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-rw-r--r--src/zstd/lib/compress/zstd_ldm.c619
1 files changed, 619 insertions, 0 deletions
diff --git a/src/zstd/lib/compress/zstd_ldm.c b/src/zstd/lib/compress/zstd_ldm.c
new file mode 100644
index 000000000..8c4794835
--- /dev/null
+++ b/src/zstd/lib/compress/zstd_ldm.c
@@ -0,0 +1,619 @@
+/*
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "zstd_ldm.h"
+
+#include "../common/debug.h"
+#include "zstd_fast.h" /* ZSTD_fillHashTable() */
+#include "zstd_double_fast.h" /* ZSTD_fillDoubleHashTable() */
+
+#define LDM_BUCKET_SIZE_LOG 3
+#define LDM_MIN_MATCH_LENGTH 64
+#define LDM_HASH_RLOG 7
+#define LDM_HASH_CHAR_OFFSET 10
+
+void ZSTD_ldm_adjustParameters(ldmParams_t* params,
+ ZSTD_compressionParameters const* cParams)
+{
+ params->windowLog = cParams->windowLog;
+ ZSTD_STATIC_ASSERT(LDM_BUCKET_SIZE_LOG <= ZSTD_LDM_BUCKETSIZELOG_MAX);
+ DEBUGLOG(4, "ZSTD_ldm_adjustParameters");
+ if (!params->bucketSizeLog) params->bucketSizeLog = LDM_BUCKET_SIZE_LOG;
+ if (!params->minMatchLength) params->minMatchLength = LDM_MIN_MATCH_LENGTH;
+ if (cParams->strategy >= ZSTD_btopt) {
+ /* Get out of the way of the optimal parser */
+ U32 const minMatch = MAX(cParams->targetLength, params->minMatchLength);
+ assert(minMatch >= ZSTD_LDM_MINMATCH_MIN);
+ assert(minMatch <= ZSTD_LDM_MINMATCH_MAX);
+ params->minMatchLength = minMatch;
+ }
+ if (params->hashLog == 0) {
+ params->hashLog = MAX(ZSTD_HASHLOG_MIN, params->windowLog - LDM_HASH_RLOG);
+ assert(params->hashLog <= ZSTD_HASHLOG_MAX);
+ }
+ if (params->hashRateLog == 0) {
+ params->hashRateLog = params->windowLog < params->hashLog
+ ? 0
+ : params->windowLog - params->hashLog;
+ }
+ params->bucketSizeLog = MIN(params->bucketSizeLog, params->hashLog);
+}
+
+size_t ZSTD_ldm_getTableSize(ldmParams_t params)
+{
+ size_t const ldmHSize = ((size_t)1) << params.hashLog;
+ size_t const ldmBucketSizeLog = MIN(params.bucketSizeLog, params.hashLog);
+ size_t const ldmBucketSize = ((size_t)1) << (params.hashLog - ldmBucketSizeLog);
+ size_t const totalSize = ZSTD_cwksp_alloc_size(ldmBucketSize)
+ + ZSTD_cwksp_alloc_size(ldmHSize * sizeof(ldmEntry_t));
+ return params.enableLdm ? totalSize : 0;
+}
+
+size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize)
+{
+ return params.enableLdm ? (maxChunkSize / params.minMatchLength) : 0;
+}
+
+/** ZSTD_ldm_getSmallHash() :
+ * numBits should be <= 32
+ * If numBits==0, returns 0.
+ * @return : the most significant numBits of value. */
+static U32 ZSTD_ldm_getSmallHash(U64 value, U32 numBits)
+{
+ assert(numBits <= 32);
+ return numBits == 0 ? 0 : (U32)(value >> (64 - numBits));
+}
+
+/** ZSTD_ldm_getChecksum() :
+ * numBitsToDiscard should be <= 32
+ * @return : the next most significant 32 bits after numBitsToDiscard */
+static U32 ZSTD_ldm_getChecksum(U64 hash, U32 numBitsToDiscard)
+{
+ assert(numBitsToDiscard <= 32);
+ return (hash >> (64 - 32 - numBitsToDiscard)) & 0xFFFFFFFF;
+}
+
+/** ZSTD_ldm_getTag() ;
+ * Given the hash, returns the most significant numTagBits bits
+ * after (32 + hbits) bits.
+ *
+ * If there are not enough bits remaining, return the last
+ * numTagBits bits. */
+static U32 ZSTD_ldm_getTag(U64 hash, U32 hbits, U32 numTagBits)
+{
+ assert(numTagBits < 32 && hbits <= 32);
+ if (32 - hbits < numTagBits) {
+ return hash & (((U32)1 << numTagBits) - 1);
+ } else {
+ return (hash >> (32 - hbits - numTagBits)) & (((U32)1 << numTagBits) - 1);
+ }
+}
+
+/** ZSTD_ldm_getBucket() :
+ * Returns a pointer to the start of the bucket associated with hash. */
+static ldmEntry_t* ZSTD_ldm_getBucket(
+ ldmState_t* ldmState, size_t hash, ldmParams_t const ldmParams)
+{
+ return ldmState->hashTable + (hash << ldmParams.bucketSizeLog);
+}
+
+/** ZSTD_ldm_insertEntry() :
+ * Insert the entry with corresponding hash into the hash table */
+static void ZSTD_ldm_insertEntry(ldmState_t* ldmState,
+ size_t const hash, const ldmEntry_t entry,
+ ldmParams_t const ldmParams)
+{
+ BYTE* const bucketOffsets = ldmState->bucketOffsets;
+ *(ZSTD_ldm_getBucket(ldmState, hash, ldmParams) + bucketOffsets[hash]) = entry;
+ bucketOffsets[hash]++;
+ bucketOffsets[hash] &= ((U32)1 << ldmParams.bucketSizeLog) - 1;
+}
+
+/** ZSTD_ldm_makeEntryAndInsertByTag() :
+ *
+ * Gets the small hash, checksum, and tag from the rollingHash.
+ *
+ * If the tag matches (1 << ldmParams.hashRateLog)-1, then
+ * creates an ldmEntry from the offset, and inserts it into the hash table.
+ *
+ * hBits is the length of the small hash, which is the most significant hBits
+ * of rollingHash. The checksum is the next 32 most significant bits, followed
+ * by ldmParams.hashRateLog bits that make up the tag. */
+static void ZSTD_ldm_makeEntryAndInsertByTag(ldmState_t* ldmState,
+ U64 const rollingHash,
+ U32 const hBits,
+ U32 const offset,
+ ldmParams_t const ldmParams)
+{
+ U32 const tag = ZSTD_ldm_getTag(rollingHash, hBits, ldmParams.hashRateLog);
+ U32 const tagMask = ((U32)1 << ldmParams.hashRateLog) - 1;
+ if (tag == tagMask) {
+ U32 const hash = ZSTD_ldm_getSmallHash(rollingHash, hBits);
+ U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
+ ldmEntry_t entry;
+ entry.offset = offset;
+ entry.checksum = checksum;
+ ZSTD_ldm_insertEntry(ldmState, hash, entry, ldmParams);
+ }
+}
+
+/** ZSTD_ldm_countBackwardsMatch() :
+ * Returns the number of bytes that match backwards before pIn and pMatch.
+ *
+ * We count only bytes where pMatch >= pBase and pIn >= pAnchor. */
+static size_t ZSTD_ldm_countBackwardsMatch(
+ const BYTE* pIn, const BYTE* pAnchor,
+ const BYTE* pMatch, const BYTE* pBase)
+{
+ size_t matchLength = 0;
+ while (pIn > pAnchor && pMatch > pBase && pIn[-1] == pMatch[-1]) {
+ pIn--;
+ pMatch--;
+ matchLength++;
+ }
+ return matchLength;
+}
+
+/** ZSTD_ldm_fillFastTables() :
+ *
+ * Fills the relevant tables for the ZSTD_fast and ZSTD_dfast strategies.
+ * This is similar to ZSTD_loadDictionaryContent.
+ *
+ * The tables for the other strategies are filled within their
+ * block compressors. */
+static size_t ZSTD_ldm_fillFastTables(ZSTD_matchState_t* ms,
+ void const* end)
+{
+ const BYTE* const iend = (const BYTE*)end;
+
+ switch(ms->cParams.strategy)
+ {
+ case ZSTD_fast:
+ ZSTD_fillHashTable(ms, iend, ZSTD_dtlm_fast);
+ break;
+
+ case ZSTD_dfast:
+ ZSTD_fillDoubleHashTable(ms, iend, ZSTD_dtlm_fast);
+ break;
+
+ case ZSTD_greedy:
+ case ZSTD_lazy:
+ case ZSTD_lazy2:
+ case ZSTD_btlazy2:
+ case ZSTD_btopt:
+ case ZSTD_btultra:
+ case ZSTD_btultra2:
+ break;
+ default:
+ assert(0); /* not possible : not a valid strategy id */
+ }
+
+ return 0;
+}
+
+/** ZSTD_ldm_fillLdmHashTable() :
+ *
+ * Fills hashTable from (lastHashed + 1) to iend (non-inclusive).
+ * lastHash is the rolling hash that corresponds to lastHashed.
+ *
+ * Returns the rolling hash corresponding to position iend-1. */
+static U64 ZSTD_ldm_fillLdmHashTable(ldmState_t* state,
+ U64 lastHash, const BYTE* lastHashed,
+ const BYTE* iend, const BYTE* base,
+ U32 hBits, ldmParams_t const ldmParams)
+{
+ U64 rollingHash = lastHash;
+ const BYTE* cur = lastHashed + 1;
+
+ while (cur < iend) {
+ rollingHash = ZSTD_rollingHash_rotate(rollingHash, cur[-1],
+ cur[ldmParams.minMatchLength-1],
+ state->hashPower);
+ ZSTD_ldm_makeEntryAndInsertByTag(state,
+ rollingHash, hBits,
+ (U32)(cur - base), ldmParams);
+ ++cur;
+ }
+ return rollingHash;
+}
+
+void ZSTD_ldm_fillHashTable(
+ ldmState_t* state, const BYTE* ip,
+ const BYTE* iend, ldmParams_t const* params)
+{
+ DEBUGLOG(5, "ZSTD_ldm_fillHashTable");
+ if ((size_t)(iend - ip) >= params->minMatchLength) {
+ U64 startingHash = ZSTD_rollingHash_compute(ip, params->minMatchLength);
+ ZSTD_ldm_fillLdmHashTable(
+ state, startingHash, ip, iend - params->minMatchLength, state->window.base,
+ params->hashLog - params->bucketSizeLog,
+ *params);
+ }
+}
+
+
+/** ZSTD_ldm_limitTableUpdate() :
+ *
+ * Sets cctx->nextToUpdate to a position corresponding closer to anchor
+ * if it is far way
+ * (after a long match, only update tables a limited amount). */
+static void ZSTD_ldm_limitTableUpdate(ZSTD_matchState_t* ms, const BYTE* anchor)
+{
+ U32 const current = (U32)(anchor - ms->window.base);
+ if (current > ms->nextToUpdate + 1024) {
+ ms->nextToUpdate =
+ current - MIN(512, current - ms->nextToUpdate - 1024);
+ }
+}
+
+static size_t ZSTD_ldm_generateSequences_internal(
+ ldmState_t* ldmState, rawSeqStore_t* rawSeqStore,
+ ldmParams_t const* params, void const* src, size_t srcSize)
+{
+ /* LDM parameters */
+ int const extDict = ZSTD_window_hasExtDict(ldmState->window);
+ U32 const minMatchLength = params->minMatchLength;
+ U64 const hashPower = ldmState->hashPower;
+ U32 const hBits = params->hashLog - params->bucketSizeLog;
+ U32 const ldmBucketSize = 1U << params->bucketSizeLog;
+ U32 const hashRateLog = params->hashRateLog;
+ U32 const ldmTagMask = (1U << params->hashRateLog) - 1;
+ /* Prefix and extDict parameters */
+ U32 const dictLimit = ldmState->window.dictLimit;
+ U32 const lowestIndex = extDict ? ldmState->window.lowLimit : dictLimit;
+ BYTE const* const base = ldmState->window.base;
+ BYTE const* const dictBase = extDict ? ldmState->window.dictBase : NULL;
+ BYTE const* const dictStart = extDict ? dictBase + lowestIndex : NULL;
+ BYTE const* const dictEnd = extDict ? dictBase + dictLimit : NULL;
+ BYTE const* const lowPrefixPtr = base + dictLimit;
+ /* Input bounds */
+ BYTE const* const istart = (BYTE const*)src;
+ BYTE const* const iend = istart + srcSize;
+ BYTE const* const ilimit = iend - MAX(minMatchLength, HASH_READ_SIZE);
+ /* Input positions */
+ BYTE const* anchor = istart;
+ BYTE const* ip = istart;
+ /* Rolling hash */
+ BYTE const* lastHashed = NULL;
+ U64 rollingHash = 0;
+
+ while (ip <= ilimit) {
+ size_t mLength;
+ U32 const current = (U32)(ip - base);
+ size_t forwardMatchLength = 0, backwardMatchLength = 0;
+ ldmEntry_t* bestEntry = NULL;
+ if (ip != istart) {
+ rollingHash = ZSTD_rollingHash_rotate(rollingHash, lastHashed[0],
+ lastHashed[minMatchLength],
+ hashPower);
+ } else {
+ rollingHash = ZSTD_rollingHash_compute(ip, minMatchLength);
+ }
+ lastHashed = ip;
+
+ /* Do not insert and do not look for a match */
+ if (ZSTD_ldm_getTag(rollingHash, hBits, hashRateLog) != ldmTagMask) {
+ ip++;
+ continue;
+ }
+
+ /* Get the best entry and compute the match lengths */
+ {
+ ldmEntry_t* const bucket =
+ ZSTD_ldm_getBucket(ldmState,
+ ZSTD_ldm_getSmallHash(rollingHash, hBits),
+ *params);
+ ldmEntry_t* cur;
+ size_t bestMatchLength = 0;
+ U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
+
+ for (cur = bucket; cur < bucket + ldmBucketSize; ++cur) {
+ size_t curForwardMatchLength, curBackwardMatchLength,
+ curTotalMatchLength;
+ if (cur->checksum != checksum || cur->offset <= lowestIndex) {
+ continue;
+ }
+ if (extDict) {
+ BYTE const* const curMatchBase =
+ cur->offset < dictLimit ? dictBase : base;
+ BYTE const* const pMatch = curMatchBase + cur->offset;
+ BYTE const* const matchEnd =
+ cur->offset < dictLimit ? dictEnd : iend;
+ BYTE const* const lowMatchPtr =
+ cur->offset < dictLimit ? dictStart : lowPrefixPtr;
+
+ curForwardMatchLength = ZSTD_count_2segments(
+ ip, pMatch, iend,
+ matchEnd, lowPrefixPtr);
+ if (curForwardMatchLength < minMatchLength) {
+ continue;
+ }
+ curBackwardMatchLength =
+ ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
+ lowMatchPtr);
+ curTotalMatchLength = curForwardMatchLength +
+ curBackwardMatchLength;
+ } else { /* !extDict */
+ BYTE const* const pMatch = base + cur->offset;
+ curForwardMatchLength = ZSTD_count(ip, pMatch, iend);
+ if (curForwardMatchLength < minMatchLength) {
+ continue;
+ }
+ curBackwardMatchLength =
+ ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
+ lowPrefixPtr);
+ curTotalMatchLength = curForwardMatchLength +
+ curBackwardMatchLength;
+ }
+
+ if (curTotalMatchLength > bestMatchLength) {
+ bestMatchLength = curTotalMatchLength;
+ forwardMatchLength = curForwardMatchLength;
+ backwardMatchLength = curBackwardMatchLength;
+ bestEntry = cur;
+ }
+ }
+ }
+
+ /* No match found -- continue searching */
+ if (bestEntry == NULL) {
+ ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash,
+ hBits, current,
+ *params);
+ ip++;
+ continue;
+ }
+
+ /* Match found */
+ mLength = forwardMatchLength + backwardMatchLength;
+ ip -= backwardMatchLength;
+
+ {
+ /* Store the sequence:
+ * ip = current - backwardMatchLength
+ * The match is at (bestEntry->offset - backwardMatchLength)
+ */
+ U32 const matchIndex = bestEntry->offset;
+ U32 const offset = current - matchIndex;
+ rawSeq* const seq = rawSeqStore->seq + rawSeqStore->size;
+
+ /* Out of sequence storage */
+ if (rawSeqStore->size == rawSeqStore->capacity)
+ return ERROR(dstSize_tooSmall);
+ seq->litLength = (U32)(ip - anchor);
+ seq->matchLength = (U32)mLength;
+ seq->offset = offset;
+ rawSeqStore->size++;
+ }
+
+ /* Insert the current entry into the hash table */
+ ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash, hBits,
+ (U32)(lastHashed - base),
+ *params);
+
+ assert(ip + backwardMatchLength == lastHashed);
+
+ /* Fill the hash table from lastHashed+1 to ip+mLength*/
+ /* Heuristic: don't need to fill the entire table at end of block */
+ if (ip + mLength <= ilimit) {
+ rollingHash = ZSTD_ldm_fillLdmHashTable(
+ ldmState, rollingHash, lastHashed,
+ ip + mLength, base, hBits, *params);
+ lastHashed = ip + mLength - 1;
+ }
+ ip += mLength;
+ anchor = ip;
+ }
+ return iend - anchor;
+}
+
+/*! ZSTD_ldm_reduceTable() :
+ * reduce table indexes by `reducerValue` */
+static void ZSTD_ldm_reduceTable(ldmEntry_t* const table, U32 const size,
+ U32 const reducerValue)
+{
+ U32 u;
+ for (u = 0; u < size; u++) {
+ if (table[u].offset < reducerValue) table[u].offset = 0;
+ else table[u].offset -= reducerValue;
+ }
+}
+
+size_t ZSTD_ldm_generateSequences(
+ ldmState_t* ldmState, rawSeqStore_t* sequences,
+ ldmParams_t const* params, void const* src, size_t srcSize)
+{
+ U32 const maxDist = 1U << params->windowLog;
+ BYTE const* const istart = (BYTE const*)src;
+ BYTE const* const iend = istart + srcSize;
+ size_t const kMaxChunkSize = 1 << 20;
+ size_t const nbChunks = (srcSize / kMaxChunkSize) + ((srcSize % kMaxChunkSize) != 0);
+ size_t chunk;
+ size_t leftoverSize = 0;
+
+ assert(ZSTD_CHUNKSIZE_MAX >= kMaxChunkSize);
+ /* Check that ZSTD_window_update() has been called for this chunk prior
+ * to passing it to this function.
+ */
+ assert(ldmState->window.nextSrc >= (BYTE const*)src + srcSize);
+ /* The input could be very large (in zstdmt), so it must be broken up into
+ * chunks to enforce the maximum distance and handle overflow correction.
+ */
+ assert(sequences->pos <= sequences->size);
+ assert(sequences->size <= sequences->capacity);
+ for (chunk = 0; chunk < nbChunks && sequences->size < sequences->capacity; ++chunk) {
+ BYTE const* const chunkStart = istart + chunk * kMaxChunkSize;
+ size_t const remaining = (size_t)(iend - chunkStart);
+ BYTE const *const chunkEnd =
+ (remaining < kMaxChunkSize) ? iend : chunkStart + kMaxChunkSize;
+ size_t const chunkSize = chunkEnd - chunkStart;
+ size_t newLeftoverSize;
+ size_t const prevSize = sequences->size;
+
+ assert(chunkStart < iend);
+ /* 1. Perform overflow correction if necessary. */
+ if (ZSTD_window_needOverflowCorrection(ldmState->window, chunkEnd)) {
+ U32 const ldmHSize = 1U << params->hashLog;
+ U32 const correction = ZSTD_window_correctOverflow(
+ &ldmState->window, /* cycleLog */ 0, maxDist, chunkStart);
+ ZSTD_ldm_reduceTable(ldmState->hashTable, ldmHSize, correction);
+ /* invalidate dictionaries on overflow correction */
+ ldmState->loadedDictEnd = 0;
+ }
+ /* 2. We enforce the maximum offset allowed.
+ *
+ * kMaxChunkSize should be small enough that we don't lose too much of
+ * the window through early invalidation.
+ * TODO: * Test the chunk size.
+ * * Try invalidation after the sequence generation and test the
+ * the offset against maxDist directly.
+ *
+ * NOTE: Because of dictionaries + sequence splitting we MUST make sure
+ * that any offset used is valid at the END of the sequence, since it may
+ * be split into two sequences. This condition holds when using
+ * ZSTD_window_enforceMaxDist(), but if we move to checking offsets
+ * against maxDist directly, we'll have to carefully handle that case.
+ */
+ ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, &ldmState->loadedDictEnd, NULL);
+ /* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
+ newLeftoverSize = ZSTD_ldm_generateSequences_internal(
+ ldmState, sequences, params, chunkStart, chunkSize);
+ if (ZSTD_isError(newLeftoverSize))
+ return newLeftoverSize;
+ /* 4. We add the leftover literals from previous iterations to the first
+ * newly generated sequence, or add the `newLeftoverSize` if none are
+ * generated.
+ */
+ /* Prepend the leftover literals from the last call */
+ if (prevSize < sequences->size) {
+ sequences->seq[prevSize].litLength += (U32)leftoverSize;
+ leftoverSize = newLeftoverSize;
+ } else {
+ assert(newLeftoverSize == chunkSize);
+ leftoverSize += chunkSize;
+ }
+ }
+ return 0;
+}
+
+void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize, U32 const minMatch) {
+ while (srcSize > 0 && rawSeqStore->pos < rawSeqStore->size) {
+ rawSeq* seq = rawSeqStore->seq + rawSeqStore->pos;
+ if (srcSize <= seq->litLength) {
+ /* Skip past srcSize literals */
+ seq->litLength -= (U32)srcSize;
+ return;
+ }
+ srcSize -= seq->litLength;
+ seq->litLength = 0;
+ if (srcSize < seq->matchLength) {
+ /* Skip past the first srcSize of the match */
+ seq->matchLength -= (U32)srcSize;
+ if (seq->matchLength < minMatch) {
+ /* The match is too short, omit it */
+ if (rawSeqStore->pos + 1 < rawSeqStore->size) {
+ seq[1].litLength += seq[0].matchLength;
+ }
+ rawSeqStore->pos++;
+ }
+ return;
+ }
+ srcSize -= seq->matchLength;
+ seq->matchLength = 0;
+ rawSeqStore->pos++;
+ }
+}
+
+/**
+ * If the sequence length is longer than remaining then the sequence is split
+ * between this block and the next.
+ *
+ * Returns the current sequence to handle, or if the rest of the block should
+ * be literals, it returns a sequence with offset == 0.
+ */
+static rawSeq maybeSplitSequence(rawSeqStore_t* rawSeqStore,
+ U32 const remaining, U32 const minMatch)
+{
+ rawSeq sequence = rawSeqStore->seq[rawSeqStore->pos];
+ assert(sequence.offset > 0);
+ /* Likely: No partial sequence */
+ if (remaining >= sequence.litLength + sequence.matchLength) {
+ rawSeqStore->pos++;
+ return sequence;
+ }
+ /* Cut the sequence short (offset == 0 ==> rest is literals). */
+ if (remaining <= sequence.litLength) {
+ sequence.offset = 0;
+ } else if (remaining < sequence.litLength + sequence.matchLength) {
+ sequence.matchLength = remaining - sequence.litLength;
+ if (sequence.matchLength < minMatch) {
+ sequence.offset = 0;
+ }
+ }
+ /* Skip past `remaining` bytes for the future sequences. */
+ ZSTD_ldm_skipSequences(rawSeqStore, remaining, minMatch);
+ return sequence;
+}
+
+size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
+ ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+ void const* src, size_t srcSize)
+{
+ const ZSTD_compressionParameters* const cParams = &ms->cParams;
+ unsigned const minMatch = cParams->minMatch;
+ ZSTD_blockCompressor const blockCompressor =
+ ZSTD_selectBlockCompressor(cParams->strategy, ZSTD_matchState_dictMode(ms));
+ /* Input bounds */
+ BYTE const* const istart = (BYTE const*)src;
+ BYTE const* const iend = istart + srcSize;
+ /* Input positions */
+ BYTE const* ip = istart;
+
+ DEBUGLOG(5, "ZSTD_ldm_blockCompress: srcSize=%zu", srcSize);
+ assert(rawSeqStore->pos <= rawSeqStore->size);
+ assert(rawSeqStore->size <= rawSeqStore->capacity);
+ /* Loop through each sequence and apply the block compressor to the lits */
+ while (rawSeqStore->pos < rawSeqStore->size && ip < iend) {
+ /* maybeSplitSequence updates rawSeqStore->pos */
+ rawSeq const sequence = maybeSplitSequence(rawSeqStore,
+ (U32)(iend - ip), minMatch);
+ int i;
+ /* End signal */
+ if (sequence.offset == 0)
+ break;
+
+ assert(ip + sequence.litLength + sequence.matchLength <= iend);
+
+ /* Fill tables for block compressor */
+ ZSTD_ldm_limitTableUpdate(ms, ip);
+ ZSTD_ldm_fillFastTables(ms, ip);
+ /* Run the block compressor */
+ DEBUGLOG(5, "pos %u : calling block compressor on segment of size %u", (unsigned)(ip-istart), sequence.litLength);
+ {
+ size_t const newLitLength =
+ blockCompressor(ms, seqStore, rep, ip, sequence.litLength);
+ ip += sequence.litLength;
+ /* Update the repcodes */
+ for (i = ZSTD_REP_NUM - 1; i > 0; i--)
+ rep[i] = rep[i-1];
+ rep[0] = sequence.offset;
+ /* Store the sequence */
+ ZSTD_storeSeq(seqStore, newLitLength, ip - newLitLength, iend,
+ sequence.offset + ZSTD_REP_MOVE,
+ sequence.matchLength - MINMATCH);
+ ip += sequence.matchLength;
+ }
+ }
+ /* Fill the tables for the block compressor */
+ ZSTD_ldm_limitTableUpdate(ms, ip);
+ ZSTD_ldm_fillFastTables(ms, ip);
+ /* Compress the last literals */
+ return blockCompressor(ms, seqStore, rep, ip, iend - ip);
+}
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