AuroraMiddleware/zstd
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Merge pull request #1050 from terrelln/restore-loadedDictEnd

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Restore setting loadedDictEnd
This commit is contained in:
Yann Collet 2018-03-18 01:03:26 -07:00 committed by GitHub
commit d796a78c92
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3 changed files with 20 additions and 7 deletions
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4
lib/compress/zstd_compress.c
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@ -1931,8 +1931,9 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
ZSTD_reduceIndex(cctx, correction);
if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
else ms->nextToUpdate -= correction;
ms->loadedDictEnd = 0;
}
ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, ms->loadedDictEnd + maxDist);
ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd);
if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
{ size_t cSize = ZSTD_compressBlock_internal(cctx,
@ -2118,6 +2119,7 @@ static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms, ZSTD_CCtx_params
ZSTD_compressionParameters const* cParams = &params->cParams;
ZSTD_window_update(&ms->window, src, srcSize);
ms->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ms->window.base);
if (srcSize <= HASH_READ_SIZE) return 0;

21
lib/compress/zstd_compress_internal.h
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@ -562,15 +562,24 @@ MEM_STATIC U32 ZSTD_window_correctOverflow(ZSTD_window_t* window, U32 cycleLog,
/**
* ZSTD_window_enforceMaxDist():
* Sets lowLimit such that indices earlier than (srcEnd - base) - lowLimit are
* invalid. This allows a simple check index >= lowLimit to see if it is valid.
* Source pointers past srcEnd are not guaranteed to be valid.
* Updates lowLimit so that:
* (srcEnd - base) - lowLimit == maxDist + loadedDictEnd
* This allows a simple check that index >= lowLimit to see if index is valid.
* This must be called before a block compression call, with srcEnd as the block
* source end.
* If loadedDictEndPtr is not NULL, we set it to zero once we update lowLimit.
* This is because dictionaries are allowed to be referenced as long as the last
* byte of the dictionary is in the window, but once they are out of range,
* they cannot be referenced. If loadedDictEndPtr is NULL, we use
* loadedDictEnd == 0.
*/
MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
void const* srcEnd, U32 maxDist)
void const* srcEnd, U32 maxDist,
U32* loadedDictEndPtr)
{
U32 const current = (U32)((BYTE const*)srcEnd - window->base);
if (current > maxDist) {
U32 loadedDictEnd = loadedDictEndPtr != NULL ? *loadedDictEndPtr : 0;
if (current > maxDist + loadedDictEnd) {
U32 const newLowLimit = current - maxDist;
if (window->lowLimit < newLowLimit) window->lowLimit = newLowLimit;
if (window->dictLimit < window->lowLimit) {
@ -578,6 +587,8 @@ MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
window->lowLimit);
window->dictLimit = window->lowLimit;
}
if (loadedDictEndPtr)
*loadedDictEndPtr = 0;
}
}

2
lib/compress/zstd_ldm.c
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@ -514,7 +514,7 @@ size_t ZSTD_ldm_generateSequences(
* * Try invalidation after the sequence generation and test the
* the offset against maxDist directly.
*/
ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist);
ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL);
/* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
newLeftoverSize = ZSTD_ldm_generateSequences_internal(
ldmState, sequences, params, chunkStart, chunkSize);