Here提到了如何使用LZMA SDK压缩和解压缩文件。
这是代码:
public static void CompressFileLZMA(string inFile, string outFile)
{
Int32 dictionary = 1 << 23;
Int32 posStateBits = 2;
Int32 litContextBits = 3; // for normal files
// UInt32 litContextBits = 0; // for 32-bit data
Int32 litPosBits = 0;
// UInt32 litPosBits = 2; // for 32-bit data
Int32 algorithm = 2;
Int32 numFastBytes = 128;
string mf = "bt4";
bool eos = true;
bool stdInMode = false;
CoderPropID[] propIDs = {
CoderPropID.DictionarySize,
CoderPropID.PosStateBits,
CoderPropID.LitContextBits,
CoderPropID.LitPosBits,
CoderPropID.Algorithm,
CoderPropID.NumFastBytes,
CoderPropID.MatchFinder,
CoderPropID.EndMarker
};
object[] properties = {
(Int32)(dictionary),
(Int32)(posStateBits),
(Int32)(litContextBits),
(Int32)(litPosBits),
(Int32)(algorithm),
(Int32)(numFastBytes),
mf,
eos
};
using (FileStream inStream = new FileStream(inFile, FileMode.Open))
{
using (FileStream outStream = new FileStream(outFile, FileMode.Create))
{
SevenZip.Compression.LZMA.Encoder encoder = new SevenZip.Compression.LZMA.Encoder();
encoder.SetCoderProperties(propIDs, properties);
encoder.WriteCoderProperties(outStream);
Int64 fileSize;
if (eos || stdInMode)
fileSize = -1;
else
fileSize = inStream.Length;
for (int i = 0; i < 8; i++)
outStream.WriteByte((Byte)(fileSize >> (8 * i)));
encoder.Code(inStream, outStream, -1, -1, null);
}
}
}
public static void DecompressFileLZMA(string inFile, string outFile)
{
using (FileStream input = new FileStream(inFile, FileMode.Open))
{
using (FileStream output = new FileStream(outFile, FileMode.Create))
{
SevenZip.Compression.LZMA.Decoder decoder = new SevenZip.Compression.LZMA.Decoder();
byte[] properties = new byte[5];
if (input.Read(properties, 0, 5) != 5)
throw (new Exception("input .lzma is too short"));
decoder.SetDecoderProperties(properties);
long outSize = 0;
for (int i = 0; i < 8; i++)
{
int v = input.ReadByte();
if (v < 0)
throw (new Exception("Can't Read 1"));
outSize |= ((long)(byte)v) << (8 * i);
}
long compressedSize = input.Length - input.Position;
decoder.Code(input, output, compressedSize, outSize, null);
}
}
}
现在我需要使用SDK压缩和解压缩多个文件 我应该在代码中更改什么才能获得最佳效果?