Add IsArchiveAsync overloads for Zip and GZip factories

- Added IsArchiveAsync interface method to IFactory
- Implemented async versions of IsZipFile, IsZipMulti, IsGZipFile
- Updated ZipFactory and GZipFactory to override IsArchiveAsync
- Updated ReaderFactory.OpenAsync to use IsArchiveAsync
- Fixed Zip_Reader_Disposal_Test2_Async to use ReaderFactory.OpenAsync
- Fixed TestStream to properly forward ReadAsync calls
- Removed BufferedStream wrapping from AsyncBinaryReader as it uses sync Read
- Added default implementation in Factory base class

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

.config/dotnet-tools.json

@@ -3,10 +3,11 @@
   "isRoot": true,
   "tools": {
     "csharpier": {
-      "version": "0.28.1",
+      "version": "1.2.4",
       "commands": [
-        "dotnet-csharpier"
-      ]
+        "csharpier"
+      ],
+      "rollForward": false
     }
   }
-}
+}

.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/dependabot.yml

@@ -1,6 +1,13 @@
 version: 2
 updates:
-  - package-ecosystem: "github-actions" # search for actions - there are other options available
-    directory: "/" # search in .github/workflows under root `/`
+  - package-ecosystem: "github-actions"
+    directory: "/" 
     schedule:
-      interval: "weekly" # check for action update every week
+      interval: "weekly"
+
+  - package-ecosystem: "nuget"
+    directory: "/"    # change to "/src/YourProject" if .csproj files are in subfolders
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 5
+    # optional: target-branch: "master"

.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/dotnetcore.yml

@@ -14,12 +14,12 @@ jobs:
         os: [windows-latest, ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-dotnet@v4
+    - uses: actions/checkout@v6
+    - uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 8.0.x
+        dotnet-version: 10.0.x
     - run: dotnet run --project build/build.csproj
-    - uses: actions/upload-artifact@v4
+    - uses: actions/upload-artifact@v6
       with:
         name: ${{ matrix.os }}-sharpcompress.nupkg
         path: artifacts/*

.gitignore

@@ -11,11 +11,11 @@ TestResults/
 packages/*/
 project.lock.json
 tests/TestArchives/Scratch
+tests/TestArchives/*/Scratch
+tests/TestArchives/*/Scratch2
 .vs
 tools
-.vscode
 .idea/
 
 .DS_Store
 *.snupkg
-/tests/TestArchives/6d23a38c-f064-4ef1-ad89-b942396f53b9/Scratch

.vscode/extensions.json

@@ -0,0 +1,9 @@
+{
+  "recommendations": [
+    "ms-dotnettools.csdevkit",
+    "ms-dotnettools.csharp",
+    "ms-dotnettools.vscode-dotnet-runtime",
+    "csharpier.csharpier-vscode",
+    "formulahendry.dotnet-test-explorer"
+  ]
+}

.vscode/launch.json

@@ -0,0 +1,97 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug Tests (net10.0)",
+      "type": "coreclr",
+      "request": "launch",
+      "preLaunchTask": "build",
+      "program": "dotnet",
+      "args": [
+        "test",
+        "${workspaceFolder}/tests/SharpCompress.Test/SharpCompress.Test.csproj",
+        "-f",
+        "net10.0",
+        "--no-build",
+        "--verbosity=normal"
+      ],
+      "cwd": "${workspaceFolder}",
+      "console": "internalConsole",
+      "stopAtEntry": false
+    },
+    {
+      "name": "Debug Specific Test (net10.0)",
+      "type": "coreclr",
+      "request": "launch",
+      "preLaunchTask": "build",
+      "program": "dotnet",
+      "args": [
+        "test",
+        "${workspaceFolder}/tests/SharpCompress.Test/SharpCompress.Test.csproj",
+        "-f",
+        "net10.0",
+        "--no-build",
+        "--filter",
+        "FullyQualifiedName~${input:testName}"
+      ],
+      "cwd": "${workspaceFolder}",
+      "console": "internalConsole",
+      "stopAtEntry": false
+    },
+    {
+      "name": "Debug Performance Tests",
+      "type": "coreclr",
+      "request": "launch",
+      "preLaunchTask": "build",
+      "program": "dotnet",
+      "args": [
+        "run",
+        "--project",
+        "${workspaceFolder}/tests/SharpCompress.Performance/SharpCompress.Performance.csproj",
+        "--no-build"
+      ],
+      "cwd": "${workspaceFolder}",
+      "console": "internalConsole",
+      "stopAtEntry": false
+    },
+    {
+      "name": "Debug Build Script",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "dotnet",
+      "args": [
+        "run",
+        "--project",
+        "${workspaceFolder}/build/build.csproj",
+        "--",
+        "${input:buildTarget}"
+      ],
+      "cwd": "${workspaceFolder}",
+      "console": "internalConsole",
+      "stopAtEntry": false
+    }
+  ],
+  "inputs": [
+    {
+      "id": "testName",
+      "type": "promptString",
+      "description": "Enter test name or pattern (e.g., TestMethodName or ClassName)",
+      "default": ""
+    },
+    {
+      "id": "buildTarget",
+      "type": "pickString",
+      "description": "Select build target",
+      "options": [
+        "clean",
+        "restore",
+        "build",
+        "test",
+        "format",
+        "publish",
+        "default"
+      ],
+      "default": "build"
+    }
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,29 @@
+{
+  "dotnet.defaultSolution": "SharpCompress.sln",
+  "files.exclude": {
+    "**/bin": true,
+    "**/obj": true
+  },
+  "files.watcherExclude": {
+    "**/bin/**": true,
+    "**/obj/**": true,
+    "**/artifacts/**": true
+  },
+  "search.exclude": {
+    "**/bin": true,
+    "**/obj": true,
+    "**/artifacts": true
+  },
+  "editor.formatOnSave": false,
+  "[csharp]": {
+    "editor.defaultFormatter": "csharpier.csharpier-vscode",
+    "editor.formatOnSave": true,
+    "editor.codeActionsOnSave": {
+      "source.fixAll": "explicit"
+    }
+  },
+  "csharpier.enableDebugLogs": false,
+  "omnisharp.enableRoslynAnalyzers": true,
+  "omnisharp.enableEditorConfigSupport": true,
+  "dotnet-test-explorer.testProjectPath": "tests/**/*.csproj"
+}

.vscode/tasks.json

@@ -0,0 +1,178 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "build",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "build",
+        "${workspaceFolder}/SharpCompress.sln",
+        "/property:GenerateFullPaths=true",
+        "/consoleloggerparameters:NoSummary;ForceNoAlign"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      }
+    },
+    {
+      "label": "build-release",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "build",
+        "${workspaceFolder}/SharpCompress.sln",
+        "-c",
+        "Release",
+        "/property:GenerateFullPaths=true",
+        "/consoleloggerparameters:NoSummary;ForceNoAlign"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": "build"
+    },
+    {
+      "label": "build-library",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "build",
+        "${workspaceFolder}/src/SharpCompress/SharpCompress.csproj",
+        "/property:GenerateFullPaths=true",
+        "/consoleloggerparameters:NoSummary;ForceNoAlign"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": "build"
+    },
+    {
+      "label": "restore",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "restore",
+        "${workspaceFolder}/SharpCompress.sln"
+      ],
+      "problemMatcher": "$msCompile"
+    },
+    {
+      "label": "clean",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "clean",
+        "${workspaceFolder}/SharpCompress.sln"
+      ],
+      "problemMatcher": "$msCompile"
+    },
+    {
+      "label": "test",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "test",
+        "${workspaceFolder}/tests/SharpCompress.Test/SharpCompress.Test.csproj",
+        "--no-build",
+        "--verbosity=normal"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": {
+        "kind": "test",
+        "isDefault": true
+      },
+      "dependsOn": "build"
+    },
+    {
+      "label": "test-net10",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "test",
+        "${workspaceFolder}/tests/SharpCompress.Test/SharpCompress.Test.csproj",
+        "-f",
+        "net10.0",
+        "--no-build",
+        "--verbosity=normal"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": "test",
+      "dependsOn": "build"
+    },
+    {
+      "label": "test-net48",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "test",
+        "${workspaceFolder}/tests/SharpCompress.Test/SharpCompress.Test.csproj",
+        "-f",
+        "net48",
+        "--no-build",
+        "--verbosity=normal"
+      ],
+      "problemMatcher": "$msCompile",
+      "group": "test",
+      "dependsOn": "build"
+    },
+    {
+      "label": "format",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "csharpier",
+        "."
+      ],
+      "problemMatcher": []
+    },
+    {
+      "label": "format-check",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "csharpier",
+        "check",
+        "."
+      ],
+      "problemMatcher": []
+    },
+    {
+      "label": "run-build-script",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "run",
+        "--project",
+        "${workspaceFolder}/build/build.csproj"
+      ],
+      "problemMatcher": "$msCompile"
+    },
+    {
+      "label": "pack",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "pack",
+        "${workspaceFolder}/src/SharpCompress/SharpCompress.csproj",
+        "-c",
+        "Release",
+        "-o",
+        "${workspaceFolder}/artifacts/"
+      ],
+      "problemMatcher": "$msCompile",
+      "dependsOn": "build-release"
+    },
+    {
+      "label": "performance-tests",
+      "command": "dotnet",
+      "type": "process",
+      "args": [
+        "run",
+        "--project",
+        "${workspaceFolder}/tests/SharpCompress.Performance/SharpCompress.Performance.csproj",
+        "-c",
+        "Release"
+      ],
+      "problemMatcher": "$msCompile"
+    }
+  ]
+}

AGENTS.md

@@ -0,0 +1,181 @@
+---
+description: 'Guidelines for building SharpCompress - A C# compression library'
+applyTo: '**/*.cs'
+---
+
+# SharpCompress Development
+
+## About SharpCompress
+SharpCompress is a pure C# compression library supporting multiple archive formats (Zip, Tar, GZip, BZip2, 7Zip, Rar, LZip, XZ, ZStandard) for .NET Framework 4.62, .NET Standard 2.1, .NET 6.0, and .NET 8.0. The library provides both seekable Archive APIs and forward-only Reader/Writer APIs for streaming scenarios.
+
+## C# Instructions
+- Always use the latest version C#, currently C# 13 features.
+- Write clear and concise comments for each function.
+- Follow the existing code style and patterns in the codebase.
+
+## General Instructions
+- Make only high confidence suggestions when reviewing code changes.
+- Write code with good maintainability practices, including comments on why certain design decisions were made.
+- Handle edge cases and write clear exception handling.
+- For libraries or external dependencies, mention their usage and purpose in comments.
+- Preserve backward compatibility when making changes to public APIs.
+
+## Naming Conventions
+
+- Follow PascalCase for component names, method names, and public members.
+- Use camelCase for private fields and local variables.
+- Prefix interface names with "I" (e.g., IUserService).
+
+## Code Formatting
+
+**Copilot agents: You MUST run the `format` task after making code changes to ensure consistency.**
+
+- Use CSharpier for code formatting to ensure consistent style across the project
+- CSharpier is configured as a local tool in `.config/dotnet-tools.json`
+
+### Commands
+
+1. **Restore tools** (first time only):
+   ```bash
+   dotnet tool restore
+   ```
+
+2. **Check if files are formatted correctly** (doesn't modify files):
+   ```bash
+   dotnet csharpier check .
+   ```
+   - Exit code 0: All files are properly formatted
+   - Exit code 1: Some files need formatting (will show which files and differences)
+
+3. **Format files** (modifies files):
+   ```bash
+   dotnet csharpier format .
+   ```
+   - Formats all files in the project to match CSharpier style
+   - Run from project root directory
+
+4. **Configure your IDE** to format on save using CSharpier for the best experience
+
+### Additional Notes
+- The project also uses `.editorconfig` for editor settings (indentation, encoding, etc.)
+- Let CSharpier handle code style while `.editorconfig` handles editor behavior
+- Always run `dotnet csharpier check .` before committing to verify formatting
+
+## Project Setup and Structure
+
+- The project targets multiple frameworks: .NET Framework 4.62, .NET Standard 2.1, .NET 6.0, and .NET 8.0
+- Main library is in `src/SharpCompress/`
+- Tests are in `tests/SharpCompress.Test/`
+- Performance tests are in `tests/SharpCompress.Performance/`
+- Test archives are in `tests/TestArchives/`
+- Build project is in `build/`
+- Use `dotnet build` to build the solution
+- Use `dotnet test` to run tests
+- Solution file: `SharpCompress.sln`
+
+### Directory Structure
+```
+src/SharpCompress/
+  ├── Archives/        # IArchive implementations (Zip, Tar, Rar, 7Zip, GZip)
+  ├── Readers/         # IReader implementations (forward-only)
+  ├── Writers/         # IWriter implementations (forward-only)
+  ├── Compressors/     # Low-level compression streams (BZip2, Deflate, LZMA, etc.)
+  ├── Factories/       # Format detection and factory pattern
+  ├── Common/          # Shared types (ArchiveType, Entry, Options)
+  ├── Crypto/          # Encryption implementations
+  └── IO/              # Stream utilities and wrappers
+
+tests/SharpCompress.Test/
+  ├── Zip/, Tar/, Rar/, SevenZip/, GZip/, BZip2/  # Format-specific tests
+  ├── TestBase.cs      # Base test class with helper methods
+  └── TestArchives/    # Test data (not checked into main test project)
+```
+
+### Factory Pattern
+All format types implement factory interfaces (`IArchiveFactory`, `IReaderFactory`, `IWriterFactory`) for auto-detection:
+- `ReaderFactory.Open()` - Auto-detects format by probing stream
+- `WriterFactory.Open()` - Creates writer for specified `ArchiveType`
+- Factories located in: `src/SharpCompress/Factories/`
+
+## Nullable Reference Types
+
+- Declare variables non-nullable, and check for `null` at entry points.
+- Always use `is null` or `is not null` instead of `== null` or `!= null`.
+- Trust the C# null annotations and don't add null checks when the type system says a value cannot be null.
+
+## SharpCompress-Specific Guidelines
+
+### Supported Formats
+SharpCompress supports multiple archive and compression formats:
+- **Archive Formats**: Zip, Tar, 7Zip, Rar (read-only)
+- **Compression**: DEFLATE, BZip2, LZMA/LZMA2, PPMd, ZStandard (decompress only), Deflate64 (decompress only)
+- **Combined Formats**: Tar.GZip, Tar.BZip2, Tar.LZip, Tar.XZ, Tar.ZStandard
+- See FORMATS.md for complete format support matrix
+
+### Stream Handling Rules
+- **Disposal**: As of version 0.21, SharpCompress closes wrapped streams by default
+- Use `ReaderOptions` or `WriterOptions` with `LeaveStreamOpen = true` to control stream disposal
+- Use `NonDisposingStream` wrapper when working with compression streams directly to prevent disposal
+- Always dispose of readers, writers, and archives in `using` blocks
+- For forward-only operations, use Reader/Writer APIs; for random access, use Archive APIs
+
+### Async/Await Patterns
+- All I/O operations support async/await with `CancellationToken`
+- Async methods follow the naming convention: `MethodNameAsync`
+- Key async methods:
+  - `WriteEntryToAsync` - Extract entry asynchronously
+  - `WriteAllToDirectoryAsync` - Extract all entries asynchronously
+  - `WriteAsync` - Write entry asynchronously
+  - `WriteAllAsync` - Write directory asynchronously
+  - `OpenEntryStreamAsync` - Open entry stream asynchronously
+- Always provide `CancellationToken` parameter in async methods
+
+### Archive APIs vs Reader/Writer APIs
+- **Archive API**: Use for random access with seekable streams (e.g., `ZipArchive`, `TarArchive`)
+- **Reader API**: Use for forward-only reading on non-seekable streams (e.g., `ZipReader`, `TarReader`)
+- **Writer API**: Use for forward-only writing on streams (e.g., `ZipWriter`, `TarWriter`)
+- 7Zip only supports Archive API due to format limitations
+
+### Tar-Specific Considerations
+- Tar format requires file size in the header
+- If no size is specified to TarWriter and the stream is not seekable, an exception will be thrown
+- Tar combined with compression (GZip, BZip2, LZip, XZ) is supported
+
+### Zip-Specific Considerations
+- Supports Zip64 for large files (seekable streams only)
+- Supports PKWare and WinZip AES encryption
+- Multiple compression methods: None, Shrink, Reduce, Implode, DEFLATE, Deflate64, BZip2, LZMA, PPMd
+- Encrypted LZMA is not supported
+
+### Performance Considerations
+- For large files, use Reader/Writer APIs with non-seekable streams to avoid loading entire file in memory
+- Leverage async I/O for better scalability
+- Consider compression level trade-offs (speed vs. size)
+- Use appropriate buffer sizes for stream operations
+
+## Testing
+
+- Always include test cases for critical paths of the application.
+- Test with multiple archive formats when making changes to core functionality.
+- Include tests for both Archive and Reader/Writer APIs when applicable.
+- Test async operations with cancellation tokens.
+- Do not emit "Act", "Arrange" or "Assert" comments.
+- Copy existing style in nearby files for test method names and capitalization.
+- Use test archives from `tests/TestArchives` directory for consistency.
+- Test stream disposal and `LeaveStreamOpen` behavior.
+- Test edge cases: empty archives, large files, corrupted archives, encrypted archives.
+
+### Test Organization
+- Base class: `TestBase` - Provides `TEST_ARCHIVES_PATH`, `SCRATCH_FILES_PATH`, temp directory management
+- Framework: xUnit with AwesomeAssertions
+- Test archives: `tests/TestArchives/` - Use existing archives, don't create new ones unnecessarily
+- Match naming style of nearby test files
+
+## Common Pitfalls
+
+1. **Don't mix Archive and Reader APIs** - Archive needs seekable stream, Reader doesn't
+2. **Solid archives (Rar, 7Zip)** - Use `ExtractAllEntries()` for best performance, not individual entry extraction
+3. **Stream disposal** - Always set `LeaveStreamOpen` explicitly when needed (default is to close)
+4. **Tar + non-seekable stream** - Must provide file size or it will throw
+5. **Multi-framework differences** - Some features differ between .NET Framework and modern .NET (e.g., Mono.Posix)
+6. **Format detection** - Use `ReaderFactory.Open()` for auto-detection, test with actual archive files

Directory.Packages.props

@@ -1,18 +1,20 @@
 <Project>
   <ItemGroup>
-    <PackageVersion Include="Bullseye" Version="5.0.0" />
-    <PackageVersion Include="FluentAssertions" Version="6.12.0" />
+    <PackageVersion Include="Bullseye" Version="6.1.0" />
+    <PackageVersion Include="AwesomeAssertions" Version="9.3.0" />
     <PackageVersion Include="Glob" Version="1.1.9" />
-    <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
-    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.15" />
+    <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" 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="12.0.0" />
-    <PackageVersion Include="System.Memory" Version="4.5.5" />
-    <PackageVersion Include="System.Text.Encoding.CodePages" Version="8.0.0" />
-    <PackageVersion Include="xunit" Version="2.7.1" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.8" />
-    <PackageVersion Include="xunit.SkippableFact" Version="1.4.13" />
-    <PackageVersion Include="ZstdSharp.Port" Version="0.8.0" />
+    <PackageVersion Include="SimpleExec" Version="12.1.0" />
+    <PackageVersion Include="System.Text.Encoding.CodePages" Version="10.0.0" />
+    <PackageVersion Include="System.Buffers" Version="4.6.1" />
+    <PackageVersion Include="System.Memory" Version="4.6.3" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
+    <PackageVersion Include="Microsoft.NET.ILLink.Tasks" Version="10.0.0" />
+    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <PackageVersion Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3" />
   </ItemGroup>
 </Project>

FORMATS.md

@@ -11,21 +11,39 @@
 | Archive Format         | Compression Format(s)                             | Compress/Decompress | Archive API     | Reader API | Writer API    |
 | ---------------------- | ------------------------------------------------- | ------------------- | --------------- | ---------- | ------------- |
 | Rar                    | Rar                                               | Decompress (1)      | RarArchive      | RarReader  | N/A           |
-| Zip (2)                | None, DEFLATE, Deflate64, BZip2, LZMA/LZMA2, PPMd | Both                | ZipArchive      | ZipReader  | ZipWriter     |
+| Zip (2)                | None, Shrink, Reduce, Implode, DEFLATE, Deflate64, BZip2, LZMA/LZMA2, PPMd                           | Both                | ZipArchive      | ZipReader  | ZipWriter     | 
 | Tar                    | None                                              | Both                | TarArchive      | TarReader  | TarWriter (3) |
 | Tar.GZip               | DEFLATE                                           | Both                | TarArchive      | TarReader  | TarWriter (3) |
 | Tar.BZip2              | BZip2                                             | Both                | TarArchive      | TarReader  | TarWriter (3) |
+| Tar.Zstandard          | ZStandard                                         | Decompress          | TarArchive      | TarReader  | N/A |
 | Tar.LZip               | LZMA                                              | Both                | TarArchive      | TarReader  | TarWriter (3) |
 | Tar.XZ                 | LZMA2                                             | Decompress          | TarArchive      | TarReader  | TarWriter (3) |
 | GZip (single file)     | DEFLATE                                           | Both                | GZipArchive     | GZipReader | GZipWriter    |
 | 7Zip (4)               | LZMA, LZMA2, BZip2, PPMd, BCJ, BCJ2, Deflate      | Decompress          | SevenZipArchive | N/A        | N/A           |
 
 1. SOLID Rars are only supported in the RarReader API.
-2. Zip format supports pkware and WinzipAES encryption. However, encrypted LZMA is not supported. Zip64 reading/writing is supported but only with seekable streams as the Zip spec doesn't support Zip64 data in post data descriptors. Deflate64 is only supported for reading.
+2. Zip format supports pkware and WinzipAES encryption. However, encrypted LZMA is not supported. Zip64 reading/writing is supported but only with seekable streams as the Zip spec doesn't support Zip64 data in post data descriptors. Deflate64 is only supported for reading. See [Zip Format Notes](#zip-format-notes) for details on multi-volume archives and streaming behavior.
 3. The Tar format requires a file size in the header. If no size is specified to the TarWriter and the stream is not seekable, then an exception will be thrown.
-4. The 7Zip format doesn't allow for reading as a forward-only stream so 7Zip is only supported through the Archive API
+4. The 7Zip format doesn't allow for reading as a forward-only stream so 7Zip is only supported through the Archive API. See [7Zip Format Notes](#7zip-format-notes) for details on async extraction behavior.
 5. LZip has no support for extra data like the file name or timestamp. There is a default filename used when looking at the entry Key on the archive.
 
+### Zip Format Notes
+
+- Multi-volume/split ZIP archives require ZipArchive (seekable streams) as ZipReader cannot seek across volume files.
+- ZipReader processes entries from LocalEntry headers (which include directory entries ending with `/`) and intentionally skips DirectoryEntry headers from the central directory, as they are redundant in streaming mode - all entry data comes from LocalEntry headers which ZipReader has already processed.
+
+### 7Zip Format Notes
+
+- **Async Extraction Performance**: When using async extraction methods (e.g., `ExtractAllEntries()` with `MoveToNextEntryAsync()`), each file creates its own decompression stream to avoid state corruption in the LZMA decoder. This is less efficient than synchronous extraction, which can reuse a single decompression stream for multiple files in the same folder.
+  
+  **Performance Impact**: For archives with many small files in the same compression folder, async extraction will be slower than synchronous extraction because it must:
+  1. Create a new LZMA decoder for each file
+  2. Skip through the decompressed data to reach each file's starting position
+  
+  **Recommendation**: For best performance with 7Zip archives, use synchronous extraction methods (`MoveToNextEntry()` and `WriteEntryToDirectory()`) when possible. Use async methods only when you need to avoid blocking the thread (e.g., in UI applications or async-only contexts).
+  
+  **Technical Details**: 7Zip archives group files into "folders" (compression units), where all files in a folder share one continuous LZMA-compressed stream. The LZMA decoder maintains internal state (dictionary window, decoder positions) that assumes sequential, non-interruptible processing. Async operations can yield control during awaits, which would corrupt this shared state. To avoid this, async extraction creates a fresh decoder stream for each file.
+
 ## Compression Streams
 
 For those who want to directly compress/decompress bits. The single file formats are represented here as well. However, BZip2, LZip and XZ have no metadata (GZip has a little) so using them without something like a Tar file makes little sense.
@@ -41,6 +59,7 @@ For those who want to directly compress/decompress bits. The single file formats
 | ADCStream       | Decompress          |
 | LZipStream      | Both                |
 | XZStream        | Decompress          |
+| ZStandardStream | Decompress          |
 
 ## Archive Formats vs Compression
 

README.md

@@ -1,9 +1,11 @@
 # SharpCompress
 
-SharpCompress is a compression library in pure C# for .NET Framework 4.62, .NET Standard 2.1, .NET 6.0 and NET 8.0 that can unrar, un7zip, unzip, untar unbzip2, ungzip, unlzip with forward-only reading and file random access APIs. Write support for zip/tar/bzip2/gzip/lzip are implemented.
+SharpCompress is a compression library in pure C# for .NET Framework 4.8, .NET 8.0 and .NET 10.0 that can unrar, un7zip, unzip, untar unbzip2, ungzip, unlzip, unzstd, unarc and unarj with forward-only reading and file random access APIs. Write support for zip/tar/bzip2/gzip/lzip are implemented.
 
 The major feature is support for non-seekable streams so large files can be processed on the fly (i.e. download stream).
 
+**NEW:** All I/O operations now support async/await for improved performance and scalability. See the [Async Usage](#async-usage) section below.
+
 GitHub Actions Build -
 [![SharpCompress](https://github.com/adamhathcock/sharpcompress/actions/workflows/dotnetcore.yml/badge.svg)](https://github.com/adamhathcock/sharpcompress/actions/workflows/dotnetcore.yml)
 [![Static Badge](https://img.shields.io/badge/API%20Docs-DNDocs-190088?logo=readme&logoColor=white)](https://dndocs.com/d/sharpcompress/api/index.html)
@@ -20,16 +22,94 @@ In general, I recommend GZip (Deflate)/BZip2 (BZip)/LZip (LZMA) as the simplicit
 
 Zip is okay, but it's a very hap-hazard format and the variation in headers and implementations makes it hard to get correct. Uses Deflate by default but supports a lot of compression methods.
 
-RAR is not recommended as it's a propriatory format and the compression is closed source. Use Tar/LZip for LZMA
+RAR is not recommended as it's a proprietary format and the compression is closed source. Use Tar/LZip for LZMA
 
 7Zip and XZ both are overly complicated. 7Zip does not support streamable formats. XZ has known holes explained here: (http://www.nongnu.org/lzip/xz_inadequate.html) Use Tar/LZip for LZMA compression instead.
 
+ZStandard is an efficient format that works well for streaming with a flexible compression level to tweak the speed/performance trade off you are looking for.  We currently only implement decompression for ZStandard but as we leverage the [ZstdSharp](https://github.com/oleg-st/ZstdSharp) library one could likely add compression support without much trouble (PRs are welcome!).
+
 ## A Simple Request
 
 Hi everyone. I hope you're using SharpCompress and finding it useful. Please give me feedback on what you'd like to see changed especially as far as usability goes. New feature suggestions are always welcome as well. I would also like to know what projects SharpCompress is being used in. I like seeing how it is used to give me ideas for future versions. Thanks!
 
 Please do not email me directly to ask for help. If you think there is a real issue, please report it here.
 
+## Async Usage
+
+SharpCompress now provides full async/await support for all I/O operations, allowing for better performance and scalability in modern applications.
+
+### Async Reading Examples
+
+Extract entries asynchronously:
+```csharp
+using (Stream stream = File.OpenRead("archive.zip"))
+using (var reader = ReaderFactory.Open(stream))
+{
+    while (reader.MoveToNextEntry())
+    {
+        if (!reader.Entry.IsDirectory)
+        {
+            // Async extraction
+            await reader.WriteEntryToDirectoryAsync(
+                @"C:\temp",
+                new ExtractionOptions() { ExtractFullPath = true, Overwrite = true },
+                cancellationToken
+            );
+        }
+    }
+}
+```
+
+Extract all entries to directory asynchronously:
+```csharp
+using (Stream stream = File.OpenRead("archive.tar.gz"))
+using (var reader = ReaderFactory.Open(stream))
+{
+    await reader.WriteAllToDirectoryAsync(
+        @"C:\temp",
+        new ExtractionOptions() { ExtractFullPath = true, Overwrite = true },
+        cancellationToken
+    );
+}
+```
+
+Open entry stream asynchronously:
+```csharp
+using (var archive = ZipArchive.Open("archive.zip"))
+{
+    foreach (var entry in archive.Entries.Where(e => !e.IsDirectory))
+    {
+        using (var entryStream = await entry.OpenEntryStreamAsync(cancellationToken))
+        {
+            // Process stream asynchronously
+            await entryStream.CopyToAsync(outputStream, cancellationToken);
+        }
+    }
+}
+```
+
+### Async Writing Examples
+
+Write files asynchronously:
+```csharp
+using (Stream stream = File.OpenWrite("output.zip"))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
+{
+    await writer.WriteAsync("file1.txt", fileStream, DateTime.Now, cancellationToken);
+}
+```
+
+Write all files from directory asynchronously:
+```csharp
+using (Stream stream = File.OpenWrite("output.tar.gz"))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)))
+{
+    await writer.WriteAllAsync(@"D:\files", "*", SearchOption.AllDirectories, cancellationToken);
+}
+```
+
+All async methods support `CancellationToken` for graceful cancellation of long-running operations.
+
 ## Want to contribute?
 
 I'm always looking for help or ideas. Please submit code or email with ideas. Unfortunately, just letting me know you'd like to help is not enough because I really have no overall plan of what needs to be done. I'll definitely accept code submissions and add you as a member of the project!
@@ -40,6 +120,7 @@ I'm always looking for help or ideas. Please submit code or email with ideas. Un
 * 7Zip writing
 * Zip64 (Need writing and extend Reading)
 * Multi-volume Zip support.
+* ZStandard writing
 
 ## Version Log
 

SharpCompress.sln

@@ -20,8 +20,15 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Config", "Config", "{CDB425
 		.editorconfig = .editorconfig
 		Directory.Packages.props = Directory.Packages.props
 		NuGet.config = NuGet.config
+		.github\workflows\dotnetcore.yml = .github\workflows\dotnetcore.yml
+		USAGE.md = USAGE.md
+		README.md = README.md
+		FORMATS.md = FORMATS.md
+		AGENTS.md = AGENTS.md
 	EndProjectSection
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SharpCompress.Performance", "tests\SharpCompress.Performance\SharpCompress.Performance.csproj", "{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -40,6 +47,10 @@ Global
 		{D4D613CB-5E94-47FB-85BE-B8423D20C545}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{D4D613CB-5E94-47FB-85BE-B8423D20C545}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D4D613CB-5E94-47FB-85BE-B8423D20C545}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -47,5 +58,6 @@ Global
 	GlobalSection(NestedProjects) = preSolution
 		{FD19DDD8-72B2-4024-8665-0D1F7A2AA998} = {3C5BE746-03E5-4895-9988-0B57F162F86C}
 		{F2B1A1EB-0FA6-40D0-8908-E13247C7226F} = {0F0901FF-E8D9-426A-B5A2-17C7F47C1529}
+		{5BDE6DBC-9E5F-4E21-AB71-F138A3E72B17} = {0F0901FF-E8D9-426A-B5A2-17C7F47C1529}
 	EndGlobalSection
 EndGlobal

SharpCompress.sln.DotSettings

@@ -15,17 +15,17 @@
 	
 	<s:String x:Key="/Default/CodeStyle/CodeCleanup/SilentCleanupProfile/@EntryValue">Basic Clean</s:String>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/APPLY_ON_COMPLETION/@EntryValue">True</s:Boolean>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/ARGUMENTS_NAMED/@EntryValue">Named</s:String>
+	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/ARGUMENTS_NAMED/@EntryValue">Positional</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_FOR/@EntryValue">Required</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_FOREACH/@EntryValue">Required</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_IFELSE/@EntryValue">Required</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_WHILE/@EntryValue">Required</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_FIRST_ARG_BY_PAREN/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_FIRST_ARG_BY_PAREN/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_LINQ_QUERY/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_ARGUMENT/@EntryValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_ARRAY_AND_OBJECT_INITIALIZER/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_ARRAY_AND_OBJECT_INITIALIZER/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_CALLS_CHAIN/@EntryValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_EXPRESSION/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_EXPRESSION/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_EXTENDS_LIST/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_FOR_STMT/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/ALIGN_MULTILINE_PARAMETER/@EntryValue">True</s:Boolean>
@@ -42,7 +42,7 @@
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/FORCE_IFELSE_BRACES_STYLE/@EntryValue">ALWAYS_ADD</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/FORCE_USING_BRACES_STYLE/@EntryValue">ALWAYS_ADD</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/FORCE_WHILE_BRACES_STYLE/@EntryValue">ALWAYS_ADD</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/INDENT_ANONYMOUS_METHOD_BLOCK/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/INDENT_ANONYMOUS_METHOD_BLOCK/@EntryValue">False</s:Boolean>
 	<s:Int64 x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_BLANK_LINES_IN_CODE/@EntryValue">1</s:Int64>
 	<s:Int64 x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_BLANK_LINES_IN_DECLARATIONS/@EntryValue">1</s:Int64>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_ACCESSOR_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
@@ -50,12 +50,12 @@
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_CONSTRUCTOR_INITIALIZER_ON_SAME_LINE/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_FIELD_ATTRIBUTE_ON_SAME_LINE/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_FIELD_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ACCESSORHOLDER_ON_SINGLE_LINE/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ACCESSORHOLDER_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ACCESSOR_ATTRIBUTE_ON_SAME_LINE/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_EMBEDDED_STATEMENT_ON_SAME_LINE/@EntryValue">NEVER</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_INITIALIZER_ON_SINGLE_LINE/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_INITIALIZER_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
 	
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_WHILE_ON_NEW_LINE/@EntryValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_WHILE_ON_NEW_LINE/@EntryValue">False</s:Boolean>
 	
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SIMPLE_EMBEDDED_STATEMENT_STYLE/@EntryValue">LINE_BREAK</s:String>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_AFTER_TYPECAST_PARENTHESES/@EntryValue">False</s:Boolean>
@@ -67,13 +67,13 @@
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_BEFORE_TYPEOF_PARENTHESES/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/STICK_COMMENT/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARGUMENTS_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARRAY_INITIALIZER_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
+	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARRAY_INITIALIZER_STYLE/@EntryValue">CHOP_ALWAYS</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_EXTENDS_LIST_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_LINES/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_PARAMETERS_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
-	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForBuiltInTypes/@EntryValue">UseVarWhenEvident</s:String>
-	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForOtherTypes/@EntryValue">UseVarWhenEvident</s:String>
-	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForSimpleTypes/@EntryValue">UseVarWhenEvident</s:String>
+	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForBuiltInTypes/@EntryValue">UseVar</s:String>
+	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForOtherTypes/@EntryValue">UseVar</s:String>
+	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForSimpleTypes/@EntryValue">UseVar</s:String>
 	
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="_" Suffix="" Style="aaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateStaticFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AA_BB" /&gt;</s:String>
@@ -122,6 +122,7 @@
 	<s:String x:Key="/Default/CodeStyle/Naming/XamlNaming/UserRules/=NAMESPACE_005FALIAS/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/XamlNaming/UserRules/=XAML_005FFIELD/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/XamlNaming/UserRules/=XAML_005FRESOURCE/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb" /&gt;</s:String>
+	<s:String x:Key="/Default/CustomTools/CustomToolsData/@EntryValue"></s:String>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpAttributeForSingleLineMethodUpgrade/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>

USAGE.md

@@ -1,5 +1,18 @@
 # SharpCompress Usage
 
+## Async/Await Support
+
+SharpCompress now provides full async/await support for all I/O operations. All `Read`, `Write`, and extraction operations have async equivalents ending in `Async` that accept an optional `CancellationToken`. This enables better performance and scalability for I/O-bound operations.
+
+**Key Async Methods:**
+- `reader.WriteEntryToAsync(stream, cancellationToken)` - Extract entry asynchronously  
+- `reader.WriteAllToDirectoryAsync(path, options, cancellationToken)` - Extract all asynchronously
+- `writer.WriteAsync(filename, stream, modTime, cancellationToken)` - Write entry asynchronously
+- `writer.WriteAllAsync(directory, pattern, searchOption, cancellationToken)` - Write directory asynchronously
+- `entry.OpenEntryStreamAsync(cancellationToken)` - Open entry stream asynchronously
+
+See [Async Examples](#async-examples) section below for usage patterns.
+
 ## Stream Rules (changed with 0.21)
 
 When dealing with Streams, the rule should be that you don't close a stream you didn't create. This, in effect, should mean you should always put a Stream in a using block to dispose it. 
@@ -27,7 +40,7 @@ To deal with the "correct" rules as well as the expectations of users, I've deci
 
 To be explicit though, consider always using the overloads that use `ReaderOptions` or `WriterOptions` and explicitly set `LeaveStreamOpen` the way you want.
 
-If using Compression Stream classes directly and you don't want the wrapped stream to be closed.  Use the `NonDisposingStream` as a wrapped to prevent the stream being disposed.  The change in 0.21 simplified a lot even though the usage is a bit more convoluted.
+If using Compression Stream classes directly and you don't want the wrapped stream to be closed.  Use the `NonDisposingStream` as a wrapper to prevent the stream being disposed.  The change in 0.21 simplified a lot even though the usage is a bit more convoluted.
 
 ## Samples
 
@@ -71,18 +84,66 @@ using (var archive = ZipArchive.Create())
 memoryStream.Position = 0;
 ```
 
-### Extract all files from a Rar file to a directory using RarArchive
+### Extract all files from a rar file to a directory using RarArchive
+
+Note: Extracting a solid rar or 7z file needs to be done in sequential order to get acceptable decompression speed.
+`ExtractAllEntries` is primarily intended for solid archives (like solid Rar) or 7Zip archives, where sequential extraction provides the best performance. For general/simple extraction with any supported archive type, use `archive.WriteToDirectory()` instead.
+
+```C#
+using (var archive = RarArchive.Open("Test.rar"))
+{
+    // Simple extraction with RarArchive; this WriteToDirectory pattern works for all archive types
+    archive.WriteToDirectory(@"D:\temp", new ExtractionOptions()
+    {
+        ExtractFullPath = true,
+        Overwrite = true
+    });
+}
+```
+
+### Iterate over all files from a Rar file using RarArchive
 
 ```C#
 using (var archive = RarArchive.Open("Test.rar"))
 {
     foreach (var entry in archive.Entries.Where(entry => !entry.IsDirectory))
     {
-        entry.WriteToDirectory("D:\\temp", new ExtractionOptions()
+        Console.WriteLine($"{entry.Key}: {entry.Size} bytes");
+    }
+}
+```
+
+### Extract solid Rar or 7Zip archives with manual progress reporting
+
+`ExtractAllEntries` only works for solid archives (Rar) or 7Zip archives. For optimal performance with these archive types, use this method:
+
+```C#
+using (var archive = RarArchive.Open("archive.rar")) // Must be solid Rar or 7Zip
+{
+    if (archive.IsSolid || archive.Type == ArchiveType.SevenZip)
+    {
+        // Calculate total size for progress reporting
+        double totalSize = archive.Entries.Where(e => !e.IsDirectory).Sum(e => e.Size);
+        long completed = 0;
+
+        using (var reader = archive.ExtractAllEntries())
         {
-            ExtractFullPath = true,
-            Overwrite = true
-        });
+            while (reader.MoveToNextEntry())
+            {
+                if (!reader.Entry.IsDirectory)
+                {
+                    reader.WriteEntryToDirectory(@"D:\output", new ExtractionOptions()
+                    {
+                        ExtractFullPath = true,
+                        Overwrite = true
+                    });
+
+                    completed += reader.Entry.Size;
+                    double progress = completed / totalSize;
+                    Console.WriteLine($"Progress: {progress:P}");
+                }
+            }
+        }
     }
 }
 ```
@@ -156,3 +217,131 @@ foreach(var entry in tr.Entries)
     Console.WriteLine($"{entry.Key}");
 }
 ```
+
+## Async Examples
+
+### Async Reader Examples
+
+**Extract single entry asynchronously:**
+```C#
+using (Stream stream = File.OpenRead("archive.zip"))
+using (var reader = ReaderFactory.Open(stream))
+{
+    while (reader.MoveToNextEntry())
+    {
+        if (!reader.Entry.IsDirectory)
+        {
+            using (var entryStream = reader.OpenEntryStream())
+            {
+                using (var outputStream = File.Create("output.bin"))
+                {
+                    await reader.WriteEntryToAsync(outputStream, cancellationToken);
+                }
+            }
+        }
+    }
+}
+```
+
+**Extract all entries asynchronously:**
+```C#
+using (Stream stream = File.OpenRead("archive.tar.gz"))
+using (var reader = ReaderFactory.Open(stream))
+{
+    await reader.WriteAllToDirectoryAsync(
+        @"D:\temp",
+        new ExtractionOptions()
+        {
+            ExtractFullPath = true,
+            Overwrite = true
+        },
+        cancellationToken
+    );
+}
+```
+
+**Open and process entry stream asynchronously:**
+```C#
+using (var archive = ZipArchive.Open("archive.zip"))
+{
+    foreach (var entry in archive.Entries.Where(e => !e.IsDirectory))
+    {
+        using (var entryStream = await entry.OpenEntryStreamAsync(cancellationToken))
+        {
+            // Process the decompressed stream asynchronously
+            await ProcessStreamAsync(entryStream, cancellationToken);
+        }
+    }
+}
+```
+
+### Async Writer Examples
+
+**Write single file asynchronously:**
+```C#
+using (Stream archiveStream = File.OpenWrite("output.zip"))
+using (var writer = WriterFactory.Open(archiveStream, ArchiveType.Zip, CompressionType.Deflate))
+{
+    using (Stream fileStream = File.OpenRead("input.txt"))
+    {
+        await writer.WriteAsync("entry.txt", fileStream, DateTime.Now, cancellationToken);
+    }
+}
+```
+
+**Write entire directory asynchronously:**
+```C#
+using (Stream stream = File.OpenWrite("backup.tar.gz"))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Tar, new WriterOptions(CompressionType.GZip)))
+{
+    await writer.WriteAllAsync(
+        @"D:\files",
+        "*",
+        SearchOption.AllDirectories,
+        cancellationToken
+    );
+}
+```
+
+**Write with progress tracking and cancellation:**
+```C#
+var cts = new CancellationTokenSource();
+
+// Set timeout or cancel from UI
+cts.CancelAfter(TimeSpan.FromMinutes(5));
+
+using (Stream stream = File.OpenWrite("archive.zip"))
+using (var writer = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
+{
+    try
+    {
+        await writer.WriteAllAsync(@"D:\data", "*", SearchOption.AllDirectories, cts.Token);
+    }
+    catch (OperationCanceledException)
+    {
+        Console.WriteLine("Operation was cancelled");
+    }
+}
+```
+
+### Archive Async Examples
+
+**Extract from archive asynchronously:**
+```C#
+using (var archive = ZipArchive.Open("archive.zip"))
+{
+    // Simple async extraction - works for all archive types
+    await archive.WriteToDirectoryAsync(
+        @"C:\output",
+        new ExtractionOptions() { ExtractFullPath = true, Overwrite = true },
+        cancellationToken
+    );
+}
+```
+
+**Benefits of Async Operations:**
+- Non-blocking I/O for better application responsiveness
+- Improved scalability for server applications
+- Support for cancellation via CancellationToken
+- Better resource utilization in async/await contexts
+- Compatible with modern .NET async patterns

build/Program.cs

@@ -11,11 +11,12 @@ const string Restore = "restore";
 const string Build = "build";
 const string Test = "test";
 const string Format = "format";
+const string CheckFormat = "check-format";
 const string Publish = "publish";
 
 Target(
     Clean,
-    ForEach("**/bin", "**/obj"),
+    ["**/bin", "**/obj"],
     dir =>
     {
         IEnumerable<string> GetDirectories(string d)
@@ -44,14 +45,22 @@ Target(
     () =>
     {
         Run("dotnet", "tool restore");
-        Run("dotnet", "csharpier --check .");
+        Run("dotnet", "csharpier format .");
     }
 );
-Target(Restore, DependsOn(Format), () => Run("dotnet", "restore"));
+Target(
+    CheckFormat,
+    () =>
+    {
+        Run("dotnet", "tool restore");
+        Run("dotnet", "csharpier check .");
+    }
+);
+Target(Restore, [CheckFormat], () => Run("dotnet", "restore"));
 
 Target(
     Build,
-    DependsOn(Restore),
+    [Restore],
     () =>
     {
         Run("dotnet", "build src/SharpCompress/SharpCompress.csproj -c Release --no-restore");
@@ -60,8 +69,8 @@ Target(
 
 Target(
     Test,
-    DependsOn(Build),
-    ForEach("net8.0", "net462"),
+    [Build],
+    ["net10.0", "net48"],
     framework =>
     {
         IEnumerable<string> GetFiles(string d)
@@ -69,7 +78,7 @@ Target(
             return Glob.Files(".", d);
         }
 
-        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && framework == "net462")
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && framework == "net48")
         {
             return;
         }
@@ -83,13 +92,13 @@ Target(
 
 Target(
     Publish,
-    DependsOn(Test),
+    [Test],
     () =>
     {
         Run("dotnet", "pack src/SharpCompress/SharpCompress.csproj -c Release -o artifacts/");
     }
 );
 
-Target("default", DependsOn(Publish), () => Console.WriteLine("Done!"));
+Target("default", [Publish], () => Console.WriteLine("Done!"));
 
 await RunTargetsAndExitAsync(args);

build/build.csproj

@@ -1,14 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
-
   <ItemGroup>
     <PackageReference Include="Bullseye" />
     <PackageReference Include="Glob" />
-    <PackageReference Include="SimpleExec"  />
+    <PackageReference Include="SimpleExec" />
   </ItemGroup>
-
 </Project>

build/packages.lock.json

@@ -1,12 +1,12 @@
 {
   "version": 2,
   "dependencies": {
-    "net8.0": {
+    "net10.0": {
       "Bullseye": {
         "type": "Direct",
-        "requested": "[5.0.0, )",
-        "resolved": "5.0.0",
-        "contentHash": "bqyt+m17ym+5aN45C5oZRAjuLDt8jKiCm/ys1XfymIXSkrTFwvI/QsbY3ucPSHDz7SF7uON7B57kXFv5H2k1ew=="
+        "requested": "[6.1.0, )",
+        "resolved": "6.1.0",
+        "contentHash": "fltnAJDe0BEX5eymXGUq+il2rSUA0pHqUonNDRH2TrvRu8SkU17mYG0IVpdmG2ibtfhdjNrv4CuTCxHOwcozCA=="
       },
       "Glob": {
         "type": "Direct",
@@ -16,9 +16,9 @@
       },
       "SimpleExec": {
         "type": "Direct",
-        "requested": "[12.0.0, )",
-        "resolved": "12.0.0",
-        "contentHash": "ptxlWtxC8vM6Y6e3h9ZTxBBkOWnWrm/Sa1HT+2i1xcXY3Hx2hmKDZP5RShPf8Xr9D+ivlrXNy57ktzyH8kyt+Q=="
+        "requested": "[12.1.0, )",
+        "resolved": "12.1.0",
+        "contentHash": "PcCSAlMcKr5yTd571MgEMoGmoSr+omwziq2crB47lKP740lrmjuBocAUXHj+Q6LR6aUDFyhszot2wbtFJTClkA=="
       }
     }
   }

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.100",
+    "version": "10.0.100",
     "rollForward": "latestFeature"
   }
 }

src/SharpCompress/Algorithms/Adler32.cs

@@ -141,7 +141,7 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
             4,
             3,
             2,
-            1 // tap2
+            1, // tap2
         };
 #endif
 

src/SharpCompress/Archives/AbstractArchive.cs

@@ -8,7 +8,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
-public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtractionListener
+public abstract class AbstractArchive<TEntry, TVolume> : IArchive
     where TEntry : IArchiveEntry
     where TVolume : IVolume
 {
@@ -17,11 +17,6 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
     private bool _disposed;
     private readonly SourceStream? _sourceStream;
 
-    public event EventHandler<ArchiveExtractionEventArgs<IArchiveEntry>>? EntryExtractionBegin;
-    public event EventHandler<ArchiveExtractionEventArgs<IArchiveEntry>>? EntryExtractionEnd;
-
-    public event EventHandler<CompressedBytesReadEventArgs>? CompressedBytesRead;
-    public event EventHandler<FilePartExtractionBeginEventArgs>? FilePartExtractionBegin;
     protected ReaderOptions ReaderOptions { get; }
 
     internal AbstractArchive(ArchiveType type, SourceStream sourceStream)
@@ -43,17 +38,11 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
 
     public ArchiveType Type { get; }
 
-    void IArchiveExtractionListener.FireEntryExtractionBegin(IArchiveEntry entry) =>
-        EntryExtractionBegin?.Invoke(this, new ArchiveExtractionEventArgs<IArchiveEntry>(entry));
-
-    void IArchiveExtractionListener.FireEntryExtractionEnd(IArchiveEntry entry) =>
-        EntryExtractionEnd?.Invoke(this, new ArchiveExtractionEventArgs<IArchiveEntry>(entry));
-
     private static Stream CheckStreams(Stream stream)
     {
         if (!stream.CanSeek || !stream.CanRead)
         {
-            throw new ArgumentException("Archive streams must be Readable and Seekable");
+            throw new ArchiveException("Archive streams must be Readable and Seekable");
         }
         return stream;
     }
@@ -99,38 +88,12 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
         }
     }
 
-    void IArchiveExtractionListener.EnsureEntriesLoaded()
+    private void EnsureEntriesLoaded()
     {
         _lazyEntries.EnsureFullyLoaded();
         _lazyVolumes.EnsureFullyLoaded();
     }
 
-    void IExtractionListener.FireCompressedBytesRead(
-        long currentPartCompressedBytes,
-        long compressedReadBytes
-    ) =>
-        CompressedBytesRead?.Invoke(
-            this,
-            new CompressedBytesReadEventArgs(
-                currentFilePartCompressedBytesRead: currentPartCompressedBytes,
-                compressedBytesRead: compressedReadBytes
-            )
-        );
-
-    void IExtractionListener.FireFilePartExtractionBegin(
-        string name,
-        long size,
-        long compressedSize
-    ) =>
-        FilePartExtractionBegin?.Invoke(
-            this,
-            new FilePartExtractionBeginEventArgs(
-                compressedSize: compressedSize,
-                size: size,
-                name: name
-            )
-        );
-
     /// <summary>
     /// Use this method to extract all entries in an archive in order.
     /// This is primarily for SOLID Rar Archives or 7Zip Archives as they need to be
@@ -144,7 +107,13 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
     /// <returns></returns>
     public IReader ExtractAllEntries()
     {
-        ((IArchiveExtractionListener)this).EnsureEntriesLoaded();
+        if (!IsSolid && Type != ArchiveType.SevenZip)
+        {
+            throw new SharpCompressException(
+                "ExtractAllEntries can only be used on solid archives or 7Zip archives (which require random access)."
+            );
+        }
+        EnsureEntriesLoaded();
         return CreateReaderForSolidExtraction();
     }
 
@@ -155,6 +124,11 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
     /// </summary>
     public virtual bool IsSolid => false;
 
+    /// <summary>
+    /// Archive is ENCRYPTED (this means the Archive has password-protected files).
+    /// </summary>
+    public virtual bool IsEncrypted => false;
+
     /// <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>
@@ -162,7 +136,7 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
     {
         get
         {
-            ((IArchiveExtractionListener)this).EnsureEntriesLoaded();
+            EnsureEntriesLoaded();
             return Entries.All(x => x.IsComplete);
         }
     }

src/SharpCompress/Archives/AbstractWritableArchive.cs

@@ -2,6 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 using SharpCompress.Writers;
@@ -94,6 +96,9 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         DateTime? modified
     ) => AddEntry(key, source, closeStream, size, modified);
 
+    IArchiveEntry IWritableArchive.AddDirectoryEntry(string key, DateTime? modified) =>
+        AddDirectoryEntry(key, modified);
+
     public TEntry AddEntry(
         string key,
         Stream source,
@@ -134,6 +139,22 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         return false;
     }
 
+    public TEntry AddDirectoryEntry(string key, DateTime? modified = null)
+    {
+        if (key.Length > 0 && key[0] is '/' or '\\')
+        {
+            key = key.Substring(1);
+        }
+        if (DoesKeyMatchExisting(key))
+        {
+            throw new ArchiveException("Cannot add entry with duplicate key: " + key);
+        }
+        var entry = CreateDirectoryEntry(key, modified);
+        newEntries.Add(entry);
+        RebuildModifiedCollection();
+        return entry;
+    }
+
     public void SaveTo(Stream stream, WriterOptions options)
     {
         //reset streams of new entries
@@ -141,6 +162,18 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         SaveTo(stream, options, OldEntries, newEntries);
     }
 
+    public async Task 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,
@@ -151,7 +184,7 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
     {
         if (!source.CanRead || !source.CanSeek)
         {
-            throw new ArgumentException(
+            throw new ArchiveException(
                 "Streams must be readable and seekable to use the Writing Archive API"
             );
         }
@@ -166,6 +199,8 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         bool closeStream
     );
 
+    protected abstract TEntry CreateDirectoryEntry(string key, DateTime? modified);
+
     protected abstract void SaveTo(
         Stream stream,
         WriterOptions options,
@@ -173,6 +208,14 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         IEnumerable<TEntry> newEntries
     );
 
+    protected abstract Task SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        IEnumerable<TEntry> oldEntries,
+        IEnumerable<TEntry> newEntries,
+        CancellationToken cancellationToken = default
+    );
+
     public override void Dispose()
     {
         base.Dispose();

src/SharpCompress/Archives/ArchiveFactory.cs

@@ -2,8 +2,11 @@ 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;
@@ -19,10 +22,31 @@ public static class ArchiveFactory
     public static IArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
         readerOptions ??= new ReaderOptions();
-
+        stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
         return FindFactory<IArchiveFactory>(stream).Open(stream, readerOptions);
     }
 
+    /// <summary>
+    /// Opens an Archive for random access asynchronously
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    /// <returns></returns>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        readerOptions ??= new ReaderOptions();
+        stream = SharpCompressStream.Create(stream, bufferSize: readerOptions.BufferSize);
+        var factory = FindFactory<IArchiveFactory>(stream);
+        return await factory
+            .OpenAsync(stream, readerOptions, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     public static IWritableArchive Create(ArchiveType type)
     {
         var factory = Factory
@@ -44,10 +68,26 @@ public static class ArchiveFactory
     /// <param name="options"></param>
     public static IArchive Open(string filePath, ReaderOptions? options = null)
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        filePath.NotNullOrEmpty(nameof(filePath));
         return Open(new FileInfo(filePath), options);
     }
 
+    /// <summary>
+    /// Opens an Archive from a filepath asynchronously.
+    /// </summary>
+    /// <param name="filePath"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static Task<IArchive> OpenAsync(
+        string filePath,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        filePath.NotNullOrEmpty(nameof(filePath));
+        return OpenAsync(new FileInfo(filePath), options, cancellationToken);
+    }
+
     /// <summary>
     /// Constructor with a FileInfo object to an existing file.
     /// </summary>
@@ -60,6 +100,24 @@ public static class ArchiveFactory
         return FindFactory<IArchiveFactory>(fileInfo).Open(fileInfo, options);
     }
 
+    /// <summary>
+    /// Opens an Archive from a FileInfo object asynchronously.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        var factory = FindFactory<IArchiveFactory>(fileInfo);
+        return await factory.OpenAsync(fileInfo, options, cancellationToken).ConfigureAwait(false);
+    }
+
     /// <summary>
     /// Constructor with IEnumerable FileInfo objects, multi and split support.
     /// </summary>
@@ -67,7 +125,7 @@ public static class ArchiveFactory
     /// <param name="options"></param>
     public static IArchive Open(IEnumerable<FileInfo> fileInfos, ReaderOptions? options = null)
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var filesArray = fileInfos.ToArray();
         if (filesArray.Length == 0)
         {
@@ -80,12 +138,46 @@ public static class ArchiveFactory
             return Open(fileInfo, options);
         }
 
-        fileInfo.CheckNotNull(nameof(fileInfo));
+        fileInfo.NotNull(nameof(fileInfo));
         options ??= new ReaderOptions { LeaveStreamOpen = false };
 
         return FindFactory<IMultiArchiveFactory>(fileInfo).Open(filesArray, options);
     }
 
+    /// <summary>
+    /// Opens a multi-part archive from files asynchronously.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        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 OpenAsync(fileInfo, options, cancellationToken).ConfigureAwait(false);
+        }
+
+        fileInfo.NotNull(nameof(fileInfo));
+        options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+        var factory = FindFactory<IMultiArchiveFactory>(fileInfo);
+        return await factory
+            .OpenAsync(filesArray, options, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     /// <summary>
     /// Constructor with IEnumerable FileInfo objects, multi and split support.
     /// </summary>
@@ -93,7 +185,7 @@ public static class ArchiveFactory
     /// <param name="options"></param>
     public static IArchive Open(IEnumerable<Stream> streams, ReaderOptions? options = null)
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var streamsArray = streams.ToArray();
         if (streamsArray.Length == 0)
         {
@@ -106,12 +198,47 @@ public static class ArchiveFactory
             return Open(firstStream, options);
         }
 
-        firstStream.CheckNotNull(nameof(firstStream));
+        firstStream.NotNull(nameof(firstStream));
         options ??= new ReaderOptions();
 
         return FindFactory<IMultiArchiveFactory>(firstStream).Open(streamsArray, options);
     }
 
+    /// <summary>
+    /// Opens a multi-part archive from streams asynchronously.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="options"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IEnumerable<Stream> streams,
+        ReaderOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        streams.NotNull(nameof(streams));
+        var streamsArray = streams.ToArray();
+        if (streamsArray.Length == 0)
+        {
+            throw new InvalidOperationException("No streams");
+        }
+
+        var firstStream = streamsArray[0];
+        if (streamsArray.Length == 1)
+        {
+            return await OpenAsync(firstStream, options, cancellationToken).ConfigureAwait(false);
+        }
+
+        firstStream.NotNull(nameof(firstStream));
+        options ??= new ReaderOptions();
+
+        var factory = FindFactory<IMultiArchiveFactory>(firstStream);
+        return await factory
+            .OpenAsync(streamsArray, options, cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     /// <summary>
     /// Extract to specific directory, retaining filename
     /// </summary>
@@ -122,16 +249,13 @@ public static class ArchiveFactory
     )
     {
         using var archive = Open(sourceArchive);
-        foreach (var entry in archive.Entries)
-        {
-            entry.WriteToDirectory(destinationDirectory, options);
-        }
+        archive.WriteToDirectory(destinationDirectory, options);
     }
 
     private static T FindFactory<T>(FileInfo finfo)
         where T : IFactory
     {
-        finfo.CheckNotNull(nameof(finfo));
+        finfo.NotNull(nameof(finfo));
         using Stream stream = finfo.OpenRead();
         return FindFactory<T>(stream);
     }
@@ -139,7 +263,7 @@ public static class ArchiveFactory
     private static T FindFactory<T>(Stream stream)
         where T : IFactory
     {
-        stream.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
         if (!stream.CanRead || !stream.CanSeek)
         {
             throw new ArgumentException("Stream should be readable and seekable");
@@ -168,17 +292,25 @@ public static class ArchiveFactory
         );
     }
 
-    public static bool IsArchive(string filePath, out ArchiveType? type)
+    public static bool IsArchive(
+        string filePath,
+        out ArchiveType? type,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        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.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
 
         if (!stream.CanRead || !stream.CanSeek)
         {
@@ -189,9 +321,10 @@ public static class ArchiveFactory
 
         foreach (var factory in Factory.Factories)
         {
+            var isArchive = factory.IsArchive(stream);
             stream.Position = startPosition;
 
-            if (factory.IsArchive(stream, null))
+            if (isArchive)
             {
                 type = factory.KnownArchiveType;
                 return true;
@@ -208,7 +341,7 @@ public static class ArchiveFactory
     /// <returns></returns>
     public static IEnumerable<string> GetFileParts(string part1)
     {
-        part1.CheckNotNullOrEmpty(nameof(part1));
+        part1.NotNullOrEmpty(nameof(part1));
         return GetFileParts(new FileInfo(part1)).Select(a => a.FullName);
     }
 
@@ -219,7 +352,7 @@ public static class ArchiveFactory
     /// <returns></returns>
     public static IEnumerable<FileInfo> GetFileParts(FileInfo part1)
     {
-        part1.CheckNotNull(nameof(part1));
+        part1.NotNull(nameof(part1));
         yield return part1;
 
         foreach (var factory in Factory.Factories.OfType<IFactory>())
@@ -239,4 +372,6 @@ public static class ArchiveFactory
             }
         }
     }
+
+    public static IArchiveFactory AutoFactory { get; } = new AutoArchiveFactory();
 }

src/SharpCompress/Archives/AutoArchiveFactory.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Common;
+using SharpCompress.Readers;
+
+namespace SharpCompress.Archives;
+
+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 Task<bool> IsArchiveAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    ) => throw new NotSupportedException();
+
+    public FileInfo? GetFilePart(int index, FileInfo part1) => throw new NotSupportedException();
+
+    public IArchive Open(Stream stream, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.Open(stream, readerOptions);
+
+    public Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    ) => ArchiveFactory.OpenAsync(stream, readerOptions, cancellationToken);
+
+    public IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null) =>
+        ArchiveFactory.Open(fileInfo, readerOptions);
+
+    public Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    ) => ArchiveFactory.OpenAsync(fileInfo, readerOptions, cancellationToken);
+}

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -2,6 +2,8 @@ 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.GZip;
 using SharpCompress.IO;
@@ -21,7 +23,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     /// <param name="readerOptions"></param>
     public static GZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        filePath.NotNullOrEmpty(nameof(filePath));
         return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
@@ -32,7 +34,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     /// <param name="readerOptions"></param>
     public static GZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
     {
-        fileInfo.CheckNotNull(nameof(fileInfo));
+        fileInfo.NotNull(nameof(fileInfo));
         return new GZipArchive(
             new SourceStream(
                 fileInfo,
@@ -52,7 +54,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
         ReaderOptions? readerOptions = null
     )
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var files = fileInfos.ToArray();
         return new GZipArchive(
             new SourceStream(
@@ -70,7 +72,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     /// <param name="readerOptions"></param>
     public static GZipArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var strms = streams.ToArray();
         return new GZipArchive(
             new SourceStream(
@@ -88,12 +90,82 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     /// <param name="readerOptions"></param>
     public static GZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
-        stream.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
         return new GZipArchive(
             new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
         );
     }
 
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(stream, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfo, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(streams, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a GZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfos, readerOptions)).ConfigureAwait(false);
+    }
+
     public static GZipArchive Create() => new();
 
     /// <summary>
@@ -101,7 +173,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     /// </summary>
     /// <param name="sourceStream"></param>
     private GZipArchive(SourceStream sourceStream)
-        : base(ArchiveType.Tar, sourceStream) { }
+        : base(ArchiveType.GZip, sourceStream) { }
 
     protected override IEnumerable<GZipVolume> LoadVolumes(SourceStream sourceStream)
     {
@@ -130,6 +202,16 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
         SaveTo(stream, new WriterOptions(CompressionType.GZip));
     }
 
+    public Task SaveToAsync(string filePath, CancellationToken cancellationToken = default) =>
+        SaveToAsync(new FileInfo(filePath), cancellationToken);
+
+    public async Task SaveToAsync(FileInfo fileInfo, CancellationToken cancellationToken = default)
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        await SaveToAsync(stream, new WriterOptions(CompressionType.GZip), cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     public static bool IsGZipFile(Stream stream)
     {
         // read the header on the first read
@@ -149,6 +231,28 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
         return true;
     }
 
+    public static async Task<bool> IsGZipFileAsync(
+        Stream stream,
+        CancellationToken cancellationToken = default
+    )
+    {
+        // read the header on the first read
+        byte[] header = new byte[10];
+
+        // workitem 8501: handle edge case (decompress empty stream)
+        if (!await stream.ReadFullyAsync(header, cancellationToken).ConfigureAwait(false))
+        {
+            return false;
+        }
+
+        if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
     internal GZipArchive()
         : base(ArchiveType.GZip) { }
 
@@ -162,11 +266,16 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     {
         if (Entries.Any())
         {
-            throw new InvalidOperationException("Only one entry is allowed in a GZip Archive");
+            throw new InvalidFormatException("Only one entry is allowed in a GZip Archive");
         }
         return new GZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream);
     }
 
+    protected override GZipArchiveEntry CreateDirectoryEntry(
+        string directoryPath,
+        DateTime? modified
+    ) => throw new NotSupportedException("GZip archives do not support directory entries.");
+
     protected override void SaveTo(
         Stream stream,
         WriterOptions options,
@@ -176,7 +285,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
     {
         if (Entries.Count > 1)
         {
-            throw new InvalidOperationException("Only one entry is allowed in a GZip Archive");
+            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))
@@ -190,6 +299,28 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
         }
     }
 
+    protected override async Task 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;

src/SharpCompress/Archives/GZip/GZipArchiveEntry.cs

@@ -1,5 +1,7 @@
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.GZip;
 
 namespace SharpCompress.Archives.GZip;
@@ -13,11 +15,18 @@ public class GZipArchiveEntry : GZipEntry, IArchiveEntry
     {
         //this is to reset the stream to be read multiple times
         var part = (GZipFilePart)Parts.Single();
-        if (part.GetRawStream().Position != part.EntryStartPosition)
+        var rawStream = part.GetRawStream();
+        if (rawStream.CanSeek && rawStream.Position != part.EntryStartPosition)
         {
-            part.GetRawStream().Position = part.EntryStartPosition;
+            rawStream.Position = part.EntryStartPosition;
         }
-        return Parts.Single().GetCompressedStream();
+        return Parts.Single().GetCompressedStream().NotNull();
+    }
+
+    public virtual Task<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
+    {
+        // GZip synchronous implementation is fast enough, just wrap it
+        return Task.FromResult(OpenEntryStream());
     }
 
     #region IArchiveEntry Members

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 NonDisposingStream.Create(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()

src/SharpCompress/Archives/IArchive.cs

@@ -7,12 +7,6 @@ namespace SharpCompress.Archives;
 
 public interface IArchive : IDisposable
 {
-    event EventHandler<ArchiveExtractionEventArgs<IArchiveEntry>> EntryExtractionBegin;
-    event EventHandler<ArchiveExtractionEventArgs<IArchiveEntry>> EntryExtractionEnd;
-
-    event EventHandler<CompressedBytesReadEventArgs> CompressedBytesRead;
-    event EventHandler<FilePartExtractionBeginEventArgs> FilePartExtractionBegin;
-
     IEnumerable<IArchiveEntry> Entries { get; }
     IEnumerable<IVolume> Volumes { get; }
 

src/SharpCompress/Archives/IArchiveEntry.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 
 namespace SharpCompress.Archives;
@@ -11,6 +13,12 @@ public interface IArchiveEntry : IEntry
     /// </summary>
     Stream OpenEntryStream();
 
+    /// <summary>
+    /// Opens the current entry as a stream that will decompress as it is read asynchronously.
+    /// Read the entire stream or use SkipEntry on EntryStream.
+    /// </summary>
+    Task<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default);
+
     /// <summary>
     /// The archive can find all the parts of the archive needed to extract this entry.
     /// </summary>

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -1,4 +1,7 @@
+using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 
@@ -6,61 +9,153 @@ namespace SharpCompress.Archives;
 
 public static class IArchiveEntryExtensions
 {
-    public static void WriteTo(this IArchiveEntry archiveEntry, Stream streamToWriteTo)
+    private const int BufferSize = 81920;
+
+    /// <param name="archiveEntry">The archive entry to extract.</param>
+    extension(IArchiveEntry archiveEntry)
     {
-        if (archiveEntry.IsDirectory)
+        /// <summary>
+        /// Extract entry to the specified stream.
+        /// </summary>
+        /// <param name="streamToWriteTo">The stream to write the entry content to.</param>
+        /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
+        public void WriteTo(Stream streamToWriteTo, IProgress<ProgressReport>? progress = null)
         {
-            throw new ExtractionException("Entry is a file directory and cannot be extracted.");
+            if (archiveEntry.IsDirectory)
+            {
+                throw new ExtractionException("Entry is a file directory and cannot be extracted.");
+            }
+
+            using var entryStream = archiveEntry.OpenEntryStream();
+            var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
+            sourceStream.CopyTo(streamToWriteTo, BufferSize);
         }
 
-        var streamListener = (IArchiveExtractionListener)archiveEntry.Archive;
-        streamListener.EnsureEntriesLoaded();
-        streamListener.FireEntryExtractionBegin(archiveEntry);
-        streamListener.FireFilePartExtractionBegin(
-            archiveEntry.Key ?? "Key",
-            archiveEntry.Size,
-            archiveEntry.CompressedSize
-        );
-        var entryStream = archiveEntry.OpenEntryStream();
-        using (entryStream)
+        /// <summary>
+        /// Extract entry to the specified stream asynchronously.
+        /// </summary>
+        /// <param name="streamToWriteTo">The stream to write the entry content to.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
+        public async Task WriteToAsync(
+            Stream streamToWriteTo,
+            IProgress<ProgressReport>? progress = null,
+            CancellationToken cancellationToken = default
+        )
         {
-            using Stream s = new ListeningStream(streamListener, entryStream);
-            s.TransferTo(streamToWriteTo);
+            if (archiveEntry.IsDirectory)
+            {
+                throw new ExtractionException("Entry is a file directory and cannot be extracted.");
+            }
+
+            using var entryStream = await archiveEntry.OpenEntryStreamAsync(cancellationToken);
+            var sourceStream = WrapWithProgress(entryStream, archiveEntry, progress);
+            await sourceStream
+                .CopyToAsync(streamToWriteTo, BufferSize, cancellationToken)
+                .ConfigureAwait(false);
         }
-        streamListener.FireEntryExtractionEnd(archiveEntry);
     }
 
-    /// <summary>
-    /// Extract to specific directory, retaining filename
-    /// </summary>
-    public static void WriteToDirectory(
-        this IArchiveEntry entry,
-        string destinationDirectory,
-        ExtractionOptions? options = null
-    ) =>
-        ExtractionMethods.WriteEntryToDirectory(
-            entry,
-            destinationDirectory,
-            options,
-            entry.WriteToFile
-        );
+    private static Stream WrapWithProgress(
+        Stream source,
+        IArchiveEntry entry,
+        IProgress<ProgressReport>? progress
+    )
+    {
+        if (progress is null)
+        {
+            return source;
+        }
 
-    /// <summary>
-    /// Extract to specific file
-    /// </summary>
-    public static void WriteToFile(
-        this IArchiveEntry entry,
-        string destinationFileName,
-        ExtractionOptions? options = null
-    ) =>
-        ExtractionMethods.WriteEntryToFile(
-            entry,
-            destinationFileName,
-            options,
-            (x, fm) =>
-            {
-                using var fs = File.Open(destinationFileName, fm);
-                entry.WriteTo(fs);
-            }
+        var entryPath = entry.Key ?? string.Empty;
+        var totalBytes = GetEntrySizeSafe(entry);
+        return new ProgressReportingStream(
+            source,
+            progress,
+            entryPath,
+            totalBytes,
+            leaveOpen: true
         );
+    }
+
+    private static long? GetEntrySizeSafe(IArchiveEntry entry)
+    {
+        try
+        {
+            var size = entry.Size;
+            return size >= 0 ? size : null;
+        }
+        catch (NotImplementedException)
+        {
+            return null;
+        }
+    }
+
+    extension(IArchiveEntry entry)
+    {
+        /// <summary>
+        /// Extract to specific directory, retaining filename
+        /// </summary>
+        public void WriteToDirectory(
+            string destinationDirectory,
+            ExtractionOptions? options = null
+        ) =>
+            ExtractionMethods.WriteEntryToDirectory(
+                entry,
+                destinationDirectory,
+                options,
+                entry.WriteToFile
+            );
+
+        /// <summary>
+        /// Extract to specific directory asynchronously, retaining filename
+        /// </summary>
+        public Task WriteToDirectoryAsync(
+            string destinationDirectory,
+            ExtractionOptions? options = null,
+            CancellationToken cancellationToken = default
+        ) =>
+            ExtractionMethods.WriteEntryToDirectoryAsync(
+                entry,
+                destinationDirectory,
+                options,
+                entry.WriteToFileAsync,
+                cancellationToken
+            );
+
+        /// <summary>
+        /// Extract to specific file
+        /// </summary>
+        public void WriteToFile(string destinationFileName, ExtractionOptions? options = null) =>
+            ExtractionMethods.WriteEntryToFile(
+                entry,
+                destinationFileName,
+                options,
+                (x, fm) =>
+                {
+                    using var fs = File.Open(destinationFileName, fm);
+                    entry.WriteTo(fs);
+                }
+            );
+
+        /// <summary>
+        /// Extract to specific file asynchronously
+        /// </summary>
+        public Task WriteToFileAsync(
+            string destinationFileName,
+            ExtractionOptions? options = null,
+            CancellationToken cancellationToken = default
+        ) =>
+            ExtractionMethods.WriteEntryToFileAsync(
+                entry,
+                destinationFileName,
+                options,
+                async (x, fm, ct) =>
+                {
+                    using var fs = File.Open(destinationFileName, fm);
+                    await entry.WriteToAsync(fs, null, ct).ConfigureAwait(false);
+                },
+                cancellationToken
+            );
+    }
 }

src/SharpCompress/Archives/IArchiveExtensions.cs

@@ -1,76 +1,168 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
+using SharpCompress.Readers;
 
 namespace SharpCompress.Archives;
 
 public static class IArchiveExtensions
 {
-    /// <summary>
-    /// Extract to specific directory, retaining filename
-    /// </summary>
-    public static void WriteToDirectory(
-        this IArchive archive,
-        string destinationDirectory,
-        ExtractionOptions? options = null
-    )
-    {
-        foreach (var entry in archive.Entries.Where(x => !x.IsDirectory))
-        {
-            entry.WriteToDirectory(destinationDirectory, options);
-        }
-    }
-
-    /// <summary>
-    /// Extracts the archive to the destination directory. Directories will be created as needed.
-    /// </summary>
     /// <param name="archive">The archive to extract.</param>
-    /// <param name="destination">The folder to extract into.</param>
-    /// <param name="progressReport">Optional progress report callback.</param>
-    /// <param name="cancellationToken">Optional cancellation token.</param>
-    public static void ExtractToDirectory(
-        this IArchive archive,
-        string destination,
-        Action<double>? progressReport = null,
-        CancellationToken cancellationToken = default
-    )
+    extension(IArchive archive)
     {
-        // Prepare for progress reporting
-        var totalBytes = archive.TotalUncompressSize;
-        var bytesRead = 0L;
-
-        // Tracking for created directories.
-        var seenDirectories = new HashSet<string>();
-
-        // Extract
-        var entries = archive.ExtractAllEntries();
-        while (entries.MoveToNextEntry())
+        /// <summary>
+        /// Extract to specific directory with progress reporting
+        /// </summary>
+        /// <param name="destinationDirectory">The folder to extract into.</param>
+        /// <param name="options">Extraction options.</param>
+        /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
+        public void WriteToDirectory(
+            string destinationDirectory,
+            ExtractionOptions? options = null,
+            IProgress<ProgressReport>? progress = null
+        )
         {
-            cancellationToken.ThrowIfCancellationRequested();
-
-            var entry = entries.Entry;
-            if (entry.IsDirectory)
+            // For solid archives (Rar, 7Zip), use the optimized reader-based approach
+            if (archive.IsSolid || archive.Type == ArchiveType.SevenZip)
             {
-                continue;
+                using var reader = archive.ExtractAllEntries();
+                reader.WriteAllToDirectory(destinationDirectory, options);
             }
-
-            // Create each directory
-            var path = Path.Combine(destination, entry.Key.NotNull("Entry Key is null"));
-            if (Path.GetDirectoryName(path) is { } directory && seenDirectories.Add(path))
+            else
             {
-                Directory.CreateDirectory(directory);
+                // For non-solid archives, extract entries directly
+                archive.WriteToDirectoryInternal(destinationDirectory, options, progress);
             }
+        }
 
-            // Write file
-            using var fs = File.OpenWrite(path);
-            entries.WriteEntryTo(fs);
+        private void WriteToDirectoryInternal(
+            string destinationDirectory,
+            ExtractionOptions? options,
+            IProgress<ProgressReport>? progress
+        )
+        {
+            // Prepare for progress reporting
+            var totalBytes = archive.TotalUncompressSize;
+            var bytesRead = 0L;
 
-            // Update progress
-            bytesRead += entry.Size;
-            progressReport?.Invoke(bytesRead / (double)totalBytes);
+            // Tracking for created directories.
+            var seenDirectories = new HashSet<string>();
+
+            // Extract
+            foreach (var entry in archive.Entries)
+            {
+                if (entry.IsDirectory)
+                {
+                    var dirPath = Path.Combine(
+                        destinationDirectory,
+                        entry.Key.NotNull("Entry Key is null")
+                    );
+                    if (
+                        Path.GetDirectoryName(dirPath + "/") is { } parentDirectory
+                        && seenDirectories.Add(dirPath)
+                    )
+                    {
+                        Directory.CreateDirectory(parentDirectory);
+                    }
+                    continue;
+                }
+
+                // Use the entry's WriteToDirectory method which respects ExtractionOptions
+                entry.WriteToDirectory(destinationDirectory, options);
+
+                // Update progress
+                bytesRead += entry.Size;
+                progress?.Report(
+                    new ProgressReport(entry.Key ?? string.Empty, bytesRead, totalBytes)
+                );
+            }
+        }
+
+        /// <summary>
+        /// Extract to specific directory asynchronously with progress reporting and cancellation support
+        /// </summary>
+        /// <param name="destinationDirectory">The folder to extract into.</param>
+        /// <param name="options">Extraction options.</param>
+        /// <param name="progress">Optional progress reporter for tracking extraction progress.</param>
+        /// <param name="cancellationToken">Optional cancellation token.</param>
+        public async Task WriteToDirectoryAsync(
+            string destinationDirectory,
+            ExtractionOptions? options = null,
+            IProgress<ProgressReport>? progress = null,
+            CancellationToken cancellationToken = default
+        )
+        {
+            // For solid archives (Rar, 7Zip), use the optimized reader-based approach
+            if (archive.IsSolid || archive.Type == ArchiveType.SevenZip)
+            {
+                using var reader = archive.ExtractAllEntries();
+                await reader.WriteAllToDirectoryAsync(
+                    destinationDirectory,
+                    options,
+                    cancellationToken
+                );
+            }
+            else
+            {
+                // For non-solid archives, extract entries directly
+                await archive.WriteToDirectoryAsyncInternal(
+                    destinationDirectory,
+                    options,
+                    progress,
+                    cancellationToken
+                );
+            }
+        }
+
+        private async Task WriteToDirectoryAsyncInternal(
+            string destinationDirectory,
+            ExtractionOptions? options,
+            IProgress<ProgressReport>? progress,
+            CancellationToken cancellationToken
+        )
+        {
+            // Prepare for progress reporting
+            var totalBytes = archive.TotalUncompressSize;
+            var bytesRead = 0L;
+
+            // Tracking for created directories.
+            var seenDirectories = new HashSet<string>();
+
+            // Extract
+            foreach (var entry in archive.Entries)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+
+                if (entry.IsDirectory)
+                {
+                    var dirPath = Path.Combine(
+                        destinationDirectory,
+                        entry.Key.NotNull("Entry Key is null")
+                    );
+                    if (
+                        Path.GetDirectoryName(dirPath + "/") is { } parentDirectory
+                        && seenDirectories.Add(dirPath)
+                    )
+                    {
+                        Directory.CreateDirectory(parentDirectory);
+                    }
+                    continue;
+                }
+
+                // Use the entry's WriteToDirectoryAsync method which respects ExtractionOptions
+                await entry
+                    .WriteToDirectoryAsync(destinationDirectory, options, cancellationToken)
+                    .ConfigureAwait(false);
+
+                // Update progress
+                bytesRead += entry.Size;
+                progress?.Report(
+                    new ProgressReport(entry.Key ?? string.Empty, bytesRead, totalBytes)
+                );
+            }
         }
     }
 }

src/SharpCompress/Archives/IArchiveExtractionListener.cs

@@ -1,10 +0,0 @@
-using SharpCompress.Common;
-
-namespace SharpCompress.Archives;
-
-internal interface IArchiveExtractionListener : IExtractionListener
-{
-    void EnsureEntriesLoaded();
-    void FireEntryExtractionBegin(IArchiveEntry entry);
-    void FireEntryExtractionEnd(IArchiveEntry entry);
-}

src/SharpCompress/Archives/IArchiveFactory.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Factories;
 using SharpCompress.Readers;
 
@@ -26,10 +28,34 @@ public interface IArchiveFactory : IFactory
     /// <param name="readerOptions">reading options.</param>
     IArchive Open(Stream stream, ReaderOptions? readerOptions = null);
 
+    /// <summary>
+    /// Opens an Archive for random access asynchronously.
+    /// </summary>
+    /// <param name="stream">An open, readable and seekable stream.</param>
+    /// <param name="readerOptions">reading options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
+
     /// <summary>
     /// Constructor with a FileInfo object to an existing file.
     /// </summary>
     /// <param name="fileInfo">the file to open.</param>
     /// <param name="readerOptions">reading options.</param>
     IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null);
+
+    /// <summary>
+    /// Opens an Archive from a FileInfo object asynchronously.
+    /// </summary>
+    /// <param name="fileInfo">the file to open.</param>
+    /// <param name="readerOptions">reading options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 }

src/SharpCompress/Archives/IMultiArchiveFactory.cs

@@ -1,5 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Factories;
 using SharpCompress.Readers;
 
@@ -27,10 +29,34 @@ public interface IMultiArchiveFactory : IFactory
     /// <param name="readerOptions">reading options.</param>
     IArchive Open(IReadOnlyList<Stream> streams, ReaderOptions? readerOptions = null);
 
+    /// <summary>
+    /// Opens a multi-part archive from streams asynchronously.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions">reading options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
+
     /// <summary>
     /// Constructor with IEnumerable Stream objects, multi and split support.
     /// </summary>
     /// <param name="fileInfos"></param>
     /// <param name="readerOptions">reading options.</param>
     IArchive Open(IReadOnlyList<FileInfo> fileInfos, ReaderOptions? readerOptions = null);
+
+    /// <summary>
+    /// Opens a multi-part archive from files asynchronously.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions">reading options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    );
 }

src/SharpCompress/Archives/IWritableArchive.cs

@@ -1,5 +1,7 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
@@ -16,8 +18,16 @@ public interface IWritableArchive : IArchive
         DateTime? modified = null
     );
 
+    IArchiveEntry AddDirectoryEntry(string key, DateTime? modified = null);
+
     void SaveTo(Stream stream, WriterOptions options);
 
+    Task SaveToAsync(
+        Stream stream,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    );
+
     /// <summary>
     /// Use this to pause entry rebuilding when adding large collections of entries.  Dispose when complete.  A  using statement is recommended.
     /// </summary>

src/SharpCompress/Archives/IWritableArchiveExtensions.cs

@@ -1,5 +1,7 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Writers;
 
 namespace SharpCompress.Archives;
@@ -42,6 +44,24 @@ public static class IWritableArchiveExtensions
         writableArchive.SaveTo(stream, options);
     }
 
+    public static Task SaveToAsync(
+        this IWritableArchive writableArchive,
+        string filePath,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    ) => writableArchive.SaveToAsync(new FileInfo(filePath), options, cancellationToken);
+
+    public static async Task SaveToAsync(
+        this IWritableArchive writableArchive,
+        FileInfo fileInfo,
+        WriterOptions options,
+        CancellationToken cancellationToken = default
+    )
+    {
+        using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+        await writableArchive.SaveToAsync(stream, options, cancellationToken).ConfigureAwait(false);
+    }
+
     public static void AddAllFromDirectory(
         this IWritableArchive writableArchive,
         string filePath,

src/SharpCompress/Archives/Rar/FileInfoRarArchiveVolume.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
 using SharpCompress.Common.Rar;

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -2,6 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
@@ -14,6 +16,7 @@ namespace SharpCompress.Archives.Rar;
 
 public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
 {
+    private bool _disposed;
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
         new(() => new Compressors.Rar.UnpackV2017.Unpack());
     internal Lazy<IRarUnpack> UnpackV1 { get; } = new(() => new Compressors.Rar.UnpackV1.Unpack());
@@ -25,6 +28,20 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     private RarArchive(SourceStream sourceStream)
         : base(ArchiveType.Rar, sourceStream) { }
 
+    public override void Dispose()
+    {
+        if (!_disposed)
+        {
+            if (UnpackV1.IsValueCreated && UnpackV1.Value is IDisposable unpackV1)
+            {
+                unpackV1.Dispose();
+            }
+
+            _disposed = true;
+            base.Dispose();
+        }
+    }
+
     protected override IEnumerable<RarArchiveEntry> LoadEntries(IEnumerable<RarVolume> volumes) =>
         RarArchiveEntryFactory.GetEntries(this, volumes, ReaderOptions);
 
@@ -52,6 +69,16 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
 
     protected override IReader CreateReaderForSolidExtraction()
     {
+        if (this.IsMultipartVolume())
+        {
+            var streams = Volumes.Select(volume =>
+            {
+                volume.Stream.Position = 0;
+                return volume.Stream;
+            });
+            return RarReader.Open(streams, ReaderOptions);
+        }
+
         var stream = Volumes.First().Stream;
         stream.Position = 0;
         return RarReader.Open(stream, ReaderOptions);
@@ -59,6 +86,8 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
 
     public override bool IsSolid => Volumes.First().IsSolidArchive;
 
+    public override bool IsEncrypted => Entries.First(x => !x.IsDirectory).IsEncrypted;
+
     public virtual int MinVersion => Volumes.First().MinVersion;
     public virtual int MaxVersion => Volumes.First().MaxVersion;
 
@@ -70,7 +99,7 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     /// <param name="options"></param>
     public static RarArchive Open(string filePath, ReaderOptions? options = null)
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        filePath.NotNullOrEmpty(nameof(filePath));
         var fileInfo = new FileInfo(filePath);
         return new RarArchive(
             new SourceStream(
@@ -88,7 +117,7 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     /// <param name="options"></param>
     public static RarArchive Open(FileInfo fileInfo, ReaderOptions? options = null)
     {
-        fileInfo.CheckNotNull(nameof(fileInfo));
+        fileInfo.NotNull(nameof(fileInfo));
         return new RarArchive(
             new SourceStream(
                 fileInfo,
@@ -105,7 +134,13 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     /// <param name="options"></param>
     public static RarArchive Open(Stream stream, ReaderOptions? options = null)
     {
-        stream.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
         return new RarArchive(new SourceStream(stream, _ => null, options ?? new ReaderOptions()));
     }
 
@@ -119,7 +154,7 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
         ReaderOptions? readerOptions = null
     )
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var files = fileInfos.ToArray();
         return new RarArchive(
             new SourceStream(
@@ -137,7 +172,7 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     /// <param name="readerOptions"></param>
     public static RarArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var strms = streams.ToArray();
         return new RarArchive(
             new SourceStream(
@@ -148,6 +183,70 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
         );
     }
 
+    /// <summary>
+    /// Opens a RarArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(stream, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfo, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(streams, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a RarArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfos, readerOptions)).ConfigureAwait(false);
+    }
+
     public static bool IsRarFile(string filePath) => IsRarFile(new FileInfo(filePath));
 
     public static bool IsRarFile(FileInfo fileInfo)

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

@@ -2,6 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
@@ -42,7 +44,7 @@ public class RarArchiveEntry : RarEntry, IArchiveEntry
         {
             CheckIncomplete();
             return BitConverter.ToUInt32(
-                parts.Select(fp => fp.FileHeader).Single(fh => !fh.IsSplitAfter).FileCrc,
+                parts.Select(fp => fp.FileHeader).Single(fh => !fh.IsSplitAfter).FileCrc.NotNull(),
                 0
             );
         }
@@ -68,20 +70,50 @@ public class RarArchiveEntry : RarEntry, IArchiveEntry
 
     public Stream OpenEntryStream()
     {
+        RarStream stream;
         if (IsRarV3)
         {
-            return new RarStream(
+            stream = new RarStream(
                 archive.UnpackV1.Value,
                 FileHeader,
-                new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive)
+                new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>())
+            );
+        }
+        else
+        {
+            stream = new RarStream(
+                archive.UnpackV2017.Value,
+                FileHeader,
+                new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>())
             );
         }
 
-        return new RarStream(
-            archive.UnpackV2017.Value,
-            FileHeader,
-            new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive)
-        );
+        stream.Initialize();
+        return stream;
+    }
+
+    public async Task<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

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -2,6 +2,8 @@ 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.SevenZip;
 using SharpCompress.Compressors.LZMA.Utilites;
@@ -21,7 +23,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
     /// <param name="readerOptions"></param>
     public static SevenZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
     {
-        filePath.CheckNotNullOrEmpty("filePath");
+        filePath.NotNullOrEmpty("filePath");
         return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
@@ -32,7 +34,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
     /// <param name="readerOptions"></param>
     public static SevenZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
     {
-        fileInfo.CheckNotNull("fileInfo");
+        fileInfo.NotNull("fileInfo");
         return new SevenZipArchive(
             new SourceStream(
                 fileInfo,
@@ -52,7 +54,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
         ReaderOptions? readerOptions = null
     )
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var files = fileInfos.ToArray();
         return new SevenZipArchive(
             new SourceStream(
@@ -73,7 +75,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
         ReaderOptions? readerOptions = null
     )
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var strms = streams.ToArray();
         return new SevenZipArchive(
             new SourceStream(
@@ -91,12 +93,82 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
     /// <param name="readerOptions"></param>
     public static SevenZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
-        stream.CheckNotNull("stream");
+        stream.NotNull("stream");
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
         return new SevenZipArchive(
             new SourceStream(stream, _ => null, readerOptions ?? new ReaderOptions())
         );
     }
 
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(stream, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfo, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(streams, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a SevenZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfos, readerOptions)).ConfigureAwait(false);
+    }
+
     /// <summary>
     /// Constructor with a SourceStream able to handle FileInfo and Streams.
     /// </summary>
@@ -163,7 +235,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
         {
             stream.Position = 0;
             var reader = new ArchiveReader();
-            reader.Open(stream);
+            reader.Open(stream, lookForHeader: ReaderOptions.LookForHeader);
             _database = reader.ReadDatabase(new PasswordProvider(ReaderOptions.Password));
         }
     }
@@ -194,7 +266,12 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
         new SevenZipReader(ReaderOptions, this);
 
     public override bool IsSolid =>
-        Entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder).Count() > 1;
+        Entries
+            .Where(x => !x.IsDirectory)
+            .GroupBy(x => x.FilePart.Folder)
+            .Any(folder => folder.Count() > 1);
+
+    public override bool IsEncrypted => Entries.First(x => !x.IsDirectory).IsEncrypted;
 
     public override long TotalSize =>
         _database?._packSizes.Aggregate(0L, (total, packSize) => total + packSize) ?? 0;
@@ -202,9 +279,7 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
     private sealed class SevenZipReader : AbstractReader<SevenZipEntry, SevenZipVolume>
     {
         private readonly SevenZipArchive _archive;
-        private CFolder? _currentFolder;
-        private Stream? _currentStream;
-        private CFileItem? _currentItem;
+        private SevenZipEntry? _currentEntry;
 
         internal SevenZipReader(ReaderOptions readerOptions, SevenZipArchive archive)
             : base(readerOptions, ArchiveType.SevenZip) => this._archive = archive;
@@ -217,40 +292,135 @@ public class SevenZipArchive : AbstractArchive<SevenZipArchiveEntry, SevenZipVol
             stream.Position = 0;
             foreach (var dir in entries.Where(x => x.IsDirectory))
             {
+                _currentEntry = dir;
                 yield return dir;
             }
-            foreach (
-                var group in entries.Where(x => !x.IsDirectory).GroupBy(x => x.FilePart.Folder)
-            )
+            // For non-directory entries, yield them without creating shared streams
+            // Each call to GetEntryStream() will create a fresh decompression stream
+            // to avoid state corruption issues with async operations
+            foreach (var entry in entries.Where(x => !x.IsDirectory))
             {
-                _currentFolder = group.Key;
-                if (group.Key is null)
-                {
-                    _currentStream = Stream.Null;
-                }
-                else
-                {
-                    _currentStream = _archive._database?.GetFolderStream(
-                        stream,
-                        _currentFolder,
-                        new PasswordProvider(Options.Password)
-                    );
-                }
-                foreach (var entry in group)
-                {
-                    _currentItem = entry.FilePart.Header;
-                    yield return entry;
-                }
+                _currentEntry = entry;
+                yield return entry;
             }
         }
 
-        protected override EntryStream GetEntryStream() =>
-            CreateEntryStream(
-                new ReadOnlySubStream(
-                    _currentStream.NotNull("currentStream is not null"),
-                    _currentItem?.Size ?? 0
-                )
-            );
+        protected override EntryStream GetEntryStream()
+        {
+            // Create a fresh decompression stream for each file (no state sharing).
+            // However, the LZMA decoder has bugs in its async implementation that cause
+            // state corruption even on fresh streams. The SyncOnlyStream wrapper
+            // works around these bugs by forcing async operations to use sync equivalents.
+            //
+            // TODO: Fix the LZMA decoder async bugs (in LzmaStream, Decoder, OutWindow)
+            // so this wrapper is no longer necessary.
+            var entry = _currentEntry.NotNull("currentEntry is not null");
+            if (entry.IsDirectory)
+            {
+                return CreateEntryStream(Stream.Null);
+            }
+            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;
+
+        public SyncOnlyStream(Stream baseStream) => _baseStream = baseStream;
+
+        public override bool CanRead => _baseStream.CanRead;
+        public override bool CanSeek => _baseStream.CanSeek;
+        public override bool CanWrite => _baseStream.CanWrite;
+        public override long Length => _baseStream.Length;
+        public override long Position
+        {
+            get => _baseStream.Position;
+            set => _baseStream.Position = value;
+        }
+
+        public override void Flush() => _baseStream.Flush();
+
+        public override int Read(byte[] buffer, int offset, int count) =>
+            _baseStream.Read(buffer, offset, count);
+
+        public override long Seek(long offset, SeekOrigin origin) =>
+            _baseStream.Seek(offset, origin);
+
+        public override void SetLength(long value) => _baseStream.SetLength(value);
+
+        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,
+            int count,
+            CancellationToken cancellationToken
+        )
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            return Task.FromResult(_baseStream.Read(buffer, offset, count));
+        }
+
+        public override Task WriteAsync(
+            byte[] buffer,
+            int offset,
+            int count,
+            CancellationToken cancellationToken
+        )
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            _baseStream.Write(buffer, offset, count);
+            return Task.CompletedTask;
+        }
+
+        public override Task FlushAsync(CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            _baseStream.Flush();
+            return Task.CompletedTask;
+        }
+
+#if !NETFRAMEWORK && !NETSTANDARD2_0
+        public override ValueTask<int> ReadAsync(
+            Memory<byte> buffer,
+            CancellationToken cancellationToken = default
+        )
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            return new ValueTask<int>(_baseStream.Read(buffer.Span));
+        }
+
+        public override ValueTask WriteAsync(
+            ReadOnlyMemory<byte> buffer,
+            CancellationToken cancellationToken = default
+        )
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            _baseStream.Write(buffer.Span);
+            return ValueTask.CompletedTask;
+        }
+#endif
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                _baseStream.Dispose();
+            }
+            base.Dispose(disposing);
+        }
     }
 
     private class PasswordProvider : IPasswordProvider

src/SharpCompress/Archives/SevenZip/SevenZipArchiveEntry.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.SevenZip;
 
 namespace SharpCompress.Archives.SevenZip;
@@ -10,6 +12,9 @@ public class SevenZipArchiveEntry : SevenZipEntry, IArchiveEntry
 
     public Stream OpenEntryStream() => FilePart.GetCompressedStream();
 
+    public Task<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default) =>
+        Task.FromResult(OpenEntryStream());
+
     public IArchive Archive { get; }
 
     public bool IsComplete => true;

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -2,6 +2,8 @@ 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.Tar;
 using SharpCompress.Common.Tar.Headers;
@@ -22,7 +24,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
     /// <param name="readerOptions"></param>
     public static TarArchive Open(string filePath, ReaderOptions? readerOptions = null)
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        filePath.NotNullOrEmpty(nameof(filePath));
         return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
@@ -33,7 +35,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
     /// <param name="readerOptions"></param>
     public static TarArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
     {
-        fileInfo.CheckNotNull(nameof(fileInfo));
+        fileInfo.NotNull(nameof(fileInfo));
         return new TarArchive(
             new SourceStream(
                 fileInfo,
@@ -53,7 +55,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
         ReaderOptions? readerOptions = null
     )
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var files = fileInfos.ToArray();
         return new TarArchive(
             new SourceStream(
@@ -71,7 +73,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
     /// <param name="readerOptions"></param>
     public static TarArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var strms = streams.ToArray();
         return new TarArchive(
             new SourceStream(
@@ -89,12 +91,82 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
     /// <param name="readerOptions"></param>
     public static TarArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
-        stream.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
         return new TarArchive(
             new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
         );
     }
 
+    /// <summary>
+    /// Opens a TarArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(stream, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfo, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(streams, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a TarArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfos, readerOptions)).ConfigureAwait(false);
+    }
+
     public static bool IsTarFile(string filePath) => IsTarFile(new FileInfo(filePath));
 
     public static bool IsTarFile(FileInfo fileInfo)
@@ -172,7 +244,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
                         using (var entryStream = entry.OpenEntryStream())
                         {
                             using var memoryStream = new MemoryStream();
-                            entryStream.TransferTo(memoryStream);
+                            entryStream.CopyTo(memoryStream);
                             memoryStream.Position = 0;
                             var bytes = memoryStream.ToArray();
 
@@ -216,6 +288,11 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
             closeStream
         );
 
+    protected override TarArchiveEntry CreateDirectoryEntry(
+        string directoryPath,
+        DateTime? modified
+    ) => new TarWritableArchiveEntry(this, directoryPath, modified);
+
     protected override void SaveTo(
         Stream stream,
         WriterOptions options,
@@ -224,15 +301,62 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
     )
     {
         using var writer = new TarWriter(stream, new TarWriterOptions(options));
-        foreach (var entry in oldEntries.Concat(newEntries).Where(x => !x.IsDirectory))
+        foreach (var entry in oldEntries.Concat(newEntries))
         {
-            using var entryStream = entry.OpenEntryStream();
-            writer.Write(
-                entry.Key.NotNull("Entry Key is null"),
-                entryStream,
-                entry.LastModifiedTime,
-                entry.Size
-            );
+            if (entry.IsDirectory)
+            {
+                writer.WriteDirectory(
+                    entry.Key.NotNull("Entry Key is null"),
+                    entry.LastModifiedTime
+                );
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                writer.Write(
+                    entry.Key.NotNull("Entry Key is null"),
+                    entryStream,
+                    entry.LastModifiedTime,
+                    entry.Size
+                );
+            }
+        }
+    }
+
+    protected override async Task 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);
+            }
         }
     }
 

src/SharpCompress/Archives/Tar/TarArchiveEntry.cs

@@ -1,5 +1,7 @@
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Tar;
 
@@ -10,7 +12,11 @@ public class TarArchiveEntry : TarEntry, IArchiveEntry
     internal TarArchiveEntry(TarArchive archive, TarFilePart? part, CompressionType compressionType)
         : base(part, compressionType) => Archive = archive;
 
-    public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream();
+    public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream().NotNull();
+
+    public virtual Task<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    ) => Task.FromResult(OpenEntryStream());
 
     #region IArchiveEntry Members
 

src/SharpCompress/Archives/Tar/TarWritableArchiveEntry.cs

@@ -9,7 +9,8 @@ namespace SharpCompress.Archives.Tar;
 internal sealed class TarWritableArchiveEntry : TarArchiveEntry, IWritableArchiveEntry
 {
     private readonly bool closeStream;
-    private readonly Stream stream;
+    private readonly Stream? stream;
+    private readonly bool isDirectory;
 
     internal TarWritableArchiveEntry(
         TarArchive archive,
@@ -27,6 +28,22 @@ internal sealed class TarWritableArchiveEntry : TarArchiveEntry, IWritableArchiv
         Size = size;
         LastModifiedTime = lastModified;
         this.closeStream = closeStream;
+        isDirectory = false;
+    }
+
+    internal TarWritableArchiveEntry(
+        TarArchive archive,
+        string directoryPath,
+        DateTime? lastModified
+    )
+        : base(archive, null, CompressionType.None)
+    {
+        stream = null;
+        Key = directoryPath;
+        Size = 0;
+        LastModifiedTime = lastModified;
+        closeStream = false;
+        isDirectory = true;
     }
 
     public override long Crc => 0;
@@ -47,23 +64,27 @@ internal sealed class TarWritableArchiveEntry : TarArchiveEntry, IWritableArchiv
 
     public override bool IsEncrypted => false;
 
-    public override bool IsDirectory => false;
+    public override bool IsDirectory => isDirectory;
 
     public override bool IsSplitAfter => false;
 
     internal override IEnumerable<FilePart> Parts => throw new NotImplementedException();
-    Stream IWritableArchiveEntry.Stream => stream;
+    Stream IWritableArchiveEntry.Stream => stream ?? Stream.Null;
 
     public override Stream OpenEntryStream()
     {
+        if (stream is null)
+        {
+            return Stream.Null;
+        }
         //ensure new stream is at the start, this could be reset
         stream.Seek(0, SeekOrigin.Begin);
-        return NonDisposingStream.Create(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()
     {
-        if (closeStream)
+        if (closeStream && stream is not null)
         {
             stream.Dispose();
         }

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -2,6 +2,8 @@ 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;
@@ -43,7 +45,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     /// <param name="readerOptions"></param>
     public static ZipArchive Open(string filePath, ReaderOptions? readerOptions = null)
     {
-        filePath.CheckNotNullOrEmpty(nameof(filePath));
+        filePath.NotNullOrEmpty(nameof(filePath));
         return Open(new FileInfo(filePath), readerOptions ?? new ReaderOptions());
     }
 
@@ -54,7 +56,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     /// <param name="readerOptions"></param>
     public static ZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
     {
-        fileInfo.CheckNotNull(nameof(fileInfo));
+        fileInfo.NotNull(nameof(fileInfo));
         return new ZipArchive(
             new SourceStream(
                 fileInfo,
@@ -74,7 +76,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         ReaderOptions? readerOptions = null
     )
     {
-        fileInfos.CheckNotNull(nameof(fileInfos));
+        fileInfos.NotNull(nameof(fileInfos));
         var files = fileInfos.ToArray();
         return new ZipArchive(
             new SourceStream(
@@ -92,7 +94,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     /// <param name="readerOptions"></param>
     public static ZipArchive Open(IEnumerable<Stream> streams, ReaderOptions? readerOptions = null)
     {
-        streams.CheckNotNull(nameof(streams));
+        streams.NotNull(nameof(streams));
         var strms = streams.ToArray();
         return new ZipArchive(
             new SourceStream(
@@ -110,30 +112,116 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     /// <param name="readerOptions"></param>
     public static ZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
     {
-        stream.CheckNotNull(nameof(stream));
+        stream.NotNull(nameof(stream));
+
+        if (stream is not { CanSeek: true })
+        {
+            throw new ArgumentException("Stream must be seekable", nameof(stream));
+        }
+
         return new ZipArchive(
             new SourceStream(stream, i => null, readerOptions ?? new ReaderOptions())
         );
     }
 
-    public static bool IsZipFile(string filePath, string? password = null) =>
-        IsZipFile(new FileInfo(filePath), password);
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from a stream.
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        Stream stream,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(stream, readerOptions)).ConfigureAwait(false);
+    }
 
-    public static bool IsZipFile(FileInfo fileInfo, string? password = null)
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from a FileInfo.
+    /// </summary>
+    /// <param name="fileInfo"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        FileInfo fileInfo,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfo, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from multiple streams.
+    /// </summary>
+    /// <param name="streams"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<Stream> streams,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(streams, readerOptions)).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Opens a ZipArchive asynchronously from multiple FileInfo objects.
+    /// </summary>
+    /// <param name="fileInfos"></param>
+    /// <param name="readerOptions"></param>
+    /// <param name="cancellationToken"></param>
+    public static async Task<IArchive> OpenAsync(
+        IReadOnlyList<FileInfo> fileInfos,
+        ReaderOptions? readerOptions = null,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return await Task.FromResult(Open(fileInfos, readerOptions)).ConfigureAwait(false);
+    }
+
+    public static bool IsZipFile(
+        string filePath,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    ) => IsZipFile(new FileInfo(filePath), password, bufferSize);
+
+    public static bool IsZipFile(
+        FileInfo fileInfo,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize
+    )
     {
         if (!fileInfo.Exists)
         {
             return false;
         }
         using Stream stream = fileInfo.OpenRead();
-        return IsZipFile(stream, password);
+        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);
@@ -153,11 +241,20 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         }
     }
 
-    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);
@@ -166,7 +263,93 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
                 if (stream.CanSeek) //could be multipart. Test for central directory - might not be z64 safe
                 {
                     var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
-                    var x = z.ReadSeekableHeader(stream).FirstOrDefault();
+                    var x = z.ReadSeekableHeader(stream, useSync: true).FirstOrDefault();
+                    return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    public static async Task<bool> IsZipFileAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = headerFactory
+                .ReadStreamHeader(stream)
+                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+            if (header is null)
+            {
+                return false;
+            }
+            return Enum.IsDefined(typeof(ZipHeaderType), header.ZipHeaderType);
+        }
+        catch (CryptographicException)
+        {
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    public static async Task<bool> IsZipMultiAsync(
+        Stream stream,
+        string? password = null,
+        int bufferSize = ReaderOptions.DefaultBufferSize,
+        CancellationToken cancellationToken = default
+    )
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        var headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding(), null);
+        try
+        {
+            if (stream is not SharpCompressStream)
+            {
+                stream = new SharpCompressStream(stream, bufferSize: bufferSize);
+            }
+
+            var header = headerFactory
+                .ReadStreamHeader(stream)
+                .FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+            if (header is null)
+            {
+                if (stream.CanSeek) //could be multipart. Test for central directory - might not be z64 safe
+                {
+                    var z = new SeekableZipHeaderFactory(password, new ArchiveEncoding());
+                    ZipHeader? x = null;
+                    await foreach (
+                        var h in z.ReadSeekableHeader(stream).WithCancellation(cancellationToken)
+                    )
+                    {
+                        x = h;
+                        break;
+                    }
                     return x?.ZipHeaderType == ZipHeaderType.DirectoryEntry;
                 }
                 else
@@ -196,7 +379,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         if (streams.Count() > 1) //test part 2 - true = multipart not split
         {
             streams[1].Position += 4; //skip the POST_DATA_DESCRIPTOR to prevent an exception
-            var isZip = IsZipFile(streams[1], ReaderOptions.Password);
+            var isZip = IsZipFile(streams[1], ReaderOptions.Password, ReaderOptions.BufferSize);
             streams[1].Position -= 4;
             if (isZip)
             {
@@ -221,7 +404,9 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     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)
             {
@@ -275,14 +460,59 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
     )
     {
         using var writer = new ZipWriter(stream, new ZipWriterOptions(options));
-        foreach (var entry in oldEntries.Concat(newEntries).Where(x => !x.IsDirectory))
+        foreach (var entry in oldEntries.Concat(newEntries))
         {
-            using var entryStream = entry.OpenEntryStream();
-            writer.Write(
-                entry.Key.NotNull("Entry Key is null"),
-                entryStream,
-                entry.LastModifiedTime
-            );
+            if (entry.IsDirectory)
+            {
+                writer.WriteDirectory(
+                    entry.Key.NotNull("Entry Key is null"),
+                    entry.LastModifiedTime
+                );
+            }
+            else
+            {
+                using var entryStream = entry.OpenEntryStream();
+                writer.Write(
+                    entry.Key.NotNull("Entry Key is null"),
+                    entryStream,
+                    entry.LastModifiedTime
+                );
+            }
+        }
+    }
+
+    protected override async Task 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);
+            }
         }
     }
 
@@ -294,12 +524,17 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         bool closeStream
     ) => new ZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream);
 
+    protected override ZipArchiveEntry CreateDirectoryEntry(
+        string directoryPath,
+        DateTime? modified
+    ) => new ZipWritableArchiveEntry(this, directoryPath, modified);
+
     public static ZipArchive Create() => new();
 
     protected override IReader CreateReaderForSolidExtraction()
     {
         var stream = Volumes.Single().Stream;
-        stream.Position = 0;
+        ((IStreamStack)stream).StackSeek(0);
         return ZipReader.Open(stream, ReaderOptions, Entries);
     }
 }

src/SharpCompress/Archives/Zip/ZipArchiveEntry.cs

@@ -1,5 +1,7 @@
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip;
 
 namespace SharpCompress.Archives.Zip;
@@ -9,7 +11,11 @@ public class ZipArchiveEntry : ZipEntry, IArchiveEntry
     internal ZipArchiveEntry(ZipArchive archive, SeekableZipFilePart? part)
         : base(part) => Archive = archive;
 
-    public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream();
+    public virtual Stream OpenEntryStream() => Parts.Single().GetCompressedStream().NotNull();
+
+    public virtual Task<Stream> OpenEntryStreamAsync(
+        CancellationToken cancellationToken = default
+    ) => Task.FromResult(OpenEntryStream());
 
     #region IArchiveEntry Members
 
@@ -18,6 +24,4 @@ public class ZipArchiveEntry : ZipEntry, IArchiveEntry
     public bool IsComplete => true;
 
     #endregion
-
-    public string? Comment => ((SeekableZipFilePart)Parts.Single()).Comment;
 }

src/SharpCompress/Archives/Zip/ZipWritableArchiveEntry.cs

@@ -9,7 +9,8 @@ namespace SharpCompress.Archives.Zip;
 internal class ZipWritableArchiveEntry : ZipArchiveEntry, IWritableArchiveEntry
 {
     private readonly bool closeStream;
-    private readonly Stream stream;
+    private readonly Stream? stream;
+    private readonly bool isDirectory;
     private bool isDisposed;
 
     internal ZipWritableArchiveEntry(
@@ -27,6 +28,22 @@ internal class ZipWritableArchiveEntry : ZipArchiveEntry, IWritableArchiveEntry
         Size = size;
         LastModifiedTime = lastModified;
         this.closeStream = closeStream;
+        isDirectory = false;
+    }
+
+    internal ZipWritableArchiveEntry(
+        ZipArchive archive,
+        string directoryPath,
+        DateTime? lastModified
+    )
+        : base(archive, null)
+    {
+        stream = null;
+        Key = directoryPath;
+        Size = 0;
+        LastModifiedTime = lastModified;
+        closeStream = false;
+        isDirectory = true;
     }
 
     public override long Crc => 0;
@@ -47,24 +64,28 @@ internal class ZipWritableArchiveEntry : ZipArchiveEntry, IWritableArchiveEntry
 
     public override bool IsEncrypted => false;
 
-    public override bool IsDirectory => false;
+    public override bool IsDirectory => isDirectory;
 
     public override bool IsSplitAfter => false;
 
     internal override IEnumerable<FilePart> Parts => throw new NotImplementedException();
 
-    Stream IWritableArchiveEntry.Stream => stream;
+    Stream IWritableArchiveEntry.Stream => stream ?? Stream.Null;
 
     public override Stream OpenEntryStream()
     {
+        if (stream is null)
+        {
+            return Stream.Null;
+        }
         //ensure new stream is at the start, this could be reset
         stream.Seek(0, SeekOrigin.Begin);
-        return NonDisposingStream.Create(stream);
+        return SharpCompressStream.Create(stream, leaveOpen: true);
     }
 
     internal override void Close()
     {
-        if (closeStream && !isDisposed)
+        if (closeStream && !isDisposed && stream is not null)
         {
             stream.Dispose();
             isDisposed = true;

src/SharpCompress/AssemblyInfo.cs

@@ -1,3 +1,8 @@
 using System;
+using System.Runtime.CompilerServices;
 
-[assembly: CLSCompliant(true)]
+// CLSCompliant(false) is required because ZStandard integration uses unsafe code
+[assembly: CLSCompliant(false)]
+[assembly: InternalsVisibleTo(
+    "SharpCompress.Test,PublicKey=0024000004800000940000000602000000240000525341310004000001000100158bebf1433f76dffc356733c138babea7a47536c65ed8009b16372c6f4edbb20554db74a62687f56b97c20a6ce8c4b123280279e33c894e7b3aa93ab3c573656fde4db576cfe07dba09619ead26375b25d2c4a8e43f7be257d712b0dd2eb546f67adb09281338618a58ac834fc038dd7e2740a7ab3591826252e4f4516306dc"
+)]

src/SharpCompress/BufferPool.cs

@@ -1,33 +0,0 @@
-using System.Buffers;
-
-namespace SharpCompress;
-
-internal static class BufferPool
-{
-    /// <summary>
-    ///     gets a buffer from the pool
-    /// </summary>
-    /// <param name="bufferSize">size of the buffer</param>
-    /// <returns>the buffer</returns>
-    public static byte[] Rent(int bufferSize)
-    {
-#if NETCOREAPP || NETSTANDARD2_1_OR_GREATER
-        return ArrayPool<byte>.Shared.Rent(bufferSize);
-#else
-        return new byte[bufferSize];
-#endif
-    }
-
-    /// <summary>
-    ///     returns a buffer to the pool
-    /// </summary>
-    /// <param name="buffer">the buffer to return</param>
-    public static void Return(byte[] buffer)
-    {
-#if NETCOREAPP || NETSTANDARD2_1_OR_GREATER
-        ArrayPool<byte>.Shared.Return(buffer);
-#else
-        // no-op
-#endif
-    }
-}

src/SharpCompress/Common/Arc/ArcEntry.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.GZip;
+using SharpCompress.Common.Tar;
+
+namespace SharpCompress.Common.Arc
+{
+    public class ArcEntry : Entry
+    {
+        private readonly ArcFilePart? _filePart;
+
+        internal ArcEntry(ArcFilePart? filePart)
+        {
+            _filePart = filePart;
+        }
+
+        public override long Crc
+        {
+            get
+            {
+                if (_filePart == null)
+                {
+                    return 0;
+                }
+                return _filePart.Header.Crc16;
+            }
+        }
+
+        public override string? Key => _filePart?.Header.Name;
+
+        public override string? LinkTarget => null;
+
+        public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
+
+        public override CompressionType CompressionType =>
+            _filePart?.Header.CompressionMethod ?? CompressionType.Unknown;
+
+        public override long Size => throw new NotImplementedException();
+
+        public override DateTime? LastModifiedTime => null;
+
+        public override DateTime? CreatedTime => null;
+
+        public override DateTime? LastAccessedTime => null;
+
+        public override DateTime? ArchivedTime => null;
+
+        public override bool IsEncrypted => false;
+
+        public override bool IsDirectory => false;
+
+        public override bool IsSplitAfter => false;
+
+        internal override IEnumerable<FilePart> Parts => _filePart.Empty();
+    }
+}

src/SharpCompress/Common/Arc/ArcEntryHeader.cs

@@ -0,0 +1,76 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace SharpCompress.Common.Arc
+{
+    public class ArcEntryHeader
+    {
+        public ArchiveEncoding 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(ArchiveEncoding archiveEncoding)
+        {
+            this.ArchiveEncoding = archiveEncoding;
+        }
+
+        public ArcEntryHeader? ReadHeader(Stream stream)
+        {
+            byte[] headerBytes = new byte[29];
+            if (stream.Read(headerBytes, 0, headerBytes.Length) != headerBytes.Length)
+            {
+                return null;
+            }
+            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
+            {
+                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.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.GZip;
+using SharpCompress.Common.Tar;
+using SharpCompress.Common.Tar.Headers;
+using SharpCompress.Common.Zip.Headers;
+using SharpCompress.Compressors.Lzw;
+using SharpCompress.Compressors.RLE90;
+using SharpCompress.Compressors.Squeezed;
+using SharpCompress.IO;
+
+namespace SharpCompress.Common.Arc
+{
+    public class ArcFilePart : FilePart
+    {
+        private readonly Stream? _stream;
+
+        internal ArcFilePart(ArcEntryHeader localArcHeader, Stream? seekableStream)
+            : base(localArcHeader.ArchiveEncoding)
+        {
+            _stream = seekableStream;
+            Header = localArcHeader;
+        }
+
+        internal ArcEntryHeader Header { get; set; }
+
+        internal override string? FilePartName => Header.Name;
+
+        internal override Stream GetCompressedStream()
+        {
+            if (_stream != null)
+            {
+                Stream compressedStream;
+                switch (Header.CompressionMethod)
+                {
+                    case CompressionType.None:
+                        compressedStream = new ReadOnlySubStream(
+                            _stream,
+                            Header.DataStartPosition,
+                            Header.CompressedSize
+                        );
+                        break;
+                    case CompressionType.Packed:
+                        compressedStream = new RunLength90Stream(
+                            _stream,
+                            (int)Header.CompressedSize
+                        );
+                        break;
+                    case CompressionType.Squeezed:
+                        compressedStream = new SqueezeStream(_stream, (int)Header.CompressedSize);
+                        break;
+                    case CompressionType.Crunched:
+                        if (Header.OriginalSize > 128 * 1024)
+                        {
+                            throw new NotSupportedException(
+                                "CompressionMethod: "
+                                    + Header.CompressionMethod
+                                    + " with size > 128KB"
+                            );
+                        }
+                        compressedStream = new ArcLzwStream(
+                            _stream,
+                            (int)Header.CompressedSize,
+                            true
+                        );
+                        break;
+                    default:
+                        throw new NotSupportedException(
+                            "CompressionMethod: " + Header.CompressionMethod
+                        );
+                }
+                return compressedStream;
+            }
+            return _stream.NotNull();
+        }
+
+        internal override Stream? GetRawStream() => _stream;
+    }
+}

src/SharpCompress/Common/Arc/ArcVolume.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Readers;
+
+namespace SharpCompress.Common.Arc
+{
+    public class ArcVolume : Volume
+    {
+        public ArcVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
+            : base(stream, readerOptions, index) { }
+    }
+}

src/SharpCompress/Common/ArchiveException.cs

@@ -1,9 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class ArchiveException : Exception
-{
-    public ArchiveException(string message)
-        : base(message) { }
-}

src/SharpCompress/Common/ArchiveExtractionEventArgs.cs

@@ -1,10 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class ArchiveExtractionEventArgs<T> : EventArgs
-{
-    internal ArchiveExtractionEventArgs(T entry) => Item = entry;
-
-    public T Item { get; }
-}

src/SharpCompress/Common/ArchiveType.cs

@@ -6,5 +6,7 @@ public enum ArchiveType
     Zip,
     Tar,
     SevenZip,
-    GZip
+    GZip,
+    Arc,
+    Arj,
 }

src/SharpCompress/Common/Arj/ArjEntry.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.Arc;
+using SharpCompress.Common.Arj.Headers;
+
+namespace SharpCompress.Common.Arj
+{
+    public class ArjEntry : Entry
+    {
+        private readonly ArjFilePart _filePart;
+
+        internal ArjEntry(ArjFilePart filePart)
+        {
+            _filePart = filePart;
+        }
+
+        public override long Crc => _filePart.Header.OriginalCrc32;
+
+        public override string? Key => _filePart?.Header.Name;
+
+        public override string? LinkTarget => null;
+
+        public override long CompressedSize => _filePart?.Header.CompressedSize ?? 0;
+
+        public override CompressionType CompressionType
+        {
+            get
+            {
+                if (_filePart.Header.CompressionMethod == CompressionMethod.Stored)
+                {
+                    return CompressionType.None;
+                }
+                return CompressionType.ArjLZ77;
+            }
+        }
+
+        public override long Size => _filePart?.Header.OriginalSize ?? 0;
+
+        public override DateTime? LastModifiedTime => _filePart.Header.DateTimeModified.DateTime;
+
+        public override DateTime? CreatedTime => _filePart.Header.DateTimeCreated.DateTime;
+
+        public override DateTime? LastAccessedTime => _filePart.Header.DateTimeAccessed.DateTime;
+
+        public override DateTime? ArchivedTime => null;
+
+        public override bool IsEncrypted => false;
+
+        public override bool IsDirectory => _filePart.Header.FileType == FileType.Directory;
+
+        public override bool IsSplitAfter => false;
+
+        internal override IEnumerable<FilePart> Parts => _filePart.Empty();
+    }
+}

src/SharpCompress/Common/Arj/ArjFilePart.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.Arj.Headers;
+using SharpCompress.Compressors.Arj;
+using SharpCompress.IO;
+
+namespace SharpCompress.Common.Arj
+{
+    public class ArjFilePart : FilePart
+    {
+        private readonly Stream _stream;
+        internal ArjLocalHeader Header { get; set; }
+
+        internal ArjFilePart(ArjLocalHeader localArjHeader, Stream seekableStream)
+            : base(localArjHeader.ArchiveEncoding)
+        {
+            _stream = seekableStream;
+            Header = localArjHeader;
+        }
+
+        internal override string? FilePartName => Header.Name;
+
+        internal override Stream GetCompressedStream()
+        {
+            if (_stream != null)
+            {
+                Stream compressedStream;
+                switch (Header.CompressionMethod)
+                {
+                    case CompressionMethod.Stored:
+                        compressedStream = new ReadOnlySubStream(
+                            _stream,
+                            Header.DataStartPosition,
+                            Header.CompressedSize
+                        );
+                        break;
+                    case CompressionMethod.CompressedMost:
+                    case CompressionMethod.Compressed:
+                    case CompressionMethod.CompressedFaster:
+                        if (Header.OriginalSize > 128 * 1024)
+                        {
+                            throw new NotSupportedException(
+                                "CompressionMethod: "
+                                    + Header.CompressionMethod
+                                    + " with size > 128KB"
+                            );
+                        }
+                        compressedStream = new LhaStream<Lh7DecoderCfg>(
+                            _stream,
+                            (int)Header.OriginalSize
+                        );
+                        break;
+                    case CompressionMethod.CompressedFastest:
+                        compressedStream = new LHDecoderStream(_stream, (int)Header.OriginalSize);
+                        break;
+                    default:
+                        throw new NotSupportedException(
+                            "CompressionMethod: " + Header.CompressionMethod
+                        );
+                }
+                return compressedStream;
+            }
+            return _stream.NotNull();
+        }
+
+        internal override Stream GetRawStream() => _stream;
+    }
+}

src/SharpCompress/Common/Arj/ArjVolume.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.Rar;
+using SharpCompress.Common.Rar.Headers;
+using SharpCompress.Readers;
+
+namespace SharpCompress.Common.Arj
+{
+    public class ArjVolume : Volume
+    {
+        public ArjVolume(Stream stream, ReaderOptions readerOptions, int index = 0)
+            : base(stream, readerOptions, index) { }
+
+        public override bool IsFirstVolume
+        {
+            get { return true; }
+        }
+
+        /// <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.cs

@@ -0,0 +1,142 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SharpCompress.Common.Zip.Headers;
+using SharpCompress.Crypto;
+
+namespace SharpCompress.Common.Arj.Headers
+{
+    public enum ArjHeaderType
+    {
+        MainHeader,
+        LocalHeader,
+    }
+
+    public abstract class ArjHeader
+    {
+        private const int FIRST_HDR_SIZE = 34;
+        private const ushort ARJ_MAGIC = 0xEA60;
+
+        public ArjHeader(ArjHeaderType type)
+        {
+            ArjHeaderType = type;
+        }
+
+        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)
+        {
+            // check for magic bytes
+            Span<byte> magic = stackalloc byte[2];
+            if (stream.Read(magic) != 2)
+            {
+                return Array.Empty<byte>();
+            }
+
+            var magicValue = (ushort)(magic[0] | magic[1] << 8);
+            if (magicValue != ARJ_MAGIC)
+            {
+                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;
+        }
+
+        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;
+        }
+    }
+}

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

@@ -0,0 +1,161 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SharpCompress.Common.Arj.Headers
+{
+    public class ArjLocalHeader : ArjHeader
+    {
+        public ArchiveEncoding ArchiveEncoding { get; }
+        public long DataStartPosition { get; protected set; }
+
+        public byte ArchiverVersionNumber { get; set; }
+        public byte MinVersionToExtract { get; set; }
+        public HostOS HostOS { get; set; }
+        public CompressionMethod CompressionMethod { get; set; }
+        public DosDateTime DateTimeModified { get; set; } = new DosDateTime(0);
+        public long CompressedSize { get; set; }
+        public long OriginalSize { get; set; }
+        public long OriginalCrc32 { get; set; }
+        public int FileSpecPosition { get; set; }
+        public int FileAccessMode { get; set; }
+        public byte FirstChapter { get; set; }
+        public byte LastChapter { get; set; }
+        public long ExtendedFilePosition { get; set; }
+        public DosDateTime DateTimeAccessed { get; set; } = new DosDateTime(0);
+        public DosDateTime DateTimeCreated { get; set; } = new DosDateTime(0);
+        public long OriginalSizeEvenForVolumes { get; set; }
+        public string Name { get; set; } = string.Empty;
+        public string Comment { get; set; } = string.Empty;
+
+        private const byte StdHdrSize = 30;
+        private const byte R9HdrSize = 46;
+
+        public ArjLocalHeader(ArchiveEncoding archiveEncoding)
+            : base(ArjHeaderType.LocalHeader)
+        {
+            ArchiveEncoding =
+                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+        }
+
+        public override ArjHeader? Read(Stream stream)
+        {
+            var body = ReadHeader(stream);
+            if (body.Length > 0)
+            {
+                ReadExtendedHeaders(stream);
+                var header = LoadFrom(body);
+                header.DataStartPosition = stream.Position;
+                return header;
+            }
+            return null;
+        }
+
+        public ArjLocalHeader LoadFrom(byte[] headerBytes)
+        {
+            int offset = 0;
+
+            int ReadInt16()
+            {
+                if (offset + 1 >= headerBytes.Length)
+                {
+                    throw new EndOfStreamException();
+                }
+                var v = headerBytes[offset] & 0xFF | (headerBytes[offset + 1] & 0xFF) << 8;
+                offset += 2;
+                return v;
+            }
+            long ReadInt32()
+            {
+                if (offset + 3 >= headerBytes.Length)
+                {
+                    throw new EndOfStreamException();
+                }
+                long v =
+                    headerBytes[offset] & 0xFF
+                    | (headerBytes[offset + 1] & 0xFF) << 8
+                    | (headerBytes[offset + 2] & 0xFF) << 16
+                    | (headerBytes[offset + 3] & 0xFF) << 24;
+                offset += 4;
+                return v;
+            }
+
+            byte headerSize = headerBytes[offset++];
+            ArchiverVersionNumber = headerBytes[offset++];
+            MinVersionToExtract = headerBytes[offset++];
+            HostOS hostOS = (HostOS)headerBytes[offset++];
+            Flags = headerBytes[offset++];
+            CompressionMethod = CompressionMethodFromByte(headerBytes[offset++]);
+            FileType = FileTypeFromByte(headerBytes[offset++]);
+
+            offset++; // Skip 1 byte
+
+            var rawTimestamp = ReadInt32();
+            DateTimeModified =
+                rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+
+            CompressedSize = ReadInt32();
+            OriginalSize = ReadInt32();
+            OriginalCrc32 = ReadInt32();
+            FileSpecPosition = ReadInt16();
+            FileAccessMode = ReadInt16();
+
+            FirstChapter = headerBytes[offset++];
+            LastChapter = headerBytes[offset++];
+
+            ExtendedFilePosition = 0;
+            OriginalSizeEvenForVolumes = 0;
+
+            if (headerSize > StdHdrSize)
+            {
+                ExtendedFilePosition = ReadInt32();
+
+                if (headerSize >= R9HdrSize)
+                {
+                    rawTimestamp = ReadInt32();
+                    DateTimeAccessed =
+                        rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+                    rawTimestamp = ReadInt32();
+                    DateTimeCreated =
+                        rawTimestamp != 0 ? new DosDateTime(rawTimestamp) : new DosDateTime(0);
+                    OriginalSizeEvenForVolumes = ReadInt32();
+                }
+            }
+
+            Name = Encoding.ASCII.GetString(
+                headerBytes,
+                offset,
+                Array.IndexOf(headerBytes, (byte)0, offset) - offset
+            );
+            offset += Name.Length + 1;
+
+            Comment = Encoding.ASCII.GetString(
+                headerBytes,
+                offset,
+                Array.IndexOf(headerBytes, (byte)0, offset) - offset
+            );
+            offset += Comment.Length + 1;
+
+            return this;
+        }
+
+        public static CompressionMethod CompressionMethodFromByte(byte value)
+        {
+            return value switch
+            {
+                0 => CompressionMethod.Stored,
+                1 => CompressionMethod.CompressedMost,
+                2 => CompressionMethod.Compressed,
+                3 => CompressionMethod.CompressedFaster,
+                4 => CompressionMethod.CompressedFastest,
+                8 => CompressionMethod.NoDataNoCrc,
+                9 => CompressionMethod.NoData,
+                _ => CompressionMethod.Unknown,
+            };
+        }
+    }
+}

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

@@ -0,0 +1,138 @@
+using System;
+using System.IO;
+using System.Text;
+using SharpCompress.Compressors.Deflate;
+using SharpCompress.Crypto;
+
+namespace SharpCompress.Common.Arj.Headers
+{
+    public class ArjMainHeader : ArjHeader
+    {
+        private const int FIRST_HDR_SIZE = 34;
+        private const ushort ARJ_MAGIC = 0xEA60;
+
+        public ArchiveEncoding ArchiveEncoding { get; }
+
+        public int ArchiverVersionNumber { get; private set; }
+        public int MinVersionToExtract { get; private set; }
+        public HostOS HostOs { get; private set; }
+        public int SecurityVersion { get; private set; }
+        public DosDateTime CreationDateTime { get; private set; } = new DosDateTime(0);
+        public long CompressedSize { get; private set; }
+        public long ArchiveSize { get; private set; }
+        public long SecurityEnvelope { get; private set; }
+        public int FileSpecPosition { get; private set; }
+        public int SecurityEnvelopeLength { get; private set; }
+        public int EncryptionVersion { get; private set; }
+        public int LastChapter { get; private set; }
+
+        public int ArjProtectionFactor { get; private set; }
+        public int Flags2 { get; private set; }
+        public string Name { get; private set; } = string.Empty;
+        public string Comment { get; private set; } = string.Empty;
+
+        public ArjMainHeader(ArchiveEncoding archiveEncoding)
+            : base(ArjHeaderType.MainHeader)
+        {
+            ArchiveEncoding =
+                archiveEncoding ?? throw new ArgumentNullException(nameof(archiveEncoding));
+        }
+
+        public override ArjHeader? Read(Stream stream)
+        {
+            var body = ReadHeader(stream);
+            ReadExtendedHeaders(stream);
+            return LoadFrom(body);
+        }
+
+        public ArjMainHeader LoadFrom(byte[] headerBytes)
+        {
+            var offset = 1;
+
+            byte ReadByte()
+            {
+                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();
+            }
+
+            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

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SharpCompress.Common.Arj.Headers
+{
+    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

@@ -0,0 +1,37 @@
+using System;
+
+namespace SharpCompress.Common.Arj.Headers
+{
+    public class DosDateTime
+    {
+        public DateTime DateTime { get; }
+
+        public DosDateTime(long dosValue)
+        {
+            // 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");
+    }
+}

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

@@ -0,0 +1,13 @@
+namespace SharpCompress.Common.Arj.Headers
+{
+    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

@@ -0,0 +1,19 @@
+namespace SharpCompress.Common.Arj.Headers
+{
+    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 +1,117 @@
+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 ReadExactAsync(_buffer, 0, 1, ct).ConfigureAwait(false);
+            return _buffer[0];
+        }
+
+        public async ValueTask<ushort> ReadUInt16Async(CancellationToken ct = default)
+        {
+            await ReadExactAsync(_buffer, 0, 2, ct).ConfigureAwait(false);
+            return BinaryPrimitives.ReadUInt16LittleEndian(_buffer);
+        }
+
+        public async ValueTask<uint> ReadUInt32Async(CancellationToken ct = default)
+        {
+            await ReadExactAsync(_buffer, 0, 4, ct).ConfigureAwait(false);
+            return BinaryPrimitives.ReadUInt32LittleEndian(_buffer);
+        }
+
+        public async ValueTask<ulong> ReadUInt64Async(CancellationToken ct = default)
+        {
+            await ReadExactAsync(_buffer, 0, 8, ct).ConfigureAwait(false);
+            return BinaryPrimitives.ReadUInt64LittleEndian(_buffer);
+        }
+
+        public async ValueTask<byte[]> ReadBytesAsync(int count, CancellationToken ct = default)
+        {
+            var result = new byte[count];
+            await ReadExactAsync(result, 0, count, ct).ConfigureAwait(false);
+            return result;
+        }
+
+        private async ValueTask ReadExactAsync(
+            byte[] destination,
+            int offset,
+            int length,
+            CancellationToken ct
+        )
+        {
+            var read = 0;
+            while (read < length)
+            {
+                var n = await _stream
+                    .ReadAsync(destination, offset + read, length - read, ct)
+                    .ConfigureAwait(false);
+                if (n == 0)
+                {
+                    throw new EndOfStreamException();
+                }
+
+                read += n;
+            }
+        }
+
+        public void Dispose()
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            _disposed = true;
+
+            // Dispose the original stream if we own it
+            if (!_leaveOpen)
+            {
+                _originalStream.Dispose();
+            }
+        }
+
+#if NET6_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/CompressedBytesReadEventArgs.cs

@@ -1,25 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public sealed class CompressedBytesReadEventArgs : EventArgs
-{
-    public CompressedBytesReadEventArgs(
-        long compressedBytesRead,
-        long currentFilePartCompressedBytesRead
-    )
-    {
-        CompressedBytesRead = compressedBytesRead;
-        CurrentFilePartCompressedBytesRead = currentFilePartCompressedBytesRead;
-    }
-
-    /// <summary>
-    /// Compressed bytes read for the current entry
-    /// </summary>
-    public long CompressedBytesRead { get; }
-
-    /// <summary>
-    /// Current file part read for Multipart files (e.g. Rar)
-    /// </summary>
-    public long CurrentFilePartCompressedBytesRead { get; }
-}

src/SharpCompress/Common/CompressionType.cs

@@ -16,5 +16,18 @@ public enum CompressionType
     Unknown,
     Deflate64,
     Shrink,
-    Lzw
+    Lzw,
+    Reduce1,
+    Reduce2,
+    Reduce3,
+    Reduce4,
+    Explode,
+    Squeezed,
+    Packed,
+    Crunched,
+    Squashed,
+    Crushed,
+    Distilled,
+    ZStandard,
+    ArjLZ77,
 }

src/SharpCompress/Common/CryptographicException.cs

@@ -1,9 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class CryptographicException : Exception
-{
-    public CryptographicException(string message)
-        : base(message) { }
-}

src/SharpCompress/Common/EntryStream.cs

@@ -1,11 +1,35 @@
 using System;
 using System.IO;
+using System.IO.Compression;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.IO;
 using SharpCompress.Readers;
 
 namespace SharpCompress.Common;
 
-public 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;
@@ -15,6 +39,9 @@ public class EntryStream : Stream
     {
         _reader = reader;
         _stream = stream;
+#if DEBUG_STREAMS
+        this.DebugConstruct(typeof(EntryStream));
+#endif
     }
 
     /// <summary>
@@ -26,21 +53,79 @@ public class EntryStream : Stream
         _completed = true;
     }
 
+    /// <summary>
+    /// Asynchronously skip the rest of the entry stream.
+    /// </summary>
+    public async Task SkipEntryAsync(CancellationToken cancellationToken = default)
+    {
+        await this.SkipAsync(cancellationToken).ConfigureAwait(false);
+        _completed = true;
+    }
+
     protected override void Dispose(bool disposing)
     {
-        if (!(_completed || _reader.Cancelled))
-        {
-            SkipEntry();
-        }
         if (_isDisposed)
         {
             return;
         }
         _isDisposed = true;
+        if (!(_completed || _reader.Cancelled))
+        {
+            SkipEntry();
+        }
+
+        //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised
+        if (_stream is IStreamStack ss)
+        {
+            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
+            {
+                deflateStream.Flush(); //Deflate over reads. Knock it back
+            }
+            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 !NETFRAMEWORK && !NETSTANDARD2_0
+    public override async ValueTask DisposeAsync()
+    {
+        if (_isDisposed)
+        {
+            return;
+        }
+        _isDisposed = true;
+        if (!(_completed || _reader.Cancelled))
+        {
+            await SkipEntryAsync().ConfigureAwait(false);
+        }
+
+        //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised
+        if (_stream is IStreamStack ss)
+        {
+            if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
+            {
+                await deflateStream.FlushAsync().ConfigureAwait(false);
+            }
+            else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
+            {
+                await lzmaStream.FlushAsync().ConfigureAwait(false);
+            }
+        }
+#if DEBUG_STREAMS
+        this.DebugDispose(typeof(EntryStream));
+#endif
+        await base.DisposeAsync().ConfigureAwait(false);
+        await _stream.DisposeAsync().ConfigureAwait(false);
+    }
+#endif
+
     public override bool CanRead => true;
 
     public override bool CanSeek => false;
@@ -49,11 +134,13 @@ public class EntryStream : Stream
 
     public override void Flush() { }
 
+    public override Task FlushAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+
     public override long Length => _stream.Length;
 
     public override long Position
     {
-        get => throw new NotSupportedException();
+        get => _stream.Position; //throw new NotSupportedException();
         set => throw new NotSupportedException();
     }
 
@@ -67,6 +154,38 @@ public 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 !NETFRAMEWORK && !NETSTANDARD2_0
+    public override async ValueTask<int> ReadAsync(
+        Memory<byte> buffer,
+        CancellationToken cancellationToken = default
+    )
+    {
+        var read = await _stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
+        if (read <= 0)
+        {
+            _completed = true;
+        }
+        return read;
+    }
+#endif
+
     public override int ReadByte()
     {
         var value = _stream.ReadByte();
@@ -83,4 +202,11 @@ public class EntryStream : Stream
 
     public override void Write(byte[] buffer, int offset, int count) =>
         throw new NotSupportedException();
+
+    public override Task WriteAsync(
+        byte[] buffer,
+        int offset,
+        int count,
+        CancellationToken cancellationToken
+    ) => throw new NotSupportedException();
 }

src/SharpCompress/Common/ExtractionException.cs

@@ -1,12 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class ExtractionException : Exception
-{
-    public ExtractionException(string message)
-        : base(message) { }
-
-    public ExtractionException(string message, Exception inner)
-        : base(message, inner) { }
-}

src/SharpCompress/Common/ExtractionMethods.cs

@@ -1,10 +1,22 @@
 using System;
 using System.IO;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common;
 
 internal static class ExtractionMethods
 {
+    /// <summary>
+    /// Gets the appropriate StringComparison for path checks based on the file system.
+    /// Windows uses case-insensitive file systems, while Unix-like systems use case-sensitive file systems.
+    /// </summary>
+    private static StringComparison PathComparison =>
+        RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+            ? StringComparison.OrdinalIgnoreCase
+            : StringComparison.Ordinal;
+
     /// <summary>
     /// Extract to specific directory, retaining filename
     /// </summary>
@@ -37,6 +49,7 @@ internal static class ExtractionMethods
         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"))
@@ -45,7 +58,7 @@ internal static class ExtractionMethods
 
             if (!Directory.Exists(destdir))
             {
-                if (!destdir.StartsWith(fullDestinationDirectoryPath, StringComparison.Ordinal))
+                if (!destdir.StartsWith(fullDestinationDirectoryPath, PathComparison))
                 {
                     throw new ExtractionException(
                         "Entry is trying to create a directory outside of the destination directory."
@@ -65,12 +78,7 @@ internal static class ExtractionMethods
         {
             destinationFileName = Path.GetFullPath(destinationFileName);
 
-            if (
-                !destinationFileName.StartsWith(
-                    fullDestinationDirectoryPath,
-                    StringComparison.Ordinal
-                )
-            )
+            if (!destinationFileName.StartsWith(fullDestinationDirectoryPath, PathComparison))
             {
                 throw new ExtractionException(
                     "Entry is trying to write a file outside of the destination directory."
@@ -115,4 +123,111 @@ internal static class ExtractionMethods
             entry.PreserveExtractionOptions(destinationFileName, options);
         }
     }
+
+    public static async Task WriteEntryToDirectoryAsync(
+        IEntry entry,
+        string destinationDirectory,
+        ExtractionOptions? options,
+        Func<string, ExtractionOptions?, CancellationToken, Task> 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 Task WriteEntryToFileAsync(
+        IEntry entry,
+        string destinationFileName,
+        ExtractionOptions? options,
+        Func<string, FileMode, CancellationToken, Task> 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/FilePart.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common;
 
@@ -11,7 +13,11 @@ public abstract class FilePart
     internal abstract string? FilePartName { get; }
     public int Index { get; set; }
 
-    internal abstract Stream GetCompressedStream();
+    internal abstract Stream? GetCompressedStream();
     internal abstract Stream? GetRawStream();
     internal bool Skipped { get; set; }
+
+    internal virtual Task<Stream?> GetCompressedStreamAsync(
+        CancellationToken cancellationToken = default
+    ) => Task.FromResult(GetCompressedStream());
 }

src/SharpCompress/Common/FilePartExtractionBeginEventArgs.cs

@@ -1,28 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public sealed class FilePartExtractionBeginEventArgs : EventArgs
-{
-    public FilePartExtractionBeginEventArgs(string name, long size, long compressedSize)
-    {
-        Name = name;
-        Size = size;
-        CompressedSize = compressedSize;
-    }
-
-    /// <summary>
-    /// File name for the part for the current entry
-    /// </summary>
-    public string Name { get; }
-
-    /// <summary>
-    /// Uncompressed size of the current entry in the part
-    /// </summary>
-    public long Size { get; }
-
-    /// <summary>
-    /// Compressed size of the current entry in the part
-    /// </summary>
-    public long CompressedSize { get; }
-}

src/SharpCompress/Common/GZip/GZipFilePart.cs

@@ -24,8 +24,14 @@ internal sealed class GZipFilePart : FilePart
             stream.Position = stream.Length - 8;
             ReadTrailer();
             stream.Position = position;
+            EntryStartPosition = position;
+        }
+        else
+        {
+            // For non-seekable streams, we can't read the trailer or track position.
+            // Set to 0 since the stream will be read sequentially from its current position.
+            EntryStartPosition = 0;
         }
-        EntryStartPosition = stream.Position;
     }
 
     internal long EntryStartPosition { get; }

src/SharpCompress/Common/IExtractionListener.cs

@@ -1,7 +0,0 @@
-namespace SharpCompress.Common;
-
-public interface IExtractionListener
-{
-    void FireFilePartExtractionBegin(string name, long size, long compressedSize);
-    void FireCompressedBytesRead(long currentPartCompressedBytes, long compressedReadBytes);
-}

src/SharpCompress/Common/IncompleteArchiveException.cs

@@ -1,7 +0,0 @@
-namespace SharpCompress.Common;
-
-public class IncompleteArchiveException : ArchiveException
-{
-    public IncompleteArchiveException(string message)
-        : base(message) { }
-}

src/SharpCompress/Common/InvalidFormatException.cs

@@ -1,12 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class InvalidFormatException : ExtractionException
-{
-    public InvalidFormatException(string message)
-        : base(message) { }
-
-    public InvalidFormatException(string message, Exception inner)
-        : base(message, inner) { }
-}

src/SharpCompress/Common/MultiVolumeExtractionException.cs

@@ -1,12 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class MultiVolumeExtractionException : ExtractionException
-{
-    public MultiVolumeExtractionException(string message)
-        : base(message) { }
-
-    public MultiVolumeExtractionException(string message, Exception inner)
-        : base(message, inner) { }
-}

src/SharpCompress/Common/MultipartStreamRequiredException.cs

@@ -1,7 +0,0 @@
-namespace SharpCompress.Common;
-
-public class MultipartStreamRequiredException : ExtractionException
-{
-    public MultipartStreamRequiredException(string message)
-        : base(message) { }
-}

src/SharpCompress/Common/ProgressReport.cs

@@ -0,0 +1,43 @@
+namespace SharpCompress.Common;
+
+/// <summary>
+/// Represents progress information for compression or extraction operations.
+/// </summary>
+public sealed class ProgressReport
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ProgressReport"/> class.
+    /// </summary>
+    /// <param name="entryPath">The path of the entry being processed.</param>
+    /// <param name="bytesTransferred">Number of bytes transferred so far.</param>
+    /// <param name="totalBytes">Total bytes to be transferred, or null if unknown.</param>
+    public ProgressReport(string entryPath, long bytesTransferred, long? totalBytes)
+    {
+        EntryPath = entryPath;
+        BytesTransferred = bytesTransferred;
+        TotalBytes = totalBytes;
+    }
+
+    /// <summary>
+    /// Gets the path of the entry being processed.
+    /// </summary>
+    public string EntryPath { get; }
+
+    /// <summary>
+    /// Gets the number of bytes transferred so far.
+    /// </summary>
+    public long BytesTransferred { get; }
+
+    /// <summary>
+    /// Gets the total number of bytes to be transferred, or null if unknown.
+    /// </summary>
+    public long? TotalBytes { get; }
+
+    /// <summary>
+    /// Gets the progress percentage (0-100), or null if total bytes is unknown.
+    /// </summary>
+    public double? PercentComplete =>
+        TotalBytes.HasValue && TotalBytes.Value > 0
+            ? (double)BytesTransferred / TotalBytes.Value * 100
+            : null;
+}

src/SharpCompress/Common/Rar/CryptKey5.cs

@@ -17,7 +17,7 @@ internal class CryptKey5 : ICryptKey
     private byte[] _pswCheck = { };
     private byte[] _hashKey = { };
 
-    public CryptKey5(string password, Rar5CryptoInfo rar5CryptoInfo)
+    public CryptKey5(string? password, Rar5CryptoInfo rar5CryptoInfo)
     {
         _password = password ?? "";
         _cryptoInfo = rar5CryptoInfo;

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

@@ -1,8 +1,5 @@
 #nullable disable
 
-using System;
-using System.Security.Cryptography;
-using SharpCompress.Common.Rar.Headers;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;

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

@@ -1,9 +1,6 @@
-#nullable disable
-
 using System;
 using System.IO;
 using System.Linq;
-using System.Security.Cryptography;
 using System.Text;
 using SharpCompress.IO;
 #if !Rar2017_64bit
@@ -18,7 +15,7 @@ namespace SharpCompress.Common.Rar.Headers;
 
 internal class FileHeader : RarHeader
 {
-    private byte[] _hash;
+    private byte[]? _hash;
 
     public FileHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
         : base(header, reader, headerType) { }
@@ -319,6 +316,10 @@ internal class FileHeader : RarHeader
 
                     if (NewSubHeaderType.SUBHEAD_TYPE_RR.Equals(fileNameBytes))
                     {
+                        if (SubData is null)
+                        {
+                            throw new InvalidFormatException();
+                        }
                         RecoverySectors =
                             SubData[8]
                             + (SubData[9] << 8)
@@ -340,12 +341,16 @@ internal class FileHeader : RarHeader
             if (RemainingHeaderBytes(reader) >= 2)
             {
                 var extendedFlags = reader.ReadUInt16();
-                FileLastModifiedTime = ProcessExtendedTimeV4(
-                    extendedFlags,
-                    FileLastModifiedTime,
-                    reader,
-                    0
-                );
+                if (FileLastModifiedTime is not null)
+                {
+                    FileLastModifiedTime = ProcessExtendedTimeV4(
+                        extendedFlags,
+                        FileLastModifiedTime,
+                        reader,
+                        0
+                    );
+                }
+
                 FileCreatedTime = ProcessExtendedTimeV4(extendedFlags, null, reader, 1);
                 FileLastAccessedTime = ProcessExtendedTimeV4(extendedFlags, null, reader, 2);
                 FileArchivedTime = ProcessExtendedTimeV4(extendedFlags, null, reader, 3);
@@ -377,7 +382,7 @@ internal class FileHeader : RarHeader
             var dosTime = reader.ReadUInt32();
             time = Utility.DosDateToDateTime(dosTime);
         }
-        if ((rmode & 4) == 0)
+        if ((rmode & 4) == 0 && time is not null)
         {
             time = time.Value.AddSeconds(1);
         }
@@ -390,7 +395,11 @@ internal class FileHeader : RarHeader
         }
 
         //10^-7 to 10^-3
-        return time.Value.AddMilliseconds(nanosecondHundreds * Math.Pow(10, -4));
+        if (time is not null)
+        {
+            return time.Value.AddMilliseconds(nanosecondHundreds * Math.Pow(10, -4));
+        }
+        return null;
     }
 
     private static string ConvertPathV4(string path)
@@ -406,13 +415,13 @@ internal class FileHeader : RarHeader
         return path;
     }
 
-    public override string ToString() => FileName;
+    public override string ToString() => FileName ?? "FileHeader";
 
     private ushort Flags { get; set; }
 
     private bool HasFlag(ushort flag) => (Flags & flag) == flag;
 
-    internal byte[] FileCrc
+    internal byte[]? FileCrc
     {
         get => _hash;
         private set => _hash = value;
@@ -441,22 +450,22 @@ internal class FileHeader : RarHeader
     public bool IsRedir => RedirType != 0;
     public byte RedirFlags { get; private set; }
     public bool IsRedirDirectory => (RedirFlags & RedirFlagV5.DIRECTORY) != 0;
-    public string RedirTargetName { get; private set; }
+    public string? RedirTargetName { get; private set; }
 
     // unused for UnpackV1 implementation (limitation)
     internal size_t WindowSize { get; private set; }
 
-    internal byte[] R4Salt { get; private set; }
-    internal Rar5CryptoInfo Rar5CryptoInfo { get; private set; }
+    internal byte[]? R4Salt { get; private set; }
+    internal Rar5CryptoInfo? Rar5CryptoInfo { get; private set; }
     private byte HostOs { get; set; }
     internal uint FileAttributes { get; private set; }
     internal long CompressedSize { get; private set; }
     internal long UncompressedSize { get; private set; }
-    internal string FileName { get; private set; }
-    internal byte[] SubData { get; private set; }
+    internal string? FileName { get; private set; }
+    internal byte[]? SubData { get; private set; }
     internal int RecoverySectors { get; private set; }
     internal long DataStartPosition { get; set; }
-    public Stream PackedStream { get; set; }
+    public Stream? PackedStream { get; set; }
 
     public bool IsSplitBefore =>
         IsRar5 ? HasHeaderFlag(HeaderFlagsV5.SPLIT_BEFORE) : HasFlag(FileFlagsV4.SPLIT_BEFORE);

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

@@ -13,7 +13,7 @@ public enum HeaderType : byte
     Sign,
     NewSub,
     EndArchive,
-    Crypt
+    Crypt,
 }
 
 internal static class HeaderCodeV

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

@@ -1,5 +1,4 @@
 using System;
-using System.IO;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
@@ -21,7 +20,7 @@ internal class RarHeader : IRarHeader
         {
             return new RarHeader(reader, isRar5, archiveEncoding);
         }
-        catch (EndOfStreamException)
+        catch (InvalidFormatException)
         {
             return null;
         }

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

@@ -1,7 +1,5 @@
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 using SharpCompress.Readers;
 
@@ -160,10 +158,15 @@ public class RarHeaderFactory
                             {
                                 fh.PackedStream = new RarCryptoWrapper(
                                     ms,
-                                    fh.R4Salt is null ? fh.Rar5CryptoInfo.Salt : fh.R4Salt,
                                     fh.R4Salt is null
-                                        ? new CryptKey5(Options.Password!, fh.Rar5CryptoInfo)
-                                        : new CryptKey3(Options.Password!)
+                                        ? fh.Rar5CryptoInfo.NotNull().Salt
+                                        : fh.R4Salt,
+                                    fh.R4Salt is null
+                                        ? new CryptKey5(
+                                            Options.Password,
+                                            fh.Rar5CryptoInfo.NotNull()
+                                        )
+                                        : new CryptKey3(Options.Password)
                                 );
                             }
                         }

src/SharpCompress/Common/Rar/RarEntry.cs

@@ -20,7 +20,7 @@ public abstract class RarEntry : Entry
     /// <summary>
     /// The File's 32 bit CRC Hash
     /// </summary>
-    public override long Crc => BitConverter.ToUInt32(FileHeader.FileCrc, 0);
+    public override long Crc => BitConverter.ToUInt32(FileHeader.FileCrc.NotNull(), 0);
 
     /// <summary>
     /// The path of the file internal to the Rar Archive.
@@ -68,7 +68,7 @@ public abstract class RarEntry : Entry
 
     public bool IsRedir => FileHeader.IsRedir;
 
-    public string RedirTargetName => FileHeader.RedirTargetName;
+    public string? RedirTargetName => FileHeader.RedirTargetName;
 
     public override string ToString() =>
         string.Format(

src/SharpCompress/Common/Rar/RarVolume.cs

@@ -61,9 +61,8 @@ public abstract class RarVolume : Volume
                         var fh = (FileHeader)header;
                         if (fh.FileName == "CMT")
                         {
-                            var part = CreateFilePart(lastMarkHeader!, fh);
                             var buffer = new byte[fh.CompressedSize];
-                            part.GetCompressedStream().Read(buffer, 0, buffer.Length);
+                            fh.PackedStream.NotNull().ReadFully(buffer);
                             Comment = Encoding.UTF8.GetString(buffer, 0, buffer.Length - 1);
                         }
                     }

src/SharpCompress/Common/ReaderCancelledException.cs

@@ -1,12 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class ReaderCancelledException : Exception
-{
-    public ReaderCancelledException(string message)
-        : base(message) { }
-
-    public ReaderCancelledException(string message, Exception inner)
-        : base(message, inner) { }
-}

src/SharpCompress/Common/ReaderExtractionEventArgs.cs

@@ -1,17 +0,0 @@
-using System;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Common;
-
-public sealed class ReaderExtractionEventArgs<T> : EventArgs
-{
-    internal ReaderExtractionEventArgs(T entry, ReaderProgress? readerProgress = null)
-    {
-        Item = entry;
-        ReaderProgress = readerProgress;
-    }
-
-    public T Item { get; }
-
-    public ReaderProgress? ReaderProgress { get; }
-}

src/SharpCompress/Common/SevenZip/ArchiveReader.cs

@@ -784,7 +784,7 @@ internal class ArchiveReader
                         );
                         break;
                     default:
-                        throw new InvalidOperationException();
+                        throw new InvalidFormatException();
                 }
             }
         }
@@ -843,7 +843,7 @@ internal class ArchiveReader
                 outStream.ReadExact(data, 0, data.Length);
                 if (outStream.ReadByte() >= 0)
                 {
-                    throw new InvalidOperationException("Decoded stream is longer than expected.");
+                    throw new InvalidFormatException("Decoded stream is longer than expected.");
                 }
                 dataVector.Add(data);
 
@@ -854,7 +854,7 @@ internal class ArchiveReader
                         != folder._unpackCrc
                     )
                     {
-                        throw new InvalidOperationException(
+                        throw new InvalidFormatException(
                             "Decoded stream does not match expected CRC."
                         );
                     }
@@ -996,6 +996,11 @@ internal class ArchiveReader
                             numFiles,
                             delegate(int i, uint? attr)
                             {
+                                // Keep the original attribute value because it could potentially get
+                                // modified in the logic that follows. Some callers of the library may
+                                // find the original value useful.
+                                db._files[i].ExtendedAttrib = attr;
+
                                 // Some third party implementations established an unofficial extension
                                 // of the 7z archive format by placing posix file attributes in the high
                                 // bits of the windows file attributes. This makes use of the fact that
@@ -1220,23 +1225,46 @@ internal class ArchiveReader
 
     #region Public Methods
 
-    public void Open(Stream stream)
+    public void Open(Stream stream, bool lookForHeader)
     {
         Close();
 
         _streamOrigin = stream.Position;
         _streamEnding = stream.Length;
 
-        // TODO: Check Signature!
-        _header = new byte[0x20];
-        for (var offset = 0; offset < 0x20; )
+        var canScan = lookForHeader ? 0x80000 - 20 : 0;
+        while (true)
         {
-            var delta = stream.Read(_header, offset, 0x20 - offset);
-            if (delta == 0)
+            // TODO: Check Signature!
+            _header = new byte[0x20];
+            for (var offset = 0; offset < 0x20; )
             {
-                throw new EndOfStreamException();
+                var delta = stream.Read(_header, offset, 0x20 - offset);
+                if (delta == 0)
+                {
+                    throw new EndOfStreamException();
+                }
+
+                offset += delta;
             }
-            offset += delta;
+
+            if (
+                !lookForHeader
+                || _header
+                    .AsSpan(0, length: 6)
+                    .SequenceEqual<byte>([0x37, 0x7A, 0xBC, 0xAF, 0x27, 0x1C])
+            )
+            {
+                break;
+            }
+
+            if (canScan == 0)
+            {
+                throw new InvalidFormatException("Unable to find 7z signature");
+            }
+
+            canScan--;
+            stream.Position = ++_streamOrigin;
         }
 
         _stream = stream;
@@ -1435,7 +1463,7 @@ internal class ArchiveReader
 #if DEBUG
             Log.WriteLine(_db._files[index].Name);
 #endif
-            if (_db._files[index].CrcDefined)
+            if (_db._files[index].Crc.HasValue)
             {
                 _stream = new CrcCheckStream(_db._files[index].Crc.Value);
             }

src/SharpCompress/Common/SevenZip/CFileItem.cs

@@ -8,18 +8,13 @@ internal class CFileItem
 {
     public long Size { get; internal set; }
     public uint? Attrib { get; internal set; }
+    public uint? ExtendedAttrib { get; internal set; }
     public uint? Crc { get; internal set; }
     public string Name { get; internal set; }
 
     public bool HasStream { get; internal set; }
     public bool IsDir { get; internal set; }
 
-    public bool CrcDefined => Crc != null;
-
-    public bool AttribDefined => Attrib != null;
-
-    public void SetAttrib(uint attrib) => Attrib = attrib;
-
     public DateTime? CTime { get; internal set; }
     public DateTime? ATime { get; internal set; }
     public DateTime? MTime { get; internal set; }

src/SharpCompress/Common/SevenZip/SevenZipEntry.cs

@@ -38,5 +38,8 @@ public class SevenZipEntry : Entry
     public override int? Attrib =>
         FilePart.Header.Attrib.HasValue ? (int?)FilePart.Header.Attrib.Value : null;
 
+    public int? ExtendedAttrib =>
+        FilePart.Header.ExtendedAttrib.HasValue ? (int?)FilePart.Header.ExtendedAttrib.Value : null;
+
     internal override IEnumerable<FilePart> Parts => FilePart.AsEnumerable<FilePart>();
 }

src/SharpCompress/Common/SevenZip/SevenZipFilePart.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using System.Linq;
 using SharpCompress.IO;
@@ -41,7 +40,7 @@ internal class SevenZipFilePart : FilePart
     {
         if (!Header.HasStream)
         {
-            throw new InvalidOperationException("File does not have a stream.");
+            return Stream.Null;
         }
         var folderStream = _database.GetFolderStream(_stream, Folder!, _database.PasswordProvider);
 
@@ -68,6 +67,7 @@ internal class SevenZipFilePart : FilePart
         }
     }
 
+    private const uint K_COPY = 0x0;
     private const uint K_LZMA2 = 0x21;
     private const uint K_LZMA = 0x030101;
     private const uint K_PPMD = 0x030401;
@@ -83,10 +83,11 @@ internal class SevenZipFilePart : FilePart
         var coder = Folder.NotNull()._coders.First();
         return coder._methodId._id switch
         {
+            K_COPY => CompressionType.None,
             K_LZMA or K_LZMA2 => CompressionType.LZMA,
             K_PPMD => CompressionType.PPMd,
             K_B_ZIP2 => CompressionType.BZip2,
-            _ => throw new NotImplementedException()
+            _ => throw new InvalidFormatException(),
         };
     }