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zstd_opt: ensure sufficient_len < ZSTD_OPT_NUM to simplify some tests

dev
Yann Collet 2017-11-08 11:05:32 -08:00
parent ee441d5d2b
commit 4191efa993
3 changed files with 96 additions and 82 deletions
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40
lib/common/zstd_internal.h
View File

@ -138,28 +138,40 @@ typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingTy
#define LLFSELog 9
#define OffFSELog 8
static const U32 LL_bits[MaxLL+1] = { 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,
static const U32 LL_bits[MaxLL+1] = { 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 };
static const S16 LL_defaultNorm[MaxLL+1] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1,
static const S16 LL_defaultNorm[MaxLL+1] = { 4, 3, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2,
2, 3, 2, 1, 1, 1, 1, 1,
-1,-1,-1,-1 };
#define LL_DEFAULTNORMLOG 6 /* for static allocation */
static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
static const U32 ML_bits[MaxML+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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, 4, 5, 7, 8, 9,10,11,
static const U32 ML_bits[MaxML+1] = { 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
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, 4, 5, 7, 8, 9,10,11,
12,13,14,15,16 };
static const S16 ML_defaultNorm[MaxML+1] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,
static const S16 ML_defaultNorm[MaxML+1] = { 1, 4, 3, 2, 2, 2, 2, 2,
2, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1,-1,-1,
-1,-1,-1,-1,-1 };
#define ML_DEFAULTNORMLOG 6 /* for static allocation */
static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
static const S16 OF_defaultNorm[DefaultMaxOff+1] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1 };
static const S16 OF_defaultNorm[DefaultMaxOff+1] = { 1, 1, 1, 1, 1, 1, 2, 2,
2, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
-1,-1,-1,-1,-1 };
#define OF_DEFAULTNORMLOG 5 /* for static allocation */
static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
@ -266,8 +278,8 @@ typedef struct {
} blockProperties_t;
/*! ZSTD_getcBlockSize() :
* Provides the size of compressed block from block header `src`
* Used by: decompress, fullbench (does not get its definition from here) */
* Provides the size of compressed block from block header `src` */
/* Used by: decompress, fullbench (does not get its definition from here) */
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
blockProperties_t* bpPtr);

25
lib/compress/zstd_compress_internal.h
View File

@ -79,18 +79,19 @@ typedef struct {
ZSTD_match_t* matchTable;
ZSTD_optimal_t* priceTable;
U32 matchLengthSum;
U32 matchSum;
U32 litLengthSum;
U32 litSum;
U32 offCodeSum;
U32 log2matchLengthSum;
U32 log2matchSum;
U32 log2litLengthSum;
U32 log2litSum;
U32 log2offCodeSum;
U32 factor;
U32 staticPrices;
U32 litSum; /* nb of literals */
U32 litLengthSum; /* nb of litLength codes */
U32 matchLengthSum; /* nb of matchLength codes */
U32 matchSum; /* one argument to calculate `factor` */
U32 offCodeSum; /* nb of offset codes */
/* begin updated by ZSTD_setLog2Prices */
U32 log2litSum; /* pow2 to compare log2(litfreq) to */
U32 log2litLengthSum; /* pow2 to compare log2(llfreq) to */
U32 log2matchLengthSum; /* pow2 to compare log2(mlfreq) to */
U32 log2offCodeSum; /* pow2 to compare log2(offreq) to */
U32 factor; /* added to calculate ZSTD_getPrice() (but why?) */
/* end : updated by ZSTD_setLog2Prices */
U32 staticPrices; /* ? do not update statistics ? */
U32 cachedPrice;
U32 cachedLitLength;
const BYTE* cachedLiterals;

99
lib/compress/zstd_opt.c
View File

@ -13,8 +13,8 @@
#include "zstd_lazy.h" /* ZSTD_updateTree, ZSTD_updateTree_extDict */
#define ZSTD_LITFREQ_ADD 2
#define ZSTD_FREQ_DIV 4
#define ZSTD_LITFREQ_ADD 2 /* sort of scaling factor for litSum and litFreq (why the need ?), but also used for matchSum ? */
#define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */
#define ZSTD_MAX_PRICE (1<<30)
/*-*************************************
@ -22,12 +22,12 @@
***************************************/
static void ZSTD_setLog2Prices(optState_t* optPtr)
{
optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1);
optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1);
optPtr->factor = 1 + ((optPtr->litSum>>5) / optPtr->litLengthSum)
+ ((optPtr->litSum<<1) / (optPtr->litSum + optPtr->matchSum));
+ ((optPtr->litSum<<1) / (optPtr->litSum + optPtr->matchSum)); /* => {0,1}, == (optPtr->matchSum <= optPtr->litSum) */
}
@ -46,47 +46,45 @@ static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSiz
optPtr->litFreq[u] = 0;
for (u=0; u<srcSize; u++)
optPtr->litFreq[src[u]]++;
optPtr->litSum = 0;
optPtr->litLengthSum = MaxLL+1;
optPtr->matchLengthSum = MaxML+1;
optPtr->offCodeSum = (MaxOff+1);
optPtr->matchSum = (ZSTD_LITFREQ_ADD << Litbits);
for (u=0; u<=MaxLit; u++) {
optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> ZSTD_FREQ_DIV);
optPtr->litSum += optPtr->litFreq[u];
}
for (u=0; u<=MaxLL; u++)
optPtr->litLengthFreq[u] = 1;
optPtr->litLengthSum = MaxLL+1;
for (u=0; u<=MaxML; u++)
optPtr->matchLengthFreq[u] = 1;
optPtr->matchLengthSum = MaxML+1;
optPtr->matchSum = (ZSTD_LITFREQ_ADD << Litbits);
for (u=0; u<=MaxOff; u++)
optPtr->offCodeFreq[u] = 1;
optPtr->offCodeSum = (MaxOff+1);
} else {
unsigned u;
optPtr->matchLengthSum = 0;
optPtr->litLengthSum = 0;
optPtr->offCodeSum = 0;
optPtr->matchSum = 0;
optPtr->litSum = 0;
optPtr->litSum = 0;
for (u=0; u<=MaxLit; u++) {
optPtr->litFreq[u] = 1 + (optPtr->litFreq[u]>>(ZSTD_FREQ_DIV+1));
optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1));
optPtr->litSum += optPtr->litFreq[u];
}
optPtr->litLengthSum = 0;
for (u=0; u<=MaxLL; u++) {
optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1));
optPtr->litLengthSum += optPtr->litLengthFreq[u];
}
optPtr->matchLengthSum = 0;
optPtr->matchSum = 0;
for (u=0; u<=MaxML; u++) {
optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
optPtr->matchSum += optPtr->matchLengthFreq[u] * (u + 3);
}
optPtr->matchSum *= ZSTD_LITFREQ_ADD;
optPtr->offCodeSum = 0;
for (u=0; u<=MaxOff; u++) {
optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
optPtr->offCodeSum += optPtr->offCodeFreq[u];
@ -99,24 +97,26 @@ static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSiz
static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* literals)
{
U32 price, u;
U32 price;
if (optPtr->staticPrices)
return ZSTD_highbit32((U32)litLength+1) + (litLength*6);
return ZSTD_highbit32((U32)litLength+1) + (litLength*6); /* 6 bit per literal - no real estimation */
if (litLength == 0)
return optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[0]+1);
/* literals */
if (optPtr->cachedLiterals == literals) {
U32 u;
U32 const additional = litLength - optPtr->cachedLitLength;
const BYTE* literals2 = optPtr->cachedLiterals + optPtr->cachedLitLength;
const BYTE* const literals2 = optPtr->cachedLiterals + optPtr->cachedLitLength;
price = optPtr->cachedPrice + additional * optPtr->log2litSum;
for (u=0; u < additional; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals2[u]]+1);
optPtr->cachedPrice = price;
optPtr->cachedLitLength = litLength;
} else {
U32 u;
price = litLength * optPtr->log2litSum;
for (u=0; u < litLength; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
@ -129,8 +129,8 @@ static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* l
}
/* literal Length */
{ const BYTE LL_deltaCode = 19;
const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
{ BYTE const LL_deltaCode = 19;
BYTE const llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
price += LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
}
@ -148,11 +148,11 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_getPrice(optState_t* optPtr, U32 litLength, const
return ZSTD_getLiteralPrice(optPtr, litLength, literals) + ZSTD_highbit32((U32)matchLength+1) + 16 + offCode;
price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
if (!ultra && offCode >= 20) price += (offCode-19)*2;
if (!ultra && offCode >= 20) price += (offCode-19)*2; /* handicap for long matches, to favor decompression speed */
/* match Length */
{ const BYTE ML_deltaCode = 36;
const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
{ BYTE const ML_deltaCode = 36;
BYTE const mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
}
@ -193,6 +193,7 @@ static void ZSTD_updatePrice(optState_t* optPtr, U32 litLength, const BYTE* lite
}
/* update opt[pos] and last_pos */
#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \
{ \
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
@ -220,15 +221,14 @@ static U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
/* Update hashTable3 up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
static
U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
{
U32* const hashTable3 = zc->hashTable3;
U32 const hashLog3 = zc->hashLog3;
const BYTE* const base = zc->base;
U32 idx = zc->nextToUpdate3;
const U32 target = zc->nextToUpdate3 = (U32)(ip - base);
const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3);
U32 const target = zc->nextToUpdate3 = (U32)(ip - base);
size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
while(idx < target) {
hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
@ -427,15 +427,14 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
const BYTE* const base = ctx->base;
const BYTE* const prefixStart = base + ctx->dictLimit;
const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
const U32 sufficient_len = ctx->appliedParams.cParams.targetLength;
const U32 mls = ctx->appliedParams.cParams.searchLength;
const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
U32 const maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
U32 const sufficient_len = MIN(ctx->appliedParams.cParams.targetLength, ZSTD_OPT_NUM -1);
U32 const mls = ctx->appliedParams.cParams.searchLength;
U32 const minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
ZSTD_optimal_t* opt = optStatePtr->priceTable;
ZSTD_match_t* matches = optStatePtr->matchTable;
const BYTE* inr;
U32 offset, rep[ZSTD_REP_NUM];
ZSTD_optimal_t* const opt = optStatePtr->priceTable;
ZSTD_match_t* const matches = optStatePtr->matchTable;
U32 rep[ZSTD_REP_NUM];
/* init */
ctx->nextToUpdate3 = ctx->nextToUpdate;
@ -446,19 +445,20 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
/* Match Loop */
while (ip < ilimit) {
U32 cur, match_num, last_pos, litlen, price;
U32 u, mlen, best_mlen, best_off, litLength;
U32 u, mlen, best_mlen, best_off, litLength, offset;
memset(opt, 0, sizeof(ZSTD_optimal_t));
last_pos = 0;
litlen = (U32)(ip - anchor);
/* check repCode */
{ U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
for (i=(ip == anchor); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
if ( (repCur > 0) && (repCur < (S32)(ip-prefixStart))
for (i = (ip==anchor); i < last_i; i++) {
S32 const repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
if ( (repCur > 0)
&& (repCur < (S32)(ip-prefixStart)) /* only check within current mem segment */
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) {
mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repCur, iend) + minMatch;
if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
if (mlen > sufficient_len) {
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
@ -475,7 +475,7 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
if (!last_pos && !match_num) { ip++; continue; }
if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
if (match_num && (matches[match_num-1].len > sufficient_len)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
cur = 0;
@ -504,7 +504,7 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
/* check further positions */
for (cur = 1; cur <= last_pos; cur++) {
inr = ip + cur;
const BYTE* const inr = ip + cur;
if (opt[cur-1].mlen == 1) {
litlen = opt[cur-1].litlen + 1;
@ -518,7 +518,7 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
SET_PRICE(cur, 1, 0, litlen, price); /* note : macro modifies last_pos */
if (cur == last_pos) break;
@ -572,7 +572,7 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
SET_PRICE(cur + mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
@ -604,7 +604,7 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */
mlen++;
} } }
@ -657,7 +657,8 @@ _storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
anchor = ip = ip + mlen;
} } /* for (cur=0; cur < last_pos; ) */
}
} /* for (cur=0; cur < last_pos; ) */
/* Save reps for next block */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; }