Enabling Bzip2 but something else is broken

# Conflicts:
#	src/SharpCompress/Archives/GZip/GZipArchive.cs
#	src/SharpCompress/Common/GZip/GZipFilePart.cs
#	src/SharpCompress/Common/Tar/Headers/TarHeader.cs
#	src/SharpCompress/Common/Zip/SeekableZipHeaderFactory.cs
#	src/SharpCompress/Common/Zip/ZipFilePart.cs
#	src/SharpCompress/Compressors/Deflate/ZlibBaseStream.cs
#	src/SharpCompress/Compressors/LZMA/LZipStream.cs
#	src/SharpCompress/Compressors/Xz/BinaryUtils.cs
#	src/SharpCompress/Compressors/Xz/Crc32.cs
#	src/SharpCompress/Writers/Tar/TarWriter.cs
#	src/SharpCompress/Writers/Zip/ZipCentralDirectoryEntry.cs
#	src/SharpCompress/Writers/Zip/ZipWriter.cs

.config/dotnet-tools.json

@@ -0,0 +1,12 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "dotnet-format": {
+      "version": "4.1.131201",
+      "commands": [
+        "dotnet-format"
+      ]
+    }
+  }
+}

.github/workflows/dotnetcore.yml

@@ -12,7 +12,7 @@ jobs:
     - uses: actions/checkout@v1
     - uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 3.1.302
+        dotnet-version: 5.0.101
     - run: dotnet run -p build/build.csproj
     - uses: actions/upload-artifact@v2
       with:

README.md

@@ -1,6 +1,6 @@
 # SharpCompress
 
-SharpCompress is a compression library in pure C# for .NET Standard 2.0, 2.1 and NET 4.6 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 Standard 2.0, 2.1, .NET Core 3.1 and .NET 5.0 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.
 
 The major feature is support for non-seekable streams so large files can be processed on the fly (i.e. download stream).
 

build/Program.cs

@@ -9,10 +9,11 @@ using static SimpleExec.Command;
 class Program
 {
     private const string Clean = "clean";
+    private const string Format = "format";
     private const string Build = "build";
     private const string Test = "test";
     private const string Publish = "publish";
-    
+
     static void Main(string[] args)
     {
         Target(Clean,
@@ -39,30 +40,36 @@ class Program
                 }
             });
 
-        Target(Build, ForEach("net46", "netstandard2.0", "netstandard2.1"), 
+        Target(Format, () =>
+        {
+            Run("dotnet", "tool restore");
+            Run("dotnet", "format --check");
+        });
+
+        Target(Build, DependsOn(Format),
                framework =>
                {
-                    if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && framework == "net46")
-                    {
-                        return;
-                    }
-                    Run("dotnet", "build src/SharpCompress/SharpCompress.csproj -c Release");
-                });
+                   if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && framework == "net46")
+                   {
+                       return;
+                   }
+                   Run("dotnet", "build src/SharpCompress/SharpCompress.csproj -c Release");
+               });
 
-        Target(Test, DependsOn(Build), ForEach("netcoreapp3.1"), 
-            framework =>
-            {
-                IEnumerable<string> GetFiles(string d)
-                {
-                    return Glob.Files(".", d);
-                }
+        Target(Test, DependsOn(Build), ForEach("net5.0"),
+               framework =>
+               {
+                   IEnumerable<string> GetFiles(string d)
+                   {
+                       return Glob.Files(".", d);
+                   }
+
+                   foreach (var file in GetFiles("**/*.Test.csproj"))
+                   {
+                       Run("dotnet", $"test {file} -c Release -f {framework}");
+                   }
+               });
 
-                foreach (var file in GetFiles("**/*.Test.csproj"))
-                {
-                    Run("dotnet", $"test {file} -c Release -f {framework}");
-                }
-            });
-        
         Target(Publish, DependsOn(Test),
                () =>
                {
@@ -70,7 +77,7 @@ class Program
                });
 
         Target("default", DependsOn(Publish), () => Console.WriteLine("Done!"));
-        
+
         RunTargetsAndExit(args);
     }
 }

build/build.csproj

@@ -2,13 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Bullseye" Version="3.3.0" />
-    <PackageReference Include="Glob" Version="1.1.7" />
-    <PackageReference Include="SimpleExec" Version="6.2.0" />
+    <PackageReference Include="Bullseye" Version="3.6.0" />
+    <PackageReference Include="Glob" Version="1.1.8" />
+    <PackageReference Include="SimpleExec" Version="6.4.0" />
   </ItemGroup>
 
 </Project>

global.json

@@ -1,5 +1,5 @@
 {
   "sdk": {
-    "version": "3.1.302"
+    "version": "5.0.101"
   }
 }

src/SharpCompress/Algorithms/Alder32.cs

@@ -0,0 +1,285 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the GNU Affero General Public License, Version 3.
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+#if !NETSTANDARD2_0 && !NETSTANDARD2_1
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
+#endif
+
+namespace SharpCompress.Algorithms
+{
+    /// <summary>
+    /// Calculates the 32 bit Adler checksum of a given buffer according to
+    /// RFC 1950. ZLIB Compressed Data Format Specification version 3.3)
+    /// </summary>
+    internal static class Adler32
+    {
+        /// <summary>
+        /// The default initial seed value of a Adler32 checksum calculation.
+        /// </summary>
+        public const uint SeedValue = 1U;
+
+#if !NETSTANDARD2_0 && !NETSTANDARD2_1
+        private const int MinBufferSize = 64;
+#endif
+
+        // Largest prime smaller than 65536
+        private const uint BASE = 65521;
+
+        // NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1
+        private const uint NMAX = 5552;
+
+        /// <summary>
+        /// Calculates the Adler32 checksum with the bytes taken from the span.
+        /// </summary>
+        /// <param name="buffer">The readonly span of bytes.</param>
+        /// <returns>The <see cref="uint"/>.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static uint Calculate(ReadOnlySpan<byte> buffer)
+        {
+            return Calculate(SeedValue, buffer);
+        }
+
+        /// <summary>
+        /// Calculates the Adler32 checksum with the bytes taken from the span and seed.
+        /// </summary>
+        /// <param name="adler">The input Adler32 value.</param>
+        /// <param name="buffer">The readonly span of bytes.</param>
+        /// <returns>The <see cref="uint"/>.</returns>
+        public static uint Calculate(uint adler, ReadOnlySpan<byte> buffer)
+        {
+            if (buffer.IsEmpty)
+            {
+                return SeedValue;
+            }
+
+#if !NETSTANDARD2_0 && !NETSTANDARD2_1
+            if (Sse3.IsSupported && buffer.Length >= MinBufferSize)
+            {
+                return CalculateSse(adler, buffer);
+            }
+
+            return CalculateScalar(adler, buffer);
+#else
+            return CalculateScalar(adler, buffer);
+#endif
+        }
+
+        // Based on https://github.com/chromium/chromium/blob/master/third_party/zlib/adler32_simd.c
+#if !NETSTANDARD2_0 && !NETSTANDARD2_1
+        private static unsafe uint CalculateSse(uint adler, ReadOnlySpan<byte> buffer)
+        {
+            uint s1 = adler & 0xFFFF;
+            uint s2 = (adler >> 16) & 0xFFFF;
+
+            // Process the data in blocks.
+            const int BLOCK_SIZE = 1 << 5;
+
+            uint length = (uint)buffer.Length;
+            uint blocks = length / BLOCK_SIZE;
+            length -= blocks * BLOCK_SIZE;
+
+            int index = 0;
+            fixed (byte* bufferPtr = &buffer[0])
+            {
+                index += (int)blocks * BLOCK_SIZE;
+                var localBufferPtr = bufferPtr;
+
+                // _mm_setr_epi8 on x86
+                var tap1 = Vector128.Create(32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17);
+                var tap2 = Vector128.Create(16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1);
+                Vector128<byte> zero = Vector128<byte>.Zero;
+                var ones = Vector128.Create((short)1);
+
+                while (blocks > 0)
+                {
+                    uint n = NMAX / BLOCK_SIZE;  /* The NMAX constraint. */
+                    if (n > blocks)
+                    {
+                        n = blocks;
+                    }
+
+                    blocks -= n;
+
+                    // Process n blocks of data. At most NMAX data bytes can be
+                    // processed before s2 must be reduced modulo BASE.
+                    Vector128<int> v_ps = Vector128.CreateScalar(s1 * n).AsInt32();
+                    Vector128<int> v_s2 = Vector128.CreateScalar(s2).AsInt32();
+                    Vector128<int> v_s1 = Vector128<int>.Zero;
+
+                    do
+                    {
+                        // Load 32 input bytes.
+                        Vector128<byte> bytes1 = Sse3.LoadDquVector128(localBufferPtr);
+                        Vector128<byte> bytes2 = Sse3.LoadDquVector128(localBufferPtr + 16);
+
+                        // Add previous block byte sum to v_ps.
+                        v_ps = Sse2.Add(v_ps, v_s1);
+
+                        // Horizontally add the bytes for s1, multiply-adds the
+                        // bytes by [ 32, 31, 30, ... ] for s2.
+                        v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes1, zero).AsInt32());
+                        Vector128<short> mad1 = Ssse3.MultiplyAddAdjacent(bytes1, tap1);
+                        v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad1, ones));
+
+                        v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes2, zero).AsInt32());
+                        Vector128<short> mad2 = Ssse3.MultiplyAddAdjacent(bytes2, tap2);
+                        v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad2, ones));
+
+                        localBufferPtr += BLOCK_SIZE;
+                    }
+                    while (--n > 0);
+
+                    v_s2 = Sse2.Add(v_s2, Sse2.ShiftLeftLogical(v_ps, 5));
+
+                    // Sum epi32 ints v_s1(s2) and accumulate in s1(s2).
+                    const byte S2301 = 0b1011_0001;  // A B C D -> B A D C
+                    const byte S1032 = 0b0100_1110;  // A B C D -> C D A B
+
+                    v_s1 = Sse2.Add(v_s1, Sse2.Shuffle(v_s1, S2301));
+                    v_s1 = Sse2.Add(v_s1, Sse2.Shuffle(v_s1, S1032));
+
+                    s1 += (uint)v_s1.ToScalar();
+
+                    v_s2 = Sse2.Add(v_s2, Sse2.Shuffle(v_s2, S2301));
+                    v_s2 = Sse2.Add(v_s2, Sse2.Shuffle(v_s2, S1032));
+
+                    s2 = (uint)v_s2.ToScalar();
+
+                    // Reduce.
+                    s1 %= BASE;
+                    s2 %= BASE;
+                }
+            }
+
+            ref byte bufferRef = ref MemoryMarshal.GetReference(buffer);
+
+            if (length > 0)
+            {
+                if (length >= 16)
+                {
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    length -= 16;
+                }
+
+                while (length-- > 0)
+                {
+                    s2 += s1 += Unsafe.Add(ref bufferRef, index++);
+                }
+
+                if (s1 >= BASE)
+                {
+                    s1 -= BASE;
+                }
+
+                s2 %= BASE;
+            }
+
+            return s1 | (s2 << 16);
+        }
+#endif
+
+        private static uint CalculateScalar(uint adler, ReadOnlySpan<byte> buffer)
+        {
+            uint s1 = adler & 0xFFFF;
+            uint s2 = (adler >> 16) & 0xFFFF;
+            uint k;
+
+            ref byte bufferRef = ref MemoryMarshal.GetReference<byte>(buffer);
+            uint length = (uint)buffer.Length;
+            int index = 0;
+
+            while (length > 0)
+            {
+                k = length < NMAX ? length : NMAX;
+                length -= k;
+
+                while (k >= 16)
+                {
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    s1 += Unsafe.Add(ref bufferRef, index++);
+                    s2 += s1;
+                    k -= 16;
+                }
+
+                if (k != 0)
+                {
+                    do
+                    {
+                        s1 += Unsafe.Add(ref bufferRef, index++);
+                        s2 += s1;
+                    }
+                    while (--k != 0);
+                }
+
+                s1 %= BASE;
+                s2 %= BASE;
+            }
+
+            return (s2 << 16) | s1;
+        }
+    }
+}

src/SharpCompress/Archives/AbstractArchive.cs

@@ -2,29 +2,25 @@
 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 abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtractionListener
+    public abstract class AbstractArchive<TEntry, TVolume> : IArchive
         where TEntry : IArchiveEntry
         where TVolume : IVolume
     {
         private readonly LazyReadOnlyCollection<TVolume> lazyVolumes;
         private readonly LazyReadOnlyCollection<TEntry> lazyEntries;
 
-        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; }
+        protected ReaderOptions ReaderOptions { get; } = new ();
 
         private bool disposed;
 
-        internal AbstractArchive(ArchiveType type, FileInfo fileInfo, ReaderOptions readerOptions)
+        internal AbstractArchive(ArchiveType type, FileInfo fileInfo, ReaderOptions readerOptions, CancellationToken cancellationToken)
         {
             Type = type;
             if (!fileInfo.Exists)
@@ -33,42 +29,30 @@ namespace SharpCompress.Archives
             }
             ReaderOptions = readerOptions;
             readerOptions.LeaveStreamOpen = false;
-            lazyVolumes = new LazyReadOnlyCollection<TVolume>(LoadVolumes(fileInfo));
-            lazyEntries = new LazyReadOnlyCollection<TEntry>(LoadEntries(Volumes));
+            lazyVolumes = new LazyReadOnlyCollection<TVolume>(LoadVolumes(fileInfo, cancellationToken));
+            lazyEntries = new LazyReadOnlyCollection<TEntry>(LoadEntries(Volumes, cancellationToken));
         }
 
 
-        protected abstract IEnumerable<TVolume> LoadVolumes(FileInfo file);
+        protected abstract IAsyncEnumerable<TVolume> LoadVolumes(FileInfo file, CancellationToken cancellationToken);
 
-        internal AbstractArchive(ArchiveType type, IEnumerable<Stream> streams, ReaderOptions readerOptions)
+        internal AbstractArchive(ArchiveType type, IAsyncEnumerable<Stream> streams, ReaderOptions readerOptions, CancellationToken cancellationToken)
         {
             Type = type;
             ReaderOptions = readerOptions;
-            lazyVolumes = new LazyReadOnlyCollection<TVolume>(LoadVolumes(streams.Select(CheckStreams)));
-            lazyEntries = new LazyReadOnlyCollection<TEntry>(LoadEntries(Volumes));
+            lazyVolumes = new LazyReadOnlyCollection<TVolume>(LoadVolumes(streams.Select(CheckStreams), cancellationToken));
+            lazyEntries = new LazyReadOnlyCollection<TEntry>(LoadEntries(Volumes, cancellationToken));
         }
 
-#nullable disable
         internal AbstractArchive(ArchiveType type)
         {
             Type = type;
-            lazyVolumes = new LazyReadOnlyCollection<TVolume>(Enumerable.Empty<TVolume>());
-            lazyEntries = new LazyReadOnlyCollection<TEntry>(Enumerable.Empty<TEntry>());
+            lazyVolumes = new LazyReadOnlyCollection<TVolume>( AsyncEnumerable.Empty<TVolume>());
+            lazyEntries = new LazyReadOnlyCollection<TEntry>(AsyncEnumerable.Empty<TEntry>());
         }
-#nullable enable
 
         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)
@@ -81,63 +65,48 @@ namespace SharpCompress.Archives
         /// <summary>
         /// Returns an ReadOnlyCollection of all the RarArchiveEntries across the one or many parts of the RarArchive.
         /// </summary>
-        public virtual ICollection<TEntry> Entries { get { return lazyEntries; } }
+        public virtual IAsyncEnumerable<TEntry> Entries => lazyEntries;
 
         /// <summary>
         /// Returns an ReadOnlyCollection of all the RarArchiveVolumes across the one or many parts of the RarArchive.
         /// </summary>
-        public ICollection<TVolume> Volumes { get { return lazyVolumes; } }
+        public IAsyncEnumerable<TVolume> Volumes => lazyVolumes;
 
         /// <summary>
         /// The total size of the files compressed in the archive.
         /// </summary>
-        public virtual long TotalSize { get { return Entries.Aggregate(0L, (total, cf) => total + cf.CompressedSize); } }
+        public virtual async ValueTask<long> TotalSizeAsync()
+        {
+            await EnsureEntriesLoaded();
+            return await Entries.AggregateAsync(0L, (total, cf) => total + cf.CompressedSize);
+        }
 
         /// <summary>
         /// The total size of the files as uncompressed in the archive.
         /// </summary>
-        public virtual long TotalUncompressSize { get { return Entries.Aggregate(0L, (total, cf) => total + cf.Size); } }
+        public virtual async ValueTask<long> TotalUncompressedSizeAsync()
+        {
+            await EnsureEntriesLoaded();
+            return await Entries.AggregateAsync(0L, (total, cf) => total + cf.Size);
+        }
 
-        protected abstract IEnumerable<TVolume> LoadVolumes(IEnumerable<Stream> streams);
-        protected abstract IEnumerable<TEntry> LoadEntries(IEnumerable<TVolume> volumes);
+        protected abstract IAsyncEnumerable<TVolume> LoadVolumes(IAsyncEnumerable<Stream> streams, CancellationToken cancellationToken);
+        protected abstract IAsyncEnumerable<TEntry> LoadEntries(IAsyncEnumerable<TVolume> volumes, CancellationToken cancellationToken);
 
-        IEnumerable<IArchiveEntry> IArchive.Entries { get { return Entries.Cast<IArchiveEntry>(); } }
+        IAsyncEnumerable<IArchiveEntry> IArchive.Entries => Entries.Select(x => (IArchiveEntry)x);
 
-        IEnumerable<IVolume> IArchive.Volumes { get { return lazyVolumes.Cast<IVolume>(); } }
+        IAsyncEnumerable<IVolume> IArchive.Volumes => lazyVolumes.Select(x => (IVolume)x);
 
-        public virtual void Dispose()
+        public virtual async ValueTask DisposeAsync()
         {
             if (!disposed)
             {
-                lazyVolumes.ForEach(v => v.Dispose());
-                lazyEntries.GetLoaded().Cast<Entry>().ForEach(x => x.Close());
+                await lazyVolumes.ForEachAsync(async v => await v.DisposeAsync());
+                await lazyEntries.GetLoaded().Cast<Entry>().ForEachAsync(async x => await x.CloseAsync());
                 disposed = true;
             }
         }
 
-        void IArchiveExtractionListener.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
@@ -149,29 +118,32 @@ namespace SharpCompress.Archives
         /// occur if this is used at the same time as other extraction methods on this instance.
         /// </summary>
         /// <returns></returns>
-        public IReader ExtractAllEntries()
+        public async ValueTask<IReader> ExtractAllEntries()
         {
-            ((IArchiveExtractionListener)this).EnsureEntriesLoaded();
-            return CreateReaderForSolidExtraction();
+            await EnsureEntriesLoaded();
+            return await CreateReaderForSolidExtraction();
+        }
+        
+        public async ValueTask EnsureEntriesLoaded()
+        {
+            await lazyEntries.EnsureFullyLoaded();
+            await lazyVolumes.EnsureFullyLoaded();
         }
 
-        protected abstract IReader CreateReaderForSolidExtraction();
+        protected abstract ValueTask<IReader> CreateReaderForSolidExtraction();
 
         /// <summary>
         /// Archive is SOLID (this means the Archive saved bytes by reusing information which helps for archives containing many small files).
         /// </summary>
-        public virtual bool IsSolid { get { return false; } }
+        public virtual ValueTask<bool> IsSolidAsync() => new(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>
-        public bool IsComplete
+        public async ValueTask<bool> IsCompleteAsync()
         {
-            get
-            {
-                ((IArchiveExtractionListener)this).EnsureEntriesLoaded();
-                return Entries.All(x => x.IsComplete);
-            }
+            await EnsureEntriesLoaded();
+            return await Entries.AllAsync(x => x.IsComplete);
         }
     }
 }

src/SharpCompress/Archives/AbstractWritableArchive.cs

@@ -2,6 +2,8 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Readers;
 using SharpCompress.Writers;
@@ -12,98 +14,126 @@ namespace SharpCompress.Archives
         where TEntry : IArchiveEntry
         where TVolume : IVolume
     {
-        private readonly List<TEntry> newEntries = new List<TEntry>();
-        private readonly List<TEntry> removedEntries = new List<TEntry>();
+        private class RebuildPauseDisposable : IAsyncDisposable
+        {
+            private readonly AbstractWritableArchive<TEntry, TVolume> archive;
 
-        private readonly List<TEntry> modifiedEntries = new List<TEntry>();
+            public RebuildPauseDisposable(AbstractWritableArchive<TEntry, TVolume> archive)
+            {
+                this.archive = archive;
+                archive.pauseRebuilding = true;
+            }
+
+            public async ValueTask DisposeAsync()
+            {
+                archive.pauseRebuilding = false;
+                await archive.RebuildModifiedCollection();
+            }
+        }
+        private readonly List<TEntry> newEntries = new();
+        private readonly List<TEntry> removedEntries = new();
+
+        private readonly List<TEntry> modifiedEntries = new();
         private bool hasModifications;
+        private bool pauseRebuilding;
 
         internal AbstractWritableArchive(ArchiveType type)
             : base(type)
         {
         }
 
-        internal AbstractWritableArchive(ArchiveType type, Stream stream, ReaderOptions readerFactoryOptions)
-            : base(type, stream.AsEnumerable(), readerFactoryOptions)
+        internal AbstractWritableArchive(ArchiveType type, Stream stream, ReaderOptions readerFactoryOptions,
+                                         CancellationToken cancellationToken)
+            : base(type, stream.AsAsyncEnumerable(), readerFactoryOptions, cancellationToken)
         {
         }
 
-        internal AbstractWritableArchive(ArchiveType type, FileInfo fileInfo, ReaderOptions readerFactoryOptions)
-            : base(type, fileInfo, readerFactoryOptions)
+        internal AbstractWritableArchive(ArchiveType type, FileInfo fileInfo, ReaderOptions readerFactoryOptions,
+                                         CancellationToken cancellationToken)
+            : base(type, fileInfo, readerFactoryOptions, cancellationToken)
         {
         }
 
-        public override ICollection<TEntry> Entries
+        public override IAsyncEnumerable<TEntry> Entries
         {
             get
             {
                 if (hasModifications)
                 {
-                    return modifiedEntries;
+                    return modifiedEntries.ToAsyncEnumerable();
                 }
                 return base.Entries;
             }
         }
 
-        private void RebuildModifiedCollection()
+        public IAsyncDisposable PauseEntryRebuilding()
         {
+            return new RebuildPauseDisposable(this);
+        }
+
+        private async ValueTask RebuildModifiedCollection()
+        {
+            if (pauseRebuilding)
+            {
+                return;
+            }
             hasModifications = true;
             newEntries.RemoveAll(v => removedEntries.Contains(v));
             modifiedEntries.Clear();
-            modifiedEntries.AddRange(OldEntries.Concat(newEntries));
+            modifiedEntries.AddRange(await OldEntries.Concat(newEntries.ToAsyncEnumerable()).ToListAsync());
         }
 
-        private IEnumerable<TEntry> OldEntries { get { return base.Entries.Where(x => !removedEntries.Contains(x)); } }
+        private IAsyncEnumerable<TEntry> OldEntries { get { return base.Entries.Where(x => !removedEntries.Contains(x)); } }
 
-        public void RemoveEntry(TEntry entry)
+        public async ValueTask RemoveEntryAsync(TEntry entry)
         {
             if (!removedEntries.Contains(entry))
             {
                 removedEntries.Add(entry);
-                RebuildModifiedCollection();
+                await RebuildModifiedCollection();
             }
         }
 
-        void IWritableArchive.RemoveEntry(IArchiveEntry entry)
+        ValueTask IWritableArchive.RemoveEntryAsync(IArchiveEntry entry, CancellationToken cancellationToken)
         {
-            RemoveEntry((TEntry)entry);
+            return RemoveEntryAsync((TEntry)entry);
         }
 
-        public TEntry AddEntry(string key, Stream source,
-                               long size = 0, DateTime? modified = null)
+        public ValueTask<TEntry>  AddEntryAsync(string key, Stream source,
+                                                       long size = 0, DateTime? modified = null, 
+                                                       CancellationToken cancellationToken = default)
         {
-            return AddEntry(key, source, false, size, modified);
+            return AddEntryAsync(key, source, false, size, modified, cancellationToken);
         }
 
-        IArchiveEntry IWritableArchive.AddEntry(string key, Stream source, bool closeStream, long size, DateTime? modified)
+        async ValueTask<IArchiveEntry> IWritableArchive.AddEntryAsync(string key, Stream source, bool closeStream, long size, DateTime? modified, CancellationToken cancellationToken)
         {
-            return AddEntry(key, source, closeStream, size, modified);
+            return await AddEntryAsync(key, source, closeStream, size, modified, cancellationToken);
         }
 
-        public TEntry AddEntry(string key, Stream source, bool closeStream,
-                               long size = 0, DateTime? modified = null)
+        public async ValueTask<TEntry> AddEntryAsync(string key, Stream source, bool closeStream,
+                                    long size = 0, DateTime? modified = null, CancellationToken cancellationToken = default)
         {
-            if (key.StartsWith("/")
-                || key.StartsWith("\\"))
+            if (key.Length > 0 && key[0] is '/' or '\\')
             {
                 key = key.Substring(1);
             }
-            if (DoesKeyMatchExisting(key))
+            if (await DoesKeyMatchExisting(key))
             {
                 throw new ArchiveException("Cannot add entry with duplicate key: " + key);
             }
-            var entry = CreateEntry(key, source, size, modified, closeStream);
+            var entry = await CreateEntry(key, source, size, modified, closeStream, cancellationToken);
             newEntries.Add(entry);
-            RebuildModifiedCollection();
+            await RebuildModifiedCollection();
             return entry;
         }
 
-        private bool DoesKeyMatchExisting(string key)
+        private async ValueTask<bool> DoesKeyMatchExisting(string key)
         {
-            foreach (var path in Entries.Select(x => x.Key))
+            await foreach (var path in Entries.Select(x => x.Key))
             {
                 var p = path.Replace('/', '\\');
-                if (p.StartsWith("\\"))
+                if (p.Length > 0 && p[0] == '\\')
                 {
                     p = p.Substring(1);
                 }
@@ -112,34 +142,35 @@ namespace SharpCompress.Archives
             return false;
         }
 
-        public void SaveTo(Stream stream, WriterOptions options)
+        public async ValueTask SaveToAsync(Stream stream, WriterOptions options, CancellationToken cancellationToken = default)
         {
             //reset streams of new entries
             newEntries.Cast<IWritableArchiveEntry>().ForEach(x => x.Stream.Seek(0, SeekOrigin.Begin));
-            SaveTo(stream, options, OldEntries, newEntries);
+            await SaveToAsync(stream, options, OldEntries, newEntries.ToAsyncEnumerable(), cancellationToken);
         }
 
-        protected TEntry CreateEntry(string key, Stream source, long size, DateTime? modified,
-                                     bool closeStream)
+        protected ValueTask<TEntry> CreateEntry(string key, Stream source, long size, DateTime? modified,
+                                                bool closeStream, CancellationToken cancellationToken)
         {
             if (!source.CanRead || !source.CanSeek)
             {
                 throw new ArgumentException("Streams must be readable and seekable to use the Writing Archive API");
             }
-            return CreateEntryInternal(key, source, size, modified, closeStream);
+            return CreateEntryInternal(key, source, size, modified, closeStream, cancellationToken);
         }
 
-        protected abstract TEntry CreateEntryInternal(string key, Stream source, long size, DateTime? modified,
-                                                      bool closeStream);
+        protected abstract ValueTask<TEntry> CreateEntryInternal(string key, Stream source, long size, DateTime? modified,
+                                                      bool closeStream, CancellationToken cancellationToken);
 
-        protected abstract void SaveTo(Stream stream, WriterOptions options, IEnumerable<TEntry> oldEntries, IEnumerable<TEntry> newEntries);
+        protected abstract ValueTask SaveToAsync(Stream stream, WriterOptions options, IAsyncEnumerable<TEntry> oldEntries, IAsyncEnumerable<TEntry> newEntries,
+                                                 CancellationToken cancellationToken = default);
 
-        public override void Dispose()
+        public override async ValueTask DisposeAsync()
         {
-            base.Dispose();
-            newEntries.Cast<Entry>().ForEach(x => x.Close());
-            removedEntries.Cast<Entry>().ForEach(x => x.Close());
-            modifiedEntries.Cast<Entry>().ForEach(x => x.Close());
+            await base.DisposeAsync();
+            await newEntries.Cast<Entry>().ForEachAsync(async x => await x.CloseAsync());
+            await removedEntries.Cast<Entry>().ForEachAsync(async x => await x.CloseAsync());
+            await modifiedEntries.Cast<Entry>().ForEachAsync(async x => await x.CloseAsync());
         }
     }
 }

src/SharpCompress/Archives/ArchiveFactory.cs

@@ -1,8 +1,10 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Archives.GZip;
-using SharpCompress.Archives.Rar;
-using SharpCompress.Archives.SevenZip;
+//using SharpCompress.Archives.Rar;
+//using SharpCompress.Archives.SevenZip;
 using SharpCompress.Archives.Tar;
 using SharpCompress.Archives.Zip;
 using SharpCompress.Common;
@@ -10,7 +12,7 @@ using SharpCompress.Readers;
 
 namespace SharpCompress.Archives
 {
-    public class ArchiveFactory
+    public static class ArchiveFactory
     {
         /// <summary>
         /// Opens an Archive for random access
@@ -18,67 +20,55 @@ namespace SharpCompress.Archives
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
         /// <returns></returns>
-        public static IArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+        public static async ValueTask<IArchive> OpenAsync(Stream stream, ReaderOptions? readerOptions = null, CancellationToken cancellationToken = default)
         {
             stream.CheckNotNull(nameof(stream));
             if (!stream.CanRead || !stream.CanSeek)
             {
                 throw new ArgumentException("Stream should be readable and seekable");
             }
-            readerOptions = readerOptions ?? new ReaderOptions();
-            if (ZipArchive.IsZipFile(stream, null))
+            readerOptions ??= new ReaderOptions();
+            if (await ZipArchive.IsZipFileAsync(stream, null, cancellationToken))
             {
                 stream.Seek(0, SeekOrigin.Begin);
                 return ZipArchive.Open(stream, readerOptions);
             }
             stream.Seek(0, SeekOrigin.Begin);
-            if (SevenZipArchive.IsSevenZipFile(stream))
+            /*if (SevenZipArchive.IsSevenZipFile(stream))
             {
                 stream.Seek(0, SeekOrigin.Begin);
                 return SevenZipArchive.Open(stream, readerOptions);
             }
-            stream.Seek(0, SeekOrigin.Begin);
-            if (GZipArchive.IsGZipFile(stream))
+            stream.Seek(0, SeekOrigin.Begin);  */
+            if (await GZipArchive.IsGZipFileAsync(stream, cancellationToken))
             {
                 stream.Seek(0, SeekOrigin.Begin);
                 return GZipArchive.Open(stream, readerOptions);
             }
             stream.Seek(0, SeekOrigin.Begin);
-            if (RarArchive.IsRarFile(stream, readerOptions))
+           /* if (RarArchive.IsRarFile(stream, readerOptions))
             {
                 stream.Seek(0, SeekOrigin.Begin);
                 return RarArchive.Open(stream, readerOptions);
             }
-            stream.Seek(0, SeekOrigin.Begin);
-            if (TarArchive.IsTarFile(stream))
+            stream.Seek(0, SeekOrigin.Begin);  */
+            if (await TarArchive.IsTarFileAsync(stream, cancellationToken))
             {
                 stream.Seek(0, SeekOrigin.Begin);
                 return TarArchive.Open(stream, readerOptions);
-            }
+            }                    
             throw new InvalidOperationException("Cannot determine compressed stream type. Supported Archive Formats: Zip, GZip, Tar, Rar, 7Zip, LZip");
         }
 
         public static IWritableArchive Create(ArchiveType type)
         {
-            switch (type)
+            return type switch
             {
-                case ArchiveType.Zip:
-                {
-                    return ZipArchive.Create();
-                }
-                case ArchiveType.Tar:
-                {
-                    return TarArchive.Create();
-                }
-                case ArchiveType.GZip:
-                {
-                    return GZipArchive.Create();
-                }
-                default:
-                {
-                    throw new NotSupportedException("Cannot create Archives of type: " + type);
-                }
-            }
+                ArchiveType.Zip => ZipArchive.Create(),
+                //ArchiveType.Tar => TarArchive.Create(),
+                ArchiveType.GZip => GZipArchive.Create(),
+                _ => throw new NotSupportedException("Cannot create Archives of type: " + type)
+            };
         }
 
         /// <summary>
@@ -86,10 +76,10 @@ namespace SharpCompress.Archives
         /// </summary>
         /// <param name="filePath"></param>
         /// <param name="options"></param>
-        public static IArchive Open(string filePath, ReaderOptions? options = null)
+        public static ValueTask<IArchive> OpenAsync(string filePath, ReaderOptions? options = null)
         {
             filePath.CheckNotNullOrEmpty(nameof(filePath));
-            return Open(new FileInfo(filePath), options);
+            return OpenAsync(new FileInfo(filePath), options);
         }
 
         /// <summary>
@@ -97,52 +87,51 @@ namespace SharpCompress.Archives
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="options"></param>
-        public static IArchive Open(FileInfo fileInfo, ReaderOptions? options = null)
+        public static async ValueTask<IArchive> OpenAsync(FileInfo fileInfo, ReaderOptions? options = null, CancellationToken cancellationToken = default)
         {
             fileInfo.CheckNotNull(nameof(fileInfo));
-            options = options ?? new ReaderOptions { LeaveStreamOpen = false };
-            using (var stream = fileInfo.OpenRead())
+            options ??= new ReaderOptions { LeaveStreamOpen = false };
+
+            await using var stream = fileInfo.OpenRead();
+            if (await ZipArchive.IsZipFileAsync(stream, null, cancellationToken))
             {
-                if (ZipArchive.IsZipFile(stream, null))
-                {
-                    return ZipArchive.Open(fileInfo, options);
-                }
-                stream.Seek(0, SeekOrigin.Begin);
-                if (SevenZipArchive.IsSevenZipFile(stream))
-                {
-                    return SevenZipArchive.Open(fileInfo, options);
-                }
-                stream.Seek(0, SeekOrigin.Begin);
-                if (GZipArchive.IsGZipFile(stream))
-                {
-                    return GZipArchive.Open(fileInfo, options);
-                }
-                stream.Seek(0, SeekOrigin.Begin);
-                if (RarArchive.IsRarFile(stream, options))
-                {
-                   return RarArchive.Open(fileInfo, options);
-                }
-                stream.Seek(0, SeekOrigin.Begin);
-                if (TarArchive.IsTarFile(stream))
-                {
-                    return TarArchive.Open(fileInfo, options);
-                }
-                throw new InvalidOperationException("Cannot determine compressed stream type. Supported Archive Formats: Zip, GZip, Tar, Rar, 7Zip");
+                return ZipArchive.Open(fileInfo, options);
             }
+            stream.Seek(0, SeekOrigin.Begin);
+            /*if (SevenZipArchive.IsSevenZipFile(stream))
+            {
+                return SevenZipArchive.Open(fileInfo, options);
+            }
+            stream.Seek(0, SeekOrigin.Begin);     */
+            if (await GZipArchive.IsGZipFileAsync(stream, cancellationToken))
+            {
+                return GZipArchive.Open(fileInfo, options);
+            }
+            stream.Seek(0, SeekOrigin.Begin);
+            /*if (RarArchive.IsRarFile(stream, options))
+            {
+                return RarArchive.Open(fileInfo, options);
+            }
+            stream.Seek(0, SeekOrigin.Begin);
+            if (TarArchive.IsTarFile(stream))
+            {
+                return TarArchive.Open(fileInfo, options);
+            }                          */
+            throw new InvalidOperationException("Cannot determine compressed stream type. Supported Archive Formats: Zip, GZip, Tar, Rar, 7Zip");
         }
 
         /// <summary>
         /// Extract to specific directory, retaining filename
         /// </summary>
-        public static void WriteToDirectory(string sourceArchive, string destinationDirectory,
-                                            ExtractionOptions? options = null)
+        public static async ValueTask WriteToDirectory(string sourceArchive, 
+                                                       string destinationDirectory,
+                                                 ExtractionOptions? options = null, 
+                                                 CancellationToken cancellationToken = default)
         {
-            using (IArchive archive = Open(sourceArchive))
+            await using IArchive archive = await OpenAsync(sourceArchive);
+            await foreach (IArchiveEntry entry in archive.Entries.WithCancellation(cancellationToken))
             {
-                foreach (IArchiveEntry entry in archive.Entries)
-                {
-                    entry.WriteToDirectory(destinationDirectory, options);
-                }
+                await entry.WriteEntryToDirectoryAsync(destinationDirectory, options, cancellationToken);
             }
         }
     }

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -1,7 +1,11 @@
 using System;
+using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.GZip;
 using SharpCompress.Readers;
@@ -29,10 +33,11 @@ namespace SharpCompress.Archives.GZip
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        public static GZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+        public static GZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null,
+                                       CancellationToken cancellationToken = default)
         {
             fileInfo.CheckNotNull(nameof(fileInfo));
-            return new GZipArchive(fileInfo, readerOptions ?? new ReaderOptions());
+            return new GZipArchive(fileInfo, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
         /// <summary>
@@ -40,10 +45,11 @@ namespace SharpCompress.Archives.GZip
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
-        public static GZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+        public static GZipArchive Open(Stream stream, ReaderOptions? readerOptions = null,
+                                       CancellationToken cancellationToken = default)
         {
             stream.CheckNotNull(nameof(stream));
-            return new GZipArchive(stream, readerOptions ?? new ReaderOptions());
+            return new GZipArchive(stream, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
         public static GZipArchive Create()
@@ -56,58 +62,58 @@ namespace SharpCompress.Archives.GZip
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="options"></param>
-        internal GZipArchive(FileInfo fileInfo, ReaderOptions options)
-            : base(ArchiveType.GZip, fileInfo, options)
+        internal GZipArchive(FileInfo fileInfo, ReaderOptions options,
+                             CancellationToken cancellationToken)
+            : base(ArchiveType.GZip, fileInfo, options, cancellationToken)
         {
         }
 
-        protected override IEnumerable<GZipVolume> LoadVolumes(FileInfo file)
+        protected override IAsyncEnumerable<GZipVolume> LoadVolumes(FileInfo file,
+                                                                    CancellationToken cancellationToken)
         {
-            return new GZipVolume(file, ReaderOptions).AsEnumerable();
+            return  new GZipVolume(file, ReaderOptions).AsAsyncEnumerable();
         }
 
-        public static bool IsGZipFile(string filePath)
+        public static ValueTask<bool> IsGZipFileAsync(string filePath, CancellationToken cancellationToken = default)
         {
-            return IsGZipFile(new FileInfo(filePath));
+            return IsGZipFileAsync(new FileInfo(filePath), cancellationToken);
         }
 
-        public static bool IsGZipFile(FileInfo fileInfo)
+        public static async ValueTask<bool> IsGZipFileAsync(FileInfo fileInfo, CancellationToken cancellationToken = default)
         {
             if (!fileInfo.Exists)
             {
                 return false;
             }
-            using (Stream stream = fileInfo.OpenRead())
-            {
-                return IsGZipFile(stream);
-            }
+
+            await using Stream stream = fileInfo.OpenRead();
+            return await IsGZipFileAsync(stream, cancellationToken);
         }
 
-        public void SaveTo(string filePath)
+        public Task SaveToAsync(string filePath, CancellationToken cancellationToken = default)
         {
-            SaveTo(new FileInfo(filePath));
+            return SaveToAsync(new FileInfo(filePath), cancellationToken);
         }
 
-        public void SaveTo(FileInfo fileInfo)
+        public async Task SaveToAsync(FileInfo fileInfo, CancellationToken cancellationToken = default)
         {
-            using (var stream = fileInfo.Open(FileMode.Create, FileAccess.Write))
-            {
-                SaveTo(stream, new WriterOptions(CompressionType.GZip));
-            }
+            await using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+            await SaveToAsync(stream, new WriterOptions(CompressionType.GZip), cancellationToken);
         }
 
-        public static bool IsGZipFile(Stream stream)
+        public static async ValueTask<bool> IsGZipFileAsync(Stream stream, CancellationToken cancellationToken = default)
         {
             // read the header on the first read
-            byte[] header = new byte[10];
+            using var header = MemoryPool<byte>.Shared.Rent(10);
+            var slice = header.Memory.Slice(0, 10);
 
             // workitem 8501: handle edge case (decompress empty stream)
-            if (!stream.ReadFully(header))
+            if (await stream.ReadAsync(slice, cancellationToken) != 10)
             {
                 return false;
             }
 
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+            if (slice.Span[0] != 0x1F || slice.Span[1] != 0x8B || slice.Span[2] != 8)
             {
                 return false;
             }
@@ -120,8 +126,9 @@ namespace SharpCompress.Archives.GZip
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="options"></param>
-        internal GZipArchive(Stream stream, ReaderOptions options)
-            : base(ArchiveType.GZip, stream, options)
+        internal GZipArchive(Stream stream, ReaderOptions options,
+                             CancellationToken cancellationToken)
+            : base(ArchiveType.GZip, stream, options, cancellationToken)
         {
         }
 
@@ -130,51 +137,54 @@ namespace SharpCompress.Archives.GZip
         {
         }
 
-        protected override GZipArchiveEntry CreateEntryInternal(string filePath, Stream source, long size, DateTime? modified,
-                                                                bool closeStream)
+        protected override async ValueTask<GZipArchiveEntry> CreateEntryInternal(string filePath, Stream source, long size, DateTime? modified,
+                                                                bool closeStream, CancellationToken cancellationToken = default)
         {
-            if (Entries.Any())
+            if (await Entries.AnyAsync(cancellationToken: cancellationToken))
             {
                 throw new InvalidOperationException("Only one entry is allowed in a GZip Archive");
             }
             return new GZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream);
         }
 
-        protected override void SaveTo(Stream stream, WriterOptions options,
-                                       IEnumerable<GZipArchiveEntry> oldEntries,
-                                       IEnumerable<GZipArchiveEntry> newEntries)
+        protected override async ValueTask SaveToAsync(Stream stream, WriterOptions options,
+                                            IAsyncEnumerable<GZipArchiveEntry> oldEntries,
+                                            IAsyncEnumerable<GZipArchiveEntry> newEntries, 
+                                            CancellationToken cancellationToken = default)
         {
-            if (Entries.Count > 1)
+            if (await Entries.CountAsync(cancellationToken: cancellationToken) > 1)
             {
                 throw new InvalidOperationException("Only one entry is allowed in a GZip Archive");
             }
-            using (var writer = new GZipWriter(stream, new GZipWriterOptions(options)))
+
+            await using var writer = new GZipWriter(stream, new GZipWriterOptions(options));
+            await foreach (var entry in oldEntries.Concat(newEntries)
+                                                  .Where(x => !x.IsDirectory)
+                                                  .WithCancellation(cancellationToken))
             {
-                foreach (var entry in oldEntries.Concat(newEntries)
-                                                .Where(x => !x.IsDirectory))
-                {
-                    using (var entryStream = entry.OpenEntryStream())
-                    {
-                        writer.Write(entry.Key, entryStream, entry.LastModifiedTime);
-                    }
-                }
+                await using var entryStream = await entry.OpenEntryStreamAsync(cancellationToken);
+                await writer.WriteAsync(entry.Key, entryStream, entry.LastModifiedTime, cancellationToken);
             }
         }
 
-        protected override IEnumerable<GZipVolume> LoadVolumes(IEnumerable<Stream> streams)
+        protected override async IAsyncEnumerable<GZipVolume> LoadVolumes(IAsyncEnumerable<Stream> streams,
+                                                                          [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            return new GZipVolume(streams.First(), ReaderOptions).AsEnumerable();
+            yield return new GZipVolume(await streams.FirstAsync(cancellationToken: cancellationToken), ReaderOptions);
         }
 
-        protected override IEnumerable<GZipArchiveEntry> LoadEntries(IEnumerable<GZipVolume> volumes)
+        protected override async IAsyncEnumerable<GZipArchiveEntry> LoadEntries(IAsyncEnumerable<GZipVolume> volumes,
+                                                                                [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            Stream stream = volumes.Single().Stream;
-            yield return new GZipArchiveEntry(this, new GZipFilePart(stream, ReaderOptions.ArchiveEncoding));
+            Stream stream = (await volumes.SingleAsync(cancellationToken: cancellationToken)).Stream;
+            var part = new GZipFilePart(ReaderOptions.ArchiveEncoding);
+            await part.Initialize(stream, cancellationToken);
+            yield return new GZipArchiveEntry(this, part);
         }
 
-        protected override IReader CreateReaderForSolidExtraction()
+        protected override async ValueTask<IReader> CreateReaderForSolidExtraction()
         {
-            var stream = Volumes.Single().Stream;
+            var stream = (await Volumes.SingleAsync()).Stream;
             stream.Position = 0;
             return GZipReader.Open(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
@@ -12,7 +14,7 @@ namespace SharpCompress.Archives.GZip
             Archive = archive;
         }
 
-        public virtual Stream OpenEntryStream()
+        public virtual async ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
             //this is to reset the stream to be read multiple times
             var part = (GZipFilePart)Parts.Single();
@@ -20,7 +22,7 @@ namespace SharpCompress.Archives.GZip
             {
                 part.GetRawStream().Position = part.EntryStartPosition;
             }
-            return Parts.Single().GetCompressedStream();
+            return await Parts.Single().GetCompressedStreamAsync(cancellationToken);
         }
 
         #region IArchiveEntry Members

src/SharpCompress/Archives/GZip/GZipWritableArchiveEntry.cs

@@ -3,6 +3,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 
@@ -50,18 +52,18 @@ namespace SharpCompress.Archives.GZip
 
         Stream IWritableArchiveEntry.Stream => stream;
 
-        public override Stream OpenEntryStream()
+        public override ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
             //ensure new stream is at the start, this could be reset
             stream.Seek(0, SeekOrigin.Begin);
-            return new NonDisposingStream(stream);
+            return new(new NonDisposingStream(stream));
         }
 
-        internal override void Close()
+        internal override async ValueTask CloseAsync()
         {
             if (closeStream)
             {
-                stream.Dispose();
+                await stream.DisposeAsync();
             }
         }
     }

src/SharpCompress/Archives/IArchive.cs

@@ -1,49 +1,44 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Readers;
 
 namespace SharpCompress.Archives
 {
-    public interface IArchive : IDisposable
+    public interface IArchive : IAsyncDisposable
     {
-        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; }
+        IAsyncEnumerable<IArchiveEntry> Entries { get; }
+        IAsyncEnumerable<IVolume> Volumes { get; }
 
         ArchiveType Type { get; }
-
+        ValueTask EnsureEntriesLoaded();
         /// <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 
         /// extracted sequentially for the best performance.
         /// </summary>
-        IReader ExtractAllEntries();
+        ValueTask<IReader> ExtractAllEntries();
 
         /// <summary>
         /// Archive is SOLID (this means the Archive saved bytes by reusing information which helps for archives containing many small files).
         /// Rar Archives can be SOLID while all 7Zip archives are considered SOLID.
         /// </summary>
-        bool IsSolid { get; }
+        ValueTask<bool> IsSolidAsync();
 
         /// <summary>
         /// This checks to see if all the known entries have IsComplete = true
         /// </summary>
-        bool IsComplete { get; }
+        ValueTask<bool> IsCompleteAsync();
 
         /// <summary>
         /// The total size of the files compressed in the archive.
         /// </summary>
-        long TotalSize { get; }
+        ValueTask<long> TotalSizeAsync();
 
         /// <summary>
         /// The total size of the files as uncompressed in the archive.
         /// </summary>
-        long TotalUncompressSize { get; }
+        ValueTask<long> TotalUncompressedSizeAsync();
     }
 }

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
@@ -9,7 +11,7 @@ namespace SharpCompress.Archives
         /// Opens the current entry as a stream that will decompress as it is read.
         /// Read the entire stream or use SkipEntry on EntryStream.
         /// </summary>
-        Stream OpenEntryStream();
+        ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// The archive can find all the parts of the archive needed to extract this entry.

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 
@@ -6,58 +8,53 @@ namespace SharpCompress.Archives
 {
     public static class IArchiveEntryExtensions
     {
-        public static void WriteTo(this IArchiveEntry archiveEntry, Stream streamToWriteTo)
+        public static async ValueTask WriteToAsync(this IArchiveEntry archiveEntry, Stream streamToWriteTo, CancellationToken cancellationToken = default)
         {
             if (archiveEntry.IsDirectory)
             {
                 throw new ExtractionException("Entry is a file directory and cannot be extracted.");
             }
 
-            var streamListener = (IArchiveExtractionListener)archiveEntry.Archive;
-            streamListener.EnsureEntriesLoaded();
-            streamListener.FireEntryExtractionBegin(archiveEntry);
-            streamListener.FireFilePartExtractionBegin(archiveEntry.Key, archiveEntry.Size, archiveEntry.CompressedSize);
-            var entryStream = archiveEntry.OpenEntryStream();
+            var archive = archiveEntry.Archive;
+            await archive.EnsureEntriesLoaded();
+            var entryStream = await archiveEntry.OpenEntryStreamAsync(cancellationToken);
             if (entryStream is null)
             {
                 return;
             }
-            using (entryStream)
+            await using (entryStream)
             {
-                using (Stream s = new ListeningStream(streamListener, entryStream))
-                {
-                    s.TransferTo(streamToWriteTo);
-                }
+                await entryStream.TransferToAsync(streamToWriteTo, cancellationToken);
             }
-            streamListener.FireEntryExtractionEnd(archiveEntry);
         }
-        
+
         /// <summary>
         /// Extract to specific directory, retaining filename
         /// </summary>
-        public static void WriteToDirectory(this IArchiveEntry entry, string destinationDirectory,
-                                            ExtractionOptions? options = null)
+        public static ValueTask WriteEntryToDirectoryAsync(this IArchiveEntry entry, 
+                                                           string destinationDirectory,
+                                                           ExtractionOptions? options = null, 
+                                                           CancellationToken cancellationToken = default)
         {
-            ExtractionMethods.WriteEntryToDirectory(entry, destinationDirectory, options,
-                                              entry.WriteToFile);
+            return ExtractionMethods.WriteEntryToDirectoryAsync(entry, destinationDirectory, options,
+                                              entry.WriteToFileAsync, cancellationToken);
         }
 
         /// <summary>
         /// Extract to specific file
         /// </summary>
-        public static void WriteToFile(this IArchiveEntry entry, 
+        public static ValueTask WriteToFileAsync(this IArchiveEntry entry,
                                        string destinationFileName,
-                                       ExtractionOptions? options = null)
+                                       ExtractionOptions? options = null, 
+                                       CancellationToken cancellationToken = default)
         {
-            
-            ExtractionMethods.WriteEntryToFile(entry, destinationFileName, options,
-                                               (x, fm) =>
+
+            return ExtractionMethods.WriteEntryToFileAsync(entry, destinationFileName, options,
+                                               async (x, fm, ct) =>
                                                {
-                                                   using (FileStream fs = File.Open(destinationFileName, fm))
-                                                   {
-                                                       entry.WriteTo(fs);
-                                                   }
-                                               });
+                                                   await using FileStream fs = File.Open(x, fm);
+                                                   await entry.WriteToAsync(fs, ct);
+                                               }, cancellationToken);
         }
     }
 }

src/SharpCompress/Archives/IArchiveExtensions.cs

@@ -1,4 +1,6 @@
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 
 namespace SharpCompress.Archives
@@ -8,12 +10,14 @@ namespace SharpCompress.Archives
         /// <summary>
         /// Extract to specific directory, retaining filename
         /// </summary>
-        public static void WriteToDirectory(this IArchive archive, string destinationDirectory,
-                                            ExtractionOptions? options = null)
+        public static async ValueTask WriteToDirectoryAsync(this IArchive archive, 
+                                            string destinationDirectory,
+                                            ExtractionOptions? options = null,
+                                            CancellationToken cancellationToken = default)
         {
-            foreach (IArchiveEntry entry in archive.Entries.Where(x => !x.IsDirectory))
+            await foreach (IArchiveEntry entry in archive.Entries.Where(x => !x.IsDirectory).WithCancellation(cancellationToken))
             {
-                entry.WriteToDirectory(destinationDirectory, options);
+                await entry.WriteEntryToDirectoryAsync(destinationDirectory, options, cancellationToken);
             }
         }
     }

src/SharpCompress/Archives/IArchiveExtractionListener.cs

@@ -1,11 +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/IWritableArchive.cs

@@ -1,15 +1,23 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Writers;
 
 namespace SharpCompress.Archives
 {
     public interface IWritableArchive : IArchive
     {
-        void RemoveEntry(IArchiveEntry entry);
+        ValueTask RemoveEntryAsync(IArchiveEntry entry, CancellationToken cancellationToken = default);
 
-        IArchiveEntry AddEntry(string key, Stream source, bool closeStream, long size = 0, DateTime? modified = null);
+        ValueTask<IArchiveEntry> AddEntryAsync(string key, Stream source, bool closeStream, long size = 0, DateTime? modified = null, CancellationToken cancellationToken = default);
 
-        void SaveTo(Stream stream, WriterOptions options);
+        ValueTask 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>
+        /// <returns>IDisposeable to resume entry rebuilding</returns>
+        IAsyncDisposable PauseEntryRebuilding();
     }
 }

src/SharpCompress/Archives/IWritableArchiveExtensions.cs

@@ -1,54 +1,62 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Writers;
 
 namespace SharpCompress.Archives
 {
     public static class IWritableArchiveExtensions
     {
-        public static void AddEntry(this IWritableArchive writableArchive,
-                                                     string entryPath, string filePath)
+        public static async ValueTask AddEntryAsync(this IWritableArchive writableArchive,
+                                         string entryPath, string filePath, 
+                                         CancellationToken cancellationToken = default)
         {
             var fileInfo = new FileInfo(filePath);
             if (!fileInfo.Exists)
             {
                 throw new FileNotFoundException("Could not AddEntry: " + filePath);
             }
-            writableArchive.AddEntry(entryPath, new FileInfo(filePath).OpenRead(), true, fileInfo.Length,
-                                     fileInfo.LastWriteTime);
+            await writableArchive.AddEntryAsync(entryPath, new FileInfo(filePath).OpenRead(), true, fileInfo.Length,
+                                     fileInfo.LastWriteTime, cancellationToken);
         }
 
-        public static void SaveTo(this IWritableArchive writableArchive, string filePath, WriterOptions options)
+        public static Task SaveToAsync(this IWritableArchive writableArchive, string filePath, WriterOptions options, CancellationToken cancellationToken = default)
         {
-            writableArchive.SaveTo(new FileInfo(filePath), options);
+            return writableArchive.SaveToAsync(new FileInfo(filePath), options, cancellationToken);
         }
 
-        public static void SaveTo(this IWritableArchive writableArchive, FileInfo fileInfo, WriterOptions options)
+        public static async Task SaveToAsync(this IWritableArchive writableArchive, FileInfo fileInfo, WriterOptions options, CancellationToken cancellationToken = default)
         {
-            using (var stream = fileInfo.Open(FileMode.Create, FileAccess.Write))
-            {
-                writableArchive.SaveTo(stream, options);
-            }
+            await using var stream = fileInfo.Open(FileMode.Create, FileAccess.Write);
+            await writableArchive.SaveToAsync(stream, options, cancellationToken);
         }
 
-        public static void AddAllFromDirectory(
+        public static async ValueTask AddAllFromDirectoryAsync(
             this IWritableArchive writableArchive,
-            string filePath, string searchPattern = "*.*", SearchOption searchOption = SearchOption.AllDirectories)
+            string filePath, string searchPattern = "*.*", 
+            SearchOption searchOption = SearchOption.AllDirectories,
+            CancellationToken cancellationToken = default)
         {
-            foreach (var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption))
+            await using (writableArchive.PauseEntryRebuilding())
             {
-                var fileInfo = new FileInfo(path);
-                writableArchive.AddEntry(path.Substring(filePath.Length), fileInfo.OpenRead(), true, fileInfo.Length,
-                                         fileInfo.LastWriteTime);
+                foreach (var path in Directory.EnumerateFiles(filePath, searchPattern, searchOption))
+                {
+                    var fileInfo = new FileInfo(path);
+                    await writableArchive.AddEntryAsync(path.Substring(filePath.Length), fileInfo.OpenRead(), true, fileInfo.Length,
+                                            fileInfo.LastWriteTime,
+                                            cancellationToken);
+                }
             }
         }
-        public static IArchiveEntry AddEntry(this IWritableArchive writableArchive, string key, FileInfo fileInfo)
+        public static ValueTask<IArchiveEntry> AddEntryAsync(this IWritableArchive writableArchive, string key, FileInfo fileInfo,
+                                                  CancellationToken cancellationToken = default)
         {
             if (!fileInfo.Exists)
             {
                 throw new ArgumentException("FileInfo does not exist.");
             }
-            return writableArchive.AddEntry(key, fileInfo.OpenRead(), true, fileInfo.Length, fileInfo.LastWriteTime);
+            return writableArchive.AddEntryAsync(key, fileInfo.OpenRead(), true, fileInfo.Length, fileInfo.LastWriteTime, cancellationToken);
         }
     }
 }

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -10,7 +10,8 @@ using SharpCompress.Readers.Rar;
 
 namespace SharpCompress.Archives.Rar
 {
-    public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
+    public class 
+        RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     {
         internal Lazy<IRarUnpack> UnpackV2017 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV2017.Unpack());
         internal Lazy<IRarUnpack> UnpackV1 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV1.Unpack());
@@ -42,7 +43,7 @@ namespace SharpCompress.Archives.Rar
 
         protected override IEnumerable<RarArchiveEntry> LoadEntries(IEnumerable<RarVolume> volumes)
         {
-            return RarArchiveEntryFactory.GetEntries(this, volumes);
+            return RarArchiveEntryFactory.GetEntries(this, volumes, ReaderOptions);
         }
 
         protected override IEnumerable<RarVolume> LoadVolumes(IEnumerable<Stream> streams)
@@ -120,7 +121,7 @@ namespace SharpCompress.Archives.Rar
                 return IsRarFile(stream);
             }
         }
-        
+
         public static bool IsRarFile(Stream stream, ReaderOptions? options = null)
         {
             try

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

@@ -6,6 +6,7 @@ using SharpCompress.Common;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
 using SharpCompress.Compressors.Rar;
+using SharpCompress.Readers;
 
 namespace SharpCompress.Archives.Rar
 {
@@ -13,11 +14,13 @@ namespace SharpCompress.Archives.Rar
     {
         private readonly ICollection<RarFilePart> parts;
         private readonly RarArchive archive;
+        private readonly ReaderOptions readerOptions;
 
-        internal RarArchiveEntry(RarArchive archive, IEnumerable<RarFilePart> parts)
+        internal RarArchiveEntry(RarArchive archive, IEnumerable<RarFilePart> parts, ReaderOptions readerOptions)
         {
             this.parts = parts.ToList();
             this.archive = archive;
+            this.readerOptions = readerOptions;
         }
 
         public override CompressionType CompressionType => CompressionType.Rar;
@@ -61,21 +64,22 @@ namespace SharpCompress.Archives.Rar
             {
                 return new RarStream(archive.UnpackV1.Value, FileHeader, new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive));
             }
-            
+
             return new RarStream(archive.UnpackV2017.Value, FileHeader, new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive));
         }
 
-        public bool IsComplete 
-        { 
-            get 
-            { 
-                return parts.Select(fp => fp.FileHeader).Any(fh => !fh.IsSplitAfter); 
-            } 
+        public bool IsComplete
+        {
+            get
+            {
+                var headers = parts.Select(x => x.FileHeader);
+                return !headers.First().IsSplitBefore && !headers.Last().IsSplitAfter;
+            }
         }
 
         private void CheckIncomplete()
         {
-            if (!IsComplete)
+            if (!readerOptions.DisableCheckIncomplete && !IsComplete)
             {
                 throw new IncompleteArchiveException("ArchiveEntry is incomplete and cannot perform this operation.");
             }

src/SharpCompress/Archives/Rar/RarArchiveEntryFactory.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using SharpCompress.Common.Rar;
+using SharpCompress.Readers;
 
 namespace SharpCompress.Archives.Rar
 {
@@ -36,11 +37,12 @@ namespace SharpCompress.Archives.Rar
         }
 
         internal static IEnumerable<RarArchiveEntry> GetEntries(RarArchive archive,
-                                                                IEnumerable<RarVolume> rarParts)
+                                                                IEnumerable<RarVolume> rarParts,
+                                                                ReaderOptions readerOptions)
         {
             foreach (var groupedParts in GetMatchedFileParts(rarParts))
             {
-                yield return new RarArchiveEntry(archive, groupedParts);
+                yield return new RarArchiveEntry(archive, groupedParts, readerOptions);
             }
         }
     }

src/SharpCompress/Archives/Rar/RarArchiveVolumeFactory.cs

@@ -23,7 +23,7 @@ namespace SharpCompress.Archives.Rar
                 yield return part;
             }
         }
-        
+
         internal static IEnumerable<RarVolume> GetParts(FileInfo fileInfo, ReaderOptions options)
         {
             FileInfoRarArchiveVolume part = new FileInfoRarArchiveVolume(fileInfo, options);
@@ -68,7 +68,7 @@ namespace SharpCompress.Archives.Rar
             // .rar, .r00, .r01, ...
             string extension = currentFileInfo.Extension;
 
-            StringBuilder buffer = new StringBuilder(currentFileInfo.FullName.Length);
+            var buffer = new StringBuilder(currentFileInfo.FullName.Length);
             buffer.Append(currentFileInfo.FullName.Substring(0,
                                                              currentFileInfo.FullName.Length - extension.Length));
             if (string.Compare(extension, ".rar", StringComparison.OrdinalIgnoreCase) == 0)
@@ -77,8 +77,7 @@ namespace SharpCompress.Archives.Rar
             }
             else
             {
-                int num = 0;
-                if (int.TryParse(extension.Substring(2, 2), out num))
+                if (int.TryParse(extension.Substring(2, 2), out int num))
                 {
                     num++;
                     buffer.Append(".r");
@@ -111,12 +110,11 @@ namespace SharpCompress.Archives.Rar
             }
             StringBuilder buffer = new StringBuilder(currentFileInfo.FullName.Length);
             buffer.Append(currentFileInfo.FullName, 0, startIndex);
-            int num = 0;
             string numString = currentFileInfo.FullName.Substring(startIndex + 5,
                                                                   currentFileInfo.FullName.IndexOf('.', startIndex + 5) -
                                                                   startIndex - 5);
             buffer.Append(".part");
-            if (int.TryParse(numString, out num))
+            if (int.TryParse(numString, out int num))
             {
                 num++;
                 for (int i = 0; i < numString.Length - num.ToString().Length; i++)

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -131,7 +131,7 @@ namespace SharpCompress.Archives.SevenZip
             }
         }
 
-        private static ReadOnlySpan<byte> SIGNATURE => new byte[] {(byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C};
+        private static ReadOnlySpan<byte> SIGNATURE => new byte[] { (byte)'7', (byte)'z', 0xBC, 0xAF, 0x27, 0x1C };
 
         private static bool SignatureMatch(Stream stream)
         {

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -2,6 +2,9 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Tar;
 using SharpCompress.Common.Tar.Headers;
@@ -31,10 +34,11 @@ namespace SharpCompress.Archives.Tar
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        public static TarArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+        public static TarArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null,
+                                      CancellationToken cancellationToken = default)
         {
             fileInfo.CheckNotNull(nameof(fileInfo));
-            return new TarArchive(fileInfo, readerOptions ?? new ReaderOptions());
+            return new TarArchive(fileInfo, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
         /// <summary>
@@ -42,35 +46,35 @@ namespace SharpCompress.Archives.Tar
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
-        public static TarArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+        public static TarArchive Open(Stream stream, ReaderOptions? readerOptions = null,
+                    CancellationToken cancellationToken = default)
         {
             stream.CheckNotNull(nameof(stream));
-            return new TarArchive(stream, readerOptions ?? new ReaderOptions());
+            return new TarArchive(stream, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
-        public static bool IsTarFile(string filePath)
+        public static ValueTask<bool> IsTarFileAsync(string filePath, CancellationToken cancellationToken = default)
         {
-            return IsTarFile(new FileInfo(filePath));
+            return IsTarFileAsync(new FileInfo(filePath), cancellationToken);
         }
 
-        public static bool IsTarFile(FileInfo fileInfo)
+        public static async ValueTask<bool> IsTarFileAsync(FileInfo fileInfo, CancellationToken cancellationToken = default)
         {
             if (!fileInfo.Exists)
             {
                 return false;
             }
-            using (Stream stream = fileInfo.OpenRead())
-            {
-                return IsTarFile(stream);
-            }
+
+            await using Stream stream = fileInfo.OpenRead();
+            return await IsTarFileAsync(stream, cancellationToken);
         }
 
-        public static bool IsTarFile(Stream stream)
+        public static async ValueTask<bool> IsTarFileAsync(Stream stream, CancellationToken cancellationToken = default)
         {
             try
             {
-                TarHeader tarHeader = new TarHeader(new ArchiveEncoding());
-                bool readSucceeded = tarHeader.Read(new BinaryReader(stream));
+                TarHeader tarHeader = new(new ArchiveEncoding());
+                bool readSucceeded = await tarHeader.Read(stream, cancellationToken);
                 bool isEmptyArchive = tarHeader.Name.Length == 0 && tarHeader.Size == 0 && Enum.IsDefined(typeof(EntryType), tarHeader.EntryType);
                 return readSucceeded || isEmptyArchive;
             }
@@ -79,20 +83,21 @@ namespace SharpCompress.Archives.Tar
             }
             return false;
         }
-        
+
         /// <summary>
         /// Constructor with a FileInfo object to an existing file.
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        internal TarArchive(FileInfo fileInfo, ReaderOptions readerOptions)
-            : base(ArchiveType.Tar, fileInfo, readerOptions)
+        internal TarArchive(FileInfo fileInfo, ReaderOptions readerOptions,
+                            CancellationToken cancellationToken)
+            : base(ArchiveType.Tar, fileInfo, readerOptions, cancellationToken)
         {
         }
 
-        protected override IEnumerable<TarVolume> LoadVolumes(FileInfo file)
+        protected override IAsyncEnumerable<TarVolume> LoadVolumes(FileInfo file, CancellationToken cancellationToken)
         {
-            return new TarVolume(file.OpenRead(), ReaderOptions).AsEnumerable();
+            return new TarVolume(file.OpenRead(), ReaderOptions).AsAsyncEnumerable();
         }
 
         /// <summary>
@@ -100,8 +105,9 @@ namespace SharpCompress.Archives.Tar
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
-        internal TarArchive(Stream stream, ReaderOptions readerOptions)
-            : base(ArchiveType.Tar, stream, readerOptions)
+        internal TarArchive(Stream stream, ReaderOptions readerOptions,
+                            CancellationToken cancellationToken)
+            : base(ArchiveType.Tar, stream, readerOptions, cancellationToken)
         {
         }
 
@@ -110,16 +116,18 @@ namespace SharpCompress.Archives.Tar
         {
         }
 
-        protected override IEnumerable<TarVolume> LoadVolumes(IEnumerable<Stream> streams)
+        protected override async IAsyncEnumerable<TarVolume> LoadVolumes(IAsyncEnumerable<Stream> streams, 
+                                                                         [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            return new TarVolume(streams.First(), ReaderOptions).AsEnumerable();
+            yield return new TarVolume(await streams.FirstAsync(cancellationToken: cancellationToken), ReaderOptions);
         }
 
-        protected override IEnumerable<TarArchiveEntry> LoadEntries(IEnumerable<TarVolume> volumes)
+        protected override async IAsyncEnumerable<TarArchiveEntry> LoadEntries(IAsyncEnumerable<TarVolume> volumes, 
+                                                                               [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            Stream stream = volumes.Single().Stream;
+            Stream stream = (await volumes.SingleAsync(cancellationToken: cancellationToken)).Stream;
             TarHeader? previousHeader = null;
-            foreach (TarHeader? header in TarHeaderFactory.ReadHeader(StreamingMode.Seekable, stream, ReaderOptions.ArchiveEncoding))
+            await foreach (TarHeader? header in TarHeaderFactory.ReadHeader(StreamingMode.Seekable, stream, ReaderOptions.ArchiveEncoding, cancellationToken))
             {
                 if (header != null)
                 {
@@ -136,11 +144,11 @@ namespace SharpCompress.Archives.Tar
 
                             var oldStreamPos = stream.Position;
 
-                            using (var entryStream = entry.OpenEntryStream())
+                            await using (var entryStream = await entry.OpenEntryStreamAsync(cancellationToken))
                             {
-                                using (var memoryStream = new MemoryStream())
+                                await using (var memoryStream = new MemoryStream())
                                 {
-                                    entryStream.TransferTo(memoryStream);
+                                    await entryStream.TransferToAsync(memoryStream, cancellationToken);
                                     memoryStream.Position = 0;
                                     var bytes = memoryStream.ToArray();
 
@@ -160,38 +168,37 @@ namespace SharpCompress.Archives.Tar
 
         public static TarArchive Create()
         {
-            return new TarArchive();
+            return new();
         }
 
-        protected override TarArchiveEntry CreateEntryInternal(string filePath, Stream source,
-                                                               long size, DateTime? modified, bool closeStream)
+        protected override ValueTask<TarArchiveEntry> CreateEntryInternal(string filePath, Stream source,
+                                                               long size, DateTime? modified, bool closeStream,
+                                                               CancellationToken cancellationToken)
         {
-            return new TarWritableArchiveEntry(this, source, CompressionType.Unknown, filePath, size, modified,
-                                               closeStream);
+            return new (new TarWritableArchiveEntry(this, source, CompressionType.Unknown, filePath, size, modified,
+                                               closeStream));
         }
 
-        protected override void SaveTo(Stream stream, WriterOptions options,
-                                       IEnumerable<TarArchiveEntry> oldEntries,
-                                       IEnumerable<TarArchiveEntry> newEntries)
+        protected override async ValueTask SaveToAsync(Stream stream, WriterOptions options,
+                                                       IAsyncEnumerable<TarArchiveEntry> oldEntries,
+                                                       IAsyncEnumerable<TarArchiveEntry> newEntries,
+                                                       CancellationToken cancellationToken = default)
         {
-            using (var writer = new TarWriter(stream, new TarWriterOptions(options)))
+            await using var writer = await TarWriter.CreateAsync(stream, new TarWriterOptions(options), cancellationToken);
+            await foreach (var entry in oldEntries.Concat(newEntries)
+                                                  .Where(x => !x.IsDirectory)
+                                                  .WithCancellation(cancellationToken))
             {
-                foreach (var entry in oldEntries.Concat(newEntries)
-                                                .Where(x => !x.IsDirectory))
-                {
-                    using (var entryStream = entry.OpenEntryStream())
-                    {
-                        writer.Write(entry.Key, entryStream, entry.LastModifiedTime, entry.Size);
-                    }
-                }
+                await using var entryStream = await entry.OpenEntryStreamAsync(cancellationToken);
+                await writer.WriteAsync(entry.Key, entryStream, entry.LastModifiedTime, entry.Size, cancellationToken);
             }
         }
 
-        protected override IReader CreateReaderForSolidExtraction()
+        protected override async ValueTask<IReader> CreateReaderForSolidExtraction()
         {
-            var stream = Volumes.Single().Stream;
+            var stream = (await Volumes.SingleAsync()).Stream;
             stream.Position = 0;
-            return TarReader.Open(stream);
+            return await TarReader.OpenAsync(stream);
         }
     }
 }

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;
 
@@ -13,9 +15,9 @@ namespace SharpCompress.Archives.Tar
             Archive = archive;
         }
 
-        public virtual Stream OpenEntryStream()
+        public virtual async ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
-            return Parts.Single().GetCompressedStream();
+            return await Parts.Single().GetCompressedStreamAsync(cancellationToken);
         }
 
         #region IArchiveEntry Members

src/SharpCompress/Archives/Tar/TarWritableArchiveEntry.cs

@@ -3,6 +3,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 
@@ -49,18 +51,18 @@ namespace SharpCompress.Archives.Tar
         internal override IEnumerable<FilePart> Parts => throw new NotImplementedException();
         Stream IWritableArchiveEntry.Stream => stream;
 
-        public override Stream OpenEntryStream()
+        public override ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
             //ensure new stream is at the start, this could be reset
             stream.Seek(0, SeekOrigin.Begin);
-            return new NonDisposingStream(stream);
+            return new(new NonDisposingStream(stream));
         }
 
-        internal override void Close()
+        internal override async ValueTask CloseAsync()
         {
             if (closeStream)
             {
-                stream.Dispose();
+                await stream.DisposeAsync();
             }
         }
     }

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -2,10 +2,14 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Common.Zip;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.Compressors.Deflate;
+using SharpCompress.IO;
 using SharpCompress.Readers;
 using SharpCompress.Readers.Zip;
 using SharpCompress.Writers;
@@ -24,7 +28,7 @@ namespace SharpCompress.Archives.Zip
         /// if the compression method is set to deflate
         /// </summary>
         public CompressionLevel DeflateCompressionLevel { get; set; }
-        
+
         /// <summary>
         /// Constructor expects a filepath to an existing file.
         /// </summary>
@@ -41,10 +45,11 @@ namespace SharpCompress.Archives.Zip
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        public static ZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
+        public static ZipArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null,
+                                      CancellationToken cancellationToken = default)
         {
             fileInfo.CheckNotNull(nameof(fileInfo));
-            return new ZipArchive(fileInfo, readerOptions ?? new ReaderOptions());
+            return new ZipArchive(fileInfo, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
         /// <summary>
@@ -52,36 +57,45 @@ namespace SharpCompress.Archives.Zip
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
-        public static ZipArchive Open(Stream stream, ReaderOptions? readerOptions = null)
+        public static ZipArchive Open(Stream stream, ReaderOptions? readerOptions = null,
+                                      CancellationToken cancellationToken = default)
         {
             stream.CheckNotNull(nameof(stream));
-            return new ZipArchive(stream, readerOptions ?? new ReaderOptions());
-        }
-        
-        public static bool IsZipFile(string filePath, string? password = null)
-        {
-            return IsZipFile(new FileInfo(filePath), password);
+            return new ZipArchive(stream, readerOptions ?? new ReaderOptions(), cancellationToken);
         }
 
-        public static bool IsZipFile(FileInfo fileInfo, string? password = null)
+        public static ValueTask<bool> IsZipFile(string filePath, string? password = null)
+        {
+            return IsZipFileAsync(new FileInfo(filePath), password);
+        }
+
+        public static async ValueTask<bool> IsZipFileAsync(FileInfo fileInfo, string? password = null)
         {
             if (!fileInfo.Exists)
             {
                 return false;
             }
-            using (Stream stream = fileInfo.OpenRead())
-            {
-                return IsZipFile(stream, password);
-            }
+
+            await using Stream stream = fileInfo.OpenRead();
+            return await IsZipFileAsync(stream, password);
         }
 
-        public static bool IsZipFile(Stream stream, string? password = null)
+        public static async ValueTask<bool> IsZipFileAsync(Stream stream, string? password = null, CancellationToken cancellationToken = default)
         {
-            StreamingZipHeaderFactory headerFactory = new StreamingZipHeaderFactory(password, new ArchiveEncoding());
+            StreamingZipHeaderFactory headerFactory = new(password, new ArchiveEncoding());
             try
             {
-                ZipHeader header =
-                    headerFactory.ReadStreamHeader(stream).FirstOrDefault(x => x.ZipHeaderType != ZipHeaderType.Split);
+                RewindableStream rewindableStream;
+                if (stream is RewindableStream rs)
+                {
+                    rewindableStream = rs;
+                }
+                else
+                {
+                    rewindableStream = new RewindableStream(stream);
+                }
+                ZipHeader? header = await headerFactory.ReadStreamHeader(rewindableStream, cancellationToken)
+                                                       .FirstOrDefaultAsync(x => x.ZipHeaderType != ZipHeaderType.Split, cancellationToken: cancellationToken);
                 if (header is null)
                 {
                     return false;
@@ -97,21 +111,23 @@ namespace SharpCompress.Archives.Zip
                 return false;
             }
         }
-        
+
         /// <summary>
         /// Constructor with a FileInfo object to an existing file.
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        internal ZipArchive(FileInfo fileInfo, ReaderOptions readerOptions)
-            : base(ArchiveType.Zip, fileInfo, readerOptions)
+        internal ZipArchive(FileInfo fileInfo, ReaderOptions readerOptions,
+                            CancellationToken cancellationToken)
+            : base(ArchiveType.Zip, fileInfo, readerOptions, cancellationToken)
         {
             headerFactory = new SeekableZipHeaderFactory(readerOptions.Password, readerOptions.ArchiveEncoding);
         }
 
-        protected override IEnumerable<ZipVolume> LoadVolumes(FileInfo file)
+        protected override IAsyncEnumerable<ZipVolume> LoadVolumes(FileInfo file,
+                                                                   CancellationToken cancellationToken)
         {
-            return new ZipVolume(file.OpenRead(), ReaderOptions).AsEnumerable();
+            return new ZipVolume(file.OpenRead(), ReaderOptions).AsAsyncEnumerable();
         }
 
         internal ZipArchive()
@@ -124,82 +140,86 @@ namespace SharpCompress.Archives.Zip
         /// </summary>
         /// <param name="stream"></param>
         /// <param name="readerOptions"></param>
-        internal ZipArchive(Stream stream, ReaderOptions readerOptions)
-            : base(ArchiveType.Zip, stream, readerOptions)
+        internal ZipArchive(Stream stream, ReaderOptions readerOptions,
+                            CancellationToken cancellationToken)
+            : base(ArchiveType.Zip, stream, readerOptions, cancellationToken)
         {
             headerFactory = new SeekableZipHeaderFactory(readerOptions.Password, readerOptions.ArchiveEncoding);
         }
 
-        protected override IEnumerable<ZipVolume> LoadVolumes(IEnumerable<Stream> streams)
+        protected override async IAsyncEnumerable<ZipVolume> LoadVolumes(IAsyncEnumerable<Stream> streams,
+                                                                         [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            return new ZipVolume(streams.First(), ReaderOptions).AsEnumerable();
+            yield return new ZipVolume(await streams.FirstAsync(cancellationToken: cancellationToken), ReaderOptions);
         }
 
-        protected override IEnumerable<ZipArchiveEntry> LoadEntries(IEnumerable<ZipVolume> volumes)
+        protected override async IAsyncEnumerable<ZipArchiveEntry> LoadEntries(IAsyncEnumerable<ZipVolume> volumes,
+                                                                               [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            var volume = volumes.Single();
+            await Task.CompletedTask;
+            var volume = await volumes.SingleAsync(cancellationToken: cancellationToken);
             Stream stream = volume.Stream;
-            foreach (ZipHeader h in headerFactory.ReadSeekableHeader(stream))
+            await foreach (ZipHeader h in headerFactory.ReadSeekableHeader(stream, cancellationToken))
             {
                 if (h != null)
                 {
                     switch (h.ZipHeaderType)
                     {
                         case ZipHeaderType.DirectoryEntry:
-                            {
-                                yield return new ZipArchiveEntry(this,
-                                                                 new SeekableZipFilePart(headerFactory,
-                                                                                         (DirectoryEntryHeader)h,
-                                                                                         stream));
-                            }
+                        {
+                            yield return new ZipArchiveEntry(this,
+                                                             new SeekableZipFilePart(headerFactory,
+                                                                                     (DirectoryEntryHeader)h,
+                                                                                     stream));
+                        }
                             break;
                         case ZipHeaderType.DirectoryEnd:
-                            {
-                                byte[] bytes = ((DirectoryEndHeader)h).Comment ?? Array.Empty<byte>();
-                                volume.Comment = ReaderOptions.ArchiveEncoding.Decode(bytes);
-                                yield break;
-                            }
+                        {
+                            byte[] bytes = ((DirectoryEndHeader)h).Comment ?? Array.Empty<byte>();
+                            volume.Comment = ReaderOptions.ArchiveEncoding.Decode(bytes);
+                            yield break;
+                        }
                     }
                 }
             }
         }
 
-        public void SaveTo(Stream stream)
+        public ValueTask SaveToAsync(Stream stream, CancellationToken cancellationToken = default)
         {
-            SaveTo(stream, new WriterOptions(CompressionType.Deflate));
+            return SaveToAsync(stream, new WriterOptions(CompressionType.Deflate), cancellationToken);
         }
 
-        protected override void SaveTo(Stream stream, WriterOptions options,
-                                       IEnumerable<ZipArchiveEntry> oldEntries,
-                                       IEnumerable<ZipArchiveEntry> newEntries)
+        protected override async ValueTask SaveToAsync(Stream stream, WriterOptions options, 
+                                                       IAsyncEnumerable<ZipArchiveEntry> oldEntries, 
+                                                       IAsyncEnumerable<ZipArchiveEntry> newEntries, 
+                                                       CancellationToken cancellationToken = default)
         {
-            using (var writer = new ZipWriter(stream, new ZipWriterOptions(options)))
+            await using var writer = new ZipWriter(stream, new ZipWriterOptions(options));
+            await foreach (var entry in oldEntries.Concat(newEntries)
+                                                  .Where(x => !x.IsDirectory)
+                                                  .WithCancellation(cancellationToken))
             {
-                foreach (var entry in oldEntries.Concat(newEntries)
-                                                .Where(x => !x.IsDirectory))
+                await using (var entryStream = await entry.OpenEntryStreamAsync(cancellationToken))
                 {
-                    using (var entryStream = entry.OpenEntryStream())
-                    {
-                        writer.Write(entry.Key, entryStream, entry.LastModifiedTime);
-                    }
+                    await writer.WriteAsync(entry.Key, entryStream, entry.LastModifiedTime, cancellationToken);
                 }
             }
         }
 
-        protected override ZipArchiveEntry CreateEntryInternal(string filePath, Stream source, long size, DateTime? modified,
-                                                               bool closeStream)
+        protected override ValueTask<ZipArchiveEntry> CreateEntryInternal(string filePath, Stream source, long size, DateTime? modified,
+                                                               bool closeStream, CancellationToken cancellationToken = default)
         {
-            return new ZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream);
+            return new(new ZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream));
         }
 
         public static ZipArchive Create()
         {
-            return new ZipArchive();
+            return new();
         }
 
-        protected override IReader CreateReaderForSolidExtraction()
+        protected override async ValueTask<IReader> CreateReaderForSolidExtraction()
         {
-            var stream = Volumes.Single().Stream;
+            var stream = (await Volumes.SingleAsync()).Stream;
             stream.Position = 0;
             return ZipReader.Open(stream, ReaderOptions);
         }

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
@@ -12,9 +14,9 @@ namespace SharpCompress.Archives.Zip
             Archive = archive;
         }
 
-        public virtual Stream OpenEntryStream()
+        public virtual ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
-            return Parts.Single().GetCompressedStream();
+            return Parts.Single().GetCompressedStreamAsync(cancellationToken);
         }
 
         #region IArchiveEntry Members

src/SharpCompress/Archives/Zip/ZipWritableArchiveEntry.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.IO;
 
@@ -49,18 +51,18 @@ namespace SharpCompress.Archives.Zip
 
         Stream IWritableArchiveEntry.Stream => stream;
 
-        public override Stream OpenEntryStream()
+        public override ValueTask<Stream> OpenEntryStreamAsync(CancellationToken cancellationToken = default)
         {
             //ensure new stream is at the start, this could be reset
             stream.Seek(0, SeekOrigin.Begin);
-            return new NonDisposingStream(stream);
+            return new(new NonDisposingStream(stream));
         }
 
-        internal override void Close()
+        internal override async ValueTask CloseAsync()
         {
             if (closeStream && !isDisposed)
             {
-                stream.Dispose();
+                await stream.DisposeAsync();
                 isDisposed = true;
             }
         }

src/SharpCompress/AsyncEnumerable.cs

@@ -0,0 +1,25 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace SharpCompress
+{
+    public static class AsyncEnumerable
+    {
+        public static IAsyncEnumerable<T> Empty<T>() => EmptyAsyncEnumerable<T>.Instance;
+        
+
+        private class EmptyAsyncEnumerable<T> : IAsyncEnumerator<T>, IAsyncEnumerable<T>
+        {
+            public static readonly EmptyAsyncEnumerable<T> Instance = 
+                new();
+            public T Current => default!;
+            public ValueTask DisposeAsync() => default;
+            public ValueTask<bool> MoveNextAsync() => new(false);
+            public IAsyncEnumerator<T> GetAsyncEnumerator(CancellationToken cancellationToken = new CancellationToken())
+            {
+                return this;
+            }
+        }
+    }
+}

src/SharpCompress/Common/ArchiveEncoding.cs

@@ -24,7 +24,7 @@ namespace SharpCompress.Common
         /// Set this when you want to use a custom method for all decoding operations.
         /// </summary>
         /// <returns>string Func(bytes, index, length)</returns>
-        public Func<byte[], int, int, string>? CustomDecoder { get; set; }
+        //public Func<byte[], int, int, string>? CustomDecoder { get; set; }
 
         public ArchiveEncoding()
         : this(Encoding.Default, Encoding.Default)
@@ -36,7 +36,7 @@ namespace SharpCompress.Common
             Password = password;
         }
 
-#if NETSTANDARD1_3 || NETSTANDARD2_0 || NETSTANDARD2_1
+#if !NET461
         static ArchiveEncoding()
         {
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
@@ -50,7 +50,12 @@ namespace SharpCompress.Common
 
         public string Decode(byte[] bytes, int start, int length)
         {
-            return GetDecoder().Invoke(bytes, start, length);
+            return GetEncoding().GetString(bytes, start, length);
+        }
+        
+        public string Decode(ReadOnlySpan<byte> span)
+        {
+            return GetEncoding().GetString(span);
         }
 
         public string DecodeUTF8(byte[] bytes)
@@ -67,10 +72,5 @@ namespace SharpCompress.Common
         {
             return Forced ?? Default ?? Encoding.UTF8;
         }
-
-        public Func<byte[], int, int, string> GetDecoder()
-        {
-            return CustomDecoder ?? ((bytes, index, count) => GetEncoding().GetString(bytes, index, count));
-        }
     }
 }

src/SharpCompress/Common/Entry.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common
 {
@@ -77,8 +78,9 @@ namespace SharpCompress.Common
 
         internal bool IsSolid { get; set; }
 
-        internal virtual void Close()
+        internal virtual ValueTask CloseAsync()
         {
+            return new ();
         }
 
         /// <summary>

src/SharpCompress/Common/EntryStream.cs

@@ -1,10 +1,13 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.IO;
 using SharpCompress.Readers;
 
 namespace SharpCompress.Common
 {
-    public class EntryStream : Stream
+    public class EntryStream : AsyncStream
     {
         private readonly IReader _reader;
         private readonly Stream _stream;
@@ -20,25 +23,24 @@ namespace SharpCompress.Common
         /// <summary>
         /// When reading a stream from OpenEntryStream, the stream must be completed so use this to finish reading the entire entry.
         /// </summary>
-        public void SkipEntry()
+        public async ValueTask SkipEntryAsync(CancellationToken cancellationToken = default)
         {
-            this.Skip();
+            await this.SkipAsync(cancellationToken);
             _completed = true;
         }
 
-        protected override void Dispose(bool disposing)
+        public override async ValueTask DisposeAsync()
         {
             if (!(_completed || _reader.Cancelled))
             {
-                SkipEntry();
+                await SkipEntryAsync();
             }
             if (_isDisposed)
             {
                 return;
             }
             _isDisposed = true;
-            base.Dispose(disposing);
-            _stream.Dispose();
+            await _stream.DisposeAsync();
         }
 
         public override bool CanRead => true;
@@ -46,17 +48,13 @@ namespace SharpCompress.Common
         public override bool CanSeek => false;
 
         public override bool CanWrite => false;
-
-        public override void Flush() {
-        }
-
         public override long Length => _stream.Length;
 
         public override long Position { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
 
-        public override int Read(byte[] buffer, int offset, int count)
+        public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
         {
-            int read = _stream.Read(buffer, offset, count);
+            int read = await _stream.ReadAsync(buffer, cancellationToken);
             if (read <= 0)
             {
                 _completed = true;
@@ -64,14 +62,14 @@ namespace SharpCompress.Common
             return read;
         }
 
-        public override int ReadByte()
+        public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
         {
-            int value = _stream.ReadByte();
-            if (value == -1)
-            {
-                _completed = true;
-            }
-            return value;
+            throw new NotSupportedException();
+        }
+
+        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            throw new NotSupportedException();
         }
 
         public override long Seek(long offset, SeekOrigin origin)
@@ -83,10 +81,5 @@ namespace SharpCompress.Common
         {
             throw new NotSupportedException();
         }
-
-        public override void Write(byte[] buffer, int offset, int count)
-        {
-            throw new NotSupportedException();
-        }
     }
 }

src/SharpCompress/Common/ExtractionMethods.cs

@@ -1,5 +1,7 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common
 {
@@ -8,30 +10,29 @@ namespace SharpCompress.Common
         /// <summary>
         /// Extract to specific directory, retaining filename
         /// </summary>
-        public static void WriteEntryToDirectory(IEntry entry, 
+        public static async ValueTask WriteEntryToDirectoryAsync(IEntry entry,
                                                  string destinationDirectory,
-                                                 ExtractionOptions? options, 
-                                                 Action<string, ExtractionOptions?> write)
+                                                 ExtractionOptions? options,
+                                                 Func<string, ExtractionOptions?, CancellationToken, ValueTask> write,
+                                                 CancellationToken cancellationToken = default)
         {
             string destinationFileName;
             string file = Path.GetFileName(entry.Key);
             string fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
 
             options ??= new ExtractionOptions()
-                        {
-                            Overwrite = true
-                        };
+            {
+                Overwrite = true
+            };
 
             if (options.ExtractFullPath)
             {
-                string folder = Path.GetDirectoryName(entry.Key);
-                string destdir = Path.GetFullPath(
-                                                  Path.Combine(fullDestinationDirectoryPath, folder)
-                                                 );
+                string folder = Path.GetDirectoryName(entry.Key)!;
+                string destdir = Path.GetFullPath(Path.Combine(fullDestinationDirectoryPath, folder));
 
                 if (!Directory.Exists(destdir))
                 {
-                    if (!destdir.StartsWith(fullDestinationDirectoryPath))
+                    if (!destdir.StartsWith(fullDestinationDirectoryPath, StringComparison.Ordinal))
                     {
                         throw new ExtractionException("Entry is trying to create a directory outside of the destination directory.");
                     }
@@ -41,7 +42,7 @@ namespace SharpCompress.Common
                 destinationFileName = Path.Combine(destdir, file);
             }
             else
-            {        
+            {
                 destinationFileName = Path.Combine(fullDestinationDirectoryPath, file);
 
             }
@@ -50,23 +51,24 @@ namespace SharpCompress.Common
             {
                 destinationFileName = Path.GetFullPath(destinationFileName);
 
-                if (!destinationFileName.StartsWith(fullDestinationDirectoryPath))
+                if (!destinationFileName.StartsWith(fullDestinationDirectoryPath, StringComparison.Ordinal))
                 {
                     throw new ExtractionException("Entry is trying to write a file outside of the destination directory.");
                 }
-                write(destinationFileName, options);
+                await write(destinationFileName, options, cancellationToken);
             }
             else if (options.ExtractFullPath && !Directory.Exists(destinationFileName))
             {
                 Directory.CreateDirectory(destinationFileName);
             }
         }
-        
-        public static void WriteEntryToFile(IEntry entry, string destinationFileName,
+
+        public static async ValueTask WriteEntryToFileAsync(IEntry entry, string destinationFileName,
                                             ExtractionOptions? options,
-                                            Action<string, FileMode> openAndWrite)
+                                            Func<string, FileMode, CancellationToken, ValueTask> openAndWrite,
+                                            CancellationToken cancellationToken = default)
         {
-            if (entry.LinkTarget != null)
+            if (entry.LinkTarget is not null)
             {
                 if (options?.WriteSymbolicLink is null)
                 {
@@ -78,16 +80,16 @@ namespace SharpCompress.Common
             {
                 FileMode fm = FileMode.Create;
                 options ??= new ExtractionOptions()
-                                {
-                                    Overwrite = true
-                                };
+                {
+                    Overwrite = true
+                };
 
                 if (!options.Overwrite)
                 {
                     fm = FileMode.CreateNew;
                 }
 
-                openAndWrite(destinationFileName, fm);
+                await openAndWrite(destinationFileName, fm, cancellationToken);
                 entry.PreserveExtractionOptions(destinationFileName, options);
             }
         }

src/SharpCompress/Common/ExtractionOptions.cs

@@ -7,7 +7,7 @@ namespace SharpCompress.Common
         /// <summary>
         /// overwrite target if it exists
         /// </summary>
-        public bool Overwrite  {get; set; }
+        public bool Overwrite { get; set; }
 
         /// <summary>
         /// extract with internal directory structure

src/SharpCompress/Common/FilePart.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common
 {
@@ -11,9 +13,9 @@ namespace SharpCompress.Common
 
         internal ArchiveEncoding ArchiveEncoding { get; }
 
-        internal abstract string FilePartName { get; }
+        internal abstract string? FilePartName { get; }
 
-        internal abstract Stream GetCompressedStream();
+        internal abstract ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken);
         internal abstract Stream? GetRawStream();
         internal bool Skipped { get; set; }
     }

src/SharpCompress/Common/GZip/GZipEntry.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
 
 namespace SharpCompress.Common.GZip
 {
@@ -15,15 +17,15 @@ namespace SharpCompress.Common.GZip
 
         public override CompressionType CompressionType => CompressionType.GZip;
 
-        public override long Crc => 0;
+        public override long Crc => _filePart.Crc ?? 0;
 
-        public override string Key => _filePart.FilePartName;
+        public override string Key => _filePart.FilePartName ?? string.Empty;
 
         public override string? LinkTarget => null;
 
         public override long CompressedSize => 0;
 
-        public override long Size => 0;
+        public override long Size => _filePart.UncompressedSize ?? 0;
 
         public override DateTime? LastModifiedTime => _filePart.DateModified;
 
@@ -41,9 +43,12 @@ namespace SharpCompress.Common.GZip
 
         internal override IEnumerable<FilePart> Parts => _filePart.AsEnumerable<FilePart>();
 
-        internal static IEnumerable<GZipEntry> GetEntries(Stream stream, OptionsBase options)
+        internal static async IAsyncEnumerable<GZipEntry> GetEntries(Stream stream, OptionsBase options,
+                                                                     [EnumeratorCancellation] CancellationToken cancellationToken)
         {
-            yield return new GZipEntry(new GZipFilePart(stream, options.ArchiveEncoding));
+            var part = new GZipFilePart(options.ArchiveEncoding);
+            await part.Initialize(stream, cancellationToken);
+            yield return new GZipEntry(part);
         }
     }
 }

src/SharpCompress/Common/GZip/GZipFilePart.cs

@@ -1,35 +1,57 @@
 using System;
+using System.Buffers;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.Compressors;
 using SharpCompress.Compressors.Deflate;
 
 namespace SharpCompress.Common.GZip
 {
-    internal class GZipFilePart : FilePart
+    internal sealed class GZipFilePart : FilePart
     {
         private string? _name;
-        private readonly Stream _stream;
+        //init only
+#nullable disable
+        private Stream _stream;
+#nullable enable
 
-        internal GZipFilePart(Stream stream, ArchiveEncoding archiveEncoding)
+        internal GZipFilePart(ArchiveEncoding archiveEncoding)
             : base(archiveEncoding)
         {
-            ReadAndValidateGzipHeader(stream);
-            EntryStartPosition = stream.Position;
-            _stream = stream;
         }
 
-        internal long EntryStartPosition { get; }
+        internal async ValueTask Initialize(Stream stream, CancellationToken cancellationToken)
+        {
+            _stream = stream;
+            if (stream.CanSeek)
+            {
+                long position = stream.Position;
+                stream.Position = stream.Length - 8;
+                await ReadTrailerAsync(cancellationToken);
+                stream.Position = position;
+            }
+            EntryStartPosition = stream.Position;
+        }
+
+        internal long EntryStartPosition { get; private set; }
 
         internal DateTime? DateModified { get; private set; }
+        internal int? Crc { get; private set; }
+        internal int? UncompressedSize { get; private set; }
 
-        internal override string FilePartName => _name!;
+        internal override string? FilePartName => _name;
 
-        internal override Stream GetCompressedStream()
+        internal override async ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
-            return new DeflateStream(_stream, CompressionMode.Decompress, CompressionLevel.Default);
+            var stream = new GZipStream(_stream, CompressionMode.Decompress, CompressionLevel.Default);
+            await stream.ReadAsync(Array.Empty<byte>(), 0, 0, cancellationToken);
+            _name = stream.FileName;
+            DateModified = stream.LastModified;
+            return stream;
         }
 
         internal override Stream GetRawStream()
@@ -37,83 +59,12 @@ namespace SharpCompress.Common.GZip
             return _stream;
         }
 
-        private void ReadAndValidateGzipHeader(Stream stream)
+        private async ValueTask ReadTrailerAsync(CancellationToken cancellationToken)
         {
-            // read the header on the first read
-            byte[] header = new byte[10];
-            int n = stream.Read(header, 0, header.Length);
+            // Read and potentially verify the GZIP trailer: CRC32 and  size mod 2^32
 
-            // workitem 8501: handle edge case (decompress empty stream)
-            if (n == 0)
-            {
-                return;
-            }
-
-            if (n != 10)
-            {
-                throw new ZlibException("Not a valid GZIP stream.");
-            }
-
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                throw new ZlibException("Bad GZIP header.");
-            }
-
-            int timet = BinaryPrimitives.ReadInt32LittleEndian(header.AsSpan(4));
-            DateModified = TarHeader.EPOCH.AddSeconds(timet);
-            if ((header[3] & 0x04) == 0x04)
-            {
-                // read and discard extra field
-                n = stream.Read(header, 0, 2); // 2-byte length field
-
-                Int16 extraLength = (Int16)(header[0] + header[1] * 256);
-                byte[] extra = new byte[extraLength];
-
-                if (!stream.ReadFully(extra))
-                {
-                    throw new ZlibException("Unexpected end-of-file reading GZIP header.");
-                }
-                n = extraLength;
-            }
-            if ((header[3] & 0x08) == 0x08)
-            {
-                _name = ReadZeroTerminatedString(stream);
-            }
-            if ((header[3] & 0x10) == 0x010)
-            {
-                ReadZeroTerminatedString(stream);
-            }
-            if ((header[3] & 0x02) == 0x02)
-            {
-                stream.ReadByte(); // CRC16, ignore
-            }
-        }
-
-        private string ReadZeroTerminatedString(Stream stream)
-        {
-            byte[] buf1 = new byte[1];
-            var list = new List<byte>();
-            bool done = false;
-            do
-            {
-                // workitem 7740
-                int n = stream.Read(buf1, 0, 1);
-                if (n != 1)
-                {
-                    throw new ZlibException("Unexpected EOF reading GZIP header.");
-                }
-                if (buf1[0] == 0)
-                {
-                    done = true;
-                }
-                else
-                {
-                    list.Add(buf1[0]);
-                }
-            }
-            while (!done);
-            byte[] buffer = list.ToArray();
-            return ArchiveEncoding.Decode(buffer);
+            Crc = await _stream.ReadInt32(cancellationToken);
+            UncompressedSize = await _stream.ReadInt32(cancellationToken);
         }
     }
 }

src/SharpCompress/Common/IVolume.cs

@@ -2,7 +2,7 @@
 
 namespace SharpCompress.Common
 {
-    public interface IVolume : IDisposable
+    public interface IVolume : IAsyncDisposable
     {
     }
 }

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

@@ -4,8 +4,8 @@ namespace SharpCompress.Common.Rar.Headers
 {
     internal class AvHeader : RarHeader
     {
-        public AvHeader(RarHeader header, RarCrcBinaryReader reader) 
-            : base(header, reader, HeaderType.Av) 
+        public AvHeader(RarHeader header, RarCrcBinaryReader reader)
+            : base(header, reader, HeaderType.Av)
         {
             if (IsRar5)
             {

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

@@ -6,7 +6,7 @@ namespace SharpCompress.Common.Rar.Headers
 {
     internal class ArchiveCryptHeader : RarHeader
     {
-        
+
         private const int CRYPT_VERSION = 0; // Supported encryption version.
         private const int SIZE_SALT50 = 16;
         private const int SIZE_SALT30 = 8;
@@ -15,14 +15,14 @@ namespace SharpCompress.Common.Rar.Headers
         private const int SIZE_PSWCHECK_CSUM = 4;
         private const int CRYPT5_KDF_LG2_COUNT = 15; // LOG2 of PDKDF2 iteration count.
         private const int CRYPT5_KDF_LG2_COUNT_MAX = 24; // LOG2 of maximum accepted iteration count.
-        
-        
+
+
         private bool _usePswCheck;
         private uint _lg2Count; // Log2 of PBKDF2 repetition count.
         private byte[] _salt;
         private byte[] _pswCheck;
         private byte[] _pswCheckCsm;
-        
+
         public ArchiveCryptHeader(RarHeader header, RarCrcBinaryReader reader)
             : base(header, reader, HeaderType.Crypt)
         {
@@ -35,12 +35,12 @@ namespace SharpCompress.Common.Rar.Headers
             {
                 //error?
                 return;
-            } 
+            }
             var encryptionFlags = reader.ReadRarVIntUInt32();
             _usePswCheck = FlagUtility.HasFlag(encryptionFlags, EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
             _lg2Count = reader.ReadRarVIntByte(1);
 
-            
+
             //UsePswCheck = HasHeaderFlag(EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
             if (_lg2Count > CRYPT5_KDF_LG2_COUNT_MAX)
             {

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

@@ -4,14 +4,14 @@ namespace SharpCompress.Common.Rar.Headers
 {
     internal sealed class ArchiveHeader : RarHeader
     {
-        public ArchiveHeader(RarHeader header, RarCrcBinaryReader reader) 
-            : base(header, reader, HeaderType.Archive) 
+        public ArchiveHeader(RarHeader header, RarCrcBinaryReader reader)
+            : base(header, reader, HeaderType.Archive)
         {
         }
 
         protected override void ReadFinish(MarkingBinaryReader reader)
         {
-            if (IsRar5) 
+            if (IsRar5)
             {
                 Flags = reader.ReadRarVIntUInt16();
                 if (HasFlag(ArchiveFlagsV5.HAS_VOLUME_NUMBER))
@@ -22,8 +22,8 @@ namespace SharpCompress.Common.Rar.Headers
                 //if (ExtraSize != 0) {
                 //    ReadLocator(reader);
                 //}
-            } 
-            else 
+            }
+            else
             {
                 Flags = HeaderFlags;
                 HighPosAv = reader.ReadInt16();
@@ -35,7 +35,8 @@ namespace SharpCompress.Common.Rar.Headers
             }
         }
 
-        private void ReadLocator(MarkingBinaryReader reader) {
+        private void ReadLocator(MarkingBinaryReader reader)
+        {
             var size = reader.ReadRarVIntUInt16();
             var type = reader.ReadRarVIntUInt16();
             if (type != 1)
@@ -47,18 +48,20 @@ namespace SharpCompress.Common.Rar.Headers
             const ushort hasQuickOpenOffset = 0x01;
             const ushort hasRecoveryOffset = 0x02;
             ulong quickOpenOffset = 0;
-            if ((flags & hasQuickOpenOffset) == hasQuickOpenOffset) { 
+            if ((flags & hasQuickOpenOffset) == hasQuickOpenOffset)
+            {
                 quickOpenOffset = reader.ReadRarVInt();
             }
             ulong recoveryOffset = 0;
-            if ((flags & hasRecoveryOffset) == hasRecoveryOffset) { 
+            if ((flags & hasRecoveryOffset) == hasRecoveryOffset)
+            {
                 recoveryOffset = reader.ReadRarVInt();
             }
         }
 
-        private ushort Flags  { get; set; }
+        private ushort Flags { get; set; }
 
-        private bool HasFlag(ushort flag) 
+        private bool HasFlag(ushort flag)
         {
             return (Flags & flag) == flag;
         }

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

@@ -5,8 +5,8 @@ namespace SharpCompress.Common.Rar.Headers
     internal class CommentHeader : RarHeader
     {
         protected CommentHeader(RarHeader header, RarCrcBinaryReader reader)
-            : base(header, reader, HeaderType.Comment) 
-        { 
+            : base(header, reader, HeaderType.Comment)
+        {
             if (IsRar5)
             {
                 throw new InvalidFormatException("unexpected rar5 record");

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

@@ -4,14 +4,14 @@ namespace SharpCompress.Common.Rar.Headers
 {
     internal class EndArchiveHeader : RarHeader
     {
-        public EndArchiveHeader(RarHeader header, RarCrcBinaryReader reader) 
-            : base(header, reader, HeaderType.EndArchive) 
+        public EndArchiveHeader(RarHeader header, RarCrcBinaryReader reader)
+            : base(header, reader, HeaderType.EndArchive)
         {
         }
 
         protected override void ReadFinish(MarkingBinaryReader reader)
         {
-            if (IsRar5) 
+            if (IsRar5)
             {
                 Flags = reader.ReadRarVIntUInt16();
             }
@@ -31,7 +31,7 @@ namespace SharpCompress.Common.Rar.Headers
 
         private ushort Flags { get; set; }
 
-        private bool HasFlag(ushort flag) 
+        private bool HasFlag(ushort flag)
         {
             return (Flags & flag) == flag;
         }

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

@@ -21,18 +21,18 @@ namespace SharpCompress.Common.Rar.Headers
     {
         private uint _fileCrc;
 
-        public FileHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType) 
-            : base(header, reader, headerType) 
+        public FileHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
+            : base(header, reader, headerType)
         {
         }
 
-        protected override void ReadFinish(MarkingBinaryReader reader) 
+        protected override void ReadFinish(MarkingBinaryReader reader)
         {
-            if (IsRar5) 
+            if (IsRar5)
             {
                 ReadFromReaderV5(reader);
-            } 
-            else 
+            }
+            else
             {
                 ReadFromReaderV4(reader);
             }
@@ -49,11 +49,13 @@ namespace SharpCompress.Common.Rar.Headers
 
             FileAttributes = reader.ReadRarVIntUInt32();
 
-            if (HasFlag(FileFlagsV5.HAS_MOD_TIME)) {
+            if (HasFlag(FileFlagsV5.HAS_MOD_TIME))
+            {
                 FileLastModifiedTime = Utility.UnixTimeToDateTime(reader.ReadUInt32());
             }
 
-            if (HasFlag(FileFlagsV5.HAS_CRC32)) {
+            if (HasFlag(FileFlagsV5.HAS_CRC32))
+            {
                 FileCrc = reader.ReadUInt32();
             }
 
@@ -65,7 +67,7 @@ namespace SharpCompress.Common.Rar.Headers
             // but it was already used in RAR 1.5 and Unpack needs to distinguish
             // them.
             CompressionAlgorithm = (byte)((compressionInfo & 0x3f) + 50);
-            
+
             // 7th bit (0x0040) defines the solid flag. If it is set, RAR continues to use the compression dictionary left after processing preceding files. 
             // It can be set only for file headers and is never set for service headers.
             IsSolid = (compressionInfo & 0x40) == 0x40;
@@ -74,7 +76,7 @@ namespace SharpCompress.Common.Rar.Headers
             CompressionMethod = (byte)((compressionInfo >> 7) & 0x7);
 
             // Bits 11 - 14 (0x3c00) define the minimum size of dictionary size required to extract data. Value 0 means 128 KB, 1 - 256 KB, ..., 14 - 2048 MB, 15 - 4096 MB.
-            WindowSize = IsDirectory ? 0 : ((size_t)0x20000) << ((compressionInfo>>10) & 0xf);
+            WindowSize = IsDirectory ? 0 : ((size_t)0x20000) << ((compressionInfo >> 10) & 0xf);
 
             HostOs = reader.ReadRarVIntByte();
 
@@ -101,18 +103,20 @@ namespace SharpCompress.Common.Rar.Headers
             FileName = ConvertPathV5(Encoding.UTF8.GetString(b, 0, b.Length));
 
             // extra size seems to be redudant since we know the total header size
-            if (ExtraSize != RemainingHeaderBytes(reader)) 
+            if (ExtraSize != RemainingHeaderBytes(reader))
             {
                 throw new InvalidFormatException("rar5 header size / extra size inconsistency");
             }
 
             isEncryptedRar5 = false;
 
-            while (RemainingHeaderBytes(reader) > 0) {
+            while (RemainingHeaderBytes(reader) > 0)
+            {
                 var size = reader.ReadRarVIntUInt16();
                 int n = RemainingHeaderBytes(reader);
                 var type = reader.ReadRarVIntUInt16();
-                switch (type) {
+                switch (type)
+                {
                     //TODO
                     case 1: // file encryption
                         {
@@ -120,7 +124,7 @@ namespace SharpCompress.Common.Rar.Headers
 
                             //var version = reader.ReadRarVIntByte();
                             //if (version != 0) throw new InvalidFormatException("unknown encryption algorithm " + version);
-                                                    }
+                        }
                         break;
                     //                    case 2: // file hash
                     //                        {
@@ -131,38 +135,41 @@ namespace SharpCompress.Common.Rar.Headers
                         {
                             ushort flags = reader.ReadRarVIntUInt16();
                             var isWindowsTime = (flags & 1) == 0;
-                            if ((flags & 0x2) == 0x2) {
+                            if ((flags & 0x2) == 0x2)
+                            {
                                 FileLastModifiedTime = ReadExtendedTimeV5(reader, isWindowsTime);
                             }
-                            if ((flags & 0x4) == 0x4) {
+                            if ((flags & 0x4) == 0x4)
+                            {
                                 FileCreatedTime = ReadExtendedTimeV5(reader, isWindowsTime);
                             }
-                            if ((flags & 0x8) == 0x8) {
+                            if ((flags & 0x8) == 0x8)
+                            {
                                 FileLastAccessedTime = ReadExtendedTimeV5(reader, isWindowsTime);
                             }
                         }
                         break;
-//TODO
-//                    case 4: // file version
-//                        {
-//
-//                        }
-//                        break;
-//                    case 5: // file system redirection
-//                        {
-//
-//                        }
-//                        break;
-//                    case 6: // unix owner
-//                        {
-//
-//                        }
-//                        break;
-//                    case 7: // service data
-//                        {
-//
-//                        }
-//                        break;
+                    //TODO
+                    //                    case 4: // file version
+                    //                        {
+                    //
+                    //                        }
+                    //                        break;
+                    //                    case 5: // file system redirection
+                    //                        {
+                    //
+                    //                        }
+                    //                        break;
+                    //                    case 6: // unix owner
+                    //                        {
+                    //
+                    //                        }
+                    //                        break;
+                    //                    case 7: // service data
+                    //                        {
+                    //
+                    //                        }
+                    //                        break;
 
                     default:
                         // skip unknown record types to allow new record types to be added in the future
@@ -171,25 +178,26 @@ namespace SharpCompress.Common.Rar.Headers
                 // drain any trailing bytes of extra record
                 int did = n - RemainingHeaderBytes(reader);
                 int drain = size - did;
-                if (drain > 0) 
+                if (drain > 0)
                 {
                     reader.ReadBytes(drain);
                 }
             }
 
-            if (AdditionalDataSize != 0) {
+            if (AdditionalDataSize != 0)
+            {
                 CompressedSize = AdditionalDataSize;
             }
         }
 
 
-        private static DateTime ReadExtendedTimeV5(MarkingBinaryReader reader, bool isWindowsTime) 
+        private static DateTime ReadExtendedTimeV5(MarkingBinaryReader reader, bool isWindowsTime)
         {
-            if (isWindowsTime) 
+            if (isWindowsTime)
             {
                 return DateTime.FromFileTime(reader.ReadInt64());
-            } 
-            else 
+            }
+            else
             {
                 return Utility.UnixTimeToDateTime(reader.ReadUInt32());
             }
@@ -201,7 +209,7 @@ namespace SharpCompress.Common.Rar.Headers
             {
                 // replace embedded \\ with valid filename char
                 return path.Replace('\\', '-').Replace('/', '\\');
-            } 
+            }
             return path;
         }
 
@@ -376,20 +384,22 @@ namespace SharpCompress.Common.Rar.Headers
 
         private ushort Flags { get; set; }
 
-        private bool HasFlag(ushort flag) 
+        private bool HasFlag(ushort flag)
         {
             return (Flags & flag) == flag;
         }
 
-        internal uint FileCrc 
-        { 
-            get { 
-                if (IsRar5 && !HasFlag(FileFlagsV5.HAS_CRC32)) {
-//!!! rar5: 
+        internal uint FileCrc
+        {
+            get
+            {
+                if (IsRar5 && !HasFlag(FileFlagsV5.HAS_CRC32))
+                {
+                    //!!! rar5: 
                     throw new InvalidOperationException("TODO rar5");
                 }
-                return _fileCrc; 
-            } 
+                return _fileCrc;
+            }
             private set => _fileCrc = value;
         }
 
@@ -409,7 +419,7 @@ namespace SharpCompress.Common.Rar.Headers
         //case 29: // rar 3.x compression
         //case 50: // RAR 5.0 compression algorithm.
         internal byte CompressionAlgorithm { get; private set; }
-        
+
         public bool IsSolid { get; private set; }
 
         // unused for UnpackV1 implementation (limitation)
@@ -427,13 +437,14 @@ namespace SharpCompress.Common.Rar.Headers
         internal long DataStartPosition { get; set; }
         public Stream PackedStream { get; set; }
 
+        public bool IsSplitBefore => IsRar5 ? HasHeaderFlag(HeaderFlagsV5.SPLIT_BEFORE) : HasFlag(FileFlagsV4.SPLIT_BEFORE);
         public bool IsSplitAfter => IsRar5 ? HasHeaderFlag(HeaderFlagsV5.SPLIT_AFTER) : HasFlag(FileFlagsV4.SPLIT_AFTER);
 
         public bool IsDirectory => HasFlag(IsRar5 ? FileFlagsV5.DIRECTORY : FileFlagsV4.DIRECTORY);
 
         private bool isEncryptedRar5 = false;
-        public bool IsEncrypted => IsRar5 ? isEncryptedRar5: HasFlag(FileFlagsV4.PASSWORD);
-        
+        public bool IsEncrypted => IsRar5 ? isEncryptedRar5 : HasFlag(FileFlagsV4.PASSWORD);
+
         internal DateTime? FileLastModifiedTime { get; private set; }
 
         internal DateTime? FileCreatedTime { get; private set; }

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

@@ -42,10 +42,10 @@ namespace SharpCompress.Common.Rar.Headers
     }
 
     internal static class EncryptionFlagsV5
-    {   
+    {
         // RAR 5.0 archive encryption header specific flags.
         public const uint CHFL_CRYPT_PSWCHECK = 0x01; // Password check data is present.
-        
+
         public const uint FHEXTRA_CRYPT_PSWCHECK = 0x01; // Password check data is present.
         public const uint FHEXTRA_CRYPT_HASHMAC = 0x02;
     }

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

@@ -1,6 +1,6 @@
 namespace SharpCompress.Common.Rar.Headers
 {
-    internal interface IRarHeader 
+    internal interface IRarHeader
     {
         HeaderType HeaderType { get; }
     }

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

@@ -11,39 +11,39 @@ namespace SharpCompress.Common.Rar.Headers
 
         public bool IsRar5 { get; }
 
-        private MarkHeader(bool isRar5) 
-        { 
+        private MarkHeader(bool isRar5)
+        {
             IsRar5 = isRar5;
         }
 
         public HeaderType HeaderType => HeaderType.Mark;
 
-        private static byte GetByte(Stream stream) 
+        private static byte GetByte(Stream stream)
         {
             var b = stream.ReadByte();
-            if (b != -1) 
+            if (b != -1)
             {
                 return (byte)b;
             }
             throw new EndOfStreamException();
         }
 
-        public static MarkHeader Read(Stream stream, bool leaveStreamOpen, bool lookForHeader) 
+        public static MarkHeader Read(Stream stream, bool leaveStreamOpen, bool lookForHeader)
         {
             int maxScanIndex = lookForHeader ? MAX_SFX_SIZE : 0;
             try
             {
                 int start = -1;
                 var b = GetByte(stream); start++;
-                while (start <= maxScanIndex) 
+                while (start <= maxScanIndex)
                 {
                     // Rar old signature: 52 45 7E 5E
                     // Rar4 signature:    52 61 72 21 1A 07 00
                     // Rar5 signature:    52 61 72 21 1A 07 01 00
-                    if (b == 0x52) 
+                    if (b == 0x52)
                     {
                         b = GetByte(stream); start++;
-                        if (b == 0x61) 
+                        if (b == 0x61)
                         {
                             b = GetByte(stream); start++;
                             if (b != 0x72)
@@ -70,7 +70,7 @@ namespace SharpCompress.Common.Rar.Headers
                             }
 
                             b = GetByte(stream); start++;
-                            if (b == 1) 
+                            if (b == 1)
                             {
                                 b = GetByte(stream); start++;
                                 if (b != 0)
@@ -79,13 +79,13 @@ namespace SharpCompress.Common.Rar.Headers
                                 }
 
                                 return new MarkHeader(true); // Rar5
-                            } 
-                            else if (b == 0) 
+                            }
+                            else if (b == 0)
                             {
                                 return new MarkHeader(false); // Rar4
-                            } 
-                        } 
-                        else if (b == 0x45) 
+                            }
+                        }
+                        else if (b == 0x45)
                         {
                             b = GetByte(stream); start++;
                             if (b != 0x7e)
@@ -100,9 +100,9 @@ namespace SharpCompress.Common.Rar.Headers
                             }
 
                             throw new InvalidFormatException("Rar format version pre-4 is unsupported.");
-                        } 
-                    } 
-                    else 
+                        }
+                    }
+                    else
                     {
                         b = GetByte(stream); start++;
                     }

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

@@ -2,23 +2,23 @@
 
 namespace SharpCompress.Common.Rar.Headers
 {
-    internal class NewSubHeaderType : IEquatable<NewSubHeaderType>
+    internal sealed class NewSubHeaderType : IEquatable<NewSubHeaderType>
     {
-        internal static readonly NewSubHeaderType SUBHEAD_TYPE_CMT = new NewSubHeaderType('C', 'M', 'T');
+        internal static readonly NewSubHeaderType SUBHEAD_TYPE_CMT = new('C', 'M', 'T');
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_ACL = new NewSubHeaderType(new byte[]{'A','C','L'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_ACL = new (new byte[]{'A','C','L'});
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_STREAM = new NewSubHeaderType(new byte[]{'S','T','M'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_STREAM = new (new byte[]{'S','T','M'});
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_UOWNER = new NewSubHeaderType(new byte[]{'U','O','W'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_UOWNER = new (new byte[]{'U','O','W'});
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_AV = new NewSubHeaderType(new byte[]{'A','V'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_AV = new (new byte[]{'A','V'});
 
-        internal static readonly NewSubHeaderType SUBHEAD_TYPE_RR = new NewSubHeaderType('R', 'R');
+        internal static readonly NewSubHeaderType SUBHEAD_TYPE_RR = new('R', 'R');
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_OS2EA = new NewSubHeaderType(new byte[]{'E','A','2'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_OS2EA = new (new byte[]{'E','A','2'});
 
-        //internal static final NewSubHeaderType SUBHEAD_TYPE_BEOSEA = new NewSubHeaderType(new byte[]{'E','A','B','E'});
+        //internal static final NewSubHeaderType SUBHEAD_TYPE_BEOSEA = new (new byte[]{'E','A','B','E'});
 
         private readonly byte[] _bytes;
 
@@ -37,19 +37,13 @@ namespace SharpCompress.Common.Rar.Headers
             {
                 return false;
             }
-            for (int i = 0; i < bytes.Length; ++i)
-            {
-                if (_bytes[i] != bytes[i])
-                {
-                    return false;
-                }
-            }
-            return true;
+
+            return _bytes.AsSpan().SequenceEqual(bytes);
         }
 
-        public bool Equals(NewSubHeaderType other)
+        public bool Equals(NewSubHeaderType? other)
         {
-            return Equals(other._bytes);
+            return other is not null && Equals(other._bytes);
         }
     }
 }

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

@@ -5,8 +5,8 @@ namespace SharpCompress.Common.Rar.Headers
     // ProtectHeader is part of the Recovery Record feature
     internal sealed class ProtectHeader : RarHeader
     {
-        public ProtectHeader(RarHeader header, RarCrcBinaryReader reader) 
-            : base(header, reader, HeaderType.Protect) 
+        public ProtectHeader(RarHeader header, RarCrcBinaryReader reader)
+            : base(header, reader, HeaderType.Protect)
         {
             if (IsRar5)
             {

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

@@ -23,12 +23,12 @@ namespace SharpCompress.Common.Rar.Headers
             }
         }
 
-        private RarHeader(RarCrcBinaryReader reader, bool isRar5, ArchiveEncoding archiveEncoding) 
+        private RarHeader(RarCrcBinaryReader reader, bool isRar5, ArchiveEncoding archiveEncoding)
         {
             _headerType = HeaderType.Null;
             _isRar5 = isRar5;
             ArchiveEncoding = archiveEncoding;
-            if (IsRar5) 
+            if (IsRar5)
             {
                 HeaderCrc = reader.ReadUInt32();
                 reader.ResetCrc();
@@ -45,7 +45,9 @@ namespace SharpCompress.Common.Rar.Headers
                 {
                     AdditionalDataSize = (long)reader.ReadRarVInt();
                 }
-            } else {
+            }
+            else
+            {
                 reader.Mark();
                 HeaderCrc = reader.ReadUInt16();
                 reader.ResetCrc();
@@ -59,7 +61,8 @@ namespace SharpCompress.Common.Rar.Headers
             }
         }
 
-        protected RarHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType) {
+        protected RarHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
+        {
             _headerType = headerType;
             _isRar5 = header.IsRar5;
             HeaderCrc = header.HeaderCrc;
@@ -80,7 +83,8 @@ namespace SharpCompress.Common.Rar.Headers
             VerifyHeaderCrc(reader.GetCrc32());
         }
 
-        protected int RemainingHeaderBytes(MarkingBinaryReader reader) {
+        protected int RemainingHeaderBytes(MarkingBinaryReader reader)
+        {
             return checked(HeaderSize - (int)reader.CurrentReadByteCount);
         }
 
@@ -108,7 +112,7 @@ namespace SharpCompress.Common.Rar.Headers
 
         protected ushort HeaderFlags { get; }
 
-        protected bool HasHeaderFlag(ushort flag) 
+        protected bool HasHeaderFlag(ushort flag)
         {
             return (HeaderFlags & flag) == flag;
         }

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

@@ -41,11 +41,11 @@ namespace SharpCompress.Common.Rar.Headers
         private RarHeader? TryReadNextHeader(Stream stream)
         {
             RarCrcBinaryReader reader;
-            if (!IsEncrypted) 
+            if (!IsEncrypted)
             {
                 reader = new RarCrcBinaryReader(stream);
-            } 
-            else 
+            }
+            else
             {
                 if (Options.Password is null)
                 {
@@ -65,7 +65,7 @@ namespace SharpCompress.Common.Rar.Headers
                 case HeaderCodeV.RAR4_ARCHIVE_HEADER:
                     {
                         var ah = new ArchiveHeader(header, reader);
-                        if (ah.IsEncrypted == true) 
+                        if (ah.IsEncrypted == true)
                         {
                             //!!! rar5 we don't know yet
                             IsEncrypted = true;
@@ -150,11 +150,11 @@ namespace SharpCompress.Common.Rar.Headers
                         return new EndArchiveHeader(header, reader);
                     }
                 case HeaderCodeV.RAR5_ARCHIVE_ENCRYPTION_HEADER:
-                {
-                    var ch = new ArchiveCryptHeader(header, reader);
-                    IsEncrypted = true;
-                    return ch;
-                }
+                    {
+                        var ch = new ArchiveCryptHeader(header, reader);
+                        IsEncrypted = true;
+                        return ch;
+                    }
                 default:
                     {
                         throw new InvalidFormatException("Unknown Rar Header: " + header.HeaderCode);
@@ -162,21 +162,26 @@ namespace SharpCompress.Common.Rar.Headers
             }
         }
 
-        private void SkipData(FileHeader fh, RarCrcBinaryReader reader) {
-            switch (StreamingMode) {
-                case StreamingMode.Seekable: {
-                    fh.DataStartPosition = reader.BaseStream.Position;
-                    reader.BaseStream.Position += fh.CompressedSize;
-                }
+        private void SkipData(FileHeader fh, RarCrcBinaryReader reader)
+        {
+            switch (StreamingMode)
+            {
+                case StreamingMode.Seekable:
+                    {
+                        fh.DataStartPosition = reader.BaseStream.Position;
+                        reader.BaseStream.Position += fh.CompressedSize;
+                    }
                     break;
-                case StreamingMode.Streaming: {
-                    //skip the data because it's useless?
-                    reader.BaseStream.Skip(fh.CompressedSize);
-                }
+                case StreamingMode.Streaming:
+                    {
+                        //skip the data because it's useless?
+                        reader.BaseStream.Skip(fh.CompressedSize);
+                    }
                     break;
-                default: {
-                    throw new InvalidFormatException("Invalid StreamingMode");
-                }
+                default:
+                    {
+                        throw new InvalidFormatException("Invalid StreamingMode");
+                    }
             }
         }
     }

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

@@ -5,8 +5,8 @@ namespace SharpCompress.Common.Rar.Headers
     internal class SignHeader : RarHeader
     {
         protected SignHeader(RarHeader header, RarCrcBinaryReader reader)
-            : base(header, reader, HeaderType.Sign) 
-        { 
+            : base(header, reader, HeaderType.Sign)
+        {
             if (IsRar5)
             {
                 throw new InvalidFormatException("unexpected rar5 record");

src/SharpCompress/Common/Rar/RarCryptoWrapper.cs

@@ -50,11 +50,11 @@ namespace SharpCompress.Common.Rar
             if (sizeToRead > 0)
             {
                 int alignedSize = sizeToRead + ((~sizeToRead + 1) & 0xf);
-                byte[] cipherText = new byte[RarRijndael.CRYPTO_BLOCK_SIZE];
+                Span<byte> cipherText = stackalloc byte[RarRijndael.CRYPTO_BLOCK_SIZE];
                 for (int i = 0; i < alignedSize / 16; i++)
                 {
                     //long ax = System.currentTimeMillis();
-                    _actualStream.Read(cipherText, 0, RarRijndael.CRYPTO_BLOCK_SIZE);
+                    _actualStream.Read(cipherText);
 
                     var readBytes = _rijndael.ProcessBlock(cipherText);
                     foreach (var readByte in readBytes)

src/SharpCompress/Common/Rar/RarEntry.cs

@@ -11,7 +11,7 @@ namespace SharpCompress.Common.Rar
         /// As the V2017 port isn't complete, add this check to use the legacy Rar code.
         /// </summary>
         internal bool IsRarV3 => FileHeader.CompressionAlgorithm == 29 || FileHeader.CompressionAlgorithm == 36;
-        
+
         /// <summary>
         /// The File's 32 bit CRC Hash
         /// </summary>

src/SharpCompress/Common/Rar/RarRijndael.cs

@@ -27,13 +27,13 @@ namespace SharpCompress.Common.Rar
 
             _rijndael = new RijndaelEngine();
             _aesInitializationVector = new byte[CRYPTO_BLOCK_SIZE];
-            int rawLength = 2*_password.Length;
+            int rawLength = 2 * _password.Length;
             byte[] rawPassword = new byte[rawLength + 8];
             byte[] passwordBytes = Encoding.UTF8.GetBytes(_password);
             for (int i = 0; i < _password.Length; i++)
             {
-                rawPassword[i*2] = passwordBytes[i];
-                rawPassword[i*2 + 1] = 0;
+                rawPassword[i * 2] = passwordBytes[i];
+                rawPassword[i * 2 + 1] = 0;
             }
             for (int i = 0; i < _salt.Length; i++)
             {
@@ -68,11 +68,11 @@ namespace SharpCompress.Common.Rar
             {
                 for (int j = 0; j < 4; j++)
                 {
-                    aesKey[i*4 + j] = (byte)
-                        (((digest[i*4]*0x1000000) & 0xff000000 |
-                          (uint) ((digest[i*4 + 1]*0x10000) & 0xff0000) |
-                          (uint) ((digest[i*4 + 2]*0x100) & 0xff00) |
-                          (uint) (digest[i*4 + 3] & 0xff)) >> (j*8));
+                    aesKey[i * 4 + j] = (byte)
+                        (((digest[i * 4] * 0x1000000) & 0xff000000 |
+                          (uint)((digest[i * 4 + 1] * 0x10000) & 0xff0000) |
+                          (uint)((digest[i * 4 + 2] * 0x100) & 0xff00) |
+                          (uint)(digest[i * 4 + 3] & 0xff)) >> (j * 8));
                 }
             }
 
@@ -87,11 +87,11 @@ namespace SharpCompress.Common.Rar
             return rijndael;
         }
 
-        public byte[] ProcessBlock(byte[] cipherText)
+        public byte[] ProcessBlock(ReadOnlySpan<byte> cipherText)
         {
-            var plainText = new byte[CRYPTO_BLOCK_SIZE];
+            Span<byte> plainText = stackalloc byte[CRYPTO_BLOCK_SIZE]; // 16 bytes
             byte[] decryptedBytes = new byte[CRYPTO_BLOCK_SIZE];
-            _rijndael.ProcessBlock(cipherText, 0, plainText, 0);
+            _rijndael.ProcessBlock(cipherText, plainText);
 
             for (int j = 0; j < CRYPTO_BLOCK_SIZE; j++)
             {

src/SharpCompress/Common/Rar/RarVolume.cs

@@ -39,20 +39,20 @@ namespace SharpCompress.Common.Rar
                 switch (header.HeaderType)
                 {
                     case HeaderType.Mark:
-                    {
-                        lastMarkHeader = (MarkHeader)header;
-                    }
+                        {
+                            lastMarkHeader = (MarkHeader)header;
+                        }
                         break;
                     case HeaderType.Archive:
-                    {
-                        ArchiveHeader = (ArchiveHeader)header;
-                    }
+                        {
+                            ArchiveHeader = (ArchiveHeader)header;
+                        }
                         break;
                     case HeaderType.File:
-                    {
-                        var fh = (FileHeader)header;
-                        yield return CreateFilePart(lastMarkHeader!, fh);
-                    }
+                        {
+                            var fh = (FileHeader)header;
+                            yield return CreateFilePart(lastMarkHeader!, fh);
+                        }
                         break;
                 }
             }

src/SharpCompress/Common/SevenZip/ArchiveDatabase.cs

@@ -89,7 +89,7 @@ namespace SharpCompress.Common.SevenZip
                 {
                     // v3.13 incorrectly worked with empty folders
                     // v4.07: Loop for skipping empty folders
-                    for (;;)
+                    for (; ; )
                     {
                         if (folderIndex >= _folders.Count)
                         {

src/SharpCompress/Common/SevenZip/ArchiveReader.cs

@@ -5,6 +5,8 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Compressors.LZMA;
 using SharpCompress.Compressors.LZMA.Utilites;
 using SharpCompress.IO;
@@ -90,7 +92,7 @@ namespace SharpCompress.Common.SevenZip
 
         private void WaitAttribute(BlockType attribute)
         {
-            for (;;)
+            for (; ; )
             {
                 BlockType? type = ReadId();
                 if (type == attribute)
@@ -452,7 +454,7 @@ namespace SharpCompress.Common.SevenZip
 #endif
 
                 BlockType? type;
-                for (;;)
+                for (; ; )
                 {
                     type = ReadId();
                     if (type == BlockType.End)
@@ -508,7 +510,7 @@ namespace SharpCompress.Common.SevenZip
                     int index = 0;
                     for (int i = 0; i < numFolders; i++)
                     {
-                        var f = new CFolder {_firstPackStreamId = index};
+                        var f = new CFolder { _firstPackStreamId = index };
                         folders.Add(f);
                         GetNextFolderItem(f);
                         index += f._packStreams.Count;
@@ -539,7 +541,7 @@ namespace SharpCompress.Common.SevenZip
 #endif
                 }
 
-                for (;;)
+                for (; ; )
                 {
                     BlockType? type = ReadId();
                     if (type == BlockType.End)
@@ -580,7 +582,7 @@ namespace SharpCompress.Common.SevenZip
                 numUnpackStreamsInFolders = null;
 
                 BlockType? type;
-                for (;;)
+                for (; ; )
                 {
                     type = ReadId();
                     if (type == BlockType.NumUnpackStream)
@@ -602,7 +604,7 @@ namespace SharpCompress.Common.SevenZip
 #endif
                         continue;
                     }
-                    if (type == BlockType.Crc || type == BlockType.Size)
+                    if (type is BlockType.Crc or BlockType.Size)
                     {
                         break;
                     }
@@ -672,7 +674,7 @@ namespace SharpCompress.Common.SevenZip
 
                 digests = null;
 
-                for (;;)
+                for (; ; )
                 {
                     if (type == BlockType.Crc)
                     {
@@ -755,7 +757,7 @@ namespace SharpCompress.Common.SevenZip
                 unpackSizes = null;
                 digests = null;
 
-                for (;;)
+                for (; ; )
                 {
                     switch (ReadId())
                     {
@@ -783,7 +785,7 @@ namespace SharpCompress.Common.SevenZip
             }
         }
 
-        private List<byte[]> ReadAndDecodePackedStreams(long baseOffset, IPasswordProvider pass)
+        private async ValueTask<List<byte[]>> ReadAndDecodePackedStreams(long baseOffset, IPasswordProvider pass, CancellationToken cancellationToken)
         {
 #if DEBUG
             Log.WriteLine("-- ReadAndDecodePackedStreams --");
@@ -791,22 +793,14 @@ namespace SharpCompress.Common.SevenZip
 #endif
             try
             {
-                long dataStartPos;
-                List<long> packSizes;
-                List<uint?> packCrCs;
-                List<CFolder> folders;
-                List<int> numUnpackStreamsInFolders;
-                List<long> unpackSizes;
-                List<uint?> digests;
-
                 ReadStreamsInfo(null,
-                                out dataStartPos,
-                                out packSizes,
-                                out packCrCs,
-                                out folders,
-                                out numUnpackStreamsInFolders,
-                                out unpackSizes,
-                                out digests);
+                                out long dataStartPos,
+                                out List<long> packSizes,
+                                out List<uint?> packCrCs,
+                                out List<CFolder> folders,
+                                out List<int> numUnpackStreamsInFolders,
+                                out List<long> unpackSizes,
+                                out List<uint?> digests);
 
                 dataStartPos += baseOffset;
 
@@ -823,8 +817,8 @@ namespace SharpCompress.Common.SevenZip
                         dataStartPos += packSize;
                     }
 
-                    var outStream = DecoderStreamHelper.CreateDecoderStream(_stream, oldDataStartPos, myPackSizes,
-                                                                            folder, pass);
+                    var outStream = await DecoderStreamHelper.CreateDecoderStream(_stream, oldDataStartPos, myPackSizes,
+                                                                            folder, pass, cancellationToken);
 
                     int unpackSize = checked((int)folder.GetUnpackSize());
                     byte[] data = new byte[unpackSize];
@@ -853,7 +847,7 @@ namespace SharpCompress.Common.SevenZip
             }
         }
 
-        private void ReadHeader(ArchiveDatabase db, IPasswordProvider getTextPassword)
+        private async ValueTask ReadHeader(ArchiveDatabase db, IPasswordProvider getTextPassword, CancellationToken cancellationToken)
         {
 #if DEBUG
             Log.WriteLine("-- ReadHeader --");
@@ -872,7 +866,7 @@ namespace SharpCompress.Common.SevenZip
                 List<byte[]> dataVector = null;
                 if (type == BlockType.AdditionalStreamsInfo)
                 {
-                    dataVector = ReadAndDecodePackedStreams(db._startPositionAfterHeader, getTextPassword);
+                    dataVector = await ReadAndDecodePackedStreams(db._startPositionAfterHeader, getTextPassword, cancellationToken);
                     type = ReadId();
                 }
 
@@ -934,7 +928,7 @@ namespace SharpCompress.Common.SevenZip
                 BitVector antiFileVector = null;
                 int numEmptyStreams = 0;
 
-                for (;;)
+                for (; ; )
                 {
                     type = ReadId();
                     if (type == BlockType.End)
@@ -969,7 +963,7 @@ namespace SharpCompress.Common.SevenZip
 #if DEBUG
                             Log.Write("WinAttributes:");
 #endif
-                            ReadAttributeVector(dataVector, numFiles, delegate(int i, uint? attr)
+                            ReadAttributeVector(dataVector, numFiles, delegate (int i, uint? attr)
                                                                       {
                                                                           // Some third party implementations established an unofficial extension
                                                                           // of the 7z archive format by placing posix file attributes in the high
@@ -1057,7 +1051,7 @@ namespace SharpCompress.Common.SevenZip
 #if DEBUG
                             Log.Write("StartPos:");
 #endif
-                            ReadNumberVector(dataVector, numFiles, delegate(int i, long? startPos)
+                            ReadNumberVector(dataVector, numFiles, delegate (int i, long? startPos)
                                                                    {
                                                                        db._files[i].StartPos = startPos;
 #if DEBUG
@@ -1072,7 +1066,7 @@ namespace SharpCompress.Common.SevenZip
 #if DEBUG
                             Log.Write("CTime:");
 #endif
-                            ReadDateTimeVector(dataVector, numFiles, delegate(int i, DateTime? time)
+                            ReadDateTimeVector(dataVector, numFiles, delegate (int i, DateTime? time)
                                                                      {
                                                                          db._files[i].CTime = time;
 #if DEBUG
@@ -1087,7 +1081,7 @@ namespace SharpCompress.Common.SevenZip
 #if DEBUG
                             Log.Write("ATime:");
 #endif
-                            ReadDateTimeVector(dataVector, numFiles, delegate(int i, DateTime? time)
+                            ReadDateTimeVector(dataVector, numFiles, delegate (int i, DateTime? time)
                                                                      {
                                                                          db._files[i].ATime = time;
 #if DEBUG
@@ -1102,7 +1096,7 @@ namespace SharpCompress.Common.SevenZip
 #if DEBUG
                             Log.Write("MTime:");
 #endif
-                            ReadDateTimeVector(dataVector, numFiles, delegate(int i, DateTime? time)
+                            ReadDateTimeVector(dataVector, numFiles, delegate (int i, DateTime? time)
                                                                      {
                                                                          db._files[i].MTime = time;
 #if DEBUG
@@ -1445,8 +1439,7 @@ namespace SharpCompress.Common.SevenZip
 
         private Stream GetCachedDecoderStream(ArchiveDatabase db, int folderIndex)
         {
-            Stream s;
-            if (!_cachedStreams.TryGetValue(folderIndex, out s))
+            if (!_cachedStreams.TryGetValue(folderIndex, out Stream s))
             {
                 CFolder folderInfo = db._folders[folderIndex];
                 int packStreamIndex = db._folders[folderIndex]._firstPackStreamId;
@@ -1494,7 +1487,7 @@ namespace SharpCompress.Common.SevenZip
             int numItems = allFilesMode
                 ? db._files.Count
                 : indices.Length;
-            
+
             if (numItems == 0)
             {
                 return;
@@ -1526,6 +1519,7 @@ namespace SharpCompress.Common.SevenZip
                 }
             }
 
+            byte[] buffer = null;
             foreach (CExtractFolderInfo efi in extractFolderInfoVector)
             {
                 int startIndex;
@@ -1562,8 +1556,8 @@ namespace SharpCompress.Common.SevenZip
 
                 Stream s = DecoderStreamHelper.CreateDecoderStream(_stream, folderStartPackPos, packSizes,
                                                                    folderInfo, db.PasswordProvider);
-                byte[] buffer = new byte[4 << 10];
-                for (;;)
+                buffer ??= new byte[4 << 10];
+                for (; ; )
                 {
                     int processed = s.Read(buffer, 0, buffer.Length);
                     if (processed == 0)

src/SharpCompress/Common/SevenZip/CMethodId.cs

@@ -1,6 +1,6 @@
 namespace SharpCompress.Common.SevenZip
 {
-    internal struct CMethodId
+    internal readonly struct CMethodId
     {
         public const ulong K_COPY_ID = 0;
         public const ulong K_LZMA_ID = 0x030101;
@@ -24,9 +24,9 @@
             return _id.GetHashCode();
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
-            return obj is CMethodId && (CMethodId)obj == this;
+            return obj is CMethodId other && Equals(other);
         }
 
         public bool Equals(CMethodId other)

src/SharpCompress/Common/SevenZip/DataReader.cs

@@ -161,7 +161,7 @@ namespace SharpCompress.Common.SevenZip
         {
             int ending = Offset;
 
-            for (;;)
+            for (; ; )
             {
                 if (ending + 2 > _ending)
                 {

src/SharpCompress/Common/SevenZip/SevenZipFilePart.cs

@@ -1,6 +1,8 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.SevenZip
@@ -35,11 +37,11 @@ namespace SharpCompress.Common.SevenZip
             return null;
         }
 
-        internal override Stream GetCompressedStream()
+        internal override async ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
             if (!Header.HasStream)
             {
-                return null!;
+                return Stream.Null;
             }
             var folderStream = _database.GetFolderStream(_stream, Folder!, _database.PasswordProvider);
 
@@ -52,7 +54,7 @@ namespace SharpCompress.Common.SevenZip
             }
             if (skipSize > 0)
             {
-                folderStream.Skip(skipSize);
+                await folderStream.SkipAsync(skipSize, cancellationToken);
             }
             return new ReadOnlySubStream(folderStream, Header.Size);
         }
@@ -84,20 +86,20 @@ namespace SharpCompress.Common.SevenZip
         {
             var coder = Folder!._coders.First();
             switch (coder._methodId._id)
-            {                
+            {
                 case K_LZMA:
                 case K_LZMA2:
-                {
-                    return CompressionType.LZMA;
-                }
+                    {
+                        return CompressionType.LZMA;
+                    }
                 case K_PPMD:
-                {
-                    return CompressionType.PPMd;
-                }
+                    {
+                        return CompressionType.PPMd;
+                    }
                 case K_B_ZIP2:
-                {
-                    return CompressionType.BZip2;
-                }
+                    {
+                        return CompressionType.BZip2;
+                    }
                 default:
                     throw new NotImplementedException();
             }

src/SharpCompress/Common/Tar/Headers/TarHeader.cs

@@ -1,13 +1,16 @@
 #nullable disable
 
 using System;
+using System.Buffers;
 using System.Buffers.Binary;
 using System.IO;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Tar.Headers
 {
-    internal class TarHeader
+    internal sealed class TarHeader
     {
         internal static readonly DateTime EPOCH = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
@@ -32,48 +35,48 @@ namespace SharpCompress.Common.Tar.Headers
 
         internal const int BLOCK_SIZE = 512;
 
-        internal void Write(Stream output)
+        internal async Task WriteAsync(Stream output)
         {
-            byte[] buffer = new byte[BLOCK_SIZE];
+            using var buffer = MemoryPool<byte>.Shared.Rent(BLOCK_SIZE);
 
-            WriteOctalBytes(511, buffer, 100, 8); // file mode
-            WriteOctalBytes(0, buffer, 108, 8); // owner ID
-            WriteOctalBytes(0, buffer, 116, 8); // group ID
+            WriteOctalBytes(511, buffer.Memory.Span, 100, 8); // file mode
+            WriteOctalBytes(0, buffer.Memory.Span, 108, 8); // owner ID
+            WriteOctalBytes(0, buffer.Memory.Span, 116, 8); // group ID
 
             //ArchiveEncoding.UTF8.GetBytes("magic").CopyTo(buffer, 257);
             var nameByteCount = ArchiveEncoding.GetEncoding().GetByteCount(Name);
             if (nameByteCount > 100)
             {
                 // Set mock filename and filetype to indicate the next block is the actual name of the file
-                WriteStringBytes("././@LongLink", buffer, 0, 100);
-                buffer[156] = (byte)EntryType.LongName;
-                WriteOctalBytes(nameByteCount + 1, buffer, 124, 12);
+                WriteStringBytes("././@LongLink", buffer.Memory.Span, 0, 100);
+                buffer.Memory.Span[156] = (byte)EntryType.LongName;
+                WriteOctalBytes(nameByteCount + 1, buffer.Memory.Span, 124, 12);
             }
             else
             {
-                WriteStringBytes(ArchiveEncoding.Encode(Name), buffer, 100);
-                WriteOctalBytes(Size, buffer, 124, 12);
+                WriteStringBytes(ArchiveEncoding.Encode(Name), buffer.Memory, 100);
+                WriteOctalBytes(Size, buffer.Memory.Span, 124, 12);
                 var time = (long)(LastModifiedTime.ToUniversalTime() - EPOCH).TotalSeconds;
-                WriteOctalBytes(time, buffer, 136, 12);
-                buffer[156] = (byte)EntryType;
+                WriteOctalBytes(time, buffer.Memory.Span, 136, 12);
+                buffer.Memory.Span[156] = (byte)EntryType;
 
                 if (Size >= 0x1FFFFFFFF)
                 {
-                    Span<byte> bytes12 = stackalloc byte[12];
-                    BinaryPrimitives.WriteInt64BigEndian(bytes12.Slice(4), Size);
-                    bytes12[0] |= 0x80;
-                    bytes12.CopyTo(buffer.AsSpan(124));
+                    using var bytes12 = MemoryPool<byte>.Shared.Rent(12);
+                    BinaryPrimitives.WriteInt64BigEndian(bytes12.Memory.Span.Slice(4), Size);
+                    bytes12.Memory.Span[0] |= 0x80;
+                    bytes12.Memory.CopyTo(buffer.Memory.Slice(124));
                 }
             }
 
-            int crc = RecalculateChecksum(buffer);
-            WriteOctalBytes(crc, buffer, 148, 8);
+            int crc = RecalculateChecksum(buffer.Memory);
+            WriteOctalBytes(crc, buffer.Memory.Span, 148, 8);
 
-            output.Write(buffer, 0, buffer.Length);
+            await output.WriteAsync(buffer.Memory.Slice(0, BLOCK_SIZE));
 
             if (nameByteCount > 100)
             {
-                WriteLongFilenameHeader(output);
+                await WriteLongFilenameHeaderAsync(output);
                 // update to short name lower than 100 - [max bytes of one character].
                 // subtracting bytes is needed because preventing infinite loop(example code is here).
                 //
@@ -82,14 +85,14 @@ namespace SharpCompress.Common.Tar.Headers
                 //
                 // and then infinite recursion is occured in WriteLongFilenameHeader because truncated.Length is 102.
                 Name = ArchiveEncoding.Decode(ArchiveEncoding.Encode(Name), 0, 100 - ArchiveEncoding.GetEncoding().GetMaxByteCount(1));
-                Write(output);
+                await WriteAsync(output);
             }
         }
 
-        private void WriteLongFilenameHeader(Stream output)
+        private async Task WriteLongFilenameHeaderAsync(Stream output)
         {
             byte[] nameBytes = ArchiveEncoding.Encode(Name);
-            output.Write(nameBytes, 0, nameBytes.Length);
+            await output.WriteAsync(nameBytes.AsMemory());
 
             // pad to multiple of BlockSize bytes, and make sure a terminating null is added
             int numPaddingBytes = BLOCK_SIZE - (nameBytes.Length % BLOCK_SIZE);
@@ -97,48 +100,56 @@ namespace SharpCompress.Common.Tar.Headers
             {
                 numPaddingBytes = BLOCK_SIZE;
             }
-            output.Write(new byte[numPaddingBytes], 0, numPaddingBytes);
+
+            using var padding = MemoryPool<byte>.Shared.Rent(numPaddingBytes);
+            padding.Memory.Span.Clear();
+            await output.WriteAsync(padding.Memory.Slice(0, numPaddingBytes));
         }
 
-        internal bool Read(BinaryReader reader)
+        internal async ValueTask<bool> Read(Stream stream, CancellationToken cancellationToken)
         {
-            var buffer = ReadBlock(reader);
-            if (buffer.Length == 0)
+            var block = MemoryPool<byte>.Shared.Rent(BLOCK_SIZE);
+            bool readFullyAsync = await stream.ReadAsync(block.Memory.Slice(0, BLOCK_SIZE), cancellationToken) == BLOCK_SIZE;
+            if (readFullyAsync is false)
             {
                 return false;
             }
 
             // for symlinks, additionally read the linkname
-            if (ReadEntryType(buffer) == EntryType.SymLink)
+            if (ReadEntryType(block.Memory.Span) == EntryType.SymLink)
             {
-                LinkName = ArchiveEncoding.Decode(buffer, 157, 100).TrimNulls();
+                LinkName = ArchiveEncoding.Decode(block.Memory.Span.Slice(157, 100)).TrimNulls();
             }
 
-            if (ReadEntryType(buffer) == EntryType.LongName)
+            if (ReadEntryType(block.Memory.Span) == EntryType.LongName)
             {
-                Name = ReadLongName(reader, buffer);
-                buffer = ReadBlock(reader);
+                Name = await ReadLongName(stream, block.Memory.Slice(0,BLOCK_SIZE), cancellationToken);
+                readFullyAsync = await stream.ReadAsync(block.Memory.Slice(0, BLOCK_SIZE), cancellationToken) == BLOCK_SIZE;
+                if (readFullyAsync is false)
+                {
+                    return false;
+                }
             }
             else
             {
-                Name = ArchiveEncoding.Decode(buffer, 0, 100).TrimNulls();
+                Name = ArchiveEncoding.Decode(block.Memory.Span.Slice( 0, 100)).TrimNulls();
             }
 
-            EntryType = ReadEntryType(buffer);
-            Size = ReadSize(buffer);
+            EntryType = ReadEntryType(block.Memory.Span);
+            Size = ReadSize(block.Memory.Slice(0, BLOCK_SIZE));
 
             //Mode = ReadASCIIInt32Base8(buffer, 100, 7);
             //UserId = ReadASCIIInt32Base8(buffer, 108, 7);
             //GroupId = ReadASCIIInt32Base8(buffer, 116, 7);
-            long unixTimeStamp = ReadAsciiInt64Base8(buffer, 136, 11);
+            long unixTimeStamp = ReadAsciiInt64Base8(block.Memory.Span.Slice(136, 11));
             LastModifiedTime = EPOCH.AddSeconds(unixTimeStamp).ToLocalTime();
 
-            Magic = ArchiveEncoding.Decode(buffer, 257, 6).TrimNulls();
+            Magic = ArchiveEncoding.Decode(block.Memory.Span.Slice( 257, 6)).TrimNulls();
 
             if (!string.IsNullOrEmpty(Magic)
                 && "ustar".Equals(Magic))
             {
-                string namePrefix = ArchiveEncoding.Decode(buffer, 345, 157);
+                string namePrefix = ArchiveEncoding.Decode(block.Memory.Span.Slice( 345, 157));
                 namePrefix = namePrefix.TrimNulls();
                 if (!string.IsNullOrEmpty(namePrefix))
                 {
@@ -153,55 +164,46 @@ namespace SharpCompress.Common.Tar.Headers
             return true;
         }
 
-        private string ReadLongName(BinaryReader reader, byte[] buffer)
+        private async ValueTask<string> ReadLongName(Stream reader, ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken)
         {
             var size = ReadSize(buffer);
             var nameLength = (int)size;
-            var nameBytes = reader.ReadBytes(nameLength);
+            using var rented = MemoryPool<byte>.Shared.Rent(nameLength);
+            var nameBytes = rented.Memory.Slice(0, nameLength);
+            await reader.ReadAsync(nameBytes, cancellationToken);
             var remainingBytesToRead = BLOCK_SIZE - (nameLength % BLOCK_SIZE);
 
             // Read the rest of the block and discard the data
             if (remainingBytesToRead < BLOCK_SIZE)
             {
-                reader.ReadBytes(remainingBytesToRead);
+                using var remaining = MemoryPool<byte>.Shared.Rent(remainingBytesToRead);
+                await reader.ReadAsync(remaining.Memory.Slice(0, remainingBytesToRead), cancellationToken);
             }
-            return ArchiveEncoding.Decode(nameBytes, 0, nameBytes.Length).TrimNulls();
+            return ArchiveEncoding.Decode(nameBytes.Span).TrimNulls();
         }
 
-        private static EntryType ReadEntryType(byte[] buffer)
+        private static EntryType ReadEntryType(Span<byte> buffer)
         {
             return (EntryType)buffer[156];
         }
 
-        private long ReadSize(byte[] buffer)
+        private long ReadSize(ReadOnlyMemory<byte> buffer)
         {
-            if ((buffer[124] & 0x80) == 0x80) // if size in binary
+            if ((buffer.Span[124] & 0x80) == 0x80) // if size in binary
             {
-                return BinaryPrimitives.ReadInt64BigEndian(buffer.AsSpan(0x80));
+                return BinaryPrimitives.ReadInt64BigEndian(buffer.Span.Slice(0x80));
             }
 
-            return ReadAsciiInt64Base8(buffer, 124, 11);
+            return ReadAsciiInt64Base8(buffer.Span.Slice(124, 11));
         }
-
-        private static byte[] ReadBlock(BinaryReader reader)
+        private static void WriteStringBytes(ReadOnlySpan<byte> name, Memory<byte> buffer, int length)
         {
-            byte[] buffer = reader.ReadBytes(BLOCK_SIZE);
-
-            if (buffer.Length != 0 && buffer.Length < BLOCK_SIZE)
-            {
-                throw new InvalidOperationException("Buffer is invalid size");
-            }
-            return buffer;
-        }
-
-        private static void WriteStringBytes(ReadOnlySpan<byte> name, Span<byte> buffer, int length)
-        {
-            name.CopyTo(buffer);
+            name.CopyTo(buffer.Span.Slice(0));
             int i = Math.Min(length, name.Length);
-            buffer.Slice(i, length - i).Clear();
+            buffer.Slice(i, length - i).Span.Clear();
         }
 
-        private static void WriteStringBytes(string name, byte[] buffer, int offset, int length)
+        private static void WriteStringBytes(string name, Span<byte> buffer, int offset, int length)
         {
             int i;
 
@@ -216,7 +218,7 @@ namespace SharpCompress.Common.Tar.Headers
             }
         }
 
-        private static void WriteOctalBytes(long value, byte[] buffer, int offset, int length)
+        private static void WriteOctalBytes(long value, Span<byte> buffer, int offset, int length)
         {
             string val = Convert.ToString(value, 8);
             int shift = length - val.Length - 1;
@@ -230,19 +232,9 @@ namespace SharpCompress.Common.Tar.Headers
             }
         }
 
-        private static int ReadAsciiInt32Base8(byte[] buffer, int offset, int count)
+        private static long ReadAsciiInt64Base8(ReadOnlySpan<byte> buffer)
         {
-            string s = Encoding.UTF8.GetString(buffer, offset, count).TrimNulls();
-            if (string.IsNullOrEmpty(s))
-            {
-                return 0;
-            }
-            return Convert.ToInt32(s, 8);
-        }
-
-        private static long ReadAsciiInt64Base8(byte[] buffer, int offset, int count)
-        {
-            string s = Encoding.UTF8.GetString(buffer, offset, count).TrimNulls();
+            string s = Encoding.UTF8.GetString(buffer).TrimNulls();
             if (string.IsNullOrEmpty(s))
             {
                 return 0;
@@ -260,38 +252,26 @@ namespace SharpCompress.Common.Tar.Headers
             return Convert.ToInt64(s);
         }
 
-        internal static int RecalculateChecksum(byte[] buf)
+
+        private static readonly byte[] eightSpaces = {
+            (byte)' ', (byte)' ', (byte)' ', (byte)' ',
+            (byte)' ', (byte)' ', (byte)' ', (byte)' '
+        };
+
+        private static int RecalculateChecksum(Memory<byte> buf)
         {
             // Set default value for checksum. That is 8 spaces.
-            Encoding.UTF8.GetBytes("        ").CopyTo(buf, 148);
+            eightSpaces.CopyTo(buf.Slice(148));
 
             // Calculate checksum
             int headerChecksum = 0;
-            foreach (byte b in buf)
+            foreach (byte b in buf.Span)
             {
                 headerChecksum += b;
             }
             return headerChecksum;
         }
 
-        internal static int RecalculateAltChecksum(byte[] buf)
-        {
-            Encoding.UTF8.GetBytes("        ").CopyTo(buf, 148);
-            int headerChecksum = 0;
-            foreach (byte b in buf)
-            {
-                if ((b & 0x80) == 0x80)
-                {
-                    headerChecksum -= b ^ 0x80;
-                }
-                else
-                {
-                    headerChecksum += b;
-                }
-            }
-            return headerChecksum;
-        }
-
         public long? DataStartPosition { get; set; }
 
         public string Magic { get; set; }

src/SharpCompress/Common/Tar/TarEntry.cs

@@ -3,6 +3,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.IO;
 
@@ -46,10 +48,11 @@ namespace SharpCompress.Common.Tar
 
         internal override IEnumerable<FilePart> Parts => _filePart.AsEnumerable<FilePart>();
 
-        internal static IEnumerable<TarEntry> GetEntries(StreamingMode mode, Stream stream,
-                                                         CompressionType compressionType, ArchiveEncoding archiveEncoding)
+        internal static async IAsyncEnumerable<TarEntry> GetEntries(StreamingMode mode, Stream stream,
+                                                         CompressionType compressionType, ArchiveEncoding archiveEncoding,
+                                                         [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            foreach (TarHeader h in TarHeaderFactory.ReadHeader(mode, stream, archiveEncoding))
+            await foreach (TarHeader h in TarHeaderFactory.ReadHeader(mode, stream, archiveEncoding, cancellationToken))
             {
                 if (h != null)
                 {

src/SharpCompress/Common/Tar/TarFilePart.cs

@@ -1,6 +1,7 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Tar.Headers;
-using SharpCompress.IO;
 
 namespace SharpCompress.Common.Tar
 {
@@ -19,14 +20,14 @@ namespace SharpCompress.Common.Tar
 
         internal override string FilePartName => Header.Name;
 
-        internal override Stream GetCompressedStream()
+        internal override ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
             if (_seekableStream != null)
             {
                 _seekableStream.Position = Header.DataStartPosition!.Value;
-                return new TarReadOnlySubStream(_seekableStream, Header.Size);
+                return new(new TarReadOnlySubStream(_seekableStream, Header.Size));
             }
-            return Header.PackedStream;
+            return new(Header.PackedStream);
         }
 
         internal override Stream? GetRawStream()

src/SharpCompress/Common/Tar/TarHeaderFactory.cs

@@ -1,5 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.IO;
 
@@ -7,17 +9,17 @@ namespace SharpCompress.Common.Tar
 {
     internal static class TarHeaderFactory
     {
-        internal static IEnumerable<TarHeader?> ReadHeader(StreamingMode mode, Stream stream, ArchiveEncoding archiveEncoding)
+        internal static async IAsyncEnumerable<TarHeader?> ReadHeader(StreamingMode mode, Stream stream, ArchiveEncoding archiveEncoding, 
+                                                                      [EnumeratorCancellation]CancellationToken cancellationToken)
         {
             while (true)
             {
                 TarHeader? header = null;
                 try
                 {
-                    BinaryReader reader = new BinaryReader(stream);
                     header = new TarHeader(archiveEncoding);
 
-                    if (!header.Read(reader))
+                    if (!await header.Read(stream, cancellationToken))
                     {
                         yield break;
                     }
@@ -25,10 +27,10 @@ namespace SharpCompress.Common.Tar
                     {
                         case StreamingMode.Seekable:
                             {
-                                header.DataStartPosition = reader.BaseStream.Position;
+                                header.DataStartPosition = stream.Position;
 
                                 //skip to nearest 512
-                                reader.BaseStream.Position += PadTo512(header.Size);
+                                stream.Position += PadTo512(header.Size);
                             }
                             break;
                         case StreamingMode.Streaming:

src/SharpCompress/Common/Tar/TarReadOnlySubStream.cs

@@ -1,6 +1,8 @@
 using SharpCompress.IO;
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Tar
 {
@@ -14,7 +16,7 @@ namespace SharpCompress.Common.Tar
             BytesLeftToRead = bytesToRead;
         }
 
-        protected override void Dispose(bool disposing)
+        public override async ValueTask DisposeAsync()
         {
             if (_isDisposed)
             {
@@ -23,22 +25,17 @@ namespace SharpCompress.Common.Tar
 
             _isDisposed = true;
 
-            if (disposing)
+            // Ensure we read all remaining blocks for this entry.
+            await Stream.SkipAsync(BytesLeftToRead);
+            _amountRead += BytesLeftToRead;
+
+            // If the last block wasn't a full 512 bytes, skip the remaining padding bytes.
+            var bytesInLastBlock = _amountRead % 512;
+
+            if (bytesInLastBlock != 0)
             {
-                // Ensure we read all remaining blocks for this entry.
-                Stream.Skip(BytesLeftToRead);
-                _amountRead += BytesLeftToRead;
-
-                // If the last block wasn't a full 512 bytes, skip the remaining padding bytes.
-                var bytesInLastBlock = _amountRead % 512;
-
-                if (bytesInLastBlock != 0)
-                {
-                    Stream.Skip(512 - bytesInLastBlock);
-                }
+                await Stream.SkipAsync(512 - bytesInLastBlock);
             }
-
-            base.Dispose(disposing);
         }
 
         private long BytesLeftToRead { get; set; }
@@ -49,22 +46,18 @@ namespace SharpCompress.Common.Tar
 
         public override bool CanWrite => false;
 
-        public override void Flush()
-        {
-            throw new NotSupportedException();
-        }
-
         public override long Length => throw new NotSupportedException();
 
         public override long Position { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
 
-        public override int Read(byte[] buffer, int offset, int count)
+        public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
         {
-            if (BytesLeftToRead < count)
+            var count = buffer.Length;
+            if (BytesLeftToRead < buffer.Length)
             {
                 count = (int)BytesLeftToRead;
             }
-            int read = Stream.Read(buffer, offset, count);
+            int read = await Stream.ReadAsync(buffer.Slice(0, count), cancellationToken);
             if (read > 0)
             {
                 BytesLeftToRead -= read;
@@ -73,20 +66,9 @@ namespace SharpCompress.Common.Tar
             return read;
         }
 
-        public override int ReadByte()
+        public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
-            if (BytesLeftToRead <= 0)
-            {
-                return -1;
-            }
-            int value = Stream.ReadByte();
-            if (value != -1)
-            {
-                --BytesLeftToRead;
-                ++_amountRead;
-            }
-            return value;
-
+            throw new NotSupportedException();
         }
 
         public override long Seek(long offset, SeekOrigin origin)
@@ -98,10 +80,5 @@ namespace SharpCompress.Common.Tar
         {
             throw new NotSupportedException();
         }
-
-        public override void Write(byte[] buffer, int offset, int count)
-        {
-            throw new NotSupportedException();
-        }
     }
 }

src/SharpCompress/Common/Volume.cs

@@ -1,5 +1,5 @@
-using System;
-using System.IO;
+using System.IO;
+using System.Threading.Tasks;
 using SharpCompress.IO;
 using SharpCompress.Readers;
 
@@ -33,19 +33,10 @@ namespace SharpCompress.Common
         /// RarArchive is part of a multi-part archive.
         /// </summary>
         public virtual bool IsMultiVolume => true;
-
-        protected virtual void Dispose(bool disposing)
+        
+        public ValueTask DisposeAsync()
         {
-            if (disposing)
-            {
-                _actualStream.Dispose();
-            }
-        }
-
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
+            return _actualStream.DisposeAsync();
         }
     }
 }

src/SharpCompress/Common/Zip/Headers/DirectoryEndHeader.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -9,29 +11,29 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override async ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
-            VolumeNumber = reader.ReadUInt16();
-            FirstVolumeWithDirectory = reader.ReadUInt16();
-            TotalNumberOfEntriesInDisk = reader.ReadUInt16();
-            TotalNumberOfEntries = reader.ReadUInt16();
-            DirectorySize = reader.ReadUInt32();
-            DirectoryStartOffsetRelativeToDisk = reader.ReadUInt32();
-            CommentLength = reader.ReadUInt16();
-            Comment = reader.ReadBytes(CommentLength);
+            VolumeNumber = await stream.ReadUInt16(cancellationToken);
+            FirstVolumeWithDirectory = await stream.ReadUInt16(cancellationToken);
+            TotalNumberOfEntriesInDisk = await stream.ReadUInt16(cancellationToken);
+            TotalNumberOfEntries = await stream.ReadUInt16(cancellationToken);
+            DirectorySize = await stream.ReadUInt32(cancellationToken);
+            DirectoryStartOffsetRelativeToDisk = await stream.ReadUInt32(cancellationToken);
+            CommentLength = await stream.ReadUInt16(cancellationToken);
+            Comment = await stream.ReadBytes(CommentLength ?? 0, cancellationToken);
         }
 
-        public ushort VolumeNumber { get; private set; }
+        public ushort? VolumeNumber { get; private set; }
 
-        public ushort FirstVolumeWithDirectory { get; private set; }
+        public ushort? FirstVolumeWithDirectory { get; private set; }
 
-        public ushort TotalNumberOfEntriesInDisk { get; private set; }
+        public ushort? TotalNumberOfEntriesInDisk { get; private set; }
 
-        public uint DirectorySize { get; private set; }
+        public uint? DirectorySize { get; private set; }
 
-        public uint DirectoryStartOffsetRelativeToDisk { get; private set; }
+        public uint? DirectoryStartOffsetRelativeToDisk { get; private set; }
 
-        public ushort CommentLength { get; private set; }
+        public ushort? CommentLength { get; private set; }
 
         public byte[]? Comment { get; private set; }
 

src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs

@@ -1,5 +1,7 @@
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -10,29 +12,29 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override async ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
-            Version = reader.ReadUInt16();
-            VersionNeededToExtract = reader.ReadUInt16();
-            Flags = (HeaderFlags)reader.ReadUInt16();
-            CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-            LastModifiedTime = reader.ReadUInt16();
-            LastModifiedDate = reader.ReadUInt16();
-            Crc = reader.ReadUInt32();
-            CompressedSize = reader.ReadUInt32();
-            UncompressedSize = reader.ReadUInt32();
-            ushort nameLength = reader.ReadUInt16();
-            ushort extraLength = reader.ReadUInt16();
-            ushort commentLength = reader.ReadUInt16();
-            DiskNumberStart = reader.ReadUInt16();
-            InternalFileAttributes = reader.ReadUInt16();
-            ExternalFileAttributes = reader.ReadUInt32();
-            RelativeOffsetOfEntryHeader = reader.ReadUInt32();
+            Version = await stream.ReadUInt16(cancellationToken);
+            VersionNeededToExtract = await stream.ReadUInt16(cancellationToken);
+            Flags = (HeaderFlags)await stream.ReadUInt16(cancellationToken);
+            CompressionMethod = (ZipCompressionMethod)await stream.ReadUInt16(cancellationToken);
+            LastModifiedTime = await stream.ReadUInt16(cancellationToken);
+            LastModifiedDate = await stream.ReadUInt16(cancellationToken);
+            Crc = await stream.ReadUInt32(cancellationToken);
+            CompressedSize = await stream.ReadUInt32(cancellationToken);
+            UncompressedSize = await stream.ReadUInt32(cancellationToken);
+            ushort nameLength = await stream.ReadUInt16(cancellationToken);
+            ushort extraLength = await stream.ReadUInt16(cancellationToken);
+            ushort commentLength = await stream.ReadUInt16(cancellationToken);
+            DiskNumberStart = await stream.ReadUInt16(cancellationToken);
+            InternalFileAttributes = await stream.ReadUInt16(cancellationToken);
+            ExternalFileAttributes = await stream.ReadUInt32(cancellationToken);
+            RelativeOffsetOfEntryHeader = await stream.ReadUInt32(cancellationToken);
+
+            byte[] name = await stream.ReadBytes(nameLength, cancellationToken);
+            byte[] extra = await stream.ReadBytes(extraLength, cancellationToken);
+            byte[] comment = await stream.ReadBytes(commentLength, cancellationToken);
 
-            byte[] name = reader.ReadBytes(nameLength);
-            byte[] extra = reader.ReadBytes(extraLength);
-            byte[] comment = reader.ReadBytes(commentLength);
-            
             // According to .ZIP File Format Specification
             //
             // For example: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
@@ -40,7 +42,7 @@ namespace SharpCompress.Common.Zip.Headers
             // Bit 11: Language encoding flag (EFS).  If this bit is set,
             //         the filename and comment fields for this file
             //         MUST be encoded using UTF-8. (see APPENDIX D)
-            
+
             if (Flags.HasFlag(HeaderFlags.Efs))
             {
                 Name = ArchiveEncoding.DecodeUTF8(name);

src/SharpCompress/Common/Zip/Headers/IgnoreHeader.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -9,8 +11,9 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
+            return new();
         }
     }
 }

src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs

@@ -1,5 +1,7 @@
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -10,21 +12,21 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override async ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
-            Version = reader.ReadUInt16();
-            Flags = (HeaderFlags)reader.ReadUInt16();
-            CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-            LastModifiedTime = reader.ReadUInt16();
-            LastModifiedDate = reader.ReadUInt16();
-            Crc = reader.ReadUInt32();
-            CompressedSize = reader.ReadUInt32();
-            UncompressedSize = reader.ReadUInt32();
-            ushort nameLength = reader.ReadUInt16();
-            ushort extraLength = reader.ReadUInt16();
-            byte[] name = reader.ReadBytes(nameLength);
-            byte[] extra = reader.ReadBytes(extraLength);
-            
+            Version = await stream.ReadUInt16(cancellationToken);
+            Flags = (HeaderFlags)await stream.ReadUInt16(cancellationToken);
+            CompressionMethod = (ZipCompressionMethod)await stream.ReadUInt16(cancellationToken);
+            LastModifiedTime = await stream.ReadUInt16(cancellationToken);
+            LastModifiedDate = await stream.ReadUInt16(cancellationToken);
+            Crc = await stream.ReadUInt32(cancellationToken);
+            CompressedSize = await stream.ReadUInt32(cancellationToken);
+            UncompressedSize = await stream.ReadUInt32(cancellationToken);
+            ushort nameLength = await stream.ReadUInt16(cancellationToken);
+            ushort extraLength = await stream.ReadUInt16(cancellationToken);
+            byte[] name = await stream.ReadBytes(nameLength, cancellationToken);
+            byte[] extra = await stream.ReadBytes(extraLength, cancellationToken);
+
             // According to .ZIP File Format Specification
             //
             // For example: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
@@ -32,7 +34,7 @@ namespace SharpCompress.Common.Zip.Headers
             // Bit 11: Language encoding flag (EFS).  If this bit is set,
             //         the filename and comment fields for this file
             //         MUST be encoded using UTF-8. (see APPENDIX D)
-            
+
             if (Flags.HasFlag(HeaderFlags.Efs))
             {
                 Name = ArchiveEncoding.DecodeUTF8(name);
@@ -41,7 +43,7 @@ namespace SharpCompress.Common.Zip.Headers
             {
                 Name = ArchiveEncoding.Decode(name);
             }
-            
+
             LoadExtra(extra);
 
             var unicodePathExtra = Extra.FirstOrDefault(u => u.Type == ExtraDataType.UnicodePathExtraField);

src/SharpCompress/Common/Zip/Headers/LocalEntryHeaderExtraFactory.cs

@@ -1,6 +1,4 @@
-#nullable disable
-
-using System;
+using System;
 using System.Buffers.Binary;
 using System.Text;
 
@@ -20,13 +18,25 @@ namespace SharpCompress.Common.Zip.Headers
 
     internal class ExtraData
     {
-        internal ExtraDataType Type { get; set; }
-        internal ushort Length { get; set; }
-        internal byte[] DataBytes { get; set; }
+        public ExtraData(ExtraDataType type, ushort length, byte[] dataBytes)
+        {
+            Type = type;
+            Length = length;
+            DataBytes = dataBytes;
+        }
+
+        internal ExtraDataType Type { get; }
+        internal ushort Length { get; }
+        internal byte[] DataBytes { get; }
     }
 
-    internal class ExtraUnicodePathExtraField : ExtraData
+    internal sealed class ExtraUnicodePathExtraField : ExtraData
     {
+        public ExtraUnicodePathExtraField(ExtraDataType type, ushort length, byte[] dataBytes)
+            : base(type, length, dataBytes)
+        {
+        }
+
         internal byte Version => DataBytes[0];
 
         internal byte[] NameCrc32
@@ -51,64 +61,45 @@ namespace SharpCompress.Common.Zip.Headers
         }
     }
 
-    internal class Zip64ExtendedInformationExtraField : ExtraData
+    internal sealed class Zip64ExtendedInformationExtraField : ExtraData
     {
-
         public Zip64ExtendedInformationExtraField(ExtraDataType type, ushort length, byte[] dataBytes)
+            : base(type, length, dataBytes)
         {
-            Type = type;
-            Length = length;
-            DataBytes = dataBytes;
             Process();
         }
 
-        //From the spec values are only in the extradata if the standard
-        //value is set to 0xFFFF, but if one of the sizes are present, both are.
-        //Hence if length == 4 volume only
-        //      if length == 8 offset only
-        //      if length == 12 offset + volume
-        //      if length == 16 sizes only
-        //      if length == 20 sizes + volume
-        //      if length == 24 sizes + offset
-        //      if length == 28 everything.
-        //It is unclear how many of these are used in the wild.
-
         private void Process()
         {
+            if (DataBytes.Length >= 8)
+            {
+                UncompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
+            }
+
+            if (DataBytes.Length >= 16)
+            {
+                CompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(8));
+            }
+
+            if (DataBytes.Length >= 24)
+            {
+                RelativeOffsetOfEntryHeader = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(16));
+            }
+
+            if (DataBytes.Length >= 28)
+            {
+                VolumeNumber = BinaryPrimitives.ReadUInt32LittleEndian(DataBytes.AsSpan(24));
+            }
+
             switch (DataBytes.Length)
             {
-                case 4:
-                    VolumeNumber = BinaryPrimitives.ReadUInt32LittleEndian(DataBytes);
-                    return;
                 case 8:
-                    RelativeOffsetOfEntryHeader = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    return;
-                case 12:
-                    RelativeOffsetOfEntryHeader = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    VolumeNumber = BinaryPrimitives.ReadUInt32LittleEndian(DataBytes.AsSpan(8));
-                    return;
                 case 16:
-                    UncompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    CompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(8));
-                    return;
-                case 20:
-                    UncompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    CompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(8));
-                    VolumeNumber = BinaryPrimitives.ReadUInt32LittleEndian(DataBytes.AsSpan(16));
-                    return;
                 case 24:
-                    UncompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    CompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(8));
-                    RelativeOffsetOfEntryHeader = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(16));
-                    return;
                 case 28:
-                    UncompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes);
-                    CompressedSize = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(8));
-                    RelativeOffsetOfEntryHeader = BinaryPrimitives.ReadInt64LittleEndian(DataBytes.AsSpan(16));
-                    VolumeNumber = BinaryPrimitives.ReadUInt32LittleEndian(DataBytes.AsSpan(24));
-                    return;
+                    break;
                 default:
-                throw new ArchiveException("Unexpected size of of Zip64 extended information extra field");
+                    throw new ArchiveException($"Unexpected size of of Zip64 extended information extra field: {DataBytes.Length}");
             }
         }
 
@@ -122,30 +113,12 @@ namespace SharpCompress.Common.Zip.Headers
     {
         internal static ExtraData Create(ExtraDataType type, ushort length, byte[] extraData)
         {
-            switch (type)
+            return type switch
             {
-                case ExtraDataType.UnicodePathExtraField:
-                    return new ExtraUnicodePathExtraField
-                           {
-                               Type = type,
-                               Length = length,
-                               DataBytes = extraData
-                           };
-                case ExtraDataType.Zip64ExtendedInformationExtraField:
-                    return new Zip64ExtendedInformationExtraField
-                            (
-                                type,
-                                length,
-                                extraData
-                           );
-                default:
-                    return new ExtraData
-                           {
-                               Type = type,
-                               Length = length,
-                               DataBytes = extraData
-                           };
-            }
+                ExtraDataType.UnicodePathExtraField => new ExtraUnicodePathExtraField(type, length, extraData),
+                ExtraDataType.Zip64ExtendedInformationExtraField => new Zip64ExtendedInformationExtraField(type, length, extraData),
+                _ => new ExtraData(type, length, extraData)
+            };
         }
     }
 }

src/SharpCompress/Common/Zip/Headers/SplitHeader.cs

@@ -1,5 +1,7 @@
 using System;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -10,7 +12,7 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
             throw new NotImplementedException();
         }

src/SharpCompress/Common/Zip/Headers/Zip64DirectoryEndHeader.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -9,18 +11,18 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override async ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
-            SizeOfDirectoryEndRecord = (long)reader.ReadUInt64();
-            VersionMadeBy = reader.ReadUInt16();
-            VersionNeededToExtract = reader.ReadUInt16();
-            VolumeNumber = reader.ReadUInt32();
-            FirstVolumeWithDirectory = reader.ReadUInt32();
-            TotalNumberOfEntriesInDisk = (long)reader.ReadUInt64();
-            TotalNumberOfEntries = (long)reader.ReadUInt64();
-            DirectorySize = (long)reader.ReadUInt64();
-            DirectoryStartOffsetRelativeToDisk = (long)reader.ReadUInt64();
-            DataSector = reader.ReadBytes((int)(SizeOfDirectoryEndRecord - SIZE_OF_FIXED_HEADER_DATA_EXCEPT_SIGNATURE_AND_SIZE_FIELDS));
+            SizeOfDirectoryEndRecord = (long)await stream.ReadUInt64(cancellationToken);
+            VersionMadeBy = await stream.ReadUInt16(cancellationToken);
+            VersionNeededToExtract = await stream.ReadUInt16(cancellationToken);
+            VolumeNumber = await stream.ReadUInt32(cancellationToken);
+            FirstVolumeWithDirectory = await stream.ReadUInt32(cancellationToken);
+            TotalNumberOfEntriesInDisk = (long)await stream.ReadUInt64(cancellationToken);
+            TotalNumberOfEntries = (long)await stream.ReadUInt64(cancellationToken);
+            DirectorySize = (long)await stream.ReadUInt64(cancellationToken);
+            DirectoryStartOffsetRelativeToDisk = (long)await stream.ReadUInt64(cancellationToken);
+            DataSector = await stream.ReadBytes((int)(SizeOfDirectoryEndRecord - SIZE_OF_FIXED_HEADER_DATA_EXCEPT_SIGNATURE_AND_SIZE_FIELDS), cancellationToken);
         }
 
         private const int SIZE_OF_FIXED_HEADER_DATA_EXCEPT_SIGNATURE_AND_SIZE_FIELDS = 44;

src/SharpCompress/Common/Zip/Headers/Zip64DirectoryEndLocatorHeader.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -9,11 +11,11 @@ namespace SharpCompress.Common.Zip.Headers
         {
         }
 
-        internal override void Read(BinaryReader reader)
+        internal override async ValueTask Read(Stream stream, CancellationToken cancellationToken)
         {
-            FirstVolumeWithDirectory = reader.ReadUInt32();
-            RelativeOffsetOfTheEndOfDirectoryRecord = (long)reader.ReadUInt64();
-            TotalNumberOfVolumes = reader.ReadUInt32();
+            FirstVolumeWithDirectory = await stream.ReadUInt32(cancellationToken);
+            RelativeOffsetOfTheEndOfDirectoryRecord = (long)await stream.ReadUInt64(cancellationToken);
+            TotalNumberOfVolumes = await stream.ReadUInt32(cancellationToken);
         }
 
         public uint FirstVolumeWithDirectory { get; private set; }

src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs

@@ -20,7 +20,7 @@ namespace SharpCompress.Common.Zip.Headers
         {
             get
             {
-                if (Name.EndsWith("/"))
+                if (Name.EndsWith('/'))
                 {
                     return true;
                 }
@@ -28,7 +28,7 @@ namespace SharpCompress.Common.Zip.Headers
                 //.NET Framework 4.5 : System.IO.Compression::CreateFromDirectory() probably writes backslashes to headers
                 return CompressedSize == 0
                        && UncompressedSize == 0
-                       && Name.EndsWith("\\");
+                       && Name.EndsWith('\\');
             }
         }
 

src/SharpCompress/Common/Zip/Headers/ZipHeader.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -12,7 +14,7 @@ namespace SharpCompress.Common.Zip.Headers
 
         internal ZipHeaderType ZipHeaderType { get; }
 
-        internal abstract void Read(BinaryReader reader);
+        internal abstract ValueTask Read(Stream stream, CancellationToken cancellationToken);
 
         internal bool HasData { get; set; }
     }

src/SharpCompress/Common/Zip/PkwareTraditionalEncryptionData.cs

@@ -7,7 +7,7 @@ namespace SharpCompress.Common.Zip
     internal class PkwareTraditionalEncryptionData
     {
         private static readonly CRC32 CRC32 = new CRC32();
-        private readonly UInt32[] _keys = {0x12345678, 0x23456789, 0x34567890};
+        private readonly UInt32[] _keys = { 0x12345678, 0x23456789, 0x34567890 };
         private readonly ArchiveEncoding _archiveEncoding;
 
         private PkwareTraditionalEncryptionData(string password, ArchiveEncoding archiveEncoding)

src/SharpCompress/Common/Zip/SeekableZipFilePart.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.IO;
 
@@ -17,22 +19,22 @@ namespace SharpCompress.Common.Zip
             _directoryEntryHeader = header;
         }
 
-        internal override Stream GetCompressedStream()
+        internal override async ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
             if (!_isLocalHeaderLoaded)
             {
-                LoadLocalHeader();
+                await LoadLocalHeader(cancellationToken);
                 _isLocalHeaderLoaded = true;
             }
-            return base.GetCompressedStream();
+            return await base.GetCompressedStreamAsync(cancellationToken);
         }
 
         internal string? Comment => ((DirectoryEntryHeader)Header).Comment;
 
-        private void LoadLocalHeader()
+        private async ValueTask LoadLocalHeader(CancellationToken cancellationToken)
         {
             bool hasData = Header.HasData;
-            Header = _headerFactory.GetLocalHeader(BaseStream, ((DirectoryEntryHeader)Header));
+            Header = await _headerFactory.GetLocalHeader(BaseStream, (DirectoryEntryHeader)Header, cancellationToken);
             Header.HasData = hasData;
         }
 

src/SharpCompress/Common/Zip/SeekableZipHeaderFactory.cs

@@ -1,14 +1,22 @@
 using System;
+using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
+using SharpCompress.Compressors.Xz;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip
 {
     internal sealed class SeekableZipHeaderFactory : ZipHeaderFactory
     {
-        private const int MAX_ITERATIONS_FOR_DIRECTORY_HEADER = 4096;
+        private const int MINIMUM_EOCD_LENGTH = 22;
+        private const int ZIP64_EOCD_LENGTH = 20;
+        // Comment may be within 64kb + structure 22 bytes
+        private const int MAX_SEARCH_LENGTH_FOR_EOCD = 65557;
         private bool _zip64;
 
         internal SeekableZipHeaderFactory(string? password, ArchiveEncoding archiveEncoding)
@@ -16,43 +24,51 @@ namespace SharpCompress.Common.Zip
         {
         }
 
-        internal IEnumerable<ZipHeader> ReadSeekableHeader(Stream stream)
+        internal async IAsyncEnumerable<ZipHeader> ReadSeekableHeader(Stream stream, [EnumeratorCancellation]CancellationToken cancellationToken)
         {
-            var reader = new BinaryReader(stream);
+            await SeekBackToHeaderAsync(stream);
 
-            SeekBackToHeader(stream, reader, DIRECTORY_END_HEADER_BYTES);
+            var eocd_location = stream.Position;
             var entry = new DirectoryEndHeader();
-            entry.Read(reader);
+            await entry.Read(stream, cancellationToken);
 
             if (entry.IsZip64)
             {
                 _zip64 = true;
-                SeekBackToHeader(stream, reader, ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR);
+
+                // ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR should be before the EOCD
+                stream.Seek(eocd_location - ZIP64_EOCD_LENGTH - 4, SeekOrigin.Begin);
+                uint zip64_locator = await stream.ReadUInt32(cancellationToken);
+                if( zip64_locator != ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR )
+                {
+                    throw new ArchiveException("Failed to locate the Zip64 Directory Locator");
+                }
+
                 var zip64Locator = new Zip64DirectoryEndLocatorHeader();
-                zip64Locator.Read(reader);
+                await zip64Locator.Read(stream, cancellationToken);
 
                 stream.Seek(zip64Locator.RelativeOffsetOfTheEndOfDirectoryRecord, SeekOrigin.Begin);
-                uint zip64Signature = reader.ReadUInt32();
+                uint zip64Signature = await stream.ReadUInt32(cancellationToken);
                 if (zip64Signature != ZIP64_END_OF_CENTRAL_DIRECTORY)
                 {
                     throw new ArchiveException("Failed to locate the Zip64 Header");
                 }
 
                 var zip64Entry = new Zip64DirectoryEndHeader();
-                zip64Entry.Read(reader);
+                await zip64Entry.Read(stream, cancellationToken);
                 stream.Seek(zip64Entry.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
             }
             else
             {
-                stream.Seek(entry.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
+                stream.Seek(entry.DirectoryStartOffsetRelativeToDisk ?? 0, SeekOrigin.Begin);
             }
 
             long position = stream.Position;
             while (true)
             {
                 stream.Position = position;
-                uint signature = reader.ReadUInt32();
-                var nextHeader = ReadHeader(signature, reader, _zip64);
+                uint signature = await stream.ReadUInt32(cancellationToken);
+                var nextHeader = await ReadHeader(signature, stream, cancellationToken, _zip64);
                 position = stream.Position;
 
                 if (nextHeader is null)
@@ -73,35 +89,58 @@ namespace SharpCompress.Common.Zip
             }
         }
 
-        private static void SeekBackToHeader(Stream stream, BinaryReader reader, uint headerSignature)
+        private static bool IsMatch (Span<byte> haystack, int position, byte[] needle)
         {
-            long offset = 0;
-            uint signature;
-            int iterationCount = 0;
-            do
+            for( int i = 0; i < needle.Length; i++ )
             {
-                if ((stream.Length + offset) - 4 < 0)
+                if( haystack[ position + i ] != needle[ i ] )
                 {
-                    throw new ArchiveException("Failed to locate the Zip Header");
-                }
-                stream.Seek(offset - 4, SeekOrigin.End);
-                signature = reader.ReadUInt32();
-                offset--;
-                iterationCount++;
-                if (iterationCount > MAX_ITERATIONS_FOR_DIRECTORY_HEADER)
-                {
-                    throw new ArchiveException("Could not find Zip file Directory at the end of the file.  File may be corrupted.");
+                    return false;
                 }
             }
-            while (signature != headerSignature);
+
+            return true;
+        }
+        private static async ValueTask SeekBackToHeaderAsync(Stream stream)
+        {
+            // Minimum EOCD length
+            if (stream.Length < MINIMUM_EOCD_LENGTH)
+            {
+                throw new ArchiveException("Could not find Zip file Directory at the end of the file. File may be corrupted.");
+            }
+
+            int len = stream.Length < MAX_SEARCH_LENGTH_FOR_EOCD ? (int)stream.Length : MAX_SEARCH_LENGTH_FOR_EOCD;
+            // We search for marker in reverse to find the first occurance
+            byte[] needle = { 0x06, 0x05, 0x4b, 0x50 };
+
+            stream.Seek(-len, SeekOrigin.End);
+
+            using var rented = MemoryPool<byte>.Shared.Rent(len);
+            var buffer = rented.Memory.Slice(0, len);
+            await stream.ReadAsync(buffer);
+
+            // Search in reverse
+            buffer.Span.Reverse();
+
+            var max_search_area = len - MINIMUM_EOCD_LENGTH;
+
+            for( int pos_from_end = 0; pos_from_end < max_search_area; ++pos_from_end)
+            {
+                if( IsMatch( buffer.Span, pos_from_end, needle) )
+                {
+                    stream.Seek(-pos_from_end, SeekOrigin.End);
+                    return;
+                }
+            }
+
+            throw new ArchiveException("Failed to locate the Zip Header");
         }
 
-        internal LocalEntryHeader GetLocalHeader(Stream stream, DirectoryEntryHeader directoryEntryHeader)
+        internal async ValueTask<LocalEntryHeader> GetLocalHeader(Stream stream, DirectoryEntryHeader directoryEntryHeader, CancellationToken cancellationToken)
         {
             stream.Seek(directoryEntryHeader.RelativeOffsetOfEntryHeader, SeekOrigin.Begin);
-            BinaryReader reader = new BinaryReader(stream);
-            uint signature = reader.ReadUInt32();
-            var localEntryHeader = ReadHeader(signature, reader, _zip64) as LocalEntryHeader;
+            uint signature = await stream.ReadUInt32(cancellationToken);
+            var localEntryHeader = await ReadHeader(signature, stream, cancellationToken, _zip64) as LocalEntryHeader;
             if (localEntryHeader is null)
             {
                 throw new InvalidOperationException();

src/SharpCompress/Common/Zip/StreamingZipFilePart.cs

@@ -1,4 +1,6 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.IO;
@@ -19,13 +21,13 @@ namespace SharpCompress.Common.Zip
             return Header.PackedStream;
         }
 
-        internal override Stream GetCompressedStream()
+        internal override async ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
             if (!Header.HasData)
             {
                 return Stream.Null;
             }
-            _decompressionStream = CreateDecompressionStream(GetCryptoStream(CreateBaseStream()), Header.CompressionMethod);
+            _decompressionStream = await CreateDecompressionStream(GetCryptoStream(CreateBaseStream()), Header.CompressionMethod, cancellationToken);
             if (LeaveStreamOpen)
             {
                 return new NonDisposingStream(_decompressionStream);
@@ -33,17 +35,17 @@ namespace SharpCompress.Common.Zip
             return _decompressionStream;
         }
 
-        internal BinaryReader FixStreamedFileLocation(ref RewindableStream rewindableStream)
+        internal async ValueTask FixStreamedFileLocation(RewindableStream rewindableStream, CancellationToken cancellationToken)
         {
             if (Header.IsDirectory)
             {
-                return new BinaryReader(rewindableStream);
+                return;
             }
             if (Header.HasData && !Skipped)
             {
-                _decompressionStream ??= GetCompressedStream();
-                
-                _decompressionStream.Skip();
+                _decompressionStream ??= await GetCompressedStreamAsync(cancellationToken);
+
+                await _decompressionStream.SkipAsync(cancellationToken);
 
                 if (_decompressionStream is DeflateStream deflateStream)
                 {
@@ -51,9 +53,7 @@ namespace SharpCompress.Common.Zip
                 }
                 Skipped = true;
             }
-            var reader = new BinaryReader(rewindableStream);
             _decompressionStream = null;
-            return reader;
         }
     }
 }

src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
-using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.IO;
 
@@ -12,44 +13,40 @@ namespace SharpCompress.Common.Zip
         {
         }
 
-        internal IEnumerable<ZipHeader> ReadStreamHeader(Stream stream)
+        internal async IAsyncEnumerable<ZipHeader> ReadStreamHeader(RewindableStream rewindableStream, [EnumeratorCancellation] CancellationToken cancellationToken)
         {
-            RewindableStream rewindableStream;
-
-            if (stream is RewindableStream rs)
-            {
-                rewindableStream = rs;
-            }
-            else
-            {
-                rewindableStream = new RewindableStream(stream);
-            }
             while (true)
             {
                 ZipHeader? header;
-                BinaryReader reader = new BinaryReader(rewindableStream);
                 if (_lastEntryHeader != null &&
                     (FlagUtility.HasFlag(_lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor) || _lastEntryHeader.IsZip64))
                 {
-                    reader = ((StreamingZipFilePart)_lastEntryHeader.Part).FixStreamedFileLocation(ref rewindableStream);
+                    await ((StreamingZipFilePart)_lastEntryHeader.Part).FixStreamedFileLocation(rewindableStream, cancellationToken);
                     long? pos = rewindableStream.CanSeek ? (long?)rewindableStream.Position : null;
-                    uint crc = reader.ReadUInt32();
+                    uint crc = await rewindableStream.ReadUInt32(cancellationToken);
                     if (crc == POST_DATA_DESCRIPTOR)
                     {
-                        crc = reader.ReadUInt32();
+                        crc = await rewindableStream.ReadUInt32(cancellationToken);
                     }
                     _lastEntryHeader.Crc = crc;
-                    _lastEntryHeader.CompressedSize = reader.ReadUInt32();
-                    _lastEntryHeader.UncompressedSize = reader.ReadUInt32();
+                    _lastEntryHeader.CompressedSize = await rewindableStream.ReadUInt32(cancellationToken);
+                    _lastEntryHeader.UncompressedSize = await rewindableStream.ReadUInt32(cancellationToken);
                     if (pos.HasValue)
                     {
                         _lastEntryHeader.DataStartPosition = pos - _lastEntryHeader.CompressedSize;
                     }
                 }
                 _lastEntryHeader = null;
-                uint headerBytes = reader.ReadUInt32();
-                header = ReadHeader(headerBytes, reader);
-                if (header is null) { yield break; }
+                var headerBytes = await rewindableStream.ReadUInt32OrNull(cancellationToken);
+                if (headerBytes is null)
+                {
+                    yield break;
+                }
+                header = await ReadHeader(headerBytes.Value, rewindableStream, cancellationToken);
+                if (header is null)
+                {
+                    yield break;
+                }
 
                 //entry could be zero bytes so we need to know that.
                 if (header.ZipHeaderType == ZipHeaderType.LocalEntry)
@@ -57,21 +54,21 @@ namespace SharpCompress.Common.Zip
                     var local_header = ((LocalEntryHeader)header);
 
                     // If we have CompressedSize, there is data to be read
-                    if( local_header.CompressedSize > 0 )
+                    if (local_header.CompressedSize > 0)
                     {
                         header.HasData = true;
                     } // Check if zip is streaming ( Length is 0 and is declared in PostDataDescriptor )
-                    else if( local_header.Flags.HasFlag(HeaderFlags.UsePostDataDescriptor) )
+                    else if (local_header.Flags.HasFlag(HeaderFlags.UsePostDataDescriptor))
                     {
                         bool isRecording = rewindableStream.IsRecording;
                         if (!isRecording)
                         {
                             rewindableStream.StartRecording();
                         }
-                        uint nextHeaderBytes = reader.ReadUInt32();
+                        uint nextHeaderBytes = await rewindableStream.ReadUInt32(cancellationToken);
 
                         // Check if next data is PostDataDescriptor, streamed file with 0 length
-                        header.HasData = !IsHeader(nextHeaderBytes);
+                        header.HasData = nextHeaderBytes != POST_DATA_DESCRIPTOR;
                         rewindableStream.Rewind(!isRecording);
                     }
                     else // We are not streaming and compressed size is 0, we have no data

src/SharpCompress/Common/Zip/WinzipAesCryptoStream.cs

@@ -75,7 +75,7 @@ namespace SharpCompress.Common.Zip
             if (disposing)
             {
                 //read out last 10 auth bytes
-                var ten = new byte[10];
+                Span<byte> ten = stackalloc byte[10];
                 _stream.ReadFully(ten);
                 _stream.Dispose();
             }

src/SharpCompress/Common/Zip/WinzipAesEncryptionData.cs

@@ -33,8 +33,10 @@ namespace SharpCompress.Common.Zip
 
         private int KeySizeInBytes
         {
-            get { return KeyLengthInBytes(_keySize);
-}
+            get
+            {
+                return KeyLengthInBytes(_keySize);
+            }
         }
 
         internal static int KeyLengthInBytes(WinzipAesKeySize keySize)

src/SharpCompress/Common/Zip/ZipEntry.cs

@@ -27,33 +27,33 @@ namespace SharpCompress.Common.Zip
                 switch (_filePart.Header.CompressionMethod)
                 {
                     case ZipCompressionMethod.BZip2:
-                    {
-                        return CompressionType.BZip2;
-                    }
+                        {
+                            return CompressionType.BZip2;
+                        }
                     case ZipCompressionMethod.Deflate:
-                    {
-                        return CompressionType.Deflate;
-                    }
+                        {
+                            return CompressionType.Deflate;
+                        }
                     case ZipCompressionMethod.Deflate64:
-                    {
-                        return CompressionType.Deflate64;
-                    }
+                        {
+                            return CompressionType.Deflate64;
+                        }
                     case ZipCompressionMethod.LZMA:
-                    {
-                        return CompressionType.LZMA;
-                    }
+                        {
+                            return CompressionType.LZMA;
+                        }
                     case ZipCompressionMethod.PPMd:
-                    {
-                        return CompressionType.PPMd;
-                    }
+                        {
+                            return CompressionType.PPMd;
+                        }
                     case ZipCompressionMethod.None:
-                    {
-                        return CompressionType.None;
-                    }
+                        {
+                            return CompressionType.None;
+                        }
                     default:
-                    {
-                        return CompressionType.Unknown;
-                    }
+                        {
+                            return CompressionType.Unknown;
+                        }
                 }
             }
         }

src/SharpCompress/Common/Zip/ZipFilePart.cs

@@ -2,13 +2,15 @@
 using System.Buffers.Binary;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.Compressors;
 using SharpCompress.Compressors.BZip2;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.Compressors.Deflate64;
 using SharpCompress.Compressors.LZMA;
-using SharpCompress.Compressors.PPMd;
+//using SharpCompress.Compressors.PPMd;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip
@@ -28,13 +30,13 @@ namespace SharpCompress.Common.Zip
 
         internal override string FilePartName => Header.Name;
 
-        internal override Stream GetCompressedStream()
+        internal override async ValueTask<Stream> GetCompressedStreamAsync(CancellationToken cancellationToken)
         {
             if (!Header.HasData)
             {
                 return Stream.Null;
             }
-            Stream decompressionStream = CreateDecompressionStream(GetCryptoStream(CreateBaseStream()), Header.CompressionMethod);
+            Stream decompressionStream = await CreateDecompressionStream(GetCryptoStream(CreateBaseStream()), Header.CompressionMethod, cancellationToken);
             if (LeaveStreamOpen)
             {
                 return new NonDisposingStream(decompressionStream);
@@ -55,77 +57,76 @@ namespace SharpCompress.Common.Zip
 
         protected bool LeaveStreamOpen => FlagUtility.HasFlag(Header.Flags, HeaderFlags.UsePostDataDescriptor) || Header.IsZip64;
 
-        protected Stream CreateDecompressionStream(Stream stream, ZipCompressionMethod method)
+        protected async ValueTask<Stream> CreateDecompressionStream(Stream stream, ZipCompressionMethod method, CancellationToken cancellationToken)
         {
             switch (method)
             {
                 case ZipCompressionMethod.None:
-                {
-                    return stream;
-                }
+                    {
+                        return stream;
+                    }
                 case ZipCompressionMethod.Deflate:
-                {
-                    return new DeflateStream(stream, CompressionMode.Decompress);
-                }
+                    {
+                        return new DeflateStream(stream, CompressionMode.Decompress);
+                    }
                 case ZipCompressionMethod.Deflate64:
-                {
-                    return new Deflate64Stream(stream, CompressionMode.Decompress);
-                }
+                    {
+                        return new Deflate64Stream(stream, CompressionMode.Decompress);
+                    }
                 case ZipCompressionMethod.BZip2:
-                {
-                    return new BZip2Stream(stream, CompressionMode.Decompress, false);
-                }
+                    {
+                        return await BZip2Stream.CreateAsync(stream, CompressionMode.Decompress, false, cancellationToken);
+                    }                                                                                          
                 case ZipCompressionMethod.LZMA:
-                {
-                    if (FlagUtility.HasFlag(Header.Flags, HeaderFlags.Encrypted))
                     {
-                        throw new NotSupportedException("LZMA with pkware encryption.");
+                        if (FlagUtility.HasFlag(Header.Flags, HeaderFlags.Encrypted))
+                        {
+                            throw new NotSupportedException("LZMA with pkware encryption.");
+                        }
+                        await stream.ReadUInt16(cancellationToken); //LZMA version
+                        var props = new byte[await stream.ReadUInt16(cancellationToken)];
+                        await stream.ReadAsync(props, 0, props.Length, cancellationToken);
+                        return await LzmaStream.CreateAsync(props, stream,
+                                              Header.CompressedSize > 0 ? Header.CompressedSize - 4 - props.Length : -1,
+                                              FlagUtility.HasFlag(Header.Flags, HeaderFlags.Bit1)
+                                                  ? -1
+                                                  : (long)Header.UncompressedSize,
+                                              cancellationToken: cancellationToken);
                     }
-                    var reader = new BinaryReader(stream);
-                    reader.ReadUInt16(); //LZMA version
-                    var props = new byte[reader.ReadUInt16()];
-                    reader.Read(props, 0, props.Length);
-                    return new LzmaStream(props, stream,
-                                          Header.CompressedSize > 0 ? Header.CompressedSize - 4 - props.Length : -1,
-                                          FlagUtility.HasFlag(Header.Flags, HeaderFlags.Bit1)
-                                              ? -1
-                                              : (long)Header.UncompressedSize);
-                }
-                case ZipCompressionMethod.PPMd:
+              /*  case ZipCompressionMethod.PPMd:
                 {
-                    var props = new byte[2];
-                    stream.ReadFully(props);
-                    return new PpmdStream(new PpmdProperties(props), stream, false);
-                }
+                    var props = await stream.ReadBytes(2, cancellationToken);
+                        return new PpmdStream(new PpmdProperties(props), stream, false);
+                    }  */
                 case ZipCompressionMethod.WinzipAes:
-                {
-                    ExtraData data = Header.Extra.Where(x => x.Type == ExtraDataType.WinZipAes).SingleOrDefault();
-                    if (data is null)
                     {
-                        throw new InvalidFormatException("No Winzip AES extra data found.");
-                    }
-                    if (data.Length != 7)
-                    {
-                        throw new InvalidFormatException("Winzip data length is not 7.");
-                    }
-                    ushort compressedMethod = BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes);
+                        ExtraData? data = Header.Extra.SingleOrDefault(x => x.Type == ExtraDataType.WinZipAes);
+                        if (data is null)
+                        {
+                            throw new InvalidFormatException("No Winzip AES extra data found.");
+                        }
+                        if (data.Length != 7)
+                        {
+                            throw new InvalidFormatException("Winzip data length is not 7.");
+                        }
+                        ushort compressedMethod = BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes);
 
-                    if (compressedMethod != 0x01 && compressedMethod != 0x02)
-                    {
-                        throw new InvalidFormatException("Unexpected vendor version number for WinZip AES metadata");
-                    }
+                        if (compressedMethod != 0x01 && compressedMethod != 0x02)
+                        {
+                            throw new InvalidFormatException("Unexpected vendor version number for WinZip AES metadata");
+                        }
 
-                    ushort vendorId = BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes.AsSpan(2));
-                    if (vendorId != 0x4541)
-                    {
-                        throw new InvalidFormatException("Unexpected vendor ID for WinZip AES metadata");
+                        ushort vendorId = BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes.AsSpan(2));
+                        if (vendorId != 0x4541)
+                        {
+                            throw new InvalidFormatException("Unexpected vendor ID for WinZip AES metadata");
+                        }
+                        return await CreateDecompressionStream(stream, (ZipCompressionMethod)BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes.AsSpan(5)), cancellationToken);
                     }
-                    return CreateDecompressionStream(stream, (ZipCompressionMethod)BinaryPrimitives.ReadUInt16LittleEndian(data.DataBytes.AsSpan(5)));
-                }
                 default:
-                {
-                    throw new NotSupportedException("CompressionMethod: " + Header.CompressionMethod);
-                }
+                    {
+                        throw new NotSupportedException("CompressionMethod: " + Header.CompressionMethod);
+                    }
             }
         }
 
@@ -159,23 +160,23 @@ namespace SharpCompress.Common.Zip
                     case ZipCompressionMethod.BZip2:
                     case ZipCompressionMethod.LZMA:
                     case ZipCompressionMethod.PPMd:
-                    {
-                        return new PkwareTraditionalCryptoStream(plainStream, Header.ComposeEncryptionData(plainStream), CryptoMode.Decrypt);
-                    }
+                        {
+                            return new PkwareTraditionalCryptoStream(plainStream, Header.ComposeEncryptionData(plainStream), CryptoMode.Decrypt);
+                        }
 
                     case ZipCompressionMethod.WinzipAes:
-                    {
-                        if (Header.WinzipAesEncryptionData != null)
                         {
-                            return new WinzipAesCryptoStream(plainStream, Header.WinzipAesEncryptionData, Header.CompressedSize - 10);
+                            if (Header.WinzipAesEncryptionData != null)
+                            {
+                                return new WinzipAesCryptoStream(plainStream, Header.WinzipAesEncryptionData, Header.CompressedSize - 10);
+                            }
+                            return plainStream;
                         }
-                        return plainStream;
-                    }
 
                     default:
-                    {
-                        throw new ArgumentOutOfRangeException();
-                    }
+                        {
+                            throw new ArgumentOutOfRangeException();
+                        }
 
                 }
             }

src/SharpCompress/Common/Zip/ZipHeaderFactory.cs

@@ -1,6 +1,8 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.IO;
 
@@ -30,36 +32,36 @@ namespace SharpCompress.Common.Zip
             this._archiveEncoding = archiveEncoding;
         }
 
-        protected ZipHeader? ReadHeader(uint headerBytes, BinaryReader reader, bool zip64 = false)
+        protected async ValueTask<ZipHeader?> ReadHeader(uint headerBytes, Stream stream, CancellationToken cancellationToken, bool zip64 = false)
         {
             switch (headerBytes)
             {
                 case ENTRY_HEADER_BYTES:
-                {
-                    var entryHeader = new LocalEntryHeader(_archiveEncoding);
-                    entryHeader.Read(reader);
-                    LoadHeader(entryHeader, reader.BaseStream);
+                    {
+                        var entryHeader = new LocalEntryHeader(_archiveEncoding);
+                        await entryHeader.Read(stream, cancellationToken);
+                        await LoadHeader(entryHeader, stream, cancellationToken);
 
-                    _lastEntryHeader = entryHeader;
-                    return entryHeader;
-                }
+                        _lastEntryHeader = entryHeader;
+                        return entryHeader;
+                    }
                 case DIRECTORY_START_HEADER_BYTES:
-                {
-                    var entry = new DirectoryEntryHeader(_archiveEncoding);
-                    entry.Read(reader);
-                    return entry;
-                }
+                    {
+                        var entry = new DirectoryEntryHeader(_archiveEncoding);
+                        await entry.Read(stream, cancellationToken);
+                        return entry;
+                    }
                 case POST_DATA_DESCRIPTOR:
                     {
                         if (FlagUtility.HasFlag(_lastEntryHeader!.Flags, HeaderFlags.UsePostDataDescriptor))
                         {
-                            _lastEntryHeader.Crc = reader.ReadUInt32();
-                            _lastEntryHeader.CompressedSize = zip64 ? (long)reader.ReadUInt64() : reader.ReadUInt32();
-                            _lastEntryHeader.UncompressedSize = zip64 ? (long)reader.ReadUInt64() : reader.ReadUInt32();
+                            _lastEntryHeader.Crc = await stream.ReadUInt32(cancellationToken);
+                            _lastEntryHeader.CompressedSize = zip64 ? (long)await stream.ReadUInt64(cancellationToken) : await stream.ReadUInt32(cancellationToken);
+                            _lastEntryHeader.UncompressedSize = zip64 ? (long)await stream.ReadUInt64(cancellationToken) : await stream.ReadUInt32(cancellationToken);
                         }
                         else
                         {
-                            reader.ReadBytes(zip64 ? 20 : 12);
+                            await stream.ReadBytes(zip64 ? 20 : 12, cancellationToken);
                         }
                         return null;
                     }
@@ -68,7 +70,7 @@ namespace SharpCompress.Common.Zip
                 case DIRECTORY_END_HEADER_BYTES:
                     {
                         var entry = new DirectoryEndHeader();
-                        entry.Read(reader);
+                        await entry.Read(stream, cancellationToken);
                         return entry;
                     }
                 case SPLIT_ARCHIVE_HEADER_BYTES:
@@ -78,13 +80,13 @@ namespace SharpCompress.Common.Zip
                 case ZIP64_END_OF_CENTRAL_DIRECTORY:
                     {
                         var entry = new Zip64DirectoryEndHeader();
-                        entry.Read(reader);
+                        await entry.Read(stream, cancellationToken);
                         return entry;
                     }
                 case ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR:
                     {
                         var entry = new Zip64DirectoryEndLocatorHeader();
-                        entry.Read(reader);
+                        await entry.Read(stream, cancellationToken);
                         return entry;
                     }
                 default:
@@ -110,7 +112,7 @@ namespace SharpCompress.Common.Zip
             }
         }
 
-        private void LoadHeader(ZipFileEntry entryHeader, Stream stream)
+        private async ValueTask LoadHeader(ZipFileEntry entryHeader, Stream stream, CancellationToken cancellationToken)
         {
             if (FlagUtility.HasFlag(entryHeader.Flags, HeaderFlags.Encrypted))
             {
@@ -129,15 +131,13 @@ namespace SharpCompress.Common.Zip
 
                 if (entryHeader.CompressionMethod == ZipCompressionMethod.WinzipAes)
                 {
-                    ExtraData data = entryHeader.Extra.SingleOrDefault(x => x.Type == ExtraDataType.WinZipAes);
+                    ExtraData? data = entryHeader.Extra.SingleOrDefault(x => x.Type == ExtraDataType.WinZipAes);
                     if (data != null)
                     {
                         var keySize = (WinzipAesKeySize)data.DataBytes[4];
 
-                        var salt = new byte[WinzipAesEncryptionData.KeyLengthInBytes(keySize) / 2];
-                        var passwordVerifyValue = new byte[2];
-                        stream.Read(salt, 0, salt.Length);
-                        stream.Read(passwordVerifyValue, 0, 2);
+                        var salt = await stream.ReadBytes(WinzipAesEncryptionData.KeyLengthInBytes(keySize) / 2, cancellationToken);
+                        var passwordVerifyValue = await stream.ReadBytes(2, cancellationToken);
                         entryHeader.WinzipAesEncryptionData =
                             new WinzipAesEncryptionData(keySize, salt, passwordVerifyValue, _password);
 

src/SharpCompress/Compressors/ADC/ADCBase.cs

@@ -52,32 +52,24 @@ namespace SharpCompress.Compressors.ADC
 
         private static int GetChunkSize(byte byt)
         {
-            switch (GetChunkType(byt))
+            return GetChunkType(byt) switch
             {
-                case PLAIN:
-                    return (byt & 0x7F) + 1;
-                case TWO_BYTE:
-                    return ((byt & 0x3F) >> 2) + 3;
-                case THREE_BYTE:
-                    return (byt & 0x3F) + 4;
-                default:
-                    return -1;
-            }
+                PLAIN => (byt & 0x7F) + 1,
+                TWO_BYTE => ((byt & 0x3F) >> 2) + 3,
+                THREE_BYTE => (byt & 0x3F) + 4,
+                _ => -1,
+            };
         }
 
         private static int GetOffset(ReadOnlySpan<byte> chunk)
         {
-            switch (GetChunkType(chunk[0]))
+            return GetChunkType(chunk[0]) switch
             {
-                case PLAIN:
-                    return 0;
-                case TWO_BYTE:
-                    return ((chunk[0] & 0x03) << 8) + chunk[1];
-                case THREE_BYTE:
-                    return (chunk[1] << 8) + chunk[2];
-                default:
-                    return -1;
-            }
+                PLAIN => 0,
+                TWO_BYTE => ((chunk[0] & 0x03) << 8) + chunk[1],
+                THREE_BYTE => (chunk[1] << 8) + chunk[2],
+                _ => -1,
+            };
         }
 
         /// <summary>

src/SharpCompress/Compressors/BZip2/BZip2Stream.cs

@@ -1,8 +1,13 @@
-using System.IO;
+using System;
+using System.Buffers;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.BZip2
 {
-    public class BZip2Stream : Stream
+    public sealed class BZip2Stream : AsyncStream
     {
         private readonly Stream stream;
         private bool isDisposed;
@@ -32,17 +37,14 @@ namespace SharpCompress.Compressors.BZip2
             (stream as CBZip2OutputStream)?.Finish();
         }
 
-        protected override void Dispose(bool disposing)
+        public override async ValueTask DisposeAsync()
         {
             if (isDisposed)
             {
                 return;
             }
             isDisposed = true;
-            if (disposing)
-            {
-                stream.Dispose();
-            }
+            await stream.DisposeAsync();
         }
 
         public CompressionMode Mode { get; }
@@ -53,23 +55,18 @@ namespace SharpCompress.Compressors.BZip2
 
         public override bool CanWrite => stream.CanWrite;
 
-        public override void Flush()
+        public override Task FlushAsync(CancellationToken cancellationToken)
         {
-            stream.Flush();
+            return stream.FlushAsync(cancellationToken);
         }
 
         public override long Length => stream.Length;
 
         public override long Position { get => stream.Position; set => stream.Position = value; }
 
-        public override int Read(byte[] buffer, int offset, int count)
+        public override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
         {
-            return stream.Read(buffer, offset, count);
-        }
-
-        public override int ReadByte()
-        {
-            return stream.ReadByte();
+            return stream.ReadAsync(buffer, cancellationToken);
         }
 
         public override long Seek(long offset, SeekOrigin origin)
@@ -82,14 +79,14 @@ namespace SharpCompress.Compressors.BZip2
             stream.SetLength(value);
         }
 
-        public override void Write(byte[] buffer, int offset, int count)
+        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
-            stream.Write(buffer, offset, count);
+            return stream.WriteAsync(buffer, offset, count, cancellationToken);
         }
 
-        public override void WriteByte(byte value)
+        public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = new CancellationToken())
         {
-            stream.WriteByte(value);
+            return stream.WriteAsync(buffer, cancellationToken);
         }
 
         /// <summary>
@@ -97,11 +94,12 @@ namespace SharpCompress.Compressors.BZip2
         /// </summary>
         /// <param name="stream"></param>
         /// <returns></returns>
-        public static bool IsBZip2(Stream stream)
+        public static async ValueTask<bool> IsBZip2Async(Stream stream, CancellationToken cancellationToken)
         {
-            BinaryReader br = new BinaryReader(stream);
-            byte[] chars = br.ReadBytes(2);
-            if (chars.Length < 2 || chars[0] != 'B' || chars[1] != 'Z')
+            using var rented = MemoryPool<byte>.Shared.Rent(2);
+            var chars = rented.Memory.Slice(0, 2);
+            await stream.ReadAsync(chars, cancellationToken);
+            if (chars.Length < 2 || chars.Span[0] != 'B' || chars.Span[1] != 'Z')
             {
                 return false;
             }

src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs

@@ -1,5 +1,6 @@
 #nullable disable
 
+using System;
 using System.IO;
 
 /*
@@ -835,7 +836,7 @@ namespace SharpCompress.Compressors.BZip2
 
         private void SetupBlock()
         {
-            int[] cftab = new int[257];
+            Span<int> cftab = stackalloc int[257];
             char ch;
 
             cftab[0] = 0;
@@ -854,7 +855,6 @@ namespace SharpCompress.Compressors.BZip2
                 tt[cftab[ch]] = i;
                 cftab[ch]++;
             }
-            cftab = null;
 
             tPos = tt[origPtr];
 

src/SharpCompress/Compressors/BZip2/CBZip2OutputStream.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System;
+using System.IO;
 
 /*
  * Copyright 2001,2004-2005 The Apache Software Foundation
@@ -88,9 +89,9 @@ namespace SharpCompress.Compressors.BZip2
             int nNodes, nHeap, n1, n2, i, j, k;
             bool tooLong;
 
-            int[] heap = new int[BZip2Constants.MAX_ALPHA_SIZE + 2];
-            int[] weight = new int[BZip2Constants.MAX_ALPHA_SIZE * 2];
-            int[] parent = new int[BZip2Constants.MAX_ALPHA_SIZE * 2];
+            Span<int> heap = stackalloc int[BZip2Constants.MAX_ALPHA_SIZE + 2]; // 1040 bytes
+            Span<int> weight = stackalloc int[BZip2Constants.MAX_ALPHA_SIZE * 2];  // 1040 bytes
+            Span<int> parent = stackalloc int[BZip2Constants.MAX_ALPHA_SIZE * 2];  // 1040 bytes
 
             for (i = 0; i < alphaSize; i++)
             {
@@ -603,14 +604,7 @@ namespace SharpCompress.Compressors.BZip2
             while (bsLive > 0)
             {
                 int ch = (bsBuff >> 24);
-                try
-                {
-                    bsStream.WriteByte((byte)ch); // write 8-bit
-                }
-                catch (IOException e)
-                {
-                    throw e;
-                }
+                bsStream.WriteByte((byte)ch); // write 8-bit
                 bsBuff <<= 8;
                 bsLive -= 8;
                 bytesOut++;
@@ -622,14 +616,7 @@ namespace SharpCompress.Compressors.BZip2
             while (bsLive >= 8)
             {
                 int ch = (bsBuff >> 24);
-                try
-                {
-                    bsStream.WriteByte((byte)ch); // write 8-bit
-                }
-                catch (IOException e)
-                {
-                    throw e;
-                }
+                bsStream.WriteByte((byte)ch); // write 8-bit
                 bsBuff <<= 8;
                 bsLive -= 8;
                 bytesOut++;
@@ -1328,8 +1315,8 @@ namespace SharpCompress.Compressors.BZip2
         private void MainSort()
         {
             int i, j, ss, sb;
-            int[] runningOrder = new int[256];
-            int[] copy = new int[256];
+            Span<int> runningOrder = stackalloc int[256];
+            Span<int> copy = stackalloc int[256];
             bool[] bigDone = new bool[256];
             int c1, c2;
             int numQSorted;

src/SharpCompress/Compressors/Deflate/CRC32.cs

@@ -189,7 +189,7 @@ namespace SharpCompress.Compressors.Deflate
 
         // pre-initialize the crc table for speed of lookup.
 
-        private uint gf2_matrix_times(uint[] matrix, uint vec)
+        private uint gf2_matrix_times(ReadOnlySpan<uint> matrix, uint vec)
         {
             uint sum = 0;
             int i = 0;
@@ -205,7 +205,7 @@ namespace SharpCompress.Compressors.Deflate
             return sum;
         }
 
-        private void gf2_matrix_square(uint[] square, uint[] mat)
+        private void gf2_matrix_square(Span<uint> square, Span<uint> mat)
         {
             for (int i = 0; i < 32; i++)
             {
@@ -225,8 +225,8 @@ namespace SharpCompress.Compressors.Deflate
         /// <param name="length">the length of data the CRC value was calculated on</param>
         public void Combine(int crc, int length)
         {
-            var even = new uint[32]; // even-power-of-two zeros operator
-            var odd = new uint[32]; // odd-power-of-two zeros operator
+            Span<uint> even = stackalloc uint[32]; // even-power-of-two zeros operator
+            Span<uint> odd = stackalloc uint[32]; // odd-power-of-two zeros operator
 
             if (length == 0)
             {

src/SharpCompress/Compressors/Deflate/DeflateManager.cs

@@ -70,6 +70,8 @@
 
 using System;
 
+using SharpCompress.Algorithms;
+
 namespace SharpCompress.Compressors.Deflate
 {
     internal sealed partial class DeflateManager
@@ -1685,7 +1687,7 @@ namespace SharpCompress.Compressors.Deflate
             Rfc1950BytesEmitted = false;
 
             status = (WantRfc1950HeaderBytes) ? INIT_STATE : BUSY_STATE;
-            _codec._Adler32 = Adler.Adler32(0, null, 0, 0);
+            _codec._adler32 = 1;
 
             last_flush = (int)FlushType.None;
 
@@ -1763,7 +1765,7 @@ namespace SharpCompress.Compressors.Deflate
                 throw new ZlibException("Stream error.");
             }
 
-            _codec._Adler32 = Adler.Adler32(_codec._Adler32, dictionary, 0, dictionary.Length);
+            _codec._adler32 = Adler32.Calculate(_codec._adler32, dictionary);
 
             if (length < MIN_MATCH)
             {
@@ -1850,12 +1852,12 @@ namespace SharpCompress.Compressors.Deflate
                     ////putShortMSB((int)(SharedUtils.URShift(_codec._Adler32, 16)));
                     //putShortMSB((int)((UInt64)_codec._Adler32 >> 16));
                     //putShortMSB((int)(_codec._Adler32 & 0xffff));
-                    pending[pendingCount++] = (byte)((_codec._Adler32 & 0xFF000000) >> 24);
-                    pending[pendingCount++] = (byte)((_codec._Adler32 & 0x00FF0000) >> 16);
-                    pending[pendingCount++] = (byte)((_codec._Adler32 & 0x0000FF00) >> 8);
-                    pending[pendingCount++] = (byte)(_codec._Adler32 & 0x000000FF);
+                    pending[pendingCount++] = (byte)((_codec._adler32 & 0xFF000000) >> 24);
+                    pending[pendingCount++] = (byte)((_codec._adler32 & 0x00FF0000) >> 16);
+                    pending[pendingCount++] = (byte)((_codec._adler32 & 0x0000FF00) >> 8);
+                    pending[pendingCount++] = (byte)(_codec._adler32 & 0x000000FF);
                 }
-                _codec._Adler32 = Adler.Adler32(0, null, 0, 0);
+                _codec._adler32 = 1;
             }
 
             // Flush as much pending output as possible
@@ -1968,10 +1970,10 @@ namespace SharpCompress.Compressors.Deflate
             }
 
             // Write the zlib trailer (adler32)
-            pending[pendingCount++] = (byte)((_codec._Adler32 & 0xFF000000) >> 24);
-            pending[pendingCount++] = (byte)((_codec._Adler32 & 0x00FF0000) >> 16);
-            pending[pendingCount++] = (byte)((_codec._Adler32 & 0x0000FF00) >> 8);
-            pending[pendingCount++] = (byte)(_codec._Adler32 & 0x000000FF);
+            pending[pendingCount++] = (byte)((_codec._adler32 & 0xFF000000) >> 24);
+            pending[pendingCount++] = (byte)((_codec._adler32 & 0x00FF0000) >> 16);
+            pending[pendingCount++] = (byte)((_codec._adler32 & 0x0000FF00) >> 8);
+            pending[pendingCount++] = (byte)(_codec._adler32 & 0x000000FF);
 
             //putShortMSB((int)(SharedUtils.URShift(_codec._Adler32, 16)));
             //putShortMSB((int)(_codec._Adler32 & 0xffff));

src/SharpCompress/Compressors/Deflate/DeflateStream.cs

@@ -27,10 +27,13 @@
 using System;
 using System.IO;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.Deflate
 {
-    public class DeflateStream : Stream
+    public class DeflateStream : AsyncStream
     {
         private readonly ZlibBaseStream _baseStream;
         private bool _disposed;
@@ -216,35 +219,25 @@ namespace SharpCompress.Compressors.Deflate
         /// <remarks>
         /// This may or may not result in a <c>Close()</c> call on the captive stream.
         /// </remarks>
-        protected override void Dispose(bool disposing)
+        public override async ValueTask DisposeAsync()
         {
-            try
+            if (!_disposed)
             {
-                if (!_disposed)
-                {
-                    if (disposing)
-                    {
-                        _baseStream?.Dispose();
-                    }
-                    _disposed = true;
-                }
-            }
-            finally
-            {
-                base.Dispose(disposing);
+                await _baseStream.DisposeAsync();
+                _disposed = true;
             }
         }
 
         /// <summary>
         /// Flush the stream.
         /// </summary>
-        public override void Flush()
+        public override async Task FlushAsync(CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("DeflateStream");
             }
-            _baseStream.Flush();
+            await _baseStream.FlushAsync(cancellationToken);
         }
 
         /// <summary>
@@ -273,24 +266,14 @@ namespace SharpCompress.Compressors.Deflate
         /// <param name="offset">the offset within that data array to put the first byte read.</param>
         /// <param name="count">the number of bytes to read.</param>
         /// <returns>the number of bytes actually read</returns>
-        public override int Read(byte[] buffer, int offset, int count)
+        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("DeflateStream");
             }
-            return _baseStream.Read(buffer, offset, count);
+            return await _baseStream.ReadAsync(buffer, offset, count, cancellationToken);
         }
-
-        public override int ReadByte()
-        {
-            if (_disposed)
-            {
-                throw new ObjectDisposedException("DeflateStream");
-            }
-            return _baseStream.ReadByte();
-        }
-
         /// <summary>
         /// Calling this method always throws a <see cref="NotImplementedException"/>.
         /// </summary>
@@ -340,22 +323,13 @@ namespace SharpCompress.Compressors.Deflate
         /// <param name="buffer">The buffer holding data to write to the stream.</param>
         /// <param name="offset">the offset within that data array to find the first byte to write.</param>
         /// <param name="count">the number of bytes to write.</param>
-        public override void Write(byte[] buffer, int offset, int count)
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("DeflateStream");
             }
-            _baseStream.Write(buffer, offset, count);
-        }
-
-        public override void WriteByte(byte value)
-        {
-            if (_disposed)
-            {
-                throw new ObjectDisposedException("DeflateStream");
-            }
-            _baseStream.WriteByte(value);
+            await _baseStream.WriteAsync(buffer, offset, count, cancellationToken);
         }
 
         #endregion

src/SharpCompress/Compressors/Deflate/GZipStream.cs

@@ -27,22 +27,25 @@
 // ------------------------------------------------------------------
 
 using System;
+using System.Buffers;
 using System.Buffers.Binary;
 using System.IO;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.Deflate
 {
-    public class GZipStream : Stream
+    public class GZipStream : AsyncStream
     {
-        internal static readonly DateTime UNIX_EPOCH = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
-
-        public DateTime? LastModified { get; set; }
+        private static readonly DateTime UNIX_EPOCH = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
         private string? _comment;
         private string? _fileName;
+        private DateTime? _lastModified;
 
-        internal ZlibBaseStream BaseStream;
+        private readonly ZlibBaseStream _baseStream;
         private bool _disposed;
         private bool _firstReadDone;
         private int _headerByteCount;
@@ -61,7 +64,7 @@ namespace SharpCompress.Compressors.Deflate
 
         public GZipStream(Stream stream, CompressionMode mode, CompressionLevel level, Encoding encoding)
         {
-            BaseStream = new ZlibBaseStream(stream, mode, level, ZlibStreamFlavor.GZIP, encoding);
+            _baseStream = new ZlibBaseStream(stream, mode, level, ZlibStreamFlavor.GZIP, encoding);
             _encoding = encoding;
         }
 
@@ -69,27 +72,27 @@ namespace SharpCompress.Compressors.Deflate
 
         public virtual FlushType FlushMode
         {
-            get => (BaseStream._flushMode);
+            get => (_baseStream._flushMode);
             set
             {
                 if (_disposed)
                 {
                     throw new ObjectDisposedException("GZipStream");
                 }
-                BaseStream._flushMode = value;
+                _baseStream._flushMode = value;
             }
         }
 
         public int BufferSize
         {
-            get => BaseStream._bufferSize;
+            get => _baseStream._bufferSize;
             set
             {
                 if (_disposed)
                 {
                     throw new ObjectDisposedException("GZipStream");
                 }
-                if (BaseStream._workingBuffer != null)
+                if (_baseStream._workingBuffer != null)
                 {
                     throw new ZlibException("The working buffer is already set.");
                 }
@@ -99,13 +102,13 @@ namespace SharpCompress.Compressors.Deflate
                                             String.Format("Don't be silly. {0} bytes?? Use a bigger buffer, at least {1}.", value,
                                                           ZlibConstants.WorkingBufferSizeMin));
                 }
-                BaseStream._bufferSize = value;
+                _baseStream._bufferSize = value;
             }
         }
 
-        internal virtual long TotalIn => BaseStream._z.TotalBytesIn;
+        internal virtual long TotalIn => _baseStream._z.TotalBytesIn;
 
-        internal virtual long TotalOut => BaseStream._z.TotalBytesOut;
+        internal virtual long TotalOut => _baseStream._z.TotalBytesOut;
 
         #endregion
 
@@ -125,7 +128,7 @@ namespace SharpCompress.Compressors.Deflate
                 {
                     throw new ObjectDisposedException("GZipStream");
                 }
-                return BaseStream._stream.CanRead;
+                return _baseStream._stream.CanRead;
             }
         }
 
@@ -151,7 +154,7 @@ namespace SharpCompress.Compressors.Deflate
                 {
                     throw new ObjectDisposedException("GZipStream");
                 }
-                return BaseStream._stream.CanWrite;
+                return _baseStream._stream.CanWrite;
             }
         }
 
@@ -175,13 +178,13 @@ namespace SharpCompress.Compressors.Deflate
         {
             get
             {
-                if (BaseStream._streamMode == ZlibBaseStream.StreamMode.Writer)
+                if (_baseStream._streamMode == ZlibBaseStream.StreamMode.Writer)
                 {
-                    return BaseStream._z.TotalBytesOut + _headerByteCount;
+                    return _baseStream._z.TotalBytesOut + _headerByteCount;
                 }
-                if (BaseStream._streamMode == ZlibBaseStream.StreamMode.Reader)
+                if (_baseStream._streamMode == ZlibBaseStream.StreamMode.Reader)
                 {
-                    return BaseStream._z.TotalBytesIn + BaseStream._gzipHeaderByteCount;
+                    return _baseStream._z.TotalBytesIn + _baseStream._gzipHeaderByteCount;
                 }
                 return 0;
             }
@@ -195,36 +198,29 @@ namespace SharpCompress.Compressors.Deflate
         /// <remarks>
         /// This may or may not result in a <c>Close()</c> call on the captive stream.
         /// </remarks>
-        protected override void Dispose(bool disposing)
-        {
-            try
+        public override async ValueTask DisposeAsync()
             {
                 if (!_disposed)
                 {
-                    if (disposing && (BaseStream != null))
+                    if (_baseStream is not null)
                     {
-                        BaseStream.Dispose();
-                        Crc32 = BaseStream.Crc32;
+                        await _baseStream.DisposeAsync();
+                        Crc32 = _baseStream.Crc32;
                     }
                     _disposed = true;
                 }
             }
-            finally
-            {
-                base.Dispose(disposing);
-            }
-        }
 
         /// <summary>
         /// Flush the stream.
         /// </summary>
-        public override void Flush()
+        public override Task FlushAsync(CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("GZipStream");
             }
-            BaseStream.Flush();
+            return _baseStream.FlushAsync(cancellationToken);
         }
 
         /// <summary>
@@ -258,13 +254,13 @@ namespace SharpCompress.Compressors.Deflate
         /// <param name="offset">the offset within that data array to put the first byte read.</param>
         /// <param name="count">the number of bytes to read.</param>
         /// <returns>the number of bytes actually read</returns>
-        public override int Read(byte[] buffer, int offset, int count)
+        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("GZipStream");
             }
-            int n = BaseStream.Read(buffer, offset, count);
+            int n = await _baseStream.ReadAsync(buffer, offset, count, cancellationToken);
 
             // Console.WriteLine("GZipStream::Read(buffer, off({0}), c({1}) = {2}", offset, count, n);
             // Console.WriteLine( Util.FormatByteArray(buffer, offset, n) );
@@ -272,8 +268,9 @@ namespace SharpCompress.Compressors.Deflate
             if (!_firstReadDone)
             {
                 _firstReadDone = true;
-                FileName = BaseStream._GzipFileName;
-                Comment = BaseStream._GzipComment;
+                FileName = _baseStream._GzipFileName;
+                Comment = _baseStream._GzipComment;
+                LastModified = _baseStream._GzipMtime;
             }
             return n;
         }
@@ -320,19 +317,19 @@ namespace SharpCompress.Compressors.Deflate
         /// <param name="buffer">The buffer holding data to write to the stream.</param>
         /// <param name="offset">the offset within that data array to find the first byte to write.</param>
         /// <param name="count">the number of bytes to write.</param>
-        public override void Write(byte[] buffer, int offset, int count)
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException("GZipStream");
             }
-            if (BaseStream._streamMode == ZlibBaseStream.StreamMode.Undefined)
+            if (_baseStream._streamMode == ZlibBaseStream.StreamMode.Undefined)
             {
                 //Console.WriteLine("GZipStream: First write");
-                if (BaseStream._wantCompress)
+                if (_baseStream._wantCompress)
                 {
                     // first write in compression, therefore, emit the GZIP header
-                    _headerByteCount = EmitHeader();
+                    _headerByteCount = await EmitHeaderAsync();
                 }
                 else
                 {
@@ -340,7 +337,7 @@ namespace SharpCompress.Compressors.Deflate
                 }
             }
 
-            BaseStream.Write(buffer, offset, count);
+            await _baseStream.WriteAsync(buffer, offset, count, cancellationToken);
         }
 
         #endregion Stream methods
@@ -358,6 +355,20 @@ namespace SharpCompress.Compressors.Deflate
             }
         }
 
+
+        public DateTime? LastModified
+        {
+            get => _lastModified;
+            set
+            {
+                if (_disposed)
+                {
+                    throw new ObjectDisposedException(nameof(GZipStream));
+                }
+                _lastModified = value;
+            }
+        }
+
         public string? FileName
         {
             get => _fileName;
@@ -372,43 +383,34 @@ namespace SharpCompress.Compressors.Deflate
                 {
                     return;
                 }
-                if (_fileName.Contains("/"))
+                if (_fileName.Contains('/'))
                 {
                     _fileName = _fileName.Replace('/', '\\');
                 }
-                if (_fileName.EndsWith("\\"))
+                if (_fileName.EndsWith('\\'))
                 {
                     throw new InvalidOperationException("Illegal filename");
                 }
 
-                if (_fileName.Contains("\\"))
+                if (_fileName.Contains('\\'))
                 {
                     // trim any leading path
-                    int length = _fileName.Length;
-                    int num = length;
-                    while (--num >= 0)
-                    {
-                        char c = _fileName[num];
-                        if (c == '\\')
-                        {
-                            _fileName = _fileName.Substring(num + 1, length - num - 1);
-                        }
-                    }
+                    _fileName = Path.GetFileName(_fileName);
                 }
             }
         }
 
         public int Crc32 { get; private set; }
 
-        private int EmitHeader()
+        private async ValueTask<int> EmitHeaderAsync()
         {
             byte[]? commentBytes = (Comment is null) ? null
                 : _encoding.GetBytes(Comment);
             byte[]? filenameBytes = (FileName is null) ? null
                 : _encoding.GetBytes(FileName);
 
-            int cbLength = (commentBytes is null) ? 0 : commentBytes.Length + 1;
-            int fnLength = (filenameBytes is null) ? 0 : filenameBytes.Length + 1;
+            int cbLength = commentBytes?.Length + 1 ?? 0;
+            int fnLength = filenameBytes?.Length + 1 ?? 0;
 
             int bufferLength = 10 + cbLength + fnLength;
             var header = new byte[bufferLength];
@@ -434,7 +436,7 @@ namespace SharpCompress.Compressors.Deflate
             header[i++] = flag;
 
             // mtime
-            if (!LastModified.HasValue)
+            if (LastModified is null)
             {
                 LastModified = DateTime.Now;
             }
@@ -456,7 +458,7 @@ namespace SharpCompress.Compressors.Deflate
             // filename
             if (fnLength != 0)
             {
-                Array.Copy(filenameBytes, 0, header, i, fnLength - 1);
+                Array.Copy(filenameBytes!, 0, header, i, fnLength - 1);
                 i += fnLength - 1;
                 header[i++] = 0; // terminate
             }
@@ -464,12 +466,12 @@ namespace SharpCompress.Compressors.Deflate
             // comment
             if (cbLength != 0)
             {
-                Array.Copy(commentBytes, 0, header, i, cbLength - 1);
+                Array.Copy(commentBytes!, 0, header, i, cbLength - 1);
                 i += cbLength - 1;
                 header[i++] = 0; // terminate
             }
 
-            BaseStream._stream.Write(header, 0, header.Length);
+            await _baseStream._stream.WriteAsync(header, 0, header.Length);
 
             return header.Length; // bytes written
         }

src/SharpCompress/Compressors/Deflate/Inflate.cs

@@ -65,6 +65,8 @@
 
 using System;
 
+using SharpCompress.Algorithms;
+
 namespace SharpCompress.Compressors.Deflate
 {
     internal sealed class InflateBlocks
@@ -72,7 +74,7 @@ namespace SharpCompress.Compressors.Deflate
         private const int MANY = 1440;
 
         // Table for deflate from PKZIP's appnote.txt.
-        internal static readonly int[] border = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+        internal static readonly int[] border = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
 
         internal ZlibCodec _codec; // pointer back to this zlib stream
         internal int[] bb = new int[1]; // bit length tree depth
@@ -118,7 +120,7 @@ namespace SharpCompress.Compressors.Deflate
 
             if (checkfn != null)
             {
-                _codec._Adler32 = check = Adler.Adler32(0, null, 0, 0);
+                _codec._adler32 = check = 1;
             }
             return oldCheck;
         }
@@ -559,35 +561,35 @@ namespace SharpCompress.Compressors.Deflate
                         }
 
                         tb[0] = -1;
-                    {
-                        var bl = new[] {9}; // must be <= 9 for lookahead assumptions
-                        var bd = new[] {6}; // must be <= 9 for lookahead assumptions
-                        var tl = new int[1];
-                        var td = new int[1];
-
-                        t = table;
-                        t = inftree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl,
-                                                          td, hufts, _codec);
-
-                        if (t != ZlibConstants.Z_OK)
                         {
-                            if (t == ZlibConstants.Z_DATA_ERROR)
-                            {
-                                blens = null;
-                                mode = InflateBlockMode.BAD;
-                            }
-                            r = t;
+                            var bl = new[] { 9 }; // must be <= 9 for lookahead assumptions
+                            var bd = new[] { 6 }; // must be <= 9 for lookahead assumptions
+                            var tl = new int[1];
+                            var td = new int[1];
 
-                            bitb = b;
-                            bitk = k;
-                            _codec.AvailableBytesIn = n;
-                            _codec.TotalBytesIn += p - _codec.NextIn;
-                            _codec.NextIn = p;
-                            writeAt = q;
-                            return Flush(r);
+                            t = table;
+                            t = inftree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl,
+                                                              td, hufts, _codec);
+
+                            if (t != ZlibConstants.Z_OK)
+                            {
+                                if (t == ZlibConstants.Z_DATA_ERROR)
+                                {
+                                    blens = null;
+                                    mode = InflateBlockMode.BAD;
+                                }
+                                r = t;
+
+                                bitb = b;
+                                bitk = k;
+                                _codec.AvailableBytesIn = n;
+                                _codec.TotalBytesIn += p - _codec.NextIn;
+                                _codec.NextIn = p;
+                                writeAt = q;
+                                return Flush(r);
+                            }
+                            codes.Init(bl[0], bd[0], hufts, tl[0], hufts, td[0]);
                         }
-                        codes.Init(bl[0], bd[0], hufts, tl[0], hufts, td[0]);
-                    }
                         mode = InflateBlockMode.CODES;
                         goto case InflateBlockMode.CODES;
 
@@ -739,7 +741,7 @@ namespace SharpCompress.Compressors.Deflate
                 // update check information
                 if (checkfn != null)
                 {
-                    _codec._Adler32 = check = Adler.Adler32(check, window, readAt, nBytes);
+                    _codec._adler32 = check = Adler32.Calculate(check, window.AsSpan(readAt, nBytes));
                 }
 
                 // copy as far as end of window
@@ -1565,7 +1567,7 @@ namespace SharpCompress.Compressors.Deflate
         private const int PRESET_DICT = 0x20;
 
         private const int Z_DEFLATED = 8;
-        private static readonly byte[] mark = {0, 0, 0xff, 0xff};
+        private static readonly byte[] mark = { 0, 0, 0xff, 0xff };
 
         internal ZlibCodec _codec; // pointer back to this zlib stream
         internal InflateBlocks blocks; // current inflate_blocks state
@@ -1764,7 +1766,7 @@ namespace SharpCompress.Compressors.Deflate
                         _codec.AvailableBytesIn--;
                         _codec.TotalBytesIn++;
                         expectedCheck += (uint)(_codec.InputBuffer[_codec.NextIn++] & 0x000000ff);
-                        _codec._Adler32 = expectedCheck;
+                        _codec._adler32 = expectedCheck;
                         mode = InflateManagerMode.DICT0;
                         return ZlibConstants.Z_NEED_DICT;
 
@@ -1879,12 +1881,12 @@ namespace SharpCompress.Compressors.Deflate
                 throw new ZlibException("Stream error.");
             }
 
-            if (Adler.Adler32(1, dictionary, 0, dictionary.Length) != _codec._Adler32)
+            if (Adler32.Calculate(1, dictionary) != _codec._adler32)
             {
                 return ZlibConstants.Z_DATA_ERROR;
             }
 
-            _codec._Adler32 = Adler.Adler32(0, null, 0, 0);
+            _codec._adler32 = 1;
 
             if (length >= (1 << wbits))
             {

src/SharpCompress/Compressors/Deflate/Zlib.cs

@@ -374,7 +374,7 @@ namespace SharpCompress.Compressors.Deflate
         };
 
         // extra bits for each bit length code
-        internal static readonly int[] extra_blbits = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7};
+        internal static readonly int[] extra_blbits = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
 
         internal static readonly StaticTree Literals;
         internal static readonly StaticTree Distances;
@@ -405,88 +405,4 @@ namespace SharpCompress.Compressors.Deflate
             BitLengths = new StaticTree(null, extra_blbits, 0, InternalConstants.BL_CODES, InternalConstants.MAX_BL_BITS);
         }
     }
-
-    /// <summary>
-    /// Computes an Adler-32 checksum. 
-    /// </summary>
-    /// <remarks>
-    /// The Adler checksum is similar to a CRC checksum, but faster to compute, though less
-    /// reliable.  It is used in producing RFC1950 compressed streams.  The Adler checksum
-    /// is a required part of the "ZLIB" standard.  Applications will almost never need to
-    /// use this class directly.
-    /// </remarks>
-    internal sealed class Adler
-    {
-        // largest prime smaller than 65536
-        private static readonly uint BASE = 65521U;
-
-        // NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1
-        private static readonly int NMAX = 5552;
-
-        internal static uint Adler32(uint adler, byte[]? buf, int index, int len)
-        {
-            if (buf is null)
-            {
-                return 1;
-            }
-
-            uint s1 = adler & 0xffffU;
-            uint s2 = (adler >> 16) & 0xffffU;
-
-            while (len > 0)
-            {
-                int k = len < NMAX ? len : NMAX;
-                len -= k;
-                while (k >= 16)
-                {
-                    //s1 += (buf[index++] & 0xff); s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    s1 += buf[index++];
-                    s2 += s1;
-                    k -= 16;
-                }
-                if (k != 0)
-                {
-                    do
-                    {
-                        s1 += buf[index++];
-                        s2 += s1;
-                    }
-                    while (--k != 0);
-                }
-                s1 %= BASE;
-                s2 %= BASE;
-            }
-            return (s2 << 16) | s1;
-        }
-    }
 }