ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Implemented repOffset "minus 1" on ll==0

Browse Source
This commit is contained in:
Yann Collet
2016-07-31 04:01:57 +02:00
parent 8f29e8e0e4
commit 917fe188f1
3 changed files with 26 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/compress/zstd_opt.h
+16 -12
View File
@@ -453,7 +453,7 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
/* check repCode */
{ U32 i;
for (i=0; i<ZSTD_REP_CHECK; i++) {
for (i=(ip == anchor); i<ZSTD_REP_CHECK; i++) {
if ((rep[i]<(U32)(ip-prefixStart))
&& (MEM_readMINMATCH(ip, minMatch) == MEM_readMINMATCH(ip - rep[i], minMatch))) {
mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-rep[i], iend) + minMatch;
@@ -462,7 +462,7 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
goto _storeSequence;
}
best_off = (i<=1 && ip == anchor) ? 1-i : i;
best_off = i - (ip == anchor);
do {
price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH);
if (mlen > last_pos || price < opt[mlen].price)
@@ -544,9 +544,9 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
best_mlen = minMatch;
{ U32 i;
for (i=0; i<ZSTD_REP_CHECK; i++) {
for (i=(opt[cur].mlen != 1); i<ZSTD_REP_CHECK; i++) { /* check rep */
if ((opt[cur].rep[i]<(U32)(inr-prefixStart))
&& (MEM_readMINMATCH(inr, minMatch) == MEM_readMINMATCH(inr - opt[cur].rep[i], minMatch))) { /* check rep */
&& (MEM_readMINMATCH(inr, minMatch) == MEM_readMINMATCH(inr - opt[cur].rep[i], minMatch))) {
mlen = (U32)ZSTD_count(inr+minMatch, inr+minMatch - opt[cur].rep[i], iend) + minMatch;
ZSTD_LOG_PARSER("%d: Found REP %d/%d mlen=%d off=%d rep=%d opt[%d].off=%d\n", (int)(inr-base), i, ZSTD_REP_NUM, mlen, i, opt[cur].rep[i], cur, opt[cur].off);
@@ -556,7 +556,9 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
goto _storeSequence;
}
best_off = (i<=1 && opt[cur].mlen != 1) ? 1-i : i;
//best_off = ((i<=1) & (opt[cur].mlen != 1)) ? 1-i : i;
best_off = i - (opt[cur].mlen != 1);
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
@@ -661,7 +663,8 @@ _storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength == 0 && offset<=1) offset = 1-offset;
if ((litLength == 0) & (offset==0)) offset = rep[1]; /* protection, but should never happen */
if ((litLength == 0) & (offset<=2)) offset--;
}
ZSTD_LOG_ENCODE("%d/%d: ENCODE literals=%d mlen=%d off=%d rep[0]=%d rep[1]=%d\n", (int)(ip-base), (int)(iend-base), (int)(litLength), (int)mlen, (int)(offset), (int)rep[0], (int)rep[1]);
@@ -746,7 +749,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
/* check repCode */
{ U32 i;
for (i=0; i<ZSTD_REP_CHECK; i++) {
for (i = (ip==anchor); i<ZSTD_REP_CHECK; i++) {
const U32 repIndex = (U32)(current - rep[i]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
@@ -763,7 +766,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
goto _storeSequence;
}
best_off = (i<=1 && ip == anchor) ? 1-i : i;
best_off = i - (ip==anchor);
litlen = opt[0].litlen;
do {
price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH);
@@ -849,7 +852,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
best_mlen = 0;
{ U32 i;
for (i=0; i<ZSTD_REP_CHECK; i++) {
for (i = (opt[cur].mlen != 1); i<ZSTD_REP_CHECK; i++) {
const U32 repIndex = (U32)(current+cur - opt[cur].rep[i]);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
@@ -867,7 +870,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
goto _storeSequence;
}
best_off = (i<=1 && opt[cur].mlen != 1) ? 1-i : i;
best_off = i - (opt[cur].mlen != 1);
if (opt[cur].mlen == 1) {
litlen = opt[cur].litlen;
if (cur > litlen) {
@@ -973,8 +976,9 @@ _storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
if (offset != 1) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = best_off;
}
if (litLength == 0 && offset<=1) offset = 1-offset;
}
if ((litLength==0) & (offset==0)) offset = rep[1]; /* protection, but should never happen */
if ((litLength==0) & (offset<=2)) offset --;
}
ZSTD_LOG_ENCODE("%d/%d: ENCODE literals=%d mlen=%d off=%d rep[0]=%d rep[1]=%d\n", (int)(ip-base), (int)(iend-base), (int)(litLength), (int)mlen, (int)(offset), (int)rep[0], (int)rep[1]);
lib/decompress/zstd_decompress.c
+2 -2
View File
@@ -627,9 +627,9 @@ static seq_t ZSTD_decodeSequence(seqState_t* seqState)
}
if (ofCode <= 1) {
if ((llCode == 0) & (offset <= 1)) offset = 1-offset;
offset += (llCode==0);
if (offset) {
size_t const temp = seqState->prevOffset[offset];
size_t const temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset = temp;