internal int SetDictionary(byte[] dictionary)
{
int length = dictionary.Length;
int index = 0;
if (dictionary == null || status != INIT_STATE)
throw new ZlibException("Stream error.");
_codec._Adler32 = Adler.Adler32(_codec._Adler32, dictionary, 0, dictionary.Length);
if (length < MIN_MATCH)
return ZlibConstants.Z_OK;
if (length > w_size - MIN_LOOKAHEAD)
{
length = w_size - MIN_LOOKAHEAD;
index = dictionary.Length - length; // use the tail of the dictionary
}
Array.Copy(dictionary, index, window, 0, length);
strstart = length;
block_start = length;
// Insert all strings in the hash table (except for the last two bytes).
// s->lookahead stays null, so s->ins_h will be recomputed at the next
// call of fill_window.
ins_h = window[0] & 0xff;
ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
for (int n = 0; n <= length - MIN_MATCH; n++)
{
ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
prev[n & w_mask] = head[ins_h];
head[ins_h] = (short)n;
}
return ZlibConstants.Z_OK;
}