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[libzstd] Increase granularity of FSECTable repeat mode

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This commit is contained in:
Nick Terrell 2017-07-13 12:45:39 -07:00
parent d985319337
commit 830ef4152a
3 changed files with 33 additions and 9 deletions
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5
lib/common/fse.h
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@ -384,6 +384,11 @@ size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, FSE_DTable* workSpace, unsigned maxLog);
/**< same as FSE_decompress(), using an externally allocated `workSpace` produced with `FSE_DTABLE_SIZE_U32(maxLog)` */
typedef enum {
FSE_repeat_none, /**< Cannot use the previous table */
FSE_repeat_check, /**< Can use the previous table but it must be checked */
FSE_repeat_valid /**< Can use the previous table and it is asumed to be valid */
} FSE_repeat;
/* *****************************************
* FSE symbol compression API

6
lib/common/zstd_internal.h
View File

@ -271,13 +271,15 @@ typedef struct {
} seqStore_t;
typedef struct {
HUF_repeat hufCTable_repeatMode;
U32 hufCTable[HUF_CTABLE_SIZE_U32(255)];
U32 fseCTables_ready;
FSE_CTable offcodeCTable[FSE_CTABLE_SIZE_U32(OffFSELog, MaxOff)];
FSE_CTable matchlengthCTable[FSE_CTABLE_SIZE_U32(MLFSELog, MaxML)];
FSE_CTable litlengthCTable[FSE_CTABLE_SIZE_U32(LLFSELog, MaxLL)];
U32 workspace[HUF_WORKSPACE_SIZE_U32];
HUF_repeat hufCTable_repeatMode;
FSE_repeat offcode_repeatMode;
FSE_repeat matchlength_repeatMode;
FSE_repeat litlength_repeatMode;
} ZSTD_entropyCTables_t;
const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx);

31
lib/compress/zstd_compress.c
View File

@ -616,8 +616,10 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
if (crp == ZSTDcrp_continue) {
if (ZSTD_equivalentParams(params.cParams, zc->appliedParams.cParams)) {
DEBUGLOG(5, "ZSTD_equivalentParams()==1");
zc->entropy->fseCTables_ready = 0;
zc->entropy->hufCTable_repeatMode = HUF_repeat_none;
zc->entropy->offcode_repeatMode = FSE_repeat_none;
zc->entropy->matchlength_repeatMode = FSE_repeat_none;
zc->entropy->litlength_repeatMode = FSE_repeat_none;
return ZSTD_continueCCtx(zc, params, pledgedSrcSize);
} }
@ -681,8 +683,10 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
zc->stage = ZSTDcs_init;
zc->dictID = 0;
zc->loadedDictEnd = 0;
zc->entropy->fseCTables_ready = 0;
zc->entropy->hufCTable_repeatMode = HUF_repeat_none;
zc->entropy->offcode_repeatMode = FSE_repeat_none;
zc->entropy->matchlength_repeatMode = FSE_repeat_none;
zc->entropy->litlength_repeatMode = FSE_repeat_none;
zc->nextToUpdate = 1;
zc->nextSrc = NULL;
zc->base = NULL;
@ -1067,11 +1071,13 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
*op++ = llCodeTable[0];
FSE_buildCTable_rle(CTable_LitLength, (BYTE)max);
LLtype = set_rle;
} else if ((zc->entropy->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
zc->entropy->litlength_repeatMode = FSE_repeat_check;
} else if ((zc->entropy->litlength_repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
LLtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LL_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_LitLength, LL_defaultNorm, MaxLL, LL_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
LLtype = set_basic;
zc->entropy->litlength_repeatMode = FSE_repeat_valid;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(LLFSELog, nbSeq, max);
@ -1082,6 +1088,7 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
op += NCountSize; }
FSE_buildCTable_wksp(CTable_LitLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
LLtype = set_compressed;
zc->entropy->litlength_repeatMode = FSE_repeat_check;
} }
/* CTable for Offsets */
@ -1091,11 +1098,13 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
*op++ = ofCodeTable[0];
FSE_buildCTable_rle(CTable_OffsetBits, (BYTE)max);
Offtype = set_rle;
} else if ((zc->entropy->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
zc->entropy->offcode_repeatMode = FSE_repeat_check;
} else if ((zc->entropy->offcode_repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
Offtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (OF_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_OffsetBits, OF_defaultNorm, MaxOff, OF_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
Offtype = set_basic;
zc->entropy->offcode_repeatMode = FSE_repeat_valid;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(OffFSELog, nbSeq, max);
@ -1106,6 +1115,7 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
op += NCountSize; }
FSE_buildCTable_wksp(CTable_OffsetBits, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
Offtype = set_compressed;
zc->entropy->offcode_repeatMode = FSE_repeat_check;
} }
/* CTable for MatchLengths */
@ -1115,11 +1125,13 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
*op++ = *mlCodeTable;
FSE_buildCTable_rle(CTable_MatchLength, (BYTE)max);
MLtype = set_rle;
} else if ((zc->entropy->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
zc->entropy->matchlength_repeatMode = FSE_repeat_check;
} else if ((zc->entropy->matchlength_repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
MLtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (ML_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_MatchLength, ML_defaultNorm, MaxML, ML_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
MLtype = set_basic;
zc->entropy->matchlength_repeatMode = FSE_repeat_valid;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(MLFSELog, nbSeq, max);
@ -1130,10 +1142,10 @@ MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
op += NCountSize; }
FSE_buildCTable_wksp(CTable_MatchLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
MLtype = set_compressed;
zc->entropy->matchlength_repeatMode = FSE_repeat_check;
} }
*seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
zc->entropy->fseCTables_ready = 0;
/* Encoding Sequences */
{ BIT_CStream_t blockStream;
@ -1213,6 +1225,9 @@ _check_compressibility:
size_t const maxCSize = srcSize - minGain;
if ((size_t)(op-ostart) >= maxCSize) {
zc->entropy->hufCTable_repeatMode = HUF_repeat_none;
zc->entropy->offcode_repeatMode = FSE_repeat_none;
zc->entropy->matchlength_repeatMode = FSE_repeat_none;
zc->entropy->litlength_repeatMode = FSE_repeat_none;
return 0;
} }
@ -3124,8 +3139,10 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_CCtx* cctx, const void* dict, size_t
if (cctx->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
} }
cctx->entropy->fseCTables_ready = 1;
cctx->entropy->hufCTable_repeatMode = HUF_repeat_valid;
cctx->entropy->offcode_repeatMode = FSE_repeat_valid;
cctx->entropy->matchlength_repeatMode = FSE_repeat_valid;
cctx->entropy->litlength_repeatMode = FSE_repeat_valid;
return ZSTD_loadDictionaryContent(cctx, dictPtr, dictContentSize);
}
}