VOL-1967 move api-server to separate repository
Change-Id: I21b85be74205805be15f8a85e53a903d16785671
diff --git a/vendor/github.com/DataDog/zstd/zstd_opt.c b/vendor/github.com/DataDog/zstd/zstd_opt.c
index f63f0c5..e32e542 100644
--- a/vendor/github.com/DataDog/zstd/zstd_opt.c
+++ b/vendor/github.com/DataDog/zstd/zstd_opt.c
@@ -9,139 +9,259 @@
*/
#include "zstd_compress_internal.h"
+#include "hist.h"
#include "zstd_opt.h"
-#define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats. Also used for matchSum (?) */
+#define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats */
#define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */
#define ZSTD_MAX_PRICE (1<<30)
+#define ZSTD_PREDEF_THRESHOLD 1024 /* if srcSize < ZSTD_PREDEF_THRESHOLD, symbols' cost is assumed static, directly determined by pre-defined distributions */
+
/*-*************************************
* Price functions for optimal parser
***************************************/
-static void ZSTD_setLog2Prices(optState_t* optPtr)
+
+#if 0 /* approximation at bit level */
+# define BITCOST_ACCURACY 0
+# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+# define WEIGHT(stat) ((void)opt, ZSTD_bitWeight(stat))
+#elif 0 /* fractional bit accuracy */
+# define BITCOST_ACCURACY 8
+# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+# define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat))
+#else /* opt==approx, ultra==accurate */
+# define BITCOST_ACCURACY 8
+# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+# define WEIGHT(stat,opt) (opt ? ZSTD_fracWeight(stat) : ZSTD_bitWeight(stat))
+#endif
+
+MEM_STATIC U32 ZSTD_bitWeight(U32 stat)
{
- 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);
+ return (ZSTD_highbit32(stat+1) * BITCOST_MULTIPLIER);
+}
+
+MEM_STATIC U32 ZSTD_fracWeight(U32 rawStat)
+{
+ U32 const stat = rawStat + 1;
+ U32 const hb = ZSTD_highbit32(stat);
+ U32 const BWeight = hb * BITCOST_MULTIPLIER;
+ U32 const FWeight = (stat << BITCOST_ACCURACY) >> hb;
+ U32 const weight = BWeight + FWeight;
+ assert(hb + BITCOST_ACCURACY < 31);
+ return weight;
+}
+
+#if (DEBUGLEVEL>=2)
+/* debugging function,
+ * @return price in bytes as fractional value
+ * for debug messages only */
+MEM_STATIC double ZSTD_fCost(U32 price)
+{
+ return (double)price / (BITCOST_MULTIPLIER*8);
+}
+#endif
+
+static int ZSTD_compressedLiterals(optState_t const* const optPtr)
+{
+ return optPtr->literalCompressionMode != ZSTD_lcm_uncompressed;
+}
+
+static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel)
+{
+ if (ZSTD_compressedLiterals(optPtr))
+ optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel);
+ optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel);
+ optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel);
+ optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel);
}
-static void ZSTD_rescaleFreqs(optState_t* const optPtr,
- const BYTE* const src, size_t const srcSize)
+/* ZSTD_downscaleStat() :
+ * reduce all elements in table by a factor 2^(ZSTD_FREQ_DIV+malus)
+ * return the resulting sum of elements */
+static U32 ZSTD_downscaleStat(unsigned* table, U32 lastEltIndex, int malus)
{
- optPtr->staticPrices = 0;
+ U32 s, sum=0;
+ DEBUGLOG(5, "ZSTD_downscaleStat (nbElts=%u)", (unsigned)lastEltIndex+1);
+ assert(ZSTD_FREQ_DIV+malus > 0 && ZSTD_FREQ_DIV+malus < 31);
+ for (s=0; s<lastEltIndex+1; s++) {
+ table[s] = 1 + (table[s] >> (ZSTD_FREQ_DIV+malus));
+ sum += table[s];
+ }
+ return sum;
+}
- if (optPtr->litLengthSum == 0) { /* first init */
- unsigned u;
- if (srcSize <= 1024) optPtr->staticPrices = 1;
+/* ZSTD_rescaleFreqs() :
+ * if first block (detected by optPtr->litLengthSum == 0) : init statistics
+ * take hints from dictionary if there is one
+ * or init from zero, using src for literals stats, or flat 1 for match symbols
+ * otherwise downscale existing stats, to be used as seed for next block.
+ */
+static void
+ZSTD_rescaleFreqs(optState_t* const optPtr,
+ const BYTE* const src, size_t const srcSize,
+ int const optLevel)
+{
+ int const compressedLiterals = ZSTD_compressedLiterals(optPtr);
+ DEBUGLOG(5, "ZSTD_rescaleFreqs (srcSize=%u)", (unsigned)srcSize);
+ optPtr->priceType = zop_dynamic;
- assert(optPtr->litFreq!=NULL);
- for (u=0; u<=MaxLit; u++)
- optPtr->litFreq[u] = 0;
- for (u=0; u<srcSize; u++)
- optPtr->litFreq[src[u]]++;
- optPtr->litSum = 0;
- for (u=0; u<=MaxLit; u++) {
- optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> ZSTD_FREQ_DIV);
- optPtr->litSum += optPtr->litFreq[u];
+ if (optPtr->litLengthSum == 0) { /* first block : init */
+ if (srcSize <= ZSTD_PREDEF_THRESHOLD) { /* heuristic */
+ DEBUGLOG(5, "(srcSize <= ZSTD_PREDEF_THRESHOLD) => zop_predef");
+ optPtr->priceType = zop_predef;
}
- 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;
- for (u=0; u<=MaxOff; u++)
- optPtr->offCodeFreq[u] = 1;
- optPtr->offCodeSum = (MaxOff+1);
+ assert(optPtr->symbolCosts != NULL);
+ if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) {
+ /* huffman table presumed generated by dictionary */
+ optPtr->priceType = zop_dynamic;
- } else {
- unsigned u;
+ if (compressedLiterals) {
+ unsigned lit;
+ assert(optPtr->litFreq != NULL);
+ optPtr->litSum = 0;
+ for (lit=0; lit<=MaxLit; lit++) {
+ U32 const scaleLog = 11; /* scale to 2K */
+ U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit);
+ assert(bitCost <= scaleLog);
+ optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+ optPtr->litSum += optPtr->litFreq[lit];
+ } }
- optPtr->litSum = 0;
- for (u=0; u<=MaxLit; u++) {
- optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1));
- optPtr->litSum += optPtr->litFreq[u];
+ { unsigned ll;
+ FSE_CState_t llstate;
+ FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable);
+ optPtr->litLengthSum = 0;
+ for (ll=0; ll<=MaxLL; ll++) {
+ U32 const scaleLog = 10; /* scale to 1K */
+ U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll);
+ assert(bitCost < scaleLog);
+ optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+ optPtr->litLengthSum += optPtr->litLengthFreq[ll];
+ } }
+
+ { unsigned ml;
+ FSE_CState_t mlstate;
+ FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
+ optPtr->matchLengthSum = 0;
+ for (ml=0; ml<=MaxML; ml++) {
+ U32 const scaleLog = 10;
+ U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml);
+ assert(bitCost < scaleLog);
+ optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+ optPtr->matchLengthSum += optPtr->matchLengthFreq[ml];
+ } }
+
+ { unsigned of;
+ FSE_CState_t ofstate;
+ FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable);
+ optPtr->offCodeSum = 0;
+ for (of=0; of<=MaxOff; of++) {
+ U32 const scaleLog = 10;
+ U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of);
+ assert(bitCost < scaleLog);
+ optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+ optPtr->offCodeSum += optPtr->offCodeFreq[of];
+ } }
+
+ } else { /* not a dictionary */
+
+ assert(optPtr->litFreq != NULL);
+ if (compressedLiterals) {
+ unsigned lit = MaxLit;
+ HIST_count_simple(optPtr->litFreq, &lit, src, srcSize); /* use raw first block to init statistics */
+ optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
+ }
+
+ { unsigned ll;
+ for (ll=0; ll<=MaxLL; ll++)
+ optPtr->litLengthFreq[ll] = 1;
+ }
+ optPtr->litLengthSum = MaxLL+1;
+
+ { unsigned ml;
+ for (ml=0; ml<=MaxML; ml++)
+ optPtr->matchLengthFreq[ml] = 1;
+ }
+ optPtr->matchLengthSum = MaxML+1;
+
+ { unsigned of;
+ for (of=0; of<=MaxOff; of++)
+ optPtr->offCodeFreq[of] = 1;
+ }
+ optPtr->offCodeSum = MaxOff+1;
+
}
- 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;
- for (u=0; u<=MaxML; u++) {
- optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
- optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
- }
- optPtr->offCodeSum = 0;
- for (u=0; u<=MaxOff; u++) {
- optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
- optPtr->offCodeSum += optPtr->offCodeFreq[u];
- }
+
+ } else { /* new block : re-use previous statistics, scaled down */
+
+ if (compressedLiterals)
+ optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
+ optPtr->litLengthSum = ZSTD_downscaleStat(optPtr->litLengthFreq, MaxLL, 0);
+ optPtr->matchLengthSum = ZSTD_downscaleStat(optPtr->matchLengthFreq, MaxML, 0);
+ optPtr->offCodeSum = ZSTD_downscaleStat(optPtr->offCodeFreq, MaxOff, 0);
}
- ZSTD_setLog2Prices(optPtr);
+ ZSTD_setBasePrices(optPtr, optLevel);
}
-
/* ZSTD_rawLiteralsCost() :
- * cost of literals (only) in given segment (which length can be null)
- * does not include cost of literalLength symbol */
+ * price of literals (only) in specified segment (which length can be 0).
+ * does not include price of literalLength symbol */
static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
- const optState_t* const optPtr)
+ const optState_t* const optPtr,
+ int optLevel)
{
- if (optPtr->staticPrices) return (litLength*6); /* 6 bit per literal - no statistic used */
if (litLength == 0) return 0;
- /* literals */
- { U32 u;
- U32 cost = litLength * optPtr->log2litSum;
- for (u=0; u < litLength; u++)
- cost -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
- return cost;
- }
-}
+ if (!ZSTD_compressedLiterals(optPtr))
+ return (litLength << 3) * BITCOST_MULTIPLIER; /* Uncompressed - 8 bytes per literal. */
-/* ZSTD_litLengthPrice() :
- * cost of literalLength symbol */
-static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr)
-{
- if (optPtr->staticPrices) return ZSTD_highbit32((U32)litLength+1);
+ if (optPtr->priceType == zop_predef)
+ return (litLength*6) * BITCOST_MULTIPLIER; /* 6 bit per literal - no statistic used */
- /* literal Length */
- { U32 const llCode = ZSTD_LLcode(litLength);
- U32 const price = LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
+ /* dynamic statistics */
+ { U32 price = litLength * optPtr->litSumBasePrice;
+ U32 u;
+ for (u=0; u < litLength; u++) {
+ assert(WEIGHT(optPtr->litFreq[literals[u]], optLevel) <= optPtr->litSumBasePrice); /* literal cost should never be negative */
+ price -= WEIGHT(optPtr->litFreq[literals[u]], optLevel);
+ }
return price;
}
}
/* ZSTD_litLengthPrice() :
- * cost of the literal part of a sequence,
- * including literals themselves, and literalLength symbol */
-static U32 ZSTD_fullLiteralsCost(const BYTE* const literals, U32 const litLength,
- const optState_t* const optPtr)
+ * cost of literalLength symbol */
+static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr, int optLevel)
{
- return ZSTD_rawLiteralsCost(literals, litLength, optPtr)
- + ZSTD_litLengthPrice(litLength, optPtr);
+ if (optPtr->priceType == zop_predef) return WEIGHT(litLength, optLevel);
+
+ /* dynamic statistics */
+ { U32 const llCode = ZSTD_LLcode(litLength);
+ return (LL_bits[llCode] * BITCOST_MULTIPLIER)
+ + optPtr->litLengthSumBasePrice
+ - WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
+ }
}
/* ZSTD_litLengthContribution() :
* @return ( cost(litlength) - cost(0) )
* this value can then be added to rawLiteralsCost()
* to provide a cost which is directly comparable to a match ending at same position */
-static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr)
+static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr, int optLevel)
{
- if (optPtr->staticPrices) return ZSTD_highbit32(litLength+1);
+ if (optPtr->priceType >= zop_predef) return (int)WEIGHT(litLength, optLevel);
- /* literal Length */
+ /* dynamic statistics */
{ U32 const llCode = ZSTD_LLcode(litLength);
- int const contribution = LL_bits[llCode]
- + ZSTD_highbit32(optPtr->litLengthFreq[0]+1)
- - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
+ int const contribution = (int)(LL_bits[llCode] * BITCOST_MULTIPLIER)
+ + (int)WEIGHT(optPtr->litLengthFreq[0], optLevel) /* note: log2litLengthSum cancel out */
+ - (int)WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
#if 1
return contribution;
#else
@@ -155,10 +275,11 @@
* which can be compared to the ending cost of a match
* should a new match start at this position */
static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength,
- const optState_t* const optPtr)
+ const optState_t* const optPtr,
+ int optLevel)
{
- int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr)
- + ZSTD_litLengthContribution(litLength, optPtr);
+ int const contribution = (int)ZSTD_rawLiteralsCost(literals, litLength, optPtr, optLevel)
+ + ZSTD_litLengthContribution(litLength, optPtr, optLevel);
return contribution;
}
@@ -166,37 +287,45 @@
* Provides the cost of the match part (offset + matchLength) of a sequence
* Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence.
* optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */
-FORCE_INLINE_TEMPLATE U32 ZSTD_getMatchPrice(
- U32 const offset, U32 const matchLength,
- const optState_t* const optPtr,
- int const optLevel)
+FORCE_INLINE_TEMPLATE U32
+ZSTD_getMatchPrice(U32 const offset,
+ U32 const matchLength,
+ const optState_t* const optPtr,
+ int const optLevel)
{
U32 price;
U32 const offCode = ZSTD_highbit32(offset+1);
U32 const mlBase = matchLength - MINMATCH;
assert(matchLength >= MINMATCH);
- if (optPtr->staticPrices) /* fixed scheme, do not use statistics */
- return ZSTD_highbit32((U32)mlBase+1) + 16 + offCode;
+ if (optPtr->priceType == zop_predef) /* fixed scheme, do not use statistics */
+ return WEIGHT(mlBase, optLevel) + ((16 + offCode) * BITCOST_MULTIPLIER);
- price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
- if ((optLevel<2) /*static*/ && offCode >= 20) price += (offCode-19)*2; /* handicap for long distance offsets, favor decompression speed */
+ /* dynamic statistics */
+ price = (offCode * BITCOST_MULTIPLIER) + (optPtr->offCodeSumBasePrice - WEIGHT(optPtr->offCodeFreq[offCode], optLevel));
+ if ((optLevel<2) /*static*/ && offCode >= 20)
+ price += (offCode-19)*2 * BITCOST_MULTIPLIER; /* handicap for long distance offsets, favor decompression speed */
/* match Length */
{ U32 const mlCode = ZSTD_MLcode(mlBase);
- price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
+ price += (ML_bits[mlCode] * BITCOST_MULTIPLIER) + (optPtr->matchLengthSumBasePrice - WEIGHT(optPtr->matchLengthFreq[mlCode], optLevel));
}
+ price += BITCOST_MULTIPLIER / 5; /* heuristic : make matches a bit more costly to favor less sequences -> faster decompression speed */
+
DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price);
return price;
}
+/* ZSTD_updateStats() :
+ * assumption : literals + litLengtn <= iend */
static void ZSTD_updateStats(optState_t* const optPtr,
U32 litLength, const BYTE* literals,
U32 offsetCode, U32 matchLength)
{
/* literals */
- { U32 u;
+ if (ZSTD_compressedLiterals(optPtr)) {
+ U32 u;
for (u=0; u < litLength; u++)
optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
@@ -243,13 +372,15 @@
/* Update hashTable3 up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
-static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* const ip)
+static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms,
+ U32* nextToUpdate3,
+ const BYTE* const ip)
{
U32* const hashTable3 = ms->hashTable3;
U32 const hashLog3 = ms->hashLog3;
const BYTE* const base = ms->window.base;
- U32 idx = ms->nextToUpdate3;
- U32 const target = ms->nextToUpdate3 = (U32)(ip - base);
+ U32 idx = *nextToUpdate3;
+ U32 const target = (U32)(ip - base);
size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
assert(hashLog3 > 0);
@@ -258,6 +389,7 @@
idx++;
}
+ *nextToUpdate3 = target;
return hashTable3[hash3];
}
@@ -269,10 +401,11 @@
* ip : assumed <= iend-8 .
* @return : nb of positions added */
static U32 ZSTD_insertBt1(
- ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+ ZSTD_matchState_t* ms,
const BYTE* const ip, const BYTE* const iend,
- U32 const mls, U32 const extDict)
+ U32 const mls, const int extDict)
{
+ const ZSTD_compressionParameters* const cParams = &ms->cParams;
U32* const hashTable = ms->hashTable;
U32 const hashLog = cParams->hashLog;
size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
@@ -308,7 +441,8 @@
assert(ip <= iend-8); /* required for h calculation */
hashTable[h] = current; /* Update Hash Table */
- while (nbCompares-- && (matchIndex > windowLow)) {
+ assert(windowLow > 0);
+ while (nbCompares-- && (matchIndex >= windowLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
assert(matchIndex < current);
@@ -334,8 +468,8 @@
}
#endif
- if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
- assert(matchIndex+matchLength >= dictLimit); /* might be wrong if extDict is incorrectly set to 0 */
+ if (!extDict || (matchIndex+matchLength >= dictLimit)) {
+ assert(matchIndex+matchLength >= dictLimit); /* might be wrong if actually extDict */
match = base + matchIndex;
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
} else {
@@ -372,43 +506,53 @@
} }
*smallerPtr = *largerPtr = 0;
- if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */
- assert(matchEndIdx > current + 8);
- return matchEndIdx - (current + 8);
+ { U32 positions = 0;
+ if (bestLength > 384) positions = MIN(192, (U32)(bestLength - 384)); /* speed optimization */
+ assert(matchEndIdx > current + 8);
+ return MAX(positions, matchEndIdx - (current + 8));
+ }
}
FORCE_INLINE_TEMPLATE
void ZSTD_updateTree_internal(
- ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+ ZSTD_matchState_t* ms,
const BYTE* const ip, const BYTE* const iend,
- const U32 mls, const U32 extDict)
+ const U32 mls, const ZSTD_dictMode_e dictMode)
{
const BYTE* const base = ms->window.base;
U32 const target = (U32)(ip - base);
U32 idx = ms->nextToUpdate;
- DEBUGLOG(7, "ZSTD_updateTree_internal, from %u to %u (extDict:%u)",
- idx, target, extDict);
+ DEBUGLOG(6, "ZSTD_updateTree_internal, from %u to %u (dictMode:%u)",
+ idx, target, dictMode);
- while(idx < target)
- idx += ZSTD_insertBt1(ms, cParams, base+idx, iend, mls, extDict);
+ while(idx < target) {
+ U32 const forward = ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict);
+ assert(idx < (U32)(idx + forward));
+ idx += forward;
+ }
+ assert((size_t)(ip - base) <= (size_t)(U32)(-1));
+ assert((size_t)(iend - base) <= (size_t)(U32)(-1));
ms->nextToUpdate = target;
}
-void ZSTD_updateTree(
- ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
- const BYTE* ip, const BYTE* iend)
-{
- ZSTD_updateTree_internal(ms, cParams, ip, iend, cParams->searchLength, 0 /*extDict*/);
+void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) {
+ ZSTD_updateTree_internal(ms, ip, iend, ms->cParams.minMatch, ZSTD_noDict);
}
FORCE_INLINE_TEMPLATE
U32 ZSTD_insertBtAndGetAllMatches (
- ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
- const BYTE* const ip, const BYTE* const iLimit, int const extDict,
- U32 rep[ZSTD_REP_NUM], U32 const ll0,
- ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */)
+ ZSTD_match_t* matches, /* store result (found matches) in this table (presumed large enough) */
+ ZSTD_matchState_t* ms,
+ U32* nextToUpdate3,
+ const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode,
+ const U32 rep[ZSTD_REP_NUM],
+ U32 const ll0, /* tells if associated literal length is 0 or not. This value must be 0 or 1 */
+ const U32 lengthToBeat,
+ U32 const mls /* template */)
{
+ const ZSTD_compressionParameters* const cParams = &ms->cParams;
U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
+ U32 const maxDistance = 1U << cParams->windowLog;
const BYTE* const base = ms->window.base;
U32 const current = (U32)(ip-base);
U32 const hashLog = cParams->hashLog;
@@ -424,8 +568,10 @@
U32 const dictLimit = ms->window.dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
- U32 const btLow = btMask >= current ? 0 : current - btMask;
- U32 const windowLow = ms->window.lowLimit;
+ U32 const btLow = (btMask >= current) ? 0 : current - btMask;
+ U32 const windowValid = ms->window.lowLimit;
+ U32 const windowLow = ((current - windowValid) > maxDistance) ? current - maxDistance : windowValid;
+ U32 const matchLow = windowLow ? windowLow : 1;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 matchEndIdx = current+8+1; /* farthest referenced position of any match => detects repetitive patterns */
@@ -433,10 +579,24 @@
U32 mnum = 0;
U32 nbCompares = 1U << cParams->searchLog;
+ const ZSTD_matchState_t* dms = dictMode == ZSTD_dictMatchState ? ms->dictMatchState : NULL;
+ const ZSTD_compressionParameters* const dmsCParams =
+ dictMode == ZSTD_dictMatchState ? &dms->cParams : NULL;
+ const BYTE* const dmsBase = dictMode == ZSTD_dictMatchState ? dms->window.base : NULL;
+ const BYTE* const dmsEnd = dictMode == ZSTD_dictMatchState ? dms->window.nextSrc : NULL;
+ U32 const dmsHighLimit = dictMode == ZSTD_dictMatchState ? (U32)(dmsEnd - dmsBase) : 0;
+ U32 const dmsLowLimit = dictMode == ZSTD_dictMatchState ? dms->window.lowLimit : 0;
+ U32 const dmsIndexDelta = dictMode == ZSTD_dictMatchState ? windowLow - dmsHighLimit : 0;
+ U32 const dmsHashLog = dictMode == ZSTD_dictMatchState ? dmsCParams->hashLog : hashLog;
+ U32 const dmsBtLog = dictMode == ZSTD_dictMatchState ? dmsCParams->chainLog - 1 : btLog;
+ U32 const dmsBtMask = dictMode == ZSTD_dictMatchState ? (1U << dmsBtLog) - 1 : 0;
+ U32 const dmsBtLow = dictMode == ZSTD_dictMatchState && dmsBtMask < dmsHighLimit - dmsLowLimit ? dmsHighLimit - dmsBtMask : dmsLowLimit;
+
size_t bestLength = lengthToBeat-1;
- DEBUGLOG(7, "ZSTD_insertBtAndGetAllMatches");
+ DEBUGLOG(8, "ZSTD_insertBtAndGetAllMatches: current=%u", current);
/* check repCode */
+ assert(ll0 <= 1); /* necessarily 1 or 0 */
{ U32 const lastR = ZSTD_REP_NUM + ll0;
U32 repCode;
for (repCode = ll0; repCode < lastR; repCode++) {
@@ -449,18 +609,26 @@
repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch;
}
} else { /* repIndex < dictLimit || repIndex >= current */
- const BYTE* const repMatch = dictBase + repIndex;
+ const BYTE* const repMatch = dictMode == ZSTD_dictMatchState ?
+ dmsBase + repIndex - dmsIndexDelta :
+ dictBase + repIndex;
assert(current >= windowLow);
- if ( extDict /* this case only valid in extDict mode */
+ if ( dictMode == ZSTD_extDict
&& ( ((repOffset-1) /*intentional overflow*/ < current - windowLow) /* equivalent to `current > repIndex >= windowLow` */
& (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */)
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch;
+ }
+ if (dictMode == ZSTD_dictMatchState
+ && ( ((repOffset-1) /*intentional overflow*/ < current - (dmsLowLimit + dmsIndexDelta)) /* equivalent to `current > repIndex >= dmsLowLimit` */
+ & ((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */
+ && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
+ repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dmsEnd, prefixStart) + minMatch;
} }
/* save longer solution */
if (repLen > bestLength) {
- DEBUGLOG(8, "found rep-match %u of length %u",
- repCode - ll0, (U32)repLen);
+ DEBUGLOG(8, "found repCode %u (ll0:%u, offset:%u) of length %u",
+ repCode, ll0, repOffset, repLen);
bestLength = repLen;
matches[mnum].off = repCode - ll0;
matches[mnum].len = (U32)repLen;
@@ -472,11 +640,11 @@
/* HC3 match finder */
if ((mls == 3) /*static*/ && (bestLength < mls)) {
- U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip);
- if ((matchIndex3 > windowLow)
+ U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, nextToUpdate3, ip);
+ if ((matchIndex3 >= matchLow)
& (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) {
size_t mlen;
- if ((!extDict) /*static*/ || (matchIndex3 >= dictLimit)) {
+ if ((dictMode == ZSTD_noDict) /*static*/ || (dictMode == ZSTD_dictMatchState) /*static*/ || (matchIndex3 >= dictLimit)) {
const BYTE* const match = base + matchIndex3;
mlen = ZSTD_count(ip, match, iLimit);
} else {
@@ -498,17 +666,19 @@
(ip+mlen == iLimit) ) { /* best possible length */
ms->nextToUpdate = current+1; /* skip insertion */
return 1;
- } } } }
+ } } }
+ /* no dictMatchState lookup: dicts don't have a populated HC3 table */
+ }
hashTable[h] = current; /* Update Hash Table */
- while (nbCompares-- && (matchIndex > windowLow)) {
+ while (nbCompares-- && (matchIndex >= matchLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
assert(current > matchIndex);
- if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
+ if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) {
assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */
match = base + matchIndex;
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit);
@@ -520,8 +690,8 @@
}
if (matchLength > bestLength) {
- DEBUGLOG(8, "found match of length %u at distance %u",
- (U32)matchLength, current - matchIndex);
+ DEBUGLOG(8, "found match of length %u at distance %u (offCode=%u)",
+ (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
assert(matchEndIdx > matchIndex);
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
@@ -529,9 +699,10 @@
matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
matches[mnum].len = (U32)matchLength;
mnum++;
- if (matchLength > ZSTD_OPT_NUM) break;
- if (ip+matchLength == iLimit) { /* equal : no way to know if inf or sup */
- break; /* drop, to preserve bt consistency (miss a little bit of compression) */
+ if ( (matchLength > ZSTD_OPT_NUM)
+ | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
+ if (dictMode == ZSTD_dictMatchState) nbCompares = 0; /* break should also skip searching dms */
+ break; /* drop, to preserve bt consistency (miss a little bit of compression) */
}
}
@@ -552,6 +723,47 @@
*smallerPtr = *largerPtr = 0;
+ if (dictMode == ZSTD_dictMatchState && nbCompares) {
+ size_t const dmsH = ZSTD_hashPtr(ip, dmsHashLog, mls);
+ U32 dictMatchIndex = dms->hashTable[dmsH];
+ const U32* const dmsBt = dms->chainTable;
+ commonLengthSmaller = commonLengthLarger = 0;
+ while (nbCompares-- && (dictMatchIndex > dmsLowLimit)) {
+ const U32* const nextPtr = dmsBt + 2*(dictMatchIndex & dmsBtMask);
+ size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
+ const BYTE* match = dmsBase + dictMatchIndex;
+ matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dmsEnd, prefixStart);
+ if (dictMatchIndex+matchLength >= dmsHighLimit)
+ match = base + dictMatchIndex + dmsIndexDelta; /* to prepare for next usage of match[matchLength] */
+
+ if (matchLength > bestLength) {
+ matchIndex = dictMatchIndex + dmsIndexDelta;
+ DEBUGLOG(8, "found dms match of length %u at distance %u (offCode=%u)",
+ (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
+ if (matchLength > matchEndIdx - matchIndex)
+ matchEndIdx = matchIndex + (U32)matchLength;
+ bestLength = matchLength;
+ matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
+ matches[mnum].len = (U32)matchLength;
+ mnum++;
+ if ( (matchLength > ZSTD_OPT_NUM)
+ | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
+ break; /* drop, to guarantee consistency (miss a little bit of compression) */
+ }
+ }
+
+ if (dictMatchIndex <= dmsBtLow) { break; } /* beyond tree size, stop the search */
+ if (match[matchLength] < ip[matchLength]) {
+ commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
+ dictMatchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
+ } else {
+ /* match is larger than current */
+ commonLengthLarger = matchLength;
+ dictMatchIndex = nextPtr[0];
+ }
+ }
+ }
+
assert(matchEndIdx > current+8);
ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */
return mnum;
@@ -559,23 +771,27 @@
FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
- ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
- const BYTE* ip, const BYTE* const iHighLimit, int const extDict,
- U32 rep[ZSTD_REP_NUM], U32 const ll0,
- ZSTD_match_t* matches, U32 const lengthToBeat)
+ ZSTD_match_t* matches, /* store result (match found, increasing size) in this table */
+ ZSTD_matchState_t* ms,
+ U32* nextToUpdate3,
+ const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode,
+ const U32 rep[ZSTD_REP_NUM],
+ U32 const ll0,
+ U32 const lengthToBeat)
{
- U32 const matchLengthSearch = cParams->searchLength;
- DEBUGLOG(7, "ZSTD_BtGetAllMatches");
+ const ZSTD_compressionParameters* const cParams = &ms->cParams;
+ U32 const matchLengthSearch = cParams->minMatch;
+ DEBUGLOG(8, "ZSTD_BtGetAllMatches");
if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
- ZSTD_updateTree_internal(ms, cParams, ip, iHighLimit, matchLengthSearch, extDict);
+ ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode);
switch(matchLengthSearch)
{
- case 3 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 3);
+ case 3 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 3);
default :
- case 4 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 4);
- case 5 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 5);
+ case 4 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 4);
+ case 5 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 5);
case 7 :
- case 6 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 6);
+ case 6 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 6);
}
}
@@ -587,7 +803,7 @@
U32 rep[3];
} repcodes_t;
-repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
+static repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
{
repcodes_t newReps;
if (offset >= ZSTD_REP_NUM) { /* full offset */
@@ -609,65 +825,35 @@
}
-typedef struct {
- const BYTE* anchor;
- U32 litlen;
- U32 rawLitCost;
-} cachedLiteralPrice_t;
-
-static U32 ZSTD_rawLiteralsCost_cached(
- cachedLiteralPrice_t* const cachedLitPrice,
- const BYTE* const anchor, U32 const litlen,
- const optState_t* const optStatePtr)
+static U32 ZSTD_totalLen(ZSTD_optimal_t sol)
{
- U32 startCost;
- U32 remainingLength;
- const BYTE* startPosition;
+ return sol.litlen + sol.mlen;
+}
- if (anchor == cachedLitPrice->anchor) {
- startCost = cachedLitPrice->rawLitCost;
- startPosition = anchor + cachedLitPrice->litlen;
- assert(litlen >= cachedLitPrice->litlen);
- remainingLength = litlen - cachedLitPrice->litlen;
- } else {
- startCost = 0;
- startPosition = anchor;
- remainingLength = litlen;
+#if 0 /* debug */
+
+static void
+listStats(const U32* table, int lastEltID)
+{
+ int const nbElts = lastEltID + 1;
+ int enb;
+ for (enb=0; enb < nbElts; enb++) {
+ (void)table;
+ //RAWLOG(2, "%3i:%3i, ", enb, table[enb]);
+ RAWLOG(2, "%4i,", table[enb]);
}
-
- { U32 const rawLitCost = startCost + ZSTD_rawLiteralsCost(startPosition, remainingLength, optStatePtr);
- cachedLitPrice->anchor = anchor;
- cachedLitPrice->litlen = litlen;
- cachedLitPrice->rawLitCost = rawLitCost;
- return rawLitCost;
- }
+ RAWLOG(2, " \n");
}
-static U32 ZSTD_fullLiteralsCost_cached(
- cachedLiteralPrice_t* const cachedLitPrice,
- const BYTE* const anchor, U32 const litlen,
- const optState_t* const optStatePtr)
-{
- return ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
- + ZSTD_litLengthPrice(litlen, optStatePtr);
-}
+#endif
-static int ZSTD_literalsContribution_cached(
- cachedLiteralPrice_t* const cachedLitPrice,
- const BYTE* const anchor, U32 const litlen,
- const optState_t* const optStatePtr)
-{
- int const contribution = ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
- + ZSTD_litLengthContribution(litlen, optStatePtr);
- return contribution;
-}
-
-FORCE_INLINE_TEMPLATE
-size_t ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,seqStore_t* seqStore,
- U32 rep[ZSTD_REP_NUM],
- ZSTD_compressionParameters const* cParams,
- const void* src, size_t srcSize,
- const int optLevel, const int extDict)
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
+ seqStore_t* seqStore,
+ U32 rep[ZSTD_REP_NUM],
+ const void* src, size_t srcSize,
+ const int optLevel,
+ const ZSTD_dictMode_e dictMode)
{
optState_t* const optStatePtr = &ms->opt;
const BYTE* const istart = (const BYTE*)src;
@@ -677,72 +863,77 @@
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ms->window.base;
const BYTE* const prefixStart = base + ms->window.dictLimit;
+ const ZSTD_compressionParameters* const cParams = &ms->cParams;
U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
- U32 const minMatch = (cParams->searchLength == 3) ? 3 : 4;
+ U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4;
+ U32 nextToUpdate3 = ms->nextToUpdate;
ZSTD_optimal_t* const opt = optStatePtr->priceTable;
ZSTD_match_t* const matches = optStatePtr->matchTable;
- cachedLiteralPrice_t cachedLitPrice;
+ ZSTD_optimal_t lastSequence;
/* init */
- DEBUGLOG(5, "ZSTD_compressBlock_opt_generic");
- ms->nextToUpdate3 = ms->nextToUpdate;
- ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
+ DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u",
+ (U32)(ip - base), ms->window.dictLimit, ms->nextToUpdate);
+ assert(optLevel <= 2);
+ ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel);
ip += (ip==prefixStart);
- memset(&cachedLitPrice, 0, sizeof(cachedLitPrice));
/* Match Loop */
while (ip < ilimit) {
U32 cur, last_pos = 0;
- U32 best_mlen, best_off;
/* find first match */
{ U32 const litlen = (U32)(ip - anchor);
U32 const ll0 = !litlen;
- U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, ip, iend, extDict, rep, ll0, matches, minMatch);
+ U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch);
if (!nbMatches) { ip++; continue; }
/* initialize opt[0] */
{ U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; }
- opt[0].mlen = 1;
+ opt[0].mlen = 0; /* means is_a_literal */
opt[0].litlen = litlen;
+ opt[0].price = ZSTD_literalsContribution(anchor, litlen, optStatePtr, optLevel);
/* large match -> immediate encoding */
{ U32 const maxML = matches[nbMatches-1].len;
- DEBUGLOG(7, "found %u matches of maxLength=%u and offset=%u at cPos=%u => start new serie",
- nbMatches, maxML, matches[nbMatches-1].off, (U32)(ip-prefixStart));
+ U32 const maxOffset = matches[nbMatches-1].off;
+ DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new series",
+ nbMatches, maxML, maxOffset, (U32)(ip-prefixStart));
if (maxML > sufficient_len) {
- best_mlen = maxML;
- best_off = matches[nbMatches-1].off;
- DEBUGLOG(7, "large match (%u>%u), immediate encoding",
- best_mlen, sufficient_len);
+ lastSequence.litlen = litlen;
+ lastSequence.mlen = maxML;
+ lastSequence.off = maxOffset;
+ DEBUGLOG(6, "large match (%u>%u), immediate encoding",
+ maxML, sufficient_len);
cur = 0;
- last_pos = 1;
+ last_pos = ZSTD_totalLen(lastSequence);
goto _shortestPath;
} }
/* set prices for first matches starting position == 0 */
- { U32 const literalsPrice = ZSTD_fullLiteralsCost_cached(&cachedLitPrice, anchor, litlen, optStatePtr);
+ { U32 const literalsPrice = opt[0].price + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
U32 pos;
U32 matchNb;
- for (pos = 0; pos < minMatch; pos++) {
- opt[pos].mlen = 1;
- opt[pos].price = ZSTD_MAX_PRICE;
+ for (pos = 1; pos < minMatch; pos++) {
+ opt[pos].price = ZSTD_MAX_PRICE; /* mlen, litlen and price will be fixed during forward scanning */
}
for (matchNb = 0; matchNb < nbMatches; matchNb++) {
U32 const offset = matches[matchNb].off;
U32 const end = matches[matchNb].len;
repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0);
for ( ; pos <= end ; pos++ ) {
- U32 const matchPrice = literalsPrice + ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
- DEBUGLOG(7, "rPos:%u => set initial price : %u",
- pos, matchPrice);
+ U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
+ U32 const sequencePrice = literalsPrice + matchPrice;
+ DEBUGLOG(7, "rPos:%u => set initial price : %.2f",
+ pos, ZSTD_fCost(sequencePrice));
opt[pos].mlen = pos;
opt[pos].off = offset;
opt[pos].litlen = litlen;
- opt[pos].price = matchPrice;
+ opt[pos].price = sequencePrice;
+ ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
} }
last_pos = pos-1;
@@ -753,55 +944,67 @@
for (cur = 1; cur <= last_pos; cur++) {
const BYTE* const inr = ip + cur;
assert(cur < ZSTD_OPT_NUM);
+ DEBUGLOG(7, "cPos:%zi==rPos:%u", inr-istart, cur)
/* Fix current position with one literal if cheaper */
- { U32 const litlen = (opt[cur-1].mlen == 1) ? opt[cur-1].litlen + 1 : 1;
- int price; /* note : contribution can be negative */
- if (cur > litlen) {
- price = opt[cur - litlen].price + ZSTD_literalsContribution(inr-litlen, litlen, optStatePtr);
- } else {
- price = ZSTD_literalsContribution_cached(&cachedLitPrice, anchor, litlen, optStatePtr);
- }
+ { U32 const litlen = (opt[cur-1].mlen == 0) ? opt[cur-1].litlen + 1 : 1;
+ int const price = opt[cur-1].price
+ + ZSTD_rawLiteralsCost(ip+cur-1, 1, optStatePtr, optLevel)
+ + ZSTD_litLengthPrice(litlen, optStatePtr, optLevel)
+ - ZSTD_litLengthPrice(litlen-1, optStatePtr, optLevel);
assert(price < 1000000000); /* overflow check */
if (price <= opt[cur].price) {
- DEBUGLOG(7, "rPos:%u : better price (%u<%u) using literal",
- cur, price, opt[cur].price);
- opt[cur].mlen = 1;
+ DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)",
+ inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen,
+ opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
+ opt[cur].mlen = 0;
opt[cur].off = 0;
opt[cur].litlen = litlen;
opt[cur].price = price;
memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep));
- } }
+ } else {
+ DEBUGLOG(7, "cPos:%zi==rPos:%u : literal would cost more (%.2f>%.2f) (hist:%u,%u,%u)",
+ inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price),
+ opt[cur].rep[0], opt[cur].rep[1], opt[cur].rep[2]);
+ }
+ }
/* last match must start at a minimum distance of 8 from oend */
if (inr > ilimit) continue;
if (cur == last_pos) break;
- if ( (optLevel==0) /*static*/
- && (opt[cur+1].price <= opt[cur].price) )
+ if ( (optLevel==0) /*static_test*/
+ && (opt[cur+1].price <= opt[cur].price + (BITCOST_MULTIPLIER/2)) ) {
+ DEBUGLOG(7, "move to next rPos:%u : price is <=", cur+1);
continue; /* skip unpromising positions; about ~+6% speed, -0.01 ratio */
+ }
- { U32 const ll0 = (opt[cur].mlen != 1);
- U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0;
- U32 const previousPrice = (cur > litlen) ? opt[cur-litlen].price : 0;
- U32 const basePrice = previousPrice + ZSTD_fullLiteralsCost(inr-litlen, litlen, optStatePtr);
- U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, inr, iend, extDict, opt[cur].rep, ll0, matches, minMatch);
+ { U32 const ll0 = (opt[cur].mlen != 0);
+ U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0;
+ U32 const previousPrice = opt[cur].price;
+ U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
+ U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, inr, iend, dictMode, opt[cur].rep, ll0, minMatch);
U32 matchNb;
- if (!nbMatches) continue;
+ if (!nbMatches) {
+ DEBUGLOG(7, "rPos:%u : no match found", cur);
+ continue;
+ }
{ U32 const maxML = matches[nbMatches-1].len;
- DEBUGLOG(7, "rPos:%u, found %u matches, of maxLength=%u",
- cur, nbMatches, maxML);
+ DEBUGLOG(7, "cPos:%zi==rPos:%u, found %u matches, of maxLength=%u",
+ inr-istart, cur, nbMatches, maxML);
if ( (maxML > sufficient_len)
- | (cur + maxML >= ZSTD_OPT_NUM) ) {
- best_mlen = maxML;
- best_off = matches[nbMatches-1].off;
- last_pos = cur + 1;
+ || (cur + maxML >= ZSTD_OPT_NUM) ) {
+ lastSequence.mlen = maxML;
+ lastSequence.off = matches[nbMatches-1].off;
+ lastSequence.litlen = litlen;
+ cur -= (opt[cur].mlen==0) ? opt[cur].litlen : 0; /* last sequence is actually only literals, fix cur to last match - note : may underflow, in which case, it's first sequence, and it's okay */
+ last_pos = cur + ZSTD_totalLen(lastSequence);
+ if (cur > ZSTD_OPT_NUM) cur = 0; /* underflow => first match */
goto _shortestPath;
- }
- }
+ } }
/* set prices using matches found at position == cur */
for (matchNb = 0; matchNb < nbMatches; matchNb++) {
@@ -811,113 +1014,233 @@
U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch;
U32 mlen;
- DEBUGLOG(7, "testing match %u => offCode=%u, mlen=%u, llen=%u",
+ DEBUGLOG(7, "testing match %u => offCode=%4u, mlen=%2u, llen=%2u",
matchNb, matches[matchNb].off, lastML, litlen);
- for (mlen = lastML; mlen >= startML; mlen--) {
+ for (mlen = lastML; mlen >= startML; mlen--) { /* scan downward */
U32 const pos = cur + mlen;
int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel);
if ((pos > last_pos) || (price < opt[pos].price)) {
- DEBUGLOG(7, "rPos:%u => new better price (%u<%u)",
- pos, price, opt[pos].price);
- while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; }
+ DEBUGLOG(7, "rPos:%u (ml=%2u) => new better price (%.2f<%.2f)",
+ pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
+ while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } /* fill empty positions */
opt[pos].mlen = mlen;
opt[pos].off = offset;
opt[pos].litlen = litlen;
opt[pos].price = price;
+ ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
} else {
- if (optLevel==0) break; /* gets ~+10% speed for about -0.01 ratio loss */
+ DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)",
+ pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
+ if (optLevel==0) break; /* early update abort; gets ~+10% speed for about -0.01 ratio loss */
}
} } }
} /* for (cur = 1; cur <= last_pos; cur++) */
- best_mlen = opt[last_pos].mlen;
- best_off = opt[last_pos].off;
- cur = last_pos - best_mlen;
+ lastSequence = opt[last_pos];
+ cur = last_pos > ZSTD_totalLen(lastSequence) ? last_pos - ZSTD_totalLen(lastSequence) : 0; /* single sequence, and it starts before `ip` */
+ assert(cur < ZSTD_OPT_NUM); /* control overflow*/
_shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
- assert(opt[0].mlen == 1);
+ assert(opt[0].mlen == 0);
- /* reverse traversal */
- DEBUGLOG(7, "start reverse traversal (last_pos:%u, cur:%u)",
- last_pos, cur);
- { U32 selectedMatchLength = best_mlen;
- U32 selectedOffset = best_off;
- U32 pos = cur;
- while (1) {
- U32 const mlen = opt[pos].mlen;
- U32 const off = opt[pos].off;
- opt[pos].mlen = selectedMatchLength;
- opt[pos].off = selectedOffset;
- selectedMatchLength = mlen;
- selectedOffset = off;
- if (mlen > pos) break;
- pos -= mlen;
- } }
+ { U32 const storeEnd = cur + 1;
+ U32 storeStart = storeEnd;
+ U32 seqPos = cur;
- /* save sequences */
- { U32 pos;
- for (pos=0; pos < last_pos; ) {
- U32 const llen = (U32)(ip - anchor);
- U32 const mlen = opt[pos].mlen;
- U32 const offset = opt[pos].off;
- if (mlen == 1) { ip++; pos++; continue; } /* literal position => move on */
- pos += mlen; ip += mlen;
+ DEBUGLOG(6, "start reverse traversal (last_pos:%u, cur:%u)",
+ last_pos, cur); (void)last_pos;
+ assert(storeEnd < ZSTD_OPT_NUM);
+ DEBUGLOG(6, "last sequence copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
+ storeEnd, lastSequence.litlen, lastSequence.mlen, lastSequence.off);
+ opt[storeEnd] = lastSequence;
+ while (seqPos > 0) {
+ U32 const backDist = ZSTD_totalLen(opt[seqPos]);
+ storeStart--;
+ DEBUGLOG(6, "sequence from rPos=%u copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
+ seqPos, storeStart, opt[seqPos].litlen, opt[seqPos].mlen, opt[seqPos].off);
+ opt[storeStart] = opt[seqPos];
+ seqPos = (seqPos > backDist) ? seqPos - backDist : 0;
+ }
- /* repcodes update : like ZSTD_updateRep(), but update in place */
- if (offset >= ZSTD_REP_NUM) { /* full offset */
- rep[2] = rep[1];
- rep[1] = rep[0];
- rep[0] = offset - ZSTD_REP_MOVE;
- } else { /* repcode */
- U32 const repCode = offset + (llen==0);
- if (repCode) { /* note : if repCode==0, no change */
- U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
- if (repCode >= 2) rep[2] = rep[1];
- rep[1] = rep[0];
- rep[0] = currentOffset;
+ /* save sequences */
+ DEBUGLOG(6, "sending selected sequences into seqStore")
+ { U32 storePos;
+ for (storePos=storeStart; storePos <= storeEnd; storePos++) {
+ U32 const llen = opt[storePos].litlen;
+ U32 const mlen = opt[storePos].mlen;
+ U32 const offCode = opt[storePos].off;
+ U32 const advance = llen + mlen;
+ DEBUGLOG(6, "considering seq starting at %zi, llen=%u, mlen=%u",
+ anchor - istart, (unsigned)llen, (unsigned)mlen);
+
+ if (mlen==0) { /* only literals => must be last "sequence", actually starting a new stream of sequences */
+ assert(storePos == storeEnd); /* must be last sequence */
+ ip = anchor + llen; /* last "sequence" is a bunch of literals => don't progress anchor */
+ continue; /* will finish */
}
- }
- ZSTD_updateStats(optStatePtr, llen, anchor, offset, mlen);
- ZSTD_storeSeq(seqStore, llen, anchor, offset, mlen-MINMATCH);
- anchor = ip;
- } }
- ZSTD_setLog2Prices(optStatePtr);
+ /* repcodes update : like ZSTD_updateRep(), but update in place */
+ if (offCode >= ZSTD_REP_NUM) { /* full offset */
+ rep[2] = rep[1];
+ rep[1] = rep[0];
+ rep[0] = offCode - ZSTD_REP_MOVE;
+ } else { /* repcode */
+ U32 const repCode = offCode + (llen==0);
+ if (repCode) { /* note : if repCode==0, no change */
+ U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
+ if (repCode >= 2) rep[2] = rep[1];
+ rep[1] = rep[0];
+ rep[0] = currentOffset;
+ } }
+
+ assert(anchor + llen <= iend);
+ ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen);
+ ZSTD_storeSeq(seqStore, llen, anchor, offCode, mlen-MINMATCH);
+ anchor += advance;
+ ip = anchor;
+ } }
+ ZSTD_setBasePrices(optStatePtr, optLevel);
+ }
+
} /* while (ip < ilimit) */
/* Return the last literals size */
- return iend - anchor;
+ return (size_t)(iend - anchor);
}
size_t ZSTD_compressBlock_btopt(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
- ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+ const void* src, size_t srcSize)
{
DEBUGLOG(5, "ZSTD_compressBlock_btopt");
- return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 0 /*extDict*/);
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict);
+}
+
+
+/* used in 2-pass strategy */
+static U32 ZSTD_upscaleStat(unsigned* table, U32 lastEltIndex, int bonus)
+{
+ U32 s, sum=0;
+ assert(ZSTD_FREQ_DIV+bonus >= 0);
+ for (s=0; s<lastEltIndex+1; s++) {
+ table[s] <<= ZSTD_FREQ_DIV+bonus;
+ table[s]--;
+ sum += table[s];
+ }
+ return sum;
+}
+
+/* used in 2-pass strategy */
+MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr)
+{
+ if (ZSTD_compressedLiterals(optPtr))
+ optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0);
+ optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 0);
+ optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 0);
+ optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 0);
+}
+
+/* ZSTD_initStats_ultra():
+ * make a first compression pass, just to seed stats with more accurate starting values.
+ * only works on first block, with no dictionary and no ldm.
+ * this function cannot error, hence its contract must be respected.
+ */
+static void
+ZSTD_initStats_ultra(ZSTD_matchState_t* ms,
+ seqStore_t* seqStore,
+ U32 rep[ZSTD_REP_NUM],
+ const void* src, size_t srcSize)
+{
+ U32 tmpRep[ZSTD_REP_NUM]; /* updated rep codes will sink here */
+ memcpy(tmpRep, rep, sizeof(tmpRep));
+
+ DEBUGLOG(4, "ZSTD_initStats_ultra (srcSize=%zu)", srcSize);
+ assert(ms->opt.litLengthSum == 0); /* first block */
+ assert(seqStore->sequences == seqStore->sequencesStart); /* no ldm */
+ assert(ms->window.dictLimit == ms->window.lowLimit); /* no dictionary */
+ assert(ms->window.dictLimit - ms->nextToUpdate <= 1); /* no prefix (note: intentional overflow, defined as 2-complement) */
+
+ ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict); /* generate stats into ms->opt*/
+
+ /* invalidate first scan from history */
+ ZSTD_resetSeqStore(seqStore);
+ ms->window.base -= srcSize;
+ ms->window.dictLimit += (U32)srcSize;
+ ms->window.lowLimit = ms->window.dictLimit;
+ ms->nextToUpdate = ms->window.dictLimit;
+
+ /* re-inforce weight of collected statistics */
+ ZSTD_upscaleStats(&ms->opt);
}
size_t ZSTD_compressBlock_btultra(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
- ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+ const void* src, size_t srcSize)
{
- return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 0 /*extDict*/);
+ DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize);
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
+}
+
+size_t ZSTD_compressBlock_btultra2(
+ ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+ const void* src, size_t srcSize)
+{
+ U32 const current = (U32)((const BYTE*)src - ms->window.base);
+ DEBUGLOG(5, "ZSTD_compressBlock_btultra2 (srcSize=%zu)", srcSize);
+
+ /* 2-pass strategy:
+ * this strategy makes a first pass over first block to collect statistics
+ * and seed next round's statistics with it.
+ * After 1st pass, function forgets everything, and starts a new block.
+ * Consequently, this can only work if no data has been previously loaded in tables,
+ * aka, no dictionary, no prefix, no ldm preprocessing.
+ * The compression ratio gain is generally small (~0.5% on first block),
+ * the cost is 2x cpu time on first block. */
+ assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
+ if ( (ms->opt.litLengthSum==0) /* first block */
+ && (seqStore->sequences == seqStore->sequencesStart) /* no ldm */
+ && (ms->window.dictLimit == ms->window.lowLimit) /* no dictionary */
+ && (current == ms->window.dictLimit) /* start of frame, nothing already loaded nor skipped */
+ && (srcSize > ZSTD_PREDEF_THRESHOLD)
+ ) {
+ ZSTD_initStats_ultra(ms, seqStore, rep, src, srcSize);
+ }
+
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
+}
+
+size_t ZSTD_compressBlock_btopt_dictMatchState(
+ ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+ const void* src, size_t srcSize)
+{
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState);
+}
+
+size_t ZSTD_compressBlock_btultra_dictMatchState(
+ ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+ const void* src, size_t srcSize)
+{
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState);
}
size_t ZSTD_compressBlock_btopt_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
- ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+ const void* src, size_t srcSize)
{
- return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 1 /*extDict*/);
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict);
}
size_t ZSTD_compressBlock_btultra_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
- ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+ const void* src, size_t srcSize)
{
- return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 1 /*extDict*/);
+ return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict);
}
+
+/* note : no btultra2 variant for extDict nor dictMatchState,
+ * because btultra2 is not meant to work with dictionaries
+ * and is only specific for the first block (no prefix) */