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Merge pull request #2387 from senhuang42/compress_sequence_API

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[RFC] New sequence compression API
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sen 2020-11-20 16:54:20 -05:00 committed by GitHub
commit c5fbd55dac
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4 changed files with 657 additions and 86 deletions
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601
lib/compress/zstd_compress.c
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@ -457,6 +457,16 @@ ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter param)
bounds.lowerBound = (int)ZSTD_bm_buffered;
bounds.upperBound = (int)ZSTD_bm_stable;
return bounds;
case ZSTD_c_blockDelimiters:
bounds.lowerBound = (int)ZSTD_sf_noBlockDelimiters;
bounds.upperBound = (int)ZSTD_sf_explicitBlockDelimiters;
return bounds;
case ZSTD_c_validateSequences:
bounds.lowerBound = 0;
bounds.upperBound = 1;
return bounds;
default:
bounds.error = ERROR(parameter_unsupported);
@ -517,6 +527,8 @@ static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
case ZSTD_c_srcSizeHint:
case ZSTD_c_stableInBuffer:
case ZSTD_c_stableOutBuffer:
case ZSTD_c_blockDelimiters:
case ZSTD_c_validateSequences:
default:
return 0;
}
@ -567,6 +579,8 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value)
case ZSTD_c_srcSizeHint:
case ZSTD_c_stableInBuffer:
case ZSTD_c_stableOutBuffer:
case ZSTD_c_blockDelimiters:
case ZSTD_c_validateSequences:
break;
default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
@ -767,6 +781,16 @@ size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* CCtxParams,
BOUNDCHECK(ZSTD_c_stableOutBuffer, value);
CCtxParams->outBufferMode = (ZSTD_bufferMode_e)value;
return CCtxParams->outBufferMode;
case ZSTD_c_blockDelimiters:
BOUNDCHECK(ZSTD_c_blockDelimiters, value);
CCtxParams->blockDelimiters = (ZSTD_sequenceFormat_e)value;
return CCtxParams->blockDelimiters;
case ZSTD_c_validateSequences:
BOUNDCHECK(ZSTD_c_validateSequences, value);
CCtxParams->validateSequences = value;
return CCtxParams->validateSequences;
default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
}
@ -885,6 +909,12 @@ size_t ZSTD_CCtxParams_getParameter(
case ZSTD_c_stableOutBuffer :
*value = (int)CCtxParams->outBufferMode;
break;
case ZSTD_c_blockDelimiters :
*value = (int)CCtxParams->blockDelimiters;
break;
case ZSTD_c_validateSequences :
*value = (int)CCtxParams->validateSequences;
break;
default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
}
return 0;
@ -2114,10 +2144,10 @@ static int ZSTD_useTargetCBlockSize(const ZSTD_CCtx_params* cctxParams)
return (cctxParams->targetCBlockSize != 0);
}
/* ZSTD_compressSequences_internal():
/* ZSTD_entropyCompressSequences_internal():
* actually compresses both literals and sequences */
MEM_STATIC size_t
ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
ZSTD_entropyCompressSequences_internal(seqStore_t* seqStorePtr,
const ZSTD_entropyCTables_t* prevEntropy,
ZSTD_entropyCTables_t* nextEntropy,
const ZSTD_CCtx_params* cctxParams,
@ -2146,7 +2176,7 @@ ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
entropyWorkspace = count + (MaxSeq + 1);
entropyWkspSize -= (MaxSeq + 1) * sizeof(*count);
DEBUGLOG(5, "ZSTD_compressSequences_internal (nbSeq=%zu)", nbSeq);
DEBUGLOG(4, "ZSTD_entropyCompressSequences_internal (nbSeq=%zu)", nbSeq);
ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
assert(entropyWkspSize >= HUF_WORKSPACE_SIZE);
@ -2308,7 +2338,7 @@ ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
}
MEM_STATIC size_t
ZSTD_compressSequences(seqStore_t* seqStorePtr,
ZSTD_entropyCompressSequences(seqStore_t* seqStorePtr,
const ZSTD_entropyCTables_t* prevEntropy,
ZSTD_entropyCTables_t* nextEntropy,
const ZSTD_CCtx_params* cctxParams,
@ -2317,7 +2347,7 @@ ZSTD_compressSequences(seqStore_t* seqStorePtr,
void* entropyWorkspace, size_t entropyWkspSize,
int bmi2)
{
size_t const cSize = ZSTD_compressSequences_internal(
size_t const cSize = ZSTD_entropyCompressSequences_internal(
seqStorePtr, prevEntropy, nextEntropy, cctxParams,
dst, dstCapacity,
entropyWorkspace, entropyWkspSize, bmi2);
@ -2327,13 +2357,13 @@ ZSTD_compressSequences(seqStore_t* seqStorePtr,
*/
if ((cSize == ERROR(dstSize_tooSmall)) & (srcSize <= dstCapacity))
return 0; /* block not compressed */
FORWARD_IF_ERROR(cSize, "ZSTD_compressSequences_internal failed");
FORWARD_IF_ERROR(cSize, "ZSTD_entropyCompressSequences_internal failed");
/* Check compressibility */
{ size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, cctxParams->cParams.strategy);
if (cSize >= maxCSize) return 0; /* block not compressed */
}
DEBUGLOG(4, "ZSTD_entropyCompressSequences() cSize: %zu\n", cSize);
return cSize;
}
@ -2658,7 +2688,7 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
}
/* encode sequences and literals */
cSize = ZSTD_compressSequences(&zc->seqStore,
cSize = ZSTD_entropyCompressSequences(&zc->seqStore,
&zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
&zc->appliedParams,
dst, dstCapacity,
@ -2666,6 +2696,12 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
zc->bmi2);
if (zc->seqCollector.collectSequences) {
ZSTD_copyBlockSequences(zc);
return 0;
}
if (frame &&
/* We don't want to emit our first block as a RLE even if it qualifies because
* doing so will cause the decoder (cli only) to throw a "should consume all input error."
@ -2813,7 +2849,7 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
assert(cctx->appliedParams.cParams.windowLog <= ZSTD_WINDOWLOG_MAX);
DEBUGLOG(5, "ZSTD_compress_frameChunk (blockSize=%u)", (unsigned)blockSize);
DEBUGLOG(4, "ZSTD_compress_frameChunk (blockSize=%u)", (unsigned)blockSize);
if (cctx->appliedParams.fParams.checksumFlag && srcSize)
XXH64_update(&cctx->xxhState, src, srcSize);
@ -2893,7 +2929,6 @@ static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
"dst buf is too small to fit worst-case frame header size.");
DEBUGLOG(4, "ZSTD_writeFrameHeader : dictIDFlag : %u ; dictID : %u ; dictIDSizeCode : %u",
!params->fParams.noDictIDFlag, (unsigned)dictID, (unsigned)dictIDSizeCode);
if (params->format == ZSTD_f_zstd1) {
MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
pos = 4;
@ -3461,7 +3496,6 @@ size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
return cSize + endResult;
}
static size_t ZSTD_compress_internal (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
@ -4309,6 +4343,81 @@ static size_t ZSTD_checkBufferStability(ZSTD_CCtx const* cctx,
return 0;
}
static size_t ZSTD_CCtx_init_compressStream2(ZSTD_CCtx* cctx,
ZSTD_EndDirective endOp,
size_t inSize) {
ZSTD_CCtx_params params = cctx->requestedParams;
ZSTD_prefixDict const prefixDict = cctx->prefixDict;
FORWARD_IF_ERROR( ZSTD_initLocalDict(cctx) , ""); /* Init the local dict if present. */
ZSTD_memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict)); /* single usage */
assert(prefixDict.dict==NULL || cctx->cdict==NULL); /* only one can be set */
if (cctx->cdict)
params.compressionLevel = cctx->cdict->compressionLevel; /* let cdict take priority in terms of compression level */
DEBUGLOG(4, "ZSTD_compressStream2 : transparent init stage");
if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = inSize + 1; /* auto-fix pledgedSrcSize */
{
size_t const dictSize = prefixDict.dict
? prefixDict.dictSize
: (cctx->cdict ? cctx->cdict->dictContentSize : 0);
ZSTD_cParamMode_e const mode = ZSTD_getCParamMode(cctx->cdict, &params, cctx->pledgedSrcSizePlusOne - 1);
params.cParams = ZSTD_getCParamsFromCCtxParams(
&params, cctx->pledgedSrcSizePlusOne-1,
dictSize, mode);
}
if (ZSTD_CParams_shouldEnableLdm(&params.cParams)) {
/* Enable LDM by default for optimal parser and window size >= 128MB */
DEBUGLOG(4, "LDM enabled by default (window size >= 128MB, strategy >= btopt)");
params.ldmParams.enableLdm = 1;
}
#ifdef ZSTD_MULTITHREAD
if ((cctx->pledgedSrcSizePlusOne-1) <= ZSTDMT_JOBSIZE_MIN) {
params.nbWorkers = 0; /* do not invoke multi-threading when src size is too small */
}
if (params.nbWorkers > 0) {
/* mt context creation */
if (cctx->mtctx == NULL) {
DEBUGLOG(4, "ZSTD_compressStream2: creating new mtctx for nbWorkers=%u",
params.nbWorkers);
cctx->mtctx = ZSTDMT_createCCtx_advanced((U32)params.nbWorkers, cctx->customMem, cctx->pool);
RETURN_ERROR_IF(cctx->mtctx == NULL, memory_allocation, "NULL pointer!");
}
/* mt compression */
DEBUGLOG(4, "call ZSTDMT_initCStream_internal as nbWorkers=%u", params.nbWorkers);
FORWARD_IF_ERROR( ZSTDMT_initCStream_internal(
cctx->mtctx,
prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType,
cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) , "");
cctx->streamStage = zcss_load;
cctx->appliedParams = params;
} else
#endif
{ U64 const pledgedSrcSize = cctx->pledgedSrcSizePlusOne - 1;
assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType, ZSTD_dtlm_fast,
cctx->cdict,
&params, pledgedSrcSize,
ZSTDb_buffered) , "");
assert(cctx->appliedParams.nbWorkers == 0);
cctx->inToCompress = 0;
cctx->inBuffPos = 0;
if (cctx->appliedParams.inBufferMode == ZSTD_bm_buffered) {
/* for small input: avoid automatic flush on reaching end of block, since
* it would require to add a 3-bytes null block to end frame
*/
cctx->inBuffTarget = cctx->blockSize + (cctx->blockSize == pledgedSrcSize);
} else {
cctx->inBuffTarget = 0;
}
cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
cctx->streamStage = zcss_load;
cctx->frameEnded = 0;
}
return 0;
}
size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
ZSTD_outBuffer* output,
ZSTD_inBuffer* input,
@ -4323,77 +4432,8 @@ size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
/* transparent initialization stage */
if (cctx->streamStage == zcss_init) {
ZSTD_CCtx_params params = cctx->requestedParams;
ZSTD_prefixDict const prefixDict = cctx->prefixDict;
FORWARD_IF_ERROR( ZSTD_initLocalDict(cctx) , ""); /* Init the local dict if present. */
ZSTD_memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict)); /* single usage */
assert(prefixDict.dict==NULL || cctx->cdict==NULL); /* only one can be set */
if (cctx->cdict)
params.compressionLevel = cctx->cdict->compressionLevel; /* let cdict take priority in terms of compression level */
DEBUGLOG(4, "ZSTD_compressStream2 : transparent init stage");
if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = input->size + 1; /* auto-fix pledgedSrcSize */
{
size_t const dictSize = prefixDict.dict
? prefixDict.dictSize
: (cctx->cdict ? cctx->cdict->dictContentSize : 0);
ZSTD_cParamMode_e const mode = ZSTD_getCParamMode(cctx->cdict, &params, cctx->pledgedSrcSizePlusOne - 1);
params.cParams = ZSTD_getCParamsFromCCtxParams(
&params, cctx->pledgedSrcSizePlusOne-1,
dictSize, mode);
}
if (ZSTD_CParams_shouldEnableLdm(&params.cParams)) {
/* Enable LDM by default for optimal parser and window size >= 128MB */
DEBUGLOG(4, "LDM enabled by default (window size >= 128MB, strategy >= btopt)");
params.ldmParams.enableLdm = 1;
}
#ifdef ZSTD_MULTITHREAD
if ((cctx->pledgedSrcSizePlusOne-1) <= ZSTDMT_JOBSIZE_MIN) {
params.nbWorkers = 0; /* do not invoke multi-threading when src size is too small */
}
if (params.nbWorkers > 0) {
/* mt context creation */
if (cctx->mtctx == NULL) {
DEBUGLOG(4, "ZSTD_compressStream2: creating new mtctx for nbWorkers=%u",
params.nbWorkers);
cctx->mtctx = ZSTDMT_createCCtx_advanced((U32)params.nbWorkers, cctx->customMem, cctx->pool);
RETURN_ERROR_IF(cctx->mtctx == NULL, memory_allocation, "NULL pointer!");
}
/* mt compression */
DEBUGLOG(4, "call ZSTDMT_initCStream_internal as nbWorkers=%u", params.nbWorkers);
FORWARD_IF_ERROR( ZSTDMT_initCStream_internal(
cctx->mtctx,
prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType,
cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) , "");
cctx->streamStage = zcss_load;
cctx->appliedParams = params;
} else
#endif
{ U64 const pledgedSrcSize = cctx->pledgedSrcSizePlusOne - 1;
assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType, ZSTD_dtlm_fast,
cctx->cdict,
&params, pledgedSrcSize,
ZSTDb_buffered) , "");
assert(cctx->appliedParams.nbWorkers == 0);
cctx->inToCompress = 0;
cctx->inBuffPos = 0;
if (cctx->appliedParams.inBufferMode == ZSTD_bm_buffered) {
/* for small input: avoid automatic flush on reaching end of block, since
* it would require to add a 3-bytes null block to end frame
*/
cctx->inBuffTarget = cctx->blockSize + (cctx->blockSize == pledgedSrcSize);
} else {
cctx->inBuffTarget = 0;
}
cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
cctx->streamStage = zcss_load;
cctx->frameEnded = 0;
}
/* Set initial buffer expectations now that we've initialized */
ZSTD_setBufferExpectations(cctx, output, input);
FORWARD_IF_ERROR(ZSTD_CCtx_init_compressStream2(cctx, endOp, input->size), "CompressStream2 initialization failed");
ZSTD_setBufferExpectations(cctx, output, input); /* Set initial buffer expectations now that we've initialized */
}
/* end of transparent initialization stage */
@ -4476,6 +4516,403 @@ size_t ZSTD_compress2(ZSTD_CCtx* cctx,
}
}
typedef struct {
U32 idx; /* Index in array of ZSTD_Sequence */
U32 posInSequence; /* Position within sequence at idx */
size_t posInSrc; /* Number of bytes given by sequences provided so far */
} ZSTD_sequencePosition;
/* Returns a ZSTD error code if sequence is not valid */
static size_t ZSTD_validateSequence(U32 offCode, U32 matchLength,
size_t posInSrc, U32 windowLog, size_t dictSize) {
size_t offsetBound;
U32 windowSize = 1 << windowLog;
/* posInSrc represents the amount of data the the decoder would decode up to this point.
* As long as the amount of data decoded is less than or equal to window size, offsets may be
* larger than the total length of output decoded in order to reference the dict, even larger than
* window size. After output surpasses windowSize, we're limited to windowSize offsets again.
*/
offsetBound = posInSrc > windowSize ? (size_t)windowSize : posInSrc + (size_t)dictSize;
RETURN_ERROR_IF(offCode > offsetBound + ZSTD_REP_MOVE, corruption_detected, "Offset too large!");
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small");
return 0;
}
/* Returns an offset code, given a sequence's raw offset, the ongoing repcode array, and whether litLength == 0 */
static U32 ZSTD_finalizeOffCode(U32 rawOffset, const U32 rep[ZSTD_REP_NUM], U32 ll0) {
U32 offCode = rawOffset + ZSTD_REP_MOVE;
U32 repCode = 0;
if (!ll0 && rawOffset == rep[0]) {
repCode = 1;
} else if (rawOffset == rep[1]) {
repCode = 2 - ll0;
} else if (rawOffset == rep[2]) {
repCode = 3 - ll0;
} else if (ll0 && rawOffset == rep[0] - 1) {
repCode = 3;
}
if (repCode) {
/* ZSTD_storeSeq expects a number in the range [0, 2] to represent a repcode */
offCode = repCode - 1;
}
return offCode;
}
/* Returns 0 on success, and a ZSTD_error otherwise. This function scans through an array of
* ZSTD_Sequence, storing the sequences it finds, until it reaches a block delimiter.
*/
static size_t ZSTD_copySequencesToSeqStoreExplicitBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition* seqPos,
const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
const void* src, size_t blockSize) {
U32 idx = seqPos->idx;
BYTE const* ip = (BYTE const*)(src);
const BYTE* const iend = ip + blockSize;
repcodes_t updatedRepcodes;
U32 dictSize;
U32 litLength;
U32 matchLength;
U32 ll0;
U32 offCode;
if (cctx->cdict) {
dictSize = (U32)cctx->cdict->dictContentSize;
} else if (cctx->prefixDict.dict) {
dictSize = (U32)cctx->prefixDict.dictSize;
} else {
dictSize = 0;
}
ZSTD_memcpy(updatedRepcodes.rep, cctx->blockState.prevCBlock->rep, sizeof(repcodes_t));
for (; (inSeqs[idx].matchLength != 0 || inSeqs[idx].offset != 0) && idx < inSeqsSize; ++idx) {
litLength = inSeqs[idx].litLength;
matchLength = inSeqs[idx].matchLength;
ll0 = litLength == 0;
offCode = ZSTD_finalizeOffCode(inSeqs[idx].offset, updatedRepcodes.rep, ll0);
updatedRepcodes = ZSTD_updateRep(updatedRepcodes.rep, offCode, ll0);
DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offCode, matchLength, litLength);
if (cctx->appliedParams.validateSequences) {
seqPos->posInSrc += litLength + matchLength;
FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize),
"Sequence validation failed");
}
ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offCode, matchLength - MINMATCH);
ip += matchLength + litLength;
}
ZSTD_memcpy(cctx->blockState.nextCBlock->rep, updatedRepcodes.rep, sizeof(repcodes_t));
if (inSeqs[idx].litLength) {
DEBUGLOG(6, "Storing last literals of size: %u", inSeqs[idx].litLength);
ZSTD_storeLastLiterals(&cctx->seqStore, ip, inSeqs[idx].litLength);
ip += inSeqs[idx].litLength;
seqPos->posInSrc += inSeqs[idx].litLength;
}
RETURN_ERROR_IF(ip != iend, corruption_detected, "Blocksize doesn't agree with block delimiter!");
seqPos->idx = idx+1;
return 0;
}
/* Returns the number of bytes to move the current read position back by. Only non-zero
* if we ended up splitting a sequence. Otherwise, it may return a ZSTD error if something
* went wrong.
*
* This function will attempt to scan through blockSize bytes represented by the sequences
* in inSeqs, storing any (partial) sequences.
*
* Occasionally, we may want to change the actual number of bytes we consumed from inSeqs to
* avoid splitting a match, or to avoid splitting a match such that it would produce a match
* smaller than MINMATCH. In this case, we return the number of bytes that we didn't read from this block.
*/
static size_t ZSTD_copySequencesToSeqStoreNoBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition* seqPos,
const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
const void* src, size_t blockSize) {
U32 idx = seqPos->idx;
U32 startPosInSequence = seqPos->posInSequence;
U32 endPosInSequence = seqPos->posInSequence + (U32)blockSize;
size_t dictSize;
BYTE const* ip = (BYTE const*)(src);
BYTE const* iend = ip + blockSize; /* May be adjusted if we decide to process fewer than blockSize bytes */
repcodes_t updatedRepcodes;
U32 bytesAdjustment = 0;
U32 finalMatchSplit = 0;
U32 litLength;
U32 matchLength;
U32 rawOffset;
U32 offCode;
if (cctx->cdict) {
dictSize = cctx->cdict->dictContentSize;
} else if (cctx->prefixDict.dict) {
dictSize = cctx->prefixDict.dictSize;
} else {
dictSize = 0;
}
DEBUGLOG(5, "ZSTD_copySequencesToSeqStore: idx: %u PIS: %u blockSize: %zu", idx, startPosInSequence, blockSize);
DEBUGLOG(5, "Start seq: idx: %u (of: %u ml: %u ll: %u)", idx, inSeqs[idx].offset, inSeqs[idx].matchLength, inSeqs[idx].litLength);
ZSTD_memcpy(updatedRepcodes.rep, cctx->blockState.prevCBlock->rep, sizeof(repcodes_t));
while (endPosInSequence && idx < inSeqsSize && !finalMatchSplit) {
const ZSTD_Sequence currSeq = inSeqs[idx];
litLength = currSeq.litLength;
matchLength = currSeq.matchLength;
rawOffset = currSeq.offset;
/* Modify the sequence depending on where endPosInSequence lies */
if (endPosInSequence >= currSeq.litLength + currSeq.matchLength) {
if (startPosInSequence >= litLength) {
startPosInSequence -= litLength;
litLength = 0;
matchLength -= startPosInSequence;
} else {
litLength -= startPosInSequence;
}
/* Move to the next sequence */
endPosInSequence -= currSeq.litLength + currSeq.matchLength;
startPosInSequence = 0;
idx++;
} else {
/* This is the final (partial) sequence we're adding from inSeqs, and endPosInSequence
does not reach the end of the match. So, we have to split the sequence */
DEBUGLOG(6, "Require a split: diff: %u, idx: %u PIS: %u",
currSeq.litLength + currSeq.matchLength - endPosInSequence, idx, endPosInSequence);
if (endPosInSequence > litLength) {
U32 firstHalfMatchLength;
litLength = startPosInSequence >= litLength ? 0 : litLength - startPosInSequence;
firstHalfMatchLength = endPosInSequence - startPosInSequence - litLength;
if (matchLength > blockSize && firstHalfMatchLength >= MINMATCH) {
/* Only ever split the match if it is larger than the block size */
U32 secondHalfMatchLength = currSeq.matchLength + currSeq.litLength - endPosInSequence;
if (secondHalfMatchLength < MINMATCH) {
/* Move the endPosInSequence backward so that it creates match of MINMATCH length */
endPosInSequence -= MINMATCH - secondHalfMatchLength;
bytesAdjustment = MINMATCH - secondHalfMatchLength;
firstHalfMatchLength -= bytesAdjustment;
}
matchLength = firstHalfMatchLength;
/* Flag that we split the last match - after storing the sequence, exit the loop,
but keep the value of endPosInSequence */
finalMatchSplit = 1;
} else {
/* Move the position in sequence backwards so that we don't split match, and break to store
* the last literals. We use the original currSeq.litLength as a marker for where endPosInSequence
* should go. We prefer to do this whenever it is not necessary to split the match, or if doing so
* would cause the first half of the match to be too small
*/
bytesAdjustment = endPosInSequence - currSeq.litLength;
endPosInSequence = currSeq.litLength;
break;
}
} else {
/* This sequence ends inside the literals, break to store the last literals */
break;
}
}
/* Check if this offset can be represented with a repcode */
{ U32 ll0 = (litLength == 0);
offCode = ZSTD_finalizeOffCode(rawOffset, updatedRepcodes.rep, ll0);
updatedRepcodes = ZSTD_updateRep(updatedRepcodes.rep, offCode, ll0);
}
if (cctx->appliedParams.validateSequences) {
seqPos->posInSrc += litLength + matchLength;
FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize),
"Sequence validation failed");
}
DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offCode, matchLength, litLength);
ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offCode, matchLength - MINMATCH);
ip += matchLength + litLength;
}
DEBUGLOG(5, "Ending seq: idx: %u (of: %u ml: %u ll: %u)", idx, inSeqs[idx].offset, inSeqs[idx].matchLength, inSeqs[idx].litLength);
assert(idx == inSeqsSize || endPosInSequence <= inSeqs[idx].litLength + inSeqs[idx].matchLength);
seqPos->idx = idx;
seqPos->posInSequence = endPosInSequence;
ZSTD_memcpy(cctx->blockState.nextCBlock->rep, updatedRepcodes.rep, sizeof(repcodes_t));
iend -= bytesAdjustment;
if (ip != iend) {
/* Store any last literals */
U32 lastLLSize = (U32)(iend - ip);
assert(ip <= iend);
DEBUGLOG(6, "Storing last literals of size: %u", lastLLSize);
ZSTD_storeLastLiterals(&cctx->seqStore, ip, lastLLSize);
seqPos->posInSrc += lastLLSize;
}
return bytesAdjustment;
}
typedef size_t (*ZSTD_sequenceCopier) (ZSTD_CCtx* cctx, ZSTD_sequencePosition* seqPos,
const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
const void* src, size_t blockSize);
static ZSTD_sequenceCopier ZSTD_selectSequenceCopier(ZSTD_sequenceFormat_e mode) {
ZSTD_sequenceCopier sequenceCopier = NULL;
assert(ZSTD_cParam_withinBounds(ZSTD_c_blockDelimiters, mode));
if (mode == ZSTD_sf_explicitBlockDelimiters) {
return ZSTD_copySequencesToSeqStoreExplicitBlockDelim;
} else if (mode == ZSTD_sf_noBlockDelimiters) {
return ZSTD_copySequencesToSeqStoreNoBlockDelim;
}
assert(sequenceCopier != NULL);
return sequenceCopier;
}
/* Compress, block-by-block, all of the sequences given.
*
* Returns the cumulative size of all compressed blocks (including their headers), otherwise a ZSTD error.
*/
static size_t ZSTD_compressSequences_internal(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* src, size_t srcSize) {
size_t cSize = 0;
U32 lastBlock;
size_t blockSize;
size_t compressedSeqsSize;
size_t remaining = srcSize;
ZSTD_sequencePosition seqPos = {0, 0, 0};
BYTE const* ip = (BYTE const*)src;
BYTE* op = (BYTE*)dst;
ZSTD_sequenceCopier sequenceCopier = ZSTD_selectSequenceCopier(cctx->appliedParams.blockDelimiters);
DEBUGLOG(4, "ZSTD_compressSequences_internal srcSize: %zu, inSeqsSize: %zu", srcSize, inSeqsSize);
/* Special case: empty frame */
if (remaining == 0) {
U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1);
RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "No room for empty frame block header");
MEM_writeLE32(op, cBlockHeader24);
op += ZSTD_blockHeaderSize;
dstCapacity -= ZSTD_blockHeaderSize;
cSize += ZSTD_blockHeaderSize;
}
while (remaining) {
size_t cBlockSize;
size_t additionalByteAdjustment;
lastBlock = remaining <= cctx->blockSize;
blockSize = lastBlock ? (U32)remaining : (U32)cctx->blockSize;
ZSTD_resetSeqStore(&cctx->seqStore);
DEBUGLOG(4, "Working on new block. Blocksize: %zu", blockSize);
additionalByteAdjustment = sequenceCopier(cctx, &seqPos, inSeqs, inSeqsSize, ip, blockSize);
FORWARD_IF_ERROR(additionalByteAdjustment, "Bad sequence copy");
blockSize -= additionalByteAdjustment;
/* If blocks are too small, emit as a nocompress block */
if (blockSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
cBlockSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cBlockSize, "Nocompress block failed");
DEBUGLOG(4, "Block too small, writing out nocompress block: cSize: %zu", cBlockSize);
cSize += cBlockSize;
ip += blockSize;
op += cBlockSize;
remaining -= blockSize;
dstCapacity -= cBlockSize;
continue;
}
compressedSeqsSize = ZSTD_entropyCompressSequences(&cctx->seqStore,
&cctx->blockState.prevCBlock->entropy, &cctx->blockState.nextCBlock->entropy,
&cctx->appliedParams,
op + ZSTD_blockHeaderSize /* Leave space for block header */, dstCapacity - ZSTD_blockHeaderSize,
blockSize,
cctx->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
cctx->bmi2);
FORWARD_IF_ERROR(compressedSeqsSize, "Compressing sequences of block failed");
DEBUGLOG(4, "Compressed sequences size: %zu", compressedSeqsSize);
if (!cctx->isFirstBlock &&
ZSTD_maybeRLE(&cctx->seqStore) &&
ZSTD_isRLE((BYTE const*)src, srcSize)) {
/* We don't want to emit our first block as a RLE even if it qualifies because
* doing so will cause the decoder (cli only) to throw a "should consume all input error."
* This is only an issue for zstd <= v1.4.3
*/
compressedSeqsSize = 1;
}
if (compressedSeqsSize == 0) {
/* ZSTD_noCompressBlock writes the block header as well */
cBlockSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cBlockSize, "Nocompress block failed");
DEBUGLOG(4, "Writing out nocompress block, size: %zu", cBlockSize);
} else if (compressedSeqsSize == 1) {
cBlockSize = ZSTD_rleCompressBlock(op, dstCapacity, *ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cBlockSize, "RLE compress block failed");
DEBUGLOG(4, "Writing out RLE block, size: %zu", cBlockSize);
} else {
U32 cBlockHeader;
/* Error checking and repcodes update */
ZSTD_confirmRepcodesAndEntropyTables(cctx);
if (cctx->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
cctx->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
/* Write block header into beginning of block*/
cBlockHeader = lastBlock + (((U32)bt_compressed)<<1) + (U32)(compressedSeqsSize << 3);
MEM_writeLE24(op, cBlockHeader);
cBlockSize = ZSTD_blockHeaderSize + compressedSeqsSize;
DEBUGLOG(4, "Writing out compressed block, size: %zu", cBlockSize);
}
cSize += cBlockSize;
DEBUGLOG(4, "cSize running total: %zu", cSize);
if (lastBlock) {
break;
} else {
ip += blockSize;
op += cBlockSize;
remaining -= blockSize;
dstCapacity -= cBlockSize;
cctx->isFirstBlock = 0;
}
}
return cSize;
}
size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size_t dstCapacity,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* src, size_t srcSize) {
BYTE* op = (BYTE*)dst;
size_t cSize = 0;
size_t compressedBlocksSize = 0;
size_t frameHeaderSize = 0;
/* Transparent initialization stage, same as compressStream2() */
DEBUGLOG(3, "ZSTD_compressSequences()");
assert(cctx != NULL);
FORWARD_IF_ERROR(ZSTD_CCtx_init_compressStream2(cctx, ZSTD_e_end, srcSize), "CCtx initialization failed");
/* Begin writing output, starting with frame header */
frameHeaderSize = ZSTD_writeFrameHeader(op, dstCapacity, &cctx->appliedParams, srcSize, cctx->dictID);
op += frameHeaderSize;
dstCapacity -= frameHeaderSize;
cSize += frameHeaderSize;
if (cctx->appliedParams.fParams.checksumFlag && srcSize) {
XXH64_update(&cctx->xxhState, src, srcSize);
}
/* cSize includes block header size and compressed sequences size */
compressedBlocksSize = ZSTD_compressSequences_internal(cctx,
op, dstCapacity,
inSeqs, inSeqsSize,
src, srcSize);
FORWARD_IF_ERROR(compressedBlocksSize, "Compressing blocks failed!");
cSize += compressedBlocksSize;
dstCapacity -= compressedBlocksSize;
if (cctx->appliedParams.fParams.checksumFlag) {
U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "no room for checksum");
DEBUGLOG(4, "Write checksum : %08X", (unsigned)checksum);
MEM_writeLE32((char*)dst + cSize, checksum);
cSize += 4;
}
DEBUGLOG(3, "Final compressed size: %zu", cSize);
return cSize;
}
/*====== Finalize ======*/
/*! ZSTD_flushStream() :

4
lib/compress/zstd_compress_internal.h
View File

@ -242,6 +242,10 @@ struct ZSTD_CCtx_params_s {
ZSTD_bufferMode_e inBufferMode;
ZSTD_bufferMode_e outBufferMode;
/* Sequence compression API */
ZSTD_sequenceFormat_e blockDelimiters;
int validateSequences;
/* Internal use, for createCCtxParams() and freeCCtxParams() only */
ZSTD_customMem customMem;
}; /* typedef'd to ZSTD_CCtx_params within "zstd.h" */

79
lib/zstd.h
View File

@ -417,6 +417,8 @@ typedef enum {
* ZSTD_c_enableDedicatedDictSearch
* ZSTD_c_stableInBuffer
* ZSTD_c_stableOutBuffer
* ZSTD_c_blockDelimiters
* ZSTD_c_validateSequences
* Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
* note : never ever use experimentalParam? names directly;
* also, the enums values themselves are unstable and can still change.
@ -430,7 +432,9 @@ typedef enum {
ZSTD_c_experimentalParam7=1004,
ZSTD_c_experimentalParam8=1005,
ZSTD_c_experimentalParam9=1006,
ZSTD_c_experimentalParam10=1007
ZSTD_c_experimentalParam10=1007,
ZSTD_c_experimentalParam11=1008,
ZSTD_c_experimentalParam12=1009
} ZSTD_cParameter;
typedef struct {
@ -1151,7 +1155,8 @@ typedef struct {
*
* Note: This field is optional. ZSTD_generateSequences() will calculate the value of
* 'rep', but repeat offsets do not necessarily need to be calculated from an external
* sequence provider's perspective.
* sequence provider's perspective. For example, ZSTD_compressSequences() does not
* use this 'rep' field at all (as of now).
*/
} ZSTD_Sequence;
@ -1298,8 +1303,8 @@ ZSTDLIB_API unsigned long long ZSTD_decompressBound(const void* src, size_t srcS
ZSTDLIB_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
typedef enum {
ZSTD_sf_explicitBlockDelimiters, /* Representation of ZSTD_Sequence contains explicit block delimiters */
ZSTD_sf_noBlockDelimiters /* Representation of ZSTD_Sequence has no block delimiters, sequences only */
ZSTD_sf_noBlockDelimiters = 0, /* Representation of ZSTD_Sequence has no block delimiters, sequences only */
ZSTD_sf_explicitBlockDelimiters = 1 /* Representation of ZSTD_Sequence contains explicit block delimiters */
} ZSTD_sequenceFormat_e;
/*! ZSTD_generateSequences() :
@ -1312,6 +1317,9 @@ typedef enum {
*
* zc can be used to insert custom compression params.
* This function invokes ZSTD_compress2
*
* The output of this function can be fed into ZSTD_compressSequences() with CCtx
* setting of ZSTD_c_blockDelimiters as ZSTD_sf_explicitBlockDelimiters
* @return : number of sequences generated
*/
@ -1324,10 +1332,45 @@ ZSTDLIB_API size_t ZSTD_generateSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
*
* As such, the final generated result has no explicit representation of block boundaries,
* and the final last literals segment is not represented in the sequences.
*
* The output of this function can be fed into ZSTD_compressSequences() with CCtx
* setting of ZSTD_c_blockDelimiters as ZSTD_sf_noBlockDelimiters
* @return : number of sequences left after merging
*/
ZSTDLIB_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, size_t seqsSize);
/*! ZSTD_compressSequences() :
* Compress an array of ZSTD_Sequence, generated from the original source buffer, into dst.
* If a dictionary is included, then the cctx should reference the dict. (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.)
* The entire source is compressed into a single frame.
*
* The compression behavior changes based on cctx params. In particular:
* If ZSTD_c_blockDelimiters == ZSTD_sf_noBlockDelimiters, the array of ZSTD_Sequence is expected to contain
* no block delimiters (defined in ZSTD_Sequence). Block boundaries are roughly determined based on
* the block size derived from the cctx, and sequences may be split. This is the default setting.
*
* If ZSTD_c_blockDelimiters == ZSTD_sf_explicitBlockDelimiters, the array of ZSTD_Sequence is expected to contain
* block delimiters (defined in ZSTD_Sequence). Behavior is undefined if no block delimiters are provided.
*
* If ZSTD_c_validateSequences == 0, this function will blindly accept the sequences provided. Invalid sequences cause undefined
* behavior. If ZSTD_c_validateSequences == 1, then if sequence is invalid (see doc/zstd_compression_format.md for
* specifics regarding offset/matchlength requirements) then the function will bail out and return an error.
*
* In addition to the two adjustable experimental params, other noteworthy cctx parameters are the compression level and window log.
* - The compression level accordingly adjusts the strength of the entropy coder, as it would in typical compression.
* - The window log affects offset validation: this function will return an error at higher debug levels if a provided offset
* is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md
*
* Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused.
* Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly,
* and cannot emit an RLE block that disagrees with the repcode history
* @return : final compressed size or a ZSTD error.
*/
ZSTDLIB_API size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size_t dstSize,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* src, size_t srcSize);
/***************************************
* Memory management
***************************************/
@ -1725,6 +1768,34 @@ ZSTDLIB_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* pre
*/
#define ZSTD_c_stableOutBuffer ZSTD_c_experimentalParam10
/* ZSTD_c_blockDelimiters
* Default is 0 == ZSTD_sf_noBlockDelimiters.
*
* For use with sequence compression API: ZSTD_compressSequences().
*
* Designates whether or not the given array of ZSTD_Sequence contains block delimiters
* and last literals, which are defined as sequences with offset == 0 and matchLength == 0.
* See the definition of ZSTD_Sequence for more specifics.
*/
#define ZSTD_c_blockDelimiters ZSTD_c_experimentalParam11
/* ZSTD_c_validateSequences
* Default is 0 == disabled. Set to 1 to enable sequence validation.
*
* For use with sequence compression API: ZSTD_compressSequences().
* Designates whether or not we validate sequences provided to ZSTD_compressSequences()
* during function execution.
*
* Without validation, providing a sequence that does not conform to the zstd spec will cause
* undefined behavior, and may produce a corrupted block.
*
* With validation enabled, a if sequence is invalid (see doc/zstd_compression_format.md for
* specifics regarding offset/matchlength requirements) then the function will bail out and
* return an error.
*
*/
#define ZSTD_c_validateSequences ZSTD_c_experimentalParam12
/*! ZSTD_CCtx_getParameter() :
* Get the requested compression parameter value, selected by enum ZSTD_cParameter,
* and store it into int* value.

59
tests/fuzzer.c
View File

@ -2739,6 +2739,65 @@ static int basicUnitTests(U32 const seed, double compressibility)
free(seqs);
}
DISPLAYLEVEL(3, "OK \n");
DISPLAYLEVEL(3, "test%3i : ZSTD_getSequences followed by ZSTD_compressSequences : ", testNb++);
{
size_t srcSize = 500 KB;
BYTE* src = (BYTE*)CNBuffer;
BYTE* dst = (BYTE*)compressedBuffer;
size_t dstSize = ZSTD_compressBound(srcSize);
size_t decompressSize = srcSize;
char* decompressBuffer = (char*)malloc(decompressSize);
size_t compressedSize;
size_t dSize;
ZSTD_CCtx* cctx = ZSTD_createCCtx();
ZSTD_Sequence* seqs = (ZSTD_Sequence*)malloc(srcSize * sizeof(ZSTD_Sequence));
size_t seqsSize;
if (seqs == NULL) goto _output_error;
assert(cctx != NULL);
/* Populate src with random data */
RDG_genBuffer(CNBuffer, srcSize, compressibility, 0., seed);
/* Test with block delimiters roundtrip */
seqsSize = ZSTD_generateSequences(cctx, seqs, srcSize, src, srcSize);
ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_explicitBlockDelimiters);
compressedSize = ZSTD_compressSequences(cctx, dst, dstSize, seqs, seqsSize, src, srcSize);
if (ZSTD_isError(compressedSize)) {
DISPLAY("Error in sequence compression with block delims\n");
goto _output_error;
}
dSize = ZSTD_decompress(decompressBuffer, decompressSize, dst, compressedSize);
if (ZSTD_isError(dSize)) {
DISPLAY("Error in sequence compression roundtrip with block delims\n");
goto _output_error;
}
assert(!memcmp(decompressBuffer, src, srcSize));
/* Test with no block delimiters roundtrip */
seqsSize = ZSTD_mergeBlockDelimiters(seqs, seqsSize);
ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters);
compressedSize = ZSTD_compressSequences(cctx, dst, dstSize, seqs, seqsSize, src, srcSize);
if (ZSTD_isError(compressedSize)) {
DISPLAY("Error in sequence compression with no block delims\n");
goto _output_error;
}
dSize = ZSTD_decompress(decompressBuffer, decompressSize, dst, compressedSize);
if (ZSTD_isError(dSize)) {
DISPLAY("Error in sequence compression roundtrip with no block delims\n");
goto _output_error;
}
assert(!memcmp(decompressBuffer, src, srcSize));
ZSTD_freeCCtx(cctx);
free(decompressBuffer);
free(seqs);
}
DISPLAYLEVEL(3, "OK \n");
/* Multiple blocks of zeros test */
#define LONGZEROSLENGTH 1000000 /* 1MB of zeros */