internal int SetDictionary(byte[] dictionary)
{
int index = 0;
int length = dictionary.Length;
if (mode != InflateManagerMode.DICT0)
{
throw new IOException("Stream error.");
}
if (Adler.Adler32(1, dictionary, 0, dictionary.Length) != _codec._Adler32)
{
return(ZConstants.Z_DATA_ERROR);
}
_codec._Adler32 = Adler.Adler32(0, null, 0, 0);
if (length >= (1 << wbits))
{
length = (1 << wbits) - 1;
index = dictionary.Length - length;
}
blocks.SetDictionary(dictionary, index, length);
mode = InflateManagerMode.BLOCKS;
return(ZConstants.Z_OK);
}
internal uint Reset()
{
uint oldCheck = check;
mode = InflateBlockMode.TYPE;
bitk = 0;
bitb = 0;
readAt = writeAt = 0;
if (checkfn != null)
{
_codec._Adler32 = check = Adler.Adler32(0, null, 0, 0);
}
return(oldCheck);
}
// Read a new buffer from the current input stream, update the adler32
// and total number of bytes read. All deflate() input goes through
// this function so some applications may wish to modify it to avoid
// allocating a large strm->next_in buffer and copying from it.
// (See also flush_pending()).
internal int read_buf(byte[] buf, int start, int size)
{
int len = AvailableBytesIn;
if (len > size)
{
len = size;
}
if (len == 0)
{
return(0);
}
AvailableBytesIn -= len;
if (dstate.WantRfc1950HeaderBytes)
{
_Adler32 = Adler.Adler32(_Adler32, InputBuffer, NextIn, len);
}
Array.Copy(InputBuffer, NextIn, buf, start, len);
NextIn += len;
TotalBytesIn += len;
return(len);
}
// copy as much as possible from the sliding window to the output area
internal int Flush(int r)
{
int nBytes;
for (int pass = 0; pass < 2; pass++)
{
if (pass == 0)
{
// compute number of bytes to copy as far as end of window
nBytes = (int)((readAt <= writeAt ? writeAt : end) - readAt);
}
else
{
// compute bytes to copy
nBytes = writeAt - readAt;
}
// workitem 8870
if (nBytes == 0)
{
if (r == ZConstants.Z_BUF_ERROR)
{
r = ZConstants.Z_OK;
}
return(r);
}
if (nBytes > _codec.AvailableBytesOut)
{
nBytes = _codec.AvailableBytesOut;
}
if (nBytes != 0 && r == ZConstants.Z_BUF_ERROR)
{
r = ZConstants.Z_OK;
}
// update counters
_codec.AvailableBytesOut -= nBytes;
_codec.TotalBytesOut += nBytes;
// update check information
if (checkfn != null)
{
_codec._Adler32 = check = Adler.Adler32(check, window, readAt, nBytes);
}
// copy as far as end of window
Array.Copy(window, readAt, _codec.OutputBuffer, _codec.NextOut, nBytes);
_codec.NextOut += nBytes;
readAt += nBytes;
// see if more to copy at beginning of window
if (readAt == end && pass == 0)
{
// wrap pointers
readAt = 0;
if (writeAt == end)
{
writeAt = 0;
}
}
else
{
pass++;
}
}
// done
return(r);
}
