ddidderr/zstd-rs
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integrate fast mode

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This commit is contained in:
Yann Collet
2015-11-05 18:16:59 +01:00
parent 1f44b3f778
commit f12c1304a8
8 changed files with 41 additions and 27 deletions
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lib/zstd.h
+1 -1
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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 3 /* for tweaks, bug-fixes, or development */
#define ZSTD_VERSION_RELEASE 4 /* 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);
lib/zstdhc.c
+5 -1
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@@ -225,10 +225,12 @@ size_t ZSTD_HC_compressBlock_fast_generic(ZSTD_HC_CCtx* ctx,
const U32 hBits = ctx->params.hashLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const size_t maxDist = ((size_t)1 << ctx->params.windowLog);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart + 1;
const BYTE* anchor = istart;
const BYTE* const lowest = (size_t)(istart-base) > maxDist ? istart-maxDist : base;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
@@ -253,7 +255,9 @@ size_t ZSTD_HC_compressBlock_fast_generic(ZSTD_HC_CCtx* ctx,
hashTable[h] = (U32)(ip-base);
if (MEM_read32(ip-offset_2) == MEM_read32(ip)) match = ip-offset_2;
if (MEM_read32(match) != MEM_read32(ip)) { ip += ((ip-anchor) >> g_searchStrength) + 1; offset_2 = offset_1; continue; }
if ( (match < lowest) ||
(MEM_read32(match) != MEM_read32(ip)) )
{ ip += ((ip-anchor) >> g_searchStrength) + 1; offset_2 = offset_1; continue; }
while ((ip>anchor) && (match>base) && (ip[-1] == match[-1])) { ip--; match--; } /* catch up */
{
lib/zstdhc_static.h
+7 -4
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@@ -51,7 +51,7 @@ typedef enum { ZSTD_HC_fast, ZSTD_HC_greedy, ZSTD_HC_lazy, ZSTD_HC_lazy2, ZSTD_H
typedef struct
{
U32 windowLog; /* largest match distance : impact decompression buffer size */
U32 contentLog; /* full search segment : larger == more compression, slower, more memory*/
U32 contentLog; /* full search segment : larger == more compression, slower, more memory (useless for fast) */
U32 hashLog; /* dispatch table : larger == more memory, faster*/
U32 searchLog; /* nb of searches : larger == more compression, slower*/
U32 searchLength; /* size of matches : larger == faster decompression */
@@ -98,11 +98,11 @@ size_t ZSTD_HC_compressEnd(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize);
/* *************************************
* Pre-defined compression levels
***************************************/
#define ZSTD_HC_MAX_CLEVEL 22
#define ZSTD_HC_MAX_CLEVEL 25
static const ZSTD_HC_parameters ZSTD_HC_defaultParameters[ZSTD_HC_MAX_CLEVEL+1] = {
/* W, C, H, S, L, strat */
{ 18, 12, 14, 1, 4, ZSTD_HC_greedy }, /* level 0 - never used */
{ 18, 12, 14, 1, 4, ZSTD_HC_greedy }, /* level 1 - in fact redirected towards zstd fast */
{ 18, 12, 14, 1, 4, ZSTD_HC_fast }, /* level 0 - never used */
{ 18, 12, 14, 1, 7, ZSTD_HC_fast }, /* level 1 - in fact redirected towards zstd fast */
{ 18, 12, 15, 2, 4, ZSTD_HC_greedy }, /* level 2 */
{ 19, 14, 18, 2, 5, ZSTD_HC_greedy }, /* level 3 */
{ 20, 17, 19, 3, 5, ZSTD_HC_greedy }, /* level 4 */
@@ -124,6 +124,9 @@ static const ZSTD_HC_parameters ZSTD_HC_defaultParameters[ZSTD_HC_MAX_CLEVEL+1]
{ 25, 25, 23, 6, 5, ZSTD_HC_btlazy2 }, /* level 20 */
{ 25, 26, 23, 8, 5, ZSTD_HC_btlazy2 }, /* level 21 */
{ 25, 26, 23, 8, 5, ZSTD_HC_btlazy2 }, /* level 22 */
{ 25, 26, 23, 8, 5, ZSTD_HC_btlazy2 }, /* level 23 */
{ 25, 26, 23, 8, 5, ZSTD_HC_btlazy2 }, /* level 24 */
{ 25, 26, 23, 8, 5, ZSTD_HC_btlazy2 }, /* level 25 */
};