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Prefix new static ldm helpers with ZSTD_opt

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This commit is contained in:
senhuang42 2020-10-01 16:14:41 -04:00
parent 429dec4f42
commit c87d2e5866
1 changed files with 51 additions and 48 deletions
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99
lib/compress/zstd_opt.c
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@ -764,17 +764,17 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
}
}
/*-*******************************
* 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;
@ -795,14 +795,14 @@ static void ldm_moveForwardBytesInSeqStore(rawSeqStore_t* ldmSeqStore, size_t nb
}
}
/* 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;
@ -814,10 +814,10 @@ static void ldm_getNextMatchAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore,
*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 :
@ -830,7 +830,7 @@ static void ldm_getNextMatchAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore,
if (literalsBytesRemaining >= blockBytesRemaining) {
*matchStartPosInBlock = UINT_MAX;
*matchEndPosInBlock = UINT_MAX;
ldm_moveForwardBytesInSeqStore(ldmSeqStore, blockBytesRemaining);
ZSTD_opt_skipBytesInLdmSeqStore(ldmSeqStore, blockBytesRemaining);
return;
}
@ -843,36 +843,37 @@ static void ldm_getNextMatchAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore,
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;
@ -881,7 +882,7 @@ static void ldm_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
} 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) {
@ -912,24 +913,26 @@ static void ldm_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
}
}
/* 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);
}
@ -992,11 +995,11 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
/* 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);
@ -1013,10 +1016,10 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
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; }
@ -1135,10 +1138,10 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
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);
@ -1256,8 +1259,8 @@ _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
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);