如何从 gzip 压缩文件转换为 Zstandard

Posted 2023-03-06

【中文标题】如何从 gzip 压缩文件转换为 Zstandard

【英文标题】：How to convert from a gzip compressed file to Zstandard

【发布时间】：2021-12-31 03:11:26

【问题描述】：

如何将 gzip 压缩文件转换为 Zstandard？这是我的尝试：

using Zstandard.Net;

public static void ConvertToZstd(string path)

    byte[] compressed = null;
    using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read))
    using (var gzipStream = new GZipStream(stream, CompressionMode.Decompress, false))
    using (var memoryStream = new MemoryStream())
    using (var compressionStream = new ZstandardStream(memoryStream, CompressionMode.Compress))
    
        compressionStream.CompressionLevel = 11;               // optional!!
        //compressionStream.CompressionDictionary = dictionary;  // optional!!
        compressionStream.Write(gzipStream, 0, gzipStream.Length);
        compressionStream.Close();
        compressed = memoryStream.ToArray();
    

【问题讨论】：

我会拆分这段代码。先解压gzip，看看能不能用，再压缩成ZstandardStream。

【参考方案1】：

public static void ConvertToZstd(string path, string outputPath)

    using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read))
    using (var gzipStream = new GZipStream(stream, CompressionMode.Decompress, false))
    using (var memoryStream = new MemoryStream())
    using (var compressionStream = new ZstandardStream(memoryStream, CompressionMode.Compress))
    
        compressionStream.CompressionLevel = 11;               // optional!!
        //compressionStream.CompressionDictionary = dictionary;  // optional!!
        gzipStream.CopyTo(compressionStream);
        compressionStream.Close();
        File.WriteAllBytes(outputPath, memoryStream.ToArray());
    

【讨论】：

你可以将File.WriteAllBytes移到内部using块之外，而不是compressionStream.Close();。