6502/lzsa
1
0
Fork 0
mirror of https://github.com/emmanuel-marty/lzsa.git synced 2024-12-29 16:29:16 +00:00
Code Issues Projects Releases Wiki Activity

Compress LZSA2 a tiny bit faster

Browse Source
This commit is contained in:
Emmanuel Marty 2020-06-18 17:47:31 +02:00 committed by GitHub
parent 1d0427ecae
commit b88d3465e3
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 43 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
src/shrink_block_v2.c
View File

@ -187,55 +187,62 @@ static inline int lzsa_write_match_varlen_v2(unsigned char *pOutData, int nOutOf
* @param nDepth current insertion depth
*/
static void lzsa_insert_forward_match_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int i, const int nMatchOffset, const int nStartOffset, const int nEndOffset, const int nMatchesPerArrival, int nDepth) {
lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << MATCHES_PER_ARRIVAL_SHIFT);
lzsa_arrival *arrival = pCompressor->arrival + ((i - nStartOffset) << MATCHES_PER_ARRIVAL_SHIFT);
int j;
int nPrevRepPos = -1, nPrevRepLen = -1, nPrevPrevRepPos = -1, nPrevPrevRepLen = -1;
if (nDepth >= 10) return;
for (j = 0; j < nMatchesPerArrival && arrival[j].from_slot; j++) {
int nRepOffset = arrival[j].rep_offset;
for (j = 0; j < nMatchesPerArrival && arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].from_slot; j++) {
int nRepOffset = arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].rep_offset;
if (nMatchOffset != nRepOffset && nRepOffset && arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].rep_len >= MIN_MATCH_SIZE_V2) {
int nRepPos = arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].rep_pos;
int nRepLen = arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].rep_len;
if (nMatchOffset != nRepOffset && nRepOffset && arrival[j].rep_len >= MIN_MATCH_SIZE_V2) {
int nRepPos = arrival[j].rep_pos;
int nRepLen = arrival[j].rep_len;
if (nRepPos > nMatchOffset &&
(nRepPos - nMatchOffset + nRepLen) <= (nEndOffset - LAST_LITERALS) &&
!memcmp(pInWindow + nRepPos - nRepOffset, pInWindow + nRepPos - nMatchOffset, nRepLen)) {
int nCurRepLen = nRepLen;
pCompressor->match[((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2) + NMATCHES_PER_INDEX_V2 - 1].length == 0) {
int nMaxRepLen = nEndOffset - nRepPos;
if (nMaxRepLen > LCP_MAX)
nMaxRepLen = LCP_MAX;
while ((nCurRepLen + 8) < nMaxRepLen && !memcmp(pInWindow + nRepPos + nCurRepLen, pInWindow + nRepPos - nMatchOffset + nCurRepLen, 8))
nCurRepLen += 8;
while ((nCurRepLen + 4) < nMaxRepLen && !memcmp(pInWindow + nRepPos + nCurRepLen, pInWindow + nRepPos - nMatchOffset + nCurRepLen, 4))
nCurRepLen += 4;
while (nCurRepLen < nMaxRepLen && pInWindow[nRepPos + nCurRepLen] == pInWindow[nRepPos - nMatchOffset + nCurRepLen])
nCurRepLen++;
if ((nPrevRepPos != nRepPos || nPrevRepLen != nRepLen) && (nPrevPrevRepPos != nRepPos || nPrevPrevRepLen != nRepLen)) {
nPrevPrevRepPos = nPrevRepPos;
nPrevPrevRepLen = nPrevRepLen;
nPrevRepPos = nRepPos;
nPrevRepLen = nRepLen;
lzsa_match *fwd_match = pCompressor->match + ((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2);
int exists = 0;
int r;
if (!memcmp(pInWindow + nRepPos, pInWindow + nRepPos - nMatchOffset, nRepLen)) {
int nCurRepLen = nRepLen;
for (r = 0; r < NMATCHES_PER_INDEX_V2 && fwd_match[r].length >= MIN_MATCH_SIZE_V2; r++) {
if (fwd_match[r].offset == nMatchOffset) {
exists = 1;
int nMaxRepLen = nEndOffset - nRepPos;
if (nMaxRepLen > LCP_MAX)
nMaxRepLen = LCP_MAX;
while ((nCurRepLen + 8) < nMaxRepLen && !memcmp(pInWindow + nRepPos + nCurRepLen, pInWindow + nRepPos - nMatchOffset + nCurRepLen, 8))
nCurRepLen += 8;
while ((nCurRepLen + 4) < nMaxRepLen && !memcmp(pInWindow + nRepPos + nCurRepLen, pInWindow + nRepPos - nMatchOffset + nCurRepLen, 4))
nCurRepLen += 4;
while (nCurRepLen < nMaxRepLen && pInWindow[nRepPos + nCurRepLen] == pInWindow[nRepPos - nMatchOffset + nCurRepLen])
nCurRepLen++;
if (fwd_match[r].length < nCurRepLen) {
fwd_match[r].length = nCurRepLen;
lzsa_insert_forward_match_v2(pCompressor, pInWindow, nRepPos, nMatchOffset, nStartOffset, nEndOffset, nMatchesPerArrival, nDepth + 1);
lzsa_match* fwd_match = pCompressor->match + ((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2);
int r;
for (r = 0; r < NMATCHES_PER_INDEX_V2 && fwd_match[r].length >= MIN_MATCH_SIZE_V2; r++) {
if (fwd_match[r].offset == nMatchOffset) {
if (fwd_match[r].length < nCurRepLen)
fwd_match[r].length = nCurRepLen;
r = NMATCHES_PER_INDEX_V2;
break;
}
}
if (r < NMATCHES_PER_INDEX_V2) {
fwd_match[r].offset = nMatchOffset;
fwd_match[r].length = nCurRepLen;
if (nDepth < 9)
lzsa_insert_forward_match_v2(pCompressor, pInWindow, nRepPos, nMatchOffset, nStartOffset, nEndOffset, nMatchesPerArrival, nDepth + 1);
}
break;
}
}
if (!exists && r < NMATCHES_PER_INDEX_V2) {
fwd_match[r].offset = nMatchOffset;
fwd_match[r].length = nCurRepLen;
lzsa_insert_forward_match_v2(pCompressor, pInWindow, nRepPos, nMatchOffset, nStartOffset, nEndOffset, nMatchesPerArrival, nDepth + 1);
}
}
}
}