AuroraMiddleware/zstd
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

introduced ZSTD_compressBlock_greedy

Browse Source
This commit is contained in:
inikep 2016-04-05 19:01:10 +02:00
parent 908fcb384a
commit faa8d8aae1
1 changed files with 196 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

211
lib/zstd_compress.c
View File

@ -1617,6 +1617,194 @@ FORCE_INLINE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
}
/* *******************************
* Common parser - greedy strategy
*********************************/
FORCE_INLINE
void ZSTD_compressBlock_greedy_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
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;
const U32 maxSearches = 1 << ctx->params.cParams.searchLog;
const U32 mls = ctx->params.cParams.searchLength;
/* init */
U32 rep[ZSTD_REP_INIT];
for (U32 i=0; i<ZSTD_REP_INIT; i++)
rep[i]=REPCODE_STARTVALUE;
ZSTD_resetSeqStore(seqStorePtr);
if ((ip-base) < REPCODE_STARTVALUE) ip = base + REPCODE_STARTVALUE;
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
/* check repCode */
if (MEM_read32(start) == MEM_read32(start - rep[0])) {
/* repcode : we take it */
matchLength = ZSTD_count(start+MINMATCH, start+MINMATCH-rep[0], iend) + MINMATCH;
goto _storeSequence;
}
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = ZSTD_HcFindBestMatch_selectMLS(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound + ZSTD_REP_MOVE;
}
if (matchLength < MINMATCH) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* catch up */
while ((start>anchor) && (start>base+offset-ZSTD_REP_MOVE) && (start[-1] == start[-1-offset+ZSTD_REP_MOVE])) /* only search for offset within prefix */
{ start--; matchLength++; }
rep[1] = rep[0]; rep[0] = offset - ZSTD_REP_MOVE;
_storeSequence:
/* store sequence */
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while ( (ip <= ilimit)
&& (MEM_read32(ip) == MEM_read32(ip - rep[1])) ) {
/* store sequence */
matchLength = ZSTD_count(ip+MINMATCH, ip+MINMATCH-rep[1], iend);
offset = rep[1]; rep[1] = rep[0]; rep[0] = offset; /* swap offset history */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength);
ip += matchLength+MINMATCH;
anchor = ip;
continue; /* faster when present ... (?) */
} }
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
ZSTD_statsUpdatePrices(&seqStorePtr->stats, lastLLSize, anchor, 0, 0);
}
}
FORCE_INLINE
void ZSTD_compressBlock_greedy_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
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 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->params.cParams.searchLog;
const U32 mls = ctx->params.cParams.searchLength;
/* init */
U32 rep[ZSTD_REP_INIT];
for (U32 i=0; i<ZSTD_REP_INIT; i++)
rep[i]=REPCODE_STARTVALUE;
ZSTD_resetSeqStore(seqStorePtr);
if ((ip - prefixStart) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
U32 current = (U32)(start-base);
/* check repCode */
{
const U32 repIndex = (U32)(current - rep[0]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow */
if (MEM_read32(start) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(start+MINMATCH, repMatch+MINMATCH, iend, repEnd, prefixStart) + MINMATCH;
goto _storeSequence;
} }
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = ZSTD_HcFindBestMatch_extDict_selectMLS(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound + ZSTD_REP_MOVE;
}
if (matchLength < MINMATCH) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* catch up */
if (offset >= ZSTD_REP_NUM) {
U32 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++; }
rep[1] = rep[0]; rep[0] = offset - ZSTD_REP_MOVE;
}
_storeSequence:
/* store sequence */
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while (ip <= ilimit) {
const U32 repIndex = (U32)((ip-base) - rep[1]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ((U32)((dictLimit-1) - repIndex) >= 3) /* 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+MINMATCH, repMatch+MINMATCH, iend, repEnd, prefixStart) + MINMATCH;
offset = rep[1]; rep[1] = rep[0]; rep[0] = offset; /* swap offset history */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
}
break;
} }
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
/* *******************************
* Common parser - lazy strategy
*********************************/
@ -1635,8 +1823,6 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
const U32 maxSearches = 1 << ctx->params.cParams.searchLog;
const U32 mls = ctx->params.cParams.searchLength;
const U32 repStart = (ctx->params.cParams.strategy == ZSTD_greedy) ? 0 : 0;
const U32 repNum = (ctx->params.cParams.strategy == ZSTD_greedy) ? 2 : ZSTD_REP_NUM;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
@ -1658,13 +1844,12 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
const BYTE* start=ip;
/* check repCode */
for (U32 i=repStart; i<repNum; i++)
for (U32 i=0; i<ZSTD_REP_NUM; i++)
if (MEM_read32(ip) == MEM_read32(ip - rep[i])) {
/* repcode : we take it */
if (matchLength==0) {
matchLength = ZSTD_count(ip+MINMATCH, ip+MINMATCH-rep[i], iend) + MINMATCH;
offset = i;
if (depth==0) goto _storeSequence;
} else {
size_t mlRep = ZSTD_count(ip+MINMATCH, ip+MINMATCH-rep[i], iend) + MINMATCH;
int gain2 = (int)(mlRep * 3 /*- ZSTD_highbit((U32)i+1)*/ + (i==1));
@ -1690,7 +1875,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
if (depth>=1)
while (ip<ilimit) {
ip ++;
for (U32 i=repStart; i<repNum; i++)
for (U32 i=0; i<ZSTD_REP_NUM; i++)
if (MEM_read32(ip) == MEM_read32(ip - rep[i])) {
size_t const mlRep = ZSTD_count(ip+MINMATCH, ip+MINMATCH-rep[i], iend) + MINMATCH;
int const gain2 = (int)(mlRep * 3);
@ -1710,7 +1895,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
for (U32 i=repStart; i<repNum; i++)
for (U32 i=0; i<ZSTD_REP_NUM; i++)
if (MEM_read32(ip) == MEM_read32(ip - rep[i])) {
size_t const ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-rep[i], iend) + MINMATCH;
int const gain2 = (int)(ml2 * 4);
@ -1736,7 +1921,6 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
}
/* store sequence */
_storeSequence:
{
if (offset >= ZSTD_REP_NUM) {
rep[2] = rep[1];
@ -1791,7 +1975,7 @@ static void ZSTD_compressBlock_lazy(ZSTD_CCtx* ctx, const void* src, size_t srcS
static void ZSTD_compressBlock_greedy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 0);
ZSTD_compressBlock_greedy_generic(ctx, src, srcSize);
}
@ -1815,7 +1999,6 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
const U32 maxSearches = 1 << ctx->params.cParams.searchLog;
const U32 mls = ctx->params.cParams.searchLength;
const U32 repNum = (ctx->params.cParams.strategy == ZSTD_greedy) ? 1 : ZSTD_REP_NUM;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
@ -1838,7 +2021,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
U32 current = (U32)(ip-base);
/* check repCode */
for (U32 i=0; i<repNum; i++) {
for (U32 i=0; i<ZSTD_REP_NUM; i++) {
const U32 repIndex = (U32)(current - rep[i]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
@ -1849,7 +2032,6 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
if (matchLength==0) {
offset = i;
matchLength = ZSTD_count_2segments(ip+MINMATCH, repMatch+MINMATCH, iend, repEnd, prefixStart) + MINMATCH;
if (depth==0) goto _storeSequence;
} else {
size_t mlRep = ZSTD_count_2segments(ip+MINMATCH, repMatch+MINMATCH, iend, repEnd, prefixStart) + MINMATCH;
int gain2 = (int)(mlRep * 3 /*- ZSTD_highbit((U32)i+1)*/ + (i==1));
@ -1877,7 +2059,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
ip ++;
current++;
/* check repCode */
for (U32 i=0; i<repNum; i++) {
for (U32 i=0; i<ZSTD_REP_NUM; i++) {
const U32 repIndex = (U32)(current - rep[i]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
@ -1907,7 +2089,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
ip ++;
current++;
/* check repCode */
for (U32 i=0; i<repNum; i++) {
for (U32 i=0; i<ZSTD_REP_NUM; i++) {
const U32 repIndex = (U32)(current - rep[i]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
@ -1943,7 +2125,6 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
}
/* store sequence */
_storeSequence:
{
if (offset >= ZSTD_REP_NUM) {
rep[2] = rep[1];
@ -1974,7 +2155,7 @@ _storeSequence:
void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 0);
ZSTD_compressBlock_greedy_extDict_generic(ctx, src, srcSize);
}
static void ZSTD_compressBlock_lazy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)