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This commit is contained in:
W. Felix Handte 2018-05-21 18:27:08 -04:00
parent 582b7f85ed
commit 7ef85e0618
2 changed files with 23 additions and 18 deletions
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24
lib/compress/zstd_compress.c
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@ -1207,11 +1207,12 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
/* We have a choice between copying the dictionary context into the working
* context, or referencing the dictionary context from the working context
* in-place. We decide here which strategy to use. */
int attachDict = ( pledgedSrcSize <= 8 KB
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN )
&& cdict->cParams.strategy == ZSTD_fast
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
cdict->cParams);
const int attachDict = ( pledgedSrcSize <= 8 KB
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN )
&& cdict->cParams.strategy == ZSTD_fast
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
cdict->cParams);
{ unsigned const windowLog = params.cParams.windowLog;
assert(windowLog != 0);
@ -1227,7 +1228,9 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
}
if (attachDict) {
if (cdict->matchState.window.nextSrc - cdict->matchState.window.base == 0) {
const U32 cdictLen = (U32)( cdict->matchState.window.nextSrc
- cdict->matchState.window.base);
if (cdictLen == 0) {
/* don't even attach dictionaries with no contents */
DEBUGLOG(4, "skipping attaching empty dictionary");
} else {
@ -1236,15 +1239,12 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
/* prep working match state so dict matches never have negative indices
* when they are translated to the working context's index space. */
if (cctx->blockState.matchState.window.dictLimit <
(U32)(cdict->matchState.window.nextSrc - cdict->matchState.window.base)) {
if (cctx->blockState.matchState.window.dictLimit < cdictLen) {
cctx->blockState.matchState.window.nextSrc =
cctx->blockState.matchState.window.base +
( cdict->matchState.window.nextSrc
- cdict->matchState.window.base);
cctx->blockState.matchState.window.base + cdictLen;
ZSTD_window_clear(&cctx->blockState.matchState.window);
}
cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
cctx->blockState.matchState.loadedDictEnd = params.forceWindow ? 0 : cdictLen;
}
} else {
DEBUGLOG(4, "copying dictionary into context");

17
lib/compress/zstd_fast.c
View File

@ -74,6 +74,7 @@ size_t ZSTD_compressBlock_fast_generic(
const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ?
prefixLowestIndex - (U32)(dictEnd - dictBase) :
0;
const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
@ -83,13 +84,18 @@ size_t ZSTD_compressBlock_fast_generic(
|| prefixLowestIndex >= (U32)(dictEnd - dictBase));
/* init */
ip += (ip - prefixLowest + dictEnd - dictLowest == 0);
{ U32 const maxRep = dictMode == ZSTD_dictMatchState ?
(U32)(ip - prefixLowest + dictEnd - dictLowest) :
(U32)(ip - prefixLowest);
ip += (dictAndPrefixLength == 0);
if (dictMode == ZSTD_noDict) {
U32 const maxRep = (U32)(ip - prefixLowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
if (dictMode == ZSTD_dictMatchState) {
/* dictMatchState repCode checks don't currently handle repCode == 0
* disabling. */
assert(offset_1 <= dictAndPrefixLength);
assert(offset_2 <= dictAndPrefixLength);
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
@ -169,8 +175,7 @@ size_t ZSTD_compressBlock_fast_generic(
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
&& repIndex2 < prefixLowestIndex ?
const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?
dictBase - dictIndexDelta + repIndex2 :
base + repIndex2;
if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)