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Compress LZSA1 another 25% faster; minor cleanup

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Emmanuel Marty 2022-10-19 10:39:40 +02:00 committed by GitHub
parent ed81dd69df
commit 185ea0cbf2
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4 changed files with 43 additions and 120 deletions
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97
src/shrink_block_v1.c
View File

@ -151,12 +151,11 @@ static inline int lzsa_write_match_varlen_v1(unsigned char *pOutData, int nOutOf
* Attempt to pick optimal matches using a forward arrivals parser, so as to produce the smallest possible output that decompresses to the same input
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
* @param nReduce non-zero to reduce the number of tokens when the path costs are equal, zero not to
*/
static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce) {
static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset, const int nReduce) {
lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << ARRIVALS_PER_POSITION_SHIFT_V1);
const int nMinMatchSize = pCompressor->min_match_size;
const int nFavorRatio = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 1 : 0;
@ -290,6 +289,7 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, lzsa_match *p
}
const lzsa_arrival *end_arrival = &arrival[i << ARRIVALS_PER_POSITION_SHIFT_V1];
lzsa_match *pBestMatch = pCompressor->best_match - nStartOffset;
while (end_arrival->from_slot > 0 && end_arrival->from_pos >= 0 && (end_arrival->from_pos + nStartOffset) < nEndOffset) {
pBestMatch[end_arrival->from_pos + nStartOffset].length = end_arrival->match_len;
@ -304,13 +304,13 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, lzsa_match *p
*
* @param pCompressor compression context
* @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
* @param pBestMatch optimal matches to emit
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
*
* @return non-zero if the number of tokens was reduced, 0 if it wasn't
*/
static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset) {
lzsa_match *pBestMatch = pCompressor->best_match - nStartOffset;
int i;
int nNumLiterals = 0;
int nDidReduce = 0;
@ -409,59 +409,10 @@ static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const un
return nDidReduce;
}
/**
* Get compressed data block size
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
*
* @return size of compressed data that will be written to output buffer
*/
static int lzsa_get_compressed_size_v1(lzsa_compressor *pCompressor, const lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nCompressedSize = 0;
for (i = nStartOffset; i < nEndOffset; ) {
const lzsa_match *pMatch = pBestMatch + i;
if (pMatch->length >= MIN_MATCH_SIZE_V1) {
const int nMatchOffset = pMatch->offset;
const int nMatchLen = pMatch->length;
const int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V1;
const int nTokenLongOffset = (nMatchOffset <= 256) ? 0x00 : 0x80;
const int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3) + (nTokenLongOffset ? 16 : 8) /* match offset */ + lzsa_get_match_varlen_size_v1(nEncodedMatchLen);
nCompressedSize += nCommandSize;
nNumLiterals = 0;
i += nMatchLen;
}
else {
nNumLiterals++;
i++;
}
}
{
const int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3);
nCompressedSize += nCommandSize;
}
if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
nCompressedSize += 8 * 4;
}
return nCompressedSize;
}
/**
* Emit block of compressed data
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
@ -470,7 +421,8 @@ static int lzsa_get_compressed_size_v1(lzsa_compressor *pCompressor, const lzsa_
*
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
*/
static int lzsa_write_block_v1(lzsa_compressor *pCompressor, const lzsa_match *pBestMatch, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
static int lzsa_write_block_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
const lzsa_match *pBestMatch = pCompressor->best_match - nStartOffset;
int i;
int nNumLiterals = 0;
int nInFirstLiteralOffset = 0;
@ -668,44 +620,27 @@ static int lzsa_write_raw_uncompressed_block_v1(lzsa_compressor *pCompressor, co
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
*/
int lzsa_optimize_and_write_block_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
int nResult, nBaseCompressedSize;
int nResult;
/* Compress optimally without breaking ties in favor of less tokens */
memset(pCompressor->best_match, 0, BLOCK_SIZE * sizeof(lzsa_match));
lzsa_optimize_forward_v1(pCompressor, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */);
if (nInDataSize < 65536) {
lzsa_optimize_forward_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */);
}
else {
lzsa_optimize_forward_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */);
}
int nDidReduce;
int nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
nBaseCompressedSize = lzsa_get_compressed_size_v1(pCompressor, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
lzsa_match *pBestMatch = pCompressor->best_match - nPreviousBlockSize;
if (nBaseCompressedSize > 0 && nInDataSize < 65536) {
int nReducedCompressedSize;
/* Compress optimally and do break ties in favor of less tokens */
memset(pCompressor->improved_match, 0, BLOCK_SIZE * sizeof(lzsa_match));
lzsa_optimize_forward_v1(pCompressor, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */);
nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pInWindow, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
nReducedCompressedSize = lzsa_get_compressed_size_v1(pCompressor, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (nReducedCompressedSize > 0 && nReducedCompressedSize <= nBaseCompressedSize) {
/* Pick the parse with the reduced number of tokens as it didn't negatively affect the size */
pBestMatch = pCompressor->improved_match - nPreviousBlockSize;
}
}
nResult = lzsa_write_block_v1(pCompressor, pBestMatch, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nResult = lzsa_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
if (nResult < 0 && (pCompressor->flags & LZSA_FLAG_RAW_BLOCK)) {
nResult = lzsa_write_raw_uncompressed_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
}

11
src/shrink_block_v2.c
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@ -288,8 +288,8 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << ARRIVALS_PER_POSITION_SHIFT_V2);
const int *rle_len = (const int*)pCompressor->intervals /* reuse */;
lzsa_match *visited = ((lzsa_match*)pCompressor->pos_data) - nStartOffset /* reuse */;
char *nRepSlotHandledMask = pCompressor->rep_slot_handled_mask;
char *nRepLenHandledMask = pCompressor->rep_len_handled_mask;
unsigned char *nRepSlotHandledMask = pCompressor->rep_slot_handled_mask;
unsigned char *nRepLenHandledMask = pCompressor->rep_len_handled_mask;
const int nModeSwitchPenalty = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 0 : MODESWITCH_PENALTY;
const int nMinMatchSize = pCompressor->min_match_size;
const int nDisableScore = nReduce ? 0 : (2 * BLOCK_SIZE);
@ -463,9 +463,9 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
nRepMatchArrivalIdxAndLen[nNumRepMatchArrivals] = -1;
if (!nReduce) {
memset(nRepSlotHandledMask, 0, nArrivalsPerPosition * ((LCP_MAX + 1) / 8) * sizeof(char));
memset(nRepSlotHandledMask, 0, nArrivalsPerPosition * ((LCP_MAX + 1) / 8) * sizeof(unsigned char));
}
memset(nRepLenHandledMask, 0, ((LCP_MAX + 1) / 8) * sizeof(char));
memset(nRepLenHandledMask, 0, ((LCP_MAX + 1) / 8) * sizeof(unsigned char));
for (m = 0; m < NMATCHES_PER_INDEX_V2 && match[m].length; m++) {
int nMatchLen = match[m].length & 0x7fff;
@ -763,7 +763,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
nNextIndex++;
}
if (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length >= MIN_MATCH_SIZE_V2) {
if (nNextIndex < nEndOffset) {
/* This command is a match, is followed by 'nNextLiterals' literals and then by another match */
if (nRepMatchOffset && pMatch->offset != nRepMatchOffset && (pBestMatch[nNextIndex].offset != pMatch->offset ||
@ -773,7 +773,6 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
* matching large regions of identical bytes for instance, where there are too many offsets to be considered by the parser, and when not compressing to favor the
* ratio (the forward arrivals parser already has this covered). */
if (i >= nRepMatchOffset &&
(i + pMatch->length) <= nEndOffset &&
!memcmp(pInWindow + i - nRepMatchOffset, pInWindow + i, pMatch->length)) {
pMatch->offset = nRepMatchOffset;
nDidReduce = 1;

50
src/shrink_context.c
View File

@ -61,7 +61,6 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->open_intervals = NULL;
pCompressor->match = NULL;
pCompressor->best_match = NULL;
pCompressor->improved_match = NULL;
pCompressor->arrival = NULL;
pCompressor->rep_slot_handled_mask = NULL;
pCompressor->rep_len_handled_mask = NULL;
@ -101,35 +100,31 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->best_match = (lzsa_match *)malloc(BLOCK_SIZE * sizeof(lzsa_match));
if (pCompressor->best_match) {
pCompressor->improved_match = (lzsa_match *)malloc(BLOCK_SIZE * sizeof(lzsa_match));
if (pCompressor->improved_match) {
if (pCompressor->format_version == 2)
pCompressor->match = (lzsa_match *)malloc(BLOCK_SIZE * NMATCHES_PER_INDEX_V2 * sizeof(lzsa_match));
else
pCompressor->match = (lzsa_match *)malloc(BLOCK_SIZE * NMATCHES_PER_INDEX_V1 * sizeof(lzsa_match));
if (pCompressor->match) {
if (pCompressor->format_version == 2) {
pCompressor->rep_slot_handled_mask = (char*)malloc(NARRIVALS_PER_POSITION_V2_BIG * ((LCP_MAX + 1) / 8) * sizeof(char));
if (pCompressor->rep_slot_handled_mask) {
pCompressor->rep_len_handled_mask = (char*)malloc(((LCP_MAX + 1) / 8) * sizeof(char));
if (pCompressor->rep_len_handled_mask) {
pCompressor->first_offset_for_byte = (int*)malloc(65536 * sizeof(int));
if (pCompressor->first_offset_for_byte) {
pCompressor->next_offset_for_pos = (int*)malloc(BLOCK_SIZE * sizeof(int));
if (pCompressor->next_offset_for_pos) {
pCompressor->offset_cache = (int*)malloc(2048 * sizeof(int));
if (pCompressor->offset_cache) {
return 0;
}
if (pCompressor->format_version == 2)
pCompressor->match = (lzsa_match*)malloc(BLOCK_SIZE * NMATCHES_PER_INDEX_V2 * sizeof(lzsa_match));
else
pCompressor->match = (lzsa_match*)malloc(BLOCK_SIZE * NMATCHES_PER_INDEX_V1 * sizeof(lzsa_match));
if (pCompressor->match) {
if (pCompressor->format_version == 2) {
pCompressor->rep_slot_handled_mask = (unsigned char*)malloc(NARRIVALS_PER_POSITION_V2_BIG * ((LCP_MAX + 1) / 8) * sizeof(unsigned char));
if (pCompressor->rep_slot_handled_mask) {
pCompressor->rep_len_handled_mask = (unsigned char*)malloc(((LCP_MAX + 1) / 8) * sizeof(unsigned char));
if (pCompressor->rep_len_handled_mask) {
pCompressor->first_offset_for_byte = (int*)malloc(65536 * sizeof(int));
if (pCompressor->first_offset_for_byte) {
pCompressor->next_offset_for_pos = (int*)malloc(BLOCK_SIZE * sizeof(int));
if (pCompressor->next_offset_for_pos) {
pCompressor->offset_cache = (int*)malloc(2048 * sizeof(int));
if (pCompressor->offset_cache) {
return 0;
}
}
}
}
}
else {
return 0;
}
}
else {
return 0;
}
}
}
@ -181,11 +176,6 @@ void lzsa_compressor_destroy(lzsa_compressor *pCompressor) {
pCompressor->match = NULL;
}
if (pCompressor->improved_match) {
free(pCompressor->improved_match);
pCompressor->improved_match = NULL;
}
if (pCompressor->arrival) {
free(pCompressor->arrival);
pCompressor->arrival = NULL;

5
src/shrink_context.h
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@ -124,10 +124,9 @@ typedef struct _lzsa_compressor {
unsigned int *open_intervals;
lzsa_match *match;
lzsa_match *best_match;
lzsa_match *improved_match;
lzsa_arrival *arrival;
char *rep_slot_handled_mask;
char *rep_len_handled_mask;
unsigned char *rep_slot_handled_mask;
unsigned char *rep_len_handled_mask;
int *first_offset_for_byte;
int *next_offset_for_pos;
int *offset_cache;