ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

refactored compression code

Browse Source
This commit is contained in:
Yann Collet
2015-11-11 21:38:21 +01:00
parent 438abef903
commit 14983e7aed
3 changed files with 547 additions and 572 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/zstd_decompress.c
+12 -353
View File
@@ -33,14 +33,6 @@
/* ***************************************************************
* Tuning parameters
*****************************************************************/
/*!
* MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
* Increasing memory usage improves compression ratio
* Reduced memory usage can improve speed, due to cache effect
*/
#define ZSTD_MEMORY_USAGE 16
/*!
* HEAPMODE :
* Select how default compression functions will allocate memory for their hash table,
@@ -53,7 +45,7 @@
/*!
* LEGACY_SUPPORT :
* decompressor can decode older formats (starting from Zstd 0.1+)
* ZSTD_decompress() can decode older formats (starting from zstd 0.1+)
*/
#ifndef ZSTD_LEGACY_SUPPORT
# define ZSTD_LEGACY_SUPPORT 1
@@ -80,10 +72,6 @@
/* *******************************************************
* Compiler specifics
*********************************************************/
#ifdef __AVX2__
# include <immintrin.h> /* AVX2 intrinsics */
#endif
#ifdef _MSC_VER /* Visual Studio */
# define FORCE_INLINE static __forceinline
# include <intrin.h> /* For Visual 2005 */
@@ -99,43 +87,14 @@
#endif
/* *******************************************************
* Constants
*********************************************************/
#define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
#define HASH_TABLESIZE (1 << HASH_LOG)
#define HASH_MASK (HASH_TABLESIZE - 1)
#define KNUTH 2654435761
#define BIT7 128
#define BIT6 64
#define BIT5 32
#define BIT4 16
#define BIT1 2
#define BIT0 1
#define KB *(1 <<10)
#define MB *(1 <<20)
#define GB *(1U<<30)
#define BLOCKSIZE (128 KB) /* define, for static allocation */
#define IS_RAW BIT0
#define IS_RLE BIT1
#define MINMATCH 4
#define LitFSELog 11
#define MLFSELog 10
#define LLFSELog 10
#define OffFSELog 9
#define MAX(a,b) ((a)<(b)?(b):(a))
#define MaxSeq MAX(MaxLL, MaxML)
#define LITERAL_NOENTROPY 63
#define COMMAND_NOENTROPY 7 /* to remove */
static const size_t ZSTD_blockHeaderSize = 3;
static const size_t ZSTD_frameHeaderSize = 4;
/* *************************************
* Local types
***************************************/
typedef struct
{
blockType_t blockType;
U32 origSize;
} blockProperties_t;
/* *******************************************************
@@ -144,22 +103,11 @@ static const size_t ZSTD_frameHeaderSize = 4;
static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
/* **************************************
* Local structures
****************************************/
void ZSTD_resetSeqStore(seqStore_t* ssPtr)
{
ssPtr->offset = ssPtr->offsetStart;
ssPtr->lit = ssPtr->litStart;
ssPtr->litLength = ssPtr->litLengthStart;
ssPtr->matchLength = ssPtr->matchLengthStart;
ssPtr->dumps = ssPtr->dumpsStart;
}
/* *************************************
* Error Management
***************************************/
unsigned ZSTD_versionNumber (void) { return ZSTD_VERSION_NUMBER; }
/*! ZSTD_isError
* tells if a return value is an error code */
unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
@@ -169,295 +117,6 @@ unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
/* *************************************
* Tool functions
***************************************/
unsigned ZSTD_versionNumber (void) { return ZSTD_VERSION_NUMBER; }
/* *******************************************************
* Compression
*********************************************************/
size_t ZSTD_compressBound(size_t srcSize) /* maximum compressed size */
{
return FSE_compressBound(srcSize) + 12;
}
size_t ZSTD_noCompressBlock (void* dst, size_t maxDstSize, const void* src, size_t srcSize)
{
BYTE* const ostart = (BYTE* const)dst;
if (srcSize + ZSTD_blockHeaderSize > maxDstSize) return ERROR(dstSize_tooSmall);
memcpy(ostart + ZSTD_blockHeaderSize, src, srcSize);
/* Build header */
ostart[0] = (BYTE)(srcSize>>16);
ostart[1] = (BYTE)(srcSize>>8);
ostart[2] = (BYTE) srcSize;
ostart[0] += (BYTE)(bt_raw<<6); /* is a raw (uncompressed) block */
return ZSTD_blockHeaderSize+srcSize;
}
static size_t ZSTD_compressRawLiteralsBlock (void* dst, size_t maxDstSize, const void* src, size_t srcSize)
{
BYTE* const ostart = (BYTE* const)dst;
if (srcSize + 3 > maxDstSize) return ERROR(dstSize_tooSmall);
MEM_writeLE32(dst, ((U32)srcSize << 2) | IS_RAW);
memcpy(ostart + 3, src, srcSize);
return srcSize + 3;
}
static size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t maxDstSize, const void* src, size_t srcSize)
{
BYTE* const ostart = (BYTE* const)dst;
(void)maxDstSize;
MEM_writeLE32(dst, ((U32)srcSize << 2) | IS_RLE); /* note : maxDstSize > litHeaderSize > 4 */
ostart[3] = *(const BYTE*)src;
return 4;
}
size_t ZSTD_minGain(size_t srcSize) { return (srcSize >> 6) + 1; }
static size_t ZSTD_compressLiterals (void* dst, size_t maxDstSize,
const void* src, size_t srcSize)
{
const size_t minGain = ZSTD_minGain(srcSize);
BYTE* const ostart = (BYTE*)dst;
size_t hsize;
static const size_t litHeaderSize = 5;
if (maxDstSize < litHeaderSize+1) return ERROR(dstSize_tooSmall); /* not enough space for compression */
hsize = HUF_compress(ostart+litHeaderSize, maxDstSize-litHeaderSize, src, srcSize);
if ((hsize==0) || (hsize >= srcSize - minGain)) return ZSTD_compressRawLiteralsBlock(dst, maxDstSize, src, srcSize);
if (hsize==1) return ZSTD_compressRleLiteralsBlock(dst, maxDstSize, src, srcSize);
/* Build header */
{
ostart[0] = (BYTE)(srcSize << 2); /* is a block, is compressed */
ostart[1] = (BYTE)(srcSize >> 6);
ostart[2] = (BYTE)(srcSize >>14);
ostart[2] += (BYTE)(hsize << 5);
ostart[3] = (BYTE)(hsize >> 3);
ostart[4] = (BYTE)(hsize >>11);
}
return hsize+litHeaderSize;
}
size_t ZSTD_compressSequences(BYTE* dst, size_t maxDstSize,
const seqStore_t* seqStorePtr,
size_t srcSize)
{
U32 count[MaxSeq+1];
S16 norm[MaxSeq+1];
size_t mostFrequent;
U32 max = 255;
U32 tableLog = 11;
U32 CTable_LitLength [FSE_CTABLE_SIZE_U32(LLFSELog, MaxLL )];
U32 CTable_OffsetBits [FSE_CTABLE_SIZE_U32(OffFSELog,MaxOff)];
U32 CTable_MatchLength[FSE_CTABLE_SIZE_U32(MLFSELog, MaxML )];
U32 LLtype, Offtype, MLtype; /* compressed, raw or rle */
const BYTE* const op_lit_start = seqStorePtr->litStart;
const BYTE* const llTable = seqStorePtr->litLengthStart;
const BYTE* const llPtr = seqStorePtr->litLength;
const BYTE* const mlTable = seqStorePtr->matchLengthStart;
const U32* const offsetTable = seqStorePtr->offsetStart;
BYTE* const offCodeTable = seqStorePtr->offCodeStart;
BYTE* op = dst;
BYTE* const oend = dst + maxDstSize;
const size_t nbSeq = llPtr - llTable;
const size_t minGain = ZSTD_minGain(srcSize);
const size_t maxCSize = srcSize - minGain;
BYTE* seqHead;
/* Compress literals */
{
size_t cSize;
size_t litSize = seqStorePtr->lit - op_lit_start;
if (litSize <= LITERAL_NOENTROPY)
cSize = ZSTD_compressRawLiteralsBlock(op, maxDstSize, op_lit_start, litSize);
else
cSize = ZSTD_compressLiterals(op, maxDstSize, op_lit_start, litSize);
if (ZSTD_isError(cSize)) return cSize;
op += cSize;
}
/* Sequences Header */
if ((oend-op) < MIN_SEQUENCES_SIZE)
return ERROR(dstSize_tooSmall);
MEM_writeLE16(op, (U16)nbSeq); op+=2;
seqHead = op;
/* dumps : contains too large lengths */
{
size_t dumpsLength = seqStorePtr->dumps - seqStorePtr->dumpsStart;
if (dumpsLength < 512)
{
op[0] = (BYTE)(dumpsLength >> 8);
op[1] = (BYTE)(dumpsLength);
op += 2;
}
else
{
op[0] = 2;
op[1] = (BYTE)(dumpsLength>>8);
op[2] = (BYTE)(dumpsLength);
op += 3;
}
if ((size_t)(oend-op) < dumpsLength+6) return ERROR(dstSize_tooSmall);
memcpy(op, seqStorePtr->dumpsStart, dumpsLength);
op += dumpsLength;
}
/* CTable for Literal Lengths */
max = MaxLL;
mostFrequent = FSE_countFast(count, &max, seqStorePtr->litLengthStart, nbSeq);
if ((mostFrequent == nbSeq) && (nbSeq > 2))
{
*op++ = *(seqStorePtr->litLengthStart);
FSE_buildCTable_rle(CTable_LitLength, (BYTE)max);
LLtype = bt_rle;
}
else if ((nbSeq < 64) || (mostFrequent < (nbSeq >> (LLbits-1))))
{
FSE_buildCTable_raw(CTable_LitLength, LLbits);
LLtype = bt_raw;
}
else
{
size_t NCountSize;
tableLog = FSE_optimalTableLog(LLFSELog, nbSeq, max);
FSE_normalizeCount(norm, tableLog, count, nbSeq, max);
NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return ERROR(GENERIC);
op += NCountSize;
FSE_buildCTable(CTable_LitLength, norm, max, tableLog);
LLtype = bt_compressed;
}
/* CTable for Offsets codes */
{
/* create Offset codes */
size_t i;
max = MaxOff;
for (i=0; i<nbSeq; i++)
{
offCodeTable[i] = (BYTE)ZSTD_highbit(offsetTable[i]) + 1;
if (offsetTable[i]==0) offCodeTable[i]=0;
}
mostFrequent = FSE_countFast(count, &max, offCodeTable, nbSeq);
}
if ((mostFrequent == nbSeq) && (nbSeq > 2))
{
*op++ = *offCodeTable;
FSE_buildCTable_rle(CTable_OffsetBits, (BYTE)max);
Offtype = bt_rle;
}
else if ((nbSeq < 64) || (mostFrequent < (nbSeq >> (Offbits-1))))
{
FSE_buildCTable_raw(CTable_OffsetBits, Offbits);
Offtype = bt_raw;
}
else
{
size_t NCountSize;
tableLog = FSE_optimalTableLog(OffFSELog, nbSeq, max);
FSE_normalizeCount(norm, tableLog, count, nbSeq, max);
NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return ERROR(GENERIC);
op += NCountSize;
FSE_buildCTable(CTable_OffsetBits, norm, max, tableLog);
Offtype = bt_compressed;
}
/* CTable for MatchLengths */
max = MaxML;
mostFrequent = FSE_countFast(count, &max, seqStorePtr->matchLengthStart, nbSeq);
if ((mostFrequent == nbSeq) && (nbSeq > 2))
{
*op++ = *seqStorePtr->matchLengthStart;
FSE_buildCTable_rle(CTable_MatchLength, (BYTE)max);
MLtype = bt_rle;
}
else if ((nbSeq < 64) || (mostFrequent < (nbSeq >> (MLbits-1))))
{
FSE_buildCTable_raw(CTable_MatchLength, MLbits);
MLtype = bt_raw;
}
else
{
size_t NCountSize;
tableLog = FSE_optimalTableLog(MLFSELog, nbSeq, max);
FSE_normalizeCount(norm, tableLog, count, nbSeq, max);
NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return ERROR(GENERIC);
op += NCountSize;
FSE_buildCTable(CTable_MatchLength, norm, max, tableLog);
MLtype = bt_compressed;
}
seqHead[0] += (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
/* Encoding Sequences */
{
size_t streamSize, errorCode;
BIT_CStream_t blockStream;
FSE_CState_t stateMatchLength;
FSE_CState_t stateOffsetBits;
FSE_CState_t stateLitLength;
int i;
errorCode = BIT_initCStream(&blockStream, op, oend-op);
if (ERR_isError(errorCode)) return ERROR(dstSize_tooSmall); /* not enough space remaining */
FSE_initCState(&stateMatchLength, CTable_MatchLength);
FSE_initCState(&stateOffsetBits, CTable_OffsetBits);
FSE_initCState(&stateLitLength, CTable_LitLength);
for (i=(int)nbSeq-1; i>=0; i--)
{
BYTE matchLength = mlTable[i];
U32 offset = offsetTable[i];
BYTE offCode = offCodeTable[i]; /* 32b*/ /* 64b*/
U32 nbBits = (offCode-1) * (!!offCode);
BYTE litLength = llTable[i]; /* (7)*/ /* (7)*/
FSE_encodeSymbol(&blockStream, &stateMatchLength, matchLength); /* 17 */ /* 17 */
if (MEM_32bits()) BIT_flushBits(&blockStream); /* 7 */
BIT_addBits(&blockStream, offset, nbBits); /* 32 */ /* 42 */
if (MEM_32bits()) BIT_flushBits(&blockStream); /* 7 */
FSE_encodeSymbol(&blockStream, &stateOffsetBits, offCode); /* 16 */ /* 51 */
FSE_encodeSymbol(&blockStream, &stateLitLength, litLength); /* 26 */ /* 61 */
BIT_flushBits(&blockStream); /* 7 */ /* 7 */
}
FSE_flushCState(&blockStream, &stateMatchLength);
FSE_flushCState(&blockStream, &stateOffsetBits);
FSE_flushCState(&blockStream, &stateLitLength);
streamSize = BIT_closeCStream(&blockStream);
if (streamSize==0) return ERROR(dstSize_tooSmall); /* not enough space */
op += streamSize;
}
/* check compressibility */
if ((size_t)(op-dst) >= maxCSize) return 0;
return op - dst;
}
/* *************************************************************
* Decompression section
***************************************************************/
@@ -526,7 +185,7 @@ static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
/** ZSTD_decodeLiteralsBlock
@return : nb of bytes read from src (< srcSize )*/
@return : nb of bytes read from src (< srcSize ) */
size_t ZSTD_decodeLiteralsBlock(void* ctx,
const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
{