基於Zlib演算法的流壓縮、字串壓縮原始碼
Zlib.net官方原始碼demo中提供了壓縮檔案的原始碼演算法。處於專案研發的需要,我需要對記憶體流進行壓縮,由於zlib.net並無相關文字幫助只能自己看原始碼解決。通過對SharpZipLib的demo研究,寫出了Zlib.net的流壓縮演算法。
中間花費了不少的時間,應為通過Stream壓縮出來的資料全是空的,呵呵,主要原因就是忽略了ZOutputStream.flush()和ZOutPutStream.close()方法。大家自己看吧。關於字串壓縮,自然是把字串塞到MemoryStream中就可以了:)
現貼原始碼如下:
現貼原始碼如下:
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.Data;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using ComponentAce.Compression.Libs.zlib;
namespace Test.Compress
...{
/**//// <summary>
/// Zlib壓縮演算法壓縮應用類
/// </summary>
public class ZlibCompress
...{
/**//// <summary>
/// 拷貝複製流位元組
/// </summary>
/// <param name="input"></param>
/// <param name="output"></param>
private static void CopyStream(Stream input, Stream output)
...{
byte[] buffer = new byte[ZipConst.ZIP_BUFFER_SIZE];
int len;
while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
...{
output.Write(buffer, 0, len);
}
output.Flush();
}
/**//// <summary>
/// 壓縮檔案
/// </summary>
/// <param name="FileName">被壓縮檔名(必須輸入絕對路徑)</param>
/// <param name="CompressedFileName">壓縮後儲存的檔名(必須輸入絕對路徑)</param>
/// <returns></returns>
public static bool CompressFile(string FileName, string CompressedFileName)
...{
bool bResult = false;
FileStream outFileStream = new FileStream(CompressedFileName, FileMode.Create);
ZOutputStream outZStream = new ZOutputStream(outFileStream, zlibConst.Z_DEFAULT_COMPRESSION);
FileStream inFileStream = new FileStream(FileName, FileMode.Open);
try
...{
CopyStream(inFileStream, outZStream);
bResult = true;
}
catch
...{
bResult = false;
}
finally
...{
outZStream.Close();
outFileStream.Close();
inFileStream.Close();
}
return bResult;
}
/**//// <summary>
/// 解壓檔案
/// </summary>
/// <param name="CompressedFileName">被解壓檔名(必須輸入絕對路徑)</param>
/// <param name="DecompressFileName">解壓後儲存的檔名(必須輸入絕對路徑)</param>
/// <returns></returns>
public static bool DecompressFile(string CompressedFileName, string DecompressFileName)
...{
bool bResult = false;
FileStream outFileStream = new FileStream(DecompressFileName, FileMode.Create);
ZOutputStream outZStream = new ZOutputStream(outFileStream);
FileStream inFileStream = new FileStream(CompressedFileName, FileMode.Open);
try
...{
CopyStream(inFileStream, outZStream);
bResult = true;
}
catch
...{
bResult = false;
}
finally
...{
outZStream.Close();
outFileStream.Close();
inFileStream.Close();
}
return bResult;
}
/**//// <summary>
/// 壓縮byte陣列資料
/// </summary>
/// <param name="SourceByte">需要被壓縮的Byte陣列資料</param>
/// <returns></returns>
public static byte[] CompressBytes(byte[] SourceByte)
...{
try
...{
MemoryStream stmInput = new MemoryStream(SourceByte);
Stream stmOutPut = ZlibCompress.CompressStream(stmInput);
byte[] bytOutPut = new byte[stmOutPut.Length];
stmOutPut.Position = 0;
stmOutPut.Read(bytOutPut, 0, bytOutPut.Length);
return bytOutPut;
}
catch
...{
return null;
}
}
/**//// <summary>
/// 解壓byte資料資料
/// </summary>
/// <param name="SourceByte">需要被解壓的byte陣列資料</param>
/// <returns></returns>
public static byte[] DecompressBytes(byte[] SourceByte)
...{
try
...{
MemoryStream stmInput = new MemoryStream(SourceByte);
Stream stmOutPut = ZlibCompress.DecompressStream(stmInput);
byte[] bytOutPut = new byte[stmOutPut.Length];
stmOutPut.Position = 0;
stmOutPut.Read(bytOutPut, 0, bytOutPut.Length);
return bytOutPut;
}
catch
...{
return null;
}
}
/**//// <summary>
/// 壓縮流
/// </summary>
/// <param name="SourceStream">需要被壓縮的流資料</param>
/// <returns></returns>
public static Stream CompressStream(Stream SourceStream)
...{
try
...{
MemoryStream stmOutTemp = new MemoryStream();
ZOutputStream outZStream = new ZOutputStream(stmOutTemp, zlibConst.Z_DEFAULT_COMPRESSION);
CopyStream(SourceStream, outZStream);
outZStream.finish();
return stmOutTemp;
}
catch
...{
return null;
}
}
/**//// <summary>
/// 解壓流
/// </summary>
/// <param name="SourceStream">需要被解縮的流資料</param>
/// <returns></returns>
public static Stream DecompressStream(Stream SourceStream)
...{
try
...{
MemoryStream stmOutput = new MemoryStream();
ZOutputStream outZStream = new ZOutputStream(stmOutput);
CopyStream(SourceStream, outZStream);
outZStream.finish();
return stmOutput;
}
catch
...{
return null;
}
}
/**//// <summary>
/// 壓縮字串
/// </summary>
/// <param name="SourceString">需要被壓縮的字串</param>
/// <returns></returns>
public static string CompressString(string SourceString)
...{
byte[] byteSource = System.Text.Encoding.UTF8.GetBytes(SourceString);
byte[] byteCompress = ZlibCompress.CompressBytes(byteSource);
if (byteCompress != null)
...{
return Convert.ToBase64String(byteCompress);
}
else
...{
return null;
}
}
/**//// <summary>
/// 解壓字串
/// </summary>
/// <param name="SourceString">需要被解壓的字串</param>
/// <returns></returns>
public static string DecompressString(string SourceString)
...{
byte[] byteSource = Convert.FromBase64String(SourceString);
byte[] byteDecompress = ZlibCompress.DecompressBytes(byteSource);
if (byteDecompress != null)
...{
return System.Text.Encoding.UTF8.GetString(byteDecompress);
}
else
...{
return null;
}
}
}
}