typedef enum { zdss_init=0, zdss_loadHeader,
zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
+
+typedef struct {
+ U32 tableLog;
+ U32 fastMode;
+} ZSTD_seqSymbol_header;
+
+typedef struct {
+ U16 nextState;
+ BYTE nbAdditionalBits;
+ BYTE nbBits;
+ U32 baseValue;
+} ZSTD_seqSymbol;
+
typedef struct {
- FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
- FSE_DTable OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
- FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
+ ZSTD_seqSymbol LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
+ ZSTD_seqSymbol OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
+ ZSTD_seqSymbol MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */
U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
U32 rep[ZSTD_REP_NUM];
struct ZSTD_DCtx_s
{
- const FSE_DTable* LLTptr;
- const FSE_DTable* MLTptr;
- const FSE_DTable* OFTptr;
+ const ZSTD_seqSymbol* LLTptr;
+ const ZSTD_seqSymbol* MLTptr;
+ const ZSTD_seqSymbol* OFTptr;
const HUF_DTable* HUFptr;
ZSTD_entropyDTables_t entropy;
const void* previousDstEnd; /* detect continuity */
{ { 0, 25, 5 } }, { { 0, 24, 5 } },
}; /* OF_defaultDTable */
+
+static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, BYTE symbolValue)
+{
+ void* ptr = dt;
+ ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr;
+ ZSTD_seqSymbol* const cell = dt + 1;
+
+ DTableH->tableLog = 0;
+ DTableH->fastMode = 0;
+
+ cell->nbBits = 0;
+ cell->nextState = 0;
+ cell->nbAdditionalBits = 0;
+ cell->baseValue = symbolValue;
+}
+
+
+/* ZSTD_buildFSETable() :
+ * generate FSE decoding table for one symbol (ll, ml or off) */
+static void
+ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
+ const short* normalizedCounter, unsigned maxSymbolValue,
+ const U32* baseValue, const U32* nbAdditionalBits,
+ unsigned tableLog)
+{
+ ZSTD_seqSymbol* const tableDecode = dt+1;
+ U16 symbolNext[MaxSeq+1];
+
+ U32 const maxSV1 = maxSymbolValue + 1;
+ U32 const tableSize = 1 << tableLog;
+ U32 highThreshold = tableSize-1;
+
+ /* Sanity Checks */
+ assert(maxSymbolValue <= MaxSeq);
+ assert(tableLog <= MaxFSELog);
+
+ /* Init, lay down lowprob symbols */
+ { ZSTD_seqSymbol_header DTableH;
+ DTableH.tableLog = tableLog;
+ DTableH.fastMode = 1;
+ { S16 const largeLimit= (S16)(1 << (tableLog-1));
+ U32 s;
+ for (s=0; s<maxSV1; s++) {
+ if (normalizedCounter[s]==-1) {
+ tableDecode[highThreshold--].baseValue = s;
+ symbolNext[s] = 1;
+ } else {
+ if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
+ symbolNext[s] = normalizedCounter[s];
+ } } }
+ memcpy(dt, &DTableH, sizeof(DTableH));
+ }
+
+ /* Spread symbols */
+ { U32 const tableMask = tableSize-1;
+ U32 const step = FSE_TABLESTEP(tableSize);
+ U32 s, position = 0;
+ for (s=0; s<maxSV1; s++) {
+ int i;
+ for (i=0; i<normalizedCounter[s]; i++) {
+ tableDecode[position].baseValue = s;
+ position = (position + step) & tableMask;
+ while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */
+ } }
+ assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
+ }
+
+ /* Build Decoding table */
+ { U32 u;
+ for (u=0; u<tableSize; u++) {
+ U32 const symbol = tableDecode[u].baseValue;
+ U32 const nextState = symbolNext[symbol]++;
+ tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) );
+ tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
+ assert(nbAdditionalBits[symbol] < 255);
+ tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol];
+ tableDecode[u].baseValue = baseValue[symbol];
+ } }
+}
+
+
/*! ZSTD_buildSeqTable() :
* @return : nb bytes read from src,
- * or an error code if it fails, testable with ZSTD_isError()
- */
-static size_t ZSTD_buildSeqTable(FSE_DTable* DTableSpace, const FSE_DTable** DTablePtr,
+ * or an error code if it fails */
+static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr,
symbolEncodingType_e type, U32 max, U32 maxLog,
const void* src, size_t srcSize,
+ const U32* baseValue, const U32* nbAdditionalBits,
const FSE_decode_t4* defaultTable, U32 flagRepeatTable)
{
switch(type)
case set_rle :
if (!srcSize) return ERROR(srcSize_wrong);
if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected);
- FSE_buildDTable_rle(DTableSpace, *(const BYTE*)src);
+ ZSTD_buildSeqTable_rle(DTableSpace, *(const BYTE*)src);
*DTablePtr = DTableSpace;
return 1;
case set_basic :
+ assert(0); /* need to rebuild all default tables */
*DTablePtr = &defaultTable->dtable;
return 0;
case set_repeat:
size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
if (FSE_isError(headerSize)) return ERROR(corruption_detected);
if (tableLog > maxLog) return ERROR(corruption_detected);
- FSE_buildDTable(DTableSpace, norm, max, tableLog);
+ ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog);
*DTablePtr = DTableSpace;
return headerSize;
} }
}
+static const U32 LL_base[MaxLL+1] = {
+ 0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 18, 20, 22, 24, 28, 32, 40,
+ 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
+ 0x2000, 0x4000, 0x8000, 0x10000 };
+
+static const U32 OF_base[MaxOff+1] = {
+ 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D,
+ 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD,
+ 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
+ 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };
+
+static const U32 OF_bits[MaxOff+1] = {
+ 0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 17, 18, 19, 20, 21, 22, 23,
+ 24, 25, 26, 27, 28, 29, 30, 31 };
+
+static const U32 ML_base[MaxML+1] = {
+ 3, 4, 5, 6, 7, 8, 9, 10,
+ 11, 12, 13, 14, 15, 16, 17, 18,
+ 19, 20, 21, 22, 23, 24, 25, 26,
+ 27, 28, 29, 30, 31, 32, 33, 34,
+ 35, 37, 39, 41, 43, 47, 51, 59,
+ 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
+ 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
+
size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
const void* src, size_t srcSize)
{
/* Build DTables */
{ size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
LLtype, MaxLL, LLFSELog,
- ip, iend-ip, LL_defaultDTable, dctx->fseEntropy);
+ ip, iend-ip,
+ LL_base, LL_bits,
+ LL_defaultDTable, dctx->fseEntropy);
if (ZSTD_isError(llhSize)) return ERROR(corruption_detected);
ip += llhSize;
}
+
{ size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
OFtype, MaxOff, OffFSELog,
- ip, iend-ip, OF_defaultDTable, dctx->fseEntropy);
+ ip, iend-ip,
+ OF_base, OF_bits,
+ OF_defaultDTable, dctx->fseEntropy);
if (ZSTD_isError(ofhSize)) return ERROR(corruption_detected);
ip += ofhSize;
}
+
{ size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
MLtype, MaxML, MLFSELog,
- ip, iend-ip, ML_defaultDTable, dctx->fseEntropy);
+ ip, iend-ip,
+ ML_base, ML_bits,
+ ML_defaultDTable, dctx->fseEntropy);
if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected);
ip += mlhSize;
}
const BYTE* match;
} seq_t;
+typedef struct {
+ size_t state;
+ const ZSTD_seqSymbol* table;
+} ZSTD_fseState;
+
typedef struct {
BIT_DStream_t DStream;
- FSE_DState_t stateLL;
- FSE_DState_t stateOffb;
- FSE_DState_t stateML;
+ ZSTD_fseState stateLL;
+ ZSTD_fseState stateOffb;
+ ZSTD_fseState stateML;
size_t prevOffset[ZSTD_REP_NUM];
const BYTE* prefixStart;
const BYTE* dictEnd;
}
+static void
+ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD)
+{
+ ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state];
+ U32 const nbBits = DInfo.nbBits;
+ size_t const lowBits = BIT_readBits(bitD, nbBits);
+ DStatePtr->state = DInfo.nextState + lowBits;
+}
+
+
typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
/* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum
static seq_t ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
{
seq_t seq;
-
- U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
- U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
- U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= MaxOff, by table construction */
-
- U32 const llBits = LL_bits[llCode];
- U32 const mlBits = ML_bits[mlCode];
- U32 const ofBits = ofCode;
+ U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
+ U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
+ U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
U32 const totalBits = llBits+mlBits+ofBits;
-
- static const U32 LL_base[MaxLL+1] = {
- 0, 1, 2, 3, 4, 5, 6, 7,
- 8, 9, 10, 11, 12, 13, 14, 15,
- 16, 18, 20, 22, 24, 28, 32, 40,
- 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
- 0x2000, 0x4000, 0x8000, 0x10000 };
-
- static const U32 ML_base[MaxML+1] = {
- 3, 4, 5, 6, 7, 8, 9, 10,
- 11, 12, 13, 14, 15, 16, 17, 18,
- 19, 20, 21, 22, 23, 24, 25, 26,
- 27, 28, 29, 30, 31, 32, 33, 34,
- 35, 37, 39, 41, 43, 47, 51, 59,
- 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
- 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
-
- static const U32 OF_base[MaxOff+1] = {
- 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D,
- 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD,
- 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
- 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };
+ U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
+ U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
+ U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
/* sequence */
{ size_t offset;
- if (!ofCode)
+ if (!ofBits)
offset = 0;
else {
ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
assert(ofBits <= MaxOff);
if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed);
- offset = OF_base[ofCode] + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
+ offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
BIT_reloadDStream(&seqState->DStream);
if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32); /* to avoid another reload */
} else {
- offset = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
+ offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
}
}
- if (ofCode <= 1) {
- offset += (llCode==0);
+ if (ofBits <= 1) {
+ offset += (llBase==0);
if (offset) {
size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
seq.offset = offset;
}
- seq.matchLength = ML_base[mlCode]
- + ((mlCode>31) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0); /* <= 16 bits */
+ seq.matchLength = mlBase
+ + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0); /* <= 16 bits */
if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
BIT_reloadDStream(&seqState->DStream);
if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
/* Ensure there are enough bits to read the rest of data in 64-bit mode. */
ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
- seq.litLength = LL_base[llCode]
- + ((llCode>15) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0); /* <= 16 bits */
+ seq.litLength = llBase
+ + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0); /* <= 16 bits */
if (MEM_32bits())
BIT_reloadDStream(&seqState->DStream);
(U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
/* ANS state update */
- FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */
- FSE_updateState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */
+ ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */
+ ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */
if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */
- FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */
+ ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */
return seq;
}
}
+static void
+ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
+{
+ const void* ptr = dt;
+ const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
+ DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
+ DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
+ (U32)DStatePtr->state, DTableH->tableLog);
+ BIT_reloadDStream(bitD);
+ DStatePtr->table = dt + 1;
+}
+
static size_t ZSTD_decompressSequences(
ZSTD_DCtx* dctx,
void* dst, size_t maxDstSize,
dctx->fseEntropy = 1;
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
- FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
- FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
- FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
+ DEBUGLOG(6, "ZSTD_decompressSequences: init stateLL");
+ ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
+ DEBUGLOG(6, "ZSTD_decompressSequences: init stateOffb");
+ ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
+ DEBUGLOG(6, "ZSTD_decompressSequences: init stateML");
+ ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
nbSeq--;
}
+#if 0
+
HINT_INLINE
seq_t ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets)
{
return op-ostart;
}
+#endif
static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
void* dst, size_t dstCapacity,
ip += litCSize;
srcSize -= litCSize;
}
+#if 0
if ( frame /* windowSize exists */
&& (dctx->fParams.windowSize > (1<<24))
&& MEM_64bits() /* x86 benefits less from long mode than x64 */ )
return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, isLongOffset);
+#endif
return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, isLongOffset);
}
U32 offcodeMaxValue = MaxOff, offcodeLog;
size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted);
+ if (offcodeMaxValue > MaxOff) return ERROR(dictionary_corrupted);
if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
- CHECK_E(FSE_buildDTable(entropy->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog), dictionary_corrupted);
+ ZSTD_buildFSETable(entropy->OFTable,
+ offcodeNCount, offcodeMaxValue,
+ OF_base, OF_bits,
+ offcodeLog);
dictPtr += offcodeHeaderSize;
}
unsigned matchlengthMaxValue = MaxML, matchlengthLog;
size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
+ if (matchlengthMaxValue > MaxML) return ERROR(dictionary_corrupted);
if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
- CHECK_E(FSE_buildDTable(entropy->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog), dictionary_corrupted);
+ ZSTD_buildFSETable(entropy->MLTable,
+ matchlengthNCount, matchlengthMaxValue,
+ ML_base, ML_bits,
+ matchlengthLog);
dictPtr += matchlengthHeaderSize;
}
unsigned litlengthMaxValue = MaxLL, litlengthLog;
size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
+ if (litlengthMaxValue > MaxLL) return ERROR(dictionary_corrupted);
if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
- CHECK_E(FSE_buildDTable(entropy->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog), dictionary_corrupted);
+ ZSTD_buildFSETable(entropy->LLTable,
+ litlengthNCount, litlengthMaxValue,
+ LL_base, LL_bits,
+ litlengthLog);
dictPtr += litlengthHeaderSize;
}