From 30bf0f51335e87812ffeb54e9437f0b6a1514d67 Mon Sep 17 00:00:00 2001 From: "Juan J. Martinez" Date: Tue, 6 Sep 2022 07:37:20 +0100 Subject: Updated rasm to 1.7 --- tools/rasm/lzsa-master/src/matchfinder.c | 361 +++++++++++++++++++++++++++++++ 1 file changed, 361 insertions(+) create mode 100644 tools/rasm/lzsa-master/src/matchfinder.c (limited to 'tools/rasm/lzsa-master/src/matchfinder.c') diff --git a/tools/rasm/lzsa-master/src/matchfinder.c b/tools/rasm/lzsa-master/src/matchfinder.c new file mode 100644 index 0000000..3de2cfa --- /dev/null +++ b/tools/rasm/lzsa-master/src/matchfinder.c @@ -0,0 +1,361 @@ +/* + * matchfinder.c - LZ match finder implementation + * + * The following copying information applies to this specific source code file: + * + * Written in 2019 by Emmanuel Marty + * Portions written in 2014-2015 by Eric Biggers + * + * To the extent possible under law, the author(s) have dedicated all copyright + * and related and neighboring rights to this software to the public domain + * worldwide via the Creative Commons Zero 1.0 Universal Public Domain + * Dedication (the "CC0"). + * + * This software is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the CC0 for more details. + * + * You should have received a copy of the CC0 along with this software; if not + * see . + */ + +/* + * 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 + * 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 +#include +#include "matchfinder.h" +#include "format.h" +#include "lib.h" + +/** + * Hash index into TAG_BITS + * + * @param nIndex index value + * + * @return hash + */ +static inline int lzsa_get_index_tag(unsigned int nIndex) { + return (int)(((unsigned long long)nIndex * 11400714819323198485ULL) >> (64ULL - TAG_BITS)); +} + +/** + * Parse input data, build suffix array and overlaid data structures to speed up match finding + * + * @param pCompressor compression context + * @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress) + * @param nInWindowSize total input size in bytes (previously compressed bytes + bytes to compress) + * + * @return 0 for success, non-zero for failure + */ +int lzsa_build_suffix_array(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nInWindowSize) { + unsigned int *intervals = pCompressor->intervals; + + /* Build suffix array from input data */ + if (divsufsort_build_array(&pCompressor->divsufsort_context, pInWindow, (saidx_t*)intervals, nInWindowSize) != 0) { + return 100; + } + + int *PLCP = (int*)pCompressor->pos_data; /* Use temporarily */ + int *Phi = PLCP; + int nCurLen = 0; + int i, r; + + /* Compute the permuted LCP first (Kärkkäinen method) */ + Phi[intervals[0]] = -1; + for (i = 1; i < nInWindowSize; i++) + Phi[intervals[i]] = intervals[i - 1]; + for (i = 0; i < nInWindowSize; i++) { + if (Phi[i] == -1) { + PLCP[i] = 0; + continue; + } + int nMaxLen = (i > Phi[i]) ? (nInWindowSize - i) : (nInWindowSize - Phi[i]); + while (nCurLen < nMaxLen && pInWindow[i + nCurLen] == pInWindow[Phi[i] + nCurLen]) nCurLen++; + PLCP[i] = nCurLen; + if (nCurLen > 0) + nCurLen--; + } + + /* Rotate permuted LCP into the LCP. This has better cache locality than the direct Kasai LCP method. This also + * saves us from having to build the inverse suffix array index, as the LCP is calculated without it using this method, + * and the interval builder below doesn't need it either. */ + intervals[0] &= POS_MASK; + int nMinMatchSize = pCompressor->min_match_size; + + if (pCompressor->format_version >= 2) { + for (i = 1; i < nInWindowSize; i++) { + int nIndex = (int)(intervals[i] & POS_MASK); + int nLen = PLCP[nIndex]; + if (nLen < nMinMatchSize) + nLen = 0; + if (nLen > LCP_MAX) + nLen = LCP_MAX; + int nTaggedLen = 0; + if (nLen) + nTaggedLen = (nLen << TAG_BITS) | (lzsa_get_index_tag((unsigned int)nIndex) & ((1 << TAG_BITS) - 1)); + intervals[i] = ((unsigned int)nIndex) | (((unsigned int)nTaggedLen) << LCP_SHIFT); + } + } + else { + for (i = 1; i < nInWindowSize; i++) { + int nIndex = (int)(intervals[i] & POS_MASK); + int nLen = PLCP[nIndex]; + if (nLen < nMinMatchSize) + nLen = 0; + if (nLen > LCP_AND_TAG_MAX) + nLen = LCP_AND_TAG_MAX; + intervals[i] = ((unsigned int)nIndex) | (((unsigned int)nLen) << LCP_SHIFT); + } + } + + /** + * Build intervals for finding matches + * + * Methodology and code fragment taken from wimlib (CC0 license): + * https://wimlib.net/git/?p=wimlib;a=blob_plain;f=src/lcpit_matchfinder.c;h=a2d6a1e0cd95200d1f3a5464d8359d5736b14cbe;hb=HEAD + */ + unsigned int * const SA_and_LCP = intervals; + unsigned int *pos_data = pCompressor->pos_data; + unsigned int next_interval_idx; + unsigned int *top = pCompressor->open_intervals; + unsigned int prev_pos = SA_and_LCP[0] & POS_MASK; + + *top = 0; + intervals[0] = 0; + next_interval_idx = 1; + + for (r = 1; r < nInWindowSize; r++) { + const unsigned int next_pos = SA_and_LCP[r] & POS_MASK; + const unsigned int next_lcp = SA_and_LCP[r] & LCP_MASK; + const unsigned int top_lcp = *top & LCP_MASK; + + if (next_lcp == top_lcp) { + /* Continuing the deepest open interval */ + pos_data[prev_pos] = *top; + } + else if (next_lcp > top_lcp) { + /* Opening a new interval */ + *++top = next_lcp | next_interval_idx++; + pos_data[prev_pos] = *top; + } + else { + /* Closing the deepest open interval */ + pos_data[prev_pos] = *top; + for (;;) { + const unsigned int closed_interval_idx = *top-- & POS_MASK; + const unsigned int superinterval_lcp = *top & LCP_MASK; + + if (next_lcp == superinterval_lcp) { + /* Continuing the superinterval */ + intervals[closed_interval_idx] = *top; + break; + } + else if (next_lcp > superinterval_lcp) { + /* Creating a new interval that is a + * superinterval of the one being + * closed, but still a subinterval of + * its superinterval */ + *++top = next_lcp | next_interval_idx++; + intervals[closed_interval_idx] = *top; + break; + } + else { + /* Also closing the superinterval */ + intervals[closed_interval_idx] = *top; + } + } + } + prev_pos = next_pos; + } + + /* Close any still-open intervals. */ + pos_data[prev_pos] = *top; + for (; top > pCompressor->open_intervals; top--) + intervals[*top & POS_MASK] = *(top - 1); + + /* Success */ + return 0; +} + +/** + * Find matches at the specified offset in the input window + * + * @param pCompressor compression context + * @param nOffset offset to find matches at, in the input window + * @param pMatches pointer to returned matches + * @param nMaxMatches maximum number of matches to return (0 for none) + * @param nInWindowSize total input size in bytes (previously compressed bytes + bytes to compress) + * + * @return number of matches + */ +int lzsa_find_matches_at(lzsa_compressor *pCompressor, const int nOffset, lzsa_match *pMatches, const int nMaxMatches, const int nInWindowSize) { + unsigned int *intervals = pCompressor->intervals; + unsigned int *pos_data = pCompressor->pos_data; + unsigned int ref; + unsigned int super_ref; + unsigned int match_pos; + lzsa_match *matchptr; + int nPrevOffset = 0; + + /** + * Find matches using intervals + * + * Taken from wimlib (CC0 license): + * https://wimlib.net/git/?p=wimlib;a=blob_plain;f=src/lcpit_matchfinder.c;h=a2d6a1e0cd95200d1f3a5464d8359d5736b14cbe;hb=HEAD + */ + + /* Get the deepest lcp-interval containing the current suffix. */ + ref = pos_data[nOffset]; + + pos_data[nOffset] = 0; + + /* Ascend until we reach a visited interval, the root, or a child of the + * root. Link unvisited intervals to the current suffix as we go. */ + while ((super_ref = intervals[ref & POS_MASK]) & LCP_MASK) { + intervals[ref & POS_MASK] = nOffset | VISITED_FLAG; + ref = super_ref; + } + + if (super_ref == 0) { + /* In this case, the current interval may be any of: + * (1) the root; + * (2) an unvisited child of the root */ + + if (ref != 0) /* Not the root? */ + intervals[ref & POS_MASK] = nOffset | VISITED_FLAG; + return 0; + } + + /* Ascend indirectly via pos_data[] links. */ + match_pos = super_ref & EXCL_VISITED_MASK; + matchptr = pMatches; + + if (pCompressor->format_version >= 2 && nInWindowSize < 65536) { + if ((matchptr - pMatches) < nMaxMatches) { + int nMatchOffset = (int)(nOffset - match_pos); + + if (nMatchOffset <= MAX_OFFSET) { + matchptr->length = (unsigned short)(ref >> (LCP_SHIFT + TAG_BITS)); + matchptr->offset = (unsigned short)nMatchOffset; + matchptr++; + + nPrevOffset = nMatchOffset; + } + } + } + + for (;;) { + if ((super_ref = pos_data[match_pos]) > ref) { + match_pos = intervals[super_ref & POS_MASK] & EXCL_VISITED_MASK; + + if (pCompressor->format_version >= 2 && nInWindowSize < 65536) { + if ((matchptr - pMatches) < nMaxMatches) { + int nMatchOffset = (int)(nOffset - match_pos); + + if (nMatchOffset <= MAX_OFFSET && nMatchOffset != nPrevOffset) { + matchptr->length = ((unsigned short)(ref >> (LCP_SHIFT + TAG_BITS))) | 0x8000; + matchptr->offset = (unsigned short)nMatchOffset; + matchptr++; + + nPrevOffset = nMatchOffset; + } + } + } + } + + while ((super_ref = pos_data[match_pos]) > ref) + match_pos = intervals[super_ref & POS_MASK] & EXCL_VISITED_MASK; + intervals[ref & POS_MASK] = nOffset | VISITED_FLAG; + pos_data[match_pos] = ref; + + if ((matchptr - pMatches) < nMaxMatches) { + int nMatchOffset = (int)(nOffset - match_pos); + + if (nMatchOffset <= MAX_OFFSET && nMatchOffset != nPrevOffset) { + if (pCompressor->format_version >= 2) { + matchptr->length = (unsigned short)(ref >> (LCP_SHIFT + TAG_BITS)); + } + else { + matchptr->length = (unsigned short)(ref >> LCP_SHIFT); + } + matchptr->offset = (unsigned short)nMatchOffset; + matchptr++; + } + } + + if (super_ref == 0) + break; + ref = super_ref; + match_pos = intervals[ref & POS_MASK] & EXCL_VISITED_MASK; + + if (pCompressor->format_version >= 2 && nInWindowSize < 65536) { + if ((matchptr - pMatches) < nMaxMatches) { + int nMatchOffset = (int)(nOffset - match_pos); + + if (nMatchOffset <= MAX_OFFSET && nMatchOffset != nPrevOffset) { + matchptr->length = ((unsigned short)(ref >> (LCP_SHIFT + TAG_BITS))) | 0x8000; + matchptr->offset = (unsigned short)nMatchOffset; + + if ((matchptr->length & 0x7fff) > 2) { + matchptr++; + + nPrevOffset = nMatchOffset; + } + } + } + } + } + + return (int)(matchptr - pMatches); +} + +/** + * Skip previously compressed bytes + * + * @param pCompressor compression context + * @param nStartOffset current offset in input window (typically 0) + * @param nEndOffset offset to skip to in input window (typically the number of previously compressed bytes) + */ +void lzsa_skip_matches(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset) { + lzsa_match match; + int i; + + /* Skipping still requires scanning for matches, as this also performs a lazy update of the intervals. However, + * we don't store the matches. */ + for (i = nStartOffset; i < nEndOffset; i++) { + lzsa_find_matches_at(pCompressor, i, &match, 0, 0); + } +} + +/** + * Find all matches for the data to be compressed + * + * @param pCompressor compression context + * @param nMatchesPerOffset maximum number of matches to store for each offset + * @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 + */ +void lzsa_find_all_matches(lzsa_compressor *pCompressor, const int nMatchesPerOffset, const int nStartOffset, const int nEndOffset) { + lzsa_match *pMatch = pCompressor->match; + int i; + + for (i = nStartOffset; i < nEndOffset; i++) { + int nMatches = lzsa_find_matches_at(pCompressor, i, pMatch, nMatchesPerOffset, nEndOffset - nStartOffset); + + while (nMatches < nMatchesPerOffset) { + pMatch[nMatches].length = 0; + pMatch[nMatches].offset = 0; + nMatches++; + } + + pMatch += nMatchesPerOffset; + } +} -- cgit v1.2.3