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Small improvements

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Emmanuel Marty 2023-01-30 13:21:43 +01:00 committed by GitHub
parent 398885a52d
commit 583e4db62e
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 17 additions and 13 deletions
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30
src/shrink_block_v2.c
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@ -193,7 +193,7 @@ static inline int lzsa_write_match_varlen_v2(unsigned char *pOutData, int nOutOf
*/
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 nDepth) {
const lzsa_arrival *arrival = pCompressor->arrival + ((i - nStartOffset) << ARRIVALS_PER_POSITION_SHIFT_V2);
const int *rle_len = (int*)pCompressor->intervals /* reuse */;
const int *rle_len = (const int*)pCompressor->intervals /* reuse */;
lzsa_match* visited = ((lzsa_match*)pCompressor->pos_data) - nStartOffset /* reuse */;
int j;
@ -443,11 +443,11 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
nMinLen = nMaxRepLenForPos;
pInWindowAtPos = pInWindowStart + nMinLen;
while ((pInWindowAtPos + 8) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 8))
while ((pInWindowAtPos + 8) < pInWindowMax && !memcmp(pInWindowAtPos, pInWindowAtPos - nRepOffset, 8))
pInWindowAtPos += 8;
while ((pInWindowAtPos + 4) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 4))
while ((pInWindowAtPos + 4) < pInWindowMax && !memcmp(pInWindowAtPos, pInWindowAtPos - nRepOffset, 4))
pInWindowAtPos += 4;
while (pInWindowAtPos < pInWindowMax && pInWindowAtPos[-nRepOffset] == pInWindowAtPos[0])
while (pInWindowAtPos < pInWindowMax && pInWindowAtPos[0] == pInWindowAtPos[-nRepOffset])
pInWindowAtPos++;
const int nCurRepLen = (const int)(pInWindowAtPos - pInWindowStart);
@ -470,8 +470,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
for (m = 0; m < NMATCHES_PER_INDEX_V2 && match[m].length; m++) {
int nMatchLen = match[m].length & 0x7fff;
const int nMatchOffset = match[m].offset;
int nNoRepmatchOffsetCost;
int nNoRepmatchScore;
int nNoRepmatchOffsetCost = 0, nNoRepmatchScore = 0;
int nStartingMatchLen, k;
if ((i + nMatchLen) > nEndOffset)
@ -690,7 +689,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
}
if (nMatchLen >= LCP_MAX && ((m + 1) >= NMATCHES_PER_INDEX_V2 || match[m + 1].length < LCP_MAX))
if (nMatchLen >= LCP_MAX && ((m + 1) >= NMATCHES_PER_INDEX_V2 || (match[m + 1].length & 0x7fff) < LCP_MAX))
break;
}
}
@ -779,11 +778,13 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
}
}
if (pBestMatch[nNextIndex].offset && pMatch->offset != pBestMatch[nNextIndex].offset && nRepMatchOffset != pBestMatch[nNextIndex].offset) {
if (pBestMatch[nNextIndex].offset && pMatch->offset != pBestMatch[nNextIndex].offset) {
/* Otherwise, try to gain a match forward as well */
if (i >= pBestMatch[nNextIndex].offset && (i + pMatch->length) <= nEndOffset) {
int nMaxLen = 0;
const unsigned char *pInWindowAtPos = pInWindow + i;
while ((nMaxLen + 8) < pMatch->length && !memcmp(pInWindowAtPos + nMaxLen - pBestMatch[nNextIndex].offset, pInWindowAtPos + nMaxLen, 8))
nMaxLen += 8;
while ((nMaxLen + 4) < pMatch->length && !memcmp(pInWindowAtPos + nMaxLen - pBestMatch[nNextIndex].offset, pInWindowAtPos + nMaxLen, 4))
nMaxLen += 4;
while (nMaxLen < pMatch->length && pInWindowAtPos[nMaxLen - pBestMatch[nNextIndex].offset] == pInWindowAtPos[nMaxLen])
@ -799,9 +800,12 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
nPartialSizeBefore = lzsa_get_match_varlen_size_v2(pMatch->length - MIN_MATCH_SIZE_V2);
nPartialSizeBefore += (pMatch->offset <= 32) ? 4 : ((pMatch->offset <= 512) ? 8 : ((pMatch->offset <= (8192 + 512)) ? 12 : 16));
nPartialSizeBefore += lzsa_get_literals_varlen_size_v2(nNextLiterals);
nPartialSizeBefore += (pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16));
nPartialSizeAfter = lzsa_get_match_varlen_size_v2(nMaxLen - MIN_MATCH_SIZE_V2);
nPartialSizeAfter += lzsa_get_literals_varlen_size_v2(nNextLiterals + (pMatch->length - nMaxLen)) + ((pMatch->length - nMaxLen) << 3);
if (nRepMatchOffset != pBestMatch[nNextIndex].offset)
nPartialSizeAfter += (pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16));
if (nPartialSizeAfter < nPartialSizeBefore) {
const int nMatchLen = pMatch->length;
@ -1236,7 +1240,7 @@ int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigne
/* Compress optimally without breaking ties in favor of less tokens */
memset(pCompressor->best_match, 0, BLOCK_SIZE * sizeof(lzsa_match));
lzsa_optimize_forward_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */, (nInDataSize < 65536) ? 1 : 0 /* insert forward reps */, nArrivalsPerPosition);
lzsa_optimize_forward_v2(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, 0 /* reduce */, (nInDataSize < 65536) ? 1 : 0 /* insert forward reps */, nArrivalsPerPosition);
if (nInDataSize < 65536) {
int* first_offset_for_byte = pCompressor->first_offset_for_byte;
@ -1452,20 +1456,20 @@ int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigne
}
/* Compress optimally and do break ties in favor of less tokens */
lzsa_optimize_forward_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */, 0 /* use forward reps */, 1 << ARRIVALS_PER_POSITION_SHIFT_V2);
lzsa_optimize_forward_v2(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, 1 /* reduce */, 0 /* use forward reps */, NARRIVALS_PER_POSITION_V2_MAX);
}
/* Try to reduce final command set, wherever possible */
nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset);
nPasses++;
} while (nDidReduce && nPasses < 20);
/* Write compressed block */
nResult = lzsa_write_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nResult = lzsa_write_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, pOutData, nMaxOutDataSize);
if (nResult < 0 && (pCompressor->flags & LZSA_FLAG_RAW_BLOCK)) {
nResult = lzsa_write_raw_uncompressed_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nResult = lzsa_write_raw_uncompressed_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, pOutData, nMaxOutDataSize);
}
return nResult;