}
}
-/*-*******************************
-* LDM helper functions
-*********************************/
+/*************************
+* LDM helper functions *
+*************************/
-/* ldm_moveForwardBytesInSeqStore():
+/* ZSTD_opt_skipBytesInLdmSeqStore():
* Moves forward in rawSeqStore by nbBytes, which will update the fields 'pos' and 'posInSequence'.
*/
-static void ldm_moveForwardBytesInSeqStore(rawSeqStore_t* ldmSeqStore, size_t nbBytes) {
+static void ZSTD_opt_skipBytesInLdmSeqStore(rawSeqStore_t* ldmSeqStore, size_t nbBytes) {
while (nbBytes && ldmSeqStore->pos < ldmSeqStore->size) {
- rawSeq currSeq;
- currSeq = ldmSeqStore->seq[ldmSeqStore->pos];
+ rawSeq currSeq = ldmSeqStore->seq[ldmSeqStore->pos];
+ assert(ldmSeqStore->posInSequence <= currSeq.matchLength + currSeq.litLength);
if (nbBytes <= currSeq.litLength) {
ldmSeqStore->posInSequence += nbBytes;
return;
}
}
-/* ldm_getNextMatchAndUpdateSeqStore():
+/* ZSTD_opt_getNextLdmAndUpdateSeqStore():
* Calculates the beginning and end of the next match in the current block.
* Updates 'pos' and 'posInSequence' of the ldmSeqStore.
*/
-static void ldm_getNextMatchAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore,
- U32* matchStartPosInBlock, U32* matchEndPosInBlock,
- U32* matchOffset, U32 currPosInBlock,
- U32 blockBytesRemaining) {
+static void ZSTD_opt_getNextLdmAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore,
+ U32* matchStartPosInBlock, U32* matchEndPosInBlock,
+ U32* matchOffset, U32 currPosInBlock,
+ U32 blockBytesRemaining) {
rawSeq currSeq;
U32 currBlockEndPos;
U32 literalsBytesRemaining;
*matchEndPosInBlock = UINT_MAX;
return;
}
-
/* Calculate appropriate bytes left in matchLength and litLength after adjusting
based on ldmSeqStore->posInSequence */
currSeq = ldmSeqStore->seq[ldmSeqStore->pos];
+ assert(ldmSeqStore->posInSequence <= currSeq.litLength + currSeq.matchLength);
currBlockEndPos = currPosInBlock + blockBytesRemaining;
literalsBytesRemaining = (ldmSeqStore->posInSequence < currSeq.litLength) ?
currSeq.litLength - ldmSeqStore->posInSequence :
if (literalsBytesRemaining >= blockBytesRemaining) {
*matchStartPosInBlock = UINT_MAX;
*matchEndPosInBlock = UINT_MAX;
- ldm_moveForwardBytesInSeqStore(ldmSeqStore, blockBytesRemaining);
+ ZSTD_opt_skipBytesInLdmSeqStore(ldmSeqStore, blockBytesRemaining);
return;
}
if (*matchEndPosInBlock > currBlockEndPos) {
/* Match ends after the block ends, we can't use the whole match */
*matchEndPosInBlock = currBlockEndPos;
- ldm_moveForwardBytesInSeqStore(ldmSeqStore, currBlockEndPos - currPosInBlock);
+ ZSTD_opt_skipBytesInLdmSeqStore(ldmSeqStore, currBlockEndPos - currPosInBlock);
} else {
/* If we can use the whole match point the ldmSeqStore at the next match */
ldmSeqStore->posInSequence = 0;
ldmSeqStore->pos++;
}
- DEBUGLOG(6, "ldm_getNextMatchAndUpdateSeqStore(): got an ldm that beginning at pos: %u, end at pos: %u, with offset: %u",
+ DEBUGLOG(6, "ZSTD_opt_getNextLdmAndUpdateSeqStore(): got an ldm that beginning at pos: %u, end at pos: %u, with offset: %u",
*matchStartPosInBlock, *matchEndPosInBlock, *matchOffset);
}
-/* ldm_maybeAddLdm():
+/* ZSTD_opt_maybeAddLdm():
* Adds a match if it's long enough, based on it's 'matchStartPosInBlock'
* and 'matchEndPosInBlock', into 'matches'. Maintains the correct ordering of 'matches'
*/
-static void ldm_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
- U32 matchStartPosInBlock, U32 matchEndPosInBlock,
- U32 matchOffset, U32 currPosInBlock) {
+static void ZSTD_opt_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
+ U32 matchStartPosInBlock, U32 matchEndPosInBlock,
+ U32 matchOffset, U32 currPosInBlock) {
U32 posDiff = currPosInBlock - matchStartPosInBlock;
/* Note: ZSTD_match_t actually contains offCode and matchLength (before subtracting MINMATCH) */
U32 candidateMatchLength = matchEndPosInBlock - matchStartPosInBlock - posDiff;
U32 candidateOffCode = matchOffset + posDiff + ZSTD_REP_MOVE;
/* Ensure that current block position is not outside of the match */
- if (currPosInBlock < matchStartPosInBlock ||
- currPosInBlock >= matchEndPosInBlock ||
- posDiff > 0 || /* As a next evolution we can enable adding LDMs in the middle of a match */
- candidateMatchLength < MINMATCH)
+ if (currPosInBlock < matchStartPosInBlock
+ || currPosInBlock >= matchEndPosInBlock
+ || posDiff > 0 /* As a next evolution we can enable adding LDMs in the middle of a match */
+ || candidateMatchLength < MINMATCH) {
return;
+ }
- DEBUGLOG(6, "ldm_maybeAddLdm(): Adding ldm candidate match (offCode: %u matchLength %u) at block position=%u",
+ DEBUGLOG(6, "ZSTD_opt_maybeAddLdm(): Adding ldm candidate match (offCode: %u matchLength %u) at block position=%u",
candidateOffCode, candidateMatchLength, currPosInBlock);
if (*nbMatches == 0) {
matches[*nbMatches].len = candidateMatchLength;
} else if ((candidateMatchLength >= matches[*nbMatches-1].len) && *nbMatches < ZSTD_OPT_NUM) {
/* Maintain order of matches, which is firstly - increasing in matchlength,
* and secondly - decreasing in offCode. Since matches from the ldm seq store are likely
- * to be the longest match found, we simply start at the end of the array and sift
+ * to be the longest match found, we simply start at the end of the array and bubble
* the ldm match down as necessary.
*/
if (candidateMatchLength == matches[*nbMatches-1].len) {
}
}
-/* Wrapper function to update and call ldm functions as necessary */
-static void ldm_handleLdm(rawSeqStore_t* ldmSeqStore, ZSTD_match_t* matches, U32* nbMatches,
- U32* matchStartPosInBlock, U32* matchEndPosInBlock, U32* matchOffset,
- U32 currPosInBlock, U32 remainingBytes) {
+/* ZSTD_opt_processLdm():
+ * Wrapper function to update ldm seq store and call ldm functions as necessary.
+ */
+static void ZSTD_opt_processLdm(rawSeqStore_t* ldmSeqStore, ZSTD_match_t* matches, U32* nbMatches,
+ U32* matchStartPosInBlock, U32* matchEndPosInBlock, U32* matchOffset,
+ U32 currPosInBlock, U32 remainingBytes) {
if (currPosInBlock >= *matchEndPosInBlock) {
if (currPosInBlock > *matchEndPosInBlock) {
- /* The position at which ldm_handleLdm() is called is not necessarily
+ /* The position at which ZSTD_opt_processLdm() is called is not necessarily
* at the end of a match from the ldm seq store, and will often be some bytes
* over beyond matchEndPosInBlock. As such, we need to correct for these "overshoots"
*/
U32 posOvershoot = currPosInBlock - *matchEndPosInBlock;
- ldm_moveForwardBytesInSeqStore(ldmSeqStore, posOvershoot);
+ ZSTD_opt_skipBytesInLdmSeqStore(ldmSeqStore, posOvershoot);
}
- ldm_getNextMatchAndUpdateSeqStore(ldmSeqStore, matchStartPosInBlock,
+ ZSTD_opt_getNextLdmAndUpdateSeqStore(ldmSeqStore, matchStartPosInBlock,
matchEndPosInBlock, matchOffset,
currPosInBlock, remainingBytes);
}
- ldm_maybeAddLdm(matches, nbMatches, *matchStartPosInBlock, *matchEndPosInBlock, *matchOffset, currPosInBlock);
+ ZSTD_opt_maybeAddLdm(matches, nbMatches, *matchStartPosInBlock, *matchEndPosInBlock, *matchOffset, currPosInBlock);
}
/* Get first match from ldm seq store if long mode is enabled */
if (ms->ldmSeqStore.size > 0 && ms->ldmSeqStore.pos < ms->ldmSeqStore.size) {
- ldm_getNextMatchAndUpdateSeqStore(&ms->ldmSeqStore, &ldmStartPosInBlock,
- &ldmEndPosInBlock, &ldmOffset,
- (U32)(ip-istart), (U32)(iend-ip));
+ ZSTD_opt_getNextLdmAndUpdateSeqStore(&ms->ldmSeqStore, &ldmStartPosInBlock,
+ &ldmEndPosInBlock, &ldmOffset,
+ (U32)(ip-istart), (U32)(iend-ip));
}
-
+
/* init */
DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u",
(U32)(ip - base), ms->window.dictLimit, ms->nextToUpdate);
U32 const ll0 = !litlen;
U32 nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch);
if (ms->ldmSeqStore.size != 0 && ms->ldmSeqStore.pos < ms->ldmSeqStore.size) {
- ldm_handleLdm(&ms->ldmSeqStore, matches,
- &nbMatches, &ldmStartPosInBlock,
- &ldmEndPosInBlock, &ldmOffset,
- (U32)(ip-istart), (U32)(iend - ip));
+ ZSTD_opt_processLdm(&ms->ldmSeqStore, matches,
+ &nbMatches, &ldmStartPosInBlock,
+ &ldmEndPosInBlock, &ldmOffset,
+ (U32)(ip-istart), (U32)(iend - ip));
}
if (!nbMatches) { ip++; continue; }
if (ms->ldmSeqStore.size != 0 && ms->ldmSeqStore.pos < ms->ldmSeqStore.size) {
- ldm_handleLdm(&ms->ldmSeqStore, matches,
- &nbMatches, &ldmStartPosInBlock,
- &ldmEndPosInBlock, &ldmOffset,
- (U32)(inr-istart), (U32)(iend-inr));
+ ZSTD_opt_processLdm(&ms->ldmSeqStore, matches,
+ &nbMatches, &ldmStartPosInBlock,
+ &ldmEndPosInBlock, &ldmOffset,
+ (U32)(inr-istart), (U32)(iend-inr));
}
if (!nbMatches) {
DEBUGLOG(7, "rPos:%u : no match found", cur);
if (ldmEndPosInBlock < srcSize) {
/* This can occur if after adding the final match in an ldm seq store within this block,
- ip reaches end of the block without calling ldm_getNextMatchAndUpdateSeqStore() */
- ldm_moveForwardBytesInSeqStore(&ms->ldmSeqStore, srcSize - ldmEndPosInBlock);
+ ip reaches end of the block without calling ZSTD_opt_getNextLdmAndUpdateSeqStore() */
+ ZSTD_opt_skipBytesInLdmSeqStore(&ms->ldmSeqStore, srcSize - ldmEndPosInBlock);
}
/* Return the last literals size */
return (size_t)(iend - anchor);
projects / thirdparty / zstd.git / commitdiff
