Add Adler32, Crc32, and Deflate APIs

PowerKit.Tests/Adler32Tests.cs

@@ -0,0 +1,59 @@
+using System;
+using System.IO;
+using FluentAssertions;
+using PowerKit;
+using Xunit;
+
+namespace PowerKit.Tests;
+
+public class Adler32Tests
+{
+    [Fact]
+    public void Hash_Stream_Test()
+    {
+        // Arrange
+        using var stream = new MemoryStream("Wikipedia"u8.ToArray());
+
+        // Act
+        var hash = Adler32.Hash(stream);
+
+        // Assert
+        hash.Should().Be(0x11E60398u);
+    }
+
+    [Fact]
+    public void Hash_ByteArray_Test()
+    {
+        // Arrange
+        var data = "Wikipedia"u8.ToArray();
+
+        // Act
+        var hash = Adler32.Hash(data);
+
+        // Assert
+        hash.Should().Be(0x11E60398u);
+    }
+
+    [Fact]
+    public void Hash_Span_Test()
+    {
+        // Arrange
+        var data = "Wikipedia"u8.ToArray();
+
+        // Act
+        var hash = Adler32.Hash((ReadOnlySpan<byte>)data);
+
+        // Assert
+        hash.Should().Be(0x11E60398u);
+    }
+
+    [Fact]
+    public void Hash_EmptyData_Test()
+    {
+        // Act
+        var hash = Adler32.Hash(Array.Empty<byte>());
+
+        // Assert
+        hash.Should().Be(1u);
+    }
+}

PowerKit.Tests/Crc32Tests.cs

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+using System;
+using System.IO;
+using FluentAssertions;
+using PowerKit;
+using Xunit;
+
+namespace PowerKit.Tests;
+
+public class Crc32Tests
+{
+    [Fact]
+    public void Hash_Stream_Test()
+    {
+        // Arrange
+        using var stream = new MemoryStream("123456789"u8.ToArray());
+
+        // Act
+        var hash = Crc32.Hash(stream);
+
+        // Assert
+        hash.Should().Be(0xCBF43926u);
+    }
+
+    [Fact]
+    public void Hash_ByteArray_Test()
+    {
+        // Arrange
+        var data = "123456789"u8.ToArray();
+
+        // Act
+        var hash = Crc32.Hash(data);
+
+        // Assert
+        hash.Should().Be(0xCBF43926u);
+    }
+
+    [Fact]
+    public void Hash_Span_Test()
+    {
+        // Arrange
+        var data = "123456789"u8.ToArray();
+
+        // Act
+        var hash = Crc32.Hash((ReadOnlySpan<byte>)data);
+
+        // Assert
+        hash.Should().Be(0xCBF43926u);
+    }
+
+    [Fact]
+    public void Hash_EmptyData_Test()
+    {
+        // Act
+        var hash = Crc32.Hash(Array.Empty<byte>());
+
+        // Assert
+        hash.Should().Be(0u);
+    }
+}

PowerKit.Tests/DeflateTests.cs

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+using System;
+using System.IO;
+using FluentAssertions;
+using PowerKit;
+using Xunit;
+
+namespace PowerKit.Tests;
+
+public class DeflateTests
+{
+    [Fact]
+    public void Compress_Decompress_Stream_Test()
+    {
+        // Arrange
+        var data = "hello world"u8.ToArray();
+        using var input = new MemoryStream(data);
+        using var compressed = new MemoryStream();
+        using var decompressed = new MemoryStream();
+
+        // Act
+        Deflate.Compress(input, compressed);
+        compressed.Position = 0;
+        Deflate.Decompress(compressed, decompressed);
+
+        // Assert
+        decompressed.ToArray().Should().Equal(data);
+    }
+
+    [Fact]
+    public void Compress_Decompress_ByteArray_Test()
+    {
+        // Arrange
+        var data = "hello world"u8.ToArray();
+
+        // Act
+        var compressed = Deflate.Compress(data);
+        var decompressed = Deflate.Decompress(compressed);
+
+        // Assert
+        decompressed.Should().Equal(data);
+    }
+
+    [Fact]
+    public void Compress_Decompress_Span_Test()
+    {
+        // Arrange
+        var data = "hello world"u8.ToArray();
+
+        // Act
+        var compressed = Deflate.Compress((ReadOnlySpan<byte>)data);
+        var decompressed = Deflate.Decompress((ReadOnlySpan<byte>)compressed);
+
+        // Assert
+        decompressed.Should().Equal(data);
+    }
+
+    [Fact]
+    public void Compress_Decompress_EmptyData_Test()
+    {
+        // Arrange
+        var data = Array.Empty<byte>();
+
+        // Act
+        var compressed = Deflate.Compress(data);
+        var decompressed = Deflate.Decompress(compressed);
+
+        // Assert
+        decompressed.Should().BeEmpty();
+    }
+
+    [Fact]
+    public void Compress_ProducesCompressedOutput_Test()
+    {
+        // Arrange
+        var data = new byte[1000];
+        for (var i = 0; i < data.Length; i++)
+            data[i] = (byte)(i % 4);
+
+        // Act
+        var compressed = Deflate.Compress(data);
+
+        // Assert
+        compressed.Should().HaveCountLessThan(data.Length);
+    }
+}

PowerKit/Adler32.cs

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+using System.IO;
+#if !NETFRAMEWORK || NET45_OR_GREATER
+using System;
+#endif
+
+
+namespace PowerKit;
+
+/// <summary>
+/// Provides methods for computing Adler-32 checksums.
+/// </summary>
+public static class Adler32
+{
+    private const uint Modulus = 65521;
+
+    /// <summary>
+    /// Computes the Adler-32 checksum of data read from the specified stream.
+    /// </summary>
+    public static uint Hash(Stream stream)
+    {
+        uint a = 1,
+            b = 0;
+
+        var buffer = new byte[4096];
+        int read;
+
+        while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
+        {
+            for (var i = 0; i < read; i++)
+            {
+                a = (a + buffer[i]) % Modulus;
+                b = (b + a) % Modulus;
+            }
+        }
+
+        return (b << 16) | a;
+    }
+
+    /// <summary>
+    /// Computes the Adler-32 checksum of the specified data.
+    /// </summary>
+    public static uint Hash(byte[] data)
+    {
+        using var stream = new MemoryStream(data);
+        return Hash(stream);
+    }
+
+#if !NETFRAMEWORK || NET45_OR_GREATER
+    /// <summary>
+    /// Computes the Adler-32 checksum of the specified data.
+    /// </summary>
+    public static uint Hash(ReadOnlySpan<byte> data)
+    {
+        uint a = 1,
+            b = 0;
+
+        for (var i = 0; i < data.Length; i++)
+        {
+            a = (a + data[i]) % Modulus;
+            b = (b + a) % Modulus;
+        }
+
+        return (b << 16) | a;
+    }
+#endif
+}

PowerKit/Crc32.cs

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+using System.IO;
+#if !NETFRAMEWORK || NET45_OR_GREATER
+using System;
+#endif
+
+
+namespace PowerKit;
+
+/// <summary>
+/// Provides methods for computing CRC-32 checksums.
+/// </summary>
+public static class Crc32
+{
+    private static readonly uint[] Table = GenerateTable();
+
+    private static uint[] GenerateTable()
+    {
+        var table = new uint[256];
+
+        for (var i = 0; i < 256; i++)
+        {
+            var entry = (uint)i;
+            for (var j = 0; j < 8; j++)
+            {
+                if ((entry & 1) != 0)
+                    entry = (entry >> 1) ^ 0xEDB88320u;
+                else
+                    entry >>= 1;
+            }
+
+            table[i] = entry;
+        }
+
+        return table;
+    }
+
+    /// <summary>
+    /// Computes the CRC-32 checksum of data read from the specified stream.
+    /// </summary>
+    public static uint Hash(Stream stream)
+    {
+        var crc = 0xFFFFFFFFu;
+
+        var buffer = new byte[4096];
+        int read;
+
+        while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
+        {
+            for (var i = 0; i < read; i++)
+                crc = (crc >> 8) ^ Table[(byte)(crc ^ buffer[i])];
+        }
+
+        return crc ^ 0xFFFFFFFFu;
+    }
+
+    /// <summary>
+    /// Computes the CRC-32 checksum of the specified data.
+    /// </summary>
+    public static uint Hash(byte[] data)
+    {
+        using var stream = new MemoryStream(data);
+        return Hash(stream);
+    }
+
+#if !NETFRAMEWORK || NET45_OR_GREATER
+    /// <summary>
+    /// Computes the CRC-32 checksum of the specified data.
+    /// </summary>
+    public static uint Hash(ReadOnlySpan<byte> data)
+    {
+        var crc = 0xFFFFFFFFu;
+        for (var i = 0; i < data.Length; i++)
+            crc = (crc >> 8) ^ Table[(byte)(crc ^ data[i])];
+        return crc ^ 0xFFFFFFFFu;
+    }
+#endif
+}