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Interleave Prefix and Dict Searches

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This commit is contained in:
W. Felix Handte
2018-05-25 13:13:57 -04:00
parent 1850025156
commit 88b733b380
1 changed files with 15 additions and 11 deletions
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lib/compress/zstd_double_fast.c
+15 -11
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@@ -149,6 +149,20 @@ size_t ZSTD_compressBlock_doubleFast_generic(
goto _match_found; goto _match_found;
} }
/* check dictMatchState long match */
if (dictMode == ZSTD_dictMatchState) {
U32 const dictMatchIndexL = dictHashLong[h2];
const BYTE* dictMatchL = dictBase + dictMatchIndexL;
assert(dictMatchL < dictEnd);
if (dictMatchL > dictLowest && MEM_read64(dictMatchL) == MEM_read64(ip)) {
mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
offset = (U32)(current - dictMatchIndexL - dictIndexDelta);
while (((ip>anchor) & (dictMatchL>dictLowest)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
goto _match_found;
}
}
/* check prefix short match */ /* check prefix short match */
if ( (matchIndexS > prefixLowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) { if ( (matchIndexS > prefixLowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) {
size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8); size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
@@ -170,22 +184,12 @@ size_t ZSTD_compressBlock_doubleFast_generic(
goto _match_found; goto _match_found;
} }
/* check dictMatchState matches */ /* check dictMatchState short match */
if (dictMode == ZSTD_dictMatchState) { if (dictMode == ZSTD_dictMatchState) {
U32 const dictMatchIndexL = dictHashLong[h2];
U32 const dictMatchIndexS = dictHashSmall[h]; U32 const dictMatchIndexS = dictHashSmall[h];
const BYTE* dictMatchL = dictBase + dictMatchIndexL;
const BYTE* dictMatchS = dictBase + dictMatchIndexS; const BYTE* dictMatchS = dictBase + dictMatchIndexS;
assert(dictMatchL < dictEnd);
assert(dictMatchS < dictEnd); assert(dictMatchS < dictEnd);
if (dictMatchL > dictLowest && MEM_read64(dictMatchL) == MEM_read64(ip)) {
mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
offset = (U32)(current - dictMatchIndexL - dictIndexDelta);
while (((ip>anchor) & (dictMatchL>dictLowest)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
goto _match_found;
}
if (dictMatchS > dictLowest && MEM_read32(dictMatchS) == MEM_read32(ip)) { if (dictMatchS > dictLowest && MEM_read32(dictMatchS) == MEM_read32(ip)) {
size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8); size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
U32 const dictMatchIndexL3 = dictHashLong[hl3]; U32 const dictMatchIndexL3 = dictHashLong[hl3];