}
typedef struct {
- U32 idx; /* Index in array of ZSTD_Sequence */
- U32 posInSequence; /* Position within sequence at idx */
- size_t posInSrc; /* Number of bytes given by sequences provided so far */
+ U32 idx; /* Index in array of ZSTD_Sequence */
+ U32 posInSequence; /* Position within sequence at idx */
+ size_t posInSrc; /* Number of bytes given by sequences provided so far */
} ZSTD_sequencePosition;
/* ZSTD_validateSequence() :
repcodes_t updatedRepcodes;
U32 dictSize;
+ DEBUGLOG(5, "ZSTD_copySequencesToSeqStoreExplicitBlockDelim (blockSize = %zu)", blockSize);
+
if (cctx->cdict) {
dictSize = (U32)cctx->cdict->dictContentSize;
} else if (cctx->prefixDict.dict) {
return sequenceCopier;
}
+/* Discover the size of next by searching for the block delimiter.
+ * Note that a block delimiter must exist in this mode,
+ * otherwise it's an input error.
+ * The value retrieved will be later compared to ensure it remains within bounds */
+static size_t
+blockSize_explicitDelimiter(const ZSTD_Sequence* inSeqs, size_t inSeqsSize, ZSTD_sequencePosition seqPos)
+{
+ int end = 0;
+ size_t blockSize = 0;
+ size_t spos = seqPos.idx;
+ assert(spos <= inSeqsSize);
+ while (spos < inSeqsSize) {
+ end = (inSeqs[spos].offset == 0);
+ blockSize += inSeqs[spos].litLength + inSeqs[spos].matchLength;
+ if (end) {
+ if (inSeqs[spos].matchLength != 0)
+ RETURN_ERROR(corruption_detected, "delimiter format error : both matchlength and offset must be == 0");
+ break;
+ }
+ spos++;
+ }
+ if (!end)
+ RETURN_ERROR(corruption_detected, "Reached end of sequences without finding a block delimiter");
+ return blockSize;
+}
+
+/* More a "target" block size */
+static size_t blockSize_noDelimiter(size_t blockSize, size_t remaining)
+{
+ int const lastBlock = (remaining <= blockSize);
+ return lastBlock ? remaining : blockSize;
+}
+
+static size_t determine_blockSize(ZSTD_sequenceFormat_e mode,
+ size_t blockSize, size_t remaining,
+ const ZSTD_Sequence* inSeqs, size_t inSeqsSize, ZSTD_sequencePosition seqPos)
+{
+ DEBUGLOG(6, "determine_blockSize : remainingSize = %zu", remaining);
+ if (mode == ZSTD_sf_noBlockDelimiters)
+ return blockSize_noDelimiter(blockSize, remaining);
+ { size_t const explicitBlockSize = blockSize_explicitDelimiter(inSeqs, inSeqsSize, seqPos);
+ FORWARD_IF_ERROR(explicitBlockSize, "Error while determining block size with explicit delimiters");
+ if (explicitBlockSize > blockSize)
+ RETURN_ERROR(corruption_detected, "sequences incorrectly define a too large block");
+ if (explicitBlockSize > remaining)
+ RETURN_ERROR(srcSize_wrong, "sequences define a frame longer than source");
+ return explicitBlockSize;
+ }
+}
+
/* Compress, block-by-block, all of the sequences given.
*
* Returns the cumulative size of all compressed blocks (including their headers),
const void* src, size_t srcSize)
{
size_t cSize = 0;
- U32 lastBlock;
- size_t blockSize;
- size_t compressedSeqsSize;
size_t remaining = srcSize;
ZSTD_sequencePosition seqPos = {0, 0, 0};
}
while (remaining) {
+ size_t compressedSeqsSize;
size_t cBlockSize;
size_t additionalByteAdjustment;
- lastBlock = remaining <= cctx->blockSize;
- blockSize = lastBlock ? (U32)remaining : (U32)cctx->blockSize;
+ size_t blockSize = determine_blockSize(cctx->appliedParams.blockDelimiters,
+ cctx->blockSize, remaining,
+ inSeqs, inSeqsSize, seqPos);
+ U32 const lastBlock = (blockSize == remaining);
+ assert(blockSize <= remaining);
+ FORWARD_IF_ERROR(blockSize, "Error while trying to determine block size");
ZSTD_resetSeqStore(&cctx->seqStore);
DEBUGLOG(4, "Working on new block. Blocksize: %zu", blockSize);
return cSize;
}
-size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size_t dstCapacity,
+size_t ZSTD_compressSequences(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* src, size_t srcSize)
{
} ZSTD_sequenceFormat_e;
/*! ZSTD_generateSequences() :
- * Generate sequences using ZSTD_compress2, given a source buffer.
+ * Generate sequences using ZSTD_compress2(), given a source buffer.
*
* Each block will end with a dummy sequence
* with offset == 0, matchLength == 0, and litLength == length of last literals.
* litLength may be == 0, and if so, then the sequence of (of: 0 ml: 0 ll: 0)
* simply acts as a block delimiter.
*
- * zc can be used to insert custom compression params.
- * This function invokes ZSTD_compress2
+ * @zc can be used to insert custom compression params.
+ * This function invokes ZSTD_compress2().
*
* The output of this function can be fed into ZSTD_compressSequences() with CCtx
* setting of ZSTD_c_blockDelimiters as ZSTD_sf_explicitBlockDelimiters
* @return : number of sequences generated
*/
-ZSTDLIB_STATIC_API size_t ZSTD_generateSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
- size_t outSeqsSize, const void* src, size_t srcSize);
+ZSTDLIB_STATIC_API size_t
+ZSTD_generateSequences( ZSTD_CCtx* zc,
+ ZSTD_Sequence* outSeqs, size_t outSeqsSize,
+ const void* src, size_t srcSize);
/*! ZSTD_mergeBlockDelimiters() :
* Given an array of ZSTD_Sequence, remove all sequences that represent block delimiters/last literals
* Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused.
* Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly,
* and cannot emit an RLE block that disagrees with the repcode history
- * @return : final compressed size or a ZSTD error.
+ * @return : final compressed size, or a ZSTD error code.
*/
-ZSTDLIB_STATIC_API size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size_t dstSize,
- const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
- const void* src, size_t srcSize);
+ZSTDLIB_STATIC_API size_t
+ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize,
+ const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
+ const void* src, size_t srcSize);
/*! ZSTD_writeSkippableFrame() :
projects / thirdparty / zstd.git / commitdiff
