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| author | Juan J. Martinez <jjm@usebox.net> | 2021-01-09 09:01:05 +0000 |
|---|---|---|
| committer | Juan J. Martinez <jjm@usebox.net> | 2021-01-09 09:01:05 +0000 |
| commit | 9bcf1e97960c0da7322a868efdbc07e2650716fe (patch) | |
| tree | de6d32ad5b0e567991bd3eb262902c15a77074d9 /tools/apultra/src/shrink.c | |
| parent | 3b31adf01305e522f7e28c1435fb47418ce43267 (diff) | |
| download | ubox-msx-lib-9bcf1e97960c0da7322a868efdbc07e2650716fe.tar.gz ubox-msx-lib-9bcf1e97960c0da7322a868efdbc07e2650716fe.zip | |
Extra libs: ap.lib
aPLib support with apultra.
Diffstat (limited to 'tools/apultra/src/shrink.c')
| -rw-r--r-- | tools/apultra/src/shrink.c | 1728 |
1 files changed, 1728 insertions, 0 deletions
diff --git a/tools/apultra/src/shrink.c b/tools/apultra/src/shrink.c new file mode 100644 index 0000000..c6c9826 --- /dev/null +++ b/tools/apultra/src/shrink.c @@ -0,0 +1,1728 @@ +/*
+ * shrink.c - 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 cap by Sven-Åke Dahl. https://github.com/svendahl/cap
+ * Also inspired by Charles Bloom's compression blog. http://cbloomrants.blogspot.com/
+ * With ideas from LZ4 by Yann Collet. https://github.com/lz4/lz4
+ * With help and support from spke <zxintrospec@gmail.com>
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include "libapultra.h"
+#include "matchfinder.h"
+#include "shrink.h"
+#include "format.h"
+
+#define TOKEN_CODE_LARGE_MATCH 2 /* 10 */
+#define TOKEN_SIZE_LARGE_MATCH 2
+
+#define TOKEN_CODE_7BIT_MATCH 6 /* 110 */
+#define TOKEN_SIZE_7BIT_MATCH 3
+
+#define TOKEN_CODE_4BIT_MATCH 7 /* 111 */
+#define TOKEN_SIZE_4BIT_MATCH 3
+
+#define CountShift(N,bits) if ((N)>>(bits)) { (N)>>=(bits); (n) += (bits); }
+
+/** Gamma2 bit counts for common values, up to 255 */
+static char _gamma2_size[256] = {
+ 0, 0, 2, 2, 4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+};
+
+/**
+ * Write bitpacked value 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 nValue value to write
+ * @param nBits number of least significant bits to write in value
+ * @param nCurBitsOffset write index into output buffer, of current byte being filled with bits
+ * @param nCurBitShift bit shift count
+ *
+ * @return updated write index into output buffer, or -1 in case of an error
+ */
+static int apultra_write_bits(unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, const int nValue, const int nBits, int *nCurBitsOffset, int *nCurBitShift) {
+ int i;
+
+ if (nOutOffset < 0) return -1;
+
+ for (i = nBits - 1; i >= 0; i--) {
+ if ((*nCurBitsOffset) == INT_MIN) {
+ /* Allocate a new byte in the stream to pack bits in */
+ if (nOutOffset >= nMaxOutDataSize) return -1;
+ (*nCurBitsOffset) = nOutOffset;
+ (*nCurBitShift) = 7;
+ pOutData[nOutOffset++] = 0;
+ }
+
+ pOutData[(*nCurBitsOffset)] |= ((nValue >> i) & 1) << (*nCurBitShift);
+
+ (*nCurBitShift) --;
+ if ((*nCurBitShift) == -1) {
+ /* Current byte is full */
+ (*nCurBitsOffset) = INT_MIN;
+ }
+ }
+
+ return nOutOffset;
+}
+
+/**
+ * Get size of gamma2 encoded value
+ *
+ * @param nValue value of evaluate (2..n)
+ *
+ * @return number of bits required
+ */
+static int apultra_get_gamma2_size(int nValue) {
+ if (nValue >= 0 && nValue < 256)
+ return _gamma2_size[nValue];
+ else {
+ unsigned int n = 0;
+ CountShift(nValue, 16);
+ CountShift(nValue, 8);
+ CountShift(nValue, 4);
+ CountShift(nValue, 2);
+ CountShift(nValue, 1);
+
+ return n << 1;
+ }
+}
+
+/**
+ * Write gamma2 encoded value 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 nValue value of write (2..n)
+ * @param nCurBitsOffset write index into output buffer, of current byte being filled with bits
+ * @param nCurBitShift bit shift count
+ *
+ * @return updated write index into output buffer, or -1 in case of an error
+ */
+static int apultra_write_gamma2_value(unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, int nValue, int *nCurBitsOffset, int *nCurBitShift) {
+ int msb = 30;
+ while ((nValue >> msb--) == 0);
+
+ while (msb > 0) {
+ int bit = (nValue >> msb) & 1;
+
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, bit, 1, nCurBitsOffset, nCurBitShift);
+ msb--;
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, 1, 1, nCurBitsOffset, nCurBitShift);
+ }
+
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, nValue & 1, 1, nCurBitsOffset, nCurBitShift);
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, 0, 1, nCurBitsOffset, nCurBitShift);
+ return nOutOffset;
+}
+
+/**
+ * Get the number of extra bits required to represent a match offset
+ *
+ * @param nLength match length
+ * @param nMatchOffset match offset
+ * @param nFollowsLiteral non-zero if the match follows a literal, zero if it immediately follows another match
+ *
+ * @return number of extra bits required
+ */
+static inline int apultra_get_offset_varlen_size(const int nLength, const int nMatchOffset, const int nFollowsLiteral) {
+ if (nLength <= 3 && nMatchOffset < 128)
+ return 8 + TOKEN_SIZE_7BIT_MATCH;
+ else {
+ if (nFollowsLiteral)
+ return 8 + TOKEN_SIZE_LARGE_MATCH + apultra_get_gamma2_size((nMatchOffset >> 8) + 3);
+ else
+ return 8 + TOKEN_SIZE_LARGE_MATCH + apultra_get_gamma2_size((nMatchOffset >> 8) + 2);
+ }
+}
+
+/**
+ * Get the number of extra bits required to represent a match length
+ *
+ * @param nLength match length
+ * @param nMatchOffset match offset
+ *
+ * @return number of extra bits required
+ */
+static inline int apultra_get_match_varlen_size(int nLength, const int nMatchOffset) {
+ if (nLength <= 3 && nMatchOffset < 128)
+ return 0;
+ else {
+ if (nMatchOffset < 128 || nMatchOffset >= MINMATCH4_OFFSET)
+ return apultra_get_gamma2_size(nLength - 2);
+ else if (nMatchOffset < MINMATCH3_OFFSET)
+ return apultra_get_gamma2_size(nLength);
+ else
+ return apultra_get_gamma2_size(nLength - 1);
+ }
+}
+
+/**
+ * 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 nArrivalsPerPosition maximum number of arrivals per input buffer position
+ * @param nDepth current insertion depth
+ */
+static void apultra_insert_forward_match(apultra_compressor *pCompressor, const unsigned char *pInWindow, const int i, const int nMatchOffset, const int nStartOffset, const int nEndOffset, const int nArrivalsPerPosition, int nDepth) {
+ const apultra_arrival *arrival = pCompressor->arrival + ((i - nStartOffset) * nArrivalsPerPosition);
+ const int *rle_len = (int*)pCompressor->intervals /* reuse */;
+ int* visited = ((int*)pCompressor->pos_data) - nStartOffset /* reuse */;
+ int j;
+
+ for (j = 0; j < nArrivalsPerPosition && arrival[j].from_slot; j++) {
+ if (arrival[j].follows_literal) {
+ int nRepOffset = arrival[j].rep_offset;
+
+ if (nMatchOffset != nRepOffset && nRepOffset) {
+ int nRepPos = arrival[j].rep_pos;
+
+ if (nRepPos >= nStartOffset &&
+ nRepPos < nEndOffset &&
+ visited[nRepPos] != nMatchOffset) {
+
+ visited[nRepPos] = nMatchOffset;
+
+ if (nRepPos >= nMatchOffset && pCompressor->match[((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT) + NMATCHES_PER_INDEX - 1].length == 0) {
+ const unsigned char* pInWindowAtRepOffset = pInWindow + nRepPos;
+
+ if (pInWindowAtRepOffset[0] == pInWindowAtRepOffset[-nMatchOffset]) {
+ int nLen0 = rle_len[nRepPos - nMatchOffset];
+ int nLen1 = rle_len[nRepPos];
+ int nMinLen = (nLen0 < nLen1) ? nLen0 : nLen1;
+
+ int nMaxRepLen = nEndOffset - nRepPos;
+ if (nMaxRepLen > LCP_MAX)
+ nMaxRepLen = LCP_MAX;
+
+ if (nMinLen > nMaxRepLen)
+ nMinLen = nMaxRepLen;
+
+ const unsigned char* pInWindowMax = pInWindowAtRepOffset + nMaxRepLen;
+ pInWindowAtRepOffset += nMinLen;
+
+ while ((pInWindowAtRepOffset + 8) < pInWindowMax && !memcmp(pInWindowAtRepOffset, pInWindowAtRepOffset - nMatchOffset, 8))
+ pInWindowAtRepOffset += 8;
+ while ((pInWindowAtRepOffset + 4) < pInWindowMax && !memcmp(pInWindowAtRepOffset, pInWindowAtRepOffset - nMatchOffset, 4))
+ pInWindowAtRepOffset += 4;
+ while (pInWindowAtRepOffset < pInWindowMax && pInWindowAtRepOffset[0] == pInWindowAtRepOffset[-nMatchOffset])
+ pInWindowAtRepOffset++;
+
+ int nCurRepLen = (int)(pInWindowAtRepOffset - (pInWindow + nRepPos));
+
+ if (nCurRepLen >= 2) {
+ apultra_match* fwd_match = pCompressor->match + ((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT);
+ unsigned short* fwd_depth = pCompressor->match_depth + ((nRepPos - nStartOffset) << MATCHES_PER_INDEX_SHIFT);
+ int r;
+
+ for (r = 0; fwd_match[r].length >= MIN_MATCH_SIZE; r++) {
+ if (fwd_match[r].offset == nMatchOffset && (fwd_depth[r] & 0x3fff) == 0) {
+ if ((int)fwd_match[r].length < nCurRepLen) {
+ fwd_match[r].length = nCurRepLen;
+ fwd_depth[r] = 0;
+ }
+ r = NMATCHES_PER_INDEX;
+ break;
+ }
+ }
+
+ if (r < NMATCHES_PER_INDEX) {
+ fwd_match[r].offset = nMatchOffset;
+ fwd_match[r].length = nCurRepLen;
+ fwd_depth[r] = 0;
+
+ if (nDepth < 9)
+ apultra_insert_forward_match(pCompressor, pInWindow, nRepPos, nMatchOffset, nStartOffset, nEndOffset, nArrivalsPerPosition, nDepth + 1);
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+/**
+ * Attempt to pick optimal matches, 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 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 nInsertForwardReps non-zero to insert forward repmatch candidates, zero to use the previously inserted candidates
+ * @param nCurRepMatchOffset starting rep offset for this block
+ * @param nBlockFlags bit 0: 1 for first block, 0 otherwise; bit 1: 1 for last block, 0 otherwise
+ * @param nArrivalsPerPosition maximum number of arrivals per input buffer position
+ */
+static void apultra_optimize_forward(apultra_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, const int nInsertForwardReps, const int *nCurRepMatchOffset, const int nBlockFlags, const int nArrivalsPerPosition) {
+ apultra_arrival *arrival = pCompressor->arrival - (nStartOffset * nArrivalsPerPosition);
+ const int* rle_len = (int*)pCompressor->intervals /* reuse */;
+ int* visited = ((int*)pCompressor->pos_data) - nStartOffset /* reuse */;
+ int i, j, n;
+
+ if ((nEndOffset - nStartOffset) > pCompressor->block_size) return;
+
+ memset(arrival + (nStartOffset * nArrivalsPerPosition), 0, sizeof(apultra_arrival) * ((nEndOffset - nStartOffset + 1) * nArrivalsPerPosition));
+
+ arrival[nStartOffset * nArrivalsPerPosition].from_slot = -1;
+ arrival[nStartOffset * nArrivalsPerPosition].rep_offset = *nCurRepMatchOffset;
+
+ for (i = (nStartOffset * nArrivalsPerPosition); i != ((nEndOffset+1) * nArrivalsPerPosition); i++) {
+ arrival[i].cost = 0x40000000;
+ }
+
+ if (nInsertForwardReps) {
+ memset(visited + nStartOffset, 0, (nEndOffset - nStartOffset) * sizeof(int));
+ }
+
+ for (i = nStartOffset; i != nEndOffset; i++) {
+ apultra_arrival *cur_arrival = &arrival[i * nArrivalsPerPosition];
+ int m;
+
+ const unsigned char nMatch1Offs = pCompressor->match1[i - nStartOffset];
+ int nShortOffset;
+ int nShortLen;
+ int nLiteralScore;
+ int nLiteralCost;
+
+ if ((pInWindow[i] != 0 && nMatch1Offs == 0) || (i == nStartOffset && (nBlockFlags & 1))) {
+ nShortOffset = 0;
+ nShortLen = 0;
+ nLiteralCost = 9 /* literal bit + literal byte */;
+ }
+ else {
+ nShortOffset = (pInWindow[i] == 0) ? 0 : nMatch1Offs;
+ nShortLen = 1;
+ nLiteralCost = 4 + TOKEN_SIZE_4BIT_MATCH /* command and offset cost; no length cost */;
+ }
+
+ nLiteralScore = nShortOffset ? 3 : 1;
+
+ if (cur_arrival[nArrivalsPerPosition].from_slot) {
+ for (j = 0; j < nArrivalsPerPosition && cur_arrival[j].from_slot; j++) {
+ int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nCodingChoiceCost = nPrevCost + nLiteralCost;
+ int nScore = cur_arrival[j].score + nLiteralScore;
+
+ apultra_arrival* pDestSlots = &cur_arrival[nArrivalsPerPosition];
+ if (nCodingChoiceCost < pDestSlots[nArrivalsPerPosition - 1].cost ||
+ (nCodingChoiceCost == pDestSlots[nArrivalsPerPosition - 1].cost && nScore < pDestSlots[nArrivalsPerPosition - 1].score)) {
+ 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) {
+ for (;
+ n < nArrivalsPerPosition && pDestSlots[n].cost == nCodingChoiceCost && nScore >= pDestSlots[n].score;
+ 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;
+ }
+
+ apultra_arrival* pDestArrival = &pDestSlots[n];
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(apultra_arrival) * (z - n));
+
+ pDestArrival->cost = nCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->follows_literal = 1;
+ pDestArrival->rep_offset = nRepOffset;
+ pDestArrival->short_offset = nShortOffset;
+ pDestArrival->rep_pos = cur_arrival[j].rep_pos;
+ pDestArrival->match_len = nShortLen;
+ pDestArrival->score = nScore;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ else {
+ for (j = 0; j < nArrivalsPerPosition && cur_arrival[j].from_slot; j++) {
+ int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nCodingChoiceCost = nPrevCost + nLiteralCost;
+ int nScore = cur_arrival[j].score + nLiteralScore;
+
+ apultra_arrival* pDestArrival = &cur_arrival[nArrivalsPerPosition + j];
+
+ pDestArrival->cost = nCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->follows_literal = 1;
+ pDestArrival->rep_offset = cur_arrival[j].rep_offset;
+ pDestArrival->short_offset = nShortOffset;
+ pDestArrival->rep_pos = cur_arrival[j].rep_pos;
+ pDestArrival->match_len = nShortLen;
+ pDestArrival->score = nScore;
+ }
+ }
+
+ if (i == nStartOffset && (nBlockFlags & 1)) continue;
+
+ const apultra_match *match = pCompressor->match + ((i - nStartOffset) << MATCHES_PER_INDEX_SHIFT);
+ const unsigned short *match_depth = pCompressor->match_depth + ((i - nStartOffset) << MATCHES_PER_INDEX_SHIFT);
+ int nNumArrivalsForThisPos = j, nOverallMinRepLen = 0, nOverallMaxRepLen = 0;
+
+ int nRepLenForArrival[NARRIVALS_PER_POSITION_MAX];
+ memset(nRepLenForArrival, 0, nArrivalsPerPosition * sizeof(int));
+
+ int nRepMatchArrivalIdx[NARRIVALS_PER_POSITION_MAX + 1];
+ int nNumRepMatchArrivals = 0;
+
+ int nMaxRepLenForPos = nEndOffset - i;
+ if (nMaxRepLenForPos > LCP_MAX)
+ nMaxRepLenForPos = LCP_MAX;
+ const unsigned char* pInWindowStart = pInWindow + i;
+ const unsigned char* pInWindowMax = pInWindowStart + nMaxRepLenForPos;
+ const int nLen1 = rle_len[i];
+
+ for (j = 0; j < nNumArrivalsForThisPos && (i + 2) <= nEndOffset; j++) {
+ if (cur_arrival[j].follows_literal) {
+ int nRepOffset = cur_arrival[j].rep_offset;
+
+ if (nRepOffset && i >= nRepOffset) {
+ if (pInWindowStart[0] == pInWindowStart[-nRepOffset]) {
+ int nLen0 = rle_len[i - nRepOffset];
+ int nMinLen = (nLen0 < nLen1) ? nLen0 : nLen1;
+
+ if (nMinLen > nMaxRepLenForPos)
+ nMinLen = nMaxRepLenForPos;
+
+ const unsigned char* pInWindowAtRepOffset = pInWindowStart + nMinLen;
+ while ((pInWindowAtRepOffset + 8) < pInWindowMax && !memcmp(pInWindowAtRepOffset, pInWindowAtRepOffset - nRepOffset, 8))
+ pInWindowAtRepOffset += 8;
+ while ((pInWindowAtRepOffset + 4) < pInWindowMax && !memcmp(pInWindowAtRepOffset, pInWindowAtRepOffset - nRepOffset, 4))
+ pInWindowAtRepOffset += 4;
+ while (pInWindowAtRepOffset < pInWindowMax && pInWindowAtRepOffset[0] == pInWindowAtRepOffset[-nRepOffset])
+ pInWindowAtRepOffset++;
+
+ int nCurMaxLen = (int)(pInWindowAtRepOffset - pInWindowStart);
+
+ if (nCurMaxLen >= 2) {
+ nRepLenForArrival[j] = nCurMaxLen;
+ nRepMatchArrivalIdx[nNumRepMatchArrivals++] = j;
+
+ if (nOverallMaxRepLen < nCurMaxLen)
+ nOverallMaxRepLen = nCurMaxLen;
+ }
+ }
+ }
+ }
+ }
+ nRepMatchArrivalIdx[nNumRepMatchArrivals] = -1;
+
+ for (m = 0; m < NMATCHES_PER_INDEX && match[m].length; m++) {
+ const int nOrigMatchLen = match[m].length;
+ const int nOrigMatchOffset = match[m].offset;
+ const unsigned int nOrigMatchDepth = match_depth[m] & 0x3fff;
+ const int nScorePenalty = 3 + ((match_depth[m] & 0x8000) >> 15);
+ unsigned int d;
+
+ for (d = 0; d <= nOrigMatchDepth; d += (nOrigMatchDepth ? nOrigMatchDepth : 1)) {
+ const int nMatchOffset = nOrigMatchOffset - d;
+ int nMatchLen = nOrigMatchLen - d;
+
+ if ((i + nMatchLen) > nEndOffset)
+ nMatchLen = nEndOffset - i;
+
+ if (nInsertForwardReps) {
+ apultra_insert_forward_match(pCompressor, pInWindow, i, nMatchOffset, nStartOffset, nEndOffset, nArrivalsPerPosition, 0);
+ }
+
+ if (nMatchLen >= 2) {
+ int nStartingMatchLen, nJumpMatchLen, k;
+ int nNoRepMatchOffsetCostForLit[2], nNoRepMatchOffsetCostDelta;
+ int nMinMatchLenForOffset;
+ int nNoRepCostAdjusment = (nMatchLen >= LCP_MAX) ? 1 : 0;
+
+ if (nMatchOffset < MINMATCH3_OFFSET)
+ nMinMatchLenForOffset = 2;
+ else {
+ if (nMatchOffset < MINMATCH4_OFFSET)
+ nMinMatchLenForOffset = 3;
+ else
+ nMinMatchLenForOffset = 4;
+ }
+
+ if (nMatchLen >= LEAVE_ALONE_MATCH_SIZE && i >= nMatchLen)
+ nStartingMatchLen = nMatchLen;
+ else
+ nStartingMatchLen = 2;
+
+ if ((nBlockFlags & 3) == 3 && nMatchLen > 90 && i >= 90)
+ nJumpMatchLen = 90;
+ else
+ nJumpMatchLen = nMatchLen + 1;
+
+ if (nStartingMatchLen <= 3 && nMatchOffset < 128) {
+ nNoRepMatchOffsetCostForLit[0] = 8 + TOKEN_SIZE_7BIT_MATCH;
+ nNoRepMatchOffsetCostForLit[1] = 8 + TOKEN_SIZE_7BIT_MATCH;
+ }
+ else {
+ nNoRepMatchOffsetCostForLit[0] = 8 + TOKEN_SIZE_LARGE_MATCH + apultra_get_gamma2_size((nMatchOffset >> 8) + 2);
+ nNoRepMatchOffsetCostForLit[1] = 8 + TOKEN_SIZE_LARGE_MATCH + apultra_get_gamma2_size((nMatchOffset >> 8) + 3);
+ }
+ nNoRepMatchOffsetCostDelta = nNoRepMatchOffsetCostForLit[1] - nNoRepMatchOffsetCostForLit[0];
+
+ for (k = nStartingMatchLen; k <= nMatchLen; k++) {
+ int nRepMatchMatchLenCost = apultra_get_gamma2_size(k);
+ apultra_arrival *pDestSlots = &cur_arrival[k * nArrivalsPerPosition];
+
+ /* Insert non-repmatch candidate */
+
+ if (k >= nMinMatchLenForOffset) {
+ int nNoRepMatchMatchLenCost;
+
+ if (k <= 3 && nMatchOffset < 128)
+ nNoRepMatchMatchLenCost = 0;
+ else {
+ if (nMatchOffset < 128 || nMatchOffset >= MINMATCH4_OFFSET)
+ nNoRepMatchMatchLenCost = apultra_get_gamma2_size(k - 2);
+ else if (nMatchOffset < MINMATCH3_OFFSET)
+ nNoRepMatchMatchLenCost = nRepMatchMatchLenCost;
+ else
+ nNoRepMatchMatchLenCost = apultra_get_gamma2_size(k - 1);
+ }
+
+ for (j = 0; j < nNumArrivalsForThisPos; j++) {
+ if (nMatchOffset != cur_arrival[j].rep_offset || cur_arrival[j].follows_literal == 0) {
+ int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nMatchCmdCost = nNoRepMatchMatchLenCost + nNoRepMatchOffsetCostForLit[cur_arrival[j].follows_literal];
+ int nCodingChoiceCost = nPrevCost + nMatchCmdCost;
+
+ if (nCodingChoiceCost <= (pDestSlots[nArrivalsPerPosition - 1].cost + 1)) {
+ int nScore = cur_arrival[j].score + nScorePenalty;
+
+ if (nCodingChoiceCost < pDestSlots[nArrivalsPerPosition - 2].cost ||
+ (nCodingChoiceCost == pDestSlots[nArrivalsPerPosition - 2].cost && nScore < pDestSlots[nArrivalsPerPosition - 2].score)) {
+ int exists = 0;
+
+ for (n = 0;
+ n < nArrivalsPerPosition && pDestSlots[n].cost < nCodingChoiceCost;
+ n++) {
+ if (pDestSlots[n].rep_offset == nMatchOffset) {
+ exists = 1;
+ break;
+ }
+ }
+
+ if (!exists) {
+ int nRevisedCodingChoiceCost = nCodingChoiceCost - nNoRepCostAdjusment;
+
+ for (;
+ n < nArrivalsPerPosition - 1 && pDestSlots[n].cost == nRevisedCodingChoiceCost && nScore >= pDestSlots[n].score;
+ 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) {
+ 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;
+ }
+
+ apultra_arrival* pDestArrival = &pDestSlots[n];
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(apultra_arrival) * (z - n));
+
+ pDestArrival->cost = nRevisedCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->follows_literal = 0;
+ pDestArrival->rep_offset = nMatchOffset;
+ pDestArrival->short_offset = 0;
+ pDestArrival->rep_pos = i;
+ pDestArrival->match_len = k;
+ pDestArrival->score = nScore;
+ }
+ }
+ }
+ }
+ else {
+ if ((nCodingChoiceCost - pDestSlots[n].cost) >= nNoRepMatchOffsetCostDelta)
+ break;
+ }
+ }
+ if (cur_arrival[j].follows_literal == 0 || nNoRepMatchOffsetCostDelta == 0)
+ break;
+ }
+ else {
+ break;
+ }
+ }
+ }
+ }
+
+ /* Insert repmatch candidate */
+
+ if (k > nOverallMinRepLen && k <= nOverallMaxRepLen) {
+ int nRepMatchCmdCost = TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + nRepMatchMatchLenCost;
+ int nCurRepMatchArrival;
+
+ if (k <= 90)
+ nOverallMinRepLen = k;
+ else if (nOverallMaxRepLen == k)
+ nOverallMaxRepLen--;
+
+ for (nCurRepMatchArrival = 0; (j = nRepMatchArrivalIdx[nCurRepMatchArrival]) >= 0; nCurRepMatchArrival++) {
+ if (nRepLenForArrival[j] >= k) {
+ int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
+ int nRepCodingChoiceCost = nPrevCost + nRepMatchCmdCost;
+ int nScore = cur_arrival[j].score + 2;
+
+ if (nRepCodingChoiceCost < pDestSlots[nArrivalsPerPosition - 1].cost ||
+ (nRepCodingChoiceCost == pDestSlots[nArrivalsPerPosition - 1].cost && nScore < pDestSlots[nArrivalsPerPosition - 1].score)) {
+ 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;
+ break;
+ }
+ }
+
+ if (!exists) {
+ for (;
+ n < nArrivalsPerPosition && pDestSlots[n].cost == nRepCodingChoiceCost && nScore >= pDestSlots[n].score;
+ 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;
+ }
+
+ apultra_arrival* pDestArrival = &pDestSlots[n];
+ memmove(&pDestSlots[n + 1],
+ &pDestSlots[n],
+ sizeof(apultra_arrival) * (z - n));
+
+ pDestArrival->cost = nRepCodingChoiceCost;
+ pDestArrival->from_pos = i;
+ pDestArrival->from_slot = j + 1;
+ pDestArrival->follows_literal = 0;
+ pDestArrival->rep_offset = nRepOffset;
+ pDestArrival->short_offset = 0;
+ pDestArrival->rep_pos = i;
+ pDestArrival->match_len = k;
+ pDestArrival->score = nScore;
+ }
+ }
+ }
+ }
+ }
+ else {
+ break;
+ }
+ }
+ }
+ }
+
+ if (k == 3 && nMatchOffset < 128) {
+ nNoRepMatchOffsetCostForLit[0] = 8 + TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size((nMatchOffset >> 8) + 2) */;
+ nNoRepMatchOffsetCostForLit[1] = 8 + TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size((nMatchOffset >> 8) + 3) */;
+ }
+
+ if (k == nJumpMatchLen)
+ k = nMatchLen - 1;
+ }
+ }
+
+ if (nOrigMatchLen >= 512)
+ break;
+ }
+ }
+ }
+
+ if (!nInsertForwardReps) {
+ const apultra_arrival* end_arrival = &arrival[(i * nArrivalsPerPosition) + 0];
+ apultra_final_match* pBestMatch = pCompressor->best_match - nStartOffset;
+
+ while (end_arrival->from_slot > 0 && end_arrival->from_pos >= 0 && (int)end_arrival->from_pos < nEndOffset) {
+ pBestMatch[end_arrival->from_pos].length = end_arrival->match_len;
+ if (end_arrival->match_len >= 2)
+ pBestMatch[end_arrival->from_pos].offset = end_arrival->rep_offset;
+ else
+ pBestMatch[end_arrival->from_pos].offset = end_arrival->short_offset;
+
+ end_arrival = &arrival[(end_arrival->from_pos * nArrivalsPerPosition) + (end_arrival->from_slot - 1)];
+ }
+ }
+}
+
+/**
+ * Attempt to replace matches by literals when it makes the final bitstream smaller, and merge large matches
+ *
+ * @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
+ * @param nCurRepMatchOffset starting rep offset for this block
+ * @param nBlockFlags bit 0: 1 for first block, 0 otherwise; bit 1: 1 for last block, 0 otherwise
+ *
+ * @return non-zero if the number of tokens was reduced, 0 if it wasn't
+ */
+static int apultra_reduce_commands(apultra_compressor *pCompressor, const unsigned char *pInWindow, apultra_final_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int *nCurRepMatchOffset, const int nBlockFlags) {
+ int i;
+ int nRepMatchOffset = *nCurRepMatchOffset;
+ int nFollowsLiteral = 0;
+ int nDidReduce = 0;
+ int nLastMatchLen = 0;
+ const unsigned char *match1 = pCompressor->match1 - nStartOffset;
+
+ for (i = nStartOffset + ((nBlockFlags & 1) ? 1 : 0); i < nEndOffset; ) {
+ apultra_final_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length <= 1 &&
+ (i + 1) < nEndOffset &&
+ pBestMatch[i + 1].length >= 2 &&
+ 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)) {
+ if ((pBestMatch[i + 1].offset < MINMATCH3_OFFSET || (pBestMatch[i + 1].length + 1) >= 3 || (pBestMatch[i + 1].offset == nRepMatchOffset && nFollowsLiteral)) &&
+ (pBestMatch[i + 1].offset < MINMATCH4_OFFSET || (pBestMatch[i + 1].length + 1) >= 4 || (pBestMatch[i + 1].offset == nRepMatchOffset && nFollowsLiteral))) {
+
+ int nCurPartialCommandSize = (pMatch->length == 1) ? (TOKEN_SIZE_4BIT_MATCH + 4) : (1 /* literal bit */ + 8 /* literal size */);
+ if (pBestMatch[i + 1].offset == nRepMatchOffset /* always follows a literal, the one at the current position */) {
+ nCurPartialCommandSize += TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + apultra_get_gamma2_size(pBestMatch[i + 1].length);
+ }
+ else {
+ nCurPartialCommandSize += apultra_get_offset_varlen_size(pBestMatch[i + 1].length, pBestMatch[i + 1].offset, 1) + apultra_get_match_varlen_size(pBestMatch[i + 1].length, pBestMatch[i + 1].offset);
+ }
+
+ int nReducedPartialCommandSize;
+ if (pBestMatch[i + 1].offset == nRepMatchOffset && nFollowsLiteral) {
+ nReducedPartialCommandSize = TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + apultra_get_gamma2_size(pBestMatch[i + 1].length);
+ }
+ else {
+ nReducedPartialCommandSize = apultra_get_offset_varlen_size(pBestMatch[i + 1].length, pBestMatch[i + 1].offset, nFollowsLiteral) + apultra_get_match_varlen_size(pBestMatch[i + 1].length, pBestMatch[i + 1].offset);
+ }
+
+ if (nReducedPartialCommandSize < nCurPartialCommandSize || (nFollowsLiteral == 0 && nLastMatchLen >= LCP_MAX)) {
+ /* 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 >= 2) {
+ if (pMatch->length < 32 && /* Don't waste time considering large matches, they will always win over literals */
+ (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 nNextFollowsLiteral = 0;
+ int nCannotEncode = 0;
+
+ while (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length < 2) {
+ nNextIndex++;
+ nNextFollowsLiteral = 1;
+ }
+
+ if (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length >= 2) {
+ if (nRepMatchOffset && nRepMatchOffset != pMatch->offset && pBestMatch[nNextIndex].offset && pMatch->offset != pBestMatch[nNextIndex].offset &&
+ nNextFollowsLiteral) {
+ /* Try to gain a match forward */
+ if (i >= pBestMatch[nNextIndex].offset && (i - pBestMatch[nNextIndex].offset + pMatch->length) <= nEndOffset) {
+ if ((pBestMatch[nNextIndex].offset < MINMATCH3_OFFSET || pMatch->length >= 3) &&
+ (pBestMatch[nNextIndex].offset < MINMATCH4_OFFSET || pMatch->length >= 4)) {
+ int nMaxLen = 0;
+ const unsigned char* pInWindowAtPos = pInWindow + i;
+ while (nMaxLen < pMatch->length && pInWindowAtPos[nMaxLen - pBestMatch[nNextIndex].offset] == pInWindowAtPos[nMaxLen])
+ nMaxLen++;
+
+ if (nMaxLen >= pMatch->length) {
+ /* Replace */
+ pMatch->offset = pBestMatch[nNextIndex].offset;
+ nDidReduce = 1;
+ }
+ else if (nMaxLen >= 2) {
+ if ((nFollowsLiteral && nRepMatchOffset == pBestMatch[nNextIndex].offset) ||
+ ((pBestMatch[nNextIndex].offset < MINMATCH3_OFFSET || nMaxLen >= 3) &&
+ (pBestMatch[nNextIndex].offset < MINMATCH4_OFFSET || nMaxLen >= 4))) {
+
+ int nPartialSizeBefore, nPartialSizeAfter, j;
+
+ nPartialSizeBefore = apultra_get_offset_varlen_size(pMatch->length, pMatch->offset, nFollowsLiteral);
+ nPartialSizeBefore += apultra_get_match_varlen_size(pMatch->length, pMatch->offset);
+
+ nPartialSizeBefore += apultra_get_offset_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset, 1);
+ nPartialSizeBefore += apultra_get_match_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset);
+
+ nPartialSizeAfter = apultra_get_offset_varlen_size(nMaxLen, pBestMatch[nNextIndex].offset, nFollowsLiteral);
+ if (nFollowsLiteral && nRepMatchOffset == pBestMatch[nNextIndex].offset)
+ nPartialSizeAfter += apultra_get_gamma2_size(nMaxLen);
+ else
+ nPartialSizeAfter += apultra_get_match_varlen_size(nMaxLen, pBestMatch[nNextIndex].offset);
+
+ nPartialSizeAfter += TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */;
+ nPartialSizeAfter += apultra_get_gamma2_size(pBestMatch[nNextIndex].length);
+
+ for (j = nMaxLen; j < pMatch->length; j++) {
+ if (pInWindow[i + j] == 0 || match1[i + j])
+ nPartialSizeAfter += TOKEN_SIZE_4BIT_MATCH + 4;
+ else
+ nPartialSizeAfter += 1 /* literal bit */ + 8 /* literal byte */;
+ }
+
+ if (nPartialSizeAfter < nPartialSizeBefore) {
+ /* 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 */
+
+ int nOrigLen = pMatch->length;
+ int j;
+
+ pMatch->offset = pBestMatch[nNextIndex].offset;
+ pMatch->length = nMaxLen;
+
+ for (j = nMaxLen; j < nOrigLen; j++) {
+ pBestMatch[i + j].offset = match1[i + j];
+ pBestMatch[i + j].length = (pInWindow[i + j] && match1[i+j] == 0) ? 0 : 1;
+ }
+
+ nDidReduce = 1;
+ continue;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /* Calculate this command's current cost */
+
+ int nCurCommandSize;
+ if (pMatch->offset == nRepMatchOffset && nFollowsLiteral) {
+ nCurCommandSize = TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + apultra_get_gamma2_size(pMatch->length);
+ }
+ else {
+ nCurCommandSize = apultra_get_offset_varlen_size(pMatch->length, pMatch->offset, nFollowsLiteral) + apultra_get_match_varlen_size(pMatch->length, pMatch->offset);
+ }
+
+ /* Calculate the next command's current cost */
+ int nNextCommandSize;
+ if (pBestMatch[nNextIndex].offset == pMatch->offset && nNextFollowsLiteral && pBestMatch[nNextIndex].length >= 2) {
+ nNextCommandSize = TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + apultra_get_gamma2_size(pBestMatch[nNextIndex].length);
+ }
+ else {
+ nNextCommandSize = apultra_get_offset_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset, nNextFollowsLiteral) + apultra_get_match_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset);
+ }
+
+ int nOriginalCombinedCommandSize = nCurCommandSize + nNextCommandSize;
+
+ /* Calculate the cost of replacing this match command by literals + the effect on the cost of the next command */
+ int nReducedCommandSize = 0;
+ int j;
+
+ for (j = 0; j < pMatch->length; j++) {
+ if (pInWindow[i + j] == 0 || match1[i + j])
+ nReducedCommandSize += TOKEN_SIZE_4BIT_MATCH + 4;
+ else
+ nReducedCommandSize += 1 /* literal bit */ + 8;
+ }
+
+ if (pBestMatch[nNextIndex].offset == nRepMatchOffset /* the new command would always follow literals, the ones we create */ && pBestMatch[nNextIndex].length >= 2) {
+ nReducedCommandSize += TOKEN_SIZE_LARGE_MATCH + 2 /* apultra_get_gamma2_size(2) */ + apultra_get_gamma2_size(pBestMatch[nNextIndex].length);
+ }
+ else {
+ if ((pBestMatch[nNextIndex].length < 3 && pBestMatch[nNextIndex].offset >= MINMATCH3_OFFSET) ||
+ (pBestMatch[nNextIndex].length < 4 && pBestMatch[nNextIndex].offset >= MINMATCH4_OFFSET)) {
+ /* This match length can only be encoded with a rep-match */
+ nCannotEncode = 1;
+ }
+ else {
+ nReducedCommandSize += apultra_get_offset_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset, 1 /* follows literals */) + apultra_get_match_varlen_size(pBestMatch[nNextIndex].length, pBestMatch[nNextIndex].offset);
+ }
+ }
+
+ if (!nCannotEncode && nOriginalCombinedCommandSize > nReducedCommandSize) {
+ /* Reduce */
+ int nMatchLen = pMatch->length;
+ int j;
+
+ for (j = 0; j < nMatchLen; j++) {
+ pBestMatch[i + j].offset = match1[i + j];
+ pBestMatch[i + j].length = (pInWindow[i + j] && match1[i + j] == 0) ? 0 : 1;
+ }
+
+ nDidReduce = 1;
+ continue;
+ }
+ }
+ }
+
+ if ((i + pMatch->length) < nEndOffset && pMatch->offset > 0 &&
+ pBestMatch[i + pMatch->length].offset > 0 &&
+ pBestMatch[i + pMatch->length].length >= 2 &&
+ (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->length - pMatch->offset,
+ pInWindow + i + pMatch->length - pBestMatch[i + pMatch->length].offset,
+ pBestMatch[i + pMatch->length].length)) {
+ int nMatchLen = pMatch->length;
+
+ /* Join large matches */
+
+ int nNextIndex = i + pMatch->length + pBestMatch[i + pMatch->length].length;
+ int nNextFollowsLiteral = 0;
+ int nCannotEncode = 0;
+
+ while (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length < 2) {
+ nNextIndex++;
+ nNextFollowsLiteral = 1;
+ }
+
+ if (nNextIndex < nEndOffset && nNextFollowsLiteral && pBestMatch[nNextIndex].length >= 2 &&
+ pBestMatch[nNextIndex].offset == pBestMatch[i + pMatch->length].offset) {
+ if ((pBestMatch[nNextIndex].offset >= MINMATCH3_OFFSET && pBestMatch[nNextIndex].length < 3) ||
+ (pBestMatch[nNextIndex].offset >= MINMATCH4_OFFSET && pBestMatch[nNextIndex].length < 4)) {
+ nCannotEncode = 1;
+ }
+ }
+
+ if (!nCannotEncode) {
+ pMatch->length += pBestMatch[i + nMatchLen].length;
+ pBestMatch[i + nMatchLen].offset = 0;
+ pBestMatch[i + nMatchLen].length = -1;
+ nDidReduce = 1;
+ continue;
+ }
+ }
+
+ nRepMatchOffset = pMatch->offset;
+ nFollowsLiteral = 0;
+ nLastMatchLen = pMatch->length;
+
+ i += pMatch->length;
+ }
+ else {
+ /* 4 bits offset (1 byte match) or literal */
+ i++;
+ nFollowsLiteral = 1;
+ nLastMatchLen = 0;
+ }
+ }
+
+ return nDidReduce;
+}
+
+/**
+ * Emit a 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
+ * @param nCurBitsOffset write index into output buffer, of current byte being filled with bits
+ * @param nCurBitShift bit shift count
+ * @param nFollowsLiteral non-zero if the next command to be issued follows a literal, 0 if not
+ * @param nCurRepMatchOffset starting rep offset for this block, updated after the block is compressed successfully
+ * @param nBlockFlags bit 0: 1 for first block, 0 otherwise; bit 1: 1 for last block, 0 otherwise
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+static int apultra_write_block(apultra_compressor *pCompressor, apultra_final_match *pBestMatch, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, int nOutOffset, const int nMaxOutDataSize, int *nCurBitsOffset, int *nCurBitShift, int *nFollowsLiteral, int *nCurRepMatchOffset, const int nBlockFlags) {
+ int i;
+ int nRepMatchOffset = *nCurRepMatchOffset;
+ const int nMaxOffset = pCompressor->max_offset;
+
+ if (nBlockFlags & 1) {
+ if (nOutOffset < 0 || nOutOffset >= nMaxOutDataSize)
+ return -1;
+ pOutData[nOutOffset++] = pInWindow[nStartOffset];
+ *nFollowsLiteral = 1;
+ }
+
+ for (i = nStartOffset + ((nBlockFlags & 1) ? 1 : 0); i < nEndOffset; ) {
+ const apultra_final_match *pMatch = pBestMatch + i;
+
+ if (pMatch->length >= 2) {
+ int nMatchOffset = pMatch->offset;
+ int nMatchLen = pMatch->length;
+
+ if (nMatchOffset < MIN_OFFSET || nMatchOffset > nMaxOffset)
+ return -1;
+
+ if (nMatchOffset == nRepMatchOffset && *nFollowsLiteral) {
+ /* Rep-match */
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, TOKEN_CODE_LARGE_MATCH, TOKEN_SIZE_LARGE_MATCH, nCurBitsOffset, nCurBitShift);
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, 0 /* length of 2 encoded as gamma 2 */, 2, nCurBitsOffset, nCurBitShift);
+
+ /* The match length isn't encoded in the command, emit elias gamma value */
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, nMatchLen, nCurBitsOffset, nCurBitShift);
+ if (nOutOffset < 0) return -1;
+
+ *nFollowsLiteral = 0;
+
+ pCompressor->stats.num_rep_matches++;
+ }
+ else {
+ if (nMatchLen <= 3 && nMatchOffset < 128) {
+ /* 7 bits offset + 1 bit length */
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, TOKEN_CODE_7BIT_MATCH, TOKEN_SIZE_7BIT_MATCH, nCurBitsOffset, nCurBitShift);
+
+ if (nOutOffset < 0 || nOutOffset >= nMaxOutDataSize)
+ return -1;
+ pOutData[nOutOffset++] = ((nMatchOffset) & 0x7f) << 1 | (nMatchLen - 2);
+
+ *nFollowsLiteral = 0;
+ nRepMatchOffset = nMatchOffset;
+
+ pCompressor->stats.num_7bit_matches++;
+ }
+ else {
+ /* 8+n bits offset */
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, TOKEN_CODE_LARGE_MATCH, TOKEN_SIZE_LARGE_MATCH, nCurBitsOffset, nCurBitShift);
+
+ if (nOutOffset < 0 || nOutOffset >= nMaxOutDataSize)
+ return -1;
+ if (*nFollowsLiteral)
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, (nMatchOffset >> 8) + 3, nCurBitsOffset, nCurBitShift);
+ else
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, (nMatchOffset >> 8) + 2, nCurBitsOffset, nCurBitShift);
+ pOutData[nOutOffset++] = nMatchOffset & 0xff;
+
+ /* The match length isn't encoded in the command, emit elias gamma value */
+
+ if (nMatchOffset < 128 || nMatchOffset >= MINMATCH4_OFFSET)
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, nMatchLen - 2, nCurBitsOffset, nCurBitShift);
+ else if (nMatchOffset < MINMATCH3_OFFSET)
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, nMatchLen, nCurBitsOffset, nCurBitShift);
+ else
+ nOutOffset = apultra_write_gamma2_value(pOutData, nOutOffset, nMaxOutDataSize, nMatchLen - 1, nCurBitsOffset, nCurBitShift);
+ if (nOutOffset < 0) return -1;
+
+ *nFollowsLiteral = 0;
+ nRepMatchOffset = nMatchOffset;
+
+ pCompressor->stats.num_variable_matches++;
+ }
+ }
+
+ 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 += (long long)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;
+
+ pCompressor->stats.commands_divisor++;
+ }
+ else if (pMatch->length == 1) {
+ int nMatchOffset = pMatch->offset;
+
+ /* 4 bits offset */
+
+ if (nMatchOffset < 0 || nMatchOffset > 15)
+ return -1;
+
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, TOKEN_CODE_4BIT_MATCH, TOKEN_SIZE_4BIT_MATCH, nCurBitsOffset, nCurBitShift);
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, nMatchOffset, 4, nCurBitsOffset, nCurBitShift);
+ if (nOutOffset < 0) return -1;
+
+ pCompressor->stats.num_4bit_matches++;
+ pCompressor->stats.commands_divisor++;
+
+ i++;
+ *nFollowsLiteral = 1;
+ }
+ else {
+ /* Literal */
+
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, 0 /* literal */, 1, nCurBitsOffset, nCurBitShift);
+
+ if (nOutOffset < 0 || nOutOffset >= nMaxOutDataSize)
+ return -1;
+ pOutData[nOutOffset++] = pInWindow[i];
+
+ pCompressor->stats.num_literals++;
+ pCompressor->stats.commands_divisor++;
+ i++;
+ *nFollowsLiteral = 1;
+ }
+
+ int nCurSafeDist = (i - nStartOffset) - nOutOffset;
+ if (nCurSafeDist >= 0 && pCompressor->stats.safe_dist < nCurSafeDist)
+ pCompressor->stats.safe_dist = nCurSafeDist;
+ }
+
+ if (nBlockFlags & 2) {
+ /* 8 bits offset */
+
+ nOutOffset = apultra_write_bits(pOutData, nOutOffset, nMaxOutDataSize, TOKEN_CODE_7BIT_MATCH, TOKEN_SIZE_7BIT_MATCH, nCurBitsOffset, nCurBitShift);
+
+ if (nOutOffset < 0 || nOutOffset >= nMaxOutDataSize)
+ return -1;
+ pOutData[nOutOffset++] = 0x00; /* Offset: EOD */
+ pCompressor->stats.num_eod++;
+ pCompressor->stats.commands_divisor++;
+
+ int nCurSafeDist = (i - nStartOffset) - nOutOffset;
+ if (nCurSafeDist >= 0 && pCompressor->stats.safe_dist < nCurSafeDist)
+ pCompressor->stats.safe_dist = nCurSafeDist;
+ }
+
+ *nCurRepMatchOffset = nRepMatchOffset;
+ return nOutOffset;
+}
+
+/**
+ * Select the most optimal matches, reduce the token count if possible, and then emit a block of compressed 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
+ * @param nCurBitsOffset write index into output buffer, of current byte being filled with bits
+ * @param nCurBitShift bit shift count
+ * @param nCurFollowsLiteral non-zero if the next command to be issued follows a literal, 0 if not
+ * @param nCurRepMatchOffset starting rep offset for this block, updated after the block is compressed successfully
+ * @param nBlockFlags bit 0: 1 for first block, 0 otherwise; bit 1: 1 for last block, 0 otherwise
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+static int apultra_optimize_and_write_block(apultra_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize, int *nCurBitsOffset, int *nCurBitShift, int *nCurFollowsLiteral, int *nCurRepMatchOffset, const int nBlockFlags) {
+ int nOutOffset = 0;
+ const int nEndOffset = nPreviousBlockSize + nInDataSize;
+ const int nArrivalsPerPosition = pCompressor->max_arrivals;
+ int *rle_len = (int*)pCompressor->intervals /* reuse */;
+ int i, nPosition;
+
+ memset(pCompressor->best_match, 0, pCompressor->block_size * sizeof(apultra_final_match));
+
+ if ((nBlockFlags & 3) == 3) {
+ int *first_offset_for_byte = pCompressor->first_offset_for_byte;
+ int *next_offset_for_pos = pCompressor->next_offset_for_pos;
+
+ /* Supplement 2 and 3-byte 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++) {
+ apultra_match *match = pCompressor->match + ((nPosition - nPreviousBlockSize) << MATCHES_PER_INDEX_SHIFT);
+ unsigned short *match_depth = pCompressor->match_depth + ((nPosition - nPreviousBlockSize) << MATCHES_PER_INDEX_SHIFT);
+ 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;
+
+ if (nMatchOffset <= pCompressor->max_offset) {
+ int nExistingMatchIdx;
+ int nAlreadyExists = 0;
+
+ for (nExistingMatchIdx = 0; nExistingMatchIdx < m; nExistingMatchIdx++) {
+ if (match[nExistingMatchIdx].offset == nMatchOffset ||
+ (match[nExistingMatchIdx].offset - (match_depth[nExistingMatchIdx] & 0x3fff)) == nMatchOffset) {
+ nAlreadyExists = 1;
+ break;
+ }
+ }
+
+ if (!nAlreadyExists) {
+ match[m].length = (nPosition < (nEndOffset - 2) && pInWindow[nMatchPos + 2] == pInWindow[nPosition + 2]) ? 3 : 2;
+ match[m].offset = nMatchOffset;
+ match_depth[m] = 0x4000;
+ m++;
+ nInserted++;
+ if (nInserted >= 6)
+ break;
+ }
+ }
+ else {
+ break;
+ }
+ }
+ }
+ }
+
+ i = 0;
+ while (i < nEndOffset) {
+ int nRangeStartIdx = i;
+ unsigned char c = pInWindow[nRangeStartIdx];
+ do {
+ i++;
+ }
+ while (i < nEndOffset && pInWindow[i] == c);
+ while (nRangeStartIdx < i) {
+ rle_len[nRangeStartIdx] = i - nRangeStartIdx;
+ nRangeStartIdx++;
+ }
+ }
+
+ apultra_optimize_forward(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, 1 /* nInsertForwardReps */, nCurRepMatchOffset, nBlockFlags, nArrivalsPerPosition);
+
+ if ((nBlockFlags & 3) == 3 && nArrivalsPerPosition == NARRIVALS_PER_POSITION_MAX) {
+ const int* next_offset_for_pos = pCompressor->next_offset_for_pos;
+ int* offset_cache = pCompressor->offset_cache;
+
+ /* Supplement matches further */
+
+ memset(offset_cache, 0xff, sizeof(int) * 2048);
+
+ for (nPosition = nPreviousBlockSize + 1; nPosition < (nEndOffset - 1); nPosition++) {
+ apultra_match* match = pCompressor->match + ((nPosition - nPreviousBlockSize) << MATCHES_PER_INDEX_SHIFT);
+
+ if (match[0].length < 8) {
+ unsigned short* match_depth = pCompressor->match_depth + ((nPosition - nPreviousBlockSize) << MATCHES_PER_INDEX_SHIFT);
+ int m = 0, nInserted = 0;
+ int nMatchPos;
+
+ while (m < 42 && match[m].length) {
+ offset_cache[match[m].offset & 2047] = nPosition;
+ offset_cache[(match[m].offset - (match_depth[m] & 0x3fff)) & 2047] = nPosition;
+ m++;
+ }
+
+ for (nMatchPos = next_offset_for_pos[nPosition - nPreviousBlockSize]; m < 42 && nMatchPos >= 0; nMatchPos = next_offset_for_pos[nMatchPos - nPreviousBlockSize]) {
+ int nMatchOffset = nPosition - nMatchPos;
+
+ if (nMatchOffset <= pCompressor->max_offset) {
+ int nAlreadyExists = 0;
+
+ if (offset_cache[nMatchOffset & 2047] == nPosition) {
+ int nExistingMatchIdx;
+
+ for (nExistingMatchIdx = 0; nExistingMatchIdx < m; nExistingMatchIdx++) {
+ if (match[nExistingMatchIdx].offset == nMatchOffset ||
+ (match[nExistingMatchIdx].offset - (match_depth[nExistingMatchIdx] & 0x3fff)) == nMatchOffset) {
+ nAlreadyExists = 1;
+
+ if (match_depth[nExistingMatchIdx] == 0x4000) {
+ int nMatchLen = 2;
+ while (nMatchLen < 16 && nPosition < (nEndOffset - nMatchLen) && pInWindow[nMatchPos + nMatchLen] == pInWindow[nPosition + nMatchLen])
+ nMatchLen++;
+ if (nMatchLen > (int)match[nExistingMatchIdx].length)
+ match[nExistingMatchIdx].length = nMatchLen;
+ }
+
+ break;
+ }
+ }
+ }
+
+ if (!nAlreadyExists) {
+ int nForwardPos = nPosition + 2 + 1;
+ int nGotMatch = 0;
+
+ while (nForwardPos >= nMatchOffset && (nForwardPos + 2) < nEndOffset && nForwardPos < (nPosition + 2 + 1 + 5)) {
+ if (!memcmp(pInWindow + nForwardPos, pInWindow + nForwardPos - nMatchOffset, 2)) {
+ nGotMatch = 1;
+ break;
+ }
+ nForwardPos++;
+ }
+
+ if (nGotMatch) {
+ int nMatchLen = 2;
+ while (nMatchLen < 16 && nPosition < (nEndOffset - nMatchLen) && pInWindow[nMatchPos + nMatchLen] == pInWindow[nPosition + nMatchLen])
+ nMatchLen++;
+ match[m].length = nMatchLen;
+ match[m].offset = nMatchOffset;
+ match_depth[m] = 0;
+ m++;
+
+ apultra_insert_forward_match(pCompressor, pInWindow, nPosition, nMatchOffset, nPreviousBlockSize, nEndOffset, nArrivalsPerPosition, 8);
+
+ nInserted++;
+ if (nInserted >= 6)
+ break;
+ }
+ }
+ }
+ else {
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ /* Pick optimal matches */
+ apultra_optimize_forward(pCompressor, pInWindow, nPreviousBlockSize, nEndOffset, 0 /* nInsertForwardReps */, nCurRepMatchOffset, nBlockFlags, nArrivalsPerPosition);
+
+ /* Apply reduction and merge pass */
+ int nDidReduce;
+ int nPasses = 0;
+ do {
+ nDidReduce = apultra_reduce_commands(pCompressor, pInWindow, pCompressor->best_match - nPreviousBlockSize, nPreviousBlockSize, nEndOffset, nCurRepMatchOffset, nBlockFlags);
+ nPasses++;
+ } while (nDidReduce && nPasses < 20);
+
+ /* Write compressed block */
+
+ return apultra_write_block(pCompressor, pCompressor->best_match - nPreviousBlockSize, pInWindow, nPreviousBlockSize, nEndOffset, pOutData, nOutOffset, nMaxOutDataSize, nCurBitsOffset, nCurBitShift, nCurFollowsLiteral, nCurRepMatchOffset, nBlockFlags);
+}
+
+/* Forward declaration */
+static void apultra_compressor_destroy(apultra_compressor *pCompressor);
+
+/**
+ * Initialize compression context
+ *
+ * @param pCompressor compression context to initialize
+ * @param nBlockSize maximum size of input data (bytes to compress only)
+ * @param nMaxWindowSize maximum size of input data window (previously compressed bytes + bytes to compress)
+ * @param nMaxArrivals maximum number of arrivals per position
+ * @param nFlags compression flags
+ *
+ * @return 0 for success, non-zero for failure
+ */
+static int apultra_compressor_init(apultra_compressor *pCompressor, const int nBlockSize, const int nMaxWindowSize, const int nMaxArrivals, const int nFlags) {
+ int nResult;
+
+ nResult = divsufsort_init(&pCompressor->divsufsort_context);
+ pCompressor->intervals = NULL;
+ pCompressor->pos_data = NULL;
+ pCompressor->open_intervals = NULL;
+ pCompressor->match = NULL;
+ pCompressor->match_depth = NULL;
+ pCompressor->match1 = NULL;
+ pCompressor->best_match = NULL;
+ pCompressor->arrival = NULL;
+ pCompressor->first_offset_for_byte = NULL;
+ pCompressor->next_offset_for_pos = NULL;
+ pCompressor->offset_cache = NULL;
+ pCompressor->flags = nFlags;
+ pCompressor->block_size = nBlockSize;
+ pCompressor->max_arrivals = nMaxArrivals;
+
+ memset(&pCompressor->stats, 0, sizeof(pCompressor->stats));
+ pCompressor->stats.min_match_len = -1;
+ pCompressor->stats.min_offset = -1;
+ pCompressor->stats.min_rle1_len = -1;
+ pCompressor->stats.min_rle2_len = -1;
+
+ if (!nResult) {
+ pCompressor->intervals = (unsigned long long *)malloc(nMaxWindowSize * sizeof(unsigned long long));
+
+ if (pCompressor->intervals) {
+ pCompressor->pos_data = (unsigned long long *)malloc(nMaxWindowSize * sizeof(unsigned long long));
+
+ if (pCompressor->pos_data) {
+ pCompressor->open_intervals = (unsigned long long *)malloc((LCP_AND_TAG_MAX + 1) * sizeof(unsigned long long));
+
+ if (pCompressor->open_intervals) {
+ pCompressor->arrival = (apultra_arrival *)malloc((nBlockSize + 1) * nMaxArrivals * sizeof(apultra_arrival));
+
+ if (pCompressor->arrival) {
+ pCompressor->best_match = (apultra_final_match *)malloc(nBlockSize * sizeof(apultra_final_match));
+
+ if (pCompressor->best_match) {
+ pCompressor->match = (apultra_match *)malloc(nBlockSize * NMATCHES_PER_INDEX * sizeof(apultra_match));
+ if (pCompressor->match) {
+ pCompressor->match_depth = (unsigned short *)malloc(nBlockSize * NMATCHES_PER_INDEX * sizeof(unsigned short));
+ if (pCompressor->match_depth) {
+ pCompressor->match1 = (unsigned char *)malloc(nBlockSize * sizeof(unsigned char));
+ if (pCompressor->match1) {
+ pCompressor->first_offset_for_byte = (int*)malloc(65536 * sizeof(int));
+ if (pCompressor->first_offset_for_byte) {
+ pCompressor->next_offset_for_pos = (int*)malloc(nBlockSize * sizeof(int));
+ if (pCompressor->next_offset_for_pos) {
+ if (nMaxArrivals == NARRIVALS_PER_POSITION_MAX) {
+ pCompressor->offset_cache = (int*)malloc(2048 * sizeof(int));
+ if (pCompressor->offset_cache) {
+ return 0;
+ }
+ }
+ else {
+ return 0;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ apultra_compressor_destroy(pCompressor);
+ return 100;
+}
+
+/**
+ * Clean up compression context and free up any associated resources
+ *
+ * @param pCompressor compression context to clean up
+ */
+static void apultra_compressor_destroy(apultra_compressor *pCompressor) {
+ divsufsort_destroy(&pCompressor->divsufsort_context);
+
+ if (pCompressor->offset_cache) {
+ free(pCompressor->offset_cache);
+ pCompressor->offset_cache = NULL;
+ }
+
+ if (pCompressor->next_offset_for_pos) {
+ free(pCompressor->next_offset_for_pos);
+ pCompressor->next_offset_for_pos = NULL;
+ }
+
+ if (pCompressor->first_offset_for_byte) {
+ free(pCompressor->first_offset_for_byte);
+ pCompressor->first_offset_for_byte = NULL;
+ }
+
+ if (pCompressor->match1) {
+ free(pCompressor->match1);
+ pCompressor->match1 = NULL;
+ }
+
+ if (pCompressor->match_depth) {
+ free(pCompressor->match_depth);
+ pCompressor->match_depth = NULL;
+ }
+
+ if (pCompressor->match) {
+ free(pCompressor->match);
+ pCompressor->match = NULL;
+ }
+
+ if (pCompressor->arrival) {
+ free(pCompressor->arrival);
+ pCompressor->arrival = NULL;
+ }
+
+ if (pCompressor->best_match) {
+ free(pCompressor->best_match);
+ pCompressor->best_match = NULL;
+ }
+
+ if (pCompressor->open_intervals) {
+ free(pCompressor->open_intervals);
+ pCompressor->open_intervals = NULL;
+ }
+
+ if (pCompressor->pos_data) {
+ free(pCompressor->pos_data);
+ pCompressor->pos_data = NULL;
+ }
+
+ if (pCompressor->intervals) {
+ free(pCompressor->intervals);
+ pCompressor->intervals = NULL;
+ }
+}
+
+/**
+ * Compress one block of 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
+ * @param nCurBitsOffset write index into output buffer, of current byte being filled with bits
+ * @param nCurBitShift bit shift count
+ * @param nCurFollowsLiteral non-zero if the next command to be issued follows a literal, 0 if not
+ * @param nCurRepMatchOffset starting rep offset for this block, updated after the block is compressed successfully
+ * @param nBlockFlags bit 0: 1 for first block, 0 otherwise; bit 1: 1 for last block, 0 otherwise
+ *
+ * @return size of compressed data in output buffer, or -1 if the data is uncompressible
+ */
+static int apultra_compressor_shrink_block(apultra_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize, int *nCurBitsOffset, int *nCurBitShift, int *nCurFollowsLiteral, int *nCurRepMatchOffset, const int nBlockFlags) {
+ int nCompressedSize;
+
+ if (apultra_build_suffix_array(pCompressor, pInWindow, nPreviousBlockSize + nInDataSize))
+ nCompressedSize = -1;
+ else {
+ if (nPreviousBlockSize) {
+ apultra_skip_matches(pCompressor, 0, nPreviousBlockSize);
+ }
+ apultra_find_all_matches(pCompressor, NMATCHES_PER_INDEX, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, nBlockFlags);
+
+ nCompressedSize = apultra_optimize_and_write_block(pCompressor, pInWindow, nPreviousBlockSize, nInDataSize, pOutData, nMaxOutDataSize, nCurBitsOffset, nCurBitShift, nCurFollowsLiteral, nCurRepMatchOffset, nBlockFlags);
+ }
+
+ return nCompressedSize;
+}
+
+/**
+ * Get maximum compressed size of input(source) data
+ *
+ * @param nInputSize input(source) size in bytes
+ *
+ * @return maximum compressed size
+ */
+size_t apultra_get_max_compressed_size(size_t nInputSize) {
+ return ((nInputSize * 9 /* literals + literal bits */ + 1 /* match bit */ + 2 /* 7+1 command bits */ + 8 /* EOD offset bits */) + 7) >> 3;
+}
+
+/**
+ * Compress memory
+ *
+ * @param pInputData pointer to input(source) data to compress
+ * @param pOutBuffer buffer for compressed data
+ * @param nInputSize input(source) size in bytes
+ * @param nMaxOutBufferSize maximum capacity of compression buffer
+ * @param nFlags compression flags (set to 0)
+ * @param nMaxWindowSize maximum window size to use (0 for default)
+ * @param nDictionarySize size of dictionary in front of input data (0 for none)
+ * @param progress progress function, called after compressing each block, or NULL for none
+ * @param pStats pointer to compression stats that are filled if this function is successful, or NULL
+ *
+ * @return actual compressed size, or -1 for error
+ */
+size_t apultra_compress(const unsigned char *pInputData, unsigned char *pOutBuffer, size_t nInputSize, size_t nMaxOutBufferSize,
+ const unsigned int nFlags, size_t nMaxWindowSize, size_t nDictionarySize, void(*progress)(long long nOriginalSize, long long nCompressedSize), apultra_stats *pStats) {
+ apultra_compressor compressor;
+ size_t nOriginalSize = 0;
+ size_t nCompressedSize = 0L;
+ int nResult;
+ int nMaxArrivals = NARRIVALS_PER_POSITION_SMALL;
+ int nError = 0;
+ const int nBlockSize = (nInputSize < BLOCK_SIZE) ? ((nInputSize < 1024) ? 1024 : (int)nInputSize) : BLOCK_SIZE;
+ const int nMaxOutBlockSize = (int)apultra_get_max_compressed_size(nBlockSize);
+
+ if (nDictionarySize < nInputSize) {
+ int nInDataSize = (int)(nInputSize - nDictionarySize);
+ if (nInDataSize > nBlockSize)
+ nInDataSize = nBlockSize;
+
+ if (nInDataSize > 0 && (nDictionarySize + nInDataSize) >= nInputSize) {
+ if (nInputSize <= 65536)
+ nMaxArrivals = NARRIVALS_PER_POSITION_MAX;
+ else
+ nMaxArrivals = NARRIVALS_PER_POSITION_NORMAL;
+ }
+ }
+
+ nResult = apultra_compressor_init(&compressor, nBlockSize, nBlockSize * 2, nMaxArrivals, nFlags);
+ if (nResult != 0) {
+ return -1;
+ }
+
+ compressor.max_offset = nMaxWindowSize ? (int)nMaxWindowSize : MAX_OFFSET;
+
+ int nPreviousBlockSize = 0;
+ int nNumBlocks = 0;
+ int nCurBitsOffset = INT_MIN, nCurBitShift = 0, nCurFollowsLiteral = 0;
+ int nBlockFlags = 1;
+ int nCurRepMatchOffset = 0;
+
+ if (nDictionarySize) {
+ nOriginalSize = (int)nDictionarySize;
+ nPreviousBlockSize = (int)nDictionarySize;
+ }
+
+ while (nOriginalSize < nInputSize && !nError) {
+ int nInDataSize;
+
+ nInDataSize = (int)(nInputSize - nOriginalSize);
+ if (nInDataSize > nBlockSize)
+ nInDataSize = nBlockSize;
+
+ if (nInDataSize > 0) {
+ int nOutDataSize;
+ int nOutDataEnd = (int)(nMaxOutBufferSize - nCompressedSize);
+
+ if (nOutDataEnd > nMaxOutBlockSize)
+ nOutDataEnd = nMaxOutBlockSize;
+
+ if ((nOriginalSize + nInDataSize) >= nInputSize)
+ nBlockFlags |= 2;
+ nOutDataSize = apultra_compressor_shrink_block(&compressor, pInputData + nOriginalSize - nPreviousBlockSize, nPreviousBlockSize, nInDataSize, pOutBuffer + nCompressedSize, nOutDataEnd,
+ &nCurBitsOffset, &nCurBitShift, &nCurFollowsLiteral, &nCurRepMatchOffset, nBlockFlags);
+ nBlockFlags &= (~1);
+
+ if (nOutDataSize >= 0) {
+ /* Write compressed block */
+
+ if (!nError) {
+ nOriginalSize += nInDataSize;
+ nCompressedSize += nOutDataSize;
+ if (nCurBitsOffset != INT_MIN)
+ nCurBitsOffset -= nOutDataSize;
+ }
+ }
+ else {
+ nError = -1;
+ }
+
+ nPreviousBlockSize = nInDataSize;
+ nNumBlocks++;
+ }
+
+ if (!nError && nOriginalSize < nInputSize) {
+ if (progress)
+ progress(nOriginalSize, nCompressedSize);
+ }
+ }
+
+ if (progress)
+ progress(nOriginalSize, nCompressedSize);
+ if (pStats)
+ *pStats = compressor.stats;
+
+ apultra_compressor_destroy(&compressor);
+
+ if (nError) {
+ return -1;
+ }
+ else {
+ return nCompressedSize;
+ }
+}
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