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Add logic to handle ZSTD_sequenceRange

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senhuang42 2020-10-28 13:28:27 -04:00
parent 85822ddd53
commit 337fac216d
1 changed files with 53 additions and 15 deletions
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68
lib/compress/zstd_compress.c
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@ -4521,33 +4521,71 @@ static void ZSTD_updateSequenceRange(ZSTD_sequenceRange* sequenceRange, size_t n
sequenceRange->endPosInSequence = endPosInSequence; sequenceRange->endPosInSequence = endPosInSequence;
} }
/* Returns 0 on success, otherwise ZSTD error code */ /* Returns size of sequences range copied, otherwise ZSTD error code */
static size_t ZSTD_copySequencesToSeqStore(ZSTD_CCtx* zc, static size_t ZSTD_copySequencesToSeqStore(ZSTD_CCtx* zc, const ZSTD_sequenceRange* seqRange,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize, const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* src, size_t srcSize) { const void* src, size_t srcSize) {
DEBUGLOG(4, "ZSTD_copySequencesToSeqStore: numSeqs: %zu", inSeqsSize); DEBUGLOG(4, "ZSTD_copySequencesToSeqStore: numSeqs: %zu", inSeqsSize);
size_t idx = 0; size_t idx = seqRange->startIdx;
BYTE const* istart = (BYTE const*)src; BYTE const* istart = (BYTE const*)src;
BYTE const* ip = (BYTE const*)src; BYTE const* ip = (BYTE const*)src;
const BYTE* const iend = ip + srcSize; const BYTE* const iend = ip + srcSize;
ZSTD_resetSeqStore(&zc->seqStore); ZSTD_resetSeqStore(&zc->seqStore);
for (; idx < inSeqsSize; ++idx) { for (; idx < inSeqsSize && idx <= seqRange->endIdx; ++idx) {
if (inSeqs[idx].matchLength == inSeqs[idx].offset == 0) {
/* Handle last literals case */
size_t lastLLSize = inSeqs[idx].litLength;
if (lastLLSize > 0) {
DEBUGLOG(4, "Storing last literals: %u bytes", lastLLSize);
const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
}
break;
}
U32 litLength = inSeqs[idx].litLength; U32 litLength = inSeqs[idx].litLength;
U32 matchLength = inSeqs[idx].matchLength; U32 matchLength = inSeqs[idx].matchLength;
U32 offCode = inSeqs[idx].offset + ZSTD_REP_MOVE; U32 offCode = inSeqs[idx].offset + ZSTD_REP_MOVE;
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small!");
DEBUGLOG(4, "Seqstore idx: %zu, seq: (ll: %u, ml: %u, of: %u)", idx, litLength, matchLength, offCode); DEBUGLOG(4, "Seqstore idx: %zu, seq: (ll: %u, ml: %u, of: %u)", idx, litLength, matchLength, offCode);
/* Adjust litLength and matchLength for the sequence at startIdx */
if (idx == seqRange->startIdx) {
U32 posInSequence = seqRange->startPosInSequence;
DEBUGLOG(4, "Reached startIdx. idx: %u PIS: %u", idx, posInSequence);
assert(posInSequence <= litLength + matchLength);
if (posInSequence >= litLength) {
litLength = 0;
posInSequence -= litLength;
} else {
litLength -= posInSequence;
}
matchLength -= posInSequence;
if (matchLength <= MINMATCH) {
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small! Start Idx");
}
DEBUGLOG(4, "final ll:%u ml: %u", litLength, matchLength);
}
/* Adjust litLength and matchLength for the sequence at endIdx */
// TODO: This is not quite right - we should be storing the inverse of startIdx
if (idx == seqRange->endIdx) {
U32 posInSequence = seqRange->endPosInSequence;
DEBUGLOG(4, "Reached endIdx. idx: %u PIS: %u", idx, posInSequence);
assert(posInSequence <= litLength + matchLength);
if (posInSequence < litLength) {
litLength = posInSequence;
matchLength = 0;
} else {
matchLength = posInSequence - litLength;
if (matchLength <= MINMATCH) {
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small! Start Idx");
}
}
DEBUGLOG(4, "final ll:%u ml: %u", litLength, matchLength);
}
/* ML == 0 and Offset == 0 (or offCode == ZSTD_REP_MOVE) implies we have a last literals of block */
if (matchLength == 0 && offCode == 0) {
/* Handle last literals case */
if (litLength > 0) {
DEBUGLOG(4, "Storing last literals: %u bytes, idx: %u", litLength, idx);
const BYTE* const lastLiterals = (const BYTE*)src + srcSize - litLength;
ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, litLength);
}
break;
}
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small!");
if (inSeqs[idx].rep) { if (inSeqs[idx].rep) {
ZSTD_storeSeq(&zc->seqStore, litLength, ip, iend, inSeqs[idx].rep - 1, matchLength - MINMATCH); ZSTD_storeSeq(&zc->seqStore, litLength, ip, iend, inSeqs[idx].rep - 1, matchLength - MINMATCH);
} else { } else {