private void _fillWindow()
{
do
{
int num = window_size - lookahead - strstart;
int num2;
if (num == 0 && strstart == 0 && lookahead == 0)
{
num = w_size;
}
else if (num == -1)
{
num--;
}
else if (strstart >= w_size + w_size - MIN_LOOKAHEAD)
{
Array.Copy(window, w_size, window, 0, w_size);
match_start -= w_size;
strstart -= w_size;
block_start -= w_size;
num2 = hash_size;
int num3 = num2;
do
{
int num4 = head[--num3] & 0xFFFF;
head[num3] = (short)((num4 >= w_size) ? (num4 - w_size) : 0);
}while (--num2 != 0);
num2 = w_size;
num3 = num2;
do
{
int num4 = prev[--num3] & 0xFFFF;
prev[num3] = (short)((num4 >= w_size) ? (num4 - w_size) : 0);
}while (--num2 != 0);
num += w_size;
}
if (_codec.AvailableBytesIn == 0)
{
break;
}
num2 = _codec.read_buf(window, strstart + lookahead, num);
lookahead += num2;
if (lookahead >= MIN_MATCH)
{
ins_h = (window[strstart] & 0xFF);
ins_h = (((ins_h << hash_shift) ^ (window[strstart + 1] & 0xFF)) & hash_mask);
}
}while (lookahead < MIN_LOOKAHEAD && _codec.AvailableBytesIn != 0);
}
