Add opt-in multi-threading support with SupportsMultiThreadedExtraction flag

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

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

.copilot-agent.yml

@@ -0,0 +1,7 @@
+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

@@ -0,0 +1,17 @@
+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

@@ -0,0 +1,25 @@
+# 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

@@ -0,0 +1,123 @@
+# 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

.github/workflows/performance-benchmarks.yml

@@ -1,50 +0,0 @@
-name: Performance Benchmarks
-
-on:
-  push:
-    branches:
-      - 'master'
-      - 'release'
-  pull_request:
-    branches:
-      - 'master'
-      - 'release'
-  workflow_dispatch:
-
-permissions:
-  contents: read
-
-jobs:
-  benchmark:
-    runs-on: ubuntu-latest
-    
-    steps:
-    - uses: actions/checkout@v6
-      with:
-        fetch-depth: 0
-    
-    - uses: actions/setup-dotnet@v5
-      with:
-        dotnet-version: 10.0.x
-    
-    - name: Build Performance Project
-      run: dotnet build tests/SharpCompress.Performance/SharpCompress.Performance.csproj --configuration Release
-    
-    - name: Run Benchmarks
-      run: dotnet run --project tests/SharpCompress.Performance/SharpCompress.Performance.csproj --configuration Release --no-build -- --filter "*" --exporters json markdown --artifacts benchmark-results
-      continue-on-error: true
-    
-    - name: Display Benchmark Results
-      if: always()
-      run: dotnet run --project build/build.csproj -- display-benchmark-results
-    
-    - name: Compare with Baseline
-      if: always()
-      run: dotnet run --project build/build.csproj -- compare-benchmark-results
-    
-    - name: Upload Benchmark Results
-      if: always()
-      uses: actions/upload-artifact@v6
-      with:
-        name: benchmark-results
-        path: benchmark-results/

.gitignore

@@ -17,10 +17,6 @@ tests/TestArchives/*/Scratch2
 tools
 .idea/
 artifacts/
-BenchmarkDotNet.Artifacts/
-baseline-artifacts/
-profiler-snapshots/
 
 .DS_Store
 *.snupkg
-benchmark-results/

AGENTS.md

@@ -179,58 +179,3 @@ SharpCompress supports multiple archive and compression formats:
 3. **Stream disposal** - Always set `LeaveStreamOpen` explicitly when needed (default is to close)
 4. **Tar + non-seekable stream** - Must provide file size or it will throw
 6. **Format detection** - Use `ReaderFactory.Open()` for auto-detection, test with actual archive files
-
-### Async Struct-Copy Bug in LZMA RangeCoder
-
-When implementing async methods on mutable `struct` types (like `BitEncoder` and `BitDecoder` in the LZMA RangeCoder), be aware that the async state machine copies the struct when `await` is encountered. This means mutations to struct fields after the `await` point may not persist back to the original struct stored in arrays or fields.
-
-**The Bug:**
-```csharp
-// BAD: async method on mutable struct
-public async ValueTask<uint> DecodeAsync(Decoder decoder, CancellationToken cancellationToken = default)
-{
-    var newBound = (decoder._range >> K_NUM_BIT_MODEL_TOTAL_BITS) * _prob;
-    if (decoder._code < newBound)
-    {
-        decoder._range = newBound;
-        _prob += (K_BIT_MODEL_TOTAL - _prob) >> K_NUM_MOVE_BITS;  // Mutates _prob
-        await decoder.Normalize2Async(cancellationToken).ConfigureAwait(false);  // Struct gets copied here
-        return 0;  // Original _prob update may be lost
-    }
-    // ...
-}
-```
-
-**The Fix:**
-Refactor async methods on mutable structs to perform all struct mutations synchronously before any `await`, or use a helper method to separate the await from the struct mutation:
-
-```csharp
-// GOOD: struct mutations happen synchronously, await is conditional
-public ValueTask<uint> DecodeAsync(Decoder decoder, CancellationToken cancellationToken = default)
-{
-    var newBound = (decoder._range >> K_NUM_BIT_MODEL_TOTAL_BITS) * _prob;
-    if (decoder._code < newBound)
-    {
-        decoder._range = newBound;
-        _prob += (K_BIT_MODEL_TOTAL - _prob) >> K_NUM_MOVE_BITS;  // All mutations complete
-        return DecodeAsyncHelper(decoder.Normalize2Async(cancellationToken), 0);  // Await in helper
-    }
-    decoder._range -= newBound;
-    decoder._code -= newBound;
-    _prob -= (_prob) >> K_NUM_MOVE_BITS;  // All mutations complete
-    return DecodeAsyncHelper(decoder.Normalize2Async(cancellationToken), 1);  // Await in helper
-}
-
-private static async ValueTask<uint> DecodeAsyncHelper(ValueTask normalizeTask, uint result)
-{
-    await normalizeTask.ConfigureAwait(false);
-    return result;
-}
-```
-
-**Why This Matters:**
-In LZMA, the `BitEncoder` and `BitDecoder` structs maintain adaptive probability models in their `_prob` field. When these structs are stored in arrays (e.g., `_models[m]`), the async state machine copy breaks the adaptive model, causing incorrect bit decoding and eventually `DataErrorException` exceptions.
-
-**Related Files:**
-- `src/SharpCompress/Compressors/LZMA/RangeCoder/RangeCoderBit.Async.cs` - Fixed
-- `src/SharpCompress/Compressors/LZMA/RangeCoder/RangeCoderBitTree.Async.cs` - Uses readonly structs, so this pattern doesn't apply

Directory.Packages.props

@@ -1,20 +1,20 @@
 <Project>
   <ItemGroup>
-    <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
     <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="2.5.16" />
+    <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.15" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.0" />
+    <PackageVersion Include="Microsoft.NET.ILLink.Task" Version="10.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Mono.Posix.NETStandard" Version="1.0.0" />
     <PackageVersion Include="SimpleExec" Version="13.0.0" />
     <PackageVersion Include="System.Text.Encoding.CodePages" Version="10.0.0" />
     <PackageVersion Include="System.Buffers" Version="4.6.1" />
     <PackageVersion Include="System.Memory" Version="4.6.3" />
-    <PackageVersion Include="xunit.v3" Version="3.2.2" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
-    <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="10.0.102" />
+    <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
     <GlobalPackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3" />
     <GlobalPackageReference
       Include="Microsoft.VisualStudio.Threading.Analyzers"

build/Program.cs

@@ -19,9 +19,6 @@ const string Publish = "publish";
 const string DetermineVersion = "determine-version";
 const string UpdateVersion = "update-version";
 const string PushToNuGet = "push-to-nuget";
-const string DisplayBenchmarkResults = "display-benchmark-results";
-const string CompareBenchmarkResults = "compare-benchmark-results";
-const string GenerateBaseline = "generate-baseline";
 
 Target(
     Clean,
@@ -213,249 +210,6 @@ Target(
     }
 );
 
-Target(
-    DisplayBenchmarkResults,
-    () =>
-    {
-        var githubStepSummary = Environment.GetEnvironmentVariable("GITHUB_STEP_SUMMARY");
-        var resultsDir = "benchmark-results/results";
-
-        if (!Directory.Exists(resultsDir))
-        {
-            Console.WriteLine("No benchmark results found.");
-            return;
-        }
-
-        var markdownFiles = Directory
-            .GetFiles(resultsDir, "*-report-github.md")
-            .OrderBy(f => f)
-            .ToList();
-
-        if (markdownFiles.Count == 0)
-        {
-            Console.WriteLine("No benchmark markdown reports found.");
-            return;
-        }
-
-        var output = new List<string> { "## Benchmark Results", "" };
-
-        foreach (var file in markdownFiles)
-        {
-            Console.WriteLine($"Processing {Path.GetFileName(file)}");
-            var content = File.ReadAllText(file);
-            output.Add(content);
-            output.Add("");
-        }
-
-        // Write to GitHub Step Summary if available
-        if (!string.IsNullOrEmpty(githubStepSummary))
-        {
-            File.AppendAllLines(githubStepSummary, output);
-            Console.WriteLine($"Benchmark results written to GitHub Step Summary");
-        }
-        else
-        {
-            // Write to console if not in GitHub Actions
-            foreach (var line in output)
-            {
-                Console.WriteLine(line);
-            }
-        }
-    }
-);
-
-Target(
-    CompareBenchmarkResults,
-    () =>
-    {
-        var githubStepSummary = Environment.GetEnvironmentVariable("GITHUB_STEP_SUMMARY");
-        var baselinePath = "tests/SharpCompress.Performance/baseline-results.md";
-        var resultsDir = "benchmark-results/results";
-
-        var output = new List<string> { "## Comparison with Baseline", "" };
-
-        if (!File.Exists(baselinePath))
-        {
-            Console.WriteLine("Baseline file not found");
-            output.Add("⚠️ Baseline file not found. Run `generate-baseline` to create it.");
-            WriteOutput(output, githubStepSummary);
-            return;
-        }
-
-        if (!Directory.Exists(resultsDir))
-        {
-            Console.WriteLine("No current benchmark results found.");
-            output.Add("⚠️ No current benchmark results found. Showing baseline only.");
-            output.Add("");
-            output.Add("### Baseline Results");
-            output.AddRange(File.ReadAllLines(baselinePath));
-            WriteOutput(output, githubStepSummary);
-            return;
-        }
-
-        var markdownFiles = Directory
-            .GetFiles(resultsDir, "*-report-github.md")
-            .OrderBy(f => f)
-            .ToList();
-
-        if (markdownFiles.Count == 0)
-        {
-            Console.WriteLine("No current benchmark markdown reports found.");
-            output.Add("⚠️ No current benchmark results found. Showing baseline only.");
-            output.Add("");
-            output.Add("### Baseline Results");
-            output.AddRange(File.ReadAllLines(baselinePath));
-            WriteOutput(output, githubStepSummary);
-            return;
-        }
-
-        Console.WriteLine("Parsing baseline results...");
-        var baselineMetrics = ParseBenchmarkResults(File.ReadAllText(baselinePath));
-
-        Console.WriteLine("Parsing current results...");
-        var currentText = string.Join("\n", markdownFiles.Select(f => File.ReadAllText(f)));
-        var currentMetrics = ParseBenchmarkResults(currentText);
-
-        Console.WriteLine("Comparing results...");
-        output.Add("### Performance Comparison");
-        output.Add("");
-        output.Add(
-            "| Benchmark | Baseline Mean | Current Mean | Change | Baseline Memory | Current Memory | Change |"
-        );
-        output.Add(
-            "|-----------|---------------|--------------|--------|-----------------|----------------|--------|"
-        );
-
-        var hasRegressions = false;
-        var hasImprovements = false;
-
-        foreach (var method in currentMetrics.Keys.Union(baselineMetrics.Keys).OrderBy(k => k))
-        {
-            var hasCurrent = currentMetrics.TryGetValue(method, out var current);
-            var hasBaseline = baselineMetrics.TryGetValue(method, out var baseline);
-
-            if (!hasCurrent)
-            {
-                output.Add(
-                    $"| {method} | {baseline!.Mean} | ❌ Missing | N/A | {baseline.Memory} | N/A | N/A |"
-                );
-                continue;
-            }
-
-            if (!hasBaseline)
-            {
-                output.Add(
-                    $"| {method} | ❌ New | {current!.Mean} | N/A | N/A | {current.Memory} | N/A |"
-                );
-                continue;
-            }
-
-            var timeChange = CalculateChange(baseline!.MeanValue, current!.MeanValue);
-            var memChange = CalculateChange(baseline.MemoryValue, current.MemoryValue);
-
-            var timeIcon =
-                timeChange > 25 ? "🔴"
-                : timeChange < -25 ? "🟢"
-                : "⚪";
-            var memIcon =
-                memChange > 25 ? "🔴"
-                : memChange < -25 ? "🟢"
-                : "⚪";
-
-            if (timeChange > 25 || memChange > 25)
-                hasRegressions = true;
-            if (timeChange < -25 || memChange < -25)
-                hasImprovements = true;
-
-            output.Add(
-                $"| {method} | {baseline.Mean} | {current.Mean} | {timeIcon} {timeChange:+0.0;-0.0;0}% | {baseline.Memory} | {current.Memory} | {memIcon} {memChange:+0.0;-0.0;0}% |"
-            );
-        }
-
-        output.Add("");
-        output.Add("**Legend:**");
-        output.Add("- 🔴 Regression (>25% slower/more memory)");
-        output.Add("- 🟢 Improvement (>25% faster/less memory)");
-        output.Add("- ⚪ No significant change");
-
-        if (hasRegressions)
-        {
-            output.Add("");
-            output.Add(
-                "⚠️ **Warning**: Performance regressions detected. Review the changes carefully."
-            );
-        }
-        else if (hasImprovements)
-        {
-            output.Add("");
-            output.Add("✅ Performance improvements detected!");
-        }
-        else
-        {
-            output.Add("");
-            output.Add("✅ Performance is stable compared to baseline.");
-        }
-
-        WriteOutput(output, githubStepSummary);
-    }
-);
-
-Target(
-    GenerateBaseline,
-    () =>
-    {
-        var perfProject = "tests/SharpCompress.Performance/SharpCompress.Performance.csproj";
-        var baselinePath = "tests/SharpCompress.Performance/baseline-results.md";
-        var artifactsDir = "baseline-artifacts";
-
-        Console.WriteLine("Building performance project...");
-        Run("dotnet", $"build {perfProject} --configuration Release");
-
-        Console.WriteLine("Running benchmarks to generate baseline...");
-        Run(
-            "dotnet",
-            $"run --project {perfProject} --configuration Release --no-build -- --filter \"*\" --exporters markdown --artifacts {artifactsDir}"
-        );
-
-        var resultsDir = Path.Combine(artifactsDir, "results");
-        if (!Directory.Exists(resultsDir))
-        {
-            Console.WriteLine("ERROR: No benchmark results generated.");
-            return;
-        }
-
-        var markdownFiles = Directory
-            .GetFiles(resultsDir, "*-report-github.md")
-            .OrderBy(f => f)
-            .ToList();
-
-        if (markdownFiles.Count == 0)
-        {
-            Console.WriteLine("ERROR: No markdown reports found.");
-            return;
-        }
-
-        Console.WriteLine($"Combining {markdownFiles.Count} benchmark reports...");
-        var baselineContent = new List<string>();
-
-        foreach (var file in markdownFiles)
-        {
-            var lines = File.ReadAllLines(file);
-            baselineContent.AddRange(lines.Select(l => l.Trim()).Where(l => l.StartsWith('|')));
-        }
-
-        File.WriteAllText(baselinePath, string.Join(Environment.NewLine, baselineContent));
-        Console.WriteLine($"Baseline written to {baselinePath}");
-
-        // Clean up artifacts directory
-        if (Directory.Exists(artifactsDir))
-        {
-            Directory.Delete(artifactsDir, true);
-            Console.WriteLine("Cleaned up artifacts directory.");
-        }
-    }
-);
-
 Target("default", [Publish], () => Console.WriteLine("Done!"));
 
 await RunTargetsAndExitAsync(args);
@@ -476,7 +230,7 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
     }
     else
     {
-        // Not tagged - create prerelease version
+        // Not tagged - create prerelease version based on next minor version
         var allTags = (await GetGitOutput("tag", "--list"))
             .Split('\n', StringSplitOptions.RemoveEmptyEntries)
             .Where(tag => Regex.IsMatch(tag.Trim(), @"^\d+\.\d+\.\d+$"))
@@ -486,22 +240,8 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
         var lastTag = allTags.OrderBy(tag => Version.Parse(tag)).LastOrDefault() ?? "0.0.0";
         var lastVersion = Version.Parse(lastTag);
 
-        // Determine version increment based on branch
-        var currentBranch = await GetCurrentBranch();
-        Version nextVersion;
-
-        if (currentBranch == "release")
-        {
-            // Release branch: increment patch version
-            nextVersion = new Version(lastVersion.Major, lastVersion.Minor, lastVersion.Build + 1);
-            Console.WriteLine($"Building prerelease for release branch (patch increment)");
-        }
-        else
-        {
-            // Master or other branches: increment minor version
-            nextVersion = new Version(lastVersion.Major, lastVersion.Minor + 1, 0);
-            Console.WriteLine($"Building prerelease for {currentBranch} branch (minor increment)");
-        }
+        // Increment minor version for next release
+        var nextVersion = new Version(lastVersion.Major, lastVersion.Minor + 1, 0);
 
         // Use commit count since the last version tag if available; otherwise, fall back to total count
         var revListArgs = allTags.Any() ? $"--count {lastTag}..HEAD" : "--count HEAD";
@@ -513,28 +253,6 @@ static async Task<(string version, bool isPrerelease)> GetVersion()
     }
 }
 
-static async Task<string> GetCurrentBranch()
-{
-    // In GitHub Actions, GITHUB_REF_NAME contains the branch name
-    var githubRefName = Environment.GetEnvironmentVariable("GITHUB_REF_NAME");
-    if (!string.IsNullOrEmpty(githubRefName))
-    {
-        return githubRefName;
-    }
-
-    // Fallback to git command for local builds
-    try
-    {
-        var (output, _) = await ReadAsync("git", "branch --show-current");
-        return output.Trim();
-    }
-    catch (Exception ex)
-    {
-        Console.WriteLine($"Warning: Could not determine current branch: {ex.Message}");
-        return "unknown";
-    }
-}
-
 static async Task<string> GetGitOutput(string command, string args)
 {
     try
@@ -548,142 +266,3 @@ static async Task<string> GetGitOutput(string command, string args)
         throw new Exception($"Git command failed: git {command} {args}\n{ex.Message}", ex);
     }
 }
-
-static void WriteOutput(List<string> output, string? githubStepSummary)
-{
-    if (!string.IsNullOrEmpty(githubStepSummary))
-    {
-        File.AppendAllLines(githubStepSummary, output);
-        Console.WriteLine("Comparison written to GitHub Step Summary");
-    }
-    else
-    {
-        foreach (var line in output)
-        {
-            Console.WriteLine(line);
-        }
-    }
-}
-
-static Dictionary<string, BenchmarkMetric> ParseBenchmarkResults(string markdown)
-{
-    var metrics = new Dictionary<string, BenchmarkMetric>();
-    var lines = markdown.Split('\n');
-
-    for (int i = 0; i < lines.Length; i++)
-    {
-        var line = lines[i].Trim();
-
-        // Look for table rows with benchmark data
-        if (line.StartsWith("|") && line.Contains("&#39;") && i > 0)
-        {
-            var parts = line.Split('|', StringSplitOptions.TrimEntries);
-            if (parts.Length >= 5)
-            {
-                var method = parts[1].Replace("&#39;", "'");
-                var meanStr = parts[2];
-
-                // Find Allocated column - it's usually the last column or labeled "Allocated"
-                string memoryStr = "N/A";
-                for (int j = parts.Length - 2; j >= 2; j--)
-                {
-                    if (
-                        parts[j].Contains("KB")
-                        || parts[j].Contains("MB")
-                        || parts[j].Contains("GB")
-                        || parts[j].Contains("B")
-                    )
-                    {
-                        memoryStr = parts[j];
-                        break;
-                    }
-                }
-
-                if (
-                    !method.Equals("Method", StringComparison.OrdinalIgnoreCase)
-                    && !string.IsNullOrWhiteSpace(method)
-                )
-                {
-                    var metric = new BenchmarkMetric
-                    {
-                        Method = method,
-                        Mean = meanStr,
-                        MeanValue = ParseTimeValue(meanStr),
-                        Memory = memoryStr,
-                        MemoryValue = ParseMemoryValue(memoryStr),
-                    };
-                    metrics[method] = metric;
-                }
-            }
-        }
-    }
-
-    return metrics;
-}
-
-static double ParseTimeValue(string timeStr)
-{
-    if (string.IsNullOrWhiteSpace(timeStr) || timeStr == "N/A" || timeStr == "NA")
-        return 0;
-
-    // Remove thousands separators and parse
-    timeStr = timeStr.Replace(",", "").Trim();
-
-    var match = Regex.Match(timeStr, @"([\d.]+)\s*(\w+)");
-    if (!match.Success)
-        return 0;
-
-    var value = double.Parse(match.Groups[1].Value);
-    var unit = match.Groups[2].Value.ToLower();
-
-    // Convert to microseconds for comparison
-    return unit switch
-    {
-        "s" => value * 1_000_000,
-        "ms" => value * 1_000,
-        "μs" or "us" => value,
-        "ns" => value / 1_000,
-        _ => value,
-    };
-}
-
-static double ParseMemoryValue(string memStr)
-{
-    if (string.IsNullOrWhiteSpace(memStr) || memStr == "N/A" || memStr == "NA")
-        return 0;
-
-    memStr = memStr.Replace(",", "").Trim();
-
-    var match = Regex.Match(memStr, @"([\d.]+)\s*(\w+)");
-    if (!match.Success)
-        return 0;
-
-    var value = double.Parse(match.Groups[1].Value);
-    var unit = match.Groups[2].Value.ToUpper();
-
-    // Convert to KB for comparison
-    return unit switch
-    {
-        "GB" => value * 1_024 * 1_024,
-        "MB" => value * 1_024,
-        "KB" => value,
-        "B" => value / 1_024,
-        _ => value,
-    };
-}
-
-static double CalculateChange(double baseline, double current)
-{
-    if (baseline == 0)
-        return 0;
-    return ((current - baseline) / baseline) * 100;
-}
-
-record BenchmarkMetric
-{
-    public string Method { get; init; } = "";
-    public string Mean { get; init; } = "";
-    public double MeanValue { get; init; }
-    public string Memory { get; init; } = "";
-    public double MemoryValue { get; init; }
-}

build/packages.lock.json

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

src/SharpCompress/Archives/AbstractArchive.Async.cs

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

src/SharpCompress/Archives/AbstractArchive.cs

@@ -7,7 +7,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
+public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IAsyncArchive
     where TEntry : IArchiveEntry
     where TVolume : IVolume
 {
@@ -16,10 +16,6 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     private bool _disposed;
     private readonly SourceStream? _sourceStream;
 
-    // Async fields - kept in original file per refactoring rules
-    private readonly LazyAsyncReadOnlyCollection<TVolume> _lazyVolumesAsync;
-    private readonly LazyAsyncReadOnlyCollection<TEntry> _lazyEntriesAsync;
-
     protected ReaderOptions ReaderOptions { get; }
 
     internal AbstractArchive(ArchiveType type, SourceStream sourceStream)
@@ -81,6 +77,16 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     protected virtual IAsyncEnumerable<TVolume> LoadVolumesAsync(SourceStream sourceStream) =>
         LoadVolumes(sourceStream).ToAsyncEnumerable();
 
+    protected virtual async IAsyncEnumerable<TEntry> LoadEntriesAsync(
+        IAsyncEnumerable<TVolume> volumes
+    )
+    {
+        foreach (var item in LoadEntries(await volumes.ToListAsync()))
+        {
+            yield return item;
+        }
+    }
+
     IEnumerable<IArchiveEntry> IArchive.Entries => Entries.Cast<IArchiveEntry>();
 
     IEnumerable<IVolume> IArchive.Volumes => _lazyVolumes.Cast<IVolume>();
@@ -139,6 +145,19 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
     /// </summary>
     public virtual bool IsEncrypted => false;
 
+    /// <summary>
+    /// Returns whether multi-threaded extraction is supported for this archive.
+    /// Multi-threading is supported when:
+    /// 1. The archive is opened from a FileInfo or file path (not a stream)
+    /// 2. Multi-threading is explicitly enabled in ReaderOptions
+    /// 3. The archive is not SOLID (SOLID archives should use sequential extraction)
+    /// </summary>
+    public virtual bool SupportsMultiThreadedExtraction =>
+        _sourceStream is not null
+        && _sourceStream.IsFileMode
+        && ReaderOptions.EnableMultiThreadedExtraction
+        && !IsSolid;
+
     /// <summary>
     /// The archive can find all the parts of the archive needed to fully extract the archive.  This forces the parsing of the entire archive.
     /// </summary>
@@ -150,4 +169,85 @@ public abstract partial class AbstractArchive<TEntry, TVolume> : IArchive, IAsyn
             return Entries.All(x => x.IsComplete);
         }
     }
+
+    #region Async Support
+
+    private readonly LazyAsyncReadOnlyCollection<TVolume> _lazyVolumesAsync;
+    private readonly LazyAsyncReadOnlyCollection<TEntry> _lazyEntriesAsync;
+
+    public virtual async ValueTask DisposeAsync()
+    {
+        if (!_disposed)
+        {
+            await foreach (var v in _lazyVolumesAsync)
+            {
+                v.Dispose();
+            }
+            foreach (var v in _lazyEntriesAsync.GetLoaded().Cast<Entry>())
+            {
+                v.Close();
+            }
+            _sourceStream?.Dispose();
+
+            _disposed = true;
+        }
+    }
+
+    private async ValueTask EnsureEntriesLoadedAsync()
+    {
+        await _lazyEntriesAsync.EnsureFullyLoaded();
+        await _lazyVolumesAsync.EnsureFullyLoaded();
+    }
+
+    public virtual IAsyncEnumerable<TEntry> EntriesAsync => _lazyEntriesAsync;
+
+    private async IAsyncEnumerable<IArchiveEntry> EntriesAsyncCast()
+    {
+        await foreach (var entry in EntriesAsync)
+        {
+            yield return entry;
+        }
+    }
+
+    IAsyncEnumerable<IArchiveEntry> IAsyncArchive.EntriesAsync => EntriesAsyncCast();
+
+    private async IAsyncEnumerable<IVolume> VolumesAsyncCast()
+    {
+        await foreach (var volume in VolumesAsync)
+        {
+            yield return volume;
+        }
+    }
+
+    public IAsyncEnumerable<IVolume> VolumesAsync => VolumesAsyncCast();
+
+    public async ValueTask<IAsyncReader> ExtractAllEntriesAsync()
+    {
+        if (!IsSolid && Type != ArchiveType.SevenZip)
+        {
+            throw new SharpCompressException(
+                "ExtractAllEntries can only be used on solid archives or 7Zip archives (which require random access)."
+            );
+        }
+        await EnsureEntriesLoadedAsync();
+        return await CreateReaderForSolidExtractionAsync();
+    }
+
+    public virtual ValueTask<bool> IsSolidAsync() => new(false);
+
+    public async ValueTask<bool> IsCompleteAsync()
+    {
+        await EnsureEntriesLoadedAsync();
+        return await EntriesAsync.AllAsync(x => x.IsComplete);
+    }
+
+    public async ValueTask<long> TotalSizeAsync() =>
+        await EntriesAsync.AggregateAsync(0L, (total, cf) => total + cf.CompressedSize);
+
+    public async ValueTask<long> TotalUncompressedSizeAsync() =>
+        await EntriesAsync.AggregateAsync(0L, (total, cf) => total + cf.Size);
+
+    public ValueTask<bool> IsEncryptedAsync() => new(IsEncrypted);
+
+    #endregion
 }

src/SharpCompress/Archives/AbstractWritableArchive.Async.cs

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

src/SharpCompress/Archives/AbstractWritableArchive.cs

@@ -10,7 +10,7 @@ using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
 
-public abstract partial class AbstractWritableArchive<TEntry, TVolume>
+public abstract class AbstractWritableArchive<TEntry, TVolume>
     : AbstractArchive<TEntry, TVolume>,
         IWritableArchive,
         IWritableAsyncArchive
@@ -84,12 +84,12 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         }
     }
 
-    void IWritableArchive.RemoveEntry(IArchiveEntry entry) => RemoveEntry((TEntry)entry);
+    void IWritableArchiveCommon.RemoveEntry(IArchiveEntry entry) => RemoveEntry((TEntry)entry);
 
     public TEntry AddEntry(string key, Stream source, long size = 0, DateTime? modified = null) =>
         AddEntry(key, source, false, size, modified);
 
-    IArchiveEntry IWritableArchive.AddEntry(
+    IArchiveEntry IWritableArchiveCommon.AddEntry(
         string key,
         Stream source,
         bool closeStream,
@@ -97,7 +97,7 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         DateTime? modified
     ) => AddEntry(key, source, closeStream, size, modified);
 
-    IArchiveEntry IWritableArchive.AddDirectoryEntry(string key, DateTime? modified) =>
+    IArchiveEntry IWritableArchiveCommon.AddDirectoryEntry(string key, DateTime? modified) =>
         AddDirectoryEntry(key, modified);
 
     public TEntry AddEntry(
@@ -140,24 +140,6 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         return false;
     }
 
-    ValueTask IWritableAsyncArchive.RemoveEntryAsync(IArchiveEntry entry) =>
-        RemoveEntryAsync((TEntry)entry);
-
-    async ValueTask<IArchiveEntry> IWritableAsyncArchive.AddEntryAsync(
-        string key,
-        Stream source,
-        bool closeStream,
-        long size,
-        DateTime? modified,
-        CancellationToken cancellationToken
-    ) => await AddEntryAsync(key, source, closeStream, size, modified, cancellationToken);
-
-    async ValueTask<IArchiveEntry> IWritableAsyncArchive.AddDirectoryEntryAsync(
-        string key,
-        DateTime? modified,
-        CancellationToken cancellationToken
-    ) => await AddDirectoryEntryAsync(key, modified, cancellationToken);
-
     public TEntry AddDirectoryEntry(string key, DateTime? modified = null)
     {
         if (key.Length > 0 && key[0] is '/' or '\\')
@@ -181,6 +163,18 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
         SaveTo(stream, options, OldEntries, newEntries);
     }
 
+    public async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    )
+    {
+        //reset streams of new entries
+        newEntries.Cast<IWritableArchiveEntry>().ForEach(x => x.Stream.Seek(0, SeekOrigin.Begin));
+        await SaveToAsync(stream, options, OldEntries, newEntries, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     protected TEntry CreateEntry(
         string key,
         Stream source,
@@ -218,7 +212,7 @@ public abstract partial class AbstractWritableArchive<TEntry, TVolume>
     protected abstract ValueTask SaveToAsync(
         Stream stream,
         WriterOptions options,
-        IAsyncEnumerable<TEntry> oldEntries,
+        IEnumerable<TEntry> oldEntries,
         IEnumerable<TEntry> newEntries,
         CancellationToken cancellationToken = default
     );

src/SharpCompress/Archives/ArchiveFactory.Async.cs

@@ -1,157 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.Common;
-using SharpCompress.Factories;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives;
-
-public static partial class ArchiveFactory
-{
-    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
-        Stream stream,
-        ReaderOptions? readerOptions = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        readerOptions ??= new ReaderOptions();
-        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

@@ -11,14 +11,27 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public static partial class ArchiveFactory
+public static 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
@@ -39,6 +52,16 @@ public static partial class ArchiveFactory
         return OpenArchive(new FileInfo(filePath), options);
     }
 
+    public static ValueTask<IAsyncArchive> OpenAsyncArchive(
+        string filePath,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return OpenAsyncArchive(new FileInfo(filePath), options, cancellationToken);
+    }
+
     public static IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? options = null)
     {
         options ??= new ReaderOptions { LeaveStreamOpen = false };
@@ -46,6 +69,18 @@ public static partial class ArchiveFactory
         return FindFactory<IArchiveFactory>(fileInfo).OpenArchive(fileInfo, options);
     }
 
+    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
+        FileInfo fileInfo,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        var factory = await FindFactoryAsync<IArchiveFactory>(fileInfo, cancellationToken);
+        return factory.OpenAsyncArchive(fileInfo, options, cancellationToken);
+    }
+
     public static IArchive OpenArchive(
         IEnumerable<FileInfo> fileInfos,
         ReaderOptions? options = null
@@ -70,6 +105,32 @@ public static partial class ArchiveFactory
         return FindFactory<IMultiArchiveFactory>(fileInfo).OpenArchive(filesArray, options);
     }
 
+    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
+        IEnumerable<FileInfo> fileInfos,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        fileInfos.NotNull(nameof(fileInfos));
+        var filesArray = fileInfos.ToArray();
+        if (filesArray.Length == 0)
+        {
+            throw new InvalidOperationException("No files to open");
+        }
+
+        var fileInfo = filesArray[0];
+        if (filesArray.Length == 1)
+        {
+            return await OpenAsyncArchive(fileInfo, options, cancellationToken);
+        }
+
+        fileInfo.NotNull(nameof(fileInfo));
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        var factory = await FindFactoryAsync<IMultiArchiveFactory>(fileInfo, cancellationToken);
+        return factory.OpenAsyncArchive(filesArray, options, cancellationToken);
+    }
+
     public static IArchive OpenArchive(IEnumerable<Stream> streams, ReaderOptions? options = null)
     {
         streams.NotNull(nameof(streams));
@@ -91,6 +152,33 @@ public static partial class ArchiveFactory
         return FindFactory<IMultiArchiveFactory>(firstStream).OpenArchive(streamsArray, options);
     }
 
+    public static async ValueTask<IAsyncArchive> OpenAsyncArchive(
+        IEnumerable<Stream> streams,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        streams.NotNull(nameof(streams));
+        var streamsArray = streams.ToArray();
+        if (streamsArray.Length == 0)
+        {
+            throw new InvalidOperationException("No streams");
+        }
+
+        var firstStream = streamsArray[0];
+        if (streamsArray.Length == 1)
+        {
+            return await OpenAsyncArchive(firstStream, options, cancellationToken);
+        }
+
+        firstStream.NotNull(nameof(firstStream));
+        options ??= new ReaderOptions();
+
+        var factory = FindFactory<IMultiArchiveFactory>(firstStream);
+        return factory.OpenAsyncArchive(streamsArray, options);
+    }
+
     public static void WriteToDirectory(
         string sourceArchive,
         string destinationDirectory,
@@ -101,15 +189,7 @@ public static partial class ArchiveFactory
         archive.WriteToDirectory(destinationDirectory, options);
     }
 
-    public static T FindFactory<T>(string path)
-        where T : IFactory
-    {
-        path.NotNullOrEmpty(nameof(path));
-        using Stream stream = File.OpenRead(path);
-        return FindFactory<T>(stream);
-    }
-
-    public static T FindFactory<T>(FileInfo finfo)
+    private static T FindFactory<T>(FileInfo finfo)
         where T : IFactory
     {
         finfo.NotNull(nameof(finfo));
@@ -117,7 +197,7 @@ public static partial class ArchiveFactory
         return FindFactory<T>(stream);
     }
 
-    public static T FindFactory<T>(Stream stream)
+    private static T FindFactory<T>(Stream stream)
         where T : IFactory
     {
         stream.NotNull(nameof(stream));
@@ -149,14 +229,68 @@ public static partial class ArchiveFactory
         );
     }
 
-    public static bool IsArchive(string filePath, out ArchiveType? type)
+    private static async ValueTask<T> FindFactoryAsync<T>(
+        FileInfo finfo,
+        CancellationToken cancellationToken
+    )
+        where T : IFactory
+    {
+        finfo.NotNull(nameof(finfo));
+        using Stream stream = finfo.OpenRead();
+        return await FindFactoryAsync<T>(stream, cancellationToken);
+    }
+
+    private static async ValueTask<T> FindFactoryAsync<T>(
+        Stream stream,
+        CancellationToken cancellationToken
+    )
+        where T : IFactory
+    {
+        stream.NotNull(nameof(stream));
+        if (!stream.CanRead || !stream.CanSeek)
+        {
+            throw new ArgumentException("Stream should be readable and seekable");
+        }
+
+        var factories = Factory.Factories.OfType<T>();
+
+        var startPosition = stream.Position;
+
+        foreach (var factory in factories)
+        {
+            stream.Seek(startPosition, SeekOrigin.Begin);
+
+            if (await factory.IsArchiveAsync(stream, cancellationToken: cancellationToken))
+            {
+                stream.Seek(startPosition, SeekOrigin.Begin);
+
+                return factory;
+            }
+        }
+
+        var extensions = string.Join(", ", factories.Select(item => item.Name));
+
+        throw new InvalidOperationException(
+            $"Cannot determine compressed stream type. Supported Archive Formats: {extensions}"
+        );
+    }
+
+    public static bool IsArchive(
+        string filePath,
+        out ArchiveType? type,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         filePath.NotNullOrEmpty(nameof(filePath));
         using Stream s = File.OpenRead(filePath);
-        return IsArchive(s, out type);
+        return IsArchive(s, out type, bufferSize);
     }
 
-    public static bool IsArchive(Stream stream, out ArchiveType? type)
+    public static bool IsArchive(
+        Stream stream,
+        out ArchiveType? type,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         type = null;
         stream.NotNull(nameof(stream));
@@ -211,4 +345,6 @@ public static partial class ArchiveFactory
             }
         }
     }
+
+    public static IArchiveFactory AutoFactory { get; } = new AutoArchiveFactory();
 }

src/SharpCompress/Archives/ArchiveVolumeFactory.cs

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

src/SharpCompress/Archives/AutoArchiveFactory.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Common;
+using SharpCompress.Readers;
+
+namespace SharpCompress.Archives;
+
+internal class AutoArchiveFactory : IArchiveFactory
+{
+    public string Name => nameof(AutoArchiveFactory);
+
+    public ArchiveType? KnownArchiveType => null;
+
+    public IEnumerable<string> GetSupportedExtensions() => throw new NotSupportedException();
+
+    public bool IsArchive(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    ) => throw new NotSupportedException();
+
+    public ValueTask<bool> IsArchiveAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    ) => throw new NotSupportedException();
+
+    public FileInfo? GetFilePart(int index, FileInfo part1) => throw new NotSupportedException();
+
+    public IArchive OpenArchive(Stream stream, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.OpenArchive(stream, readerOptions);
+
+    public IAsyncArchive OpenAsyncArchive(Stream stream, ReaderOptions? readerOptions = null) =>
+        (IAsyncArchive)OpenArchive(stream, readerOptions);
+
+    public IArchive OpenArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.OpenArchive(fileInfo, readerOptions);
+
+    public IAsyncArchive OpenAsyncArchive(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return (IAsyncArchive)OpenArchive(fileInfo, readerOptions);
+    }
+}

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

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

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

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

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -36,6 +36,19 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         SaveTo(stream, new WriterOptions(CompressionType.GZip));
     }
 
+    public ValueTask SaveToAsync(string filePath, CancellationToken cancellationToken = default) =>
+        SaveToAsync(new FileInfo(filePath), cancellationToken);
+
+    public async ValueTask SaveToAsync(
+        FileInfo fileInfo,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        await SaveToAsync(stream, new WriterOptions(CompressionType.GZip), cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     protected override GZipArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -79,6 +92,28 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<GZipArchiveEntry> oldEntries,
+        IEnumerable<GZipArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        if (Entries.Count > 1)
+        {
+            throw new InvalidFormatException("Only one entry is allowed in a GZip Archive");
+        }
+        using var writer = new GZipWriter(stream, new GZipWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries).Where(x => !x.IsDirectory))
+        {
+            using var entryStream = entry.OpenEntryStream();
+            await writer
+                .WriteAsync(entry.Key.NotNull("Entry Key is null"), entryStream, cancellationToken)
+                .ConfigureAwait(false);
+        }
+    }
+
     protected override IEnumerable<GZipArchiveEntry> LoadEntries(IEnumerable<GZipVolume> volumes)
     {
         var stream = volumes.Single().Stream;
@@ -88,10 +123,28 @@ public partial class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZi
         );
     }
 
+    protected override async IAsyncEnumerable<GZipArchiveEntry> LoadEntriesAsync(
+        IAsyncEnumerable<GZipVolume> volumes
+    )
+    {
+        var stream = (await volumes.SingleAsync()).Stream;
+        yield return new GZipArchiveEntry(
+            this,
+            await GZipFilePart.CreateAsync(stream, ReaderOptions.ArchiveEncoding)
+        );
+    }
+
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
         return GZipReader.OpenReader(stream);
     }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new((IAsyncReader)GZipReader.OpenReader(stream));
+    }
 }

src/SharpCompress/Archives/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.CreateNonDisposing(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()

src/SharpCompress/Archives/IArchive.cs

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

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -9,6 +9,8 @@ namespace SharpCompress.Archives;
 
 public static class IArchiveEntryExtensions
 {
+    private const int BufferSize = 81920;
+
     /// <param name="archiveEntry">The archive entry to extract.</param>
     extension(IArchiveEntry archiveEntry)
     {
@@ -26,7 +28,7 @@ public static class IArchiveEntryExtensions
 
             using var entryStream = archiveEntry.OpenEntryStream();
             var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
-            sourceStream.CopyTo(streamToWriteTo, Constants.BufferSize);
+            sourceStream.CopyTo(streamToWriteTo, BufferSize);
         }
 
         /// <summary>
@@ -46,16 +48,10 @@ 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, Constants.BufferSize, cancellationToken)
+                .CopyToAsync(streamToWriteTo, BufferSize, cancellationToken)
                 .ConfigureAwait(false);
         }
     }

src/SharpCompress/Archives/IArchiveFactory.cs

@@ -47,5 +47,9 @@ public interface IArchiveFactory : IFactory
     /// <param name="fileInfo">the file to open.</param>
     /// <param name="readerOptions">reading options.</param>
     /// <param name="cancellationToken">Cancellation token.</param>
-    IAsyncArchive OpenAsyncArchive(FileInfo fileInfo, ReaderOptions? readerOptions = null);
+    IAsyncArchive OpenAsyncArchive(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 }

src/SharpCompress/Archives/IAsyncArchiveExtensions.cs

@@ -20,7 +20,7 @@ public static class IAsyncArchiveExtensions
         /// <param name="options">Extraction options.</param>
         /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
         /// <param name="cancellationToken">Optional cancellation token.</param>
-        public async ValueTask WriteToDirectoryAsync(
+        public async Task WriteToDirectoryAsync(
             string destinationDirectory,
             ExtractionOptions? options = null,
             IProgress<ProgressReport>? progress = null,
@@ -47,7 +47,7 @@ public static class IAsyncArchiveExtensions
             }
         }
 
-        private async ValueTask WriteToDirectoryAsyncInternal(
+        private async Task WriteToDirectoryAsyncInternal(
             string destinationDirectory,
             ExtractionOptions? options,
             IProgress<ProgressReport>? progress,

src/SharpCompress/Archives/IWritableArchive.cs

@@ -13,10 +13,12 @@ public interface IWritableArchiveCommon
     /// </summary>
     /// <returns>IDisposeable to resume entry rebuilding</returns>
     IDisposable PauseEntryRebuilding();
-}
 
-public interface IWritableArchive : IArchive, IWritableArchiveCommon
-{
+    /// <summary>
+    /// Removes the specified entry from the archive.
+    /// </summary>
+    void RemoveEntry(IArchiveEntry entry);
+
     IArchiveEntry AddEntry(
         string key,
         Stream source,
@@ -26,16 +28,14 @@ public interface IWritableArchive : IArchive, IWritableArchiveCommon
     );
 
     IArchiveEntry AddDirectoryEntry(string key, DateTime? modified = null);
+}
 
+public interface IWritableArchive : IArchive, IWritableArchiveCommon
+{
     /// <summary>
     /// Saves the archive to the specified stream using the given writer options.
     /// </summary>
     void SaveTo(Stream stream, WriterOptions options);
-
-    /// <summary>
-    /// Removes the specified entry from the archive.
-    /// </summary>
-    void RemoveEntry(IArchiveEntry entry);
 }
 
 public interface IWritableAsyncArchive : IAsyncArchive, IWritableArchiveCommon
@@ -48,30 +48,4 @@ public interface IWritableAsyncArchive : IAsyncArchive, IWritableArchiveCommon
         WriterOptions options,
         CancellationToken cancellationToken = default
     );
-
-    /// <summary>
-    /// Asynchronously adds an entry to the archive with the specified key, source stream, and options.
-    /// </summary>
-    ValueTask<IArchiveEntry> AddEntryAsync(
-        string key,
-        Stream source,
-        bool closeStream,
-        long size = 0,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    );
-
-    /// <summary>
-    /// Asynchronously adds a directory entry to the archive with the specified key and modification time.
-    /// </summary>
-    ValueTask<IArchiveEntry> AddDirectoryEntryAsync(
-        string key,
-        DateTime? modified = null,
-        CancellationToken cancellationToken = default
-    );
-
-    /// <summary>
-    /// Removes the specified entry from the archive.
-    /// </summary>
-    ValueTask RemoveEntryAsync(IArchiveEntry entry);
 }

src/SharpCompress/Archives/IWritableArchiveCommonExtensions.cs

@@ -0,0 +1,59 @@
+using System;
+using System.IO;
+
+namespace SharpCompress.Archives;
+
+public static class IWritableArchiveCommonExtensions
+{
+    extension(IWritableArchiveCommon writableArchive)
+    {
+        public void AddAllFromDirectory(
+            string filePath,
+            string searchPattern = "*.*",
+            SearchOption searchOption = SearchOption.AllDirectories
+        )
+        {
+            using (writableArchive.PauseEntryRebuilding())
+            {
+                foreach (
+                    var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption)
+                )
+                {
+                    var fileInfo = new FileInfo(path);
+                    writableArchive.AddEntry(
+                        path.Substring(filePath.Length),
+                        fileInfo.OpenRead(),
+                        true,
+                        fileInfo.Length,
+                        fileInfo.LastWriteTime
+                    );
+                }
+            }
+        }
+
+        public IArchiveEntry AddEntry(string key, string file) =>
+            writableArchive.AddEntry(key, new FileInfo(file));
+
+        public IArchiveEntry AddEntry(
+            string key,
+            Stream source,
+            long size = 0,
+            DateTime? modified = null
+        ) => writableArchive.AddEntry(key, source, false, size, modified);
+
+        public IArchiveEntry AddEntry(string key, FileInfo fileInfo)
+        {
+            if (!fileInfo.Exists)
+            {
+                throw new ArgumentException("FileInfo does not exist.");
+            }
+            return writableArchive.AddEntry(
+                key,
+                fileInfo.OpenRead(),
+                true,
+                fileInfo.Length,
+                fileInfo.LastWriteTime
+            );
+        }
+    }
+}

src/SharpCompress/Archives/IWritableArchiveExtensions.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Writers;
@@ -9,55 +8,6 @@ public static class IWritableArchiveExtensions
 {
     extension(IWritableArchive writableArchive)
     {
-        public void AddAllFromDirectory(
-            string filePath,
-            string searchPattern = "*.*",
-            SearchOption searchOption = SearchOption.AllDirectories
-        )
-        {
-            using (writableArchive.PauseEntryRebuilding())
-            {
-                foreach (
-                    var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption)
-                )
-                {
-                    var fileInfo = new FileInfo(path);
-                    writableArchive.AddEntry(
-                        path.Substring(filePath.Length),
-                        fileInfo.OpenRead(),
-                        true,
-                        fileInfo.Length,
-                        fileInfo.LastWriteTime
-                    );
-                }
-            }
-        }
-
-        public IArchiveEntry AddEntry(string key, string file) =>
-            writableArchive.AddEntry(key, new FileInfo(file));
-
-        public IArchiveEntry AddEntry(
-            string key,
-            Stream source,
-            long size = 0,
-            DateTime? modified = null
-        ) => writableArchive.AddEntry(key, source, false, size, modified);
-
-        public IArchiveEntry AddEntry(string key, FileInfo fileInfo)
-        {
-            if (!fileInfo.Exists)
-            {
-                throw new ArgumentException("FileInfo does not exist.");
-            }
-            return writableArchive.AddEntry(
-                key,
-                fileInfo.OpenRead(),
-                true,
-                fileInfo.Length,
-                fileInfo.LastWriteTime
-            );
-        }
-
         public void SaveTo(string filePath, WriterOptions? options = null) =>
             writableArchive.SaveTo(new FileInfo(filePath), options ?? new(CompressionType.Deflate));
 

src/SharpCompress/Archives/IWritableAsyncArchiveExtensions.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -11,55 +10,6 @@ public static class IWritableAsyncArchiveExtensions
 {
     extension(IWritableAsyncArchive writableArchive)
     {
-        public async ValueTask AddAllFromDirectoryAsync(
-            string filePath,
-            string searchPattern = "*.*",
-            SearchOption searchOption = SearchOption.AllDirectories
-        )
-        {
-            using (writableArchive.PauseEntryRebuilding())
-            {
-                foreach (
-                    var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption)
-                )
-                {
-                    var fileInfo = new FileInfo(path);
-                    await writableArchive.AddEntryAsync(
-                        path.Substring(filePath.Length),
-                        fileInfo.OpenRead(),
-                        true,
-                        fileInfo.Length,
-                        fileInfo.LastWriteTime
-                    );
-                }
-            }
-        }
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(string key, string file) =>
-            writableArchive.AddEntryAsync(key, new FileInfo(file));
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(
-            string key,
-            Stream source,
-            long size = 0,
-            DateTime? modified = null
-        ) => writableArchive.AddEntryAsync(key, source, false, size, modified);
-
-        public ValueTask<IArchiveEntry> AddEntryAsync(string key, FileInfo fileInfo)
-        {
-            if (!fileInfo.Exists)
-            {
-                throw new ArgumentException("FileInfo does not exist.");
-            }
-            return writableArchive.AddEntryAsync(
-                key,
-                fileInfo.OpenRead(),
-                true,
-                fileInfo.Length,
-                fileInfo.LastWriteTime
-            );
-        }
-
         public ValueTask SaveToAsync(
             string filePath,
             WriterOptions? options = null,

src/SharpCompress/Archives/Rar/FileInfoRarArchiveVolume.cs

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

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

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

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

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
@@ -164,24 +163,4 @@ public partial class RarArchive
             return false;
         }
     }
-
-    public static async ValueTask<bool> IsRarFileAsync(
-        Stream stream,
-        ReaderOptions? options = null,
-        CancellationToken cancellationToken = default
-    )
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        try
-        {
-            await MarkHeader
-                .ReadAsync(stream, true, false, cancellationToken)
-                .ConfigureAwait(false);
-            return true;
-        }
-        catch
-        {
-            return false;
-        }
-    }
 }

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -24,10 +24,7 @@ public interface IRarArchive : IArchive, IRarArchiveCommon { }
 
 public interface IRarAsyncArchive : IAsyncArchive, IRarArchiveCommon { }
 
-public partial class RarArchive
-    : AbstractArchive<RarArchiveEntry, RarVolume>,
-        IRarArchive,
-        IRarAsyncArchive
+public partial class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>, IRarArchive
 {
     private bool _disposed;
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
@@ -51,14 +48,23 @@ public partial class RarArchive
         }
     }
 
+    public override async ValueTask DisposeAsync()
+    {
+        if (!_disposed)
+        {
+            if (UnpackV1.IsValueCreated && UnpackV1.Value is IDisposable unpackV1)
+            {
+                unpackV1.Dispose();
+            }
+
+            _disposed = true;
+            await base.DisposeAsync();
+        }
+    }
+
     protected override IEnumerable<RarArchiveEntry> LoadEntries(IEnumerable<RarVolume> volumes) =>
         RarArchiveEntryFactory.GetEntries(this, volumes, ReaderOptions);
 
-    // Simple async property - kept in original file
-    protected override IAsyncEnumerable<RarArchiveEntry> LoadEntriesAsync(
-        IAsyncEnumerable<RarVolume> volumes
-    ) => RarArchiveEntryFactory.GetEntriesAsync(this, volumes, ReaderOptions);
-
     protected override IEnumerable<RarVolume> LoadVolumes(SourceStream sourceStream)
     {
         sourceStream.LoadAllParts();
@@ -80,7 +86,13 @@ public partial class RarArchive
         return new StreamRarArchiveVolume(sourceStream, ReaderOptions, i++).AsEnumerable();
     }
 
-    protected override IReader CreateReaderForSolidExtraction()
+    protected override IReader CreateReaderForSolidExtraction() =>
+        CreateReaderForSolidExtractionInternal();
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
+        new(CreateReaderForSolidExtractionInternal());
+
+    private RarReader CreateReaderForSolidExtractionInternal()
     {
         if (this.IsMultipartVolume())
         {
@@ -102,6 +114,5 @@ public partial class RarArchive
     public override bool IsEncrypted => Entries.First(x => !x.IsDirectory).IsEncrypted;
 
     public virtual int MinVersion => Volumes.First().MinVersion;
-
     public virtual int MaxVersion => Volumes.First().MaxVersion;
 }

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

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

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

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

src/SharpCompress/Archives/Rar/RarArchiveEntryFactory.cs

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

src/SharpCompress/Archives/Rar/RarArchiveVolumeFactory.cs

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

src/SharpCompress/Archives/Rar/SeekableFilePart.cs

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

src/SharpCompress/Archives/Rar/StreamRarArchiveVolume.cs

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

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

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

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

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

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -16,65 +16,48 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
 {
     private ArchiveDatabase? _database;
 
-    /// <summary>
-    /// Constructor with a SourceStream able to handle FileInfo and Streams.
-    /// </summary>
-    /// <param name="sourceStream"></param>
     private SevenZipArchive(SourceStream sourceStream)
         : base(ArchiveType.SevenZip, sourceStream) { }
 
-    protected override IEnumerable<SevenZipVolume> LoadVolumes(SourceStream sourceStream)
-    {
-        sourceStream.NotNull("SourceStream is null").LoadAllParts(); //request all streams
-        return new SevenZipVolume(sourceStream, ReaderOptions, 0).AsEnumerable(); //simple single volume or split, multivolume not supported
-    }
-
     internal SevenZipArchive()
         : base(ArchiveType.SevenZip) { }
 
+    protected override IEnumerable<SevenZipVolume> LoadVolumes(SourceStream sourceStream)
+    {
+        sourceStream.NotNull("SourceStream is null").LoadAllParts();
+        return new SevenZipVolume(sourceStream, ReaderOptions, 0).AsEnumerable();
+    }
+
     protected override IEnumerable<SevenZipArchiveEntry> LoadEntries(
         IEnumerable<SevenZipVolume> volumes
     )
     {
-        foreach (var volume in volumes)
+        var stream = volumes.Single().Stream;
+        LoadFactory(stream);
+        if (_database is null)
         {
-            LoadFactory(volume.Stream);
-            if (_database is null)
+            return Enumerable.Empty<SevenZipArchiveEntry>();
+        }
+        var entries = new SevenZipArchiveEntry[_database._files.Count];
+        for (var i = 0; i < _database._files.Count; i++)
+        {
+            var file = _database._files[i];
+            entries[i] = new SevenZipArchiveEntry(
+                this,
+                new SevenZipFilePart(stream, _database, i, file, ReaderOptions.ArchiveEncoding)
+            );
+        }
+        foreach (var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder))
+        {
+            var isSolid = false;
+            foreach (var entry in group)
             {
-                yield break;
-            }
-            var entries = new SevenZipArchiveEntry[_database._files.Count];
-            for (var i = 0; i < _database._files.Count; i++)
-            {
-                var file = _database._files[i];
-                entries[i] = new SevenZipArchiveEntry(
-                    this,
-                    new SevenZipFilePart(
-                        volume.Stream,
-                        _database,
-                        i,
-                        file,
-                        ReaderOptions.ArchiveEncoding
-                    )
-                );
-            }
-            foreach (
-                var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder)
-            )
-            {
-                var isSolid = false;
-                foreach (var entry in group)
-                {
-                    entry.IsSolid = isSolid;
-                    isSolid = true;
-                }
-            }
-
-            foreach (var entry in entries)
-            {
-                yield return entry;
+                entry.IsSolid = isSolid;
+                isSolid = true;
             }
         }
+
+        return entries;
     }
 
     private void LoadFactory(Stream stream)
@@ -91,6 +74,9 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
     protected override IReader CreateReaderForSolidExtraction() =>
         new SevenZipReader(ReaderOptions, this);
 
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync() =>
+        new(new SevenZipReader(ReaderOptions, this));
+
     public override bool IsSolid =>
         Entries
             .Where(x => !x.IsDirectory)
@@ -102,34 +88,13 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
     public override long TotalSize =>
         _database?._packSizes.Aggregate(0L, (total, packSize) => total + packSize) ?? 0;
 
-    internal sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
+    private sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
     {
         private readonly SevenZipArchive _archive;
         private SevenZipEntry? _currentEntry;
-        private Stream? _currentFolderStream;
-        private CFolder? _currentFolder;
-
-        /// <summary>
-        /// Enables internal diagnostics for tests.
-        /// When disabled (default), diagnostics properties return null to avoid exposing internal state.
-        /// </summary>
-        internal bool DiagnosticsEnabled { get; set; }
-
-        /// <summary>
-        /// Current folder instance used to decide whether the solid folder stream should be reused.
-        /// Only available when <see cref="DiagnosticsEnabled"/> is true.
-        /// </summary>
-        internal object? DiagnosticsCurrentFolder => DiagnosticsEnabled ? _currentFolder : null;
-
-        /// <summary>
-        /// Current shared folder stream instance.
-        /// Only available when <see cref="DiagnosticsEnabled"/> is true.
-        /// </summary>
-        internal Stream? DiagnosticsCurrentFolderStream =>
-            DiagnosticsEnabled ? _currentFolderStream : null;
 
         internal SevenZipReader(ReaderOptions readerOptions, SevenZipArchive archive)
-            : base(readerOptions, ArchiveType.SevenZip, false) => this._archive = archive;
+            : base(readerOptions, ArchiveType.SevenZip) => this._archive = archive;
 
         public override SevenZipVolume Volume => _archive.Volumes.Single();
 
@@ -142,10 +107,6 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
                 _currentEntry = dir;
                 yield return dir;
             }
-            // For solid archives (entries in the same folder share a compressed stream),
-            // we must iterate entries sequentially and maintain the folder stream state
-            // across entries in the same folder to avoid recreating the decompression
-            // stream for each file, which breaks contiguous streaming.
             foreach (var entry in entries.Where(x => !x.IsDirectory))
             {
                 _currentEntry = entry;
@@ -160,53 +121,10 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
             {
                 return CreateEntryStream(Stream.Null);
             }
-
-            var folder = entry.FilePart.Folder;
-
-            // Check if we're starting a new folder - dispose old folder stream if needed
-            if (folder != _currentFolder)
-            {
-                _currentFolderStream?.Dispose();
-                _currentFolderStream = null;
-                _currentFolder = folder;
-            }
-
-            // Create the folder stream once per folder
-            if (_currentFolderStream is null)
-            {
-                _currentFolderStream = _archive._database!.GetFolderStream(
-                    _archive.Volumes.Single().Stream,
-                    folder!,
-                    _archive._database.PasswordProvider
-                );
-            }
-
-            // Wrap with SyncOnlyStream to work around LZMA async bugs
-            // Return a ReadOnlySubStream that reads from the shared folder stream
-            return CreateEntryStream(
-                new SyncOnlyStream(
-                    new ReadOnlySubStream(_currentFolderStream, entry.Size, leaveOpen: true)
-                )
-            );
-        }
-
-        public override void Dispose()
-        {
-            _currentFolderStream?.Dispose();
-            _currentFolderStream = null;
-            base.Dispose();
+            return CreateEntryStream(new SyncOnlyStream(entry.FilePart.GetCompressedStream()));
         }
     }
 
-    /// <summary>
-    /// WORKAROUND: Forces async operations to use synchronous equivalents.
-    /// This is necessary because the LZMA decoder has bugs in its async implementation
-    /// that cause state corruption (IndexOutOfRangeException, DataErrorException).
-    ///
-    /// The proper fix would be to repair the LZMA decoder's async methods
-    /// (LzmaStream.ReadAsync, Decoder.CodeAsync, OutWindow async operations),
-    /// but that requires deep changes to the decoder state machine.
-    /// </summary>
     private sealed class SyncOnlyStream : Stream
     {
         private readonly Stream _baseStream;
@@ -236,7 +154,6 @@ public partial class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, Sev
         public override void Write(byte[] buffer, int offset, int count) =>
             _baseStream.Write(buffer, offset, count);
 
-        // Force async operations to use sync equivalents to avoid LZMA decoder bugs
         public override Task<int> ReadAsync(
             byte[] buffer,
             int offset,

src/SharpCompress/Archives/SevenZip/SevenZipArchiveEntry.cs

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

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

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

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

@@ -2,13 +2,15 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using SharpCompress.Common;
+using SharpCompress.Common.Tar;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.IO;
 using SharpCompress.Readers;
+using SharpCompress.Writers;
+using SharpCompress.Writers.Tar;
 
 namespace SharpCompress.Archives.Tar;
 
@@ -21,7 +23,7 @@ public partial class TarArchive
     public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
+        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
     public static IWritableArchive OpenArchive(
@@ -34,7 +36,7 @@ public partial class TarArchive
             new SourceStream(
                 fileInfo,
                 i => ArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -50,7 +52,7 @@ public partial class TarArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -152,48 +154,15 @@ public partial class TarArchive
         try
         {
             var tarHeader = new TarHeader(new ArchiveEncoding());
-            var reader = new BinaryReader(stream, Encoding.UTF8, false);
-            var readSucceeded = tarHeader.Read(reader);
+            var readSucceeded = tarHeader.Read(new BinaryReader(stream));
             var isEmptyArchive =
                 tarHeader.Name?.Length == 0
                 && tarHeader.Size == 0
                 && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
             return readSucceeded || isEmptyArchive;
         }
-        catch (Exception)
-        {
-            // Catch all exceptions during tar header reading to determine if this is a valid tar file
-            // Invalid tar files or corrupted streams will throw various exceptions
-            return false;
-        }
-    }
-
-    public static async ValueTask<bool> IsTarFileAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        try
-        {
-            var tarHeader = new TarHeader(new ArchiveEncoding());
-#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;
-        }
+        catch { }
+        return false;
     }
 
     public static IWritableArchive CreateArchive() => new TarArchive();

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -32,10 +32,6 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
     protected override IEnumerable<TarArchiveEntry> LoadEntries(IEnumerable<TarVolume> volumes)
     {
         var stream = volumes.Single().Stream;
-        if (stream.CanSeek)
-        {
-            stream.Position = 0;
-        }
         TarHeader? previousHeader = null;
         foreach (
             var header in TarHeaderFactory.ReadHeader(
@@ -66,7 +62,7 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
                         using (var entryStream = entry.OpenEntryStream())
                         {
                             using var memoryStream = new MemoryStream();
-                            entryStream.CopyTo(memoryStream, Constants.BufferSize);
+                            entryStream.CopyTo(memoryStream);
                             memoryStream.Position = 0;
                             var bytes = memoryStream.ToArray();
 
@@ -143,10 +139,54 @@ public partial class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVo
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<TarArchiveEntry> oldEntries,
+        IEnumerable<TarArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var writer = new TarWriter(stream, new TarWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries))
+        {
+            if (entry.IsDirectory)
+            {
+                await writer
+                    .WriteDirectoryAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entry.LastModifiedTime,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                await writer
+                    .WriteAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entryStream,
+                        entry.LastModifiedTime,
+                        entry.Size,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+        }
+    }
+
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
         stream.Position = 0;
         return TarReader.OpenReader(stream);
     }
+
+    protected override ValueTask<IAsyncReader> CreateReaderForSolidExtractionAsync()
+    {
+        var stream = Volumes.Single().Stream;
+        stream.Position = 0;
+        return new((IAsyncReader)TarReader.OpenReader(stream));
+    }
 }

src/SharpCompress/Archives/Tar/TarArchiveEntry.cs

@@ -14,9 +14,8 @@ public class TarArchiveEntry : TarEntry, IArchiveEntry
 
     public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream().NotNull();
 
-    public async ValueTask<Stream> OpenEntryStreamAsync(
-        CancellationToken cancellationToken = default
-    ) => (await Parts.Single().GetCompressedStreamAsync(cancellationToken)).NotNull();
+    public ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default) =>
+        new(OpenEntryStream());
 
     #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.CreateNonDisposing(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()

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

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

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

@@ -21,7 +21,7 @@ public partial class ZipArchive
     public static IWritableArchive OpenArchive(string filePath, ReaderOptions? readerOptions = null)
     {
         filePath.NotNullOrEmpty(nameof(filePath));
-        return OpenArchive(new FileInfo(filePath), readerOptions);
+        return OpenArchive(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
     public static IWritableArchive OpenArchive(
@@ -34,7 +34,7 @@ public partial class ZipArchive
             new SourceStream(
                 fileInfo,
                 i => ZipArchiveVolumeFactory.GetFilePart(i, fileInfo),
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -50,7 +50,7 @@ public partial class ZipArchive
             new SourceStream(
                 files[0],
                 i => i < files.Length ? files[i] : null,
-                readerOptions ?? new ReaderOptions() { LeaveStreamOpen = false }
+                readerOptions ?? new ReaderOptions()
             )
         );
     }
@@ -135,24 +135,40 @@ public partial class ZipArchive
         return (IWritableAsyncArchive)OpenArchive(fileInfos, readerOptions);
     }
 
-    public static bool IsZipFile(string filePath, string? password = null) =>
-        IsZipFile(new FileInfo(filePath), password);
+    public static bool IsZipFile(
+        string filePath,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    ) => IsZipFile(new FileInfo(filePath), password, bufferSize);
 
-    public static bool IsZipFile(FileInfo fileInfo, string? password = null)
+    public static bool IsZipFile(
+        FileInfo fileInfo,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         if (!fileInfo.Exists)
         {
             return false;
         }
         using Stream stream = fileInfo.OpenRead();
-        return IsZipFile(stream, password);
+        return IsZipFile(stream, password, bufferSize);
     }
 
-    public static bool IsZipFile(Stream stream, string? password = null)
+    public static bool IsZipFile(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
         try
         {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
             var header = headerFactory
                 .ReadStreamHeader(stream)
                 .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
@@ -172,11 +188,20 @@ public partial class ZipArchive
         }
     }
 
-    public static bool IsZipMulti(Stream stream, string? password = null)
+    public static bool IsZipMulti(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
         try
         {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
             var header = headerFactory
                 .ReadStreamHeader(stream)
                 .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
@@ -185,7 +210,7 @@ public partial class ZipArchive
                 if (stream.CanSeek)
                 {
                     var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    var x = z.ReadSeekableHeader(stream).FirstOrDefault();
+                    var x = z.ReadSeekableHeader(stream, useSync: true).FirstOrDefault();
                     return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
                 }
                 else
@@ -208,6 +233,7 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipFileAsync(
         Stream stream,
         string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -215,6 +241,11 @@ 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)
@@ -242,6 +273,7 @@ public partial class ZipArchive
     public static async ValueTask<bool> IsZipMultiAsync(
         Stream stream,
         string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
         CancellationToken cancellationToken = default
     )
     {
@@ -249,6 +281,11 @@ 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

@@ -35,18 +35,15 @@ 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)
         {
-            //check if second stream is zip header without changing position
-            var headerProbeStream = streams[1];
-            var startPosition = headerProbeStream.Position;
-            headerProbeStream.Position = startPosition + 4;
-            var isZip = IsZipFile(headerProbeStream, ReaderOptions.Password);
-            headerProbeStream.Position = startPosition;
+            streams[1].Position += 4;
+            var isZip = IsZipFile(streams[1], ReaderOptions.Password, ReaderOptions.BufferSize);
+            streams[1].Position -= 4;
             if (isZip)
             {
                 stream.IsVolumes = true;
@@ -65,7 +62,9 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
     protected override IEnumerable<ZipArchiveEntry> LoadEntries(IEnumerable<ZipVolume> volumes)
     {
         var vols = volumes.ToArray();
-        foreach (var h in headerFactory.NotNull().ReadSeekableHeader(vols.Last().Stream))
+        foreach (
+            var h in headerFactory.NotNull().ReadSeekableHeader(vols.Last().Stream, useSync: true)
+        )
         {
             if (h != null)
             {
@@ -109,6 +108,59 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         }
     }
 
+    protected override async IAsyncEnumerable<ZipArchiveEntry> LoadEntriesAsync(
+        IAsyncEnumerable<ZipVolume> volumes
+    )
+    {
+        var vols = await volumes.ToListAsync();
+        var volsArray = vols.ToArray();
+
+        await foreach (
+            var h in headerFactory.NotNull().ReadSeekableHeaderAsync(volsArray.Last().Stream)
+        )
+        {
+            if (h != null)
+            {
+                switch (h.ZipHeaderType)
+                {
+                    case ZipHeaderType.DirectoryEntry:
+                        {
+                            var deh = (DirectoryEntryHeader)h;
+                            Stream s;
+                            if (
+                                deh.RelativeOffsetOfEntryHeader + deh.CompressedSize
+                                > volsArray[deh.DiskNumberStart].Stream.Length
+                            )
+                            {
+                                var v = volsArray.Skip(deh.DiskNumberStart).ToArray();
+                                s = new SourceStream(
+                                    v[0].Stream,
+                                    i => i < v.Length ? v[i].Stream : null,
+                                    new ReaderOptions() { LeaveStreamOpen = true }
+                                );
+                            }
+                            else
+                            {
+                                s = volsArray[deh.DiskNumberStart].Stream;
+                            }
+
+                            yield return new ZipArchiveEntry(
+                                this,
+                                new SeekableZipFilePart(headerFactory.NotNull(), deh, s)
+                            );
+                        }
+                        break;
+                    case ZipHeaderType.DirectoryEnd:
+                    {
+                        var bytes = ((DirectoryEndHeader)h).Comment ?? Array.Empty<byte>();
+                        volsArray.Last().Comment = ReaderOptions.ArchiveEncoding.Decode(bytes);
+                        yield break;
+                    }
+                }
+            }
+        }
+    }
+
     public void SaveTo(Stream stream) => SaveTo(stream, new WriterOptions(CompressionType.Deflate));
 
     protected override void SaveTo(
@@ -140,6 +192,41 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
         }
     }
 
+    protected override async ValueTask SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<ZipArchiveEntry> oldEntries,
+        IEnumerable<ZipArchiveEntry> newEntries,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var writer = new ZipWriter(stream, new ZipWriterOptions(options));
+        foreach (var entry in oldEntries.Concat(newEntries))
+        {
+            if (entry.IsDirectory)
+            {
+                await writer
+                    .WriteDirectoryAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entry.LastModifiedTime,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                await writer
+                    .WriteAsync(
+                        entry.Key.NotNull("Entry Key is null"),
+                        entryStream,
+                        cancellationToken
+                    )
+                    .ConfigureAwait(false);
+            }
+        }
+    }
+
     protected override ZipArchiveEntry CreateEntryInternal(
         string filePath,
         Stream source,
@@ -156,7 +243,7 @@ public partial class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVo
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
-        //stream.Position = 0;
+        ((IStreamStack)stream).StackSeek(0);
         return ZipReader.OpenReader(stream, ReaderOptions, Entries);
     }
 

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

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

src/SharpCompress/Archives/Zip/ZipArchiveEntry.cs

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

src/SharpCompress/Archives/Zip/ZipArchiveVolumeFactory.cs

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

src/SharpCompress/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.CreateNonDisposing(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()

src/SharpCompress/Common/Ace/AceCrc.cs

@@ -4,61 +4,58 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Ace;
-
-public class AceCrc
+namespace SharpCompress.Common.Ace
 {
-    // CRC-32 lookup table (standard polynomial 0xEDB88320, reflected)
-    private static readonly uint[] Crc32Table = GenerateTable();
-
-    private static uint[] GenerateTable()
+    public class AceCrc
     {
-        var table = new uint[256];
+        // CRC-32 lookup table (standard polynomial 0xEDB88320, reflected)
+        private static readonly uint[] Crc32Table = GenerateTable();
 
-        for (int i = 0; i < 256; i++)
+        private static uint[] GenerateTable()
         {
-            uint crc = (uint)i;
+            var table = new uint[256];
 
-            for (int j = 0; j < 8; j++)
+            for (int i = 0; i < 256; i++)
             {
-                if ((crc & 1) != 0)
+                uint crc = (uint)i;
+
+                for (int j = 0; j < 8; j++)
                 {
-                    crc = (crc >> 1) ^ 0xEDB88320u;
-                }
-                else
-                {
-                    crc >>= 1;
+                    if ((crc & 1) != 0)
+                        crc = (crc >> 1) ^ 0xEDB88320u;
+                    else
+                        crc >>= 1;
                 }
+
+                table[i] = crc;
             }
 
-            table[i] = crc;
+            return table;
         }
 
-        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)
+        /// <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)
         {
-            crc = (crc >> 8) ^ Crc32Table[(crc ^ b) & 0xFF];
+            uint crc = 0xFFFFFFFFu;
+
+            foreach (byte b in data)
+            {
+                crc = (crc >> 8) ^ Crc32Table[(crc ^ b) & 0xFF];
+            }
+
+            return crc; // No final XOR for ACE
         }
 
-        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);
+        /// <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

@@ -6,62 +6,63 @@ using System.Text;
 using System.Threading.Tasks;
 using SharpCompress.Common.Ace.Headers;
 
-namespace SharpCompress.Common.Ace;
-
-public class AceEntry : Entry
+namespace SharpCompress.Common.Ace
 {
-    private readonly AceFilePart _filePart;
-
-    internal AceEntry(AceFilePart filePart)
+    public class AceEntry : Entry
     {
-        _filePart = filePart;
-    }
+        private readonly AceFilePart _filePart;
 
-    public override long Crc
-    {
-        get
+        internal AceEntry(AceFilePart filePart)
         {
-            if (_filePart == null)
-            {
-                return 0;
-            }
-            return _filePart.Header.Crc32;
+            _filePart = filePart;
         }
-    }
 
-    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
+        public override long Crc
         {
-            if (_filePart.Header.CompressionType == Headers.CompressionType.Stored)
+            get
             {
-                return CompressionType.None;
+                if (_filePart == null)
+                {
+                    return 0;
+                }
+                return _filePart.Header.Crc32;
             }
-            return CompressionType.AceLZ77;
         }
+
+        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();
     }
-
-    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

@@ -7,45 +7,46 @@ using System.Threading.Tasks;
 using SharpCompress.Common.Ace.Headers;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Ace;
-
-public class AceFilePart : FilePart
+namespace SharpCompress.Common.Ace
 {
-    private readonly Stream _stream;
-    internal AceFileHeader Header { get; set; }
-
-    internal AceFilePart(AceFileHeader localAceHeader, Stream seekableStream)
-        : base(localAceHeader.ArchiveEncoding)
+    public class AceFilePart : FilePart
     {
-        _stream = seekableStream;
-        Header = localAceHeader;
-    }
+        private readonly Stream _stream;
+        internal AceFileHeader Header { get; set; }
 
-    internal override string? FilePartName => Header.Filename;
-
-    internal override Stream GetCompressedStream()
-    {
-        if (_stream != null)
+        internal AceFilePart(AceFileHeader localAceHeader, Stream seekableStream)
+            : base(localAceHeader.ArchiveEncoding)
         {
-            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;
+            _stream = seekableStream;
+            Header = localAceHeader;
         }
-        return _stream.NotNull();
-    }
 
-    internal override Stream? GetRawStream() => _stream;
+        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

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

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

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

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

@@ -2,173 +2,170 @@ 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;
-
-/// <summary>
-/// ACE file entry header
-/// </summary>
-public sealed partial class AceFileHeader : AceHeader
+namespace SharpCompress.Common.Ace.Headers
 {
-    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
+    /// ACE file entry header
     /// </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
+    public sealed class AceFileHeader : AceHeader
     {
-        get
+        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
         {
-            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)
+            get
             {
-                ushort commentLength = BitConverter.ToUInt16(headerData, offset);
-                offset += 2 + commentLength; // Skip comment
+                int bits = Parameters & 0x0F;
+                return bits < 10 ? 1024 : 1 << bits;
             }
         }
 
-        // Store the data start position
-        DataStartPosition = stream.Position;
+        public AceFileHeader(IArchiveEncoding archiveEncoding)
+            : base(archiveEncoding, AceHeaderType.FILE) { }
 
-        return this;
+        /// <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,
+            };
     }
-
-    // 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

@@ -1,69 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace SharpCompress.Common.Ace.Headers;
-
-public abstract partial class AceHeader
-{
-    public abstract ValueTask<AceHeader?> ReadAsync(
-        Stream reader,
-        CancellationToken cancellationToken = default
-    );
-
-    public async ValueTask<byte[]> ReadHeaderAsync(
-        Stream stream,
-        CancellationToken cancellationToken = default
-    )
-    {
-        // Read header CRC (2 bytes) and header size (2 bytes)
-        var headerBytes = new byte[4];
-        if (!await stream.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

@@ -1,156 +1,153 @@
 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;
-
-/// <summary>
-/// Header type constants
-/// </summary>
-public enum AceHeaderType
+namespace SharpCompress.Common.Ace.Headers
 {
-    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)
+    /// <summary>
+    /// Header type constants
+    /// </summary>
+    public enum AceHeaderType
     {
-        AceHeaderType = type;
-        ArchiveEncoding = archiveEncoding;
+        MAIN = 0,
+        FILE = 1,
+        RECOVERY32 = 2,
+        RECOVERY64A = 3,
+        RECOVERY64B = 4,
     }
 
-    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)
+    public abstract class AceHeader
     {
-        // Read header CRC (2 bytes) and header size (2 bytes)
-        var headerBytes = new byte[4];
-        if (!stream.ReadFully(headerBytes))
+        // 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)
         {
-            return Array.Empty<byte>();
+            AceHeaderType = type;
+            ArchiveEncoding = archiveEncoding;
         }
 
-        HeaderCrc = BitConverter.ToUInt16(headerBytes, 0); // CRC for validation
-        HeaderSize = BitConverter.ToUInt16(headerBytes, 2);
-        if (HeaderSize == 0)
+        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)
         {
-            return Array.Empty<byte>();
+            // 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;
         }
 
-        // Read the header data
-        var body = new byte[HeaderSize];
-        if (!stream.ReadFully(body))
+        public static bool IsArchive(Stream stream)
         {
-            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])
+            // 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);
         }
-        return true;
-    }
 
-    protected DateTime ConvertDosDateTime(uint dosDateTime)
-    {
-        try
+        protected static bool CheckMagicBytes(byte[] headerBytes, int offset)
         {
-            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;
+            // Check for "**ACE**" at specified offset
+            for (int i = 0; i < AceSignature.Length; i++)
+            {
+                if (headerBytes[offset + i] != AceSignature[i])
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
 
-            if (
-                day < 1
-                || day > 31
-                || month < 1
-                || month > 12
-                || hour > 23
-                || minute > 59
-                || second > 59
-            )
+        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
             {
                 return DateTime.MinValue;
             }
-
-            return new DateTime(year, month, day, hour, minute, second);
-        }
-        catch
-        {
-            return DateTime.MinValue;
         }
     }
 }

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

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

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

@@ -2,99 +2,96 @@ 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;
-
-/// <summary>
-/// ACE main archive header
-/// </summary>
-public sealed partial class AceMainHeader : AceHeader
+namespace SharpCompress.Common.Ace.Headers
 {
-    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.
+    /// ACE main archive header
     /// </summary>
-    public override AceHeader? Read(Stream stream)
+    public sealed class AceMainHeader : AceHeader
     {
-        var headerData = ReadHeader(stream);
-        if (headerData.Length == 0)
+        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)
         {
-            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)
+            var headerData = ReadHeader(stream);
+            if (headerData.Length == 0)
             {
-                ushort commentLength = BitConverter.ToUInt16(headerData, offset);
-                offset += 2 + commentLength;
+                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 this;
     }
-
-    // ReadAsync moved to AceMainHeader.Async.cs
 }

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

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

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

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

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

@@ -1,32 +1,33 @@
-namespace SharpCompress.Common.Ace.Headers;
-
-/// <summary>
-/// Header flags (main + file, overlapping meanings)
-/// </summary>
-public static class HeaderFlags
+namespace SharpCompress.Common.Ace.Headers
 {
-    // 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;
+    /// <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;
 
-    // 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

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

src/SharpCompress/Common/Arc/ArcEntry.cs

@@ -7,53 +7,54 @@ using System.Threading.Tasks;
 using SharpCompress.Common.GZip;
 using SharpCompress.Common.Tar;
 
-namespace SharpCompress.Common.Arc;
-
-public class ArcEntry : Entry
+namespace SharpCompress.Common.Arc
 {
-    private readonly ArcFilePart? _filePart;
-
-    internal ArcEntry(ArcFilePart? filePart)
+    public class ArcEntry : Entry
     {
-        _filePart = filePart;
-    }
+        private readonly ArcFilePart? _filePart;
 
-    public override long Crc
-    {
-        get
+        internal ArcEntry(ArcFilePart? filePart)
         {
-            if (_filePart == null)
-            {
-                return 0;
-            }
-            return _filePart.Header.Crc16;
+            _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();
     }
-
-    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

@@ -2,93 +2,75 @@ using System;
 using System.IO;
 using System.Linq;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Arc;
-
-public class ArcEntryHeader
+namespace SharpCompress.Common.Arc
 {
-    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 class ArcEntryHeader
     {
-        this.ArchiveEncoding = 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; }
 
-    public ArcEntryHeader? ReadHeader(Stream stream)
-    {
-        byte[] headerBytes = new byte[29];
-        if (stream.Read(headerBytes, 0, headerBytes.Length) != headerBytes.Length)
+        public ArcEntryHeader(IArchiveEncoding archiveEncoding)
         {
-            return null;
+            this.ArchiveEncoding = archiveEncoding;
         }
-        DataStartPosition = stream.Position;
-        return LoadFrom(headerBytes);
-    }
 
-    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
-        )
+        public ArcEntryHeader? ReadHeader(Stream stream)
         {
-            return null;
+            byte[] headerBytes = new byte[29];
+            if (stream.Read(headerBytes, 0, headerBytes.Length) != headerBytes.Length)
+            {
+                return null;
+            }
+            DataStartPosition = stream.Position;
+            return LoadFrom(headerBytes);
         }
-        DataStartPosition = stream.Position;
-        return LoadFrom(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
+        public ArcEntryHeader LoadFrom(byte[] headerBytes)
         {
-            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,
-        };
-    }
+            CompressionMethod = GetCompressionType(headerBytes[1]);
 
-    public static DateTime ConvertToDateTime(long rawDateTime)
-    {
-        // Convert Unix timestamp to DateTime (UTC)
-        return DateTimeOffset.FromUnixTimeSeconds(rawDateTime).UtcDateTime;
+            // 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;
+        }
     }
 }

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

@@ -1,58 +0,0 @@
-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

@@ -13,61 +13,71 @@ using SharpCompress.Compressors.RLE90;
 using SharpCompress.Compressors.Squeezed;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Arc;
-
-public partial class ArcFilePart : FilePart
+namespace SharpCompress.Common.Arc
 {
-    private readonly Stream? _stream;
-
-    internal ArcFilePart(ArcEntryHeader localArcHeader, Stream? seekableStream)
-        : base(localArcHeader.ArchiveEncoding)
+    public class ArcFilePart : FilePart
     {
-        _stream = seekableStream;
-        Header = localArcHeader;
-    }
+        private readonly Stream? _stream;
 
-    internal ArcEntryHeader Header { get; set; }
-
-    internal override string? FilePartName => Header.Name;
-
-    internal override Stream GetCompressedStream()
-    {
-        if (_stream != null)
+        internal ArcFilePart(ArcEntryHeader localArcHeader, Stream? seekableStream)
+            : base(localArcHeader.ArchiveEncoding)
         {
-            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;
+            _stream = seekableStream;
+            Header = localArcHeader;
         }
-        return _stream.NotNull();
-    }
 
-    internal override Stream? GetRawStream() => _stream;
+        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;
+    }
 }

src/SharpCompress/Common/Arc/ArcVolume.cs

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

src/SharpCompress/Common/Arj/ArjEntry.cs

@@ -6,52 +6,53 @@ using System.Threading.Tasks;
 using SharpCompress.Common.Arc;
 using SharpCompress.Common.Arj.Headers;
 
-namespace SharpCompress.Common.Arj;
-
-public class ArjEntry : Entry
+namespace SharpCompress.Common.Arj
 {
-    private readonly ArjFilePart _filePart;
-
-    internal ArjEntry(ArjFilePart filePart)
+    public class ArjEntry : Entry
     {
-        _filePart = filePart;
-    }
+        private readonly ArjFilePart _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
+        internal ArjEntry(ArjFilePart filePart)
         {
-            if (_filePart.Header.CompressionMethod == CompressionMethod.Stored)
-            {
-                return CompressionType.None;
-            }
-            return CompressionType.ArjLZ77;
+            _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();
     }
-
-    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

@@ -8,62 +8,65 @@ using SharpCompress.Common.Arj.Headers;
 using SharpCompress.Compressors.Arj;
 using SharpCompress.IO;
 
-namespace SharpCompress.Common.Arj;
-
-public class ArjFilePart : FilePart
+namespace SharpCompress.Common.Arj
 {
-    private readonly Stream _stream;
-    internal ArjLocalHeader Header { get; set; }
-
-    internal ArjFilePart(ArjLocalHeader localArjHeader, Stream seekableStream)
-        : base(localArjHeader.ArchiveEncoding)
+    public class ArjFilePart : FilePart
     {
-        _stream = seekableStream;
-        Header = localArjHeader;
-    }
+        private readonly Stream _stream;
+        internal ArjLocalHeader Header { get; set; }
 
-    internal override string? FilePartName => Header.Name;
-
-    internal override Stream GetCompressedStream()
-    {
-        if (_stream != null)
+        internal ArjFilePart(ArjLocalHeader localArjHeader, Stream seekableStream)
+            : base(localArjHeader.ArchiveEncoding)
         {
-            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;
+            _stream = seekableStream;
+            Header = localArjHeader;
         }
-        return _stream.NotNull();
-    }
 
-    internal override Stream GetRawStream() => _stream;
+        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

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

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

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

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

@@ -3,158 +3,156 @@ 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;
-
-public enum ArjHeaderType
+namespace SharpCompress.Common.Arj.Headers
 {
-    MainHeader,
-    LocalHeader,
-}
-
-public abstract partial class ArjHeader
-{
-    private const int FIRST_HDR_SIZE = 34;
-    private const ushort ARJ_MAGIC = 0xEA60;
-
-    public ArjHeader(ArjHeaderType type)
+    public enum ArjHeaderType
     {
-        ArjHeaderType = type;
+        MainHeader,
+        LocalHeader,
     }
 
-    public ArjHeaderType ArjHeaderType { get; }
-    public byte Flags { get; set; }
-    public FileType FileType { get; set; }
-
-    public abstract ArjHeader? Read(Stream reader);
-
-    // Async methods moved to ArjHeader.Async.cs
-
-    public byte[] ReadHeader(Stream stream)
+    public abstract class ArjHeader
     {
-        // check for magic bytes
-        var magic = new byte[2];
-        if (stream.Read(magic) != 2)
+        private const int FIRST_HDR_SIZE = 34;
+        private const ushort ARJ_MAGIC = 0xEA60;
+
+        public ArjHeader(ArjHeaderType type)
         {
-            return Array.Empty<byte>();
+            ArjHeaderType = type;
         }
 
-        if (!CheckMagicBytes(magic))
+        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)
         {
-            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)
+            // check for magic bytes
+            var magic = new byte[2];
+            if (stream.Read(magic) != 2)
             {
-                throw new EndOfStreamException(
-                    "Unexpected end of stream while reading extended header size."
-                );
+                return Array.Empty<byte>();
             }
 
-            var extHeaderSize = (ushort)(buffer[0] | (buffer[1] << 8));
-            if (extHeaderSize == 0)
+            if (!CheckMagicBytes(magic))
             {
-                return extendedHeader;
+                throw new InvalidDataException("Not an ARJ file (wrong magic bytes)");
             }
 
-            byte[] header = new byte[extHeaderSize];
-            bytesRead = reader.Read(header, 0, extHeaderSize);
-            if (bytesRead < extHeaderSize)
+            // read header_size
+            byte[] headerBytes = new byte[2];
+            stream.Read(headerBytes, 0, 2);
+            var headerSize = (ushort)(headerBytes[0] | headerBytes[1] << 8);
+            if (headerSize < 1)
             {
-                throw new EndOfStreamException(
-                    "Unexpected end of stream while reading extended header data."
-                );
+                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];
-            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);
+            read = stream.Read(crc, 0, 4);
+            var checksum = Crc32Stream.Compute(body);
+            // Compute the hash value
             if (checksum != BitConverter.ToUInt32(crc, 0))
             {
-                throw new InvalidDataException("Extended header checksum is invalid");
+                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;
             }
 
-            extendedHeader.Add(header);
+            return CheckMagicBytes(bytes);
         }
-    }
 
-    // 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)
+        protected static bool CheckMagicBytes(byte[] headerBytes)
         {
-            return false;
+            var magicValue = (ushort)(headerBytes[0] | headerBytes[1] << 8);
+            return magicValue == ARJ_MAGIC;
         }
-
-        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

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

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

@@ -4,159 +4,158 @@ using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
 
-namespace SharpCompress.Common.Arj.Headers;
-
-public partial class ArjLocalHeader : ArjHeader
+namespace SharpCompress.Common.Arj.Headers
 {
-    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 class ArjLocalHeader : ArjHeader
     {
-        ArchiveEncoding =
-            archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
-    }
+        public ArchiveEncoding ArchiveEncoding { get; }
+        public long DataStartPosition { get; protected set; }
 
-    public override ArjHeader? Read(Stream stream)
-    {
-        var body = ReadHeader(stream);
-        if (body.Length > 0)
+        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)
         {
-            ReadExtendedHeaders(stream);
-            var header = LoadFrom(body);
-            header.DataStartPosition = stream.Position;
-            return header;
+            ArchiveEncoding =
+                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
         }
-        return null;
-    }
 
-    // ReadAsync moved to ArjLocalHeader.Async.cs
-
-    public ArjLocalHeader LoadFrom(byte[] headerBytes)
-    {
-        int offset = 0;
-
-        int ReadInt16()
+        public override ArjHeader? Read(Stream stream)
         {
-            if (offset + 1 >= headerBytes.Length)
+            var body = ReadHeader(stream);
+            if (body.Length > 0)
             {
-                throw new EndOfStreamException();
+                ReadExtendedHeaders(stream);
+                var header = LoadFrom(body);
+                header.DataStartPosition = stream.Position;
+                return header;
             }
-            var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
-            offset += 2;
-            return v;
+            return null;
         }
-        long ReadInt32()
+
+        public ArjLocalHeader LoadFrom(byte[] headerBytes)
         {
-            if (offset + 3 >= headerBytes.Length)
+            int offset = 0;
+
+            int ReadInt16()
             {
-                throw new EndOfStreamException();
+                if (offset + 1 >= headerBytes.Length)
+                {
+                    throw new EndOfStreamException();
+                }
+                var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
+                offset += 2;
+                return v;
             }
-            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)
+            long ReadInt32()
             {
-                rawTimestamp = ReadInt32();
-                DateTimeAccessed =
-                    rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
-                rawTimestamp = ReadInt32();
-                DateTimeCreated =
-                    rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
-                OriginalSizeEvenForVolumes = 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;
         }
 
-        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
+        public static CompressionMethod CompressionMethodFromByte(byte value)
         {
-            0 => CompressionMethod.Stored,
-            1 => CompressionMethod.CompressedMost,
-            2 => CompressionMethod.Compressed,
-            3 => CompressionMethod.CompressedFaster,
-            4 => CompressionMethod.CompressedFastest,
-            8 => CompressionMethod.NoDataNoCrc,
-            9 => CompressionMethod.NoData,
-            _ => CompressionMethod.Unknown,
-        };
+            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,
+            };
+        }
     }
 }

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

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

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

@@ -1,141 +1,138 @@
 using System;
 using System.IO;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.Crypto;
 
-namespace SharpCompress.Common.Arj.Headers;
-
-public partial class ArjMainHeader : ArjHeader
+namespace SharpCompress.Common.Arj.Headers
 {
-    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)
+    public class ArjMainHeader : ArjHeader
     {
-        ArchiveEncoding =
-            archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
-    }
+        private const int FIRST_HDR_SIZE = 34;
+        private const ushort ARJ_MAGIC = 0xEA60;
 
-    public override ArjHeader? Read(Stream stream)
-    {
-        var body = ReadHeader(stream);
-        ReadExtendedHeaders(stream);
-        return LoadFrom(body);
-    }
+        public ArchiveEncoding ArchiveEncoding { get; }
 
-    // ReadAsync moved to ArjMainHeader.Async.cs
+        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 ArjMainHeader LoadFrom(byte[] headerBytes)
-    {
-        var offset = 1;
+        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;
 
-        byte ReadByte()
+        public ArjMainHeader(ArchiveEncoding archiveEncoding)
+            : base(ArjHeaderType.MainHeader)
         {
-            if (offset >= headerBytes.Length)
-            {
-                throw new EndOfStreamException();
-            }
-            return (byte)(headerBytes[offset++] & 0xFF);
+            ArchiveEncoding =
+                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
         }
 
-        int ReadInt16()
+        public override ArjHeader? Read(Stream stream)
         {
-            if (offset + 1 >= headerBytes.Length)
-            {
-                throw new EndOfStreamException();
-            }
-            var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
-            offset += 2;
-            return v;
+            var body = ReadHeader(stream);
+            ReadExtendedHeaders(stream);
+            return LoadFrom(body);
         }
 
-        long ReadInt32()
+        public ArjMainHeader LoadFrom(byte[] headerBytes)
         {
-            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;
+            var offset = 1;
 
-            while (i < x.Length && x[i] != 0)
+            byte ReadByte()
             {
-                result.Append((char)x[i]);
+                if (offset >= headerBytes.Length)
+                {
+                    throw new EndOfStreamException();
+                }
+                return (byte)(headerBytes[offset++] & 0xFF);
+            }
+
+            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;
+            }
+            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
                 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();
             }
 
-            // 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;
-            }
+            ArchiverVersionNumber = ReadByte();
+            MinVersionToExtract = ReadByte();
 
-            return result.ToString();
+            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;
         }
-
-        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

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

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

@@ -1,36 +1,37 @@
 using System;
 
-namespace SharpCompress.Common.Arj.Headers;
-
-public class DosDateTime
+namespace SharpCompress.Common.Arj.Headers
 {
-    public DateTime DateTime { get; }
-
-    public DosDateTime(long dosValue)
+    public class DosDateTime
     {
-        // Ensure only the lower 32 bits are used
-        int value = unchecked((int)(dosValue & 0xFFFFFFFF));
+        public DateTime DateTime { get; }
 
-        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
+        public DosDateTime(long dosValue)
         {
-            DateTime = new DateTime(year, month, day, hour, minute, second);
-        }
-        catch
-        {
-            DateTime = DateTime.MinValue;
+            // 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;
+            }
         }
+
+        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

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

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

@@ -1,18 +1,19 @@
-namespace SharpCompress.Common.Arj.Headers;
-
-public enum HostOS
+namespace SharpCompress.Common.Arj.Headers
 {
-    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,
+    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,
+    }
 }

src/SharpCompress/Common/AsyncBinaryReader.cs

@@ -0,0 +1,103 @@
+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

@@ -1,41 +0,0 @@
-namespace SharpCompress.Common;
-
-public static class Constants
-{
-    /// <summary>
-    /// The default buffer size for stream operations, matching .NET's Stream.CopyTo default of 81920 bytes.
-    /// This can be modified globally at runtime.
-    /// </summary>
-    public static int BufferSize { get; set; } = 81920;
-
-    /// <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

@@ -1,81 +0,0 @@
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using SharpCompress.IO;
-
-namespace SharpCompress.Common;
-
-public partial class EntryStream
-{
-    /// <summary>
-    /// Asynchronously skip the rest of the entry stream.
-    /// </summary>
-    public async ValueTask SkipEntryAsync(CancellationToken cancellationToken = default)
-    {
-        await this.SkipAsync(cancellationToken).ConfigureAwait(false);
-        _completed = true;
-    }
-
-#if !LEGACY_DOTNET
-    public override async ValueTask DisposeAsync()
-    {
-        if (_isDisposed)
-        {
-            return;
-        }
-        _isDisposed = true;
-        if (!(_completed || _reader.Cancelled))
-        {
-            await SkipEntryAsync().ConfigureAwait(false);
-        }
-
-        //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised
-        if (_stream is IStreamStack ss)
-        {
-            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
-            {
-                await deflateStream.FlushAsync().ConfigureAwait(false);
-            }
-            else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
-            {
-                await lzmaStream.FlushAsync().ConfigureAwait(false);
-            }
-        }
-        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

@@ -8,8 +8,28 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Common;
 
-public partial class EntryStream : Stream
+public class EntryStream : Stream, IStreamStack
 {
+#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;
@@ -19,6 +39,9 @@ public partial class EntryStream : Stream
     {
         _reader = reader;
         _stream = stream;
+#if DEBUG_STREAMS
+        this.DebugConstruct(typeof(EntryStream));
+#endif
     }
 
     /// <summary>
@@ -30,6 +53,15 @@ public partial class EntryStream : Stream
         _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)
@@ -39,38 +71,61 @@ public partial class EntryStream : Stream
         _isDisposed = true;
         if (!(_completed || _reader.Cancelled))
         {
-            if (Utility.UseSyncOverAsyncDispose())
-            {
-                SkipEntryAsync().GetAwaiter().GetResult();
-            }
-            else
-            {
-                SkipEntry();
-            }
+            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.GetStream<SharpCompress.Compressors.Deflate.DeflateStream>()
-                is SharpCompress.Compressors.Deflate.DeflateStream deflateStream
-            )
+            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
             {
                 deflateStream.Flush(); //Deflate over reads. Knock it back
             }
-            else if (
-                ss.GetStream<SharpCompress.Compressors.LZMA.LzmaStream>()
-                is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream
-            )
+            else if (ss.BaseStream() 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;
@@ -99,6 +154,38 @@ public partial class EntryStream : Stream
         return read;
     }
 
+    public override async Task<int> ReadAsync(
+        byte[] buffer,
+        int offset,
+        int count,
+        CancellationToken cancellationToken
+    )
+    {
+        var read = await _stream
+            .ReadAsync(buffer, offset, count, cancellationToken)
+            .ConfigureAwait(false);
+        if (read <= 0)
+        {
+            _completed = true;
+        }
+        return read;
+    }
+
+#if !LEGACY_DOTNET
+    public override async ValueTask<int> ReadAsync(
+        Memory<byte> buffer,
+        CancellationToken cancellationToken = default
+    )
+    {
+        var read = await _stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
+        if (read <= 0)
+        {
+            _completed = true;
+        }
+        return read;
+    }
+#endif
+
     public override int ReadByte()
     {
         var value = _stream.ReadByte();

src/SharpCompress/Common/ExtractionMethods.Async.cs

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

src/SharpCompress/Common/ExtractionMethods.cs

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

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

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

src/SharpCompress/Common/GZip/GZipEntry.cs

@@ -4,7 +4,7 @@ using System.IO;
 
 namespace SharpCompress.Common.GZip;
 
-public partial class GZipEntry : Entry
+public class GZipEntry : Entry
 {
     private readonly GZipFilePart? _filePart;
 
@@ -42,6 +42,4 @@ public partial class GZipEntry : Entry
     {
         yield return new GZipEntry(GZipFilePart.Create(stream, options.ArchiveEncoding));
     }
-
-    // Async methods moved to GZipEntry.Async.cs
 }

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

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

src/SharpCompress/Common/GZip/GZipFilePart.cs

@@ -2,13 +2,15 @@ using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.Compressors;
 using SharpCompress.Compressors.Deflate;
 
 namespace SharpCompress.Common.GZip;
 
-internal sealed partial class GZipFilePart : FilePart
+internal sealed class GZipFilePart : FilePart
 {
     private string? _name;
     private readonly Stream _stream;
@@ -35,6 +37,32 @@ internal sealed partial class GZipFilePart : FilePart
         return part;
     }
 
+    internal static async ValueTask<GZipFilePart> CreateAsync(
+        Stream stream,
+        IArchiveEncoding archiveEncoding,
+        CancellationToken cancellationToken = default
+    )
+    {
+        var part = new GZipFilePart(stream, archiveEncoding);
+
+        await part.ReadAndValidateGzipHeaderAsync(cancellationToken);
+        if (stream.CanSeek)
+        {
+            var position = stream.Position;
+            stream.Position = stream.Length - 8;
+            await part.ReadTrailerAsync(cancellationToken);
+            stream.Position = position;
+            part.EntryStartPosition = position;
+        }
+        else
+        {
+            // For non-seekable streams, we can't read the trailer or track position.
+            // Set to 0 since the stream will be read sequentially from its current position.
+            part.EntryStartPosition = 0;
+        }
+        return part;
+    }
+
     private GZipFilePart(Stream stream, IArchiveEncoding archiveEncoding)
         : base(archiveEncoding) => _stream = stream;
 
@@ -47,12 +75,7 @@ internal sealed partial class GZipFilePart : FilePart
     internal override string? FilePartName => _name;
 
     internal override Stream GetCompressedStream() =>
-        new DeflateStream(
-            _stream,
-            CompressionMode.Decompress,
-            CompressionLevel.Default,
-            leaveOpen: true
-        );
+        new DeflateStream(_stream, CompressionMode.Decompress, CompressionLevel.Default);
 
     internal override Stream GetRawStream() => _stream;
 
@@ -66,6 +89,16 @@ internal sealed partial class GZipFilePart : FilePart
         UncompressedSize = BinaryPrimitives.ReadUInt32LittleEndian(trailer.Slice(4));
     }
 
+    private async ValueTask ReadTrailerAsync(CancellationToken cancellationToken = default)
+    {
+        // Read and potentially verify the GZIP trailer: CRC32 and  size mod 2^32
+        var trailer = new byte[8];
+        _ = await _stream.ReadFullyAsync(trailer, 0, 8, cancellationToken);
+
+        Crc = BinaryPrimitives.ReadUInt32LittleEndian(trailer);
+        UncompressedSize = BinaryPrimitives.ReadUInt32LittleEndian(trailer.AsSpan().Slice(4));
+    }
+
     private void ReadAndValidateGzipHeader()
     {
         // read the header on the first read
@@ -118,6 +151,61 @@ internal sealed partial class GZipFilePart : FilePart
         }
     }
 
+    private async ValueTask ReadAndValidateGzipHeaderAsync(
+        CancellationToken cancellationToken = default
+    )
+    {
+        // read the header on the first read
+        var header = new byte[10];
+        var n = await _stream.ReadAsync(header, 0, 10, cancellationToken);
+
+        // workitem 8501: handle edge case (decompress empty stream)
+        if (n == 0)
+        {
+            return;
+        }
+
+        if (n != 10)
+        {
+            throw new ZlibException("Not a valid GZIP stream.");
+        }
+
+        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+        {
+            throw new ZlibException("Bad GZIP header.");
+        }
+
+        var timet = BinaryPrimitives.ReadInt32LittleEndian(header.AsSpan().Slice(4));
+        DateModified = TarHeader.EPOCH.AddSeconds(timet);
+        if ((header[3] & 0x04) == 0x04)
+        {
+            // read and discard extra field
+            var lengthField = new byte[2];
+            _ = await _stream.ReadAsync(lengthField, 0, 2, cancellationToken);
+
+            var extraLength = (short)(lengthField[0] + (lengthField[1] * 256));
+            var extra = new byte[extraLength];
+
+            if (!await _stream.ReadFullyAsync(extra, cancellationToken))
+            {
+                throw new ZlibException("Unexpected end-of-file reading GZIP header.");
+            }
+        }
+        if ((header[3] & 0x08) == 0x08)
+        {
+            _name = await ReadZeroTerminatedStringAsync(_stream, cancellationToken);
+        }
+        if ((header[3] & 0x10) == 0x010)
+        {
+            await ReadZeroTerminatedStringAsync(_stream, cancellationToken);
+        }
+        if ((header[3] & 0x02) == 0x02)
+        {
+            var buf = new byte[1];
+            _ = await _stream.ReadAsync(buf, 0, 1, cancellationToken); // CRC16, ignore
+        }
+    }
+
     private string ReadZeroTerminatedString(Stream stream)
     {
         Span<byte> buf1 = stackalloc byte[1];
@@ -143,4 +231,33 @@ internal sealed partial class GZipFilePart : FilePart
         var buffer = list.ToArray();
         return ArchiveEncoding.Decode(buffer);
     }
+
+    private async ValueTask<string> ReadZeroTerminatedStringAsync(
+        Stream stream,
+        CancellationToken cancellationToken = default
+    )
+    {
+        var buf1 = new byte[1];
+        var list = new List<byte>();
+        var done = false;
+        do
+        {
+            // workitem 7740
+            var n = await stream.ReadAsync(buf1, 0, 1, cancellationToken);
+            if (n != 1)
+            {
+                throw new ZlibException("Unexpected EOF reading GZIP header.");
+            }
+            if (buf1[0] == 0)
+            {
+                done = true;
+            }
+            else
+            {
+                list.Add(buf1[0]);
+            }
+        } while (!done);
+        var buffer = list.ToArray();
+        return ArchiveEncoding.Decode(buffer);
+    }
 }

src/SharpCompress/Common/IVolume.cs

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

src/SharpCompress/Common/Rar/AsyncMarkingBinaryReader.cs

@@ -1,190 +0,0 @@
-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");
-    }
-}