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This commit is contained in:
senhuang42 2020-09-29 16:35:06 -04:00
parent 78da2e1808
commit ea92fb3a68
5 changed files with 113 additions and 161 deletions
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2
lib/compress/zstd_compress.c
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@ -2336,7 +2336,7 @@ static size_t ZSTD_buildSeqStore(ZSTD_CCtx* zc, const void* src, size_t srcSize)
if (curr > ms->nextToUpdate + 384)
ms->nextToUpdate = curr - MIN(192, (U32)(curr - ms->nextToUpdate - 384));
}
//printf("--NEW BLOCK--\n");
/* select and store sequences */
{ ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
size_t lastLLSize;

2
lib/compress/zstd_compress_internal.h
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@ -94,7 +94,7 @@ typedef struct {
typedef struct {
rawSeq* seq; /* The start of the sequences */
BYTE const* base;
BYTE const* base; /* The match state window base when LDMs were generated */
size_t pos; /* The position where reading stopped. <= size. */
size_t size; /* The number of sequences. <= capacity. */
size_t capacity; /* The capacity starting from `seq` pointer */

17
lib/compress/zstd_ldm.c
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@ -562,13 +562,6 @@ static rawSeq maybeSplitSequence(rawSeqStore_t* rawSeqStore,
return sequence;
}
static void printSeqStore(rawSeqStore_t* rawSeqStore) {
printf("rawSeqStore: pos: %zu\n", rawSeqStore->pos);
for (int i = 0; i < rawSeqStore->size; ++i) {
printf("pos %d (of:%u ml:%u ll: %u)\n", i, rawSeqStore->seq[i].offset, rawSeqStore->seq[i].matchLength, rawSeqStore->seq[i].litLength);
}
}
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)
@ -582,19 +575,13 @@ size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
BYTE const* const iend = istart + srcSize;
/* Input positions */
BYTE const* ip = istart;
//printSeqStore(rawSeqStore);
if (cParams->strategy >= ZSTD_btopt) {
size_t lastLLSize;
//printSeqStore(rawSeqStore);
ms->ldmSeqStore = *rawSeqStore; /* copy current seqStore */
ms->ldmSeqStore = *rawSeqStore;
ms->ldmSeqStore.base = ms->window.base;
lastLLSize = blockCompressor(ms, seqStore, rep, src, srcSize);
/* ldm seqstore will have changed during blockCompressor() call, make sure we copy those changes */
*rawSeqStore = ms->ldmSeqStore;
/*if (prevBase != ms->window.base) {
int baseDiff = (int)(prevBase - ms->window.base);
printf("Bases were different, adjusting, diff = %d\n", baseDiff);
rawSeqStore->seq[rawSeqStore->pos].litLength += baseDiff;
}*/
return lastLLSize;
}

199
lib/compress/zstd_opt.c
View File

@ -765,90 +765,69 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
}
/*-*******************************
* LDM util functions
* LDM helper functions
*********************************/
static void ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize, U32 const minMatch) {
while (srcSize > 0 && rawSeqStore->pos < rawSeqStore->size) {
//////printf("ldm_skipSequences(): %u remaining\n", srcSize);
rawSeq* seq = rawSeqStore->seq + rawSeqStore->pos;
//////printf("ldm_skipSequences(): before: (of: %u, ml: %u, ll: %u)\n", seq->offset, seq->matchLength, seq->litLength);
if (srcSize <= seq->litLength) {
/* Skips past srcSize bytes in an ldm seqstore */
static void ldm_skipBytesInSeqStore(rawSeqStore_t* ldmSeqStore, size_t bytesToSkip) {
while (bytesToSkip > 0 && ldmSeqStore->pos < ldmSeqStore->size) {
rawSeq* seq = ldmSeqStore->seq + ldmSeqStore->pos;
if (bytesToSkip <= seq->litLength) {
/* Skip past srcSize literals */
seq->litLength -= (U32)srcSize;
//////printf("ldm_skipSequences(): seqstore final: (of: %u, ml: %u, ll: %u) at %u\n", seq->offset, seq->matchLength, seq->litLength, rawSeqStore->pos);
seq->litLength -= (U32)bytesToSkip;
return;
}
srcSize -= seq->litLength;
bytesToSkip -= seq->litLength;
seq->litLength = 0;
if (srcSize < seq->matchLength) {
//////printf("Splitting match: ml curr: %u ", seq->matchLength);
/* Skip past the first srcSize of the match */
seq->matchLength -= (U32)srcSize;
//////printf("ml in store left: %u ", seq->matchLength);
/*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++;
}*/
////printf("ldm_skipSequences(): seqstore final: (of: %u, ml: %u, ll: %u) at %u\n", seq->offset, seq->matchLength, seq->litLength, rawSeqStore->pos);
if (bytesToSkip < seq->matchLength) {
seq->matchLength -= (U32)bytesToSkip;
return;
}
srcSize -= seq->matchLength;
bytesToSkip -= seq->matchLength;
seq->matchLength = 0;
////printf("ldm_skipSequences(): seqstore final: (of: %u, ml: %u, ll: %u) at %u\n", seq->offset, seq->matchLength, seq->litLength, rawSeqStore->pos);
rawSeqStore->pos++;
ldmSeqStore->pos++;
}
}
// The only function that can update pos (i think, for now)
static rawSeq ldm_splitSequence(rawSeqStore_t* ldmSeqStore, U32* ldmSeqStoreBytesConsumed, U32 remainingBytes) {
/* Splits a sequence if it's across the boundary. May update pos in the seq store too
* Pretty much the same function as maybeSplitSequence() in zstd_ldm.c
*/
static rawSeq ldm_splitSequenceAndUpdateSeqStore(rawSeqStore_t* ldmSeqStore, U32 remainingBytes) {
rawSeq currSeq = ldmSeqStore->seq[ldmSeqStore->pos];
////printf("ldm_splitSequence(): Current sequence: (of: %u, ml: %u, ll: %u) - remaining: %u\n", currSeq.offset, currSeq.matchLength, currSeq.litLength, remainingBytes);
/* No split */
/* Case where don't split the match*/
if (remainingBytes >= currSeq.litLength + currSeq.matchLength) {
//////printf("NO SPLIT\n");
*ldmSeqStoreBytesConsumed += currSeq.litLength + currSeq.matchLength;
ldmSeqStore->pos++;
//////printf("pos is now: %u\n", ldmSeqStore->pos);
return currSeq;
}
/* Need a split */
if (remainingBytes <= currSeq.litLength) {
//////printf("SPLITTING: all remaining bytes were literals");
currSeq.offset = 0;
} else if (remainingBytes < currSeq.litLength + currSeq.matchLength) {
/*if (currSeq.matchLength < MINMATCH) {
//////printf("CurrSeq less than minmatch: all remaining bytes were literals");
currSeq.offset = 0;
}*/
currSeq.matchLength = remainingBytes - currSeq.litLength;
}
//////printf("\n");
*ldmSeqStoreBytesConsumed += remainingBytes;
ldm_skipSequences(ldmSeqStore, remainingBytes, MINMATCH);
////printf("ldm_splitSequence(): Sequence final: (of: %u, ml: %u, ll: %u)\n", currSeq.offset, currSeq.matchLength, currSeq.litLength);
/* After deriving currSeq which is the sequence before the block boundary,
* we now must skip past the remaining number of bytes unaccounted for,
* and update the entry at pos in the seqStore, which represents the second half
* of the sequence after the block boundary
*/
ldm_skipBytesInSeqStore(ldmSeqStore, remainingBytes);
return currSeq;
}
/* Returns 1 if the rest of the block is just LDM literals */
static int ldm_getNextMatch(rawSeqStore_t* ldmSeqStore, U32* ldmSeqStoreBytesConsumed,
/* Fetch the next match in the ldm seq store */
static void ldm_getNextMatch(rawSeqStore_t* ldmSeqStore,
U32* matchStartPosInBlock, U32* matchEndPosInBlock,
U32* matchOffset, U32 currPosInBlock,
U32 remainingBytes, U32 sbi) {
U32 remainingBytes) {
/* Setting match end position to MAX will ensure we never use an LDM during this block */
if (ldmSeqStore->pos >= ldmSeqStore->size) {
// Don't use the LDM for the rest of the block (there is none)
////printf("No ldm left in the block, pos max reached\n");
*matchStartPosInBlock = UINT32_MAX;
*matchEndPosInBlock = UINT32_MAX;
return 1;
}
rawSeq seq = ldm_splitSequence(ldmSeqStore, ldmSeqStoreBytesConsumed, remainingBytes);
rawSeq seq = ldm_splitSequenceAndUpdateSeqStore(ldmSeqStore, remainingBytes);
if (seq.offset == 0) {
// Don't use the LDM for the rest of the block (there is none)
//////printf("No ldm left in the block, offset = 0\n");
*matchStartPosInBlock = UINT32_MAX;
*matchEndPosInBlock = UINT32_MAX;
return 1;
@ -857,70 +836,46 @@ static int ldm_getNextMatch(rawSeqStore_t* ldmSeqStore, U32* ldmSeqStoreBytesCon
*matchStartPosInBlock = currPosInBlock + seq.litLength;
*matchEndPosInBlock = *matchStartPosInBlock + seq.matchLength;
*matchOffset = seq.offset;
////printf("New match range in block is: (%u, %u) with of: %u where currPosInBlock: %u at adjusted absolute range: %u, %u\n", *matchStartPosInBlock, *matchEndPosInBlock, *matchOffset, currPosInBlock, *matchStartPosInBlock+sbi, *matchEndPosInBlock+sbi);
return 0;
}
static void printMatches(ZSTD_match_t* matches, U32 nbMatches) {
for (int i = 0; i < nbMatches; ++i) {
//printf("(of: %u ml: %u) ", matches[i].off, matches[i].len);
}
//printf("\n");
}
static void validateMatches(ZSTD_match_t* matches, U32 nbMatches) {
U32 prevLargestOffset = 0;
U32 prevLargestMatch = 0;
for (int i = 1; i < nbMatches; ++i) {
if (matches[i-1].len > matches[i].len) {
//printf("nope\n");
exit(1);
} else if (matches[i-1].len == matches[i].len) {
if (matches[i-1].off < matches[i].off) {
//printf("nopeOff\n");
exit(1);
}
}
}
}
/* Adds an LDM if it's long enough */
static void ldm_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
U32 matchStartPosInBlock, U32 matchEndPosInBlock,
U32 matchOffset, U32 currPosInBlock, U32 curr, U32 sbi, rawSeqStore_t* rawSeqStore) {
U32 matchOffset, U32 currPosInBlock) {
/* Check that current block position is not outside of the match */
if (currPosInBlock < matchStartPosInBlock || currPosInBlock >= matchEndPosInBlock)
return;
U32 posDiff = currPosInBlock - matchStartPosInBlock;
/* TODO: Next step will enable adding LDMs in the middle of a match */
if (posDiff > 0)
return; // dont deal with extra ldms for now
assert(posDiff < matchEndPosInBlock - matchStartPosInBlock);
return;
/* Note: ZSTD_match_t actually contains offCode and matchLength (before subtracting MINMATCH) */
U32 candidateMatchLength = matchEndPosInBlock - matchStartPosInBlock - posDiff;
if (candidateMatchLength < ZSTD_LDM_MINMATCH_MIN)
return;
U32 candidateOffCode = matchOffset + posDiff + ZSTD_REP_MOVE;
if ((*nbMatches == 0 || candidateMatchLength >= matches[*nbMatches-1].len) && *nbMatches < ZSTD_OPT_NUM) {
//printf("large enough: curr: %u currposinblock: %u (ofcode: %u, ml: %u) - range: (%u, %u) - (of: %u ml: %u ll: %u) @ pos: %u - \n",
// curr, currPosInBlock, candidateOffCode, candidateMatchLength, matchStartPosInBlock, matchEndPosInBlock, rawSeqStore->seq[rawSeqStore->pos].offset, rawSeqStore->seq[rawSeqStore->pos].matchLength, rawSeqStore->seq[rawSeqStore->pos].litLength, rawSeqStore->pos);
if (*nbMatches == 0) {
//printf("HERE1\n");
matches[*nbMatches].len = candidateMatchLength;
matches[*nbMatches].off = candidateOffCode;
(*nbMatches)++;
} else {
} else if ((candidateMatchLength >= matches[*nbMatches-1].len) && *nbMatches < ZSTD_OPT_NUM) {
/* Maintain order of matches, which is first - increasing in matchlength,
* and secondly - decreasing in offCode. Since matches in ldm seq store are likely
* to be the longest match found, we simply start at the end of the array and sift
* the ldm match down as necessary.
*/
if (candidateMatchLength == matches[*nbMatches-1].len) {
//printf("HERE2\n");
U32 candidateMatchIdx = *nbMatches;
matches[*nbMatches].len = candidateMatchLength;
matches[*nbMatches].off = candidateOffCode;
if (candidateOffCode != matches[*nbMatches-1].off) {
//printf("offsets not equal\n");
while (candidateMatchIdx > 0 &&
matches[candidateMatchIdx].off > matches[candidateMatchIdx - 1].off &&
matches[candidateMatchIdx].len == matches[candidateMatchIdx - 1].len) {
//printf("sifting\n");
ZSTD_match_t tmp = matches[candidateMatchIdx - 1];
matches[candidateMatchIdx - 1] = matches[candidateMatchIdx];
matches[candidateMatchIdx] = tmp;
@ -929,34 +884,31 @@ static void ldm_maybeAddLdm(ZSTD_match_t* matches, U32* nbMatches,
}
(*nbMatches)++;
} else {
//printf("HERE3\n");
matches[*nbMatches].len = candidateMatchLength;
matches[*nbMatches].off = candidateOffCode;
(*nbMatches)++;
}
}
printMatches(matches, *nbMatches);
validateMatches(matches, *nbMatches);
}
}
/* Wrapper function to call ldm functions as needed */
static void ldm_handleLdm(rawSeqStore_t* ldmSeqStore, U32* ldmSeqStoreBytesConsumed, 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, U32 curr, U32 sbi) {
//////printf("currPosInBlock: %u, curr: %u, called ldm_handleLdm()", currPosInBlock, curr);
U32 currPosInBlock, U32 remainingBytes) {
if (currPosInBlock >= *matchEndPosInBlock) {
////printf("Went over match boundary: currPosInBlock: %u, %matchEndPosInBlock: %u\n", currPosInBlock, *matchEndPosInBlock);
if (currPosInBlock > *matchEndPosInBlock) {
/* The position at which ldm_handleLdm() is called is not necessarily
* at the end of a match from the ldm seq store, and will often be some bytes
* over the end of an ldm match. As such, we need to correct for these "overshoots"
*/
U32 posOvershoot = currPosInBlock - *matchEndPosInBlock;
////printf("Overshot position by: %u\n", posOvershoot);
ldm_skipSequences(ldmSeqStore, posOvershoot, MINMATCH);
ldm_skipBytesInSeqStore(ldmSeqStore, posOvershoot);
}
int noMoreLdms = ldm_getNextMatch(ldmSeqStore, ldmSeqStoreBytesConsumed, matchStartPosInBlock,
ldm_getNextMatch(ldmSeqStore, matchStartPosInBlock,
matchEndPosInBlock, matchOffset,
currPosInBlock, remainingBytes, sbi);
currPosInBlock, remainingBytes);
}
ldm_maybeAddLdm(matches, nbMatches, *matchStartPosInBlock, *matchEndPosInBlock, *matchOffset, currPosInBlock, curr, sbi, ldmSeqStore);
ldm_maybeAddLdm(matches, nbMatches, *matchStartPosInBlock, *matchEndPosInBlock, *matchOffset, currPosInBlock);
}
@ -1008,7 +960,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4;
U32 nextToUpdate3 = ms->nextToUpdate;
U32 const sbi = (U32)(istart-base);
ZSTD_optimal_t* const opt = optStatePtr->priceTable;
ZSTD_match_t* const matches = optStatePtr->matchTable;
@ -1017,18 +968,34 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
U32 ldmStartPosInBlock = 0;
U32 ldmEndPosInBlock = 0;
U32 ldmOffset = 0;
U32 ldmSeqStoreBytesConsumed = 0;
//////printf("SBI for this block: %u, base: %u\n", sbi, base);
if (ms->ldmSeqStore.size > 0 && ms->ldmSeqStore.base != base) {
/* It seems that if the ldm seqstore was calculated using a different base, we actually have to
* apply a correction to line it up with the block itself. This applies to multi-threaded cases
* where the block it can be the case that the LDMs were generated starting at a different
* block. By adding baseDiff to the litLength of seq, we pad out that base difference.
*
* For example, I found that when compressing dickens from silesia, the first LDM according to the seqStore is:
* (of:951277 ml:1362 ll: 952876)
*
* And as such, we might expect to insert the match in the 7th block at:
* pos_in_block 35373 == 952877 - 131072 * 7
* I.e., at position 35373 the 7th block.
*
* Surprisingly, the correct place to insert is in the 8th block at
* pos_in_block 35373 = 1083948 - 131072 * 8
*
* since the base shifts back 131072 bytes (1 block) after the first block. The consequence is that
* we should insert 35373 bytes into the 8th block, rather than 35373 bytes into the 7th block.
*/
if (ms->ldmSeqStore.size > 0) {
if (ms->ldmSeqStore.base != base) {
int baseDiff = (int)(ms->ldmSeqStore.base - base);
////printf("Bases were different, adjusting, diff = %d\n", baseDiff);
ms->ldmSeqStore.seq[ms->ldmSeqStore.pos].litLength += baseDiff;
ms->ldmSeqStore.base = ms->window.base;
}
if (ms->ldmSeqStore.size != 0) {
ldm_getNextMatch(&ms->ldmSeqStore, &ldmSeqStoreBytesConsumed, &ldmStartPosInBlock,
&ldmEndPosInBlock, &ldmOffset, (U32)(ip-istart), (U32)(iend-ip), sbi);
ldm_getNextMatch(&ms->ldmSeqStore, &ldmStartPosInBlock,
&ldmEndPosInBlock, &ldmOffset,
(U32)(ip-istart), (U32)(iend-ip));
}
/* init */
DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u",
@ -1046,10 +1013,10 @@ 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) {
ldm_handleLdm(&ms->ldmSeqStore, &ldmSeqStoreBytesConsumed, matches,
ldm_handleLdm(&ms->ldmSeqStore, matches,
&nbMatches, &ldmStartPosInBlock,
&ldmEndPosInBlock, &ldmOffset,
(U32)(ip-istart), (U32)(iend - ip), (U32)(ip-base), sbi);
(U32)(ip-istart), (U32)(iend - ip));
}
if (!nbMatches) { ip++; continue; }
@ -1168,10 +1135,10 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
if (ms->ldmSeqStore.size != 0) {
ldm_handleLdm(&ms->ldmSeqStore, &ldmSeqStoreBytesConsumed, matches,
ldm_handleLdm(&ms->ldmSeqStore, matches,
&nbMatches, &ldmStartPosInBlock,
&ldmEndPosInBlock, &ldmOffset,
(U32)(inr-istart), (U32)(iend-inr), (U32)(inr-base), sbi);
(U32)(inr-istart), (U32)(iend-inr));
}
if (!nbMatches) {
DEBUGLOG(7, "rPos:%u : no match found", cur);
@ -1287,12 +1254,10 @@ _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
}
} /* while (ip < ilimit) */
int i = ms->ldmSeqStore.pos;
////printf("pos %d (of:%u ml:%u ll: %u)\n", i, ms->ldmSeqStore.seq[i].offset, ms->ldmSeqStore.seq[i].matchLength, ms->ldmSeqStore.seq[i].litLength);
////printf("matchend: %u bytesconsumed: %u\n", ldmEndPosInBlock, ldmSeqStoreBytesConsumed);
if (ldmEndPosInBlock < srcSize) {
////printf("Needs adjustment, endpos didn't reach end of block\n");
ldm_skipSequences(&ms->ldmSeqStore, srcSize - ldmEndPosInBlock, MINMATCH);
/* This can occur if after adding the final match in an ldm seq store within this block,
ip goes to the end of the block without activating a check for ldm_getNextMatch */
ldm_skipBytesInSeqStore(&ms->ldmSeqStore, srcSize - ldmEndPosInBlock);
}
/* Return the last literals size */
return (size_t)(iend - anchor);

2
lib/compress/zstdmt_compress.c
View File

@ -266,7 +266,7 @@ static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buf)
/* ===== Seq Pool Wrapper ====== */
static rawSeqStore_t kNullRawSeqStore = {NULL, 0, 0, 0};
static rawSeqStore_t kNullRawSeqStore = {NULL, NULL, 0, 0, 0};
typedef ZSTDMT_bufferPool ZSTDMT_seqPool;