facebook/zstd
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add unit tests and fuzzer param

Browse Source
This commit is contained in:
senhuang42 2020-12-29 15:56:13 -05:00 committed by Sen Huang
parent de52de1347
commit e2bb215117
4 changed files with 200 additions and 159 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

349
lib/compress/zstd_compress.c
View File

@ -29,7 +29,6 @@
#include "zstd_opt.h"
#include "zstd_ldm.h"
#include "zstd_compress_superblock.h"
#include <stdio.h>
/* ***************************************************************
* Tuning parameters
@ -2193,28 +2192,42 @@ static int ZSTD_useTargetCBlockSize(const ZSTD_CCtx_params* cctxParams)
return (cctxParams->targetCBlockSize != 0);
}
/* ZSTD_buildSequencesStatistics():
* Returns the size of the statistics for a given set of sequences, or a ZSTD error code
*/
/* ZSTD_useBlockSplitting():
* Returns if block splitting param is being used
* If used, compression will do best effort to split a block in order to improve compression ratio.
* Returns 1 if true, 0 otherwise. */
static int ZSTD_useBlockSplitting(const ZSTD_CCtx_params* cctxParams)
{
DEBUGLOG(5, "ZSTD_useBlockSplitting(splitBlocks=%d)", cctxParams->splitBlocks);
return (cctxParams->splitBlocks != 0);
}
/* ZSTD_buildSequencesStatistics():
* Returns the size of the statistics for a given set of sequences, or a ZSTD error code,
*/
MEM_STATIC size_t
ZSTD_buildSequencesStatistics(const BYTE* const ofCodeTable,
const BYTE* const llCodeTable,
const BYTE* const mlCodeTable,
FSE_CTable* CTable_LitLength,
FSE_CTable* CTable_OffsetBits,
FSE_CTable* CTable_MatchLength,
size_t nbSeq,
ZSTD_buildSequencesStatistics(seqStore_t* seqStorePtr, size_t nbSeq,
const ZSTD_fseCTables_t* prevEntropy, ZSTD_fseCTables_t* nextEntropy,
BYTE* dst, const BYTE* const dstEnd,
ZSTD_strategy strategy, BYTE* lastNCount, ZSTD_fseCTablesMetadata_t* fseMetadata,
void* countWorkspace, void* entropyWorkspace, size_t entropyWkspSize) {
ZSTD_strategy strategy, BYTE** lastNCount, ZSTD_fseCTablesMetadata_t* fseMetadata,
void* entropyWorkspace, size_t entropyWkspSize) {
U32 LLtype, Offtype, MLtype; /* compressed, raw or rle */
BYTE* const ostart = dst;
const BYTE* const oend = dstEnd;
BYTE* op = ostart;
BYTE* seqHead = op++;
unsigned* const countWorkspace = (unsigned*)entropyWorkspace;
FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
const BYTE* const ofCodeTable = seqStorePtr->ofCode;
const BYTE* const llCodeTable = seqStorePtr->llCode;
const BYTE* const mlCodeTable = seqStorePtr->mlCode;
/* convert length/distances into codes */
ZSTD_seqToCodes(seqStorePtr);
assert(op <= oend);
/* build CTable for Literal Lengths */
{ unsigned max = MaxLL;
@ -2238,7 +2251,7 @@ ZSTD_buildSequencesStatistics(const BYTE* const ofCodeTable,
entropyWorkspace, entropyWkspSize);
FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for LitLens failed");
if (LLtype == set_compressed)
lastNCount = op;
*lastNCount = op;
op += countSize;
if (fseMetadata) {
if (LLtype == set_compressed) fseMetadata->lastCountSize = countSize;
@ -2270,7 +2283,7 @@ ZSTD_buildSequencesStatistics(const BYTE* const ofCodeTable,
entropyWorkspace, entropyWkspSize);
FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for Offsets failed");
if (Offtype == set_compressed)
lastNCount = op;
*lastNCount = op;
op += countSize;
if (fseMetadata) {
if (Offtype == set_compressed) fseMetadata->lastCountSize = countSize;
@ -2300,7 +2313,7 @@ ZSTD_buildSequencesStatistics(const BYTE* const ofCodeTable,
entropyWorkspace, entropyWkspSize);
FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for MatchLengths failed");
if (MLtype == set_compressed)
lastNCount = op;
*lastNCount = op;
op += countSize;
if (fseMetadata) {
if (MLtype == set_compressed) fseMetadata->lastCountSize = countSize;
@ -2330,7 +2343,7 @@ ZSTD_entropyCompressSequences_internal(seqStore_t* seqStorePtr,
FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
U32 entropyStatisticsSize;
size_t entropyStatisticsSize;
const seqDef* const sequences = seqStorePtr->sequencesStart;
const size_t nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
const BYTE* const ofCodeTable = seqStorePtr->ofCode;
@ -2361,7 +2374,6 @@ ZSTD_entropyCompressSequences_internal(seqStore_t* seqStorePtr,
bmi2);
FORWARD_IF_ERROR(cSize, "ZSTD_compressLiterals failed");
assert(cSize <= dstCapacity);
DEBUGLOG(2, "Actual litSize: %zu", cSize);
op += cSize;
}
@ -2386,14 +2398,11 @@ ZSTD_entropyCompressSequences_internal(seqStore_t* seqStorePtr,
return (size_t)(op - ostart);
}
/* convert length/distances into codes */
ZSTD_seqToCodes(seqStorePtr);
/* build stats for sequences */
entropyStatisticsSize = ZSTD_buildSequencesStatistics(ofCodeTable, llCodeTable, mlCodeTable,
CTable_LitLength, CTable_OffsetBits, CTable_MatchLength,
entropyStatisticsSize = ZSTD_buildSequencesStatistics(seqStorePtr,
nbSeq, &prevEntropy->fse, &nextEntropy->fse, op, oend,
strategy, lastNCount, NULL /* no fseMetadata needed */,
count, entropyWorkspace, entropyWkspSize);
strategy, &lastNCount, NULL /* no fseMetadata needed */,
entropyWorkspace, entropyWkspSize);
FORWARD_IF_ERROR(entropyStatisticsSize, "FSE statistics building failed!");
op += entropyStatisticsSize;
@ -2422,7 +2431,6 @@ ZSTD_entropyCompressSequences_internal(seqStore_t* seqStorePtr,
"emitting an uncompressed block.");
return 0;
}
DEBUGLOG(2, "Actual seqSize: %zu", bitstreamSize);
}
DEBUGLOG(5, "compressed block size : %u", (unsigned)(op - ostart));
@ -2762,7 +2770,7 @@ static void writeBlockHeader(void* op, size_t cSize, size_t blockSize, U32 lastB
}
/** ZSTD_buildBlockEntropyStats_literals() :
* Builds entropy for the super-block literals.
* Builds entropy for the literals.
* Stores literals block type (raw, rle, compressed, repeat) and
* huffman description table to hufMetadata.
* @return : size of huffman description table or error code */
@ -2780,7 +2788,7 @@ static size_t ZSTD_buildBlockEntropyStats_literals(void* const src, size_t srcSi
const size_t countWkspSize = (HUF_SYMBOLVALUE_MAX + 1) * sizeof(unsigned);
BYTE* const nodeWksp = countWkspStart + countWkspSize;
const size_t nodeWkspSize = wkspEnd-nodeWksp;
unsigned maxSymbolValue = 255;
unsigned maxSymbolValue = HUF_SYMBOLVALUE_MAX;
unsigned huffLog = HUF_TABLELOG_DEFAULT;
HUF_repeat repeat = prevHuf->repeatMode;
DEBUGLOG(5, "ZSTD_buildBlockEntropyStats_literals (srcSize=%zu)", srcSize);
@ -2795,7 +2803,9 @@ static size_t ZSTD_buildBlockEntropyStats_literals(void* const src, size_t srcSi
}
/* small ? don't even attempt compression (speed opt) */
# define COMPRESS_LITERALS_SIZE_MIN 63
#ifndef COMPRESS_LITERALS_SIZE_MIN
#define COMPRESS_LITERALS_SIZE_MIN 63
#endif
{ size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
if (srcSize <= minLitSize) {
DEBUGLOG(5, "set_basic - too small");
@ -2864,7 +2874,7 @@ static size_t ZSTD_buildBlockEntropyStats_literals(void* const src, size_t srcSi
}
/** ZSTD_buildBlockEntropyStats_sequences() :
* Builds entropy for the super-block sequences.
* Builds entropy for the sequences.
* Stores symbol compression modes and fse table to fseMetadata.
* @return : size of fse tables or error code */
static size_t ZSTD_buildBlockEntropyStats_sequences(seqStore_t* seqStorePtr,
@ -2874,38 +2884,19 @@ static size_t ZSTD_buildBlockEntropyStats_sequences(seqStore_t* seqStorePtr,
ZSTD_fseCTablesMetadata_t* fseMetadata,
void* workspace, size_t wkspSize)
{
/* Size the workspaces */
BYTE* const wkspStart = (BYTE*)workspace;
BYTE* const wkspEnd = wkspStart + wkspSize;
BYTE* const countWkspStart = wkspStart;
unsigned* const countWksp = (unsigned*)workspace;
const size_t countWkspSize = (MaxSeq + 1) * sizeof(unsigned);
BYTE* const cTableWksp = countWkspStart + countWkspSize;
const size_t cTableWkspSize = wkspEnd-cTableWksp;
ZSTD_strategy const strategy = cctxParams->cParams.strategy;
const BYTE* const ofCodeTable = seqStorePtr->ofCode;
const BYTE* const llCodeTable = seqStorePtr->llCode;
const BYTE* const mlCodeTable = seqStorePtr->mlCode;
FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
BYTE* const ostart = fseMetadata->fseTablesBuffer;
BYTE* const oend = ostart + sizeof(fseMetadata->fseTablesBuffer);
BYTE* op = ostart;
BYTE* lastNCount = NULL;
assert(cTableWkspSize >= (1 << MaxFSELog) * sizeof(FSE_FUNCTION_TYPE));
DEBUGLOG(5, "ZSTD_buildBlockEntropyStats_sequences (nbSeq=%zu)", nbSeq);
ZSTD_memset(workspace, 0, wkspSize);
fseMetadata->lastCountSize = 0;
return ZSTD_buildSequencesStatistics(ofCodeTable, llCodeTable, mlCodeTable,
CTable_LitLength, CTable_OffsetBits, CTable_MatchLength,
nbSeq, prevEntropy, nextEntropy, op, oend,
strategy, lastNCount, fseMetadata,
countWksp, cTableWksp, cTableWkspSize);
return ZSTD_buildSequencesStatistics(seqStorePtr, nbSeq, prevEntropy, nextEntropy, op, oend,
strategy, &lastNCount, fseMetadata,
workspace, wkspSize);
}
@ -2937,6 +2928,7 @@ size_t ZSTD_buildBlockEntropyStats(seqStore_t* seqStorePtr,
return 0;
}
/* Returns the size estimate for the literals section (header + content) of a block */
static size_t ZSTD_estimateSubBlockSize_literal(const BYTE* literals, size_t litSize,
const ZSTD_hufCTables_t* huf,
const ZSTD_hufCTablesMetadata_t* hufMetadata,
@ -2962,6 +2954,7 @@ static size_t ZSTD_estimateSubBlockSize_literal(const BYTE* literals, size_t lit
return 0;
}
/* Returns the size estimate for the FSE-compressed symbols (of, ml, ll) of a block */
static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
const BYTE* codeTable, unsigned maxCode,
size_t nbSeq, const FSE_CTable* fseCTable,
@ -2989,7 +2982,6 @@ static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
cSymbolTypeSizeEstimateInBits = ZSTD_fseBitCost(fseCTable, countWksp, max);
}
if (ZSTD_isError(cSymbolTypeSizeEstimateInBits)) {
DEBUGLOG(2, "Returning inaccurate");
return nbSeq * 10;
}
while (ctp < ctEnd) {
@ -2997,9 +2989,10 @@ static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
else cSymbolTypeSizeEstimateInBits += *ctp; /* for offset, offset code is also the number of additional bits */
ctp++;
}
return cSymbolTypeSizeEstimateInBits / 8;
return cSymbolTypeSizeEstimateInBits >> 3;
}
/* Returns the size estimate for the sequences section (header + content) of a block */
static size_t ZSTD_estimateSubBlockSize_sequences(const BYTE* ofCodeTable,
const BYTE* llCodeTable,
const BYTE* mlCodeTable,
@ -3009,7 +3002,7 @@ static size_t ZSTD_estimateSubBlockSize_sequences(const BYTE* ofCodeTable,
void* workspace, size_t wkspSize,
int writeEntropy)
{
size_t sequencesSectionHeaderSize = 3; /* Use hard coded size of 3 bytes */
size_t sequencesSectionHeaderSize = 1 /* seqHead */ + 1 /* min seqSize size */ + (nbSeq >= 128) + (nbSeq >= LONGNBSEQ);
size_t cSeqSizeEstimate = 0;
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->ofType, ofCodeTable, MaxOff,
nbSeq, fseTables->offcodeCTable, NULL,
@ -3027,6 +3020,7 @@ static size_t ZSTD_estimateSubBlockSize_sequences(const BYTE* ofCodeTable,
return cSeqSizeEstimate + sequencesSectionHeaderSize;
}
/* Returns the size estimate for a given stream of literals, of, ll, ml */
size_t ZSTD_estimateSubBlockSize(const BYTE* literals, size_t litSize,
const BYTE* ofCodeTable,
const BYTE* llCodeTable,
@ -3098,21 +3092,21 @@ static size_t ZSTD_countSeqStoreMatchBytes(const seqStore_t* seqStore) {
}
/* Derives the seqStore that is a chunk of the originalSeqStore from [startIdx, endIdx).
* Stores the result in resultSeqStore.
*/
static void ZSTD_deriveSeqStoreChunk(seqStore_t* resultSeqStore, const seqStore_t* originalSeqStore,
size_t startIdx, size_t endIdx) {
BYTE* const litEnd = originalSeqStore->lit;
seqDef* const seqEnd = originalSeqStore->sequences;
U32 literalsBytes;
U32 literalsBytesPreceding = 0;
*resultSeqStore = *originalSeqStore;
/* First calculate the number of literal bytes before startIdx */
if (startIdx > 0) {
resultSeqStore->sequences = originalSeqStore->sequencesStart + startIdx;
literalsBytesPreceding = ZSTD_countSeqStoreLiteralsBytes(resultSeqStore);
}
/* Move longLengthPos into the correct position if necessary */
if (originalSeqStore->longLengthID != 0) {
if (originalSeqStore->longLengthPos < startIdx || originalSeqStore->longLengthPos > endIdx) {
resultSeqStore->longLengthID = 0;
@ -3125,6 +3119,7 @@ static void ZSTD_deriveSeqStoreChunk(seqStore_t* resultSeqStore, const seqStore_
literalsBytes = ZSTD_countSeqStoreLiteralsBytes(resultSeqStore);
resultSeqStore->litStart += literalsBytesPreceding;
if (endIdx == (size_t)(originalSeqStore->sequences - originalSeqStore->sequencesStart)) {
/* This accounts for possible last literals if the derived chunk reaches the end of the block */
resultSeqStore->lit = litEnd;
} else {
resultSeqStore->lit = resultSeqStore->litStart+literalsBytes;
@ -3137,14 +3132,14 @@ static void ZSTD_deriveSeqStoreChunk(seqStore_t* resultSeqStore, const seqStore_
/* ZSTD_compressSequences_singleBlock():
* Compresses a seqStore into a block with a block header, into the buffer dst.
*
* Returns the size of that block or a ZSTD error code
* Returns the total size of that block (including header) or a ZSTD error code.
*
* TODO: Migrate compressBlock_internal and compressSequences_internal to use this as well
*/
/* TODO: Migrate compressBlock_internal and compressSequences_internal to use this as well */
static size_t ZSTD_compressSequences_singleBlock(ZSTD_CCtx* zc, seqStore_t* seqStore,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 lastBlock) {
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 lastBlock) {
const U32 rleMaxLength = 25;
BYTE* op = (BYTE*)dst;
const BYTE* ip = (const BYTE*)src;
@ -3159,7 +3154,6 @@ static size_t ZSTD_compressSequences_singleBlock(ZSTD_CCtx* zc, seqStore_t* seqS
if (!zc->isFirstBlock &&
cSeqsSize < rleMaxLength &&
ZSTD_maybeRLE(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."
@ -3179,17 +3173,17 @@ static size_t ZSTD_compressSequences_singleBlock(ZSTD_CCtx* zc, seqStore_t* seqS
if (cSeqsSize == 0) {
cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, srcSize, lastBlock);
FORWARD_IF_ERROR(cSize, "Nocompress block failed");
DEBUGLOG(2, "1: Writing out nocompress block, size: %zu", cSize);
DEBUGLOG(4, "Writing out nocompress block, size: %zu", cSize);
} else if (cSeqsSize == 1) {
cSize = ZSTD_rleCompressBlock(op, dstCapacity, *ip, srcSize, lastBlock);
FORWARD_IF_ERROR(cSize, "RLE compress block failed");
DEBUGLOG(2, "1: Writing out RLE block, size: %zu", cSize);
DEBUGLOG(4, "Writing out RLE block, size: %zu", cSize);
} else {
/* Error checking and repcodes update */
ZSTD_confirmRepcodesAndEntropyTables(zc);
writeBlockHeader(op, cSeqsSize, srcSize, lastBlock);
cSize = ZSTD_blockHeaderSize + cSeqsSize;
DEBUGLOG(3, "1: Writing out compressed block, size: %zu", cSize);
DEBUGLOG(4, "Writing out compressed block, size: %zu", cSize);
}
return cSize;
}
@ -3204,117 +3198,149 @@ typedef struct {
#define MAX_NB_SPLITS 196
/* Helper function to perform the recursive search for block splits.
* Estimates the cost of the original seqStore, and estimates the cost of splitting the sequences in half.
* If advantageous to split, then we recursive down the two sub-blocks.
* The recursion depth is capped by a heuristic minimum number of sequences, defined by MIN_SEQUENCES_BLOCK_SPLITTING.
* In practice, this means the absolute largest recursion depth is 10 == log2(maxNbSeqInBlock/MIN_SEQUENCES_BLOCK_SPLITTING).
* Estimates the cost of seqStore prior to split, and estimates the cost of splitting the sequences in half.
* If advantageous to split, then we recurse down the two sub-blocks. If not, or if an error occurred in estimation, then
* we do not recurse.
*
* Returns the sequence index at which to split, or 0 if we should not split.
* Note: The recursion depth is capped by a heuristic minimum number of sequences, defined by MIN_SEQUENCES_BLOCK_SPLITTING.
* In theory, this means the absolute largest recursion depth is 10 == log2(maxNbSeqInBlock/MIN_SEQUENCES_BLOCK_SPLITTING).
* In practice, recursion depth usually doesn't go beyond 4.
*
* Furthermore, the number of splits is capped by MAX_NB_SPLITS. At MAX_NB_SPLITS == 196 with the current existing blockSize
* maximum of 128 KB, this value is actually impossible to reach.
*/
static size_t deriveBlockBoundsHelper(ZSTD_CCtx* zc, seqStoreSplits* splits, size_t startIdx, size_t endIdx, const seqStore_t* origSeqStore) {
seqStore_t origSeqStoreChunk;
static void ZSTD_deriveBlockSplitsHelper(seqStoreSplits* splits, size_t startIdx, size_t endIdx,
const ZSTD_CCtx* zc, const seqStore_t* origSeqStore) {
seqStore_t fullSeqStoreChunk;
seqStore_t firstHalfSeqStore;
seqStore_t secondHalfSeqStore;
size_t estimatedOriginalSize;
size_t estimatedFirstHalfSize;
size_t estimatedSecondHalfSize;
size_t midIdx = (startIdx + endIdx)/2;
if (endIdx - startIdx < MIN_SEQUENCES_BLOCK_SPLITTING || splits->idx >= MAX_NB_SPLITS) {
return 0;
return;
}
ZSTD_deriveSeqStoreChunk(&origSeqStoreChunk, origSeqStore, startIdx, endIdx);
ZSTD_deriveSeqStoreChunk(&firstHalfSeqStore, origSeqStore, startIdx, (startIdx + endIdx)/2);
ZSTD_deriveSeqStoreChunk(&secondHalfSeqStore, origSeqStore, (startIdx + endIdx)/2, endIdx);
estimatedOriginalSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(&origSeqStoreChunk, zc);
ZSTD_deriveSeqStoreChunk(&fullSeqStoreChunk, origSeqStore, startIdx, endIdx);
ZSTD_deriveSeqStoreChunk(&firstHalfSeqStore, origSeqStore, startIdx, midIdx);
ZSTD_deriveSeqStoreChunk(&secondHalfSeqStore, origSeqStore, midIdx, endIdx);
estimatedOriginalSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(&fullSeqStoreChunk, zc);
estimatedFirstHalfSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(&firstHalfSeqStore, zc);
estimatedSecondHalfSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(&secondHalfSeqStore, zc);
if (ZSTD_isError(estimatedOriginalSize) || ZSTD_isError(estimatedFirstHalfSize) || ZSTD_isError(estimatedSecondHalfSize)) {
return;
}
if (estimatedFirstHalfSize + estimatedSecondHalfSize < estimatedOriginalSize) {
deriveBlockBoundsHelper(zc, splits, startIdx, (startIdx + endIdx)/2, origSeqStore);
splits->splitLocations[splits->idx] = (startIdx + endIdx)/2;
ZSTD_deriveBlockSplitsHelper(splits, startIdx, midIdx, zc, origSeqStore);
splits->splitLocations[splits->idx] = midIdx;
splits->idx++;
deriveBlockBoundsHelper(zc, splits, (startIdx + endIdx)/2, endIdx, origSeqStore);
return (startIdx + endIdx)/2;
} else {
return 0;
ZSTD_deriveBlockSplitsHelper(splits, midIdx, endIdx, zc, origSeqStore);
}
}
/* Base recursive function. Populates a table of partitions indices.
/* Base recursive function. Populates a table with intra-block partition indices that can improve compression ratio.
*
* Returns the number of splits made (which equals the size of the partition table - 1).
*/
static size_t deriveBlockBounds(ZSTD_CCtx* zc, void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 partitions[], U32 nbSeq) {
seqStoreSplits splits;
splits.idx = 0;
splits.splitLocations = partitions;
deriveBlockBoundsHelper(zc, &splits, 0, nbSeq, &zc->seqStore);
static size_t ZSTD_deriveBlockSplits(ZSTD_CCtx* zc, U32 partitions[], U32 nbSeq) {
seqStoreSplits splits = {partitions, 0};
if (nbSeq <= 4) {
/* Refuse to try and split anything with less than 4 sequences */
return 0;
}
ZSTD_deriveBlockSplitsHelper(&splits, 0, nbSeq, zc, &zc->seqStore);
splits.splitLocations[splits.idx] = nbSeq;
return splits.idx;
}
/* ZSTD_compressBlock_splitBlock():
* Attempts to split a given block into multiple (currently 2) blocks to improve compression ratio.
* Attempts to split a given block into multiple blocks to improve compression ratio.
*
* Returns 0 if it would not be advantageous to split the block. Otherwise, returns the combined size
* of the multiple blocks, or a ZSTD error code.
* Returns combined size of all blocks (which includes headers), or a ZSTD error code.
*/
static size_t ZSTD_compressBlock_splitBlock(ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize, U32 lastBlock, U32 nbSeq) {
static size_t ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc, void* dst, size_t dstCapacity,
const void* src, size_t blockSize, U32 lastBlock, U32 nbSeq) {
size_t cSize = 0;
const BYTE* ip = (const BYTE*)src;
BYTE* op = (BYTE*)dst;
seqStore_t firstHalfSeqStore;
seqStore_t secondHalfSeqStore;
size_t cSizeFirstHalf;
size_t cSizeSecondHalf;
U32 partitions[MAX_NB_SPLITS];
size_t i = 0;
size_t startIdx = 0;
size_t endIdx;
size_t srcBytesTotal = 0;
size_t numSplits = ZSTD_deriveBlockSplits(zc, partitions, nbSeq);
DEBUGLOG(5, "ZSTD_compressBlock_splitBlock (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
(unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
(unsigned)zc->blockState.matchState.nextToUpdate);
{
U32 partitions[MAX_NB_SPLITS];
size_t numSplits = deriveBlockBounds(zc, dst, dstCapacity, src, srcSize, partitions, nbSeq);
size_t i = 0;
size_t startIdx = 0;
size_t endIdx = 0;
size_t srcBytesCum = 0;
if (numSplits == 0) {
return 0;
}
while (i <= numSplits) {
endIdx = partitions[i];
seqStore_t chunkSeqStore = zc->seqStore;
ZSTD_deriveSeqStoreChunk(&chunkSeqStore, &zc->seqStore, startIdx, endIdx);
size_t srcBytes = ZSTD_countSeqStoreLiteralsBytes(&chunkSeqStore) + ZSTD_countSeqStoreMatchBytes(&chunkSeqStore);
size_t lastBlock = lastBlock && (nbSeq == endIdx);
srcBytesCum += srcBytes;
if (endIdx == nbSeq) {
/* This is the final partition, need to account for last literals */
srcBytes += zc->blockSize - srcBytesCum;
srcBytesCum += zc->blockSize - srcBytesCum;
}
size_t cSizeChunk = ZSTD_compressSequences_singleBlock(zc, &chunkSeqStore, op, dstCapacity, ip, srcBytes, lastBlock);
{
ZSTD_memcpy(zc->blockState.nextCBlock->rep, zc->blockState.prevCBlock->rep, sizeof(U32)*ZSTD_REP_NUM);
ip += srcBytes;
op += cSizeChunk;
dstCapacity -= cSizeChunk;
}
startIdx = partitions[i];
cSize += cSizeChunk;
++i;
}
if (numSplits == 0) {
size_t cSizeSingleBlock = ZSTD_compressSequences_singleBlock(zc, &zc->seqStore, op, dstCapacity, ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cSizeSingleBlock, "Compressing single block from splitBlock_internal() failed!");
return cSizeSingleBlock;
}
for (i = 0; i <= numSplits; ++i) {
seqStore_t chunkSeqStore;
size_t srcBytes;
size_t cSizeChunk;
U32 lastBlockActual;
endIdx = partitions[i];
ZSTD_deriveSeqStoreChunk(&chunkSeqStore, &zc->seqStore, startIdx, endIdx);
srcBytes = ZSTD_countSeqStoreLiteralsBytes(&chunkSeqStore) + ZSTD_countSeqStoreMatchBytes(&chunkSeqStore);
lastBlockActual = lastBlock && (nbSeq == endIdx);
srcBytesTotal += srcBytes;
if (i == numSplits) {
/* This is the final partition, need to account for possible last literals */
srcBytes += blockSize - srcBytesTotal;
}
cSizeChunk = ZSTD_compressSequences_singleBlock(zc, &chunkSeqStore, op, dstCapacity, ip, srcBytes, lastBlockActual);
FORWARD_IF_ERROR(cSizeChunk, "Compressing chunk failed!");
ZSTD_memcpy(zc->blockState.nextCBlock->rep, zc->blockState.prevCBlock->rep, sizeof(U32)*ZSTD_REP_NUM);
ip += srcBytes;
op += cSizeChunk;
dstCapacity -= cSizeChunk;
cSize += cSizeChunk;
startIdx = partitions[i];
}
return cSize;
}
static size_t ZSTD_compressBlock_splitBlock(ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize, U32 lastBlock) {
const BYTE* ip = (const BYTE*)src;
BYTE* op = (BYTE*)dst;
size_t nbSeq;
size_t cSize;
DEBUGLOG(4, "ZSTD_compressBlock_splitBlock");
{ const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
if (bss == ZSTDbss_noCompress) {
cSize = 0;
if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, srcSize, lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
return cSize;
}
nbSeq = (size_t)(zc->seqStore.sequences - zc->seqStore.sequencesStart);
}
assert(zc->appliedParams.splitBlocks == 1);
cSize = ZSTD_compressBlock_splitBlock_internal(zc, dst, dstCapacity, src, srcSize, lastBlock, nbSeq);
FORWARD_IF_ERROR(cSize, "Splitting blocks failed!");
return cSize;
}
static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize, U32 frame, U32 lastBlock)
const void* src, size_t srcSize, U32 frame)
{
/* This the upper bound for the length of an rle block.
* This isn't the actual upper bound. Finding the real threshold
@ -3322,7 +3348,6 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
*/
const U32 rleMaxLength = 25;
size_t cSize;
size_t nbSeq;
const BYTE* ip = (const BYTE*)src;
BYTE* op = (BYTE*)dst;
DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
@ -3332,23 +3357,19 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
{ const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
nbSeq = (size_t)(zc->seqStore.sequences - zc->seqStore.sequencesStart);
}
zc->appliedParams.splitBlocks = 1; /* remove */
if (zc->appliedParams.splitBlocks && nbSeq >= 2) {
size_t splitBlocksCompressedSize;
splitBlocksCompressedSize = ZSTD_compressBlock_splitBlock(zc, dst, dstCapacity, src, srcSize, lastBlock, nbSeq);
if (splitBlocksCompressedSize != 0) {
return splitBlocksCompressedSize;
}
if (zc->seqCollector.collectSequences) {
ZSTD_copyBlockSequences(zc);
ZSTD_confirmRepcodesAndEntropyTables(zc);
return 0;
}
/* encode sequences and literals */
cSize = ZSTD_entropyCompressSequences(&zc->seqStore,
&zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
&zc->appliedParams,
op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
dst, dstCapacity,
srcSize,
zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
zc->bmi2);
@ -3382,13 +3403,7 @@ out:
*/
if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
if (cSize == 0) {
cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, srcSize, lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
} else {
writeBlockHeader(op, cSize, srcSize, lastBlock);
cSize += ZSTD_blockHeaderSize;
}
return cSize;
}
@ -3498,7 +3513,7 @@ static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms,
* Frame is supposed already started (header already produced)
* @return : compressed size, or an error code
*/
static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
static size_t ZSTD_compress_frameChunk(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 lastFrameChunk)
@ -3538,13 +3553,29 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_targetCBlockSize failed");
assert(cSize > 0);
assert(cSize <= blockSize + ZSTD_blockHeaderSize);
} else if (ZSTD_useBlockSplitting(&cctx->appliedParams)) {
cSize = ZSTD_compressBlock_splitBlock(cctx, op, dstCapacity, ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_splitBlock failed");
assert(cSize > 0);
} else {
cSize = ZSTD_compressBlock_internal(cctx,
op, dstCapacity,
ip, blockSize, 1 /* frame */, lastBlock);
op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
ip, blockSize, 1 /* frame */);
FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_internal failed");
if (cSize == 0) { /* block is not compressible */
cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
} else {
U32 const cBlockHeader = cSize == 1 ?
lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
MEM_writeLE24(op, cBlockHeader);
cSize += ZSTD_blockHeaderSize;
}
}
ip += blockSize;
assert(remaining >= blockSize);
remaining -= blockSize;
@ -3552,7 +3583,7 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
assert(dstCapacity >= cSize);
dstCapacity -= cSize;
cctx->isFirstBlock = 0;
DEBUGLOG(2, "ZSTD_compress_frameChunk: adding a block of size %u",
DEBUGLOG(5, "ZSTD_compress_frameChunk: adding a block of size %u",
(unsigned)cSize);
} }
@ -3698,7 +3729,7 @@ static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
DEBUGLOG(5, "ZSTD_compressContinue_internal (blockSize=%u)", (unsigned)cctx->blockSize);
{ size_t const cSize = frame ?
ZSTD_compress_frameChunk (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize, 0 /* frame */, 0);
ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize, 0 /* frame */);
FORWARD_IF_ERROR(cSize, "%s", frame ? "ZSTD_compress_frameChunk failed" : "ZSTD_compressBlock_internal failed");
cctx->consumedSrcSize += srcSize;
cctx->producedCSize += (cSize + fhSize);

0
lib/obj/conf_2c4cce56e07d576a865fce347f466405/dynamic/libzstd.1.4.6.dylib.ld_Ak6QYf
View File

1
tests/fuzz/zstd_helpers.c
View File

@ -94,6 +94,7 @@ void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer
setRand(cctx, ZSTD_c_forceMaxWindow, 0, 1, producer);
setRand(cctx, ZSTD_c_literalCompressionMode, 0, 2, producer);
setRand(cctx, ZSTD_c_forceAttachDict, 0, 2, producer);
setRand(cctx, ZSTD_c_splitBlocks, 0, 1, producer);
if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
setRand(cctx, ZSTD_c_srcSizeHint, ZSTD_SRCSIZEHINT_MIN, 2 * srcSize, producer);
}

9
tests/fuzzer.c
View File

@ -1544,6 +1544,15 @@ static int basicUnitTests(U32 const seed, double compressibility)
ZSTD_freeCCtx(cctx);
}
DISPLAYLEVEL(3, "test%3i : compress with block splitting : ", testNb++)
{ ZSTD_CCtx* cctx = ZSTD_createCCtx();
CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_splitBlocks, 1) );
cSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
CHECK(cSize);
ZSTD_freeCCtx(cctx);
}
DISPLAYLEVEL(3, "OK \n");
DISPLAYLEVEL(3, "test%3i : compress -T2 with/without literals compression : ", testNb++)
{ ZSTD_CCtx* cctx = ZSTD_createCCtx();
size_t cSize1, cSize2;