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authorJuan J. Martinez <jjm@usebox.net>2022-09-06 07:37:20 +0100
committerJuan J. Martinez <jjm@usebox.net>2022-09-06 07:37:20 +0100
commit30bf0f51335e87812ffeb54e9437f0b6a1514d67 (patch)
tree9c85a2de53b4da69fcfaa84488cc6c12ebd3e5d0 /tools/rasm/lzsa-master/src/shrink_block_v1.c
parentd8990284057e6401d0374f439df51879595d804d (diff)
downloadubox-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_v1.c')
-rw-r--r--tools/rasm/lzsa-master/src/shrink_block_v1.c710
1 files changed, 710 insertions, 0 deletions
diff --git a/tools/rasm/lzsa-master/src/shrink_block_v1.c b/tools/rasm/lzsa-master/src/shrink_block_v1.c
new file mode 100644
index 0000000..32c5c38
--- /dev/null
+++ b/tools/rasm/lzsa-master/src/shrink_block_v1.c
@@ -0,0 +1,710 @@
+/*
+ * shrink_block_v1.c - LZSA1 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_v1.h"
+#include "format.h"
+
+/**
+ * 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_v1(const int nLength) {
+ if (nLength < LITERALS_RUN_LEN_V1) {
+ return 0;
+ }
+ else {
+ if (nLength < 256)
+ return 8;
+ else {
+ if (nLength < 512)
+ return 16;
+ else
+ return 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 nLength literals length
+ */
+static inline int lzsa_write_literals_varlen_v1(unsigned char *pOutData, int nOutOffset, int nLength) {
+ if (nLength >= LITERALS_RUN_LEN_V1) {
+ if (nLength < 256)
+ pOutData[nOutOffset++] = nLength - LITERALS_RUN_LEN_V1;
+ else {
+ if (nLength < 512) {
+ pOutData[nOutOffset++] = 250;
+ pOutData[nOutOffset++] = nLength - 256;
+ }
+ else {
+ pOutData[nOutOffset++] = 249;
+ 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_V1)
+ *
+ * @return number of extra bits required
+ */
+static inline int lzsa_get_match_varlen_size_v1(const int nLength) {
+ if (nLength < MATCH_RUN_LEN_V1) {
+ return 0;
+ }
+ else {
+ if ((nLength + MIN_MATCH_SIZE_V1) < 256)
+ return 8;
+ else {
+ if ((nLength + MIN_MATCH_SIZE_V1) < 512)
+ return 16;
+ else
+ return 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 nLength encoded match length (actual match length - MIN_MATCH_SIZE_V1)
+ */
+static inline int lzsa_write_match_varlen_v1(unsigned char *pOutData, int nOutOffset, int nLength) {
+ if (nLength >= MATCH_RUN_LEN_V1) {
+ if ((nLength + MIN_MATCH_SIZE_V1) < 256)
+ pOutData[nOutOffset++] = nLength - MATCH_RUN_LEN_V1;
+ else {
+ if ((nLength + MIN_MATCH_SIZE_V1) < 512) {
+ pOutData[nOutOffset++] = 239;
+ pOutData[nOutOffset++] = nLength + MIN_MATCH_SIZE_V1 - 256;
+ }
+ else {
+ pOutData[nOutOffset++] = 238;
+ pOutData[nOutOffset++] = (nLength + MIN_MATCH_SIZE_V1) & 0xff;
+ pOutData[nOutOffset++] = ((nLength + MIN_MATCH_SIZE_V1) >> 8) & 0xff;
+ }
+ }
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Get offset encoding cost in bits
+ *
+ * @param nMatchOffset offset to get cost of
+ *
+ * @return cost in bits
+ */
+static inline int lzsa_get_offset_cost_v1(const unsigned int nMatchOffset) {
+ return (nMatchOffset <= 256) ? 8 : 16;
+}
+
+/**
+ * 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 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
+ */
+static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce) {
+ lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << ARRIVALS_PER_POSITION_SHIFT);
+ const int nMinMatchSize = pCompressor->min_match_size;
+ const int nFavorRatio = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 1 : 0;
+ const int nModeSwitchPenalty = nFavorRatio ? 0 : MODESWITCH_PENALTY;
+ const int nDisableScore = nReduce ? 0 : (2 * BLOCK_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));
+
+ arrival[nStartOffset << ARRIVALS_PER_POSITION_SHIFT].from_slot = -1;
+
+ for (i = nStartOffset; i != nEndOffset; i++) {
+ lzsa_arrival* cur_arrival = &arrival[i << ARRIVALS_PER_POSITION_SHIFT];
+ int m;
+
+ for (j = 0; j < NARRIVALS_PER_POSITION_V1 && cur_arrival[j].from_slot; j++) {
+ int nPrevCost = cur_arrival[j].cost;
+ int nCodingChoiceCost = nPrevCost + 8 /* literal */;
+ int nScore = cur_arrival[j].score + 1;
+ int nNumLiterals = cur_arrival[j].num_literals + 1;
+
+ if (nNumLiterals == LITERALS_RUN_LEN_V1 || nNumLiterals == 256 || nNumLiterals == 512) {
+ nCodingChoiceCost += 8;
+ }
+
+ if (nNumLiterals == 1)
+ nCodingChoiceCost += nModeSwitchPenalty;
+
+ lzsa_arrival *pDestSlots = &arrival[(i + 1) << ARRIVALS_PER_POSITION_SHIFT];
+ for (n = 0; n < NARRIVALS_PER_POSITION_V1 /* we only need the literals + short match cost + long match cost cases */; n++) {
+ lzsa_arrival *pDestArrival = &pDestSlots[n];
+
+ if (pDestArrival->from_slot == 0 ||
+ nCodingChoiceCost < pDestArrival->cost ||
+ (nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
+ memmove(&arrival[((i + 1) << ARRIVALS_PER_POSITION_SHIFT) + n + 1],
+ &arrival[((i + 1) << ARRIVALS_PER_POSITION_SHIFT) + n],
+ sizeof(lzsa_arrival) * (NARRIVALS_PER_POSITION_V1 - n - 1));
+
+ 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 = cur_arrival[j].rep_offset;
+ break;
+ }
+ }
+ }
+
+ const lzsa_match *match = pCompressor->match + ((i - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V1);
+ int nNumArrivalsForThisPos = j;
+
+ for (m = 0; m < NMATCHES_PER_INDEX_V1 && match[m].length; m++) {
+ int nMatchLen = match[m].length;
+ int nMatchOffsetCost = lzsa_get_offset_cost_v1(match[m].offset);
+ int nStartingMatchLen, k;
+
+ if ((i + nMatchLen) > nEndOffset)
+ nMatchLen = nEndOffset - i;
+
+ if (nMatchLen >= LEAVE_ALONE_MATCH_SIZE)
+ nStartingMatchLen = nMatchLen;
+ else
+ nStartingMatchLen = nMinMatchSize;
+ for (k = nStartingMatchLen; k <= nMatchLen; k++) {
+ int nMatchLenCost = lzsa_get_match_varlen_size_v1(k - MIN_MATCH_SIZE_V1);
+
+ lzsa_arrival *pDestSlots = &arrival[(i + k) << ARRIVALS_PER_POSITION_SHIFT];
+
+ for (j = 0; j < nNumArrivalsForThisPos; j++) {
+ int nPrevCost = cur_arrival[j].cost;
+ int nCodingChoiceCost = nPrevCost + 8 /* token */ /* the actual cost of the literals themselves accumulates up the chain */ + nMatchOffsetCost + nMatchLenCost;
+ int exists = 0;
+
+ if (!cur_arrival[j].num_literals)
+ nCodingChoiceCost += nModeSwitchPenalty;
+
+ for (n = 0;
+ n < NARRIVALS_PER_POSITION_V1 && pDestSlots[n].from_slot && pDestSlots[n].cost <= nCodingChoiceCost;
+ n++) {
+ if (lzsa_get_offset_cost_v1(pDestSlots[n].rep_offset) == nMatchOffsetCost) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int nScore = cur_arrival[j].score + 5;
+
+ for (n = 0; n < NARRIVALS_PER_POSITION_V1 /* we only need the literals + short match cost + long match cost cases */; n++) {
+ lzsa_arrival *pDestArrival = &pDestSlots[n];
+
+ if (pDestArrival->from_slot == 0 ||
+ nCodingChoiceCost < pDestArrival->cost ||
+ (nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(lzsa_arrival) * (NARRIVALS_PER_POSITION_V1 - n - 1));
+
+ pDestArrival->cost = nCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->match_len = k;
+ pDestArrival->num_literals = 0;
+ pDestArrival->score = nScore;
+ pDestArrival->rep_offset = match[m].offset;
+ j = NARRIVALS_PER_POSITION_V1;
+ 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 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) {
+ int i;
+ int nNumLiterals = 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_V1 &&
+ 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_v1(pBestMatch[i + 1].length - MIN_MATCH_SIZE_V1);
+ int nReducedLenSize = lzsa_get_match_varlen_size_v1(pBestMatch[i + 1].length + 1 - MIN_MATCH_SIZE_V1);
+
+ 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_V1) {
+ if (pMatch->length <= 9 /* Don't waste time considering large matches, they will always win over literals */ &&
+ (i + pMatch->length) < nEndOffset /* Don't consider the last token 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_V1) {
+ nNextLiterals++;
+ nNextIndex++;
+ }
+
+ /* This command is a match, is followed by 'nNextLiterals' literals and then by another match, or the end of the input. Calculate this command's current cost (excluding 'nNumLiterals' bytes) */
+ if ((8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + ((pMatch->offset <= 256) ? 8 : 16) /* match offset */ + lzsa_get_match_varlen_size_v1(pMatch->length - MIN_MATCH_SIZE_V1) +
+ 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNextLiterals)) >=
+ (8 /* token */ + (pMatch->length << 3) + lzsa_get_literals_varlen_size_v1(nNumLiterals + pMatch->length + nNextLiterals))) {
+ /* Reduce */
+ int nMatchLen = pMatch->length;
+ int j;
+
+ for (j = 0; j < nMatchLen; j++) {
+ pBestMatch[i + j].length = 0;
+ }
+
+ nDidReduce = 1;
+ continue;
+ }
+ }
+
+ if ((i + pMatch->length) <= nEndOffset && pMatch->offset > 0 && pMatch->length >= MIN_MATCH_SIZE_V1 &&
+ pBestMatch[i + pMatch->length].offset > 0 &&
+ pBestMatch[i + pMatch->length].length >= MIN_MATCH_SIZE_V1 &&
+ (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 nCurPartialSize = lzsa_get_match_varlen_size_v1(pMatch->length - MIN_MATCH_SIZE_V1);
+ nCurPartialSize += 8 /* token */ + lzsa_get_literals_varlen_size_v1(0) + ((pBestMatch[i + pMatch->length].offset <= 256) ? 8 : 16) /* match offset */ + lzsa_get_match_varlen_size_v1(pBestMatch[i + pMatch->length].length - MIN_MATCH_SIZE_V1);
+
+ int nReducedPartialSize = lzsa_get_match_varlen_size_v1(pMatch->length + pBestMatch[i + pMatch->length].length - MIN_MATCH_SIZE_V1);
+
+ if (nCurPartialSize >= nReducedPartialSize) {
+ int nMatchLen = pMatch->length;
+
+ /* Join */
+
+ pMatch->length += pBestMatch[i + nMatchLen].length;
+ pBestMatch[i + nMatchLen].offset = 0;
+ pBestMatch[i + nMatchLen].length = -1;
+ continue;
+ }
+ }
+
+ 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_v1(lzsa_compressor *pCompressor, 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) {
+ int nMatchOffset = pMatch->offset;
+ int nMatchLen = pMatch->length;
+ int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V1;
+ int nTokenLongOffset = (nMatchOffset <= 256) ? 0x00 : 0x80;
+ 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++;
+ }
+ }
+
+ {
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(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_v1(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;
+
+ for (i = nStartOffset; i < nEndOffset; ) {
+ const lzsa_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length >= MIN_MATCH_SIZE_V1) {
+ int nMatchOffset = pMatch->offset;
+ int nMatchLen = pMatch->length;
+ int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V1;
+ int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
+ int nTokenMatchLen = (nEncodedMatchLen >= MATCH_RUN_LEN_V1) ? MATCH_RUN_LEN_V1 : nEncodedMatchLen;
+ int nTokenLongOffset = (nMatchOffset <= 256) ? 0x00 : 0x80;
+ 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);
+
+ if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
+ return -1;
+ if (nMatchOffset < MIN_OFFSET || nMatchOffset > MAX_OFFSET)
+ return -1;
+
+ pOutData[nOutOffset++] = nTokenLongOffset | (nTokenLiteralsLen << 4) | nTokenMatchLen;
+ nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
+
+ 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;
+ }
+
+ pOutData[nOutOffset++] = (-nMatchOffset) & 0xff;
+ if (nTokenLongOffset) {
+ pOutData[nOutOffset++] = (-nMatchOffset) >> 8;
+ }
+ nOutOffset = lzsa_write_match_varlen_v1(pOutData, nOutOffset, nEncodedMatchLen);
+
+ 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_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3);
+
+ if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
+ return -1;
+
+ if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK)
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x0f;
+ else
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x00;
+ nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
+
+ 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 + 4) > nMaxOutDataSize)
+ return -1;
+
+ pOutData[nOutOffset++] = 0;
+ pOutData[nOutOffset++] = 238;
+ pOutData[nOutOffset++] = 0;
+ pOutData[nOutOffset++] = 0;
+ }
+
+ 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_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
+ int nNumLiterals = nEndOffset - nStartOffset;
+ int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
+ int nOutOffset = 0;
+
+ int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3) + 4;
+ if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
+ return -1;
+
+ pCompressor->num_commands = 0;
+ pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x0f;
+
+ nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
+
+ if (nNumLiterals != 0) {
+ memcpy(pOutData + nOutOffset, pInWindow + nStartOffset, nNumLiterals);
+ nOutOffset += nNumLiterals;
+ nNumLiterals = 0;
+ }
+
+ pCompressor->num_commands++;
+
+ /* Emit EOD marker for raw block */
+
+ pOutData[nOutOffset++] = 0;
+ pOutData[nOutOffset++] = 238;
+ pOutData[nOutOffset++] = 0;
+ pOutData[nOutOffset++] = 0;
+
+ return nOutOffset;
+}
+
+/**
+ * Select the most optimal matches, reduce the token count if possible, and then emit a block of compressed LZSA1 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_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
+ int nResult, nBaseCompressedSize;
+
+ /* 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 */);
+
+ int nDidReduce;
+ int nPasses = 0;
+ do {
+ nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, 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);
+ if (nResult < 0 && pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
+ nResult = lzsa_write_raw_uncompressed_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
+ }
+
+ return nResult;
+}