ddidderr/zstd-rs
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introduced ZSTD_REP_MOVE and ZSTD_REP_INIT

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inikep
2016-03-18 11:03:43 +01:00
parent c56e32e782
commit eca2ec0b3b
4 changed files with 54 additions and 32 deletions
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lib/zstd_compress.c
+18 -18
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@@ -993,7 +993,7 @@ void ZSTD_compressBlock_fast_generic(ZSTD_CCtx* zc,
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_NUM - 1, mlCode);
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mlCode);
}
/* match found */
@@ -1105,7 +1105,7 @@ static void ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
offset = current - matchIndex;
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_NUM - 1, mlCode);
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mlCode);
} }
/* found a match : store it */
@@ -1563,8 +1563,8 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
/* init */
U32 rep[ZSTD_REP_NUM+1];
for (int i=0; i<ZSTD_REP_NUM+1; i++)
U32 rep[ZSTD_REP_INIT];
for (int i=0; i<ZSTD_REP_INIT; i++)
rep[i]=REPCODE_STARTVALUE;
ZSTD_resetSeqStore(seqStorePtr);
@@ -1598,7 +1598,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
size_t offsetFound = 99999999;
size_t ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound + (ZSTD_REP_NUM - 1);
matchLength = ml2, start = ip, offset=offsetFound + ZSTD_REP_MOVE;
}
if (matchLength < MINMATCH) {
@@ -1624,7 +1624,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 4);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2 + (ZSTD_REP_NUM - 1), start = ip;
matchLength = ml2, offset = offset2 + ZSTD_REP_MOVE, start = ip;
continue; /* search a better one */
} }
@@ -1645,7 +1645,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 7);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2 + (ZSTD_REP_NUM - 1), start = ip;
matchLength = ml2, offset = offset2 + ZSTD_REP_MOVE, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
@@ -1653,7 +1653,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
/* catch up */
if (offset >= ZSTD_REP_NUM) {
while ((start>anchor) && (start>base+offset-(ZSTD_REP_NUM-1)) && (start[-1] == start[-1-offset+(ZSTD_REP_NUM-1)])) /* only search for offset within prefix */
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++; }
}
@@ -1666,7 +1666,7 @@ _storeSequence:
rep[3] = rep[2];
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - (ZSTD_REP_NUM - 1);
rep[0] = offset - ZSTD_REP_MOVE;
#else
if (kSlotNew < 3)
rep[3] = rep[2];
@@ -1674,7 +1674,7 @@ _storeSequence:
rep[2] = rep[1];
if (kSlotNew < 1)
rep[1] = rep[0];
rep[kSlotNew] = offset - (ZSTD_REP_NUM - 1);
rep[kSlotNew] = offset - ZSTD_REP_MOVE;
#endif
} else {
if (offset != 0) {
@@ -1691,7 +1691,7 @@ _storeSequence:
}
#else
if (offset >= ZSTD_REP_NUM) {
rep[1] = rep[0]; rep[0] = offset - (ZSTD_REP_NUM - 1);
rep[1] = rep[0]; rep[0] = offset - ZSTD_REP_MOVE;
}
#endif
size_t litLength = start - anchor;
@@ -1764,8 +1764,8 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
printf("ZSTD_compressBlock_lazy_extDict_generic reps not implemented!\n"); exit(1);
/* init */
U32 rep[ZSTD_REP_NUM];
for (int i=0; i<ZSTD_REP_NUM; i++)
U32 rep[ZSTD_REP_INIT];
for (int i=0; i<ZSTD_REP_INIT; i++)
rep[i]=REPCODE_STARTVALUE;
ZSTD_resetSeqStore(seqStorePtr);
if ((ip - prefixStart) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
@@ -1795,7 +1795,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
size_t offsetFound = 99999999;
size_t ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound + (ZSTD_REP_NUM - 1);
matchLength = ml2, start = ip, offset=offsetFound + ZSTD_REP_MOVE;
}
if (matchLength < MINMATCH) {
@@ -1831,7 +1831,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 4);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2 + (ZSTD_REP_NUM - 1), start = ip;
matchLength = ml2, offset = offset2 + ZSTD_REP_MOVE, start = ip;
continue; /* search a better one */
} }
@@ -1862,7 +1862,7 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 7);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2 + (ZSTD_REP_NUM - 1), start = ip;
matchLength = ml2, offset = offset2 + ZSTD_REP_MOVE, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
@@ -1870,11 +1870,11 @@ void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
/* catch up */
if (offset >= ZSTD_REP_NUM) {
U32 matchIndex = (U32)((start-base) - (offset - (ZSTD_REP_NUM - 1)));
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++; } /* catch up */
rep[1] = rep[0]; rep[0] = offset - (ZSTD_REP_NUM - 1);
rep[1] = rep[0]; rep[0] = offset - ZSTD_REP_MOVE;
}
/* store sequence */