release/src-rt-6.x/linux/linux-2.6/scripts/squashfs/lzma/CS/7zip/Compress/LZ/LzOutWindow.cs

   1 // LzOutWindow.cs
   2
   3 namespace SevenZip.Compression.LZ
   4 {
   5         public class OutWindow
   6         {
   7                 byte[] _buffer = null;
   8                 uint _pos;
   9                 uint _windowSize = 0;
  10                 uint _streamPos;
  11                 System.IO.Stream _stream;
  12
  13                 public void Create(uint windowSize)
  14                 {
  15                         if (_windowSize != windowSize)
  16                         {
  17                                 // System.GC.Collect();
  18                                 _buffer = new byte[windowSize];
  19                         }
  20                         _windowSize = windowSize;
  21                         _pos = 0;
  22                         _streamPos = 0;
  23                 }
  24
  25                 public void Init(System.IO.Stream stream, bool solid)
  26                 {
  27                         ReleaseStream();
  28                         _stream = stream;
  29                         if (!solid)
  30                         {
  31                                 _streamPos = 0;
  32                                 _pos = 0;
  33                         }
  34                 }
  35
  36                 public void Init(System.IO.Stream stream) { Init(stream, false); }
  37
  38                 public void ReleaseStream()
  39                 {
  40                         Flush();
  41                         _stream = null;
  42                 }
  43
  44                 public void Flush()
  45                 {
  46                         uint size = _pos - _streamPos;
  47                         if (size == 0)
  48                                 return;
  49                         _stream.Write(_buffer, (int)_streamPos, (int)size);
  50                         if (_pos >= _windowSize)
  51                                 _pos = 0;
  52                         _streamPos = _pos;
  53                 }
  54
  55                 public void CopyBlock(uint distance, uint len)
  56                 {
  57                         uint pos = _pos - distance - 1;
  58                         if (pos >= _windowSize)
  59                                 pos += _windowSize;
  60                         for (; len > 0; len--)
  61                         {
  62                                 if (pos >= _windowSize)
  63                                         pos = 0;
  64                                 _buffer[_pos++] = _buffer[pos++];
  65                                 if (_pos >= _windowSize)
  66                                         Flush();
  67                         }
  68                 }
  69
  70                 public void PutByte(byte b)
  71                 {
  72                         _buffer[_pos++] = b;
  73                         if (_pos >= _windowSize)
  74                                 Flush();
  75                 }
  76
  77                 public byte GetByte(uint distance)
  78                 {
  79                         uint pos = _pos - distance - 1;
  80                         if (pos >= _windowSize)
  81                                 pos += _windowSize;
  82                         return _buffer[pos];
  83                 }
  84         }
  85 }