C#使用Brotli压缩/解压文本

Brotli

Brotli 是一种通用的无损压缩算法。它结合使用 LZ77 算法的一个现代变体（Lempel-Ziv 编码）、霍夫曼编码和二阶上下文建模来压缩数据，提供了与当前最佳通用压缩方法相媲美的压缩比。

Brotli 提供比 gzip 更好的压缩率，压缩速率也与 deflate 相当。但 brotli 压缩速度比 gzip 慢，因此 gzip 可能更适合于压缩不可缓存的内容。

System.IO.Compression.BrotliEncoder

微软出品，提供方法和静态方法，以便使用 Brotli 数据格式规范以无流、非分配和高性能的方式对数据进行编码和解码。

Demo:

public static void Test1(string str)
{
    System.IO.Compression.BrotliEncoder encoder = new System.IO.Compression.BrotliEncoder();
    var bytes = Encoding.Default.GetBytes(str);
    byte[] array = new byte[bytes.Length];
    var res = encoder.Compress(bytes, array, out int consumed, out int written, true);
    string EncodeB64Str = Convert.ToBase64String(array, 0, written);
    Console.WriteLine(EncodeB64Str);

    byte[] output = new byte[consumed];
    System.IO.Compression.BrotliDecoder decoder = new System.IO.Compression.BrotliDecoder();
    var res1 = decoder.Decompress(array, output, out int deconsumed, out int dewritten);
    var result = Encoding.Default.GetString(output,0,dewritten);
    Console.WriteLine(result);
}

Demo2(简单封装一下):

public static string BrEncoder(string str)
{
    System.IO.Compression.BrotliEncoder encoder = new System.IO.Compression.BrotliEncoder();
    var bytes = Encoding.Default.GetBytes(str);
    Span<byte> output = new Span<byte>(new byte[bytes.Length * 2]);
    var res = encoder.Compress(bytes, output, out int consumed, out int written, true);
    byte[] resultArray = new byte[written];
    Array.Copy(output.ToArray(), resultArray, written);
    return Convert.ToBase64String(resultArray);
}
public static string BrDecoder(string EncodeB64Str)
{
    var bytes = Convert.FromBase64String(EncodeB64Str);
    Span<byte> output = new Span<byte>(new byte[4096]);
    System.IO.Compression.BrotliDecoder decoder = new System.IO.Compression.BrotliDecoder();
    var res1 = decoder.Decompress(bytes, output, out int deconsumed, out int dewritten);
    var result = Encoding.Default.GetString(output);
    return result;
}

public static void Test1(string str)
{
    var res1 = BrEncoder(str);
    Console.WriteLine(res1);
    var res2 = BrDecoder(res1);
    Console.WriteLine(res2);           
}

Brotli.NET

The .net implement of the brotli algorithm,provide similar interface to Google offical API.

Quality and window control is supported.

Supported and tested on:

• Dotnet standard 2(.NET Framework [v4.6.1] and .net core [2] above)
• Windows/Linux/MacOSX
• .NET Framework v4.5
• Besides quality controll,the library use the native runtime and its performance should be better than System.IO.Compress.BrotliStream.

Demo:

using Brotli;
public static void Test3(string str)
{
    var bytes = Encoding.Default.GetBytes(str);
    var output= bytes.CompressToBrotli();
    string EncodeB64Str = Convert.ToBase64String(output);
    Console.WriteLine(EncodeB64Str);

    var bytesNeedDecode = Convert.FromBase64String(EncodeB64Str);
    var decompressedData = bytesNeedDecode.DecompressFromBrotli();
    var result = Encoding.Default.GetString(decompressedData);
    Console.WriteLine(result);
}

EasyCompressor

一个易于使用且经过优化的 .NET 压缩库，它统一了多种压缩算法，包括 LZ4、Snappy、Zstd、LZMA、Brotli、GZip、ZLib 和 Deflate。

Demo：

using EasyCompressor;
public static void Test4(string str)
{
    var _compressor = new BrotliCompressor();
    var bytes = Encoding.Default.GetBytes(str);
    var compressedBytes = _compressor.Compress(bytes);

    string EncodeB64Str = Convert.ToBase64String(compressedBytes);
    Console.WriteLine(EncodeB64Str);

    var bytesNeedDecode = Convert.FromBase64String(EncodeB64Str);
    var uncompressedBytes = _compressor.Decompress(bytesNeedDecode);
    var result = Encoding.Default.GetString(uncompressedBytes);
    Console.WriteLine(result);
}

BrotliSharpLib

BrotliSharpLib 是 Google 提供的 brotli 库/压缩代码的完整 C# 端口。它旨在成为原始 C 代码的大部分 1：1 转换。截至参考实现的 v0.6.0，所有代码都是正确的。

这些项目使用最少的 API 集来确保与各种框架（包括 .NET Standard 和 .NET Core）兼容。它还支持 little-endian 和 big-endian 架构，并针对 x86、x64 和 ARM 处理器进行了优化。
(这个能在Blazor上使用)

Demo：

public static void Test5(string str)
{
    byte[] brotliCompressedData = Encoding.Default.GetBytes(str);
    byte[] compressedBytes = BrotliSharpLib.Brotli.CompressBuffer(brotliCompressedData, 0, brotliCompressedData.Length /**, customDictionary **/);
    string EncodeB64Str = Convert.ToBase64String(compressedBytes);
    Console.WriteLine(EncodeB64Str);

    var bytesNeedDecode = Convert.FromBase64String(EncodeB64Str);
    var uncompressedBytes = BrotliSharpLib.Brotli.DecompressBuffer(bytesNeedDecode,0,bytesNeedDecode.Length);
    var result = Encoding.Default.GetString(uncompressedBytes);
    Console.WriteLine(result);
}

源码下载