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updated documentation on validateSequence

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This commit is contained in:
Yann Collet
2024-12-20 10:36:59 -08:00
parent 1f6d6815c3
commit d2d0fdac42
2 changed files with 15 additions and 15 deletions
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lib/compress/zstd_compress.c
+3 -3
View File
@@ -6585,11 +6585,11 @@ size_t ZSTD_compress2(ZSTD_CCtx* cctx,
}
/* ZSTD_validateSequence() :
* @offCode : is presumed to follow format required by ZSTD_storeSeq()
* @offBase : must use the format required by ZSTD_storeSeq()
* @returns a ZSTD error code if sequence is not valid
*/
static size_t
ZSTD_validateSequence(U32 offCode, U32 matchLength, U32 minMatch,
ZSTD_validateSequence(U32 offBase, U32 matchLength, U32 minMatch,
size_t posInSrc, U32 windowLog, size_t dictSize, int useSequenceProducer)
{
U32 const windowSize = 1u << windowLog;
@@ -6600,7 +6600,7 @@ ZSTD_validateSequence(U32 offCode, U32 matchLength, U32 minMatch,
*/
size_t const offsetBound = posInSrc > windowSize ? (size_t)windowSize : posInSrc + (size_t)dictSize;
size_t const matchLenLowerBound = (minMatch == 3 || useSequenceProducer) ? 3 : 4;
RETURN_ERROR_IF(offCode > OFFSET_TO_OFFBASE(offsetBound), externalSequences_invalid, "Offset too large!");
RETURN_ERROR_IF(offBase > OFFSET_TO_OFFBASE(offsetBound), externalSequences_invalid, "Offset too large!");
/* Validate maxNbSeq is large enough for the given matchLength and minMatch */
RETURN_ERROR_IF(matchLength < matchLenLowerBound, externalSequences_invalid, "Matchlength too small for the minMatch");
return 0;
lib/zstd.h
+12 -12
View File
@@ -1635,11 +1635,11 @@ ZSTDLIB_STATIC_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, si
* the block size derived from the cctx, and sequences may be split. This is the default setting.
*
* If ZSTD_c_blockDelimiters == ZSTD_sf_explicitBlockDelimiters, the array of ZSTD_Sequence is expected to contain
* block delimiters (defined in ZSTD_Sequence). Behavior is undefined if no block delimiters are provided.
* valid block delimiters (defined in ZSTD_Sequence). Behavior is undefined if no block delimiters are provided.
*
* If ZSTD_c_validateSequences == 0, this function will blindly accept the sequences provided. Invalid sequences cause undefined
* behavior. If ZSTD_c_validateSequences == 1, then if sequence is invalid (see doc/zstd_compression_format.md for
* specifics regarding offset/matchlength requirements) then the function will bail out and return an error.
* If ZSTD_c_validateSequences == 0, this function blindly accepts the Sequences provided. Invalid Sequences cause undefined
* behavior. If ZSTD_c_validateSequences == 1, then the function will detect invalid Sequences (see doc/zstd_compression_format.md for
* specifics regarding offset/matchlength requirements) and then bail out and return an error.
*
* In addition to the two adjustable experimental params, there are other important cctx params.
* - ZSTD_c_minMatch MUST be set as less than or equal to the smallest match generated by the match finder. It has a minimum value of ZSTD_MINMATCH_MIN.
@@ -1662,10 +1662,10 @@ ZSTD_compressSequences(ZSTD_CCtx* cctx,
/*! ZSTD_compressSequencesAndLiterals() :
* This is a variant of ZSTD_compressSequences() which,
* instead of receiving (src,srcSize) as input parameter, receives (literals,litSize),
* aka all literals already extracted and laid out into a single continuous buffer.
* aka all the literals, already extracted and laid out into a single continuous buffer.
* This can be useful if the process generating the sequences also happens to generate the buffer of literals,
* thus skipping an extraction + caching stage.
* It's merely a speed optimization when the right conditions are met,
* It's a speed optimization, useful when the right conditions are met,
* but it also features the following limitations:
* - Only supports explicit delimiter mode
* - Supports 1 block only (max input 128 KB)
@@ -2172,17 +2172,17 @@ ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const vo
/* ZSTD_c_validateSequences
* Default is 0 == disabled. Set to 1 to enable sequence validation.
*
* For use with sequence compression API: ZSTD_compressSequences().
* Designates whether or not we validate sequences provided to ZSTD_compressSequences()
* For use with sequence compression API: ZSTD_compressSequences*().
* Designates whether or not provided sequences are validated within ZSTD_compressSequences*()
* during function execution.
*
* Without validation, providing a sequence that does not conform to the zstd spec will cause
* undefined behavior, and may produce a corrupted block.
* When Sequence validation is disabled (default), Sequences are compressed as-is,
* so they must correct, otherwise it would result in a corruption error.
*
* With validation enabled, if sequence is invalid (see doc/zstd_compression_format.md for
* Sequence validation adds some protection, by ensuring that all values respect boundary conditions.
* If a Sequence is detected invalid (see doc/zstd_compression_format.md for
* specifics regarding offset/matchlength requirements) then the function will bail out and
* return an error.
*
*/
#define ZSTD_c_validateSequences ZSTD_c_experimentalParam12