private void Scan(byte[] raw, int end)
{
// We scan the input backwards, and always insert onto the
// front of the chain. This ensures that chains will have lower
// offsets at the front of the chain, allowing us to prefer the
// earlier match rather than the later match.
//
int lastHash = 0;
int ptr = end - DeltaIndex.BLKSZ;
do
{
int key = DeltaIndex.HashBlock(raw, ptr);
int tIdx = key & tableMask;
int head = table[tIdx];
if (head != 0 && lastHash == key)
{
// Two consecutive blocks have the same content hash,
// prefer the earlier block because we want to use the
// longest sequence we can during encoding.
//
entries[head] = (((long)key) << 32) | ptr;
}
else
{
int eIdx = ++entryCnt;
entries[eIdx] = (((long)key) << 32) | ptr;
next[eIdx] = head;
table[tIdx] = eIdx;
}
lastHash = key;
ptr -= DeltaIndex.BLKSZ;
}while (0 <= ptr);
}
