;
+
+    public override bool IsEncrypted => _filePart.Header.IsFileEncrypted;
+
+    public override bool IsDirectory => _filePart.Header.IsDirectory;
+
+    public override bool IsSplitAfter => false;
+
+    internal override IEnumerable<FilePart> Parts => _filePart.Empty();
 }

src/SharpCompress/Common/Ace/AceFilePart.cs

@@ -7,46 +7,45 @@ using System.Threading.Tasks;
 using SharpCompress.Common.Ace.Headers;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Ace
+namespace SharpCompress.Common.Ace;
+
+public class AceFilePart : FilePart
 {
-    public class AceFilePart : FilePart
+    private readonly Stream _stream;
+    internal AceFileHeader Header { get; set; }
+
+    internal AceFilePart(AceFileHeader localAceHeader, Stream seekableStream)
+        : base(localAceHeader.ArchiveEncoding)
     {
-        private readonly Stream _stream;
-        internal AceFileHeader Header { get; set; }
-
-        internal AceFilePart(AceFileHeader localAceHeader, Stream seekableStream)
-            : base(localAceHeader.ArchiveEncoding)
-        {
-            _stream = seekableStream;
-            Header = localAceHeader;
-        }
-
-        internal override string? FilePartName => Header.Filename;
-
-        internal override Stream GetCompressedStream()
-        {
-            if (_stream != null)
-            {
-                Stream compressedStream;
-                switch (Header.CompressionType)
-                {
-                    case Headers.CompressionType.Stored:
-                        compressedStream = new ReadOnlySubStream(
-                            _stream,
-                            Header.DataStartPosition,
-                            Header.PackedSize
-                        );
-                        break;
-                    default:
-                        throw new NotSupportedException(
-                            "CompressionMethod: " + Header.CompressionQuality
-                        );
-                }
-                return compressedStream;
-            }
-            return _stream.NotNull();
-        }
-
-        internal override Stream? GetRawStream() => _stream;
+        _stream = seekableStream;
+        Header = localAceHeader;
     }
+
+    internal override string? FilePartName => Header.Filename;
+
+    internal override Stream GetCompressedStream()
+    {
+        if (_stream != null)
+        {
+            Stream compressedStream;
+            switch (Header.CompressionType)
+            {
+                case Headers.CompressionType.Stored:
+                    compressedStream = new ReadOnlySubStream(
+                        _stream,
+                        Header.DataStartPosition,
+                        Header.PackedSize
+                    );
+                    break;
+                default:
+                    throw new NotSupportedException(
+                        "CompressionMethod: " + Header.CompressionQuality
+                    );
+            }
+            return compressedStream;
+        }
+        return _stream.NotNull();
+    }
+
+    internal override Stream? GetRawStream() => _stream;
 }

src/SharpCompress/Common/Ace/AceVolume.cs

@@ -7,29 +7,28 @@ using System.Threading.Tasks;
 using SharpCompress.Common.Arj;
 using SharpCompress.Readers;
 
-namespace SharpCompress.Common.Ace
+namespace SharpCompress.Common.Ace;
+
+public class AceVolume : Volume
 {
-    public class AceVolume : Volume
+    public AceVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
+        : base(stream, readerOptions, index) { }
+
+    public override bool IsFirstVolume
     {
-        public AceVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
-            : base(stream, readerOptions, index) { }
+        get { return true; }
+    }
 
-        public override bool IsFirstVolume
-        {
-            get { return true; }
-        }
+    /// <summary>
+    /// ArjArchive is part of a multi-part archive.
+    /// </summary>
+    public override bool IsMultiVolume
+    {
+        get { return false; }
+    }
 
-        /// <summary>
-        /// ArjArchive is part of a multi-part archive.
-        /// </summary>
-        public override bool IsMultiVolume
-        {
-            get { return false; }
-        }
-
-        internal IEnumerable<AceFilePart> GetVolumeFileParts()
-        {
-            return new List<AceFilePart>();
-        }
+    internal IEnumerable<AceFilePart> GetVolumeFileParts()
+    {
+        return new List<AceFilePart>();
     }
 }

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

@@ -0,0 +1,111 @@
+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

@@ -2,170 +2,173 @@ 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;
 
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// ACE file entry header
+/// </summary>
+public sealed partial class AceFileHeader : AceHeader
 {
+    public long DataStartPosition { get; private set; }
+    public long PackedSize { get; set; }
+    public long OriginalSize { get; set; }
+    public DateTime DateTime { get; set; }
+    public int Attributes { get; set; }
+    public uint Crc32 { get; set; }
+    public CompressionType CompressionType { get; set; }
+    public CompressionQuality CompressionQuality { get; set; }
+    public ushort Parameters { get; set; }
+    public string Filename { get; set; } = string.Empty;
+    public List<byte> Comment { get; set; } = new();
+
     /// <summary>
-    /// ACE file entry header
+    /// File data offset in the archive
     /// </summary>
-    public sealed class AceFileHeader : AceHeader
+    public ulong DataOffset { get; set; }
+
+    public bool IsDirectory => (Attributes & 0x10) != 0;
+
+    public bool IsContinuedFromPrev =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.CONTINUED_PREV) != 0;
+
+    public bool IsContinuedToNext =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.CONTINUED_NEXT) != 0;
+
+    public int DictionarySize
     {
-        public long DataStartPosition { get; private set; }
-        public long PackedSize { get; set; }
-        public long OriginalSize { get; set; }
-        public DateTime DateTime { get; set; }
-        public int Attributes { get; set; }
-        public uint Crc32 { get; set; }
-        public CompressionType CompressionType { get; set; }
-        public CompressionQuality CompressionQuality { get; set; }
-        public ushort Parameters { get; set; }
-        public string Filename { get; set; } = string.Empty;
-        public List<byte> Comment { get; set; } = new();
-
-        /// <summary>
-        /// File data offset in the archive
-        /// </summary>
-        public ulong DataOffset { get; set; }
-
-        public bool IsDirectory => (Attributes & 0x10) != 0;
-
-        public bool IsContinuedFromPrev =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.CONTINUED_PREV) != 0;
-
-        public bool IsContinuedToNext =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.CONTINUED_NEXT) != 0;
-
-        public int DictionarySize
+        get
         {
-            get
-            {
-                int bits = Parameters & 0x0F;
-                return bits < 10 ? 1024 : 1 << bits;
-            }
+            int bits = Parameters & 0x0F;
+            return bits < 10 ? 1024 : 1 << bits;
         }
-
-        public AceFileHeader(IArchiveEncoding archiveEncoding)
-            : base(archiveEncoding, AceHeaderType.FILE) { }
-
-        /// <summary>
-        /// 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 AceHeader? Read(Stream stream)
-        {
-            var headerData = ReadHeader(stream);
-            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;
-        }
-
-        public CompressionType GetCompressionType(byte value) =>
-            value switch
-            {
-                0 => CompressionType.Stored,
-                1 => CompressionType.Lz77,
-                2 => CompressionType.Blocked,
-                _ => CompressionType.Unknown,
-            };
-
-        public CompressionQuality GetCompressionQuality(byte value) =>
-            value switch
-            {
-                0 => CompressionQuality.None,
-                1 => CompressionQuality.Fastest,
-                2 => CompressionQuality.Fast,
-                3 => CompressionQuality.Normal,
-                4 => CompressionQuality.Good,
-                5 => CompressionQuality.Best,
-                _ => CompressionQuality.Unknown,
-            };
     }
+
+    public AceFileHeader(IArchiveEncoding archiveEncoding)
+        : base(archiveEncoding, AceHeaderType.FILE) { }
+
+    /// <summary>
+    /// 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 AceHeader? Read(Stream stream)
+    {
+        var headerData = ReadHeader(stream);
+        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;
+    }
+
+    // ReadAsync moved to AceFileHeader.Async.cs
+
+    public CompressionType GetCompressionType(byte value) =>
+        value switch
+        {
+            0 => CompressionType.Stored,
+            1 => CompressionType.Lz77,
+            2 => CompressionType.Blocked,
+            _ => CompressionType.Unknown,
+        };
+
+    public CompressionQuality GetCompressionQuality(byte value) =>
+        value switch
+        {
+            0 => CompressionQuality.None,
+            1 => CompressionQuality.Fastest,
+            2 => CompressionQuality.Fast,
+            3 => CompressionQuality.Normal,
+            4 => CompressionQuality.Good,
+            5 => CompressionQuality.Best,
+            _ => CompressionQuality.Unknown,
+        };
 }

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

@@ -0,0 +1,69 @@
+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.ReadFullyAsync(headerBytes, 0, 4, cancellationToken))
+        {
+            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.ReadFullyAsync(body, 0, HeaderSize, cancellationToken))
+        {
+            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.ReadFullyAsync(bytes, 0, 14, cancellationToken))
+        {
+            return false;
+        }
+
+        return CheckMagicBytes(bytes, 7);
+    }
+}

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

@@ -1,153 +1,156 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Arj.Headers;
 using SharpCompress.Crypto;
 
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// Header type constants
+/// </summary>
+public enum AceHeaderType
 {
-    /// <summary>
-    /// Header type constants
-    /// </summary>
-    public enum AceHeaderType
+    MAIN = 0,
+    FILE = 1,
+    RECOVERY32 = 2,
+    RECOVERY64A = 3,
+    RECOVERY64B = 4,
+}
+
+public abstract partial class AceHeader
+{
+    // ACE signature: bytes at offset 7 should be "**ACE**"
+    private static readonly byte[] AceSignature =
+    [
+        (byte)'*',
+        (byte)'*',
+        (byte)'A',
+        (byte)'C',
+        (byte)'E',
+        (byte)'*',
+        (byte)'*',
+    ];
+
+    public AceHeader(IArchiveEncoding archiveEncoding, AceHeaderType type)
     {
-        MAIN = 0,
-        FILE = 1,
-        RECOVERY32 = 2,
-        RECOVERY64A = 3,
-        RECOVERY64B = 4,
+        AceHeaderType = type;
+        ArchiveEncoding = archiveEncoding;
     }
 
-    public abstract class AceHeader
+    public IArchiveEncoding ArchiveEncoding { get; }
+    public AceHeaderType AceHeaderType { get; }
+
+    public ushort HeaderFlags { get; set; }
+    public ushort HeaderCrc { get; set; }
+    public ushort HeaderSize { get; set; }
+    public byte HeaderType { get; set; }
+
+    public bool IsFileEncrypted =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.FILE_ENCRYPTED) != 0;
+    public bool Is64Bit =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.MEMORY_64BIT) != 0;
+
+    public bool IsSolid =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.SOLID_MAIN) != 0;
+
+    public bool IsMultiVolume =>
+        (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.MULTIVOLUME) != 0;
+
+    public abstract AceHeader? Read(Stream reader);
+
+    // Async methods moved to AceHeader.Async.cs
+
+    public byte[] ReadHeader(Stream stream)
     {
-        // ACE signature: bytes at offset 7 should be "**ACE**"
-        private static readonly byte[] AceSignature =
-        [
-            (byte)'*',
-            (byte)'*',
-            (byte)'A',
-            (byte)'C',
-            (byte)'E',
-            (byte)'*',
-            (byte)'*',
-        ];
-
-        public AceHeader(IArchiveEncoding archiveEncoding, AceHeaderType type)
+        // Read header CRC (2 bytes) and header size (2 bytes)
+        var headerBytes = new byte[4];
+        if (!stream.ReadFully(headerBytes))
         {
-            AceHeaderType = type;
-            ArchiveEncoding = archiveEncoding;
+            return Array.Empty<byte>();
         }
 
-        public IArchiveEncoding ArchiveEncoding { get; }
-        public AceHeaderType AceHeaderType { get; }
-
-        public ushort HeaderFlags { get; set; }
-        public ushort HeaderCrc { get; set; }
-        public ushort HeaderSize { get; set; }
-        public byte HeaderType { get; set; }
-
-        public bool IsFileEncrypted =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.FILE_ENCRYPTED) != 0;
-        public bool Is64Bit =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.MEMORY_64BIT) != 0;
-
-        public bool IsSolid =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.SOLID_MAIN) != 0;
-
-        public bool IsMultiVolume =>
-            (HeaderFlags & SharpCompress.Common.Ace.Headers.HeaderFlags.MULTIVOLUME) != 0;
-
-        public abstract AceHeader? Read(Stream reader);
-
-        public byte[] ReadHeader(Stream stream)
+        HeaderCrc = BitConverter.ToUInt16(headerBytes, 0); // CRC for validation
+        HeaderSize = BitConverter.ToUInt16(headerBytes, 2);
+        if (HeaderSize == 0)
         {
-            // Read header CRC (2 bytes) and header size (2 bytes)
-            var headerBytes = new byte[4];
-            if (stream.Read(headerBytes, 0, 4) != 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 (stream.Read(body, 0, HeaderSize) != HeaderSize)
-            {
-                return Array.Empty<byte>();
-            }
-
-            // Verify crc
-            var checksum = AceCrc.AceCrc16(body);
-            if (checksum != HeaderCrc)
-            {
-                throw new InvalidDataException("Header checksum is invalid");
-            }
-            return body;
+            return Array.Empty<byte>();
         }
 
-        public static bool IsArchive(Stream stream)
+        // Read the header data
+        var body = new byte[HeaderSize];
+        if (!stream.ReadFully(body))
         {
-            // ACE files have a specific signature
-            // First two bytes are typically 0x60 0xEA (signature bytes)
-            // At offset 7, there should be "**ACE**" (7 bytes)
-            var bytes = new byte[14];
-            if (stream.Read(bytes, 0, 14) != 14)
+            return Array.Empty<byte>();
+        }
+
+        // Verify crc
+        var checksum = AceCrc.AceCrc16(body);
+        if (checksum != HeaderCrc)
+        {
+            throw new InvalidDataException("Header checksum is invalid");
+        }
+        return body;
+    }
+
+    public static bool IsArchive(Stream stream)
+    {
+        // ACE files have a specific signature
+        // First two bytes are typically 0x60 0xEA (signature bytes)
+        // At offset 7, there should be "**ACE**" (7 bytes)
+        var bytes = new byte[14];
+        if (stream.Read(bytes, 0, 14) != 14)
+        {
+            return false;
+        }
+
+        // Check for "**ACE**" at offset 7
+        return CheckMagicBytes(bytes, 7);
+    }
+
+    protected static bool CheckMagicBytes(byte[] headerBytes, int offset)
+    {
+        // Check for "**ACE**" at specified offset
+        for (int i = 0; i < AceSignature.Length; i++)
+        {
+            if (headerBytes[offset + i] != AceSignature[i])
             {
                 return false;
             }
-
-            // Check for "**ACE**" at offset 7
-            return CheckMagicBytes(bytes, 7);
         }
+        return true;
+    }
 
-        protected static bool CheckMagicBytes(byte[] headerBytes, int offset)
+    protected DateTime ConvertDosDateTime(uint dosDateTime)
+    {
+        try
         {
-            // Check for "**ACE**" at specified offset
-            for (int i = 0; i < AceSignature.Length; i++)
-            {
-                if (headerBytes[offset + i] != AceSignature[i])
-                {
-                    return false;
-                }
-            }
-            return true;
-        }
+            int second = (int)(dosDateTime & 0x1F) * 2;
+            int minute = (int)((dosDateTime >> 5) & 0x3F);
+            int hour = (int)((dosDateTime >> 11) & 0x1F);
+            int day = (int)((dosDateTime >> 16) & 0x1F);
+            int month = (int)((dosDateTime >> 21) & 0x0F);
+            int year = (int)((dosDateTime >> 25) & 0x7F) + 1980;
 
-        protected DateTime ConvertDosDateTime(uint dosDateTime)
-        {
-            try
-            {
-                int second = (int)(dosDateTime & 0x1F) * 2;
-                int minute = (int)((dosDateTime >> 5) & 0x3F);
-                int hour = (int)((dosDateTime >> 11) & 0x1F);
-                int day = (int)((dosDateTime >> 16) & 0x1F);
-                int month = (int)((dosDateTime >> 21) & 0x0F);
-                int year = (int)((dosDateTime >> 25) & 0x7F) + 1980;
-
-                if (
-                    day < 1
-                    || day > 31
-                    || month < 1
-                    || month > 12
-                    || hour > 23
-                    || minute > 59
-                    || second > 59
-                )
-                {
-                    return DateTime.MinValue;
-                }
-
-                return new DateTime(year, month, day, hour, minute, second);
-            }
-            catch
+            if (
+                day < 1
+                || day > 31
+                || month < 1
+                || month > 12
+                || hour > 23
+                || minute > 59
+                || second > 59
+            )
             {
                 return DateTime.MinValue;
             }
+
+            return new DateTime(year, month, day, hour, minute, second);
+        }
+        catch
+        {
+            return DateTime.MinValue;
         }
     }
 }

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

@@ -0,0 +1,83 @@
+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

@@ -2,96 +2,99 @@ 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;
 
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// ACE main archive header
+/// </summary>
+public sealed partial class AceMainHeader : AceHeader
 {
+    public byte ExtractVersion { get; set; }
+    public byte CreatorVersion { get; set; }
+    public HostOS HostOS { get; set; }
+    public byte VolumeNumber { get; set; }
+    public DateTime DateTime { get; set; }
+    public string Advert { get; set; } = string.Empty;
+    public List<byte> Comment { get; set; } = new();
+    public byte AceVersion { get; private set; }
+
+    public AceMainHeader(IArchiveEncoding archiveEncoding)
+        : base(archiveEncoding, AceHeaderType.MAIN) { }
+
     /// <summary>
-    /// ACE main archive header
+    /// 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 sealed class AceMainHeader : AceHeader
+    public override AceHeader? Read(Stream stream)
     {
-        public byte ExtractVersion { get; set; }
-        public byte CreatorVersion { get; set; }
-        public HostOS HostOS { get; set; }
-        public byte VolumeNumber { get; set; }
-        public DateTime DateTime { get; set; }
-        public string Advert { get; set; } = string.Empty;
-        public List<byte> Comment { get; set; } = new();
-        public byte AceVersion { get; private set; }
-
-        public AceMainHeader(IArchiveEncoding archiveEncoding)
-            : base(archiveEncoding, AceHeaderType.MAIN) { }
-
-        /// <summary>
-        /// 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 AceHeader? Read(Stream stream)
+        var headerData = ReadHeader(stream);
+        if (headerData.Length == 0)
         {
-            var headerData = ReadHeader(stream);
-            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;
+            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;
     }
+
+    // ReadAsync moved to AceMainHeader.Async.cs
 }

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

@@ -1,16 +1,15 @@
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// Compression quality
+/// </summary>
+public enum CompressionQuality
 {
-    /// <summary>
-    /// Compression quality
-    /// </summary>
-    public enum CompressionQuality
-    {
-        None,
-        Fastest,
-        Fast,
-        Normal,
-        Good,
-        Best,
-        Unknown,
-    }
+    None,
+    Fastest,
+    Fast,
+    Normal,
+    Good,
+    Best,
+    Unknown,
 }

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

@@ -1,13 +1,12 @@
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// Compression types
+/// </summary>
+public enum CompressionType
 {
-    /// <summary>
-    /// Compression types
-    /// </summary>
-    public enum CompressionType
-    {
-        Stored,
-        Lz77,
-        Blocked,
-        Unknown,
-    }
+    Stored,
+    Lz77,
+    Blocked,
+    Unknown,
 }

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

@@ -1,33 +1,32 @@
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// Header flags (main + file, overlapping meanings)
+/// </summary>
+public static class HeaderFlags
 {
-    /// <summary>
-    /// Header flags (main + file, overlapping meanings)
-    /// </summary>
-    public static class HeaderFlags
-    {
-        // Shared / low bits
-        public const ushort ADDSIZE = 0x0001; // extra size field present
-        public const ushort COMMENT = 0x0002; // comment present
-        public const ushort MEMORY_64BIT = 0x0004;
-        public const ushort AV_STRING = 0x0008; // AV string present
-        public const ushort SOLID = 0x0010; // solid file
-        public const ushort LOCKED = 0x0020;
-        public const ushort PROTECTED = 0x0040;
+    // Shared / low bits
+    public const ushort ADDSIZE = 0x0001; // extra size field present
+    public const ushort COMMENT = 0x0002; // comment present
+    public const ushort MEMORY_64BIT = 0x0004;
+    public const ushort AV_STRING = 0x0008; // AV string present
+    public const ushort SOLID = 0x0010; // solid file
+    public const ushort LOCKED = 0x0020;
+    public const ushort PROTECTED = 0x0040;
 
-        // Main header specific
-        public const ushort V20FORMAT = 0x0100;
-        public const ushort SFX = 0x0200;
-        public const ushort LIMITSFXJR = 0x0400;
-        public const ushort MULTIVOLUME = 0x0800;
-        public const ushort ADVERT = 0x1000;
-        public const ushort RECOVERY = 0x2000;
-        public const ushort LOCKED_MAIN = 0x4000;
-        public const ushort SOLID_MAIN = 0x8000;
+    // Main header specific
+    public const ushort V20FORMAT = 0x0100;
+    public const ushort SFX = 0x0200;
+    public const ushort LIMITSFXJR = 0x0400;
+    public const ushort MULTIVOLUME = 0x0800;
+    public const ushort ADVERT = 0x1000;
+    public const ushort RECOVERY = 0x2000;
+    public const ushort LOCKED_MAIN = 0x4000;
+    public const ushort SOLID_MAIN = 0x8000;
 
-        // File header specific (same bits, different meaning)
-        public const ushort NTSECURITY = 0x0400;
-        public const ushort CONTINUED_PREV = 0x1000;
-        public const ushort CONTINUED_NEXT = 0x2000;
-        public const ushort FILE_ENCRYPTED = 0x4000; // file encrypted (file header)
-    }
+    // File header specific (same bits, different meaning)
+    public const ushort NTSECURITY = 0x0400;
+    public const ushort CONTINUED_PREV = 0x1000;
+    public const ushort CONTINUED_NEXT = 0x2000;
+    public const ushort FILE_ENCRYPTED = 0x4000; // file encrypted (file header)
 }

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

@@ -1,22 +1,21 @@
-namespace SharpCompress.Common.Ace.Headers
+namespace SharpCompress.Common.Ace.Headers;
+
+/// <summary>
+/// Host OS type
+/// </summary>
+public enum HostOS
 {
-    /// <summary>
-    /// Host OS type
-    /// </summary>
-    public enum HostOS
-    {
-        MsDos = 0,
-        Os2,
-        Windows,
-        Unix,
-        MacOs,
-        WinNt,
-        Primos,
-        AppleGs,
-        Atari,
-        Vax,
-        Amiga,
-        Next,
-        Unknown,
-    }
+    MsDos = 0,
+    Os2,
+    Windows,
+    Unix,
+    MacOs,
+    WinNt,
+    Primos,
+    AppleGs,
+    Atari,
+    Vax,
+    Amiga,
+    Next,
+    Unknown,
 }

src/SharpCompress/Common/Arc/ArcEntry.cs

@@ -7,54 +7,53 @@ using System.Threading.Tasks;
 using SharpCompress.Common.GZip;
 using SharpCompress.Common.Tar;
 
-namespace SharpCompress.Common.Arc
+namespace SharpCompress.Common.Arc;
+
+public class ArcEntry : Entry
 {
-    public class ArcEntry : Entry
+    private readonly ArcFilePart? _filePart;
+
+    internal ArcEntry(ArcFilePart? filePart)
     {
-        private readonly ArcFilePart? _filePart;
-
-        internal ArcEntry(ArcFilePart? filePart)
-        {
-            _filePart = filePart;
-        }
-
-        public override long Crc
-        {
-            get
-            {
-                if (_filePart == null)
-                {
-                    return 0;
-                }
-                return _filePart.Header.Crc16;
-            }
-        }
-
-        public override string? Key => _filePart?.Header.Name;
-
-        public override string? LinkTarget => null;
-
-        public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
-
-        public override CompressionType CompressionType =>
-            _filePart?.Header.CompressionMethod ?? CompressionType.Unknown;
-
-        public override long Size => throw new NotImplementedException();
-
-        public override DateTime? LastModifiedTime => null;
-
-        public override DateTime? CreatedTime => null;
-
-        public override DateTime? LastAccessedTime => null;
-
-        public override DateTime? ArchivedTime => null;
-
-        public override bool IsEncrypted => false;
-
-        public override bool IsDirectory => false;
-
-        public override bool IsSplitAfter => false;
-
-        internal override IEnumerable<FilePart> Parts => _filePart.Empty();
+        _filePart = filePart;
     }
+
+    public override long Crc
+    {
+        get
+        {
+            if (_filePart == null)
+            {
+                return 0;
+            }
+            return _filePart.Header.Crc16;
+        }
+    }
+
+    public override string? Key => _filePart?.Header.Name;
+
+    public override string? LinkTarget => null;
+
+    public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
+
+    public override CompressionType CompressionType =>
+        _filePart?.Header.CompressionMethod ?? CompressionType.Unknown;
+
+    public override long Size => throw new NotImplementedException();
+
+    public override DateTime? LastModifiedTime => null;
+
+    public override DateTime? CreatedTime => null;
+
+    public override DateTime? LastAccessedTime => null;
+
+    public override DateTime? ArchivedTime => null;
+
+    public override bool IsEncrypted => false;
+
+    public override bool IsDirectory => false;
+
+    public override bool IsSplitAfter => false;
+
+    internal override IEnumerable<FilePart> Parts => _filePart.Empty();
 }

src/SharpCompress/Common/Arc/ArcEntryHeader.cs

@@ -2,75 +2,93 @@ using System;
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Arc
+namespace SharpCompress.Common.Arc;
+
+public class ArcEntryHeader
 {
-    public class ArcEntryHeader
+    public IArchiveEncoding ArchiveEncoding { get; }
+    public CompressionType CompressionMethod { get; private set; }
+    public string? Name { get; private set; }
+    public long CompressedSize { get; private set; }
+    public DateTime DateTime { get; private set; }
+    public int Crc16 { get; private set; }
+    public long OriginalSize { get; private set; }
+    public long DataStartPosition { get; private set; }
+
+    public ArcEntryHeader(IArchiveEncoding archiveEncoding)
     {
-        public IArchiveEncoding ArchiveEncoding { get; }
-        public CompressionType CompressionMethod { get; private set; }
-        public string? Name { get; private set; }
-        public long CompressedSize { get; private set; }
-        public DateTime DateTime { get; private set; }
-        public int Crc16 { get; private set; }
-        public long OriginalSize { get; private set; }
-        public long DataStartPosition { get; private set; }
+        this.ArchiveEncoding = archiveEncoding;
+    }
 
-        public ArcEntryHeader(IArchiveEncoding archiveEncoding)
+    public ArcEntryHeader? ReadHeader(Stream stream)
+    {
+        byte[] headerBytes = new byte[29];
+        if (stream.Read(headerBytes, 0, headerBytes.Length) != headerBytes.Length)
         {
-            this.ArchiveEncoding = archiveEncoding;
+            return null;
         }
+        DataStartPosition = stream.Position;
+        return LoadFrom(headerBytes);
+    }
 
-        public ArcEntryHeader? ReadHeader(Stream stream)
+    public async ValueTask<ArcEntryHeader?> ReadHeaderAsync(
+        Stream stream,
+        CancellationToken cancellationToken = default
+    )
+    {
+        byte[] headerBytes = new byte[29];
+        if (
+            await stream.ReadAsync(headerBytes, 0, headerBytes.Length, cancellationToken)
+            != headerBytes.Length
+        )
         {
-            byte[] headerBytes = new byte[29];
-            if (stream.Read(headerBytes, 0, headerBytes.Length) != headerBytes.Length)
-            {
-                return null;
-            }
-            DataStartPosition = stream.Position;
-            return LoadFrom(headerBytes);
+            return null;
         }
+        DataStartPosition = stream.Position;
+        return LoadFrom(headerBytes);
+    }
 
-        public ArcEntryHeader LoadFrom(byte[] headerBytes)
+    public ArcEntryHeader LoadFrom(byte[] headerBytes)
+    {
+        CompressionMethod = GetCompressionType(headerBytes[1]);
+
+        // Read name
+        int nameEnd = Array.IndexOf(headerBytes, (byte)0, 1); // Find null terminator
+        Name = Encoding.UTF8.GetString(headerBytes, 2, nameEnd > 0 ? nameEnd - 2 : 12);
+
+        int offset = 15;
+        CompressedSize = BitConverter.ToUInt32(headerBytes, offset);
+        offset += 4;
+        uint rawDateTime = BitConverter.ToUInt32(headerBytes, offset);
+        DateTime = ConvertToDateTime(rawDateTime);
+        offset += 4;
+        Crc16 = BitConverter.ToUInt16(headerBytes, offset);
+        offset += 2;
+        OriginalSize = BitConverter.ToUInt32(headerBytes, offset);
+        return this;
+    }
+
+    private CompressionType GetCompressionType(byte value)
+    {
+        return value switch
         {
-            CompressionMethod = GetCompressionType(headerBytes[1]);
+            1 or 2 => CompressionType.None,
+            3 => CompressionType.Packed,
+            4 => CompressionType.Squeezed,
+            5 or 6 or 7 or 8 => CompressionType.Crunched,
+            9 => CompressionType.Squashed,
+            10 => CompressionType.Crushed,
+            11 => CompressionType.Distilled,
+            _ => CompressionType.Unknown,
+        };
+    }
 
-            // Read name
-            int nameEnd = Array.IndexOf(headerBytes, (byte)0, 1); // Find null terminator
-            Name = Encoding.UTF8.GetString(headerBytes, 2, nameEnd > 0 ? nameEnd - 2 : 12);
-
-            int offset = 15;
-            CompressedSize = BitConverter.ToUInt32(headerBytes, offset);
-            offset += 4;
-            uint rawDateTime = BitConverter.ToUInt32(headerBytes, offset);
-            DateTime = ConvertToDateTime(rawDateTime);
-            offset += 4;
-            Crc16 = BitConverter.ToUInt16(headerBytes, offset);
-            offset += 2;
-            OriginalSize = BitConverter.ToUInt32(headerBytes, offset);
-            return this;
-        }
-
-        private CompressionType GetCompressionType(byte value)
-        {
-            return value switch
-            {
-                1 or 2 => CompressionType.None,
-                3 => CompressionType.Packed,
-                4 => CompressionType.Squeezed,
-                5 or 6 or 7 or 8 => CompressionType.Crunched,
-                9 => CompressionType.Squashed,
-                10 => CompressionType.Crushed,
-                11 => CompressionType.Distilled,
-                _ => CompressionType.Unknown,
-            };
-        }
-
-        public static DateTime ConvertToDateTime(long rawDateTime)
-        {
-            // Convert Unix timestamp to DateTime (UTC)
-            return DateTimeOffset.FromUnixTimeSeconds(rawDateTime).UtcDateTime;
-        }
+    public static DateTime ConvertToDateTime(long rawDateTime)
+    {
+        // Convert Unix timestamp to DateTime (UTC)
+        return DateTimeOffset.FromUnixTimeSeconds(rawDateTime).UtcDateTime;
     }
 }

src/SharpCompress/Common/Arc/ArcFilePart.Async.cs

@@ -0,0 +1,58 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Compressors.Lzw;
+using SharpCompress.Compressors.RLE90;
+using SharpCompress.Compressors.Squeezed;
+using SharpCompress.IO;
+
+namespace SharpCompress.Common.Arc;
+
+public partial class ArcFilePart
+{
+    internal override async ValueTask<Stream?> GetCompressedStreamAsync(
+        CancellationToken cancellationToken = default
+    )
+    {
+        if (_stream != null)
+        {
+            Stream compressedStream;
+            switch (Header.CompressionMethod)
+            {
+                case CompressionType.None:
+                    compressedStream = new ReadOnlySubStream(
+                        _stream,
+                        Header.DataStartPosition,
+                        Header.CompressedSize
+                    );
+                    break;
+                case CompressionType.Packed:
+                    compressedStream = new RunLength90Stream(_stream, (int)Header.CompressedSize);
+                    break;
+                case CompressionType.Squeezed:
+                    compressedStream = await SqueezeStream.CreateAsync(
+                        _stream,
+                        (int)Header.CompressedSize,
+                        cancellationToken
+                    );
+                    break;
+                case CompressionType.Crunched:
+                    if (Header.OriginalSize > 128 * 1024)
+                    {
+                        throw new NotSupportedException(
+                            "CompressionMethod: " + Header.CompressionMethod + " with size > 128KB"
+                        );
+                    }
+                    compressedStream = new ArcLzwStream(_stream, (int)Header.CompressedSize, true);
+                    break;
+                default:
+                    throw new NotSupportedException(
+                        "CompressionMethod: " + Header.CompressionMethod
+                    );
+            }
+            return compressedStream;
+        }
+        return _stream;
+    }
+}

src/SharpCompress/Common/Arc/ArcFilePart.cs

@@ -13,71 +13,61 @@ using SharpCompress.Compressors.RLE90;
 using SharpCompress.Compressors.Squeezed;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Arc
+namespace SharpCompress.Common.Arc;
+
+public partial class ArcFilePart : FilePart
 {
-    public class ArcFilePart : FilePart
+    private readonly Stream? _stream;
+
+    internal ArcFilePart(ArcEntryHeader localArcHeader, Stream? seekableStream)
+        : base(localArcHeader.ArchiveEncoding)
     {
-        private readonly Stream? _stream;
-
-        internal ArcFilePart(ArcEntryHeader localArcHeader, Stream? seekableStream)
-            : base(localArcHeader.ArchiveEncoding)
-        {
-            _stream = seekableStream;
-            Header = localArcHeader;
-        }
-
-        internal ArcEntryHeader Header { get; set; }
-
-        internal override string? FilePartName => Header.Name;
-
-        internal override Stream GetCompressedStream()
-        {
-            if (_stream != null)
-            {
-                Stream compressedStream;
-                switch (Header.CompressionMethod)
-                {
-                    case CompressionType.None:
-                        compressedStream = new ReadOnlySubStream(
-                            _stream,
-                            Header.DataStartPosition,
-                            Header.CompressedSize
-                        );
-                        break;
-                    case CompressionType.Packed:
-                        compressedStream = new RunLength90Stream(
-                            _stream,
-                            (int)Header.CompressedSize
-                        );
-                        break;
-                    case CompressionType.Squeezed:
-                        compressedStream = new SqueezeStream(_stream, (int)Header.CompressedSize);
-                        break;
-                    case CompressionType.Crunched:
-                        if (Header.OriginalSize > 128 * 1024)
-                        {
-                            throw new NotSupportedException(
-                                "CompressionMethod: "
-                                    + Header.CompressionMethod
-                                    + " with size > 128KB"
-                            );
-                        }
-                        compressedStream = new ArcLzwStream(
-                            _stream,
-                            (int)Header.CompressedSize,
-                            true
-                        );
-                        break;
-                    default:
-                        throw new NotSupportedException(
-                            "CompressionMethod: " + Header.CompressionMethod
-                        );
-                }
-                return compressedStream;
-            }
-            return _stream.NotNull();
-        }
-
-        internal override Stream? GetRawStream() => _stream;
+        _stream = seekableStream;
+        Header = localArcHeader;
     }
+
+    internal ArcEntryHeader Header { get; set; }
+
+    internal override string? FilePartName => Header.Name;
+
+    internal override Stream GetCompressedStream()
+    {
+        if (_stream != null)
+        {
+            Stream compressedStream;
+            switch (Header.CompressionMethod)
+            {
+                case CompressionType.None:
+                    compressedStream = new ReadOnlySubStream(
+                        _stream,
+                        Header.DataStartPosition,
+                        Header.CompressedSize
+                    );
+                    break;
+                case CompressionType.Packed:
+                    compressedStream = new RunLength90Stream(_stream, (int)Header.CompressedSize);
+                    break;
+                case CompressionType.Squeezed:
+                    compressedStream = SqueezeStream.Create(_stream, (int)Header.CompressedSize);
+                    break;
+                case CompressionType.Crunched:
+                    if (Header.OriginalSize > 128 * 1024)
+                    {
+                        throw new NotSupportedException(
+                            "CompressionMethod: " + Header.CompressionMethod + " with size > 128KB"
+                        );
+                    }
+                    compressedStream = new ArcLzwStream(_stream, (int)Header.CompressedSize, true);
+                    break;
+                default:
+                    throw new NotSupportedException(
+                        "CompressionMethod: " + Header.CompressionMethod
+                    );
+            }
+            return compressedStream;
+        }
+        return _stream.NotNull();
+    }
+
+    internal override Stream? GetRawStream() => _stream;
 }

src/SharpCompress/Common/Arc/ArcVolume.cs

@@ -6,11 +6,10 @@ using System.Text;
 using System.Threading.Tasks;
 using SharpCompress.Readers;
 
-namespace SharpCompress.Common.Arc
+namespace SharpCompress.Common.Arc;
+
+public class ArcVolume : Volume
 {
-    public class ArcVolume : Volume
-    {
-        public ArcVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
-            : base(stream, readerOptions, index) { }
-    }
+    public ArcVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
+        : base(stream, readerOptions, index) { }
 }

src/SharpCompress/Common/Arj/ArjEntry.cs

@@ -6,53 +6,52 @@ using System.Threading.Tasks;
 using SharpCompress.Common.Arc;
 using SharpCompress.Common.Arj.Headers;
 
-namespace SharpCompress.Common.Arj
+namespace SharpCompress.Common.Arj;
+
+public class ArjEntry : Entry
 {
-    public class ArjEntry : Entry
+    private readonly ArjFilePart _filePart;
+
+    internal ArjEntry(ArjFilePart filePart)
     {
-        private readonly ArjFilePart _filePart;
-
-        internal ArjEntry(ArjFilePart filePart)
-        {
-            _filePart = filePart;
-        }
-
-        public override long Crc => _filePart.Header.OriginalCrc32;
-
-        public override string? Key => _filePart?.Header.Name;
-
-        public override string? LinkTarget => null;
-
-        public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
-
-        public override CompressionType CompressionType
-        {
-            get
-            {
-                if (_filePart.Header.CompressionMethod == CompressionMethod.Stored)
-                {
-                    return CompressionType.None;
-                }
-                return CompressionType.ArjLZ77;
-            }
-        }
-
-        public override long Size => _filePart?.Header.OriginalSize ?? 0;
-
-        public override DateTime? LastModifiedTime => _filePart.Header.DateTimeModified.DateTime;
-
-        public override DateTime? CreatedTime => _filePart.Header.DateTimeCreated.DateTime;
-
-        public override DateTime? LastAccessedTime => _filePart.Header.DateTimeAccessed.DateTime;
-
-        public override DateTime? ArchivedTime => null;
-
-        public override bool IsEncrypted => false;
-
-        public override bool IsDirectory => _filePart.Header.FileType == FileType.Directory;
-
-        public override bool IsSplitAfter => false;
-
-        internal override IEnumerable<FilePart> Parts => _filePart.Empty();
+        _filePart = filePart;
     }
+
+    public override long Crc => _filePart.Header.OriginalCrc32;
+
+    public override string? Key => _filePart?.Header.Name;
+
+    public override string? LinkTarget => null;
+
+    public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
+
+    public override CompressionType CompressionType
+    {
+        get
+        {
+            if (_filePart.Header.CompressionMethod == CompressionMethod.Stored)
+            {
+                return CompressionType.None;
+            }
+            return CompressionType.ArjLZ77;
+        }
+    }
+
+    public override long Size => _filePart?.Header.OriginalSize ?? 0;
+
+    public override DateTime? LastModifiedTime => _filePart.Header.DateTimeModified.DateTime;
+
+    public override DateTime? CreatedTime => _filePart.Header.DateTimeCreated.DateTime;
+
+    public override DateTime? LastAccessedTime => _filePart.Header.DateTimeAccessed.DateTime;
+
+    public override DateTime? ArchivedTime => null;
+
+    public override bool IsEncrypted => false;
+
+    public override bool IsDirectory => _filePart.Header.FileType == FileType.Directory;
+
+    public override bool IsSplitAfter => false;
+
+    internal override IEnumerable<FilePart> Parts => _filePart.Empty();
 }

src/SharpCompress/Common/Arj/ArjFilePart.cs

@@ -8,65 +8,62 @@ using SharpCompress.Common.Arj.Headers;
 using SharpCompress.Compressors.Arj;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Arj
+namespace SharpCompress.Common.Arj;
+
+public class ArjFilePart : FilePart
 {
-    public class ArjFilePart : FilePart
+    private readonly Stream _stream;
+    internal ArjLocalHeader Header { get; set; }
+
+    internal ArjFilePart(ArjLocalHeader localArjHeader, Stream seekableStream)
+        : base(localArjHeader.ArchiveEncoding)
     {
-        private readonly Stream _stream;
-        internal ArjLocalHeader Header { get; set; }
-
-        internal ArjFilePart(ArjLocalHeader localArjHeader, Stream seekableStream)
-            : base(localArjHeader.ArchiveEncoding)
-        {
-            _stream = seekableStream;
-            Header = localArjHeader;
-        }
-
-        internal override string? FilePartName => Header.Name;
-
-        internal override Stream GetCompressedStream()
-        {
-            if (_stream != null)
-            {
-                Stream compressedStream;
-                switch (Header.CompressionMethod)
-                {
-                    case CompressionMethod.Stored:
-                        compressedStream = new ReadOnlySubStream(
-                            _stream,
-                            Header.DataStartPosition,
-                            Header.CompressedSize
-                        );
-                        break;
-                    case CompressionMethod.CompressedMost:
-                    case CompressionMethod.Compressed:
-                    case CompressionMethod.CompressedFaster:
-                        if (Header.OriginalSize > 128 * 1024)
-                        {
-                            throw new NotSupportedException(
-                                "CompressionMethod: "
-                                    + Header.CompressionMethod
-                                    + " with size > 128KB"
-                            );
-                        }
-                        compressedStream = new LhaStream<Lh7DecoderCfg>(
-                            _stream,
-                            (int)Header.OriginalSize
-                        );
-                        break;
-                    case CompressionMethod.CompressedFastest:
-                        compressedStream = new LHDecoderStream(_stream, (int)Header.OriginalSize);
-                        break;
-                    default:
-                        throw new NotSupportedException(
-                            "CompressionMethod: " + Header.CompressionMethod
-                        );
-                }
-                return compressedStream;
-            }
-            return _stream.NotNull();
-        }
-
-        internal override Stream GetRawStream() => _stream;
+        _stream = seekableStream;
+        Header = localArjHeader;
     }
+
+    internal override string? FilePartName => Header.Name;
+
+    internal override Stream GetCompressedStream()
+    {
+        if (_stream != null)
+        {
+            Stream compressedStream;
+            switch (Header.CompressionMethod)
+            {
+                case CompressionMethod.Stored:
+                    compressedStream = new ReadOnlySubStream(
+                        _stream,
+                        Header.DataStartPosition,
+                        Header.CompressedSize
+                    );
+                    break;
+                case CompressionMethod.CompressedMost:
+                case CompressionMethod.Compressed:
+                case CompressionMethod.CompressedFaster:
+                    if (Header.OriginalSize > 128 * 1024)
+                    {
+                        throw new NotSupportedException(
+                            "CompressionMethod: " + Header.CompressionMethod + " with size > 128KB"
+                        );
+                    }
+                    compressedStream = new LhaStream<Lh7DecoderCfg>(
+                        _stream,
+                        (int)Header.OriginalSize
+                    );
+                    break;
+                case CompressionMethod.CompressedFastest:
+                    compressedStream = new LHDecoderStream(_stream, (int)Header.OriginalSize);
+                    break;
+                default:
+                    throw new NotSupportedException(
+                        "CompressionMethod: " + Header.CompressionMethod
+                    );
+            }
+            return compressedStream;
+        }
+        return _stream.NotNull();
+    }
+
+    internal override Stream GetRawStream() => _stream;
 }

src/SharpCompress/Common/Arj/ArjVolume.cs

@@ -8,29 +8,28 @@ using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
 using SharpCompress.Readers;
 
-namespace SharpCompress.Common.Arj
+namespace SharpCompress.Common.Arj;
+
+public class ArjVolume : Volume
 {
-    public class ArjVolume : Volume
+    public ArjVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
+        : base(stream, readerOptions, index) { }
+
+    public override bool IsFirstVolume
     {
-        public ArjVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
-            : base(stream, readerOptions, index) { }
+        get { return true; }
+    }
 
-        public override bool IsFirstVolume
-        {
-            get { return true; }
-        }
+    /// <summary>
+    /// ArjArchive is part of a multi-part archive.
+    /// </summary>
+    public override bool IsMultiVolume
+    {
+        get { return false; }
+    }
 
-        /// <summary>
-        /// ArjArchive is part of a multi-part archive.
-        /// </summary>
-        public override bool IsMultiVolume
-        {
-            get { return false; }
-        }
-
-        internal IEnumerable<ArjFilePart> GetVolumeFileParts()
-        {
-            return new List<ArjFilePart>();
-        }
+    internal IEnumerable<ArjFilePart> GetVolumeFileParts()
+    {
+        return new List<ArjFilePart>();
     }
 }

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

@@ -0,0 +1,132 @@
+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

@@ -3,156 +3,158 @@ 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;
 
-namespace SharpCompress.Common.Arj.Headers
+namespace SharpCompress.Common.Arj.Headers;
+
+public enum ArjHeaderType
 {
-    public enum ArjHeaderType
+    MainHeader,
+    LocalHeader,
+}
+
+public abstract partial class ArjHeader
+{
+    private const int FIRST_HDR_SIZE = 34;
+    private const ushort ARJ_MAGIC = 0xEA60;
+
+    public ArjHeader(ArjHeaderType type)
     {
-        MainHeader,
-        LocalHeader,
+        ArjHeaderType = type;
     }
 
-    public abstract class ArjHeader
-    {
-        private const int FIRST_HDR_SIZE = 34;
-        private const ushort ARJ_MAGIC = 0xEA60;
+    public ArjHeaderType ArjHeaderType { get; }
+    public byte Flags { get; set; }
+    public FileType FileType { get; set; }
 
-        public ArjHeader(ArjHeaderType type)
+    public abstract ArjHeader? Read(Stream reader);
+
+    // Async methods moved to ArjHeader.Async.cs
+
+    public byte[] ReadHeader(Stream stream)
+    {
+        // check for magic bytes
+        var magic = new byte[2];
+        if (stream.Read(magic) != 2)
         {
-            ArjHeaderType = type;
+            return Array.Empty<byte>();
         }
 
-        public ArjHeaderType ArjHeaderType { get; }
-        public byte Flags { get; set; }
-        public FileType FileType { get; set; }
-
-        public abstract ArjHeader? Read(Stream reader);
-
-        public byte[] ReadHeader(Stream stream)
+        if (!CheckMagicBytes(magic))
         {
-            // check for magic bytes
-            var magic = new byte[2];
-            if (stream.Read(magic) != 2)
+            throw new InvalidDataException("Not an ARJ file (wrong magic bytes)");
+        }
+
+        // read header_size
+        byte[] headerBytes = new byte[2];
+        stream.Read(headerBytes, 0, 2);
+        var headerSize = (ushort)(headerBytes[0] | headerBytes[1] << 8);
+        if (headerSize < 1)
+        {
+            return Array.Empty<byte>();
+        }
+
+        var body = new byte[headerSize];
+        var read = stream.Read(body, 0, headerSize);
+        if (read < headerSize)
+        {
+            return Array.Empty<byte>();
+        }
+
+        byte[] crc = new byte[4];
+        read = stream.Read(crc, 0, 4);
+        var checksum = Crc32Stream.Compute(body);
+        // Compute the hash value
+        if (checksum != BitConverter.ToUInt32(crc, 0))
+        {
+            throw new InvalidDataException("Header checksum is invalid");
+        }
+        return body;
+    }
+
+    // ReadHeaderAsync moved to ArjHeader.Async.cs
+
+    protected List<byte[]> ReadExtendedHeaders(Stream reader)
+    {
+        List<byte[]> extendedHeader = new List<byte[]>();
+        byte[] buffer = new byte[2];
+
+        while (true)
+        {
+            int bytesRead = reader.Read(buffer, 0, 2);
+            if (bytesRead < 2)
             {
-                return Array.Empty<byte>();
+                throw new EndOfStreamException(
+                    "Unexpected end of stream while reading extended header size."
+                );
             }
 
-            if (!CheckMagicBytes(magic))
+            var extHeaderSize = (ushort)(buffer[0] | (buffer[1] << 8));
+            if (extHeaderSize == 0)
             {
-                throw new InvalidDataException("Not an ARJ file (wrong magic bytes)");
+                return extendedHeader;
             }
 
-            // read header_size
-            byte[] headerBytes = new byte[2];
-            stream.Read(headerBytes, 0, 2);
-            var headerSize = (ushort)(headerBytes[0] | headerBytes[1] << 8);
-            if (headerSize < 1)
+            byte[] header = new byte[extHeaderSize];
+            bytesRead = reader.Read(header, 0, extHeaderSize);
+            if (bytesRead < extHeaderSize)
             {
-                return Array.Empty<byte>();
-            }
-
-            var body = new byte[headerSize];
-            var read = stream.Read(body, 0, headerSize);
-            if (read < headerSize)
-            {
-                return Array.Empty<byte>();
+                throw new EndOfStreamException(
+                    "Unexpected end of stream while reading extended header data."
+                );
             }
 
             byte[] crc = new byte[4];
-            read = stream.Read(crc, 0, 4);
-            var checksum = Crc32Stream.Compute(body);
-            // Compute the hash value
+            bytesRead = reader.Read(crc, 0, 4);
+            if (bytesRead < 4)
+            {
+                throw new EndOfStreamException(
+                    "Unexpected end of stream while reading extended header CRC."
+                );
+            }
+
+            var checksum = Crc32Stream.Compute(header);
             if (checksum != BitConverter.ToUInt32(crc, 0))
             {
-                throw new InvalidDataException("Header checksum is invalid");
-            }
-            return body;
-        }
-
-        protected List<byte[]> ReadExtendedHeaders(Stream reader)
-        {
-            List<byte[]> extendedHeader = new List<byte[]>();
-            byte[] buffer = new byte[2];
-
-            while (true)
-            {
-                int bytesRead = reader.Read(buffer, 0, 2);
-                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 = reader.Read(header, 0, extHeaderSize);
-                if (bytesRead < extHeaderSize)
-                {
-                    throw new EndOfStreamException(
-                        "Unexpected end of stream while reading extended header data."
-                    );
-                }
-
-                byte[] crc = new byte[4];
-                bytesRead = reader.Read(crc, 0, 4);
-                if (bytesRead < 4)
-                {
-                    throw new EndOfStreamException(
-                        "Unexpected end of stream while reading extended header CRC."
-                    );
-                }
-
-                var checksum = Crc32Stream.Compute(header);
-                if (checksum != BitConverter.ToUInt32(crc, 0))
-                {
-                    throw new InvalidDataException("Extended header checksum is invalid");
-                }
-
-                extendedHeader.Add(header);
-            }
-        }
-
-        // Flag helpers
-        public bool IsGabled => (Flags & 0x01) != 0;
-        public bool IsAnsiPage => (Flags & 0x02) != 0;
-        public bool IsVolume => (Flags & 0x04) != 0;
-        public bool IsArjProtected => (Flags & 0x08) != 0;
-        public bool IsPathSym => (Flags & 0x10) != 0;
-        public bool IsBackup => (Flags & 0x20) != 0;
-        public bool IsSecured => (Flags & 0x40) != 0;
-        public bool IsAltName => (Flags & 0x80) != 0;
-
-        public static FileType FileTypeFromByte(byte value)
-        {
-            return Enum.IsDefined(typeof(FileType), value)
-                ? (FileType)value
-                : Headers.FileType.Unknown;
-        }
-
-        public static bool IsArchive(Stream stream)
-        {
-            var bytes = new byte[2];
-            if (stream.Read(bytes, 0, 2) != 2)
-            {
-                return false;
+                throw new InvalidDataException("Extended header checksum is invalid");
             }
 
-            return CheckMagicBytes(bytes);
-        }
-
-        protected static bool CheckMagicBytes(byte[] headerBytes)
-        {
-            var magicValue = (ushort)(headerBytes[0] | headerBytes[1] << 8);
-            return magicValue == ARJ_MAGIC;
+            extendedHeader.Add(header);
         }
     }
+
+    // Flag helpers
+    public bool IsGabled => (Flags & 0x01) != 0;
+    public bool IsAnsiPage => (Flags & 0x02) != 0;
+    public bool IsVolume => (Flags & 0x04) != 0;
+    public bool IsArjProtected => (Flags & 0x08) != 0;
+    public bool IsPathSym => (Flags & 0x10) != 0;
+    public bool IsBackup => (Flags & 0x20) != 0;
+    public bool IsSecured => (Flags & 0x40) != 0;
+    public bool IsAltName => (Flags & 0x80) != 0;
+
+    public static FileType FileTypeFromByte(byte value)
+    {
+        return Enum.IsDefined(typeof(FileType), value) ? (FileType)value : Headers.FileType.Unknown;
+    }
+
+    public static bool IsArchive(Stream stream)
+    {
+        var bytes = new byte[2];
+        if (stream.Read(bytes, 0, 2) != 2)
+        {
+            return false;
+        }
+
+        return CheckMagicBytes(bytes);
+    }
+
+    protected static bool CheckMagicBytes(byte[] headerBytes)
+    {
+        var magicValue = (ushort)(headerBytes[0] | headerBytes[1] << 8);
+        return magicValue == ARJ_MAGIC;
+    }
 }

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

@@ -0,0 +1,24 @@
+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

@@ -4,158 +4,159 @@ 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
+namespace SharpCompress.Common.Arj.Headers;
+
+public partial class ArjLocalHeader : ArjHeader
 {
-    public class ArjLocalHeader : ArjHeader
+    public ArchiveEncoding ArchiveEncoding { get; }
+    public long DataStartPosition { get; protected set; }
+
+    public byte ArchiverVersionNumber { get; set; }
+    public byte MinVersionToExtract { get; set; }
+    public HostOS HostOS { get; set; }
+    public CompressionMethod CompressionMethod { get; set; }
+    public DosDateTime DateTimeModified { get; set; } = new DosDateTime(0);
+    public long CompressedSize { get; set; }
+    public long OriginalSize { get; set; }
+    public long OriginalCrc32 { get; set; }
+    public int FileSpecPosition { get; set; }
+    public int FileAccessMode { get; set; }
+    public byte FirstChapter { get; set; }
+    public byte LastChapter { get; set; }
+    public long ExtendedFilePosition { get; set; }
+    public DosDateTime DateTimeAccessed { get; set; } = new DosDateTime(0);
+    public DosDateTime DateTimeCreated { get; set; } = new DosDateTime(0);
+    public long OriginalSizeEvenForVolumes { get; set; }
+    public string Name { get; set; } = string.Empty;
+    public string Comment { get; set; } = string.Empty;
+
+    private const byte StdHdrSize = 30;
+    private const byte R9HdrSize = 46;
+
+    public ArjLocalHeader(ArchiveEncoding archiveEncoding)
+        : base(ArjHeaderType.LocalHeader)
     {
-        public ArchiveEncoding ArchiveEncoding { get; }
-        public long DataStartPosition { get; protected set; }
+        ArchiveEncoding =
+            archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+    }
 
-        public byte ArchiverVersionNumber { get; set; }
-        public byte MinVersionToExtract { get; set; }
-        public HostOS HostOS { get; set; }
-        public CompressionMethod CompressionMethod { get; set; }
-        public DosDateTime DateTimeModified { get; set; } = new DosDateTime(0);
-        public long CompressedSize { get; set; }
-        public long OriginalSize { get; set; }
-        public long OriginalCrc32 { get; set; }
-        public int FileSpecPosition { get; set; }
-        public int FileAccessMode { get; set; }
-        public byte FirstChapter { get; set; }
-        public byte LastChapter { get; set; }
-        public long ExtendedFilePosition { get; set; }
-        public DosDateTime DateTimeAccessed { get; set; } = new DosDateTime(0);
-        public DosDateTime DateTimeCreated { get; set; } = new DosDateTime(0);
-        public long OriginalSizeEvenForVolumes { get; set; }
-        public string Name { get; set; } = string.Empty;
-        public string Comment { get; set; } = string.Empty;
-
-        private const byte StdHdrSize = 30;
-        private const byte R9HdrSize = 46;
-
-        public ArjLocalHeader(ArchiveEncoding archiveEncoding)
-            : base(ArjHeaderType.LocalHeader)
+    public override ArjHeader? Read(Stream stream)
+    {
+        var body = ReadHeader(stream);
+        if (body.Length > 0)
         {
-            ArchiveEncoding =
-                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+            ReadExtendedHeaders(stream);
+            var header = LoadFrom(body);
+            header.DataStartPosition = stream.Position;
+            return header;
+        }
+        return null;
+    }
+
+    // ReadAsync moved to ArjLocalHeader.Async.cs
+
+    public ArjLocalHeader LoadFrom(byte[] headerBytes)
+    {
+        int offset = 0;
+
+        int ReadInt16()
+        {
+            if (offset + 1 >= headerBytes.Length)
+            {
+                throw new EndOfStreamException();
+            }
+            var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
+            offset += 2;
+            return v;
+        }
+        long ReadInt32()
+        {
+            if (offset + 3 >= headerBytes.Length)
+            {
+                throw new EndOfStreamException();
+            }
+            long v =
+                headerBytes[offset] & 0xFF
+                | (headerBytes[offset + 1] & 0xFF) << 8
+                | (headerBytes[offset + 2] & 0xFF) << 16
+                | (headerBytes[offset + 3] & 0xFF) << 24;
+            offset += 4;
+            return v;
         }
 
-        public override ArjHeader? Read(Stream stream)
+        byte headerSize = headerBytes[offset++];
+        ArchiverVersionNumber = headerBytes[offset++];
+        MinVersionToExtract = headerBytes[offset++];
+        HostOS hostOS = (HostOS)headerBytes[offset++];
+        Flags = headerBytes[offset++];
+        CompressionMethod = CompressionMethodFromByte(headerBytes[offset++]);
+        FileType = FileTypeFromByte(headerBytes[offset++]);
+
+        offset++; // Skip 1 byte
+
+        var rawTimestamp = ReadInt32();
+        DateTimeModified = rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+
+        CompressedSize = ReadInt32();
+        OriginalSize = ReadInt32();
+        OriginalCrc32 = ReadInt32();
+        FileSpecPosition = ReadInt16();
+        FileAccessMode = ReadInt16();
+
+        FirstChapter = headerBytes[offset++];
+        LastChapter = headerBytes[offset++];
+
+        ExtendedFilePosition = 0;
+        OriginalSizeEvenForVolumes = 0;
+
+        if (headerSize > StdHdrSize)
         {
-            var body = ReadHeader(stream);
-            if (body.Length > 0)
+            ExtendedFilePosition = ReadInt32();
+
+            if (headerSize >= R9HdrSize)
             {
-                ReadExtendedHeaders(stream);
-                var header = LoadFrom(body);
-                header.DataStartPosition = stream.Position;
-                return header;
+                rawTimestamp = ReadInt32();
+                DateTimeAccessed =
+                    rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+                rawTimestamp = ReadInt32();
+                DateTimeCreated =
+                    rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+                OriginalSizeEvenForVolumes = ReadInt32();
             }
-            return null;
         }
 
-        public ArjLocalHeader LoadFrom(byte[] headerBytes)
+        Name = Encoding.ASCII.GetString(
+            headerBytes,
+            offset,
+            Array.IndexOf(headerBytes, (byte)0, offset) - offset
+        );
+        offset += Name.Length + 1;
+
+        Comment = Encoding.ASCII.GetString(
+            headerBytes,
+            offset,
+            Array.IndexOf(headerBytes, (byte)0, offset) - offset
+        );
+        offset += Comment.Length + 1;
+
+        return this;
+    }
+
+    public static CompressionMethod CompressionMethodFromByte(byte value)
+    {
+        return value switch
         {
-            int offset = 0;
-
-            int ReadInt16()
-            {
-                if (offset + 1 >= headerBytes.Length)
-                {
-                    throw new EndOfStreamException();
-                }
-                var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
-                offset += 2;
-                return v;
-            }
-            long ReadInt32()
-            {
-                if (offset + 3 >= headerBytes.Length)
-                {
-                    throw new EndOfStreamException();
-                }
-                long v =
-                    headerBytes[offset] & 0xFF
-                    | (headerBytes[offset + 1] & 0xFF) << 8
-                    | (headerBytes[offset + 2] & 0xFF) << 16
-                    | (headerBytes[offset + 3] & 0xFF) << 24;
-                offset += 4;
-                return v;
-            }
-
-            byte headerSize = headerBytes[offset++];
-            ArchiverVersionNumber = headerBytes[offset++];
-            MinVersionToExtract = headerBytes[offset++];
-            HostOS hostOS = (HostOS)headerBytes[offset++];
-            Flags = headerBytes[offset++];
-            CompressionMethod = CompressionMethodFromByte(headerBytes[offset++]);
-            FileType = FileTypeFromByte(headerBytes[offset++]);
-
-            offset++; // Skip 1 byte
-
-            var rawTimestamp = ReadInt32();
-            DateTimeModified =
-                rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
-
-            CompressedSize = ReadInt32();
-            OriginalSize = ReadInt32();
-            OriginalCrc32 = ReadInt32();
-            FileSpecPosition = ReadInt16();
-            FileAccessMode = ReadInt16();
-
-            FirstChapter = headerBytes[offset++];
-            LastChapter = headerBytes[offset++];
-
-            ExtendedFilePosition = 0;
-            OriginalSizeEvenForVolumes = 0;
-
-            if (headerSize > StdHdrSize)
-            {
-                ExtendedFilePosition = ReadInt32();
-
-                if (headerSize >= R9HdrSize)
-                {
-                    rawTimestamp = ReadInt32();
-                    DateTimeAccessed =
-                        rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
-                    rawTimestamp = ReadInt32();
-                    DateTimeCreated =
-                        rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
-                    OriginalSizeEvenForVolumes = ReadInt32();
-                }
-            }
-
-            Name = Encoding.ASCII.GetString(
-                headerBytes,
-                offset,
-                Array.IndexOf(headerBytes, (byte)0, offset) - offset
-            );
-            offset += Name.Length + 1;
-
-            Comment = Encoding.ASCII.GetString(
-                headerBytes,
-                offset,
-                Array.IndexOf(headerBytes, (byte)0, offset) - offset
-            );
-            offset += Comment.Length + 1;
-
-            return this;
-        }
-
-        public static CompressionMethod CompressionMethodFromByte(byte value)
-        {
-            return value switch
-            {
-                0 => CompressionMethod.Stored,
-                1 => CompressionMethod.CompressedMost,
-                2 => CompressionMethod.Compressed,
-                3 => CompressionMethod.CompressedFaster,
-                4 => CompressionMethod.CompressedFastest,
-                8 => CompressionMethod.NoDataNoCrc,
-                9 => CompressionMethod.NoData,
-                _ => CompressionMethod.Unknown,
-            };
-        }
+            0 => CompressionMethod.Stored,
+            1 => CompressionMethod.CompressedMost,
+            2 => CompressionMethod.Compressed,
+            3 => CompressionMethod.CompressedFaster,
+            4 => CompressionMethod.CompressedFastest,
+            8 => CompressionMethod.NoDataNoCrc,
+            9 => CompressionMethod.NoData,
+            _ => CompressionMethod.Unknown,
+        };
     }
 }

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

@@ -0,0 +1,18 @@
+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

@@ -1,138 +1,141 @@
 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
+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;
+
+    public ArchiveEncoding ArchiveEncoding { get; }
+
+    public int ArchiverVersionNumber { get; private set; }
+    public int MinVersionToExtract { get; private set; }
+    public HostOS HostOs { get; private set; }
+    public int SecurityVersion { get; private set; }
+    public DosDateTime CreationDateTime { get; private set; } = new DosDateTime(0);
+    public long CompressedSize { get; private set; }
+    public long ArchiveSize { get; private set; }
+    public long SecurityEnvelope { get; private set; }
+    public int FileSpecPosition { get; private set; }
+    public int SecurityEnvelopeLength { get; private set; }
+    public int EncryptionVersion { get; private set; }
+    public int LastChapter { get; private set; }
+
+    public int ArjProtectionFactor { get; private set; }
+    public int Flags2 { get; private set; }
+    public string Name { get; private set; } = string.Empty;
+    public string Comment { get; private set; } = string.Empty;
+
+    public ArjMainHeader(ArchiveEncoding archiveEncoding)
+        : base(ArjHeaderType.MainHeader)
     {
-        private const int FIRST_HDR_SIZE = 34;
-        private const ushort ARJ_MAGIC = 0xEA60;
+        ArchiveEncoding =
+            archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+    }
 
-        public ArchiveEncoding ArchiveEncoding { get; }
+    public override ArjHeader? Read(Stream stream)
+    {
+        var body = ReadHeader(stream);
+        ReadExtendedHeaders(stream);
+        return LoadFrom(body);
+    }
 
-        public int ArchiverVersionNumber { get; private set; }
-        public int MinVersionToExtract { get; private set; }
-        public HostOS HostOs { get; private set; }
-        public int SecurityVersion { get; private set; }
-        public DosDateTime CreationDateTime { get; private set; } = new DosDateTime(0);
-        public long CompressedSize { get; private set; }
-        public long ArchiveSize { get; private set; }
-        public long SecurityEnvelope { get; private set; }
-        public int FileSpecPosition { get; private set; }
-        public int SecurityEnvelopeLength { get; private set; }
-        public int EncryptionVersion { get; private set; }
-        public int LastChapter { get; private set; }
+    // ReadAsync moved to ArjMainHeader.Async.cs
 
-        public int ArjProtectionFactor { get; private set; }
-        public int Flags2 { get; private set; }
-        public string Name { get; private set; } = string.Empty;
-        public string Comment { get; private set; } = string.Empty;
+    public ArjMainHeader LoadFrom(byte[] headerBytes)
+    {
+        var offset = 1;
 
-        public ArjMainHeader(ArchiveEncoding archiveEncoding)
-            : base(ArjHeaderType.MainHeader)
+        byte ReadByte()
         {
-            ArchiveEncoding =
-                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+            if (offset >= headerBytes.Length)
+            {
+                throw new EndOfStreamException();
+            }
+            return (byte)(headerBytes[offset++] & 0xFF);
         }
 
-        public override ArjHeader? Read(Stream stream)
+        int ReadInt16()
         {
-            var body = ReadHeader(stream);
-            ReadExtendedHeaders(stream);
-            return LoadFrom(body);
+            if (offset + 1 >= headerBytes.Length)
+            {
+                throw new EndOfStreamException();
+            }
+            var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
+            offset += 2;
+            return v;
         }
 
-        public ArjMainHeader LoadFrom(byte[] headerBytes)
+        long ReadInt32()
         {
-            var offset = 1;
-
-            byte ReadByte()
+            if (offset + 3 >= headerBytes.Length)
             {
-                if (offset >= headerBytes.Length)
-                {
-                    throw new EndOfStreamException();
-                }
-                return (byte)(headerBytes[offset++] & 0xFF);
+                throw new EndOfStreamException();
             }
+            long v =
+                headerBytes[offset] & 0xFF
+                | (headerBytes[offset + 1] & 0xFF) << 8
+                | (headerBytes[offset + 2] & 0xFF) << 16
+                | (headerBytes[offset + 3] & 0xFF) << 24;
+            offset += 4;
+            return v;
+        }
+        string ReadNullTerminatedString(byte[] x, int startIndex)
+        {
+            var result = new StringBuilder();
+            int i = startIndex;
 
-            int ReadInt16()
+            while (i < x.Length && x[i] != 0)
             {
-                if (offset + 1 >= headerBytes.Length)
-                {
-                    throw new EndOfStreamException();
-                }
-                var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
-                offset += 2;
-                return v;
-            }
-
-            long ReadInt32()
-            {
-                if (offset + 3 >= headerBytes.Length)
-                {
-                    throw new EndOfStreamException();
-                }
-                long v =
-                    headerBytes[offset] & 0xFF
-                    | (headerBytes[offset + 1] & 0xFF) << 8
-                    | (headerBytes[offset + 2] & 0xFF) << 16
-                    | (headerBytes[offset + 3] & 0xFF) << 24;
-                offset += 4;
-                return v;
-            }
-            string ReadNullTerminatedString(byte[] x, int startIndex)
-            {
-                var result = new StringBuilder();
-                int i = startIndex;
-
-                while (i < x.Length && x[i] != 0)
-                {
-                    result.Append((char)x[i]);
-                    i++;
-                }
-
-                // Skip the null terminator
+                result.Append((char)x[i]);
                 i++;
-                if (i < x.Length)
-                {
-                    byte[] remainder = new byte[x.Length - i];
-                    Array.Copy(x, i, remainder, 0, remainder.Length);
-                    x = remainder;
-                }
-
-                return result.ToString();
             }
 
-            ArchiverVersionNumber = ReadByte();
-            MinVersionToExtract = ReadByte();
+            // Skip the null terminator
+            i++;
+            if (i < x.Length)
+            {
+                byte[] remainder = new byte[x.Length - i];
+                Array.Copy(x, i, remainder, 0, remainder.Length);
+                x = remainder;
+            }
 
-            var hostOsByte = ReadByte();
-            HostOs = hostOsByte <= 11 ? (HostOS)hostOsByte : HostOS.Unknown;
-
-            Flags = ReadByte();
-            SecurityVersion = ReadByte();
-            FileType = FileTypeFromByte(ReadByte());
-
-            offset++; // skip reserved
-
-            CreationDateTime = new DosDateTime((int)ReadInt32());
-            CompressedSize = ReadInt32();
-            ArchiveSize = ReadInt32();
-
-            SecurityEnvelope = ReadInt32();
-            FileSpecPosition = ReadInt16();
-            SecurityEnvelopeLength = ReadInt16();
-
-            EncryptionVersion = ReadByte();
-            LastChapter = ReadByte();
-
-            Name = ReadNullTerminatedString(headerBytes, offset);
-            Comment = ReadNullTerminatedString(headerBytes, offset + 1 + Name.Length);
-
-            return this;
+            return result.ToString();
         }
+
+        ArchiverVersionNumber = ReadByte();
+        MinVersionToExtract = ReadByte();
+
+        var hostOsByte = ReadByte();
+        HostOs = hostOsByte <= 11 ? (HostOS)hostOsByte : HostOS.Unknown;
+
+        Flags = ReadByte();
+        SecurityVersion = ReadByte();
+        FileType = FileTypeFromByte(ReadByte());
+
+        offset++; // skip reserved
+
+        CreationDateTime = new DosDateTime((int)ReadInt32());
+        CompressedSize = ReadInt32();
+        ArchiveSize = ReadInt32();
+
+        SecurityEnvelope = ReadInt32();
+        FileSpecPosition = ReadInt16();
+        SecurityEnvelopeLength = ReadInt16();
+
+        EncryptionVersion = ReadByte();
+        LastChapter = ReadByte();
+
+        Name = ReadNullTerminatedString(headerBytes, offset);
+        Comment = ReadNullTerminatedString(headerBytes, offset + 1 + Name.Length);
+
+        return this;
     }
 }

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

@@ -4,17 +4,16 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Arj.Headers
+namespace SharpCompress.Common.Arj.Headers;
+
+public enum CompressionMethod
 {
-    public enum CompressionMethod
-    {
-        Stored = 0,
-        CompressedMost = 1,
-        Compressed = 2,
-        CompressedFaster = 3,
-        CompressedFastest = 4,
-        NoDataNoCrc = 8,
-        NoData = 9,
-        Unknown,
-    }
+    Stored = 0,
+    CompressedMost = 1,
+    Compressed = 2,
+    CompressedFaster = 3,
+    CompressedFastest = 4,
+    NoDataNoCrc = 8,
+    NoData = 9,
+    Unknown,
 }

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

@@ -1,37 +1,36 @@
 using System;
 
-namespace SharpCompress.Common.Arj.Headers
+namespace SharpCompress.Common.Arj.Headers;
+
+public class DosDateTime
 {
-    public class DosDateTime
+    public DateTime DateTime { get; }
+
+    public DosDateTime(long dosValue)
     {
-        public DateTime DateTime { get; }
+        // Ensure only the lower 32 bits are used
+        int value = unchecked((int)(dosValue & 0xFFFFFFFF));
 
-        public DosDateTime(long dosValue)
+        var date = (value >> 16) & 0xFFFF;
+        var time = value & 0xFFFF;
+
+        var day = date & 0x1F;
+        var month = (date >> 5) & 0x0F;
+        var year = ((date >> 9) & 0x7F) + 1980;
+
+        var second = (time & 0x1F) * 2;
+        var minute = (time >> 5) & 0x3F;
+        var hour = (time >> 11) & 0x1F;
+
+        try
         {
-            // Ensure only the lower 32 bits are used
-            int value = unchecked((int)(dosValue & 0xFFFFFFFF));
-
-            var date = (value >> 16) & 0xFFFF;
-            var time = value & 0xFFFF;
-
-            var day = date & 0x1F;
-            var month = (date >> 5) & 0x0F;
-            var year = ((date >> 9) & 0x7F) + 1980;
-
-            var second = (time & 0x1F) * 2;
-            var minute = (time >> 5) & 0x3F;
-            var hour = (time >> 11) & 0x1F;
-
-            try
-            {
-                DateTime = new DateTime(year, month, day, hour, minute, second);
-            }
-            catch
-            {
-                DateTime = DateTime.MinValue;
-            }
+            DateTime = new DateTime(year, month, day, hour, minute, second);
+        }
+        catch
+        {
+            DateTime = DateTime.MinValue;
         }
-
-        public override string ToString() => DateTime.ToString("yyyy-MM-dd HH:mm:ss");
     }
+
+    public override string ToString() => DateTime.ToString("yyyy-MM-dd HH:mm:ss");
 }

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

@@ -1,13 +1,12 @@
-namespace SharpCompress.Common.Arj.Headers
+namespace SharpCompress.Common.Arj.Headers;
+
+public enum FileType : byte
 {
-    public enum FileType : byte
-    {
-        Binary = 0,
-        Text7Bit = 1,
-        CommentHeader = 2,
-        Directory = 3,
-        VolumeLabel = 4,
-        ChapterLabel = 5,
-        Unknown = 255,
-    }
+    Binary = 0,
+    Text7Bit = 1,
+    CommentHeader = 2,
+    Directory = 3,
+    VolumeLabel = 4,
+    ChapterLabel = 5,
+    Unknown = 255,
 }

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

@@ -1,19 +1,18 @@
-namespace SharpCompress.Common.Arj.Headers
+namespace SharpCompress.Common.Arj.Headers;
+
+public enum HostOS
 {
-    public enum HostOS
-    {
-        MsDos = 0,
-        PrimOS = 1,
-        Unix = 2,
-        Amiga = 3,
-        MacOs = 4,
-        OS2 = 5,
-        AppleGS = 6,
-        AtariST = 7,
-        NeXT = 8,
-        VaxVMS = 9,
-        Win95 = 10,
-        Win32 = 11,
-        Unknown = 255,
-    }
+    MsDos = 0,
+    PrimOS = 1,
+    Unix = 2,
+    Amiga = 3,
+    MacOs = 4,
+    OS2 = 5,
+    AppleGS = 6,
+    AtariST = 7,
+    NeXT = 8,
+    VaxVMS = 9,
+    Win95 = 10,
+    Win32 = 11,
+    Unknown = 255,
 }

src/SharpCompress/Common/AsyncBinaryReader.cs

@@ -1,103 +0,0 @@
-using System;
-using System.Buffers.Binary;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common
-{
-    public sealed class AsyncBinaryReader : IDisposable
-    {
-        private readonly Stream _stream;
-        private readonly Stream _originalStream;
-        private readonly bool _leaveOpen;
-        private readonly byte[] _buffer = new byte[8];
-        private bool _disposed;
-
-        public AsyncBinaryReader(Stream stream, bool leaveOpen = false, int bufferSize = 4096)
-        {
-            _originalStream = stream ?? throw new ArgumentNullException(nameof(stream));
-            _leaveOpen = leaveOpen;
-
-            // Use the stream directly without wrapping in BufferedStream
-            // BufferedStream uses synchronous Read internally which doesn't work with async-only streams
-            // SharpCompress uses SharpCompressStream for buffering which supports true async reads
-            _stream = stream;
-        }
-
-        public Stream BaseStream => _stream;
-
-        public async ValueTask<byte> ReadByteAsync(CancellationToken ct = default)
-        {
-            await _stream.ReadExactAsync(_buffer, 0, 1, ct).ConfigureAwait(false);
-            return _buffer[0];
-        }
-
-        public async ValueTask<ushort> ReadUInt16Async(CancellationToken ct = default)
-        {
-            await _stream.ReadExactAsync(_buffer, 0, 2, ct).ConfigureAwait(false);
-            return BinaryPrimitives.ReadUInt16LittleEndian(_buffer);
-        }
-
-        public async ValueTask<uint> ReadUInt32Async(CancellationToken ct = default)
-        {
-            await _stream.ReadExactAsync(_buffer, 0, 4, ct).ConfigureAwait(false);
-            return BinaryPrimitives.ReadUInt32LittleEndian(_buffer);
-        }
-
-        public async ValueTask<ulong> ReadUInt64Async(CancellationToken ct = default)
-        {
-            await _stream.ReadExactAsync(_buffer, 0, 8, ct).ConfigureAwait(false);
-            return BinaryPrimitives.ReadUInt64LittleEndian(_buffer);
-        }
-
-        public async ValueTask ReadBytesAsync(
-            byte[] bytes,
-            int offset,
-            int count,
-            CancellationToken ct = default
-        )
-        {
-            await _stream.ReadExactAsync(bytes, offset, count, ct).ConfigureAwait(false);
-        }
-
-        public async ValueTask SkipAsync(int count, CancellationToken ct = default)
-        {
-            await _stream.SkipAsync(count, ct).ConfigureAwait(false);
-        }
-
-        public void Dispose()
-        {
-            if (_disposed)
-            {
-                return;
-            }
-
-            _disposed = true;
-
-            // Dispose the original stream if we own it
-            if (!_leaveOpen)
-            {
-                _originalStream.Dispose();
-            }
-        }
-
-#if NET8_0_OR_GREATER
-        public async ValueTask DisposeAsync()
-        {
-            if (_disposed)
-            {
-                return;
-            }
-
-            _disposed = true;
-
-            // Dispose the original stream if we own it
-            if (!_leaveOpen)
-            {
-                await _originalStream.DisposeAsync().ConfigureAwait(false);
-            }
-        }
-#endif
-    }
-}

src/SharpCompress/Common/Constants.cs

@@ -0,0 +1,41 @@
+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;
+
+    /// <summary>
+    /// The default size for rewindable buffers in SharpCompressStream.
+    /// Used for format detection on non-seekable streams.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// When opening archives from non-seekable streams (network streams, pipes,
+    /// compressed streams), SharpCompress uses a ring buffer to enable format
+    /// auto-detection. This buffer allows the library to try multiple decoders
+    /// by rewinding and re-reading the same data.
+    /// </para>
+    /// <para>
+    /// <b>Default:</b> 81920 bytes (81KB) - sufficient for typical format detection.
+    /// </para>
+    /// <para>
+    /// <b>Typical usage:</b> 500-1000 bytes for most archives
+    /// </para>
+    /// <para>
+    /// <b>Can be overridden per-stream via ReaderOptions.RewindableBufferSize.</b>
+    /// </para>
+    /// <para>
+    /// <b>Increase if:</b>
+    /// <list type="bullet">
+    /// <item>Handling self-extracting archives (may need 512KB+)</item>
+    /// <item>Format detection fails with buffer overflow errors</item>
+    /// <item>Using custom formats with large headers</item>
+    /// </list>
+    /// </para>
+    /// </remarks>
+    public static int RewindableBufferSize { get; set; } = 81920;
+}

src/SharpCompress/Common/EntryStream.Async.cs

@@ -0,0 +1,81 @@
+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);
+            }
+        }
+        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

@@ -8,28 +8,8 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Common;
 
-public class EntryStream : Stream, IStreamStack
+public partial class EntryStream : Stream
 {
-#if DEBUG_STREAMS
-    long IStreamStack.InstanceId { get; set; }
-#endif
-    int IStreamStack.DefaultBufferSize { get; set; }
-
-    Stream IStreamStack.BaseStream() => _stream;
-
-    int IStreamStack.BufferSize
-    {
-        get => 0;
-        set { }
-    }
-    int IStreamStack.BufferPosition
-    {
-        get => 0;
-        set { }
-    }
-
-    void IStreamStack.SetPosition(long position) { }
-
     private readonly IReader _reader;
     private readonly Stream _stream;
     private bool _completed;
@@ -39,9 +19,6 @@ public class EntryStream : Stream, IStreamStack
     {
         _reader = reader;
         _stream = stream;
-#if DEBUG_STREAMS
-        this.DebugConstruct(typeof(EntryStream));
-#endif
     }
 
     /// <summary>
@@ -53,15 +30,6 @@ public 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)
@@ -71,61 +39,38 @@ public class EntryStream : Stream, IStreamStack
         _isDisposed = true;
         if (!(_completed || _reader.Cancelled))
         {
-            SkipEntry();
+            if (Utility.UseSyncOverAsyncDispose())
+            {
+                SkipEntryAsync().GetAwaiter().GetResult();
+            }
+            else
+            {
+                SkipEntry();
+            }
         }
 
         //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)
+            if (
+                ss.GetStream<SharpCompress.Compressors.Deflate.DeflateStream>()
+                is SharpCompress.Compressors.Deflate.DeflateStream deflateStream
+            )
             {
                 deflateStream.Flush(); //Deflate over reads. Knock it back
             }
-            else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
+            else if (
+                ss.GetStream<SharpCompress.Compressors.LZMA.LzmaStream>()
+                is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream
+            )
             {
                 lzmaStream.Flush(); //Lzma over reads. Knock it back
             }
         }
-#if DEBUG_STREAMS
-        this.DebugDispose(typeof(EntryStream));
-#endif
         base.Dispose(disposing);
         _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;
@@ -154,38 +99,6 @@ public 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

@@ -0,0 +1,116 @@
+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 class ExtractionMethods
+internal static partial class ExtractionMethods
 {
     /// <summary>
     /// Gets the appropriate StringComparison for path checks based on the file system.
@@ -123,111 +123,4 @@ internal static 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

@@ -0,0 +1,15 @@
+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 class GZipEntry : Entry
+public partial class GZipEntry : Entry
 {
     private readonly GZipFilePart? _filePart;
 
@@ -42,4 +42,6 @@ public 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

@@ -0,0 +1,133 @@
+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

@@ -2,15 +2,13 @@ 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 class GZipFilePart : FilePart
+internal sealed partial class GZipFilePart : FilePart
 {
     private string? _name;
     private readonly Stream _stream;
@@ -37,32 +35,6 @@ internal sealed 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;
 
@@ -75,7 +47,12 @@ internal sealed class GZipFilePart : FilePart
     internal override string? FilePartName => _name;
 
     internal override Stream GetCompressedStream() =>
-        new DeflateStream(_stream, CompressionMode.Decompress, CompressionLevel.Default);
+        new DeflateStream(
+            _stream,
+            CompressionMode.Decompress,
+            CompressionLevel.Default,
+            leaveOpen: true
+        );
 
     internal override Stream GetRawStream() => _stream;
 
@@ -89,16 +66,6 @@ internal sealed 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
@@ -151,61 +118,6 @@ internal sealed 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];
@@ -231,33 +143,4 @@ internal sealed 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
+public interface IVolume : IDisposable, IAsyncDisposable
 {
     int Index { get; }
 

src/SharpCompress/Common/Rar/AsyncMarkingBinaryReader.cs

@@ -0,0 +1,190 @@
+using System;
+using System.Buffers.Binary;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Common;
+using SharpCompress.IO;
+
+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

@@ -0,0 +1,45 @@
+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

@@ -0,0 +1,109 @@
+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();
+    }
+}