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Code Issues Releases 1 Activity

minor bt improvements

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This commit is contained in:
Yann Collet 2015-11-07 01:13:31 +01:00
parent a81d9ac42d
commit f48e35c206
7 changed files with 43 additions and 20 deletions
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2
Makefile
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@ -32,7 +32,7 @@
# ################################################################
# Version number
export VERSION := 0.3.4
export VERSION := 0.3.5
PRGDIR = programs
ZSTDDIR = lib

3
NEWS
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@ -1,3 +1,6 @@
v0.3.5
minor generic compression improvements
v0.3.4
Faster fast cLevels

2
lib/zstd.h
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@ -48,7 +48,7 @@ extern "C" {
***************************************/
#define ZSTD_VERSION_MAJOR 0 /* for breaking interface changes */
#define ZSTD_VERSION_MINOR 3 /* for new (non-breaking) interface capabilities */
#define ZSTD_VERSION_RELEASE 4 /* for tweaks, bug-fixes, or development */
#define ZSTD_VERSION_RELEASE 5 /* for tweaks, bug-fixes, or development */
#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
unsigned ZSTD_versionNumber (void);

50
lib/zstdhc.c
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@ -161,7 +161,7 @@ static size_t ZSTD_HC_resetCCtx_advanced (ZSTD_HC_CCtx* zc,
zc->seqStore.buffer = (void*) (zc->contentTable + ((size_t)1 << contentLog));
}
zc->nextToUpdate = 0;
zc->nextToUpdate = 1;
zc->end = NULL;
zc->base = NULL;
zc->dictBase = NULL;
@ -316,7 +316,7 @@ size_t ZSTD_HC_compressBlock_fast(ZSTD_HC_CCtx* ctx,
***************************************/
/** ZSTD_HC_insertBt1 : add one ptr to tree
@ip : assumed <= iend-8 */
static void ZSTD_HC_insertBt1(ZSTD_HC_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares)
static U32 ZSTD_HC_insertBt1(ZSTD_HC_CCtx* zc, const BYTE* ip, const U32 mls, const BYTE* const iend, U32 nbCompares)
{
U32* const hashTable = zc->hashTable;
const U32 hashLog = zc->params.hashLog;
@ -327,48 +327,61 @@ static void ZSTD_HC_insertBt1(ZSTD_HC_CCtx* zc, const BYTE* const ip, const U32
U32 matchIndex = hashTable[h];
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const base = zc->base;
const U32 current = (U32)(ip-base);
const BYTE* match = base + matchIndex;
U32 current = (U32)(ip-base);
const U32 btLow = btMask >= current ? 0 : current - btMask;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 dummy32; /* to be nullified at the end */
const U32 windowSize = 1 << zc->params.windowLog;
const U32 windowLow = windowSize >= current ? 0 : current - windowSize;
U32 skip = 0;
hashTable[h] = (U32)(ip-base); /* Update Hash Table */
if ( (current-matchIndex == 1) /* RLE */
&& ZSTD_read_ARCH(match) == ZSTD_read_ARCH(ip))
{
size_t cyclicLength = ZSTD_count(ip+sizeof(size_t), match+sizeof(size_t), iend) + sizeof(size_t);
skip = (U32)(cyclicLength - mls); /* > 1 */
ip += skip; /* last of segment */
smallerPtr += 2*skip;
largerPtr += 2*skip;
}
hashTable[h] = (U32)(ip - base); /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow))
{
U32* nextPtr = bt + 2*(matchIndex & btMask);
const BYTE* match = base + matchIndex;
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
match = base + matchIndex;
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* just drop, to guarantee consistency (miss a little bit of compression) */
break; /* just drop , to guarantee consistency (miss a bit of compression; if someone knows better, please tell) */
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 */
if (matchIndex <= btLow) smallerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[1];
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;
if (matchIndex <= btLow) largerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[0];
matchIndex = nextPtr[0];
}
}
*smallerPtr = *largerPtr = 0;
return skip+1;
}
@ -443,18 +456,19 @@ size_t ZSTD_HC_insertBtAndFindBestMatch (
}
static void ZSTD_HC_updateTree(ZSTD_HC_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
static const BYTE* ZSTD_HC_updateTree(ZSTD_HC_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;
//size_t dummy;
for( ; idx < target ; idx++)
ZSTD_HC_insertBt1(zc, base+idx, mls, iend, nbCompares);
for( ; idx < target ; )
idx += ZSTD_HC_insertBt1(zc, base+idx, mls, iend, nbCompares);
//ZSTD_HC_insertBtAndFindBestMatch(zc, base+idx, iend, &dummy, nbCompares, mls);
zc->nextToUpdate = target;
zc->nextToUpdate = idx;
return base + idx;
}
@ -466,7 +480,13 @@ size_t ZSTD_HC_BtFindBestMatch (
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
ZSTD_HC_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
const BYTE* nextToUpdate = ZSTD_HC_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
if (nextToUpdate > ip)
{
/* RLE data */
*offsetPtr = 1;
return ZSTD_count(ip, ip-1, iLimit);
}
return ZSTD_HC_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls);
}

2
lib/zstdhc_static.h
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@ -106,7 +106,7 @@ static const ZSTD_HC_parameters ZSTD_HC_defaultParameters[ZSTD_HC_MAX_CLEVEL+1]
{ 19, 15, 16, 1, 6, ZSTD_HC_fast }, /* level 2 */
{ 20, 18, 20, 1, 6, ZSTD_HC_fast }, /* level 3 */
{ 21, 19, 21, 1, 6, ZSTD_HC_fast }, /* level 4 */
{ 19, 14, 19, 2, 5, ZSTD_HC_greedy }, /* level 5 */
{ 19, 15, 18, 2, 5, ZSTD_HC_greedy }, /* level 5 */
{ 20, 17, 19, 3, 5, ZSTD_HC_greedy }, /* level 6 */
{ 21, 17, 20, 3, 5, ZSTD_HC_lazy }, /* level 7 */
{ 21, 19, 20, 3, 5, ZSTD_HC_lazy }, /* level 8 */

2
programs/Makefile
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@ -30,7 +30,7 @@
# fullbench32: Same as fullbench, but forced to compile in 32-bits mode
# ##########################################################################
VERSION?= 0.3.4
VERSION?= 0.3.5
DESTDIR?=
PREFIX ?= /usr/local

2
programs/zstdcli.c
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@ -70,7 +70,7 @@
**************************************/
#define COMPRESSOR_NAME "zstd command line interface"
#ifndef ZSTD_VERSION
# define ZSTD_VERSION "v0.3.4"
# define ZSTD_VERSION "v0.3.5"
#endif
#define AUTHOR "Yann Collet"
#define WELCOME_MESSAGE "*** %s %i-bits %s, by %s (%s) ***\n", COMPRESSOR_NAME, (int)(sizeof(void*)*8), ZSTD_VERSION, AUTHOR, __DATE__