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Merge branch 'dev' into fracFse

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This commit is contained in:
Yann Collet 2018-05-24 14:09:49 -07:00
commit b5ef32fea7
10 changed files with 567 additions and 160 deletions
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3
doc/zstd_compression_format.md
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@ -603,6 +603,7 @@ Let's call its first byte `byte0`.
- `if (byte0 == 0)` : there are no sequences.
The sequence section stops there.
Decompressed content is defined entirely as Literals Section content.
The FSE tables used in `Repeat_Mode` aren't updated.
- `if (byte0 < 128)` : `Number_of_Sequences = byte0` . Uses 1 byte.
- `if (byte0 < 255)` : `Number_of_Sequences = ((byte0-128) << 8) + byte1` . Uses 2 bytes.
- `if (byte0 == 255)`: `Number_of_Sequences = byte1 + (byte2<<8) + 0x7F00` . Uses 3 bytes.
@ -631,7 +632,7 @@ They follow the same enumeration :
No distribution table will be present.
- `RLE_Mode` : The table description consists of a single byte.
This code will be repeated for all sequences.
- `Repeat_Mode` : The table used in the previous `Compressed_Block` will be used again,
- `Repeat_Mode` : The table used in the previous `Compressed_Block` with `Number_of_Sequences > 0` will be used again,
or if this is the first block, table in the dictionary will be used
No distribution table will be present.
Note that this includes `RLE_mode`, so if `Repeat_Mode` follows `RLE_Mode`, the same symbol will be repeated.

15
lib/common/entropy_common.c
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@ -72,7 +72,19 @@ size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* t
unsigned charnum = 0;
int previous0 = 0;
if (hbSize < 4) return ERROR(srcSize_wrong);
if (hbSize < 4) {
/* This function only works when hbSize >= 4 */
char buffer[4];
memset(buffer, 0, sizeof(buffer));
memcpy(buffer, headerBuffer, hbSize);
{ size_t const countSize = FSE_readNCount(normalizedCounter, maxSVPtr, tableLogPtr,
buffer, sizeof(buffer));
if (FSE_isError(countSize)) return countSize;
if (countSize > hbSize) return ERROR(corruption_detected);
return countSize;
} }
assert(hbSize >= 4);
bitStream = MEM_readLE32(ip);
nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG; /* extract tableLog */
if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
@ -105,6 +117,7 @@ size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* t
if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
while (charnum < n0) normalizedCounter[charnum++] = 0;
if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
assert((bitCount >> 3) <= 3); /* For first condition to work */
ip += bitCount>>3;
bitCount &= 7;
bitStream = MEM_readLE32(ip) >> bitCount;

3
lib/common/fse.h
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@ -591,8 +591,9 @@ MEM_STATIC U32 FSE_getMaxNbBits(const void* symbolTTPtr, U32 symbolValue)
* Approximate symbol cost, as fractional value, using fixed-point format (accuracyLog fractional bits)
* note 1 : assume symbolValue is valid (<= maxSymbolValue)
* note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
MEM_STATIC U32 FSE_bitCost(const FSE_symbolCompressionTransform* symbolTT, U32 tableLog, U32 symbolValue, U32 accuracyLog)
MEM_STATIC U32 FSE_bitCost(const void* symbolTTPtr, U32 tableLog, U32 symbolValue, U32 accuracyLog)
{
const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
U32 const minNbBits = symbolTT[symbolValue].deltaNbBits >> 16;
U32 const threshold = (minNbBits+1) << 16;
assert(tableLog < 16);

446
lib/compress/zstd_compress.c
View File

@ -946,10 +946,10 @@ static void ZSTD_reset_compressedBlockState(ZSTD_compressedBlockState_t* bs)
int i;
for (i = 0; i < ZSTD_REP_NUM; ++i)
bs->rep[i] = repStartValue[i];
bs->entropy.hufCTable_repeatMode = HUF_repeat_none;
bs->entropy.offcode_repeatMode = FSE_repeat_none;
bs->entropy.matchlength_repeatMode = FSE_repeat_none;
bs->entropy.litlength_repeatMode = FSE_repeat_none;
bs->entropy.huf.repeatMode = HUF_repeat_none;
bs->entropy.fse.offcode_repeatMode = FSE_repeat_none;
bs->entropy.fse.matchlength_repeatMode = FSE_repeat_none;
bs->entropy.fse.litlength_repeatMode = FSE_repeat_none;
}
/*! ZSTD_invalidateMatchState()
@ -963,6 +963,7 @@ static void ZSTD_invalidateMatchState(ZSTD_matchState_t* ms)
ms->nextToUpdate = ms->window.dictLimit + 1;
ms->loadedDictEnd = 0;
ms->opt.litLengthSum = 0; /* force reset of btopt stats */
ms->dictMatchState = NULL;
}
/*! ZSTD_continueCCtx() :
@ -1203,42 +1204,80 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
U64 pledgedSrcSize,
ZSTD_buffered_policy_e zbuff)
{
/* We have a choice between copying the dictionary context into the working
* context, or referencing the dictionary context from the working context
* in-place. We decide here which strategy to use. */
const int attachDict = ( pledgedSrcSize <= 8 KB
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN )
&& !params.forceWindow /* dictMatchState isn't correctly
* handled in _enforceMaxDist */
&& cdict->cParams.strategy == ZSTD_fast
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
cdict->cParams);
{ unsigned const windowLog = params.cParams.windowLog;
assert(windowLog != 0);
/* Copy only compression parameters related to tables. */
params.cParams = cdict->cParams;
params.cParams.windowLog = windowLog;
ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize, ZSTDcrp_noMemset, zbuff);
ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
attachDict ? ZSTDcrp_continue : ZSTDcrp_noMemset,
zbuff);
assert(cctx->appliedParams.cParams.strategy == cdict->cParams.strategy);
assert(cctx->appliedParams.cParams.hashLog == cdict->cParams.hashLog);
assert(cctx->appliedParams.cParams.chainLog == cdict->cParams.chainLog);
}
/* copy tables */
{ size_t const chainSize = (cdict->cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict->cParams.chainLog);
size_t const hSize = (size_t)1 << cdict->cParams.hashLog;
size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace); /* presumes all tables follow each other */
}
/* Zero the hashTable3, since the cdict never fills it */
{ size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
assert(cdict->matchState.hashLog3 == 0);
memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
if (attachDict) {
const U32 cdictLen = (U32)( cdict->matchState.window.nextSrc
- cdict->matchState.window.base);
if (cdictLen == 0) {
/* don't even attach dictionaries with no contents */
DEBUGLOG(4, "skipping attaching empty dictionary");
} else {
DEBUGLOG(4, "attaching dictionary into context");
cctx->blockState.matchState.dictMatchState = &cdict->matchState;
/* prep working match state so dict matches never have negative indices
* when they are translated to the working context's index space. */
if (cctx->blockState.matchState.window.dictLimit < cdictLen) {
cctx->blockState.matchState.window.nextSrc =
cctx->blockState.matchState.window.base + cdictLen;
ZSTD_window_clear(&cctx->blockState.matchState.window);
}
cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
}
} else {
DEBUGLOG(4, "copying dictionary into context");
/* copy tables */
{ size_t const chainSize = (cdict->cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict->cParams.chainLog);
size_t const hSize = (size_t)1 << cdict->cParams.hashLog;
size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace); /* presumes all tables follow each other */
}
/* Zero the hashTable3, since the cdict never fills it */
{ size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
assert(cdict->matchState.hashLog3 == 0);
memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
}
/* copy dictionary offsets */
{
ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
dstMatchState->window = srcMatchState->window;
dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
}
}
/* copy dictionary offsets */
{
ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
dstMatchState->window = srcMatchState->window;
dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
}
cctx->dictID = cdict->dictID;
/* copy block state */
@ -1455,8 +1494,8 @@ static size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, cons
static size_t ZSTD_minGain(size_t srcSize) { return (srcSize >> 6) + 2; }
static size_t ZSTD_compressLiterals (ZSTD_entropyCTables_t const* prevEntropy,
ZSTD_entropyCTables_t* nextEntropy,
static size_t ZSTD_compressLiterals (ZSTD_hufCTables_t const* prevHuf,
ZSTD_hufCTables_t* nextHuf,
ZSTD_strategy strategy, int disableLiteralCompression,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
@ -1473,27 +1512,25 @@ static size_t ZSTD_compressLiterals (ZSTD_entropyCTables_t const* prevEntropy,
disableLiteralCompression);
/* Prepare nextEntropy assuming reusing the existing table */
nextEntropy->hufCTable_repeatMode = prevEntropy->hufCTable_repeatMode;
memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable,
sizeof(prevEntropy->hufCTable));
memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
if (disableLiteralCompression)
return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
/* small ? don't even attempt compression (speed opt) */
# define COMPRESS_LITERALS_SIZE_MIN 63
{ size_t const minLitSize = (prevEntropy->hufCTable_repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
{ size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
if (srcSize <= minLitSize) return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
}
if (dstCapacity < lhSize+1) return ERROR(dstSize_tooSmall); /* not enough space for compression */
{ HUF_repeat repeat = prevEntropy->hufCTable_repeatMode;
{ HUF_repeat repeat = prevHuf->repeatMode;
int const preferRepeat = strategy < ZSTD_lazy ? srcSize <= 1024 : 0;
if (repeat == HUF_repeat_valid && lhSize == 3) singleStream = 1;
cLitSize = singleStream ? HUF_compress1X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextEntropy->hufCTable, &repeat, preferRepeat, bmi2)
workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2)
: HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextEntropy->hufCTable, &repeat, preferRepeat, bmi2);
workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2);
if (repeat != HUF_repeat_none) {
/* reused the existing table */
hType = set_repeat;
@ -1501,17 +1538,17 @@ static size_t ZSTD_compressLiterals (ZSTD_entropyCTables_t const* prevEntropy,
}
if ((cLitSize==0) | (cLitSize >= srcSize - minGain) | ERR_isError(cLitSize)) {
memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable, sizeof(prevEntropy->hufCTable));
memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
}
if (cLitSize==1) {
memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable, sizeof(prevEntropy->hufCTable));
memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
return ZSTD_compressRleLiteralsBlock(dst, dstCapacity, src, srcSize);
}
if (hType == set_compressed) {
/* using a newly constructed table */
nextEntropy->hufCTable_repeatMode = HUF_repeat_check;
nextHuf->repeatMode = HUF_repeat_check;
}
/* Build header */
@ -1561,6 +1598,137 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
}
/**
* -log2(x / 256) lookup table for x in [0, 256).
* If x == 0: Return 0
* Else: Return floor(-log2(x / 256) * 256)
*/
static unsigned const kInverseProbabiltyLog256[256] = {
0, 2048, 1792, 1642, 1536, 1453, 1386, 1329, 1280, 1236, 1197, 1162,
1130, 1100, 1073, 1047, 1024, 1001, 980, 960, 941, 923, 906, 889,
874, 859, 844, 830, 817, 804, 791, 779, 768, 756, 745, 734,
724, 714, 704, 694, 685, 676, 667, 658, 650, 642, 633, 626,
618, 610, 603, 595, 588, 581, 574, 567, 561, 554, 548, 542,
535, 529, 523, 517, 512, 506, 500, 495, 489, 484, 478, 473,
468, 463, 458, 453, 448, 443, 438, 434, 429, 424, 420, 415,
411, 407, 402, 398, 394, 390, 386, 382, 377, 373, 370, 366,
362, 358, 354, 350, 347, 343, 339, 336, 332, 329, 325, 322,
318, 315, 311, 308, 305, 302, 298, 295, 292, 289, 286, 282,
279, 276, 273, 270, 267, 264, 261, 258, 256, 253, 250, 247,
244, 241, 239, 236, 233, 230, 228, 225, 222, 220, 217, 215,
212, 209, 207, 204, 202, 199, 197, 194, 192, 190, 187, 185,
182, 180, 178, 175, 173, 171, 168, 166, 164, 162, 159, 157,
155, 153, 151, 149, 146, 144, 142, 140, 138, 136, 134, 132,
130, 128, 126, 123, 121, 119, 117, 115, 114, 112, 110, 108,
106, 104, 102, 100, 98, 96, 94, 93, 91, 89, 87, 85,
83, 82, 80, 78, 76, 74, 73, 71, 69, 67, 66, 64,
62, 61, 59, 57, 55, 54, 52, 50, 49, 47, 46, 44,
42, 41, 39, 37, 36, 34, 33, 31, 30, 28, 26, 25,
23, 22, 20, 19, 17, 16, 14, 13, 11, 10, 8, 7,
5, 4, 2, 1,
};
/**
* Returns the cost in bits of encoding the distribution described by count
* using the entropy bound.
*/
static size_t ZSTD_entropyCost(unsigned const* count, unsigned const max, size_t const total)
{
unsigned cost = 0;
unsigned s;
for (s = 0; s <= max; ++s) {
unsigned norm = (unsigned)((256 * count[s]) / total);
if (count[s] != 0 && norm == 0)
norm = 1;
assert(count[s] < total);
cost += count[s] * kInverseProbabiltyLog256[norm];
}
return cost >> 8;
}
/**
* Returns the cost in bits of encoding the distribution in count using the
* table described by norm. The max symbol support by norm is assumed >= max.
* norm must be valid for every symbol with non-zero probability in count.
*/
static size_t ZSTD_crossEntropyCost(short const* norm, unsigned accuracyLog,
unsigned const* count, unsigned const max)
{
unsigned const shift = 8 - accuracyLog;
size_t cost = 0;
unsigned s;
assert(accuracyLog <= 8);
for (s = 0; s <= max; ++s) {
unsigned const normAcc = norm[s] != -1 ? norm[s] : 1;
unsigned const norm256 = normAcc << shift;
assert(norm256 > 0);
assert(norm256 < 256);
cost += count[s] * kInverseProbabiltyLog256[norm256];
}
return cost >> 8;
}
static unsigned ZSTD_getFSEMaxSymbolValue(FSE_CTable const* ctable) {
void const* ptr = ctable;
U16 const* u16ptr = (U16 const*)ptr;
U32 const maxSymbolValue = MEM_read16(u16ptr + 1);
return maxSymbolValue;
}
/**
* Returns the cost in bits of encoding the distribution in count using ctable.
* Returns an error if ctable cannot represent all the symbols in count.
*/
static size_t ZSTD_fseBitCost(
FSE_CTable const* ctable,
unsigned const* count,
unsigned const max)
{
unsigned const kAccuracyLog = 8;
size_t cost = 0;
unsigned s;
FSE_CState_t cstate;
FSE_initCState(&cstate, ctable);
if (ZSTD_getFSEMaxSymbolValue(ctable) < max) {
DEBUGLOG(5, "Repeat FSE_CTable has maxSymbolValue %u < %u",
ZSTD_getFSEMaxSymbolValue(ctable), max);
return ERROR(GENERIC);
}
for (s = 0; s <= max; ++s) {
unsigned const tableLog = cstate.stateLog;
unsigned const badCost = (tableLog + 1) << kAccuracyLog;
unsigned const bitCost = FSE_bitCost(cstate.symbolTT, tableLog, s, kAccuracyLog);
if (count[s] == 0)
continue;
if (bitCost >= badCost) {
DEBUGLOG(5, "Repeat FSE_CTable has Prob[%u] == 0", s);
return ERROR(GENERIC);
}
cost += count[s] * bitCost;
}
return cost >> kAccuracyLog;
}
/**
* Returns the cost in bytes of encoding the normalized count header.
* Returns an error if any of the helper functions return an error.
*/
static size_t ZSTD_NCountCost(unsigned const* count, unsigned const max,
size_t const nbSeq, unsigned const FSELog)
{
BYTE wksp[FSE_NCOUNTBOUND];
S16 norm[MaxSeq + 1];
const U32 tableLog = FSE_optimalTableLog(FSELog, nbSeq, max);
CHECK_F(FSE_normalizeCount(norm, tableLog, count, nbSeq, max));
return FSE_writeNCount(wksp, sizeof(wksp), norm, max, tableLog);
}
typedef enum {
ZSTD_defaultDisallowed = 0,
ZSTD_defaultAllowed = 1
@ -1568,37 +1736,73 @@ typedef enum {
MEM_STATIC
symbolEncodingType_e ZSTD_selectEncodingType(
FSE_repeat* repeatMode, size_t const mostFrequent, size_t nbSeq,
U32 defaultNormLog, ZSTD_defaultPolicy_e const isDefaultAllowed)
FSE_repeat* repeatMode, unsigned const* count, unsigned const max,
size_t const mostFrequent, size_t nbSeq, unsigned const FSELog,
FSE_CTable const* prevCTable,
short const* defaultNorm, U32 defaultNormLog,
ZSTD_defaultPolicy_e const isDefaultAllowed,
ZSTD_strategy const strategy)
{
#define MIN_SEQ_FOR_DYNAMIC_FSE 64
#define MAX_SEQ_FOR_STATIC_FSE 1000
ZSTD_STATIC_ASSERT(ZSTD_defaultDisallowed == 0 && ZSTD_defaultAllowed != 0);
if ((mostFrequent == nbSeq) && (!isDefaultAllowed || nbSeq > 2)) {
if (mostFrequent == nbSeq) {
*repeatMode = FSE_repeat_none;
if (isDefaultAllowed && nbSeq <= 2) {
/* Prefer set_basic over set_rle when there are 2 or less symbols,
* since RLE uses 1 byte, but set_basic uses 5-6 bits per symbol.
* If basic encoding isn't possible, always choose RLE.
*/
DEBUGLOG(5, "Selected set_basic");
return set_basic;
}
DEBUGLOG(5, "Selected set_rle");
/* Prefer set_basic over set_rle when there are 2 or less symbols,
* since RLE uses 1 byte, but set_basic uses 5-6 bits per symbol.
* If basic encoding isn't possible, always choose RLE.
*/
*repeatMode = FSE_repeat_check;
return set_rle;
}
if ( isDefaultAllowed
&& (*repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
DEBUGLOG(5, "Selected set_repeat");
return set_repeat;
}
if ( isDefaultAllowed
&& ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (defaultNormLog-1)))) ) {
DEBUGLOG(5, "Selected set_basic");
/* The format allows default tables to be repeated, but it isn't useful.
* When using simple heuristics to select encoding type, we don't want
* to confuse these tables with dictionaries. When running more careful
* analysis, we don't need to waste time checking both repeating tables
* and default tables.
*/
*repeatMode = FSE_repeat_none;
return set_basic;
if (strategy < ZSTD_lazy) {
if (isDefaultAllowed) {
if ((*repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
DEBUGLOG(5, "Selected set_repeat");
return set_repeat;
}
if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (defaultNormLog-1)))) {
DEBUGLOG(5, "Selected set_basic");
/* The format allows default tables to be repeated, but it isn't useful.
* When using simple heuristics to select encoding type, we don't want
* to confuse these tables with dictionaries. When running more careful
* analysis, we don't need to waste time checking both repeating tables
* and default tables.
*/
*repeatMode = FSE_repeat_none;
return set_basic;
}
}
} else {
size_t const basicCost = isDefaultAllowed ? ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, count, max) : ERROR(GENERIC);
size_t const repeatCost = *repeatMode != FSE_repeat_none ? ZSTD_fseBitCost(prevCTable, count, max) : ERROR(GENERIC);
size_t const NCountCost = ZSTD_NCountCost(count, max, nbSeq, FSELog);
size_t const compressedCost = (NCountCost << 3) + ZSTD_entropyCost(count, max, nbSeq);
if (isDefaultAllowed) {
assert(!ZSTD_isError(basicCost));
assert(!(*repeatMode == FSE_repeat_valid && ZSTD_isError(repeatCost)));
}
assert(!ZSTD_isError(NCountCost));
assert(compressedCost < ERROR(maxCode));
DEBUGLOG(5, "Estimated bit costs: basic=%u\trepeat=%u\tcompressed=%u",
(U32)basicCost, (U32)repeatCost, (U32)compressedCost);
if (basicCost <= repeatCost && basicCost <= compressedCost) {
DEBUGLOG(5, "Selected set_basic");
assert(isDefaultAllowed);
*repeatMode = FSE_repeat_none;
return set_basic;
}
if (repeatCost <= compressedCost) {
DEBUGLOG(5, "Selected set_repeat");
assert(!ZSTD_isError(repeatCost));
return set_repeat;
}
assert(compressedCost < basicCost && compressedCost < repeatCost);
}
DEBUGLOG(5, "Selected set_compressed");
*repeatMode = FSE_repeat_check;
@ -1803,10 +2007,11 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
const int bmi2)
{
const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
ZSTD_strategy const strategy = cctxParams->cParams.strategy;
U32 count[MaxSeq+1];
FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
U32 LLtype, Offtype, MLtype; /* compressed, raw or rle */
const seqDef* const sequences = seqStorePtr->sequencesStart;
const BYTE* const ofCodeTable = seqStorePtr->ofCode;
@ -1817,6 +2022,7 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
BYTE* op = ostart;
size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
BYTE* seqHead;
BYTE* lastNCount = NULL;
ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
@ -1824,7 +2030,7 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
{ const BYTE* const literals = seqStorePtr->litStart;
size_t const litSize = seqStorePtr->lit - literals;
size_t const cSize = ZSTD_compressLiterals(
prevEntropy, nextEntropy,
&prevEntropy->huf, &nextEntropy->huf,
cctxParams->cParams.strategy, cctxParams->disableLiteralCompression,
op, dstCapacity,
literals, litSize,
@ -1844,13 +2050,9 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
else
op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
if (nbSeq==0) {
memcpy(nextEntropy->litlengthCTable, prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable));
nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
memcpy(nextEntropy->offcodeCTable, prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable));
nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
memcpy(nextEntropy->matchlengthCTable, prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable));
nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
return op - ostart;
/* Copy the old tables over as if we repeated them */
memcpy(&nextEntropy->fse, &prevEntropy->fse, sizeof(prevEntropy->fse));
return op - ostart;
}
/* seqHead : flags for FSE encoding type */
@ -1862,13 +2064,17 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
{ U32 max = MaxLL;
size_t const mostFrequent = FSE_countFast_wksp(count, &max, llCodeTable, nbSeq, workspace);
DEBUGLOG(5, "Building LL table");
nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
LLtype = ZSTD_selectEncodingType(&nextEntropy->litlength_repeatMode, mostFrequent, nbSeq, LL_defaultNormLog, ZSTD_defaultAllowed);
nextEntropy->fse.litlength_repeatMode = prevEntropy->fse.litlength_repeatMode;
LLtype = ZSTD_selectEncodingType(&nextEntropy->fse.litlength_repeatMode, count, max, mostFrequent, nbSeq, LLFSELog, prevEntropy->fse.litlengthCTable, LL_defaultNorm, LL_defaultNormLog, ZSTD_defaultAllowed, strategy);
assert(set_basic < set_compressed && set_rle < set_compressed);
assert(!(LLtype < set_compressed && nextEntropy->fse.litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
count, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable),
prevEntropy->fse.litlengthCTable, sizeof(prevEntropy->fse.litlengthCTable),
workspace, HUF_WORKSPACE_SIZE);
if (ZSTD_isError(countSize)) return countSize;
if (LLtype == set_compressed)
lastNCount = op;
op += countSize;
} }
/* build CTable for Offsets */
@ -1877,26 +2083,32 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
/* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
DEBUGLOG(5, "Building OF table");
nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
Offtype = ZSTD_selectEncodingType(&nextEntropy->offcode_repeatMode, mostFrequent, nbSeq, OF_defaultNormLog, defaultPolicy);
nextEntropy->fse.offcode_repeatMode = prevEntropy->fse.offcode_repeatMode;
Offtype = ZSTD_selectEncodingType(&nextEntropy->fse.offcode_repeatMode, count, max, mostFrequent, nbSeq, OffFSELog, prevEntropy->fse.offcodeCTable, OF_defaultNorm, OF_defaultNormLog, defaultPolicy, strategy);
assert(!(Offtype < set_compressed && nextEntropy->fse.offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
count, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable),
prevEntropy->fse.offcodeCTable, sizeof(prevEntropy->fse.offcodeCTable),
workspace, HUF_WORKSPACE_SIZE);
if (ZSTD_isError(countSize)) return countSize;
if (Offtype == set_compressed)
lastNCount = op;
op += countSize;
} }
/* build CTable for MatchLengths */
{ U32 max = MaxML;
size_t const mostFrequent = FSE_countFast_wksp(count, &max, mlCodeTable, nbSeq, workspace);
DEBUGLOG(5, "Building ML table");
nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
MLtype = ZSTD_selectEncodingType(&nextEntropy->matchlength_repeatMode, mostFrequent, nbSeq, ML_defaultNormLog, ZSTD_defaultAllowed);
nextEntropy->fse.matchlength_repeatMode = prevEntropy->fse.matchlength_repeatMode;
MLtype = ZSTD_selectEncodingType(&nextEntropy->fse.matchlength_repeatMode, count, max, mostFrequent, nbSeq, MLFSELog, prevEntropy->fse.matchlengthCTable, ML_defaultNorm, ML_defaultNormLog, ZSTD_defaultAllowed, strategy);
assert(!(MLtype < set_compressed && nextEntropy->fse.matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
count, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable),
prevEntropy->fse.matchlengthCTable, sizeof(prevEntropy->fse.matchlengthCTable),
workspace, HUF_WORKSPACE_SIZE);
if (ZSTD_isError(countSize)) return countSize;
if (MLtype == set_compressed)
lastNCount = op;
op += countSize;
} }
@ -1911,6 +2123,21 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
longOffsets, bmi2);
if (ZSTD_isError(bitstreamSize)) return bitstreamSize;
op += bitstreamSize;
/* zstd versions <= 1.3.4 mistakenly report corruption when
* FSE_readNCount() recieves a buffer < 4 bytes.
* Fixed by https://github.com/facebook/zstd/pull/1146.
* This can happen when the last set_compressed table present is 2
* bytes and the bitstream is only one byte.
* In this exceedingly rare case, we will simply emit an uncompressed
* block, since it isn't worth optimizing.
*/
if (lastNCount && (op - lastNCount) < 4) {
/* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
assert(op - lastNCount == 3);
DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
"emitting an uncompressed block.");
return 0;
}
}
return op - ostart;
@ -1926,6 +2153,7 @@ MEM_STATIC size_t ZSTD_compressSequences(seqStore_t* seqStorePtr,
size_t const cSize = ZSTD_compressSequences_internal(
seqStorePtr, prevEntropy, nextEntropy, cctxParams, dst, dstCapacity,
workspace, bmi2);
if (cSize == 0) return 0;
/* When srcSize <= dstCapacity, there is enough space to write a raw uncompressed block.
* Since we ran out of space, block must be not compressible, so fall back to raw uncompressed block.
*/
@ -1942,8 +2170,8 @@ MEM_STATIC size_t ZSTD_compressSequences(seqStore_t* seqStorePtr,
* block. After the first block, the offcode table might not have large
* enough codes to represent the offsets in the data.
*/
if (nextEntropy->offcode_repeatMode == FSE_repeat_valid)
nextEntropy->offcode_repeatMode = FSE_repeat_check;
if (nextEntropy->fse.offcode_repeatMode == FSE_repeat_valid)
nextEntropy->fse.offcode_repeatMode = FSE_repeat_check;
return cSize;
}
@ -1951,9 +2179,9 @@ MEM_STATIC size_t ZSTD_compressSequences(seqStore_t* seqStorePtr,
/* ZSTD_selectBlockCompressor() :
* Not static, but internal use only (used by long distance matcher)
* assumption : strat is a valid strategy */
ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict)
ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMode_e dictMode)
{
static const ZSTD_blockCompressor blockCompressor[2][(unsigned)ZSTD_btultra+1] = {
static const ZSTD_blockCompressor blockCompressor[3][(unsigned)ZSTD_btultra+1] = {
{ ZSTD_compressBlock_fast /* default for 0 */,
ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy,
ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2,
@ -1961,13 +2189,19 @@ ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict
{ ZSTD_compressBlock_fast_extDict /* default for 0 */,
ZSTD_compressBlock_fast_extDict, ZSTD_compressBlock_doubleFast_extDict, ZSTD_compressBlock_greedy_extDict,
ZSTD_compressBlock_lazy_extDict,ZSTD_compressBlock_lazy2_extDict, ZSTD_compressBlock_btlazy2_extDict,
ZSTD_compressBlock_btopt_extDict, ZSTD_compressBlock_btultra_extDict }
ZSTD_compressBlock_btopt_extDict, ZSTD_compressBlock_btultra_extDict },
{ ZSTD_compressBlock_fast_dictMatchState /* default for 0 */,
ZSTD_compressBlock_fast_dictMatchState,
NULL, NULL, NULL, NULL, NULL, NULL, NULL /* unimplemented as of yet */ }
};
ZSTD_blockCompressor selectedCompressor;
ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
assert((U32)strat >= (U32)ZSTD_fast);
assert((U32)strat <= (U32)ZSTD_btultra);
return blockCompressor[extDict!=0][(U32)strat];
selectedCompressor = blockCompressor[(int)dictMode][(U32)strat];
assert(selectedCompressor != NULL);
return selectedCompressor;
}
static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
@ -1999,6 +2233,11 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
ZSTD_resetSeqStore(&(zc->seqStore));
ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy; /* required for optimal parser to read stats from dictionary */
/* a gap between an attached dict and the current window is not safe,
* they must remain adjacent, and when that stops being the case, the dict
* must be unset */
assert(ms->dictMatchState == NULL || ms->loadedDictEnd == ms->window.dictLimit);
/* limited update after a very long match */
{ const BYTE* const base = ms->window.base;
const BYTE* const istart = (const BYTE*)src;
@ -2009,7 +2248,7 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
}
/* select and store sequences */
{ U32 const extDict = ZSTD_window_hasExtDict(ms->window);
{ ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
size_t lastLLSize;
{ int i;
for (i = 0; i < ZSTD_REP_NUM; ++i)
@ -2023,7 +2262,7 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
ms, &zc->seqStore,
zc->blockState.nextCBlock->rep,
&zc->appliedParams.cParams,
src, srcSize, extDict);
src, srcSize);
assert(zc->externSeqStore.pos <= zc->externSeqStore.size);
} else if (zc->appliedParams.ldmParams.enableLdm) {
rawSeqStore_t ldmSeqStore = {NULL, 0, 0, 0};
@ -2040,10 +2279,10 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
ms, &zc->seqStore,
zc->blockState.nextCBlock->rep,
&zc->appliedParams.cParams,
src, srcSize, extDict);
src, srcSize);
assert(ldmSeqStore.pos == ldmSeqStore.size);
} else { /* not long range mode */
ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, extDict);
ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, dictMode);
lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, &zc->appliedParams.cParams, src, srcSize);
}
{ const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
@ -2110,8 +2349,9 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
else ms->nextToUpdate -= correction;
ms->loadedDictEnd = 0;
ms->dictMatchState = NULL;
}
ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd);
ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
{ size_t cSize = ZSTD_compressBlock_internal(cctx,
@ -2384,7 +2624,7 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
dictPtr += 4;
{ unsigned maxSymbolValue = 255;
size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.hufCTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.huf.CTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
if (maxSymbolValue < 255) return ERROR(dictionary_corrupted);
dictPtr += hufHeaderSize;
@ -2396,7 +2636,7 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
/* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
/* fill all offset symbols to avoid garbage at end of table */
CHECK_E( FSE_buildCTable_wksp(bs->entropy.offcodeCTable, offcodeNCount, MaxOff, offcodeLog, workspace, HUF_WORKSPACE_SIZE),
CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.offcodeCTable, offcodeNCount, MaxOff, offcodeLog, workspace, HUF_WORKSPACE_SIZE),
dictionary_corrupted);
dictPtr += offcodeHeaderSize;
}
@ -2408,7 +2648,7 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
/* Every match length code must have non-zero probability */
CHECK_F( ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
CHECK_E( FSE_buildCTable_wksp(bs->entropy.matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, workspace, HUF_WORKSPACE_SIZE),
CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, workspace, HUF_WORKSPACE_SIZE),
dictionary_corrupted);
dictPtr += matchlengthHeaderSize;
}
@ -2420,7 +2660,7 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
/* Every literal length code must have non-zero probability */
CHECK_F( ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
CHECK_E( FSE_buildCTable_wksp(bs->entropy.litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, workspace, HUF_WORKSPACE_SIZE),
CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, workspace, HUF_WORKSPACE_SIZE),
dictionary_corrupted);
dictPtr += litlengthHeaderSize;
}
@ -2446,10 +2686,10 @@ static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
if (bs->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
} }
bs->entropy.hufCTable_repeatMode = HUF_repeat_valid;
bs->entropy.offcode_repeatMode = FSE_repeat_valid;
bs->entropy.matchlength_repeatMode = FSE_repeat_valid;
bs->entropy.litlength_repeatMode = FSE_repeat_valid;
bs->entropy.huf.repeatMode = HUF_repeat_valid;
bs->entropy.fse.offcode_repeatMode = FSE_repeat_valid;
bs->entropy.fse.matchlength_repeatMode = FSE_repeat_valid;
bs->entropy.fse.litlength_repeatMode = FSE_repeat_valid;
CHECK_F(ZSTD_loadDictionaryContent(ms, params, dictPtr, dictContentSize, dtlm));
return dictID;
}

48
lib/compress/zstd_compress_internal.h
View File

@ -53,14 +53,22 @@ typedef struct ZSTD_prefixDict_s {
} ZSTD_prefixDict;
typedef struct {
U32 hufCTable[HUF_CTABLE_SIZE_U32(255)];
U32 CTable[HUF_CTABLE_SIZE_U32(255)];
HUF_repeat repeatMode;
} ZSTD_hufCTables_t;
typedef struct {
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)];
HUF_repeat hufCTable_repeatMode;
FSE_repeat offcode_repeatMode;
FSE_repeat matchlength_repeatMode;
FSE_repeat litlength_repeatMode;
} ZSTD_fseCTables_t;
typedef struct {
ZSTD_hufCTables_t huf;
ZSTD_fseCTables_t fse;
} ZSTD_entropyCTables_t;
typedef struct {
@ -114,7 +122,8 @@ typedef struct {
U32 lowLimit; /* below that point, no more data */
} ZSTD_window_t;
typedef struct {
typedef struct ZSTD_matchState_t ZSTD_matchState_t;
struct ZSTD_matchState_t {
ZSTD_window_t window; /* State for window round buffer management */
U32 loadedDictEnd; /* index of end of dictionary */
U32 nextToUpdate; /* index from which to continue table update */
@ -124,7 +133,8 @@ typedef struct {
U32* hashTable3;
U32* chainTable;
optState_t opt; /* optimal parser state */
} ZSTD_matchState_t;
const ZSTD_matchState_t *dictMatchState;
};
typedef struct {
ZSTD_compressedBlockState_t* prevCBlock;
@ -240,10 +250,13 @@ struct ZSTD_CCtx_s {
typedef enum { ZSTD_dtlm_fast, ZSTD_dtlm_full } ZSTD_dictTableLoadMethod_e;
typedef enum { ZSTD_noDict = 0, ZSTD_extDict = 1, ZSTD_dictMatchState = 2 } ZSTD_dictMode_e;
typedef size_t (*ZSTD_blockCompressor) (
ZSTD_matchState_t* bs, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict);
ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMode_e dictMode);
MEM_STATIC U32 ZSTD_LLcode(U32 litLength)
@ -500,6 +513,20 @@ MEM_STATIC U32 ZSTD_window_hasExtDict(ZSTD_window_t const window)
return window.lowLimit < window.dictLimit;
}
/**
* ZSTD_matchState_dictMode():
* Inspects the provided matchState and figures out what dictMode should be
* passed to the compressor.
*/
MEM_STATIC ZSTD_dictMode_e ZSTD_matchState_dictMode(const ZSTD_matchState_t *ms)
{
return ZSTD_window_hasExtDict(ms->window) ?
ZSTD_extDict :
ms->dictMatchState != NULL ?
ZSTD_dictMatchState :
ZSTD_noDict;
}
/**
* ZSTD_window_needOverflowCorrection():
* Returns non-zero if the indices are getting too large and need overflow
@ -567,18 +594,25 @@ MEM_STATIC U32 ZSTD_window_correctOverflow(ZSTD_window_t* window, U32 cycleLog,
* ZSTD_window_enforceMaxDist():
* Updates lowLimit so that:
* (srcEnd - base) - lowLimit == maxDist + loadedDictEnd
*
* This allows a simple check that index >= lowLimit to see if index is valid.
* This must be called before a block compression call, with srcEnd as the block
* source end.
*
* If loadedDictEndPtr is not NULL, we set it to zero once we update lowLimit.
* This is because dictionaries are allowed to be referenced as long as the last
* byte of the dictionary is in the window, but once they are out of range,
* they cannot be referenced. If loadedDictEndPtr is NULL, we use
* loadedDictEnd == 0.
*
* In normal dict mode, the dict is between lowLimit and dictLimit. In
* dictMatchState mode, lowLimit and dictLimit are the same, and the dictionary
* is below them. forceWindow and dictMatchState are therefore incompatible.
*/
MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
void const* srcEnd, U32 maxDist,
U32* loadedDictEndPtr)
U32* loadedDictEndPtr,
const ZSTD_matchState_t** dictMatchStatePtr)
{
U32 const current = (U32)((BYTE const*)srcEnd - window->base);
U32 loadedDictEnd = loadedDictEndPtr != NULL ? *loadedDictEndPtr : 0;
@ -592,6 +626,8 @@ MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
}
if (loadedDictEndPtr)
*loadedDictEndPtr = 0;
if (dictMatchStatePtr)
*dictMatchStatePtr = NULL;
}
}

176
lib/compress/zstd_fast.c
View File

@ -45,26 +45,57 @@ FORCE_INLINE_TEMPLATE
size_t ZSTD_compressBlock_fast_generic(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
void const* src, size_t srcSize,
U32 const hlog, U32 const stepSize, U32 const mls)
U32 const hlog, U32 const stepSize, U32 const mls,
ZSTD_dictMode_e const dictMode)
{
U32* const hashTable = ms->hashTable;
const BYTE* const base = ms->window.base;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = ms->window.dictLimit;
const BYTE* const lowest = base + lowestIndex;
const U32 prefixLowestIndex = ms->window.dictLimit;
const BYTE* const prefixLowest = base + prefixLowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
U32 offset_1=rep[0], offset_2=rep[1];
U32 offsetSaved = 0;
const ZSTD_matchState_t* const dms = ms->dictMatchState;
const U32* const dictHashTable = dictMode == ZSTD_dictMatchState ?
dms->hashTable : NULL;
const U32 dictLowestIndex = dictMode == ZSTD_dictMatchState ?
dms->window.dictLimit : 0;
const BYTE* const dictBase = dictMode == ZSTD_dictMatchState ?
dms->window.base : NULL;
const BYTE* const dictLowest = dictMode == ZSTD_dictMatchState ?
dictBase + dictLowestIndex : NULL;
const BYTE* const dictEnd = dictMode == ZSTD_dictMatchState ?
dms->window.nextSrc : NULL;
const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ?
prefixLowestIndex - (U32)(dictEnd - dictBase) :
0;
const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
/* otherwise, we would get index underflow when translating a dict index
* into a local index */
assert(dictMode != ZSTD_dictMatchState
|| prefixLowestIndex >= (U32)(dictEnd - dictBase));
/* init */
ip += (ip==lowest);
{ U32 const maxRep = (U32)(ip-lowest);
ip += (dictAndPrefixLength == 0);
if (dictMode == ZSTD_noDict) {
U32 const maxRep = (U32)(ip - prefixLowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
if (dictMode == ZSTD_dictMatchState) {
/* dictMatchState repCode checks don't currently handle repCode == 0
* disabling. */
assert(offset_1 <= dictAndPrefixLength);
assert(offset_2 <= dictAndPrefixLength);
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
@ -73,26 +104,62 @@ size_t ZSTD_compressBlock_fast_generic(
U32 const current = (U32)(ip-base);
U32 const matchIndex = hashTable[h];
const BYTE* match = base + matchIndex;
const U32 repIndex = current + 1 - offset_1;
const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
&& repIndex < prefixLowestIndex) ?
dictBase + (repIndex - dictIndexDelta) :
base + repIndex;
hashTable[h] = current; /* update hash table */
if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
if (dictMode == ZSTD_dictMatchState
&& ((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, istart) + 4;
ip++;
ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
} else if ( dictMode == ZSTD_noDict
&& ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
ip++;
ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
if ( (matchIndex <= lowestIndex)
|| (MEM_read32(match) != MEM_read32(ip)) ) {
} else if ( (matchIndex <= prefixLowestIndex)
|| (MEM_read32(match) != MEM_read32(ip)) ) {
if (dictMode == ZSTD_dictMatchState) {
U32 const dictMatchIndex = dictHashTable[h];
const BYTE* dictMatch = dictBase + dictMatchIndex;
if (dictMatchIndex <= dictLowestIndex ||
MEM_read32(dictMatch) != MEM_read32(ip)) {
assert(stepSize >= 1);
ip += ((ip-anchor) >> kSearchStrength) + stepSize;
continue;
} else {
/* found a dict match */
U32 const offset = (U32)(current-dictMatchIndex-dictIndexDelta);
mLength = ZSTD_count_2segments(ip+4, dictMatch+4, iend, dictEnd, istart) + 4;
while (((ip>anchor) & (dictMatch>dictLowest))
&& (ip[-1] == dictMatch[-1])) {
ip--; dictMatch--; mLength++;
} /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
} else {
assert(stepSize >= 1);
ip += ((ip-anchor) >> kSearchStrength) + stepSize;
continue;
}
} else {
/* found a regular match */
U32 const offset = (U32)(ip-match);
mLength = ZSTD_count(ip+4, match+4, iend) + 4;
{ U32 const offset = (U32)(ip-match);
while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} }
while (((ip>anchor) & (match>prefixLowest))
&& (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
/* match found */
ip += mLength;
@ -102,19 +169,43 @@ size_t ZSTD_compressBlock_fast_generic(
/* Fill Table */
hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2; /* here because current+2 could be > iend-8 */
hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
/* check immediate repcode */
while ( (ip <= ilimit)
&& ( (offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
{ U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
hashTable[ZSTD_hashPtr(ip, hlog, mls)] = (U32)(ip-base);
ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
if (dictMode == ZSTD_dictMatchState) {
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?
dictBase - dictIndexDelta + repIndex2 :
base + repIndex2;
if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, istart) + 4;
U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
ip += repLength2;
anchor = ip;
continue;
}
break;
}
}
if (dictMode == ZSTD_noDict) {
while ( (ip <= ilimit)
&& ( (offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */
hashTable[ZSTD_hashPtr(ip, hlog, mls)] = (U32)(ip-base);
ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } } }
/* save reps for next block */
rep[0] = offset_1 ? offset_1 : offsetSaved;
@ -132,17 +223,40 @@ size_t ZSTD_compressBlock_fast(
U32 const hlog = cParams->hashLog;
U32 const mls = cParams->searchLength;
U32 const stepSize = cParams->targetLength;
assert(ms->dictMatchState == NULL);
switch(mls)
{
default: /* includes case 3 */
case 4 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 4);
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 4, ZSTD_noDict);
case 5 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 5);
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 5, ZSTD_noDict);
case 6 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 6);
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 6, ZSTD_noDict);
case 7 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 7);
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 7, ZSTD_noDict);
}
}
size_t ZSTD_compressBlock_fast_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
U32 const hlog = cParams->hashLog;
U32 const mls = cParams->searchLength;
U32 const stepSize = cParams->targetLength;
assert(ms->dictMatchState != NULL);
switch(mls)
{
default: /* includes case 3 */
case 4 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 4, ZSTD_dictMatchState);
case 5 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 5, ZSTD_dictMatchState);
case 6 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 6, ZSTD_dictMatchState);
case 7 :
return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 7, ZSTD_dictMatchState);
}
}

3
lib/compress/zstd_fast.h
View File

@ -24,6 +24,9 @@ void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
size_t ZSTD_compressBlock_fast(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_fast_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_fast_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);

8
lib/compress/zstd_ldm.c
View File

@ -508,7 +508,7 @@ size_t ZSTD_ldm_generateSequences(
* * Try invalidation after the sequence generation and test the
* the offset against maxDist directly.
*/
ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL);
ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL, NULL);
/* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
newLeftoverSize = ZSTD_ldm_generateSequences_internal(
ldmState, sequences, params, chunkStart, chunkSize);
@ -591,12 +591,12 @@ static rawSeq maybeSplitSequence(rawSeqStore_t* rawSeqStore,
size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize,
int const extDict)
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
unsigned const minMatch = cParams->searchLength;
ZSTD_blockCompressor const blockCompressor =
ZSTD_selectBlockCompressor(cParams->strategy, extDict);
ZSTD_selectBlockCompressor(cParams->strategy,
ZSTD_matchState_dictMode(ms));
BYTE const* const base = ms->window.base;
/* Input bounds */
BYTE const* const istart = (BYTE const*)src;

3
lib/compress/zstd_ldm.h
View File

@ -62,8 +62,7 @@ size_t ZSTD_ldm_generateSequences(
size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams,
void const* src, size_t srcSize,
int const extDict);
void const* src, size_t srcSize);
/**
* ZSTD_ldm_skipSequences():

22
lib/compress/zstd_opt.c
View File

@ -39,7 +39,7 @@ static void ZSTD_rescaleFreqs(optState_t* const optPtr,
optPtr->priceType = zop_predef;
assert(optPtr->symbolCosts != NULL);
if (optPtr->symbolCosts->hufCTable_repeatMode == HUF_repeat_valid) { /* huffman table presumed generated by dictionary */
if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) { /* huffman table presumed generated by dictionary */
if (srcSize <= 8192) /* heuristic */
optPtr->priceType = zop_static;
else {
@ -52,7 +52,7 @@ static void ZSTD_rescaleFreqs(optState_t* const optPtr,
{ unsigned lit;
for (lit=0; lit<=MaxLit; lit++) {
U32 const scaleLog = 11; /* scale to 2K */
U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->hufCTable, lit);
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];
@ -60,7 +60,7 @@ static void ZSTD_rescaleFreqs(optState_t* const optPtr,
{ unsigned ll;
FSE_CState_t llstate;
FSE_initCState(&llstate, optPtr->symbolCosts->litlengthCTable);
FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable);
optPtr->litLengthSum = 0;
for (ll=0; ll<=MaxLL; ll++) {
U32 const scaleLog = 10; /* scale to 1K */
@ -72,7 +72,7 @@ static void ZSTD_rescaleFreqs(optState_t* const optPtr,
{ unsigned ml;
FSE_CState_t mlstate;
FSE_initCState(&mlstate, optPtr->symbolCosts->matchlengthCTable);
FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
optPtr->matchLengthSum = 0;
for (ml=0; ml<=MaxML; ml++) {
U32 const scaleLog = 10;
@ -84,7 +84,7 @@ static void ZSTD_rescaleFreqs(optState_t* const optPtr,
{ unsigned of;
FSE_CState_t ofstate;
FSE_initCState(&ofstate, optPtr->symbolCosts->offcodeCTable);
FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable);
optPtr->offCodeSum = 0;
for (of=0; of<=MaxOff; of++) {
U32 const scaleLog = 10;
@ -180,9 +180,9 @@ static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
if (optPtr->priceType == zop_static) {
U32 u, cost;
assert(optPtr->symbolCosts != NULL);
assert(optPtr->symbolCosts->hufCTable_repeatMode == HUF_repeat_valid);
assert(optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid);
for (u=0, cost=0; u < litLength; u++)
cost += HUF_getNbBits(optPtr->symbolCosts->hufCTable, literals[u]);
cost += HUF_getNbBits(optPtr->symbolCosts->huf.CTable, literals[u]);
return cost * BITCOST_MULTIPLIER;
}
@ -202,7 +202,7 @@ static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optP
if (optPtr->priceType == zop_static) {
U32 const llCode = ZSTD_LLcode(litLength);
FSE_CState_t cstate;
FSE_initCState(&cstate, optPtr->symbolCosts->litlengthCTable);
FSE_initCState(&cstate, optPtr->symbolCosts->fse.litlengthCTable);
{ U32 const price = LL_bits[llCode]*BITCOST_MULTIPLIER + BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, llCode);
DEBUGLOG(8, "ZSTD_litLengthPrice: ll=%u, bitCost=%.2f", litLength, (double)price / BITCOST_MULTIPLIER);
return price;
@ -234,7 +234,7 @@ static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* con
if (optPtr->priceType == zop_static) {
U32 const llCode = ZSTD_LLcode(litLength);
FSE_CState_t cstate;
FSE_initCState(&cstate, optPtr->symbolCosts->litlengthCTable);
FSE_initCState(&cstate, optPtr->symbolCosts->fse.litlengthCTable);
return (int)(LL_bits[llCode] * BITCOST_MULTIPLIER)
+ BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, llCode)
- BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, 0);
@ -284,8 +284,8 @@ ZSTD_getMatchPrice(U32 const offset, U32 const matchLength,
if (optPtr->priceType == zop_static) {
U32 const mlCode = ZSTD_MLcode(mlBase);
FSE_CState_t mlstate, offstate;
FSE_initCState(&mlstate, optPtr->symbolCosts->matchlengthCTable);
FSE_initCState(&offstate, optPtr->symbolCosts->offcodeCTable);
FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
FSE_initCState(&offstate, optPtr->symbolCosts->fse.offcodeCTable);
return BITCOST_SYMBOL(offstate.symbolTT, offstate.stateLog, offCode) + offCode*BITCOST_MULTIPLIER
+ BITCOST_SYMBOL(mlstate.symbolTT, mlstate.stateLog, mlCode) + ML_bits[mlCode]*BITCOST_MULTIPLIER;
}