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minor simplification

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Yann Collet
2024-12-10 16:38:51 -08:00
parent f381665c6a
commit 92747abca3
3 changed files with 34 additions and 32 deletions
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19
doc/zstd_manual.html
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@@ -1376,13 +1376,14 @@ ZSTD_generateSequences(ZSTD_CCtx* zc,
</p></pre><BR> </p></pre><BR>
<pre><b>ZSTDLIB_STATIC_API size_t <pre><b>ZSTDLIB_STATIC_API size_t
ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize, ZSTD_compressSequences(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
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);
</b><p> Compress an array of ZSTD_Sequence, associated with @src buffer, into dst. </b><p> Compress an array of ZSTD_Sequence, associated with @src buffer, into dst.
@src contains the entire input (not just the literals). @src contains the entire input (not just the literals).
If @srcSize > sum(sequence.length), the remaining bytes are considered all literals If @srcSize > sum(sequence.length), the remaining bytes are considered all literals
If a dictionary is included, then the cctx should reference the dict. (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.) If a dictionary is included, then the cctx should reference the dict (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.).
The entire source is compressed into a single frame. The entire source is compressed into a single frame.
The compression behavior changes based on cctx params. In particular: The compression behavior changes based on cctx params. In particular:
@@ -1403,23 +1404,25 @@ ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize,
- ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset - ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset
is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md
Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused. Note: Repcodes are, as of now, always re-calculated within this function, ZSTD_Sequence.rep is effectively unused.
Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly, Dev Note: Once ability to ingest repcodes become available, the explicit block delims mode must respect those repcodes exactly,
and cannot emit an RLE block that disagrees with the repcode history and cannot emit an RLE block that disagrees with the repcode history.
@return : final compressed size, or a ZSTD error code. @return : final compressed size, or a ZSTD error code.
</p></pre><BR> </p></pre><BR>
<pre><b>ZSTDLIB_STATIC_API size_t <pre><b>ZSTDLIB_STATIC_API size_t
ZSTD_compressSequencesAndLiterals( ZSTD_CCtx* cctx, void* dst, size_t dstSize, ZSTD_compressSequencesAndLiterals(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize, const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* literals, size_t litSize); const void* literals, size_t litSize);
</b><p> This is a variant of ZSTD_compressSequences() which, </b><p> This is a variant of ZSTD_compressSequences() which,
instead of receiving (src,srcSize) as input parameter, receives (literals,litSize), instead of receiving (src,srcSize) as input parameter, receives (literals,litSize),
aka all literals already extracted and grouped into a single continuous buffer. aka all 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, This can be useful if the process generating the sequences also happens to generate the buffer of literals,
thus skipping an extraction + caching stage. thus skipping an extraction + caching stage.
To be valid, `litSize` must be equal to the sum of all @.litLength fields in @inSeqs. To be valid, @litSize must be equal to the sum of all @.litLength fields in @inSeqs.
Important: Employing this prototype is incompatible with frame checksum.
@return : final compressed size, or a ZSTD error code. @return : final compressed size, or a ZSTD error code.
</p></pre><BR> </p></pre><BR>

17
lib/compress/zstd_compress.c
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@@ -6887,20 +6887,17 @@ blockSize_explicitDelimiter(const ZSTD_Sequence* inSeqs, size_t inSeqsSize, ZSTD
return blockSize; 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, static size_t determine_blockSize(ZSTD_SequenceFormat_e mode,
size_t blockSize, size_t remaining, size_t blockSize, size_t remaining,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize, ZSTD_SequencePosition seqPos) const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
ZSTD_SequencePosition seqPos)
{ {
DEBUGLOG(6, "determine_blockSize : remainingSize = %zu", remaining); DEBUGLOG(6, "determine_blockSize : remainingSize = %zu", remaining);
if (mode == ZSTD_sf_noBlockDelimiters) if (mode == ZSTD_sf_noBlockDelimiters) {
return blockSize_noDelimiter(blockSize, remaining); /* Note: more a "target" block size */
return MIN(remaining, blockSize);
}
assert(mode == ZSTD_sf_explicitBlockDelimiters);
{ size_t const explicitBlockSize = blockSize_explicitDelimiter(inSeqs, inSeqsSize, seqPos); { size_t const explicitBlockSize = blockSize_explicitDelimiter(inSeqs, inSeqsSize, seqPos);
FORWARD_IF_ERROR(explicitBlockSize, "Error while determining block size with explicit delimiters"); FORWARD_IF_ERROR(explicitBlockSize, "Error while determining block size with explicit delimiters");
if (explicitBlockSize > blockSize) if (explicitBlockSize > blockSize)

14
lib/zstd.h
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@@ -1625,7 +1625,7 @@ ZSTDLIB_STATIC_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, si
* Compress an array of ZSTD_Sequence, associated with @src buffer, into dst. * Compress an array of ZSTD_Sequence, associated with @src buffer, into dst.
* @src contains the entire input (not just the literals). * @src contains the entire input (not just the literals).
* If @srcSize > sum(sequence.length), the remaining bytes are considered all literals * If @srcSize > sum(sequence.length), the remaining bytes are considered all literals
* If a dictionary is included, then the cctx should reference the dict. (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.) * If a dictionary is included, then the cctx should reference the dict (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.).
* The entire source is compressed into a single frame. * The entire source is compressed into a single frame.
* *
* The compression behavior changes based on cctx params. In particular: * The compression behavior changes based on cctx params. In particular:
@@ -1646,13 +1646,14 @@ ZSTDLIB_STATIC_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, si
* - ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset * - ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset
* is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md * is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md
* *
* Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused. * Note: Repcodes are, as of now, always re-calculated within this function, ZSTD_Sequence.rep is effectively unused.
* Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly, * Dev Note: Once ability to ingest repcodes become available, the explicit block delims mode must respect those repcodes exactly,
* and cannot emit an RLE block that disagrees with the repcode history * and cannot emit an RLE block that disagrees with the repcode history.
* @return : final compressed size, or a ZSTD error code. * @return : final compressed size, or a ZSTD error code.
*/ */
ZSTDLIB_STATIC_API size_t ZSTDLIB_STATIC_API size_t
ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize, ZSTD_compressSequences(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
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);
@@ -1668,7 +1669,8 @@ ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize,
* @return : final compressed size, or a ZSTD error code. * @return : final compressed size, or a ZSTD error code.
*/ */
ZSTDLIB_STATIC_API size_t ZSTDLIB_STATIC_API size_t
ZSTD_compressSequencesAndLiterals( ZSTD_CCtx* cctx, void* dst, size_t dstSize, ZSTD_compressSequencesAndLiterals(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const ZSTD_Sequence* inSeqs, size_t inSeqsSize, const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
const void* literals, size_t litSize); const void* literals, size_t litSize);