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| author | Juan J. Martinez <jjm@usebox.net> | 2022-09-06 07:37:20 +0100 |
|---|---|---|
| committer | Juan J. Martinez <jjm@usebox.net> | 2022-09-06 07:37:20 +0100 |
| commit | 30bf0f51335e87812ffeb54e9437f0b6a1514d67 (patch) | |
| tree | 9c85a2de53b4da69fcfaa84488cc6c12ebd3e5d0 /tools/rasm/lzsa-master/src/shrink_block_v2.c | |
| parent | d8990284057e6401d0374f439df51879595d804d (diff) | |
| download | ubox-msx-lib-30bf0f51335e87812ffeb54e9437f0b6a1514d67.tar.gz ubox-msx-lib-30bf0f51335e87812ffeb54e9437f0b6a1514d67.zip | |
Updated rasm to 1.7
Diffstat (limited to 'tools/rasm/lzsa-master/src/shrink_block_v2.c')
| -rw-r--r-- | tools/rasm/lzsa-master/src/shrink_block_v2.c | 1371 |
1 files changed, 1371 insertions, 0 deletions
diff --git a/tools/rasm/lzsa-master/src/shrink_block_v2.c b/tools/rasm/lzsa-master/src/shrink_block_v2.c new file mode 100644 index 0000000..0aba0c0 --- /dev/null +++ b/tools/rasm/lzsa-master/src/shrink_block_v2.c @@ -0,0 +1,1371 @@ +/*
+ * shrink_block_v2.c - LZSA2 block compressor implementation
+ *
+ * Copyright (C) 2019 Emmanuel Marty
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ */
+
+/*
+ * Uses the libdivsufsort library Copyright (c) 2003-2008 Yuta Mori
+ *
+ * Inspired by LZ4 by Yann Collet. https://github.com/lz4/lz4
+ * With help, ideas, optimizations and speed measurements by spke <zxintrospec@gmail.com>
+ * With ideas from Lizard by Przemyslaw Skibinski and Yann Collet. https://github.com/inikep/lizard
+ * Also with ideas from smallz4 by Stephan Brumme. https://create.stephan-brumme.com/smallz4/
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "lib.h"
+#include "shrink_block_v2.h"
+#include "format.h"
+
+/**
+ * Write 4-bit nibble to output (compressed) buffer
+ *
+ * @param pOutData pointer to output buffer
+ * @param nOutOffset current write index into output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ * @param nCurNibbleOffset write index into output buffer, of current byte being filled with nibbles
+ * @param nNibbleValue value to write (0..15)
+ */
+static int lzsa_write_nibble_v2(unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, int *nCurNibbleOffset, int nNibbleValue) {
+ if (nOutOffset < 0) return -1;
+
+ if ((*nCurNibbleOffset) == -1) {
+ if (nOutOffset >= nMaxOutDataSize) return -1;
+ (*nCurNibbleOffset) = nOutOffset;
+ pOutData[nOutOffset++] = nNibbleValue << 4;
+ }
+ else {
+ pOutData[*nCurNibbleOffset] = (pOutData[*nCurNibbleOffset]) | (nNibbleValue & 0x0f);
+ (*nCurNibbleOffset) = -1;
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Get the number of extra bits required to represent a literals length
+ *
+ * @param nLength literals length
+ *
+ * @return number of extra bits required
+ */
+static inline int lzsa_get_literals_varlen_size_v2(const int nLength) {
+ if (nLength < LITERALS_RUN_LEN_V2) {
+ return 0;
+ }
+ else {
+ if (nLength < (LITERALS_RUN_LEN_V2 + 15)) {
+ return 4;
+ }
+ else {
+ if (nLength < 256)
+ return 4+8;
+ else {
+ return 4+24;
+ }
+ }
+ }
+}
+
+/**
+ * Write extra literals length bytes to output (compressed) buffer. The caller must first check that there is enough
+ * room to write the bytes.
+ *
+ * @param pOutData pointer to output buffer
+ * @param nOutOffset current write index into output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ * @param nCurNibbleOffset write index into output buffer, of current byte being filled with nibbles
+ * @param nLength literals length
+ */
+static inline int lzsa_write_literals_varlen_v2(unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, int *nCurNibbleOffset, int nLength) {
+ if (nLength >= LITERALS_RUN_LEN_V2) {
+ if (nLength < (LITERALS_RUN_LEN_V2 + 15)) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, nCurNibbleOffset, nLength - LITERALS_RUN_LEN_V2);
+ }
+ else {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, nCurNibbleOffset, 15);
+ if (nOutOffset < 0) return -1;
+
+ if (nLength < 256)
+ pOutData[nOutOffset++] = nLength - 18;
+ else {
+ pOutData[nOutOffset++] = 239;
+ pOutData[nOutOffset++] = nLength & 0xff;
+ pOutData[nOutOffset++] = (nLength >> 8) & 0xff;
+ }
+ }
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Get the number of extra bits required to represent an encoded match length
+ *
+ * @param nLength encoded match length (actual match length - MIN_MATCH_SIZE_V2)
+ *
+ * @return number of extra bits required
+ */
+static inline int lzsa_get_match_varlen_size_v2(const int nLength) {
+ if (nLength < MATCH_RUN_LEN_V2) {
+ return 0;
+ }
+ else {
+ if (nLength < (MATCH_RUN_LEN_V2 + 15))
+ return 4;
+ else {
+ if ((nLength + MIN_MATCH_SIZE_V2) < 256)
+ return 4+8;
+ else {
+ return 4 + 24;
+ }
+ }
+ }
+}
+
+/**
+ * Write extra encoded match length bytes to output (compressed) buffer. The caller must first check that there is enough
+ * room to write the bytes.
+ *
+ * @param pOutData pointer to output buffer
+ * @param nOutOffset current write index into output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ * @param nCurNibbleOffset write index into output buffer, of current byte being filled with nibbles
+ * @param nLength encoded match length (actual match length - MIN_MATCH_SIZE_V2)
+ */
+static inline int lzsa_write_match_varlen_v2(unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, int *nCurNibbleOffset, int nLength) {
+ if (nLength >= MATCH_RUN_LEN_V2) {
+ if (nLength < (MATCH_RUN_LEN_V2 + 15)) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, nCurNibbleOffset, nLength - MATCH_RUN_LEN_V2);
+ }
+ else {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, nCurNibbleOffset, 15);
+ if (nOutOffset < 0) return -1;
+
+ if ((nLength + MIN_MATCH_SIZE_V2) < 256)
+ pOutData[nOutOffset++] = nLength + MIN_MATCH_SIZE_V2 - 24;
+ else {
+ pOutData[nOutOffset++] = 233;
+ pOutData[nOutOffset++] = (nLength + MIN_MATCH_SIZE_V2) & 0xff;
+ pOutData[nOutOffset++] = ((nLength + MIN_MATCH_SIZE_V2) >> 8) & 0xff;
+ }
+ }
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Insert forward rep candidate
+ *
+ * @param pCompressor compression context
+ * @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
+ * @param i input data window position whose matches are being considered
+ * @param nMatchOffset match offset to use as rep candidate
+ * @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 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, int nDepth) {
+ lzsa_arrival *arrival = pCompressor->arrival + ((i - nStartOffset) << ARRIVALS_PER_POSITION_SHIFT);
+ const int *rle_end = (int*)pCompressor->intervals /* reuse */;
+ lzsa_match* visited = ((lzsa_match*)pCompressor->pos_data) - nStartOffset /* reuse */;
+ int j;
+
+ for (j = 0; j < NARRIVALS_PER_POSITION_V2_BIG && arrival[j].from_slot; j++) {
+ int nRepOffset = arrival[j].rep_offset;
+
+ 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 + nRepLen) <= nEndOffset &&
+ pCompressor->match[((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2) + NMATCHES_PER_INDEX_V2 - 1].length == 0) {
+
+ if (visited[nRepPos].offset != nMatchOffset || visited[nRepPos].length > nRepLen) {
+ visited[nRepPos].offset = nMatchOffset;
+ visited[nRepPos].length = nRepLen;
+
+ if (pInWindow[nRepPos] == pInWindow[nRepPos - nMatchOffset]) {
+ int nLen0 = rle_end[nRepPos - nMatchOffset] - (nRepPos - nMatchOffset);
+ int nLen1 = rle_end[nRepPos] - (nRepPos);
+ int nMinLen = (nLen0 < nLen1) ? nLen0 : nLen1;
+
+ if (nMinLen >= nRepLen || !memcmp(pInWindow + nRepPos + nMinLen, pInWindow + nRepPos + nMinLen - nMatchOffset, nRepLen - nMinLen)) {
+ visited[nRepPos].length = 0;
+
+ 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) {
+ r = NMATCHES_PER_INDEX_V2;
+ break;
+ }
+ }
+
+ if (r < NMATCHES_PER_INDEX_V2) {
+ int nMaxRepLen = nEndOffset - nRepPos;
+ if (nMaxRepLen > LCP_MAX)
+ nMaxRepLen = LCP_MAX;
+ int nCurRepLen = (nMinLen > nRepLen) ? nMinLen : nRepLen;
+ if (nCurRepLen > nMaxRepLen)
+ nCurRepLen = nMaxRepLen;
+ const unsigned char* pInWindowMax = pInWindow + nRepPos + nMaxRepLen;
+ const unsigned char* pInWindowAtRepPos = pInWindow + nRepPos + nCurRepLen;
+ while ((pInWindowAtRepPos + 8) < pInWindowMax && !memcmp(pInWindowAtRepPos, pInWindowAtRepPos - nMatchOffset, 8))
+ pInWindowAtRepPos += 8;
+ while ((pInWindowAtRepPos + 4) < pInWindowMax && !memcmp(pInWindowAtRepPos, pInWindowAtRepPos - nMatchOffset, 4))
+ pInWindowAtRepPos += 4;
+ while (pInWindowAtRepPos < pInWindowMax && pInWindowAtRepPos[0] == pInWindowAtRepPos[-nMatchOffset])
+ pInWindowAtRepPos++;
+
+ nCurRepLen = (int)(pInWindowAtRepPos - (pInWindow + nRepPos));
+ fwd_match[r].offset = nMatchOffset;
+ fwd_match[r].length = nCurRepLen;
+
+ if (nDepth < 9)
+ lzsa_insert_forward_match_v2(pCompressor, pInWindow, nRepPos, nMatchOffset, nStartOffset, nEndOffset, nDepth + 1);
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+/**
+ * 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 pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
+ * @param pBestMatch pointer to buffer for outputting optimal matches
+ * @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
+ * @param nInsertForwardReps non-zero to insert forward repmatch candidates, zero to use the previously inserted candidates
+ * @param nArrivalsPerPosition number of arrivals to record per input buffer position
+ */
+static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce, const int nInsertForwardReps, const int nArrivalsPerPosition) {
+ lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << ARRIVALS_PER_POSITION_SHIFT);
+ const int *rle_end = (int*)pCompressor->intervals /* reuse */;
+ lzsa_match *visited = ((lzsa_match*)pCompressor->pos_data) - nStartOffset /* reuse */;
+ char *nRepLenHandledMask = pCompressor->rep_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);
+ const int nMaxRepInsertedLen = nReduce ? LEAVE_ALONE_MATCH_SIZE : 0;
+ const int nLeaveAloneMatchSize = (nArrivalsPerPosition == NARRIVALS_PER_POSITION_V2_SMALL) ? LEAVE_ALONE_MATCH_SIZE_SMALL : LEAVE_ALONE_MATCH_SIZE;
+ int i, j, n;
+
+ if ((nEndOffset - nStartOffset) > BLOCK_SIZE) return;
+
+ memset(arrival + (nStartOffset << ARRIVALS_PER_POSITION_SHIFT), 0, sizeof(lzsa_arrival) * ((nEndOffset - nStartOffset + 1) << ARRIVALS_PER_POSITION_SHIFT));
+
+ for (i = (nStartOffset << ARRIVALS_PER_POSITION_SHIFT); i != ((nEndOffset + 1) << ARRIVALS_PER_POSITION_SHIFT); i++) {
+ arrival[i].cost = 0x40000000;
+ }
+
+ arrival[nStartOffset << ARRIVALS_PER_POSITION_SHIFT].from_slot = -1;
+
+ if (nInsertForwardReps) {
+ memset(visited + nStartOffset, 0, (nEndOffset - nStartOffset) * sizeof(lzsa_match));
+ }
+
+ for (i = nStartOffset; i != nEndOffset; i++) {
+ lzsa_arrival *cur_arrival = &arrival[i << ARRIVALS_PER_POSITION_SHIFT];
+ int m;
+
+ for (j = 0; j < nArrivalsPerPosition && cur_arrival[j].from_slot; j++) {
+ const int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nCodingChoiceCost = nPrevCost + 8 /* literal */;
+ int nNumLiterals = cur_arrival[j].num_literals + 1;
+
+ if (nNumLiterals == LITERALS_RUN_LEN_V2) {
+ nCodingChoiceCost += 4;
+ }
+ else if (nNumLiterals == (LITERALS_RUN_LEN_V2 + 15)) {
+ nCodingChoiceCost += 8;
+ }
+ else if (nNumLiterals == 256) {
+ nCodingChoiceCost += 16;
+ }
+
+ if (nNumLiterals == 1)
+ nCodingChoiceCost += nModeSwitchPenalty;
+
+ lzsa_arrival *pDestSlots = &cur_arrival[1 << ARRIVALS_PER_POSITION_SHIFT];
+ if (nCodingChoiceCost <= pDestSlots[nArrivalsPerPosition - 1].cost) {
+ int nRepOffset = cur_arrival[j].rep_offset;
+ int exists = 0;
+
+ for (n = 0;
+ n < nArrivalsPerPosition && pDestSlots[n].cost < nCodingChoiceCost;
+ n++) {
+ if (pDestSlots[n].rep_offset == nRepOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int nScore = cur_arrival[j].score + 1;
+
+ for (;
+ n < nArrivalsPerPosition && pDestSlots[n].cost == nCodingChoiceCost && nScore >= (pDestSlots[n].score + nDisableScore);
+ n++) {
+ if (pDestSlots[n].rep_offset == nRepOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ if (n < nArrivalsPerPosition) {
+ int nn;
+
+ for (nn = n;
+ nn < nArrivalsPerPosition && pDestSlots[nn].cost == nCodingChoiceCost;
+ nn++) {
+ if (pDestSlots[nn].rep_offset == nRepOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int z;
+
+ for (z = n; z < nArrivalsPerPosition - 1 && pDestSlots[z].from_slot; z++) {
+ if (pDestSlots[z].rep_offset == nRepOffset)
+ break;
+ }
+
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(lzsa_arrival) * (z - n));
+
+ lzsa_arrival* pDestArrival = &pDestSlots[n];
+ pDestArrival->cost = nCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->match_len = 0;
+ pDestArrival->num_literals = nNumLiterals;
+ pDestArrival->score = nScore;
+ pDestArrival->rep_offset = nRepOffset;
+ pDestArrival->rep_pos = cur_arrival[j].rep_pos;
+ pDestArrival->rep_len = cur_arrival[j].rep_len;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ lzsa_match *match = pCompressor->match + ((i - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2);
+ int nNumArrivalsForThisPos = j, nMinOverallRepLen = 0, nMaxOverallRepLen = 0;
+
+ int nRepLenForArrival[NARRIVALS_PER_POSITION_V2_BIG];
+ memset(nRepLenForArrival, 0, nArrivalsPerPosition * sizeof(int));
+
+ int nMaxRepLenForPos = nEndOffset - i;
+ if (nMaxRepLenForPos > LCP_MAX)
+ nMaxRepLenForPos = LCP_MAX;
+ const unsigned char* pInWindowStart = pInWindow + i;
+ const unsigned char* pInWindowMax = pInWindowStart + nMaxRepLenForPos;
+
+ for (j = 0; j < nNumArrivalsForThisPos && (i + MIN_MATCH_SIZE_V2) <= nEndOffset; j++) {
+ int nRepOffset = cur_arrival[j].rep_offset;
+
+ if (nRepOffset) {
+ if (i > nRepOffset) {
+ if (pInWindow[i] == pInWindow[i - nRepOffset]) {
+ const unsigned char* pInWindowAtPos;
+
+ int nLen0 = rle_end[i - nRepOffset] - (i - nRepOffset);
+ int nLen1 = rle_end[i] - (i);
+ int nMinLen = (nLen0 < nLen1) ? nLen0 : nLen1;
+
+ if (nMinLen > nMaxRepLenForPos)
+ nMinLen = nMaxRepLenForPos;
+ pInWindowAtPos = pInWindowStart + nMinLen;
+
+ while ((pInWindowAtPos + 8) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 8))
+ pInWindowAtPos += 8;
+ while ((pInWindowAtPos + 4) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 4))
+ pInWindowAtPos += 4;
+ while (pInWindowAtPos < pInWindowMax && pInWindowAtPos[-nRepOffset] == pInWindowAtPos[0])
+ pInWindowAtPos++;
+ nRepLenForArrival[j] = (int)(pInWindowAtPos - pInWindowStart);
+
+ if (nMaxOverallRepLen < nRepLenForArrival[j])
+ nMaxOverallRepLen = nRepLenForArrival[j];
+ }
+ }
+ }
+ }
+
+ if (!nReduce) {
+ memset(nRepLenHandledMask, 0, nArrivalsPerPosition * ((LCP_MAX + 1) / 8) * sizeof(char));
+ }
+
+ for (m = 0; m < NMATCHES_PER_INDEX_V2 && match[m].length; m++) {
+ int nMatchLen = match[m].length & 0x7fff;
+ int nMatchOffset = match[m].offset;
+ int nScorePenalty = 3 + ((match[m].length & 0x8000) >> 15);
+ int nNoRepmatchOffsetCost = (nMatchOffset <= 32) ? 4 : ((nMatchOffset <= 512) ? 8 : ((nMatchOffset <= (8192 + 512)) ? 12 : 16));
+ int nStartingMatchLen, k;
+
+ if ((i + nMatchLen) > nEndOffset)
+ nMatchLen = nEndOffset - i;
+
+ if (nInsertForwardReps)
+ lzsa_insert_forward_match_v2(pCompressor, pInWindow, i, nMatchOffset, nStartOffset, nEndOffset, 0);
+
+ int nNonRepMatchArrivalIdx = -1;
+ for (j = 0; j < nNumArrivalsForThisPos; j++) {
+ int nRepOffset = cur_arrival[j].rep_offset;
+
+ if (nMatchOffset != nRepOffset) {
+ nNonRepMatchArrivalIdx = j;
+ break;
+ }
+ }
+
+ int nMatchLenCost;
+ if (nMatchLen >= nLeaveAloneMatchSize) {
+ nStartingMatchLen = nMatchLen;
+ nMatchLenCost = 4 + 24 + 8 /* token */;
+ }
+ else {
+ nStartingMatchLen = nMinMatchSize;
+ nMatchLenCost = 0 + 8 /* token */;
+ }
+
+ for (k = nStartingMatchLen; k <= nMatchLen; k++) {
+ if (k == (MATCH_RUN_LEN_V2 + MIN_MATCH_SIZE_V2)) {
+ nMatchLenCost = 4 + 8 /* token */;
+ }
+ else {
+ if (k == (MATCH_RUN_LEN_V2 + 15 + MIN_MATCH_SIZE_V2))
+ nMatchLenCost = 4 + 8 + 8 /* token */;
+ else {
+ if (k == 256)
+ nMatchLenCost = 4 + 24 + 8 /* token */;
+ }
+ }
+
+ lzsa_arrival *pDestSlots = &cur_arrival[k << ARRIVALS_PER_POSITION_SHIFT];
+
+ /* Insert non-repmatch candidate */
+
+ if (nNonRepMatchArrivalIdx >= 0) {
+ const int nPrevCost = cur_arrival[nNonRepMatchArrivalIdx].cost & 0x3fffffff;
+ int nCodingChoiceCost = nPrevCost /* the actual cost of the literals themselves accumulates up the chain */ + nMatchLenCost + nNoRepmatchOffsetCost;
+
+ if (!cur_arrival[nNonRepMatchArrivalIdx].num_literals)
+ nCodingChoiceCost += nModeSwitchPenalty;
+
+ int nScore = cur_arrival[nNonRepMatchArrivalIdx].score + nScorePenalty;
+ if (nCodingChoiceCost < pDestSlots[nArrivalsPerPosition - 2].cost ||
+ (nCodingChoiceCost == pDestSlots[nArrivalsPerPosition - 2].cost && nScore < (pDestSlots[nArrivalsPerPosition - 2].score + nDisableScore))) {
+ int exists = 0;
+
+ for (n = 0;
+ n < nArrivalsPerPosition && pDestSlots[n].cost < nCodingChoiceCost;
+ n++) {
+ if (pDestSlots[n].rep_offset == nMatchOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ for (;
+ n < nArrivalsPerPosition && pDestSlots[n].cost == nCodingChoiceCost && nScore >= (pDestSlots[n].score + nDisableScore);
+ n++) {
+ if (pDestSlots[n].rep_offset == nMatchOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ if (n < nArrivalsPerPosition - 1) {
+ int nn;
+
+ for (nn = n;
+ nn < nArrivalsPerPosition && pDestSlots[nn].cost == nCodingChoiceCost;
+ nn++) {
+ if (pDestSlots[nn].rep_offset == nMatchOffset &&
+ (!nInsertForwardReps || pDestSlots[nn].rep_pos >= i ||
+ pDestSlots[nArrivalsPerPosition - 1].from_slot)) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int z;
+
+ for (z = n; z < nArrivalsPerPosition - 1 && pDestSlots[z].from_slot; z++) {
+ if (pDestSlots[z].rep_offset == nMatchOffset)
+ break;
+ }
+
+ if (z == (nArrivalsPerPosition - 1) && pDestSlots[z].from_slot && pDestSlots[z].match_len < MIN_MATCH_SIZE_V2)
+ z--;
+
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(lzsa_arrival) * (z - n));
+
+ lzsa_arrival* pDestArrival = &pDestSlots[n];
+ pDestArrival->cost = nCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = nNonRepMatchArrivalIdx + 1;
+ pDestArrival->match_len = k;
+ pDestArrival->num_literals = 0;
+ pDestArrival->score = nScore;
+ pDestArrival->rep_offset = nMatchOffset;
+ pDestArrival->rep_pos = i;
+ pDestArrival->rep_len = k;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /* Insert repmatch candidates */
+
+ if (k > nMinOverallRepLen && k <= nMaxOverallRepLen) {
+ for (j = 0; j < nNumArrivalsForThisPos; j++) {
+ int nMaskOffset = (j << 7) + (k >> 3);
+ if (nRepLenForArrival[j] >= k && (nReduce || !(nRepLenHandledMask[nMaskOffset] & (1 << (k & 7))))) {
+ const int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nRepCodingChoiceCost = nPrevCost /* the actual cost of the literals themselves accumulates up the chain */ + nMatchLenCost;
+ int nScore = cur_arrival[j].score + 2;
+
+ if (nRepCodingChoiceCost < pDestSlots[nArrivalsPerPosition - 1].cost ||
+ (nRepCodingChoiceCost == pDestSlots[nArrivalsPerPosition - 1].cost && nScore < (pDestSlots[nArrivalsPerPosition - 1].score + nDisableScore))) {
+ int nRepOffset = cur_arrival[j].rep_offset;
+ int exists = 0;
+
+ for (n = 0;
+ n < nArrivalsPerPosition && pDestSlots[n].cost < nRepCodingChoiceCost;
+ n++) {
+ if (pDestSlots[n].rep_offset == nRepOffset) {
+ exists = 1;
+ if (!nReduce)
+ nRepLenHandledMask[nMaskOffset] |= 1 << (k & 7);
+ break;
+ }
+ }
+
+ if (!exists) {
+ for (;
+ n < nArrivalsPerPosition && pDestSlots[n].cost == nRepCodingChoiceCost && nScore >= (pDestSlots[n].score + nDisableScore);
+ n++) {
+ if (pDestSlots[n].rep_offset == nRepOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ if (n < nArrivalsPerPosition) {
+ int nn;
+
+ for (nn = n;
+ nn < nArrivalsPerPosition && pDestSlots[nn].cost == nRepCodingChoiceCost;
+ nn++) {
+ if (pDestSlots[nn].rep_offset == nRepOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int z;
+
+ for (z = n; z < nArrivalsPerPosition - 1 && pDestSlots[z].from_slot; z++) {
+ if (pDestSlots[z].rep_offset == nRepOffset)
+ break;
+ }
+
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(lzsa_arrival) * (z - n));
+
+ lzsa_arrival* pDestArrival = &pDestSlots[n];
+ pDestArrival->cost = nRepCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->match_len = k;
+ pDestArrival->num_literals = 0;
+ pDestArrival->score = nScore;
+ pDestArrival->rep_offset = nRepOffset;
+ pDestArrival->rep_pos = i;
+ pDestArrival->rep_len = k;
+ }
+ }
+ }
+ }
+ }
+ else {
+ break;
+ }
+ }
+ }
+
+ if (k < nMaxRepInsertedLen)
+ nMinOverallRepLen = k;
+ }
+ }
+
+ if (nMatchLen >= LCP_MAX && ((m + 1) >= NMATCHES_PER_INDEX_V2 || match[m + 1].length < LCP_MAX))
+ break;
+ }
+ }
+
+ lzsa_arrival *end_arrival = &arrival[(i << ARRIVALS_PER_POSITION_SHIFT) + 0];
+
+ while (end_arrival->from_slot > 0 && end_arrival->from_pos >= 0) {
+ if (end_arrival->from_pos >= nEndOffset) return;
+ pBestMatch[end_arrival->from_pos].length = end_arrival->match_len;
+ if (end_arrival->match_len)
+ pBestMatch[end_arrival->from_pos].offset = end_arrival->rep_offset;
+ else
+ pBestMatch[end_arrival->from_pos].offset = 0;
+ end_arrival = &arrival[(end_arrival->from_pos << ARRIVALS_PER_POSITION_SHIFT) + (end_arrival->from_slot - 1)];
+ }
+}
+
+/**
+ * Attempt to minimize the number of commands issued in the compressed data block, in order to speed up decompression without
+ * impacting the compression ratio
+ *
+ * @param pCompressor compression context
+ * @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
+ * @param pBestMatch optimal matches to evaluate and update
+ * @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_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
+ int i;
+ int nNumLiterals = 0;
+ int nPrevRepMatchOffset = 0;
+ int nRepMatchOffset = 0;
+ int nRepMatchLen = 0;
+ int nRepIndex = 0;
+ int nDidReduce = 0;
+
+ for (i = nStartOffset; i < nEndOffset; ) {
+ lzsa_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length == 0 &&
+ (i + 1) < nEndOffset &&
+ pBestMatch[i + 1].length >= MIN_MATCH_SIZE_V2 &&
+ pBestMatch[i + 1].length < MAX_VARLEN &&
+ pBestMatch[i + 1].offset &&
+ i >= pBestMatch[i + 1].offset &&
+ (i + pBestMatch[i + 1].length + 1) <= nEndOffset &&
+ !memcmp(pInWindow + i - (pBestMatch[i + 1].offset), pInWindow + i, pBestMatch[i + 1].length + 1)) {
+ int nCurLenSize = lzsa_get_match_varlen_size_v2(pBestMatch[i + 1].length - MIN_MATCH_SIZE_V2);
+ int nReducedLenSize = lzsa_get_match_varlen_size_v2(pBestMatch[i + 1].length + 1 - MIN_MATCH_SIZE_V2);
+
+ if ((nReducedLenSize - nCurLenSize) <= 8) {
+ /* Merge */
+ pBestMatch[i].length = pBestMatch[i + 1].length + 1;
+ pBestMatch[i].offset = pBestMatch[i + 1].offset;
+ pBestMatch[i + 1].length = 0;
+ pBestMatch[i + 1].offset = 0;
+ nDidReduce = 1;
+ continue;
+ }
+ }
+
+ if (pMatch->length >= MIN_MATCH_SIZE_V2) {
+ if ((i + pMatch->length) < nEndOffset /* Don't consider the last match in the block, we can only reduce a match inbetween other tokens */) {
+ int nNextIndex = i + pMatch->length;
+ int nNextLiterals = 0;
+
+ while (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length < MIN_MATCH_SIZE_V2) {
+ nNextLiterals++;
+ nNextIndex++;
+ }
+
+ if (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length >= MIN_MATCH_SIZE_V2) {
+ /* 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 || pBestMatch[nNextIndex].offset == nRepMatchOffset ||
+ ((pMatch->offset <= 32) ? 4 : ((pMatch->offset <= 512) ? 8 : ((pMatch->offset <= (8192 + 512)) ? 12 : 16))) >
+ ((pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16))))) {
+ /* Check if we can change the current match's offset to be the same as the previous match's offset, and get an extra repmatch. This will occur when
+ * 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 - nRepMatchOffset + pMatch->length) <= nEndOffset &&
+ !memcmp(pInWindow + i - nRepMatchOffset, pInWindow + i - pMatch->offset, pMatch->length)) {
+ pMatch->offset = nRepMatchOffset;
+ nDidReduce = 1;
+ }
+ }
+
+ if (pBestMatch[nNextIndex].offset && pMatch->offset != pBestMatch[nNextIndex].offset && nRepMatchOffset != pBestMatch[nNextIndex].offset) {
+ /* Otherwise, try to gain a match forward as well */
+ if (i > pBestMatch[nNextIndex].offset && (i - pBestMatch[nNextIndex].offset + pMatch->length) <= nEndOffset) {
+ int nMaxLen = 0;
+ while (nMaxLen < pMatch->length && pInWindow[i - pBestMatch[nNextIndex].offset + nMaxLen] == pInWindow[i - pMatch->offset + nMaxLen])
+ nMaxLen++;
+ if (nMaxLen >= pMatch->length) {
+ /* Replace */
+ pMatch->offset = pBestMatch[nNextIndex].offset;
+ nDidReduce = 1;
+ }
+ else if (nMaxLen >= 2 && pMatch->offset != nRepMatchOffset) {
+ int nPartialSizeBefore, nPartialSizeAfter;
+
+ 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);
+
+ 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 (nPartialSizeAfter < nPartialSizeBefore) {
+ int j;
+
+ /* We gain a repmatch that is shorter than the original match as this is the best we can do, so it is followed by extra literals, but
+ * we have calculated that this is shorter */
+ pMatch->offset = pBestMatch[nNextIndex].offset;
+ for (j = nMaxLen; j < pMatch->length; j++) {
+ pBestMatch[i + j].length = 0;
+ }
+ pMatch->length = nMaxLen;
+ nDidReduce = 1;
+ }
+ }
+ }
+ }
+
+ if (pMatch->length < 9 /* Don't waste time considering large matches, they will always win over literals */) {
+ /* Calculate this command's current cost (excluding 'nNumLiterals' bytes) */
+
+ int nCurCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + lzsa_get_match_varlen_size_v2(pMatch->length - MIN_MATCH_SIZE_V2);
+ if (pMatch->offset != nRepMatchOffset)
+ nCurCommandSize += (pMatch->offset <= 32) ? 4 : ((pMatch->offset <= 512) ? 8 : ((pMatch->offset <= (8192 + 512)) ? 12 : 16));
+
+ /* Calculate the next command's current cost */
+ int nNextCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNextLiterals) + /* (nNextLiterals << 3) + */ lzsa_get_match_varlen_size_v2(pBestMatch[nNextIndex].length - MIN_MATCH_SIZE_V2);
+ if (pBestMatch[nNextIndex].offset != pMatch->offset)
+ nNextCommandSize += (pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16));
+
+ int nOriginalCombinedCommandSize = nCurCommandSize + nNextCommandSize;
+
+ /* Calculate the cost of replacing this match command by literals + the next command with the cost of encoding these literals (excluding 'nNumLiterals' bytes) */
+ int nReducedCommandSize = (pMatch->length << 3) + 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals + pMatch->length + nNextLiterals) + /* (nNextLiterals << 3) + */ lzsa_get_match_varlen_size_v2(pBestMatch[nNextIndex].length - MIN_MATCH_SIZE_V2);
+ if (pBestMatch[nNextIndex].offset != nRepMatchOffset)
+ nReducedCommandSize += (pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16));
+
+ int nReplaceRepOffset = 0;
+ if (nRepMatchOffset && nRepMatchOffset != nPrevRepMatchOffset && nRepMatchLen >= MIN_MATCH_SIZE_V2 && nRepMatchOffset != pBestMatch[nNextIndex].offset && nRepIndex > pBestMatch[nNextIndex].offset &&
+ (nRepIndex - pBestMatch[nNextIndex].offset + nRepMatchLen) <= nEndOffset &&
+ !memcmp(pInWindow + nRepIndex - nRepMatchOffset, pInWindow + nRepIndex - pBestMatch[nNextIndex].offset, nRepMatchLen)) {
+ /* Replacing this match command by literals would let us create a repmatch */
+ nReplaceRepOffset = 1;
+ nReducedCommandSize -= (nRepMatchOffset <= 32) ? 4 : ((nRepMatchOffset <= 512) ? 8 : ((nRepMatchOffset <= (8192 + 512)) ? 12 : 16));
+ }
+
+ if (nOriginalCombinedCommandSize >= nReducedCommandSize) {
+ /* Reduce */
+ int nMatchLen = pMatch->length;
+ int j;
+
+ for (j = 0; j < nMatchLen; j++) {
+ pBestMatch[i + j].length = 0;
+ }
+
+ nDidReduce = 1;
+
+ if (nReplaceRepOffset) {
+ pBestMatch[nRepIndex].offset = pBestMatch[nNextIndex].offset;
+ nRepMatchOffset = pBestMatch[nNextIndex].offset;
+ }
+ continue;
+ }
+ }
+ }
+ }
+
+ if ((i + pMatch->length) <= nEndOffset && pMatch->offset > 0 && pMatch->length >= MIN_MATCH_SIZE_V2 &&
+ pBestMatch[i + pMatch->length].offset > 0 &&
+ pBestMatch[i + pMatch->length].length >= MIN_MATCH_SIZE_V2 &&
+ (pMatch->length + pBestMatch[i + pMatch->length].length) >= LEAVE_ALONE_MATCH_SIZE &&
+ (pMatch->length + pBestMatch[i + pMatch->length].length) <= MAX_VARLEN &&
+ (i + pMatch->length) > pMatch->offset &&
+ (i + pMatch->length) > pBestMatch[i + pMatch->length].offset &&
+ (i + pMatch->length + pBestMatch[i + pMatch->length].length) <= nEndOffset &&
+ !memcmp(pInWindow + i - pMatch->offset + pMatch->length,
+ pInWindow + i + pMatch->length - pBestMatch[i + pMatch->length].offset,
+ pBestMatch[i + pMatch->length].length)) {
+
+ int nNextIndex = i + pMatch->length;
+
+ while (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length < MIN_MATCH_SIZE_V2) {
+ nNextIndex++;
+ }
+
+ int nNextOffset;
+ if (nNextIndex < nEndOffset)
+ nNextOffset = pBestMatch[nNextIndex].offset;
+ else
+ nNextOffset = 0;
+
+ int nCurPartialSize = lzsa_get_match_varlen_size_v2(pMatch->length - MIN_MATCH_SIZE_V2);
+
+ nCurPartialSize += 8 /* token */ + /* lzsa_get_literals_varlen_size_v2(0) + */ lzsa_get_match_varlen_size_v2(pBestMatch[i + pMatch->length].length - MIN_MATCH_SIZE_V2);
+ if (pBestMatch[i + pMatch->length].offset != pMatch->offset)
+ nCurPartialSize += (pBestMatch[i + pMatch->length].offset <= 32) ? 4 : ((pBestMatch[i + pMatch->length].offset <= 512) ? 8 : ((pBestMatch[i + pMatch->length].offset <= (8192 + 512)) ? 12 : 16));
+
+ if (nNextOffset != pBestMatch[i + pMatch->length].offset)
+ nCurPartialSize += (nNextOffset <= 32) ? 4 : ((nNextOffset <= 512) ? 8 : ((nNextOffset <= (8192 + 512)) ? 12 : 16));
+
+ int nReducedPartialSize = lzsa_get_match_varlen_size_v2(pMatch->length + pBestMatch[i + pMatch->length].length - MIN_MATCH_SIZE_V2);
+
+ if (nNextOffset != pMatch->offset)
+ nReducedPartialSize += (nNextOffset <= 32) ? 4 : ((nNextOffset <= 512) ? 8 : ((nNextOffset <= (8192 + 512)) ? 12 : 16));
+
+ if (nCurPartialSize >= nReducedPartialSize) {
+ int nMatchLen = pMatch->length;
+
+ /* Join */
+
+ pMatch->length += pBestMatch[i + nMatchLen].length;
+ pBestMatch[i + nMatchLen].offset = 0;
+ pBestMatch[i + nMatchLen].length = -1;
+ nDidReduce = 1;
+ continue;
+ }
+ }
+
+ nPrevRepMatchOffset = nRepMatchOffset;
+ nRepMatchOffset = pMatch->offset;
+ nRepMatchLen = pMatch->length;
+ nRepIndex = i;
+
+ i += pMatch->length;
+ nNumLiterals = 0;
+ }
+ else {
+ nNumLiterals++;
+ i++;
+ }
+ }
+
+ 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_v2(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
+ int i;
+ int nNumLiterals = 0;
+ int nRepMatchOffset = 0;
+ int nCompressedSize = 0;
+
+ for (i = nStartOffset; i < nEndOffset; ) {
+ const lzsa_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length >= MIN_MATCH_SIZE_V2) {
+ int nMatchOffset = pMatch->offset;
+ int nMatchLen = pMatch->length;
+ int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V2;
+ int nOffsetSize;
+
+ if (nMatchOffset == nRepMatchOffset) {
+ nOffsetSize = 0;
+ }
+ else {
+ if (nMatchOffset <= 32) {
+ nOffsetSize = 4;
+ }
+ else if (nMatchOffset <= 512) {
+ nOffsetSize = 8;
+ }
+ else if (nMatchOffset <= (8192 + 512)) {
+ nOffsetSize = 12;
+ }
+ else {
+ nOffsetSize = 16;
+ }
+ }
+
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3) + nOffsetSize /* match offset */ + lzsa_get_match_varlen_size_v2(nEncodedMatchLen);
+ nCompressedSize += nCommandSize;
+
+ nNumLiterals = 0;
+ nRepMatchOffset = nMatchOffset;
+ i += nMatchLen;
+ }
+ else {
+ nNumLiterals++;
+ i++;
+ }
+ }
+
+ {
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3);
+
+ nCompressedSize += nCommandSize;
+ nNumLiterals = 0;
+ }
+
+ 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
+ * @param pOutData pointer to output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+static int lzsa_write_block_v2(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
+ int i;
+ int nNumLiterals = 0;
+ int nInFirstLiteralOffset = 0;
+ int nOutOffset = 0;
+ int nCurNibbleOffset = -1;
+ int nRepMatchOffset = 0;
+
+ for (i = nStartOffset; i < nEndOffset; ) {
+ const lzsa_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length >= MIN_MATCH_SIZE_V2) {
+ int nMatchOffset = pMatch->offset;
+ int nMatchLen = pMatch->length;
+ int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V2;
+ int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V2) ? LITERALS_RUN_LEN_V2 : nNumLiterals;
+ int nTokenMatchLen = (nEncodedMatchLen >= MATCH_RUN_LEN_V2) ? MATCH_RUN_LEN_V2 : nEncodedMatchLen;
+ int nTokenOffsetMode;
+ int nOffsetSize;
+
+ if (nMatchOffset == nRepMatchOffset) {
+ nTokenOffsetMode = 0xe0;
+ nOffsetSize = 0;
+ }
+ else {
+ if (nMatchOffset <= 32) {
+ nTokenOffsetMode = 0x00 | ((((-nMatchOffset) & 0x01) << 5) ^ 0x20);
+ nOffsetSize = 4;
+ }
+ else if (nMatchOffset <= 512) {
+ nTokenOffsetMode = 0x40 | ((((-nMatchOffset) & 0x100) >> 3) ^ 0x20);
+ nOffsetSize = 8;
+ }
+ else if (nMatchOffset <= (8192 + 512)) {
+ nTokenOffsetMode = 0x80 | ((((-(nMatchOffset - 512)) & 0x0100) >> 3) ^ 0x20);
+ nOffsetSize = 12;
+ }
+ else {
+ nTokenOffsetMode = 0xc0;
+ nOffsetSize = 16;
+ }
+ }
+
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3) + nOffsetSize /* match offset */ + lzsa_get_match_varlen_size_v2(nEncodedMatchLen);
+
+ if ((nOutOffset + ((nCommandSize + 7) >> 3)) > nMaxOutDataSize)
+ return -1;
+ if (nMatchOffset < MIN_OFFSET || nMatchOffset > MAX_OFFSET)
+ return -1;
+
+ pOutData[nOutOffset++] = nTokenOffsetMode | (nTokenLiteralsLen << 3) | nTokenMatchLen;
+ nOutOffset = lzsa_write_literals_varlen_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, nNumLiterals);
+ if (nOutOffset < 0) return -1;
+
+ if (nNumLiterals < pCompressor->stats.min_literals || pCompressor->stats.min_literals == -1)
+ pCompressor->stats.min_literals = nNumLiterals;
+ if (nNumLiterals > pCompressor->stats.max_literals)
+ pCompressor->stats.max_literals = nNumLiterals;
+ pCompressor->stats.total_literals += nNumLiterals;
+ pCompressor->stats.literals_divisor++;
+
+ if (nNumLiterals != 0) {
+ memcpy(pOutData + nOutOffset, pInWindow + nInFirstLiteralOffset, nNumLiterals);
+ nOutOffset += nNumLiterals;
+ nNumLiterals = 0;
+ }
+
+ if (nTokenOffsetMode == 0x00 || nTokenOffsetMode == 0x20) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, ((-nMatchOffset) & 0x1e) >> 1);
+ if (nOutOffset < 0) return -1;
+ }
+ else if (nTokenOffsetMode == 0x40 || nTokenOffsetMode == 0x60) {
+ pOutData[nOutOffset++] = (-nMatchOffset) & 0xff;
+ }
+ else if (nTokenOffsetMode == 0x80 || nTokenOffsetMode == 0xa0) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, ((-(nMatchOffset - 512)) >> 9) & 0x0f);
+ if (nOutOffset < 0) return -1;
+ pOutData[nOutOffset++] = (-(nMatchOffset - 512)) & 0xff;
+ }
+ else if (nTokenOffsetMode == 0xc0) {
+ pOutData[nOutOffset++] = (-nMatchOffset) >> 8;
+ pOutData[nOutOffset++] = (-nMatchOffset) & 0xff;
+ }
+
+ if (nMatchOffset == nRepMatchOffset)
+ pCompressor->stats.num_rep_offsets++;
+
+ nRepMatchOffset = nMatchOffset;
+
+ nOutOffset = lzsa_write_match_varlen_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, nEncodedMatchLen);
+ if (nOutOffset < 0) return -1;
+
+ if (nMatchOffset < pCompressor->stats.min_offset || pCompressor->stats.min_offset == -1)
+ pCompressor->stats.min_offset = nMatchOffset;
+ if (nMatchOffset > pCompressor->stats.max_offset)
+ pCompressor->stats.max_offset = nMatchOffset;
+ pCompressor->stats.total_offsets += nMatchOffset;
+
+ if (nMatchLen < pCompressor->stats.min_match_len || pCompressor->stats.min_match_len == -1)
+ pCompressor->stats.min_match_len = nMatchLen;
+ if (nMatchLen > pCompressor->stats.max_match_len)
+ pCompressor->stats.max_match_len = nMatchLen;
+ pCompressor->stats.total_match_lens += nMatchLen;
+ pCompressor->stats.match_divisor++;
+
+ if (nMatchOffset == 1) {
+ if (nMatchLen < pCompressor->stats.min_rle1_len || pCompressor->stats.min_rle1_len == -1)
+ pCompressor->stats.min_rle1_len = nMatchLen;
+ if (nMatchLen > pCompressor->stats.max_rle1_len)
+ pCompressor->stats.max_rle1_len = nMatchLen;
+ pCompressor->stats.total_rle1_lens += nMatchLen;
+ pCompressor->stats.rle1_divisor++;
+ }
+ else if (nMatchOffset == 2) {
+ if (nMatchLen < pCompressor->stats.min_rle2_len || pCompressor->stats.min_rle2_len == -1)
+ pCompressor->stats.min_rle2_len = nMatchLen;
+ if (nMatchLen > pCompressor->stats.max_rle2_len)
+ pCompressor->stats.max_rle2_len = nMatchLen;
+ pCompressor->stats.total_rle2_lens += nMatchLen;
+ pCompressor->stats.rle2_divisor++;
+ }
+
+ i += nMatchLen;
+
+ if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
+ int nCurSafeDist = (i - nStartOffset) - nOutOffset;
+ if (nCurSafeDist >= 0 && pCompressor->safe_dist < nCurSafeDist)
+ pCompressor->safe_dist = nCurSafeDist;
+ }
+
+ pCompressor->num_commands++;
+ }
+ else {
+ if (nNumLiterals == 0)
+ nInFirstLiteralOffset = i;
+ nNumLiterals++;
+ i++;
+ }
+ }
+
+ {
+ int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V2) ? LITERALS_RUN_LEN_V2 : nNumLiterals;
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3);
+
+ if ((nOutOffset + ((nCommandSize + 7) >> 3)) > nMaxOutDataSize)
+ return -1;
+
+ if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK)
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 3) | 0xe7;
+ else
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 3) | 0x00;
+ nOutOffset = lzsa_write_literals_varlen_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, nNumLiterals);
+ if (nOutOffset < 0) return -1;
+
+ if (nNumLiterals < pCompressor->stats.min_literals || pCompressor->stats.min_literals == -1)
+ pCompressor->stats.min_literals = nNumLiterals;
+ if (nNumLiterals > pCompressor->stats.max_literals)
+ pCompressor->stats.max_literals = nNumLiterals;
+ pCompressor->stats.total_literals += nNumLiterals;
+ pCompressor->stats.literals_divisor++;
+
+ if (nNumLiterals != 0) {
+ memcpy(pOutData + nOutOffset, pInWindow + nInFirstLiteralOffset, nNumLiterals);
+ nOutOffset += nNumLiterals;
+ nNumLiterals = 0;
+ }
+
+ if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
+ int nCurSafeDist = (i - nStartOffset) - nOutOffset;
+ if (nCurSafeDist >= 0 && pCompressor->safe_dist < nCurSafeDist)
+ pCompressor->safe_dist = nCurSafeDist;
+ }
+
+ pCompressor->num_commands++;
+ }
+
+ if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
+ /* Emit EOD marker for raw block */
+
+ if (nOutOffset >= nMaxOutDataSize)
+ return -1;
+
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, 15); /* Extended match length nibble */
+ if (nOutOffset < 0) return -1;
+
+ if ((nOutOffset + 1) > nMaxOutDataSize)
+ return -1;
+
+ pOutData[nOutOffset++] = 232; /* EOD match length byte */
+ }
+
+ if (nCurNibbleOffset != -1) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, 0);
+ if (nOutOffset < 0 || nCurNibbleOffset != -1)
+ return -1;
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Emit raw block of uncompressible data
+ *
+ * @param pCompressor compression context
+ * @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
+ * @param pOutData pointer to output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+static int lzsa_write_raw_uncompressed_block_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
+ int nCurNibbleOffset = -1;
+ int nNumLiterals = nEndOffset - nStartOffset;
+ int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V2) ? LITERALS_RUN_LEN_V2 : nNumLiterals;
+ int nOutOffset = 0;
+
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3) + 4 + 8;
+ if ((nOutOffset + ((nCommandSize + 7) >> 3)) > nMaxOutDataSize)
+ return -1;
+
+ pCompressor->num_commands = 0;
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 3) | 0xe7;
+
+ nOutOffset = lzsa_write_literals_varlen_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, nNumLiterals);
+ if (nOutOffset < 0) return -1;
+
+ if (nNumLiterals != 0) {
+ memcpy(pOutData + nOutOffset, pInWindow + nStartOffset, nNumLiterals);
+ nOutOffset += nNumLiterals;
+ nNumLiterals = 0;
+ }
+
+ /* Emit EOD marker for raw block */
+
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, 15); /* Extended match length nibble */
+ if (nOutOffset < 0) return -1;
+
+ if ((nOutOffset + 1) > nMaxOutDataSize)
+ return -1;
+
+ pOutData[nOutOffset++] = 232; /* EOD match length byte */
+
+ pCompressor->num_commands++;
+
+ if (nCurNibbleOffset != -1) {
+ nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, 0);
+ if (nOutOffset < 0 || nCurNibbleOffset != -1)
+ return -1;
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Select the most optimal matches, reduce the token count if possible, and then emit a block of compressed LZSA2 data
+ *
+ * @param pCompressor compression context
+ * @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
+ * @param nPreviousBlockSize number of previously compressed bytes (or 0 for none)
+ * @param nInDataSize number of input bytes to compress
+ * @param pOutData pointer to output buffer
+ * @param nMaxOutDataSize maximum size of output buffer, in bytes
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
+ int nResult, nBaseCompressedSize;
+ int nArrivalsPerPosition = (nInDataSize < 65536) ? NARRIVALS_PER_POSITION_V2_BIG : NARRIVALS_PER_POSITION_V2_SMALL;
+ int *rle_end = (int*)pCompressor->intervals /* reuse */;
+ int i;
+
+ i = 0;
+ while (i < (nPreviousBlockSize + nInDataSize)) {
+ int nRangeStartIdx = i;
+ unsigned char c = pInWindow[nRangeStartIdx];
+ do {
+ i++;
+ } while (i < (nPreviousBlockSize + nInDataSize) && pInWindow[i] == c);
+ while (nRangeStartIdx < i) {
+ rle_end[nRangeStartIdx++] = i;
+ }
+ }
+
+ /* 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, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */, (nInDataSize < 65536) ? 1 : 0 /* insert forward reps */, nArrivalsPerPosition);
+
+ int nDidReduce;
+ int nPasses = 0;
+ do {
+ nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
+ nPasses++;
+ } while (nDidReduce && nPasses < 20);
+
+ nBaseCompressedSize = lzsa_get_compressed_size_v2(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_v2(pCompressor, pInWindow, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */, 0 /* use forward reps */, nArrivalsPerPosition);
+
+ nPasses = 0;
+ do {
+ nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
+ nPasses++;
+ } while (nDidReduce && nPasses < 20);
+
+ nReducedCompressedSize = lzsa_get_compressed_size_v2(pCompressor, pCompressor->improved_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
+ if (nReducedCompressedSize > 0 && nReducedCompressedSize <= nBaseCompressedSize) {
+ const int nEndOffset = nPreviousBlockSize + nInDataSize;
+ int nSupplementedCompressedSize;
+
+ /* Pick the parse with the reduced number of tokens as it didn't negatively affect the size */
+ pBestMatch = pCompressor->improved_match - nPreviousBlockSize;
+
+ int* first_offset_for_byte = pCompressor->first_offset_for_byte;
+ int* next_offset_for_pos = pCompressor->next_offset_for_pos;
+ int nPosition;
+
+ /* Supplement small matches */
+
+ memset(first_offset_for_byte, 0xff, sizeof(int) * 65536);
+ memset(next_offset_for_pos, 0xff, sizeof(int) * nInDataSize);
+
+ for (nPosition = nPreviousBlockSize; nPosition < nEndOffset - 1; nPosition++) {
+ next_offset_for_pos[nPosition - nPreviousBlockSize] = first_offset_for_byte[((unsigned int)pInWindow[nPosition]) | (((unsigned int)pInWindow[nPosition + 1]) << 8)];
+ first_offset_for_byte[((unsigned int)pInWindow[nPosition]) | (((unsigned int)pInWindow[nPosition + 1]) << 8)] = nPosition;
+ }
+
+ for (nPosition = nPreviousBlockSize + 1; nPosition < (nEndOffset - 1); nPosition++) {
+ lzsa_match* match = pCompressor->match + ((nPosition - nPreviousBlockSize) << MATCHES_PER_INDEX_SHIFT_V2);
+ int m = 0, nInserted = 0;
+ int nMatchPos;
+
+ while (m < 15 && match[m].length)
+ m++;
+
+ for (nMatchPos = next_offset_for_pos[nPosition - nPreviousBlockSize]; m < 15 && nMatchPos >= 0; nMatchPos = next_offset_for_pos[nMatchPos - nPreviousBlockSize]) {
+ int nMatchOffset = nPosition - nMatchPos;
+ int nExistingMatchIdx;
+ int nAlreadyExists = 0;
+
+ for (nExistingMatchIdx = 0; nExistingMatchIdx < m; nExistingMatchIdx++) {
+ if (match[nExistingMatchIdx].offset == nMatchOffset) {
+ nAlreadyExists = 1;
+ break;
+ }
+ }
+
+ if (!nAlreadyExists) {
+ int nMatchLen = 2;
+ while (nMatchLen < 16 && (nPosition + nMatchLen + 4) < nEndOffset && !memcmp(pInWindow + nMatchPos + nMatchLen, pInWindow + nPosition + nMatchLen, 4))
+ nMatchLen += 4;
+ while (nMatchLen < 16 && (nPosition + nMatchLen) < nEndOffset && pInWindow[nMatchPos + nMatchLen] == pInWindow[nPosition + nMatchLen])
+ nMatchLen++;
+ match[m].length = nMatchLen;
+ match[m].offset = nMatchOffset;
+ m++;
+ nInserted++;
+ if (nInserted >= 15)
+ break;
+ }
+ }
+ }
+
+ /* Compress optimally with the extra matches */
+ memset(pCompressor->best_match, 0, BLOCK_SIZE * sizeof(lzsa_match));
+ lzsa_optimize_forward_v2(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */, 0 /* use forward reps */, nArrivalsPerPosition);
+
+ nPasses = 0;
+ do {
+ nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
+ nPasses++;
+ } while (nDidReduce && nPasses < 20);
+
+ nSupplementedCompressedSize = lzsa_get_compressed_size_v2(pCompressor, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
+ if (nSupplementedCompressedSize > 0 && nSupplementedCompressedSize < nReducedCompressedSize) {
+ /* Pick the parse with the extra matches as it didn't negatively affect the size */
+ pBestMatch = pCompressor->best_match - nPreviousBlockSize;
+ }
+ }
+ }
+
+ nResult = lzsa_write_block_v2(pCompressor, pBestMatch, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 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);
+ }
+
+ return nResult;
+}
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