ddidderr/zstd-rs
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code simplification (but reduce decompression speed ...)

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This commit is contained in:
Yann Collet
2016-03-21 13:24:16 +01:00
parent 5c71491a46
commit b0aec17a90
5 changed files with 113 additions and 128 deletions
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lib/zstd_compress.c
+24 -61
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@@ -191,7 +191,7 @@ static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
const size_t tableSpace = (contentSize + hSize + h3Size) * sizeof(U32);
/* Check if workSpace is large enough, alloc a new one if needed */
{ size_t const optSpace = ((1<<MLbits) + (1<<LLbits) + (1<<Offbits) + (1<<Litbits))*sizeof(U32)
{ size_t const optSpace = ((1<<MLbits) + (MaxLL+1) + (1<<Offbits) + (1<<Litbits))*sizeof(U32)
+ (ZSTD_OPT_NUM+1)*(sizeof(ZSTD_match_t) + sizeof(ZSTD_optimal_t));
size_t const neededSpace = tableSpace + (256*sizeof(U32)) /* huffTable */ + tokenSpace
+ ((params.strategy == ZSTD_btopt) ? optSpace : 0);
@@ -230,7 +230,7 @@ static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
if (params.strategy == ZSTD_btopt) {
zc->seqStore.litFreq = (U32*)((void*)(zc->seqStore.dumpsStart + maxNbSeq));
zc->seqStore.litLengthFreq = zc->seqStore.litFreq + (1<<Litbits);
zc->seqStore.matchLengthFreq = zc->seqStore.litLengthFreq + (1<<LLbits);
zc->seqStore.matchLengthFreq = zc->seqStore.litLengthFreq + (MaxLL+1);
zc->seqStore.offCodeFreq = zc->seqStore.matchLengthFreq + (1<<MLbits);
zc->seqStore.matchTable = (ZSTD_match_t*)((void*)(zc->seqStore.offCodeFreq + (1<<Offbits)));
zc->seqStore.priceTable = (ZSTD_optimal_t*)((void*)(zc->seqStore.matchTable + ZSTD_OPT_NUM+1));
@@ -585,7 +585,7 @@ size_t ZSTD_compressSequences(ZSTD_CCtx* zc,
FSE_CTable* CTable_OffsetBits = zc->offcodeCTable;
FSE_CTable* CTable_MatchLength = zc->matchlengthCTable;
U32 LLtype, Offtype, MLtype; /* compressed, raw or rle */
const U16* const llTable = seqStorePtr->litLengthStart;
U16* const llTable = seqStorePtr->litLengthStart;
const BYTE* const mlTable = seqStorePtr->matchLengthStart;
const U32* const offsetTable = seqStorePtr->offsetStart;
const U32* const offsetTableEnd = seqStorePtr->offset;
@@ -636,26 +636,24 @@ size_t ZSTD_compressSequences(ZSTD_CCtx* zc,
#define MAX_SEQ_FOR_STATIC_FSE 1000
/* LL codes */
static const BYTE llCode[64] = { 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 16, 17, 17, 18, 18, 19, 19,
20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24 };
static const BYTE deltaCode = 18;
{ size_t i;
{ static const BYTE LL_Code[64] = { 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 16, 17, 17, 18, 18, 19, 19,
20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24 };
const BYTE deltaCode = 19;
size_t i;
for (i=0; i<nbSeq; i++) {
U32 ll = llTable[i];
if (llTable[i] == 65535) ll = seqStorePtr->litLengthLong;
llCodeTable[i] = (ll>63) ? ZSTD_highbit(ll) + deltaCode : llCode[ll];
if (llTable[i] == 65535) { ll = seqStorePtr->litLengthLong; llTable[i] = (U16)ll; }
llCodeTable[i] = (ll>63) ? ZSTD_highbit(ll) + deltaCode : LL_Code[ll];
} }
/* CTable for Literal Lengths */
#if 1
{ U32 max = 35;
{ U32 max = MaxLL;
size_t const mostFrequent = FSE_countFast(count, &max, llCodeTable, nbSeq);
if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
*op++ = llCodeTable[0];
@@ -663,14 +661,8 @@ static const BYTE deltaCode = 18;
LLtype = FSE_ENCODING_RLE;
} else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
LLtype = FSE_ENCODING_STATIC;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LLbits-1)))) {
static const S16 LL_defaultNorm[36] = { 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 1, 1, 1, 1,
1, 1, 1, 1 };
static const U32 LL_defaultNormLog = 6;
FSE_buildCTable(CTable_LitLength, LL_defaultNorm, 35, LL_defaultNormLog);
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LL_defaultNormLog-1)))) {
FSE_buildCTable(CTable_LitLength, LL_defaultNorm, MaxLL, LL_defaultNormLog);
LLtype = FSE_ENCODING_RAW;
} else {
size_t NCountSize;
@@ -684,31 +676,6 @@ static const BYTE deltaCode = 18;
FSE_buildCTable(CTable_LitLength, norm, max, tableLog);
LLtype = FSE_ENCODING_DYNAMIC;
}}
#else
{ U32 max = MaxLL;
size_t const mostFrequent = FSE_countFast(count, &max, llTable, nbSeq);
if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
*op++ = llTable[0];
FSE_buildCTable_rle(CTable_LitLength, (BYTE)max);
LLtype = FSE_ENCODING_RLE;
} else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
LLtype = FSE_ENCODING_STATIC;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LLbits-1)))) {
FSE_buildCTable_raw(CTable_LitLength, LLbits);
LLtype = FSE_ENCODING_RAW;
} else {
size_t NCountSize;
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(LLFSELog, nbSeq, max);
if (count[llTable[nbSeq-1]]>1) { count[llTable[nbSeq-1]]--; nbSeq_1--; }
FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max);
NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return ERROR(GENERIC);
op += NCountSize;
FSE_buildCTable(CTable_LitLength, norm, max, tableLog);
LLtype = FSE_ENCODING_DYNAMIC;
}}
#endif // 0
/* Offset codes */
{ size_t i; for (i=0; i<nbSeq; i++) offCodeTable[i] = offsetTable[i] ? (BYTE)ZSTD_highbit(offsetTable[i]) + 1 : 0; }
@@ -778,14 +745,9 @@ static const BYTE deltaCode = 18;
FSE_initCState2(&stateOffsetBits, CTable_OffsetBits, offCodeTable[nbSeq-1]);
FSE_initCState2(&stateLitLength, CTable_LitLength, llCodeTable[nbSeq-1]);
BIT_addBits(&blockStream, offsetTable[nbSeq-1], offCodeTable[nbSeq-1] ? (offCodeTable[nbSeq-1]-1) : 0);
BIT_addBits(&blockStream, llTable[nbSeq-1], LL_bits[llCodeTable[nbSeq-1]]);
BIT_flushBits(&blockStream);
static const U32 llBits[36] = { 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 2, 2, 3, 3,
4, 6, 7, 8, 9,10,11,12,
13,14,15,16 };
{ size_t n;
for (n=nbSeq-2; n<nbSeq; n--) { /* intentional underflow */
const BYTE mlCode = mlTable[n];
@@ -800,7 +762,7 @@ static const U32 llBits[36] = { 0, 0, 0, 0, 0, 0, 0, 0,
if (MEM_32bits()) BIT_flushBits(&blockStream); /* 7 */
//BIT_flushBits(&blockStream); /* 7 */ /* 7 */
BIT_addBits(&blockStream, offset, nbBits); /* 31 */ /* 61 */ /* 24 bits max in 32-bits mode */
BIT_addBits(&blockStream, llTable[n], llBits[LLCode]);
BIT_addBits(&blockStream, llTable[n], LL_bits[LLCode]);
BIT_flushBits(&blockStream); /* 7 */ /* 7 */
} }
#else
@@ -856,10 +818,11 @@ MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const B
{
#if 0 /* for debug */
static const BYTE* g_start = NULL;
const U32 pos = (U32)(literals - g_start);
if (g_start==NULL) g_start = literals;
//if (literals - g_start == 8695)
if ((pos > 198618400) && (pos < 198618500))
printf("pos %6u : %3u literals & match %3u bytes at distance %6u \n",
(U32)(literals - g_start), (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
pos, (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
#endif
#if ZSTD_OPT_DEBUG == 3
if (offsetCode == 0) seqStorePtr->realRepSum++;
@@ -2278,7 +2241,7 @@ size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* zc,
ZSTD_validateParams(&params);
{ size_t const errorCode = ZSTD_resetCCtx_advanced(zc, params);
if (ZSTD_isError(errorCode)) return errorCode; }
if (ZSTD_isError(errorCode)) return errorCode; }
/* Write Frame Header into ctx headerBuffer */
MEM_writeLE32(zc->headerBuffer, ZSTD_MAGICNUMBER);