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Split parsers out of zstd_compress.c

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Nick Terrell
2017-09-01 18:28:35 -07:00
parent e7615bacc3
commit 721726d688
10 changed files with 2679 additions and 2527 deletions
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1609
lib/compress/zstd_compress.c
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lib/compress/zstd_compress.h Normal file
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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#ifndef ZSTD_COMPRESS_H
#define ZSTD_COMPRESS_H
/*-*************************************
* Dependencies
***************************************/
#include "zstd_internal.h"
#include "zstdmt_compress.h"
#if defined (__cplusplus)
extern "C" {
#endif
/*-*************************************
* Constants
***************************************/
static const U32 g_searchStrength = 8;
#define HASH_READ_SIZE 8
/*-*************************************
* Context memory management
***************************************/
typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
typedef enum { zcss_init=0, zcss_load, zcss_flush } ZSTD_cStreamStage;
typedef struct ZSTD_prefixDict_s {
const void* dict;
size_t dictSize;
ZSTD_dictMode_e dictMode;
} ZSTD_prefixDict;
struct ZSTD_CCtx_s {
const BYTE* nextSrc; /* next block here to continue on current prefix */
const BYTE* base; /* All regular indexes relative to this position */
const BYTE* dictBase; /* extDict indexes relative to this position */
U32 dictLimit; /* below that point, need extDict */
U32 lowLimit; /* below that point, no more data */
U32 nextToUpdate; /* index from which to continue dictionary update */
U32 nextToUpdate3; /* index from which to continue dictionary update */
U32 hashLog3; /* dispatch table : larger == faster, more memory */
U32 loadedDictEnd; /* index of end of dictionary */
ZSTD_compressionStage_e stage;
U32 dictID;
ZSTD_CCtx_params requestedParams;
ZSTD_CCtx_params appliedParams;
void* workSpace;
size_t workSpaceSize;
size_t blockSize;
U64 pledgedSrcSizePlusOne; /* this way, 0 (default) == unknown */
U64 consumedSrcSize;
XXH64_state_t xxhState;
ZSTD_customMem customMem;
size_t staticSize;
seqStore_t seqStore; /* sequences storage ptrs */
optState_t optState;
U32* hashTable;
U32* hashTable3;
U32* chainTable;
ZSTD_entropyCTables_t* entropy;
/* streaming */
char* inBuff;
size_t inBuffSize;
size_t inToCompress;
size_t inBuffPos;
size_t inBuffTarget;
char* outBuff;
size_t outBuffSize;
size_t outBuffContentSize;
size_t outBuffFlushedSize;
ZSTD_cStreamStage streamStage;
U32 frameEnded;
/* Dictionary */
ZSTD_CDict* cdictLocal;
const ZSTD_CDict* cdict;
ZSTD_prefixDict prefixDict; /* single-usage dictionary */
/* Multi-threading */
ZSTDMT_CCtx* mtctx;
};
static const BYTE LL_Code[64] = { 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 16, 17, 17, 18, 18, 19, 19,
20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24 };
static const BYTE ML_Code[128] = { 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,
32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 37, 37, 37, 37,
38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39,
40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
/*! ZSTD_storeSeq() :
Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
`offsetCode` : distance to match, or 0 == repCode.
`matchCode` : matchLength - MINMATCH
*/
MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t matchCode)
{
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 6)
static const BYTE* g_start = NULL;
U32 const pos = (U32)((const BYTE*)literals - g_start);
if (g_start==NULL) g_start = (const BYTE*)literals;
if ((pos > 0) && (pos < 1000000000))
DEBUGLOG(6, "Cpos %6u :%5u literals & match %3u bytes at distance %6u",
pos, (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
#endif
/* copy Literals */
assert(seqStorePtr->lit + litLength <= seqStorePtr->litStart + 128 KB);
ZSTD_wildcopy(seqStorePtr->lit, literals, litLength);
seqStorePtr->lit += litLength;
/* literal Length */
if (litLength>0xFFFF) {
seqStorePtr->longLengthID = 1;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
}
seqStorePtr->sequences[0].litLength = (U16)litLength;
/* match offset */
seqStorePtr->sequences[0].offset = offsetCode + 1;
/* match Length */
if (matchCode>0xFFFF) {
seqStorePtr->longLengthID = 2;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
}
seqStorePtr->sequences[0].matchLength = (U16)matchCode;
seqStorePtr->sequences++;
}
/*-*************************************
* Match length counter
***************************************/
static unsigned ZSTD_NbCommonBytes (register size_t val)
{
if (MEM_isLittleEndian()) {
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanForward64( &r, (U64)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctzll((U64)val) >> 3);
# else
static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2,
0, 3, 1, 3, 1, 4, 2, 7,
0, 2, 3, 6, 1, 5, 3, 5,
1, 3, 4, 4, 2, 5, 6, 7,
7, 0, 1, 2, 3, 3, 4, 6,
2, 6, 5, 5, 3, 4, 5, 6,
7, 1, 2, 4, 6, 4, 4, 5,
7, 2, 6, 5, 7, 6, 7, 7 };
return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
# endif
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r=0;
_BitScanForward( &r, (U32)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctz((U32)val) >> 3);
# else
static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0,
3, 2, 2, 1, 3, 2, 0, 1,
3, 3, 1, 2, 2, 2, 2, 0,
3, 1, 2, 0, 1, 0, 1, 1 };
return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
# endif
}
} else { /* Big Endian CPU */
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanReverse64( &r, val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clzll(val) >> 3);
# else
unsigned r;
const unsigned n32 = sizeof(size_t)*4; /* calculate this way due to compiler complaining in 32-bits mode */
if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
r += (!val);
return r;
# endif
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r = 0;
_BitScanReverse( &r, (unsigned long)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clz((U32)val) >> 3);
# else
unsigned r;
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
r += (!val);
return r;
# endif
} }
}
MEM_STATIC size_t ZSTD_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* const pInLimit)
{
const BYTE* const pStart = pIn;
const BYTE* const pInLoopLimit = pInLimit - (sizeof(size_t)-1);
while (pIn < pInLoopLimit) {
size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
if (!diff) { pIn+=sizeof(size_t); pMatch+=sizeof(size_t); continue; }
pIn += ZSTD_NbCommonBytes(diff);
return (size_t)(pIn - pStart);
}
if (MEM_64bits()) if ((pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
if ((pIn<(pInLimit-1)) && (MEM_read16(pMatch) == MEM_read16(pIn))) { pIn+=2; pMatch+=2; }
if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
return (size_t)(pIn - pStart);
}
/** ZSTD_count_2segments() :
* can count match length with `ip` & `match` in 2 different segments.
* convention : on reaching mEnd, match count continue starting from iStart
*/
MEM_STATIC size_t ZSTD_count_2segments(const BYTE* ip, const BYTE* match, const BYTE* iEnd, const BYTE* mEnd, const BYTE* iStart)
{
const BYTE* const vEnd = MIN( ip + (mEnd - match), iEnd);
size_t const matchLength = ZSTD_count(ip, match, vEnd);
if (match + matchLength != mEnd) return matchLength;
return matchLength + ZSTD_count(ip+matchLength, iStart, iEnd);
}
/*-*************************************
* Hashes
***************************************/
static const U32 prime3bytes = 506832829U;
static U32 ZSTD_hash3(U32 u, U32 h) { return ((u << (32-24)) * prime3bytes) >> (32-h) ; }
MEM_STATIC size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_readLE32(ptr), h); } /* only in zstd_opt.h */
static const U32 prime4bytes = 2654435761U;
static U32 ZSTD_hash4(U32 u, U32 h) { return (u * prime4bytes) >> (32-h) ; }
static size_t ZSTD_hash4Ptr(const void* ptr, U32 h) { return ZSTD_hash4(MEM_read32(ptr), h); }
static const U64 prime5bytes = 889523592379ULL;
static size_t ZSTD_hash5(U64 u, U32 h) { return (size_t)(((u << (64-40)) * prime5bytes) >> (64-h)) ; }
static size_t ZSTD_hash5Ptr(const void* p, U32 h) { return ZSTD_hash5(MEM_readLE64(p), h); }
static const U64 prime6bytes = 227718039650203ULL;
static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * prime6bytes) >> (64-h)) ; }
static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
static const U64 prime7bytes = 58295818150454627ULL;
static size_t ZSTD_hash7(U64 u, U32 h) { return (size_t)(((u << (64-56)) * prime7bytes) >> (64-h)) ; }
static size_t ZSTD_hash7Ptr(const void* p, U32 h) { return ZSTD_hash7(MEM_readLE64(p), h); }
static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
MEM_STATIC size_t ZSTD_hashPtr(const void* p, U32 hBits, U32 mls)
{
switch(mls)
{
default:
case 4: return ZSTD_hash4Ptr(p, hBits);
case 5: return ZSTD_hash5Ptr(p, hBits);
case 6: return ZSTD_hash6Ptr(p, hBits);
case 7: return ZSTD_hash7Ptr(p, hBits);
case 8: return ZSTD_hash8Ptr(p, hBits);
}
}
#if defined (__cplusplus)
}
#endif
#endif /* ZSTD_COMPRESS_H */

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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#include "zstd_double_fast.h"
void ZSTD_fillDoubleHashTable(ZSTD_CCtx* cctx, const void* end, const U32 mls)
{
U32* const hashLarge = cctx->hashTable;
U32 const hBitsL = cctx->appliedParams.cParams.hashLog;
U32* const hashSmall = cctx->chainTable;
U32 const hBitsS = cctx->appliedParams.cParams.chainLog;
const BYTE* const base = cctx->base;
const BYTE* ip = base + cctx->nextToUpdate;
const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
const size_t fastHashFillStep = 3;
while(ip <= iend) {
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip - base);
hashLarge[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip - base);
ip += fastHashFillStep;
}
}
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_doubleFast_generic(ZSTD_CCtx* cctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashLong = cctx->hashTable;
const U32 hBitsL = cctx->appliedParams.cParams.hashLog;
U32* const hashSmall = cctx->chainTable;
const U32 hBitsS = cctx->appliedParams.cParams.chainLog;
seqStore_t* seqStorePtr = &(cctx->seqStore);
const BYTE* const base = cctx->base;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = cctx->dictLimit;
const BYTE* const lowest = base + lowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
U32 offset_1=seqStorePtr->rep[0], offset_2=seqStorePtr->rep[1];
U32 offsetSaved = 0;
/* init */
ip += (ip==lowest);
{ U32 const maxRep = (U32)(ip-lowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
size_t mLength;
size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
U32 const current = (U32)(ip-base);
U32 const matchIndexL = hashLong[h2];
U32 const matchIndexS = hashSmall[h];
const BYTE* matchLong = base + matchIndexL;
const BYTE* match = base + matchIndexS;
hashLong[h2] = hashSmall[h] = current; /* update hash tables */
assert(offset_1 <= current); /* supposed guaranteed by construction */
if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
/* favor repcode */
mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
U32 offset;
if ( (matchIndexL > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip)) ) {
mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
offset = (U32)(ip-matchLong);
while (((ip>anchor) & (matchLong>lowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
} else if ( (matchIndexS > lowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) {
size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
U32 const matchIndexL3 = hashLong[hl3];
const BYTE* matchL3 = base + matchIndexL3;
hashLong[hl3] = current + 1;
if ( (matchIndexL3 > lowestIndex) && (MEM_read64(matchL3) == MEM_read64(ip+1)) ) {
mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
ip++;
offset = (U32)(ip-matchL3);
while (((ip>anchor) & (matchL3>lowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
} else {
mLength = ZSTD_count(ip+4, match+4, iend) + 4;
offset = (U32)(ip-match);
while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
}
} else {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
/* match found */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] =
hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2; /* here because current+2 could be > iend-8 */
hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] =
hashSmall[ZSTD_hashPtr(ip-2, hBitsS, 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 */
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
/* save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
seqStorePtr->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
const U32 mls = ctx->appliedParams.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 7); return;
}
}
static void ZSTD_compressBlock_doubleFast_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashLong = ctx->hashTable;
U32 const hBitsL = ctx->appliedParams.cParams.hashLog;
U32* const hashSmall = ctx->chainTable;
U32 const hBitsS = ctx->appliedParams.cParams.chainLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const dictStart = dictBase + lowestIndex;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const lowPrefixPtr = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
U32 offset_1=seqStorePtr->rep[0], offset_2=seqStorePtr->rep[1];
/* Search Loop */
while (ip < ilimit) { /* < instead of <=, because (ip+1) */
const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
const U32 matchIndex = hashSmall[hSmall];
const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
const BYTE* match = matchBase + matchIndex;
const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
const U32 matchLongIndex = hashLong[hLong];
const BYTE* matchLongBase = matchLongIndex < dictLimit ? dictBase : base;
const BYTE* matchLong = matchLongBase + matchLongIndex;
const U32 current = (U32)(ip-base);
const U32 repIndex = current + 1 - offset_1; /* offset_1 expected <= current +1 */
const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* repMatch = repBase + repIndex;
size_t mLength;
hashSmall[hSmall] = hashLong[hLong] = current; /* update hash table */
if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
if ((matchLongIndex > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
const BYTE* matchEnd = matchLongIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchLongIndex < dictLimit ? dictStart : lowPrefixPtr;
U32 offset;
mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, lowPrefixPtr) + 8;
offset = current - matchLongIndex;
while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else if ((matchIndex > lowestIndex) && (MEM_read32(match) == MEM_read32(ip))) {
size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
U32 const matchIndex3 = hashLong[h3];
const BYTE* const match3Base = matchIndex3 < dictLimit ? dictBase : base;
const BYTE* match3 = match3Base + matchIndex3;
U32 offset;
hashLong[h3] = current + 1;
if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
const BYTE* matchEnd = matchIndex3 < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex3 < dictLimit ? dictStart : lowPrefixPtr;
mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, lowPrefixPtr) + 8;
ip++;
offset = current+1 - matchIndex3;
while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
} else {
const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4;
offset = current - matchIndex;
while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
}
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
} }
/* found a match : store it */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2;
hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = current+2;
hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
/* check immediate repcode */
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex)) /* intentional overflow */
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, lowPrefixPtr) + 4;
U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, repLength2-MINMATCH);
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
ip += repLength2;
anchor = ip;
continue;
}
break;
} } }
/* save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1; seqStorePtr->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
U32 const mls = ctx->appliedParams.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 7); return;
}
}

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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#ifndef ZSTD_DOUBLE_FAST_H
#define ZSTD_DOUBLE_FAST_H
#include "zstd_compress.h"
#if defined (__cplusplus)
extern "C" {
#endif
void ZSTD_fillDoubleHashTable(ZSTD_CCtx* cctx, const void* end, const U32 mls);
void ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
#if defined (__cplusplus)
}
#endif
#endif /* ZSTD_DOUBLE_FAST_H */

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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#include "zstd_fast.h"
void ZSTD_fillHashTable (ZSTD_CCtx* zc, const void* end, const U32 mls)
{
U32* const hashTable = zc->hashTable;
U32 const hBits = zc->appliedParams.cParams.hashLog;
const BYTE* const base = zc->base;
const BYTE* ip = base + zc->nextToUpdate;
const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
const size_t fastHashFillStep = 3;
while(ip <= iend) {
hashTable[ZSTD_hashPtr(ip, hBits, mls)] = (U32)(ip - base);
ip += fastHashFillStep;
}
}
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_fast_generic(ZSTD_CCtx* cctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashTable = cctx->hashTable;
U32 const hBits = cctx->appliedParams.cParams.hashLog;
seqStore_t* seqStorePtr = &(cctx->seqStore);
const BYTE* const base = cctx->base;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = cctx->dictLimit;
const BYTE* const lowest = base + lowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
U32 offset_1=seqStorePtr->rep[0], offset_2=seqStorePtr->rep[1];
U32 offsetSaved = 0;
/* init */
ip += (ip==lowest);
{ U32 const maxRep = (U32)(ip-lowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
size_t mLength;
size_t const h = ZSTD_hashPtr(ip, hBits, mls);
U32 const current = (U32)(ip-base);
U32 const matchIndex = hashTable[h];
const BYTE* match = base + matchIndex;
hashTable[h] = current; /* update hash table */
if ((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(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
U32 offset;
if ( (matchIndex <= lowestIndex) || (MEM_read32(match) != MEM_read32(ip)) ) {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
mLength = ZSTD_count(ip+4, match+4, iend) + 4;
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(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
/* match found */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2; /* here because current+2 could be > iend-8 */
hashTable[ZSTD_hashPtr(ip-2, hBits, 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, hBits, mls)] = (U32)(ip-base);
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
/* save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
seqStorePtr->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_fast(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
const U32 mls = ctx->appliedParams.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 7); return;
}
}
static void ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* hashTable = ctx->hashTable;
const U32 hBits = ctx->appliedParams.cParams.hashLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const dictStart = dictBase + lowestIndex;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const lowPrefixPtr = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
U32 offset_1=seqStorePtr->rep[0], offset_2=seqStorePtr->rep[1];
/* Search Loop */
while (ip < ilimit) { /* < instead of <=, because (ip+1) */
const size_t h = ZSTD_hashPtr(ip, hBits, mls);
const U32 matchIndex = hashTable[h];
const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
const BYTE* match = matchBase + matchIndex;
const U32 current = (U32)(ip-base);
const U32 repIndex = current + 1 - offset_1; /* offset_1 expected <= current +1 */
const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* repMatch = repBase + repIndex;
size_t mLength;
hashTable[h] = current; /* update hash table */
if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
if ( (matchIndex < lowestIndex) ||
(MEM_read32(match) != MEM_read32(ip)) ) {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
{ const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
U32 offset;
mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4;
while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
offset = current - matchIndex;
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} }
/* found a match : store it */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2;
hashTable[ZSTD_hashPtr(ip-2, hBits, mls)] = (U32)(ip-2-base);
/* check immediate repcode */
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex)) /* intentional overflow */
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, lowPrefixPtr) + 4;
U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, repLength2-MINMATCH);
hashTable[ZSTD_hashPtr(ip, hBits, mls)] = current2;
ip += repLength2;
anchor = ip;
continue;
}
break;
} } }
/* save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1; seqStorePtr->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_fast_extDict(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
U32 const mls = ctx->appliedParams.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 7); return;
}
}

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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#ifndef ZSTD_FAST_H
#define ZSTD_FAST_H
#include "zstd_compress.h"
#if defined (__cplusplus)
extern "C" {
#endif
void ZSTD_fillHashTable(ZSTD_CCtx* zc, const void* end, const U32 mls);
void ZSTD_compressBlock_fast(ZSTD_CCtx* ctx,
const void* src, size_t srcSize);
void ZSTD_compressBlock_fast_extDict(ZSTD_CCtx* ctx,
const void* src, size_t srcSize);
#if defined (__cplusplus)
}
#endif
#endif /* ZSTD_FAST_H */

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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#include "zstd_lazy.h"
/*-*************************************
* Binary Tree search
***************************************/
/** ZSTD_insertBt1() : add one or multiple positions to tree.
* ip : assumed <= iend-8 .
* @return : nb of positions added */
static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares,
U32 extDict)
{
U32* const hashTable = zc->hashTable;
U32 const hashLog = zc->appliedParams.cParams.hashLog;
size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const bt = zc->chainTable;
U32 const btLog = zc->appliedParams.cParams.chainLog - 1;
U32 const btMask = (1 << btLog) - 1;
U32 matchIndex = hashTable[h];
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* match;
const U32 current = (U32)(ip-base);
const U32 btLow = btMask >= current ? 0 : current - btMask;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = smallerPtr + 1;
U32 dummy32; /* to be nullified at the end */
U32 const windowLow = zc->lowLimit;
U32 matchEndIdx = current+8;
size_t bestLength = 8;
#ifdef ZSTD_C_PREDICT
U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0);
U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1);
predictedSmall += (predictedSmall>0);
predictedLarge += (predictedLarge>0);
#endif /* ZSTD_C_PREDICT */
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
#ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */
const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */
if (matchIndex == predictedSmall) {
/* no need to check length, result known */
*smallerPtr = matchIndex;
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
predictedSmall = predictPtr[1] + (predictPtr[1]>0);
continue;
}
if (matchIndex == predictedLarge) {
*largerPtr = matchIndex;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
predictedLarge = predictPtr[0] + (predictPtr[0]>0);
continue;
}
#endif
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength])
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
bestLength = matchLength;
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
}
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
if (match[matchLength] < ip[matchLength]) { /* necessarily within correct buffer */
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */
if (matchEndIdx > current + 8) return matchEndIdx - current - 8;
return 1;
}
static size_t ZSTD_insertBtAndFindBestMatch (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iend,
size_t* offsetPtr,
U32 nbCompares, const U32 mls,
U32 extDict)
{
U32* const hashTable = zc->hashTable;
U32 const hashLog = zc->appliedParams.cParams.hashLog;
size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const bt = zc->chainTable;
U32 const btLog = zc->appliedParams.cParams.chainLog - 1;
U32 const btMask = (1 << btLog) - 1;
U32 matchIndex = hashTable[h];
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const U32 current = (U32)(ip-base);
const U32 btLow = btMask >= current ? 0 : current - btMask;
const U32 windowLow = zc->lowLimit;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 matchEndIdx = current+8;
U32 dummy32; /* to be nullified at the end */
size_t bestLength = 0;
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength])
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop, to guarantee consistency (miss a little bit of compression) */
}
if (match[matchLength] < ip[matchLength]) {
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
return bestLength;
}
void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while(idx < target)
idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 0);
}
/** ZSTD_BtFindBestMatch() : Tree updater, providing best match */
static size_t ZSTD_BtFindBestMatch (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 0);
}
static size_t ZSTD_BtFindBestMatch_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
case 5 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
case 7 :
case 6 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
}
}
void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while (idx < target) idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 1);
}
/** Tree updater, providing best match */
static size_t ZSTD_BtFindBestMatch_extDict (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 1);
}
static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
case 5 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
case 7 :
case 6 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
}
}
/* *********************************
* Hash Chain
***********************************/
#define NEXT_IN_CHAIN(d, mask) chainTable[(d) & mask]
/* Update chains up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
U32 ZSTD_insertAndFindFirstIndex (ZSTD_CCtx* zc, const BYTE* ip, U32 mls)
{
U32* const hashTable = zc->hashTable;
const U32 hashLog = zc->appliedParams.cParams.hashLog;
U32* const chainTable = zc->chainTable;
const U32 chainMask = (1 << zc->appliedParams.cParams.chainLog) - 1;
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while(idx < target) { /* catch up */
size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls);
NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
hashTable[h] = idx;
idx++;
}
zc->nextToUpdate = target;
return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
}
/* inlining is important to hardwire a hot branch (template emulation) */
FORCE_INLINE_TEMPLATE
size_t ZSTD_HcFindBestMatch_generic (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls, const U32 extDict)
{
U32* const chainTable = zc->chainTable;
const U32 chainSize = (1 << zc->appliedParams.cParams.chainLog);
const U32 chainMask = chainSize-1;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const U32 lowLimit = zc->lowLimit;
const U32 current = (U32)(ip-base);
const U32 minChain = current > chainSize ? current - chainSize : 0;
int nbAttempts=maxNbAttempts;
size_t ml=4-1;
/* HC4 match finder */
U32 matchIndex = ZSTD_insertAndFindFirstIndex (zc, ip, mls);
for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
const BYTE* match;
size_t currentMl=0;
if ((!extDict) || matchIndex >= dictLimit) {
match = base + matchIndex;
if (match[ml] == ip[ml]) /* potentially better */
currentMl = ZSTD_count(ip, match, iLimit);
} else {
match = dictBase + matchIndex;
if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */
currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dictEnd, prefixStart) + 4;
}
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
*offsetPtr = current - matchIndex + ZSTD_REP_MOVE;
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
if (matchIndex <= minChain) break;
matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
}
return ml;
}
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
ZSTD_CCtx* zc,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 0);
case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 0);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 0);
}
}
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
ZSTD_CCtx* zc,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 1);
case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 1);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 1);
}
}
/* *******************************
* Common parser - lazy strategy
*********************************/
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 searchMethod, const U32 depth)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base + ctx->dictLimit;
U32 const maxSearches = 1 << ctx->appliedParams.cParams.searchLog;
U32 const mls = ctx->appliedParams.cParams.searchLength;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
U32 maxNbAttempts, U32 matchLengthSearch);
searchMax_f const searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
U32 offset_1 = seqStorePtr->rep[0], offset_2 = seqStorePtr->rep[1], savedOffset=0;
/* init */
ip += (ip==base);
ctx->nextToUpdate3 = ctx->nextToUpdate;
{ U32 const maxRep = (U32)(ip-base);
if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
}
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
/* check repCode */
if ((offset_1>0) & (MEM_read32(ip+1) == MEM_read32(ip+1 - offset_1))) {
/* repcode : we take it */
matchLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
if (depth==0) goto _storeSequence;
}
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound;
}
if (matchLength < 4) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* let's try to find a better solution */
if (depth>=1)
while (ip<ilimit) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(mlRep * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
if ((ml2 >= 4) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */
} }
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const ml2 = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(ml2 * 4);
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((ml2 >= 4) && (gain2 > gain1))
matchLength = ml2, offset = 0, start = ip;
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
if ((ml2 >= 4) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* NOTE:
* start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
* (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
* overflows the pointer, which is undefined behavior.
*/
/* catch up */
if (offset) {
while ( (start > anchor)
&& (start > base+offset-ZSTD_REP_MOVE)
&& (start[-1] == (start-offset+ZSTD_REP_MOVE)[-1]) ) /* only search for offset within prefix */
{ start--; matchLength++; }
offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
}
/* store sequence */
_storeSequence:
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, (U32)offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while ( (ip <= ilimit)
&& ((offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
} }
/* Save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1 ? offset_1 : savedOffset;
seqStorePtr->repToConfirm[1] = offset_2 ? offset_2 : savedOffset;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_btlazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 1, 2);
}
void ZSTD_compressBlock_lazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 2);
}
void ZSTD_compressBlock_lazy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 1);
}
void ZSTD_compressBlock_greedy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 0);
}
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 searchMethod, const U32 depth)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const U32 dictLimit = ctx->dictLimit;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const dictStart = dictBase + ctx->lowLimit;
const U32 maxSearches = 1 << ctx->appliedParams.cParams.searchLog;
const U32 mls = ctx->appliedParams.cParams.searchLength;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
U32 maxNbAttempts, U32 matchLengthSearch);
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS_extDict : ZSTD_HcFindBestMatch_extDict_selectMLS;
U32 offset_1 = seqStorePtr->rep[0], offset_2 = seqStorePtr->rep[1];
/* init */
ctx->nextToUpdate3 = ctx->nextToUpdate;
ip += (ip == prefixStart);
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
U32 current = (U32)(ip-base);
/* check repCode */
{ const U32 repIndex = (U32)(current+1 - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repEnd, prefixStart) + 4;
if (depth==0) goto _storeSequence;
} }
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound;
}
if (matchLength < 4) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* let's try to find a better solution */
if (depth>=1)
while (ip<ilimit) {
ip ++;
current++;
/* check repCode */
if (offset) {
const U32 repIndex = (U32)(current - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
int const gain2 = (int)(repLength * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((repLength >= 4) && (gain2 > gain1))
matchLength = repLength, offset = 0, start = ip;
} }
/* search match, depth 1 */
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
if ((ml2 >= 4) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */
} }
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
current++;
/* check repCode */
if (offset) {
const U32 repIndex = (U32)(current - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
int const gain2 = (int)(repLength * 4);
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((repLength >= 4) && (gain2 > gain1))
matchLength = repLength, offset = 0, start = ip;
} }
/* search match, depth 2 */
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
if ((ml2 >= 4) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* catch up */
if (offset) {
U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
}
/* store sequence */
_storeSequence:
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, (U32)offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while (ip <= ilimit) {
const U32 repIndex = (U32)((ip-base) - offset_2);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset history */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
}
break;
} }
/* Save reps for next block */
seqStorePtr->repToConfirm[0] = offset_1; seqStorePtr->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 0);
}
void ZSTD_compressBlock_lazy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 1);
}
void ZSTD_compressBlock_lazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 2);
}
void ZSTD_compressBlock_btlazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 1, 2);
}

37
lib/compress/zstd_lazy.h Normal file
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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#ifndef ZSTD_LAZY_H
#define ZSTD_LAZY_H
#include "zstd_compress.h"
#if defined (__cplusplus)
extern "C" {
#endif
U32 ZSTD_insertAndFindFirstIndex (ZSTD_CCtx* zc, const BYTE* ip, U32 mls);
void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls);
void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls);
void ZSTD_compressBlock_btlazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_lazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_lazy(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_greedy(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_lazy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_lazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_btlazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
#if defined (__cplusplus)
}
#endif
#endif /* ZSTD_LAZY_H */

954
lib/compress/zstd_opt.c Normal file
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/*
* Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#include "zstd_opt.h"
#include "zstd_lazy.h"
#define ZSTD_LITFREQ_ADD 2
#define ZSTD_FREQ_DIV 4
#define ZSTD_MAX_PRICE (1<<30)
/*-*************************************
* Price functions for optimal parser
***************************************/
static void ZSTD_setLog2Prices(optState_t* optPtr)
{
optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1);
optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1);
optPtr->factor = 1 + ((optPtr->litSum>>5) / optPtr->litLengthSum) + ((optPtr->litSum<<1) / (optPtr->litSum + optPtr->matchSum));
}
static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSize)
{
unsigned u;
optPtr->cachedLiterals = NULL;
optPtr->cachedPrice = optPtr->cachedLitLength = 0;
optPtr->staticPrices = 0;
if (optPtr->litLengthSum == 0) {
if (srcSize <= 1024) optPtr->staticPrices = 1;
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;
optPtr->litLengthSum = MaxLL+1;
optPtr->matchLengthSum = MaxML+1;
optPtr->offCodeSum = (MaxOff+1);
optPtr->matchSum = (ZSTD_LITFREQ_ADD<<Litbits);
for (u=0; u<=MaxLit; u++) {
optPtr->litFreq[u] = 1 + (optPtr->litFreq[u]>>ZSTD_FREQ_DIV);
optPtr->litSum += optPtr->litFreq[u];
}
for (u=0; u<=MaxLL; u++)
optPtr->litLengthFreq[u] = 1;
for (u=0; u<=MaxML; u++)
optPtr->matchLengthFreq[u] = 1;
for (u=0; u<=MaxOff; u++)
optPtr->offCodeFreq[u] = 1;
} else {
optPtr->matchLengthSum = 0;
optPtr->litLengthSum = 0;
optPtr->offCodeSum = 0;
optPtr->matchSum = 0;
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];
}
for (u=0; u<=MaxLL; u++) {
optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1));
optPtr->litLengthSum += optPtr->litLengthFreq[u];
}
for (u=0; u<=MaxML; u++) {
optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
optPtr->matchSum += optPtr->matchLengthFreq[u] * (u + 3);
}
optPtr->matchSum *= ZSTD_LITFREQ_ADD;
for (u=0; u<=MaxOff; u++) {
optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
optPtr->offCodeSum += optPtr->offCodeFreq[u];
}
}
ZSTD_setLog2Prices(optPtr);
}
static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* literals)
{
U32 price, u;
if (optPtr->staticPrices)
return ZSTD_highbit32((U32)litLength+1) + (litLength*6);
if (litLength == 0)
return optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[0]+1);
/* literals */
if (optPtr->cachedLiterals == literals) {
U32 const additional = litLength - optPtr->cachedLitLength;
const BYTE* literals2 = optPtr->cachedLiterals + optPtr->cachedLitLength;
price = optPtr->cachedPrice + additional * optPtr->log2litSum;
for (u=0; u < additional; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals2[u]]+1);
optPtr->cachedPrice = price;
optPtr->cachedLitLength = litLength;
} else {
price = litLength * optPtr->log2litSum;
for (u=0; u < litLength; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
if (litLength >= 12) {
optPtr->cachedLiterals = literals;
optPtr->cachedPrice = price;
optPtr->cachedLitLength = litLength;
}
}
/* literal Length */
{ const BYTE LL_deltaCode = 19;
const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
price += LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
}
return price;
}
FORCE_INLINE_TEMPLATE U32 ZSTD_getPrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength, const int ultra)
{
/* offset */
U32 price;
BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
if (optPtr->staticPrices)
return ZSTD_getLiteralPrice(optPtr, litLength, literals) + ZSTD_highbit32((U32)matchLength+1) + 16 + offCode;
price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
if (!ultra && offCode >= 20) price += (offCode-19)*2;
/* match Length */
{ const BYTE ML_deltaCode = 36;
const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
}
return price + ZSTD_getLiteralPrice(optPtr, litLength, literals) + optPtr->factor;
}
static void ZSTD_updatePrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength)
{
U32 u;
/* literals */
optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
for (u=0; u < litLength; u++)
optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
/* literal Length */
{ const BYTE LL_deltaCode = 19;
const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
optPtr->litLengthFreq[llCode]++;
optPtr->litLengthSum++;
}
/* match offset */
{ BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
optPtr->offCodeSum++;
optPtr->offCodeFreq[offCode]++;
}
/* match Length */
{ const BYTE ML_deltaCode = 36;
const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
optPtr->matchLengthFreq[mlCode]++;
optPtr->matchLengthSum++;
}
ZSTD_setLog2Prices(optPtr);
}
#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \
{ \
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
opt[pos].mlen = mlen_; \
opt[pos].off = offset_; \
opt[pos].litlen = litlen_; \
opt[pos].price = price_; \
}
/* function safe only for comparisons */
static U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
{
switch (length)
{
default :
case 4 : return MEM_read32(memPtr);
case 3 : if (MEM_isLittleEndian())
return MEM_read32(memPtr)<<8;
else
return MEM_read32(memPtr)>>8;
}
}
/* Update hashTable3 up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
static
U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
{
U32* const hashTable3 = zc->hashTable3;
U32 const hashLog3 = zc->hashLog3;
const BYTE* const base = zc->base;
U32 idx = zc->nextToUpdate3;
const U32 target = zc->nextToUpdate3 = (U32)(ip - base);
const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3);
while(idx < target) {
hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
idx++;
}
return hashTable3[hash3];
}
/*-*************************************
* Binary Tree search
***************************************/
static U32 ZSTD_insertBtAndGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
U32 nbCompares, const U32 mls,
U32 extDict, ZSTD_match_t* matches, const U32 minMatchLen)
{
const BYTE* const base = zc->base;
const U32 current = (U32)(ip-base);
const U32 hashLog = zc->appliedParams.cParams.hashLog;
const size_t h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const hashTable = zc->hashTable;
U32 matchIndex = hashTable[h];
U32* const bt = zc->chainTable;
const U32 btLog = zc->appliedParams.cParams.chainLog - 1;
const U32 btMask= (1U << btLog) - 1;
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const U32 btLow = btMask >= current ? 0 : current - btMask;
const U32 windowLow = zc->lowLimit;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 matchEndIdx = current+8;
U32 dummy32; /* to be nullified at the end */
U32 mnum = 0;
const U32 minMatch = (mls == 3) ? 3 : 4;
size_t bestLength = minMatchLen-1;
if (minMatch == 3) { /* HC3 match finder */
U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3 (zc, ip);
if (matchIndex3>windowLow && (current - matchIndex3 < (1<<18))) {
const BYTE* match;
size_t currentMl=0;
if ((!extDict) || matchIndex3 >= dictLimit) {
match = base + matchIndex3;
if (match[bestLength] == ip[bestLength]) currentMl = ZSTD_count(ip, match, iLimit);
} else {
match = dictBase + matchIndex3;
if (ZSTD_readMINMATCH(match, MINMATCH) == ZSTD_readMINMATCH(ip, MINMATCH)) /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */
currentMl = ZSTD_count_2segments(ip+MINMATCH, match+MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH;
}
/* save best solution */
if (currentMl > bestLength) {
bestLength = currentMl;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex3;
matches[mnum].len = (U32)currentMl;
mnum++;
if (currentMl > ZSTD_OPT_NUM) goto update;
if (ip+currentMl == iLimit) goto update; /* best possible, and avoid read overflow*/
}
}
}
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength]) {
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iLimit) +1;
}
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
if (matchLength > matchEndIdx - matchIndex) matchEndIdx = matchIndex + (U32)matchLength;
bestLength = matchLength;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex;
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 guarantee consistency (miss a little bit of compression) */
}
if (match[matchLength] < ip[matchLength]) {
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
update:
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
return mnum;
}
/** Tree updater, providing best match */
static U32 ZSTD_BtGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
}
}
/** Tree updater, providing best match */
static U32 ZSTD_BtGetAllMatches_extDict (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
}
}
/*-*******************************
* Optimal parser
*********************************/
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize, const int ultra)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
optState_t* optStatePtr = &(ctx->optState);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const BYTE* const prefixStart = base + ctx->dictLimit;
const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
const U32 sufficient_len = ctx->appliedParams.cParams.targetLength;
const U32 mls = ctx->appliedParams.cParams.searchLength;
const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
ZSTD_optimal_t* opt = optStatePtr->priceTable;
ZSTD_match_t* matches = optStatePtr->matchTable;
const BYTE* inr;
U32 offset, rep[ZSTD_REP_NUM];
/* init */
ctx->nextToUpdate3 = ctx->nextToUpdate;
ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
ip += (ip==prefixStart);
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; }
/* Match Loop */
while (ip < ilimit) {
U32 cur, match_num, last_pos, litlen, price;
U32 u, mlen, best_mlen, best_off, litLength;
memset(opt, 0, sizeof(ZSTD_optimal_t));
last_pos = 0;
litlen = (U32)(ip - anchor);
/* check repCode */
{ U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
for (i=(ip == anchor); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
if ( (repCur > 0) && (repCur < (S32)(ip-prefixStart))
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) {
mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repCur, iend) + minMatch;
if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
best_off = i - (ip == anchor);
do {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch);
if (!last_pos && !match_num) { ip++; continue; }
if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
cur = 0;
last_pos = 1;
goto _storeSequence;
}
/* set prices using matches at position = 0 */
best_mlen = (last_pos) ? last_pos : minMatch;
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */
mlen++;
} }
if (last_pos < minMatch) { 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].litlen = litlen;
/* check further positions */
for (cur = 1; cur <= last_pos; cur++) {
inr = ip + cur;
if (opt[cur-1].mlen == 1) {
litlen = opt[cur-1].litlen + 1;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen);
} else
price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor);
} else {
litlen = 1;
price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1);
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
if (cur == last_pos) break;
if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
continue;
mlen = opt[cur].mlen;
if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
opt[cur].rep[2] = opt[cur-mlen].rep[1];
opt[cur].rep[1] = opt[cur-mlen].rep[0];
opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;
{ U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
for (i=(opt[cur].mlen != 1); i<last_i; i++) { /* check rep */
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
if ( (repCur > 0) && (repCur < (S32)(inr-prefixStart))
&& (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) {
mlen = (U32)ZSTD_count(inr+minMatch, inr+minMatch - repCur, iend) + minMatch;
if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; last_pos = cur + 1;
goto _storeSequence;
}
best_off = i - (opt[cur].mlen != 1);
if (mlen > best_mlen) best_mlen = mlen;
do {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
} else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen);
if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
last_pos = cur + 1;
goto _storeSequence;
}
/* set prices using matches at position = cur */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen)
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
mlen++;
} } }
best_mlen = opt[last_pos].mlen;
best_off = opt[last_pos].off;
cur = last_pos - best_mlen;
/* store sequence */
_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
opt[0].mlen = 1;
while (1) {
mlen = opt[cur].mlen;
offset = opt[cur].off;
opt[cur].mlen = best_mlen;
opt[cur].off = best_off;
best_mlen = mlen;
best_off = offset;
if (mlen > cur) break;
cur -= mlen;
}
for (u = 0; u <= last_pos;) {
u += opt[u].mlen;
}
for (cur=0; cur < last_pos; ) {
mlen = opt[cur].mlen;
if (mlen == 1) { ip++; cur++; continue; }
offset = opt[cur].off;
cur += mlen;
litLength = (U32)(ip - anchor);
if (offset > ZSTD_REP_MOVE_OPT) {
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - ZSTD_REP_MOVE_OPT;
offset--;
} else {
if (offset != 0) {
best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
if (offset != 1) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength==0) offset--;
}
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
anchor = ip = ip + mlen;
} } /* for (cur=0; cur < last_pos; ) */
/* Save reps for next block */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; }
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0);
}
void ZSTD_compressBlock_btultra(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 1);
}
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize, const int ultra)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
optState_t* optStatePtr = &(ctx->optState);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const U32 lowestIndex = ctx->lowLimit;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const dictEnd = dictBase + dictLimit;
const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
const U32 sufficient_len = ctx->appliedParams.cParams.targetLength;
const U32 mls = ctx->appliedParams.cParams.searchLength;
const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
ZSTD_optimal_t* opt = optStatePtr->priceTable;
ZSTD_match_t* matches = optStatePtr->matchTable;
const BYTE* inr;
/* init */
U32 offset, rep[ZSTD_REP_NUM];
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; }
ctx->nextToUpdate3 = ctx->nextToUpdate;
ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
ip += (ip==prefixStart);
/* Match Loop */
while (ip < ilimit) {
U32 cur, match_num, last_pos, litlen, price;
U32 u, mlen, best_mlen, best_off, litLength;
U32 current = (U32)(ip-base);
memset(opt, 0, sizeof(ZSTD_optimal_t));
last_pos = 0;
opt[0].litlen = (U32)(ip - anchor);
/* check repCode */
{ U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
for (i = (ip==anchor); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
const U32 repIndex = (U32)(current - repCur);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( (repCur > 0 && repCur <= (S32)current)
&& (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
mlen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
best_off = i - (ip==anchor);
litlen = opt[0].litlen;
do {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */
if (!last_pos && !match_num) { ip++; continue; }
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; }
opt[0].mlen = 1;
if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
cur = 0;
last_pos = 1;
goto _storeSequence;
}
best_mlen = (last_pos) ? last_pos : minMatch;
/* set prices using matches at position = 0 */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
litlen = opt[0].litlen;
while (mlen <= best_mlen) {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, matches[u].off, litlen, price);
mlen++;
} }
if (last_pos < minMatch) {
ip++; continue;
}
/* check further positions */
for (cur = 1; cur <= last_pos; cur++) {
inr = ip + cur;
if (opt[cur-1].mlen == 1) {
litlen = opt[cur-1].litlen + 1;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen);
} else
price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor);
} else {
litlen = 1;
price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1);
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
if (cur == last_pos) break;
if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
continue;
mlen = opt[cur].mlen;
if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
opt[cur].rep[2] = opt[cur-mlen].rep[1];
opt[cur].rep[1] = opt[cur-mlen].rep[0];
opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;
{ U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
for (i = (mlen != 1); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
const U32 repIndex = (U32)(current+cur - repCur);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( (repCur > 0 && repCur <= (S32)(current+cur))
&& (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */
&& (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
mlen = (U32)ZSTD_count_2segments(inr+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; last_pos = cur + 1;
goto _storeSequence;
}
best_off = i - (opt[cur].mlen != 1);
if (mlen > best_mlen) best_mlen = mlen;
do {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
} else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch);
if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
last_pos = cur + 1;
goto _storeSequence;
}
/* set prices using matches at position = cur */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen)
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
mlen++;
} } } /* for (cur = 1; cur <= last_pos; cur++) */
best_mlen = opt[last_pos].mlen;
best_off = opt[last_pos].off;
cur = last_pos - best_mlen;
/* store sequence */
_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
opt[0].mlen = 1;
while (1) {
mlen = opt[cur].mlen;
offset = opt[cur].off;
opt[cur].mlen = best_mlen;
opt[cur].off = best_off;
best_mlen = mlen;
best_off = offset;
if (mlen > cur) break;
cur -= mlen;
}
for (u = 0; u <= last_pos; ) {
u += opt[u].mlen;
}
for (cur=0; cur < last_pos; ) {
mlen = opt[cur].mlen;
if (mlen == 1) { ip++; cur++; continue; }
offset = opt[cur].off;
cur += mlen;
litLength = (U32)(ip - anchor);
if (offset > ZSTD_REP_MOVE_OPT) {
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - ZSTD_REP_MOVE_OPT;
offset--;
} else {
if (offset != 0) {
best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
if (offset != 1) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength==0) offset--;
}
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
anchor = ip = ip + mlen;
} } /* for (cur=0; cur < last_pos; ) */
/* Save reps for next block */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; }
/* Last Literals */
{ size_t lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_btopt_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 0);
}
void ZSTD_compressBlock_btultra_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 1);
}

937
lib/compress/zstd_opt.h
View File

@@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc. * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved. * All rights reserved.
* *
* This source code is licensed under both the BSD-style license (found in the * This source code is licensed under both the BSD-style license (found in the
@@ -7,932 +7,23 @@
* in the COPYING file in the root directory of this source tree). * in the COPYING file in the root directory of this source tree).
*/ */
#ifndef ZSTD_OPT_H
#define ZSTD_OPT_H
/* Note : this file is intended to be included within zstd_compress.c */ #include "zstd_compress.h"
#if defined (__cplusplus)
extern "C" {
#endif
#ifndef ZSTD_OPT_H_91842398743 void ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
#define ZSTD_OPT_H_91842398743 void ZSTD_compressBlock_btultra(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_btopt_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
void ZSTD_compressBlock_btultra_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
#define ZSTD_LITFREQ_ADD 2 #if defined (__cplusplus)
#define ZSTD_FREQ_DIV 4
#define ZSTD_MAX_PRICE (1<<30)
/*-*************************************
* Price functions for optimal parser
***************************************/
static void ZSTD_setLog2Prices(optState_t* optPtr)
{
optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1);
optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1);
optPtr->factor = 1 + ((optPtr->litSum>>5) / optPtr->litLengthSum) + ((optPtr->litSum<<1) / (optPtr->litSum + optPtr->matchSum));
} }
#endif
#endif /* ZSTD_OPT_H */
static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSize)
{
unsigned u;
optPtr->cachedLiterals = NULL;
optPtr->cachedPrice = optPtr->cachedLitLength = 0;
optPtr->staticPrices = 0;
if (optPtr->litLengthSum == 0) {
if (srcSize <= 1024) optPtr->staticPrices = 1;
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;
optPtr->litLengthSum = MaxLL+1;
optPtr->matchLengthSum = MaxML+1;
optPtr->offCodeSum = (MaxOff+1);
optPtr->matchSum = (ZSTD_LITFREQ_ADD<<Litbits);
for (u=0; u<=MaxLit; u++) {
optPtr->litFreq[u] = 1 + (optPtr->litFreq[u]>>ZSTD_FREQ_DIV);
optPtr->litSum += optPtr->litFreq[u];
}
for (u=0; u<=MaxLL; u++)
optPtr->litLengthFreq[u] = 1;
for (u=0; u<=MaxML; u++)
optPtr->matchLengthFreq[u] = 1;
for (u=0; u<=MaxOff; u++)
optPtr->offCodeFreq[u] = 1;
} else {
optPtr->matchLengthSum = 0;
optPtr->litLengthSum = 0;
optPtr->offCodeSum = 0;
optPtr->matchSum = 0;
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];
}
for (u=0; u<=MaxLL; u++) {
optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1));
optPtr->litLengthSum += optPtr->litLengthFreq[u];
}
for (u=0; u<=MaxML; u++) {
optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
optPtr->matchSum += optPtr->matchLengthFreq[u] * (u + 3);
}
optPtr->matchSum *= ZSTD_LITFREQ_ADD;
for (u=0; u<=MaxOff; u++) {
optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
optPtr->offCodeSum += optPtr->offCodeFreq[u];
}
}
ZSTD_setLog2Prices(optPtr);
}
static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* literals)
{
U32 price, u;
if (optPtr->staticPrices)
return ZSTD_highbit32((U32)litLength+1) + (litLength*6);
if (litLength == 0)
return optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[0]+1);
/* literals */
if (optPtr->cachedLiterals == literals) {
U32 const additional = litLength - optPtr->cachedLitLength;
const BYTE* literals2 = optPtr->cachedLiterals + optPtr->cachedLitLength;
price = optPtr->cachedPrice + additional * optPtr->log2litSum;
for (u=0; u < additional; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals2[u]]+1);
optPtr->cachedPrice = price;
optPtr->cachedLitLength = litLength;
} else {
price = litLength * optPtr->log2litSum;
for (u=0; u < litLength; u++)
price -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
if (litLength >= 12) {
optPtr->cachedLiterals = literals;
optPtr->cachedPrice = price;
optPtr->cachedLitLength = litLength;
}
}
/* literal Length */
{ const BYTE LL_deltaCode = 19;
const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
price += LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
}
return price;
}
FORCE_INLINE_TEMPLATE U32 ZSTD_getPrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength, const int ultra)
{
/* offset */
U32 price;
BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
if (optPtr->staticPrices)
return ZSTD_getLiteralPrice(optPtr, litLength, literals) + ZSTD_highbit32((U32)matchLength+1) + 16 + offCode;
price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
if (!ultra && offCode >= 20) price += (offCode-19)*2;
/* match Length */
{ const BYTE ML_deltaCode = 36;
const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
}
return price + ZSTD_getLiteralPrice(optPtr, litLength, literals) + optPtr->factor;
}
static void ZSTD_updatePrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength)
{
U32 u;
/* literals */
optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
for (u=0; u < litLength; u++)
optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
/* literal Length */
{ const BYTE LL_deltaCode = 19;
const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
optPtr->litLengthFreq[llCode]++;
optPtr->litLengthSum++;
}
/* match offset */
{ BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
optPtr->offCodeSum++;
optPtr->offCodeFreq[offCode]++;
}
/* match Length */
{ const BYTE ML_deltaCode = 36;
const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
optPtr->matchLengthFreq[mlCode]++;
optPtr->matchLengthSum++;
}
ZSTD_setLog2Prices(optPtr);
}
#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \
{ \
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
opt[pos].mlen = mlen_; \
opt[pos].off = offset_; \
opt[pos].litlen = litlen_; \
opt[pos].price = price_; \
}
/* function safe only for comparisons */
static U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
{
switch (length)
{
default :
case 4 : return MEM_read32(memPtr);
case 3 : if (MEM_isLittleEndian())
return MEM_read32(memPtr)<<8;
else
return MEM_read32(memPtr)>>8;
}
}
/* Update hashTable3 up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
static
U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
{
U32* const hashTable3 = zc->hashTable3;
U32 const hashLog3 = zc->hashLog3;
const BYTE* const base = zc->base;
U32 idx = zc->nextToUpdate3;
const U32 target = zc->nextToUpdate3 = (U32)(ip - base);
const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3);
while(idx < target) {
hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
idx++;
}
return hashTable3[hash3];
}
/*-*************************************
* Binary Tree search
***************************************/
static U32 ZSTD_insertBtAndGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
U32 nbCompares, const U32 mls,
U32 extDict, ZSTD_match_t* matches, const U32 minMatchLen)
{
const BYTE* const base = zc->base;
const U32 current = (U32)(ip-base);
const U32 hashLog = zc->appliedParams.cParams.hashLog;
const size_t h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const hashTable = zc->hashTable;
U32 matchIndex = hashTable[h];
U32* const bt = zc->chainTable;
const U32 btLog = zc->appliedParams.cParams.chainLog - 1;
const U32 btMask= (1U << btLog) - 1;
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const U32 btLow = btMask >= current ? 0 : current - btMask;
const U32 windowLow = zc->lowLimit;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 matchEndIdx = current+8;
U32 dummy32; /* to be nullified at the end */
U32 mnum = 0;
const U32 minMatch = (mls == 3) ? 3 : 4;
size_t bestLength = minMatchLen-1;
if (minMatch == 3) { /* HC3 match finder */
U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3 (zc, ip);
if (matchIndex3>windowLow && (current - matchIndex3 < (1<<18))) {
const BYTE* match;
size_t currentMl=0;
if ((!extDict) || matchIndex3 >= dictLimit) {
match = base + matchIndex3;
if (match[bestLength] == ip[bestLength]) currentMl = ZSTD_count(ip, match, iLimit);
} else {
match = dictBase + matchIndex3;
if (ZSTD_readMINMATCH(match, MINMATCH) == ZSTD_readMINMATCH(ip, MINMATCH)) /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */
currentMl = ZSTD_count_2segments(ip+MINMATCH, match+MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH;
}
/* save best solution */
if (currentMl > bestLength) {
bestLength = currentMl;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex3;
matches[mnum].len = (U32)currentMl;
mnum++;
if (currentMl > ZSTD_OPT_NUM) goto update;
if (ip+currentMl == iLimit) goto update; /* best possible, and avoid read overflow*/
}
}
}
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength]) {
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iLimit) +1;
}
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
if (matchLength > matchEndIdx - matchIndex) matchEndIdx = matchIndex + (U32)matchLength;
bestLength = matchLength;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex;
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 guarantee consistency (miss a little bit of compression) */
}
if (match[matchLength] < ip[matchLength]) {
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
update:
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
return mnum;
}
/** Tree updater, providing best match */
static U32 ZSTD_BtGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
}
}
/** Tree updater, providing best match */
static U32 ZSTD_BtGetAllMatches_extDict (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
}
}
/*-*******************************
* Optimal parser
*********************************/
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize, const int ultra)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
optState_t* optStatePtr = &(ctx->optState);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const BYTE* const prefixStart = base + ctx->dictLimit;
const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
const U32 sufficient_len = ctx->appliedParams.cParams.targetLength;
const U32 mls = ctx->appliedParams.cParams.searchLength;
const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
ZSTD_optimal_t* opt = optStatePtr->priceTable;
ZSTD_match_t* matches = optStatePtr->matchTable;
const BYTE* inr;
U32 offset, rep[ZSTD_REP_NUM];
/* init */
ctx->nextToUpdate3 = ctx->nextToUpdate;
ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
ip += (ip==prefixStart);
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; }
/* Match Loop */
while (ip < ilimit) {
U32 cur, match_num, last_pos, litlen, price;
U32 u, mlen, best_mlen, best_off, litLength;
memset(opt, 0, sizeof(ZSTD_optimal_t));
last_pos = 0;
litlen = (U32)(ip - anchor);
/* check repCode */
{ U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
for (i=(ip == anchor); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
if ( (repCur > 0) && (repCur < (S32)(ip-prefixStart))
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) {
mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repCur, iend) + minMatch;
if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
best_off = i - (ip == anchor);
do {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch);
if (!last_pos && !match_num) { ip++; continue; }
if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
cur = 0;
last_pos = 1;
goto _storeSequence;
}
/* set prices using matches at position = 0 */
best_mlen = (last_pos) ? last_pos : minMatch;
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */
mlen++;
} }
if (last_pos < minMatch) { 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].litlen = litlen;
/* check further positions */
for (cur = 1; cur <= last_pos; cur++) {
inr = ip + cur;
if (opt[cur-1].mlen == 1) {
litlen = opt[cur-1].litlen + 1;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen);
} else
price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor);
} else {
litlen = 1;
price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1);
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
if (cur == last_pos) break;
if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
continue;
mlen = opt[cur].mlen;
if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
opt[cur].rep[2] = opt[cur-mlen].rep[1];
opt[cur].rep[1] = opt[cur-mlen].rep[0];
opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;
{ U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
for (i=(opt[cur].mlen != 1); i<last_i; i++) { /* check rep */
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
if ( (repCur > 0) && (repCur < (S32)(inr-prefixStart))
&& (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) {
mlen = (U32)ZSTD_count(inr+minMatch, inr+minMatch - repCur, iend) + minMatch;
if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; last_pos = cur + 1;
goto _storeSequence;
}
best_off = i - (opt[cur].mlen != 1);
if (mlen > best_mlen) best_mlen = mlen;
do {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
} else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen);
if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
last_pos = cur + 1;
goto _storeSequence;
}
/* set prices using matches at position = cur */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen)
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
mlen++;
} } }
best_mlen = opt[last_pos].mlen;
best_off = opt[last_pos].off;
cur = last_pos - best_mlen;
/* store sequence */
_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
opt[0].mlen = 1;
while (1) {
mlen = opt[cur].mlen;
offset = opt[cur].off;
opt[cur].mlen = best_mlen;
opt[cur].off = best_off;
best_mlen = mlen;
best_off = offset;
if (mlen > cur) break;
cur -= mlen;
}
for (u = 0; u <= last_pos;) {
u += opt[u].mlen;
}
for (cur=0; cur < last_pos; ) {
mlen = opt[cur].mlen;
if (mlen == 1) { ip++; cur++; continue; }
offset = opt[cur].off;
cur += mlen;
litLength = (U32)(ip - anchor);
if (offset > ZSTD_REP_MOVE_OPT) {
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - ZSTD_REP_MOVE_OPT;
offset--;
} else {
if (offset != 0) {
best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
if (offset != 1) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength==0) offset--;
}
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
anchor = ip = ip + mlen;
} } /* for (cur=0; cur < last_pos; ) */
/* Save reps for next block */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; }
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
FORCE_INLINE_TEMPLATE
void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize, const int ultra)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
optState_t* optStatePtr = &(ctx->optState);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const U32 lowestIndex = ctx->lowLimit;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const dictEnd = dictBase + dictLimit;
const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog;
const U32 sufficient_len = ctx->appliedParams.cParams.targetLength;
const U32 mls = ctx->appliedParams.cParams.searchLength;
const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4;
ZSTD_optimal_t* opt = optStatePtr->priceTable;
ZSTD_match_t* matches = optStatePtr->matchTable;
const BYTE* inr;
/* init */
U32 offset, rep[ZSTD_REP_NUM];
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; }
ctx->nextToUpdate3 = ctx->nextToUpdate;
ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
ip += (ip==prefixStart);
/* Match Loop */
while (ip < ilimit) {
U32 cur, match_num, last_pos, litlen, price;
U32 u, mlen, best_mlen, best_off, litLength;
U32 current = (U32)(ip-base);
memset(opt, 0, sizeof(ZSTD_optimal_t));
last_pos = 0;
opt[0].litlen = (U32)(ip - anchor);
/* check repCode */
{ U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
for (i = (ip==anchor); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
const U32 repIndex = (U32)(current - repCur);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( (repCur > 0 && repCur <= (S32)current)
&& (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
mlen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
best_off = i - (ip==anchor);
litlen = opt[0].litlen;
do {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */
if (!last_pos && !match_num) { ip++; continue; }
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; }
opt[0].mlen = 1;
if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
cur = 0;
last_pos = 1;
goto _storeSequence;
}
best_mlen = (last_pos) ? last_pos : minMatch;
/* set prices using matches at position = 0 */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
litlen = opt[0].litlen;
while (mlen <= best_mlen) {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, matches[u].off, litlen, price);
mlen++;
} }
if (last_pos < minMatch) {
ip++; continue;
}
/* check further positions */
for (cur = 1; cur <= last_pos; cur++) {
inr = ip + cur;
if (opt[cur-1].mlen == 1) {
litlen = opt[cur-1].litlen + 1;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen);
} else
price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor);
} else {
litlen = 1;
price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1);
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
if (cur == last_pos) break;
if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
continue;
mlen = opt[cur].mlen;
if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
opt[cur].rep[2] = opt[cur-mlen].rep[1];
opt[cur].rep[1] = opt[cur-mlen].rep[0];
opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;
{ U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
for (i = (mlen != 1); i<last_i; i++) {
const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
const U32 repIndex = (U32)(current+cur - repCur);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( (repCur > 0 && repCur <= (S32)(current+cur))
&& (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */
&& (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
mlen = (U32)ZSTD_count_2segments(inr+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
best_mlen = mlen; best_off = i; last_pos = cur + 1;
goto _storeSequence;
}
best_off = i - (opt[cur].mlen != 1);
if (mlen > best_mlen) best_mlen = mlen;
do {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
} else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch);
if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
best_off = matches[match_num-1].off;
last_pos = cur + 1;
goto _storeSequence;
}
/* set prices using matches at position = cur */
for (u = 0; u < match_num; u++) {
mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
best_mlen = matches[u].len;
while (mlen <= best_mlen) {
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen)
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
} else {
litlen = 0;
price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
mlen++;
} } } /* for (cur = 1; cur <= last_pos; cur++) */
best_mlen = opt[last_pos].mlen;
best_off = opt[last_pos].off;
cur = last_pos - best_mlen;
/* store sequence */
_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
opt[0].mlen = 1;
while (1) {
mlen = opt[cur].mlen;
offset = opt[cur].off;
opt[cur].mlen = best_mlen;
opt[cur].off = best_off;
best_mlen = mlen;
best_off = offset;
if (mlen > cur) break;
cur -= mlen;
}
for (u = 0; u <= last_pos; ) {
u += opt[u].mlen;
}
for (cur=0; cur < last_pos; ) {
mlen = opt[cur].mlen;
if (mlen == 1) { ip++; cur++; continue; }
offset = opt[cur].off;
cur += mlen;
litLength = (U32)(ip - anchor);
if (offset > ZSTD_REP_MOVE_OPT) {
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - ZSTD_REP_MOVE_OPT;
offset--;
} else {
if (offset != 0) {
best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
if (offset != 1) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength==0) offset--;
}
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
anchor = ip = ip + mlen;
} } /* for (cur=0; cur < last_pos; ) */
/* Save reps for next block */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; }
/* Last Literals */
{ size_t lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
#endif /* ZSTD_OPT_H_91842398743 */