update new api presentation in zstd.h and manual
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Yann Collet
parent
c7dcf0f379
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bf99150be3
@ -516,204 +516,6 @@ size_t ZSTD_estimateDDictSize(size_t dictSize, unsigned byReference);
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</b><p> Same as ZSTD_compress_usingCDict(), with fine-tune control over frame parameters
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</p></pre><BR>
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<h3>New experimental advanced parameters API</h3><pre></pre><b><pre></pre></b><BR>
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<pre><b>typedef enum {
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</b>/* compression parameters */<b>
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ZSTD_p_compressionLevel=100, </b>/* Update all compression parameters according to pre-defined cLevel table<b>
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* Default level is 3.
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* Special: value 0 means "do not change cLevel". */
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ZSTD_p_windowLog, </b>/* Maximum allowed back-reference distance, expressed as power of 2.<b>
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* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
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* default value : set through compressionLevel.
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* Special: value 0 means "do not change windowLog". */
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ZSTD_p_hashLog, </b>/* Size of the probe table, as a power of 2.<b>
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* Resulting table size is (1 << (hashLog+2)).
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* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
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* Larger tables improve compression ratio of strategies <= dFast,
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* and improve speed of strategies > dFast.
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* Special: value 0 means "do not change hashLog". */
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ZSTD_p_chainLog, </b>/* Size of the full-search table, as a power of 2.<b>
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* Resulting table size is (1 << (chainLog+2)).
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* Larger tables result in better and slower compression.
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* This parameter is useless when using "fast" strategy.
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* Special: value 0 means "do not change chainLog". */
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ZSTD_p_searchLog, </b>/* Number of search attempts, as a power of 2.<b>
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* More attempts result in better and slower compression.
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* This parameter is useless when using "fast" and "dFast" strategies.
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* Special: value 0 means "do not change searchLog". */
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ZSTD_p_minMatch, </b>/* Minimum size of searched matches (note : repCode matches can be smaller).<b>
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* Larger values make faster compression and decompression, but decrease ratio.
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* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
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* Note that currently, for all strategies < btopt, effective minimum is 4.
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* Note that currently, for all strategies > fast, effective maximum is 6.
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* Special: value 0 means "do not change minMatchLength". */
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ZSTD_p_targetLength, </b>/* Only useful for strategies >= btopt.<b>
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* Length of Match considered "good enough" to stop search.
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* Larger values make compression stronger and slower.
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* Special: value 0 means "do not change targetLength". */
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ZSTD_p_compressionStrategy, </b>/* See ZSTD_strategy enum definition.<b>
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* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
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* The higher the value of selected strategy, the more complex it is,
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* resulting in stronger and slower compression.
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* Special: value 0 means "do not change strategy". */
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#if 0
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ZSTD_p_windowSize, </b>/* Maximum allowed back-reference distance.<b>
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* Can be set to a more precise value than windowLog.
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* Will be transparently reduced to closest possible inferior value
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* (see Zstandard compression format) */
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</b>/* Not ready yet ! */<b>
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#endif
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</b>/* frame parameters */<b>
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ZSTD_p_contentSizeFlag=200, </b>/* Content size is written into frame header _whenever known_ (default:1) */<b>
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ZSTD_p_checksumFlag, </b>/* A 32-bits checksum of content is written at end of frame (default:0) */<b>
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ZSTD_p_dictIDFlag, </b>/* When applicable, dictID of dictionary is provided in frame header (default:1) */<b>
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</b>/* dictionary parameters */<b>
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ZSTD_p_refDictContent=300, </b>/* Content of dictionary content will be referenced, instead of copied (default:0).<b>
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* This avoids duplicating dictionary content.
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* But it also requires that dictionary buffer outlives its user (CDict) */
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</b>/* Not ready yet ! */<b>
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ZSTD_p_rawContentDict, </b>/* load dictionary in "content-only" mode (no header analysis) (default:0) */<b>
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</b>/* question : should there be an option to load dictionary only in zstd format, rejecting others with an error code ? */<b>
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</b>/* multi-threading parameters */<b>
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ZSTD_p_nbThreads=400, </b>/* Select how many threads a compression job can spawn (default:1)<b>
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* More threads improve speed, but also increase memory usage.
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* Can only receive a value > 1 if ZSTD_MULTITHREAD is enabled.
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* Special: value 0 means "do not change nbThreads" */
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ZSTD_p_jobSize, </b>/* Size of a compression job. Each compression job is completed in parallel.<b>
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* 0 means default, which is dynamically determined based on compression parameters.
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* Job size must be a minimum of overlapSize, or 1 KB, whichever is largest
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* The minimum size is automatically and transparently enforced */
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ZSTD_p_overlapSizeLog, </b>/* Size of previous input reloaded at the beginning of each job.<b>
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* 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
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</b>/* advanced parameters - may not remain available after API update */<b>
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ZSTD_p_forceMaxWindow=1100, </b>/* Force back-references to remain < windowSize,<b>
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* even when referencing into Dictionary content
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* default : 0 when using a CDict, 1 when using a Prefix */
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} ZSTD_cParameter;
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</b></pre><BR>
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<pre><b>size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
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</b><p> Set one compression parameter, selected by enum ZSTD_cParameter.
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Note : when `value` is an enum, cast it to unsigned for proper type checking.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
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</b><p> Total input data size to be compressed into a single frame.
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This value will be controlled at the end, and result in error if not respected.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Note 1 : 0 means zero, empty.
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In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
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Note that ZSTD_CONTENTSIZE_UNKNOWN is default value for all new compression jobs.
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Note 2 : If all data is provided and consumed in a single round,
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this value is overriden by srcSize instead.
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
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</b><p> Create an internal CDict from dict buffer.
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Decompression will have to use same buffer.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix,
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meaning "return to no-dictionary mode".
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Note 1 : Dictionary content will be copied internally,
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except if ZSTD_p_refDictContent is set.
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Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
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For this reason, compression parameters cannot be changed anymore after loading a prefix.
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It's also a CPU-heavy operation, with non-negligible impact on latency.
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Note 3 : Dictionary will be used for all future compression jobs.
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To return to "no-dictionary" situation, load a NULL dictionary
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize); </b>/* Not ready yet ! */<b>
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</b><p> Reference a prefix (content-only dictionary) to bootstrap next compression job.
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Decompression will have to use same prefix.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix, meaning "return to no-dictionary mode".
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Note 1 : Prefix buffer is referenced. It must outlive compression job.
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Note 3 : Prefix is only used once. Tables are discarded at end of compression job.
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If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict.
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Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
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For this reason, compression parameters cannot be changed anymore after loading a prefix.
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It's also a CPU-heavy operation, with non-negligible impact on latency.
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</p></pre><BR>
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<pre><b>ZSTD_CDict* ZSTD_CDict_createEmpty(void); </b>/* Not ready yet ! */<b>
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size_t ZSTD_CDict_setParameter(ZSTD_CDict* cdict, ZSTD_cParameter param, unsigned value); </b>/* Not ready yet ! */<b>
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size_t ZSTD_CDict_loadDictionary(ZSTD_CDict* cdict, const void* dict, size_t dictSize); </b>/* Not ready yet ! */<b>
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</b><p> Create a CDict object which is still mutable after creation.
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It's the only one case allowing usage of ZSTD_CDict_setParameter().
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Once all compression parameters are selected,
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it's possible to load the target dictionary, using ZSTD_CDict_loadDictionary().
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Dictionary content will be copied internally (except if ZSTD_p_refDictContent is set).
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After loading the dictionary, no more change is possible.
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The only remaining operation is to free CDict object.
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Note : An unfinished CDict behaves the same as a NULL CDict if referenced into a CCtx.
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
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</b><p> Add a prepared dictionary to cctx, to be used for next compression jobs.
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Note that compression parameters will be enforced from within CDict.
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Currently, they supercede any compression parameter previously set within CCtx.
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The dictionary will remain valid for future compression jobs using same cctx.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Special : adding a NULL CDict means "return to no-dictionary mode".
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Note 1 : Currently, only one dictionary can be managed.
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Adding a new dictionary effectively "discards" any previous one.
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Note 2 : CDict is just referenced, its lifetime must outlive CCtx.
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</p></pre><BR>
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<pre><b>typedef enum {
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ZSTD_e_continue=0, </b>/* collect more data, encoder transparently decides when to output result, for optimal conditions */<b>
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ZSTD_e_flush, </b>/* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */<b>
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ZSTD_e_end </b>/* flush any remaining data and ends current frame. Any future compression starts a new frame. */<b>
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} ZSTD_EndDirective;
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</b></pre><BR>
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<pre><b>size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
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ZSTD_outBuffer* output,
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ZSTD_inBuffer* input,
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ZSTD_EndDirective endOp);
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</b><p> Behave about the same as ZSTD_compressStream. To note :
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- Compression parameters are pushed into CCtx before starting compression, using ZSTD_setCCtxParameter()
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- Compression parameters cannot be changed once compression is started.
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- *dstPos must be <= dstCapacity, *srcPos must be <= srcSize
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- *dspPos and *srcPos will be updated. They are guaranteed to remain below their respective limit.
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- @return provides the amount of data ready to flush within internal buffers
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or an error code, which can be tested using ZSTD_isError().
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if @return != 0, flush is not fully completed, and must be called again to empty internal buffers.
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- after a ZSTD_e_end directive, if internal buffer is not fully flushed,
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only ZSTD_e_end and ZSTD_e_flush operations are allowed.
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It is necessary to fully flush internal buffers
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before changing compression parameters or start a new compression job.
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</p></pre><BR>
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<pre><b>void ZSTD_CCtx_reset(ZSTD_CCtx* cctx); </b>/* Not ready yet ! */<b>
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</b><p> Return a CCtx to clean state.
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Useful after an error, or to interrupt an ongoing compression job and start a new one.
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Any internal data not yet flushed is cancelled.
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Dictionary (if any) is dropped, next compression starts with srcSize==unknown by default.
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It's possible to modify compression parameters after a reset.
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</p></pre><BR>
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<pre><b>size_t ZSTD_compress_generic_simpleArgs (
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ZSTD_CCtx* cctx,
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void* dst, size_t dstCapacity, size_t* dstPos,
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const void* src, size_t srcSize, size_t* srcPos,
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ZSTD_EndDirective endOp);
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</b><p> Same as ZSTD_compress_generic(),
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but using only simple integral types as arguments.
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Argument list is less expressive than ZSTD_{in,out}Buffer,
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but can be helpful for binders to dynamic languages
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which have troubles handling structures containing memory pointers.
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</p></pre><BR>
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<a name="Chapter15"></a><h2>Advanced decompression functions</h2><pre></pre>
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<pre><b>unsigned ZSTD_isFrame(const void* buffer, size_t size);
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@ -931,6 +733,203 @@ void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
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</pre></b><BR>
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<pre><b>typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
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</b></pre><BR>
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<h3>New advanced API (experimental, and compression only)</h3><pre></pre><b><pre></pre></b><BR>
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<pre><b>typedef enum {
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</b>/* compression parameters */<b>
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ZSTD_p_compressionLevel=100, </b>/* Update all compression parameters according to pre-defined cLevel table<b>
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* Default level is ZSTD_CLEVEL_DEFAULT==3.
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* Special: value 0 means "do not change cLevel". */
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ZSTD_p_windowLog, </b>/* Maximum allowed back-reference distance, expressed as power of 2.<b>
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* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
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* default value : set through compressionLevel.
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* Special: value 0 means "do not change windowLog". */
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ZSTD_p_hashLog, </b>/* Size of the probe table, as a power of 2.<b>
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* Resulting table size is (1 << (hashLog+2)).
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* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
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* Larger tables improve compression ratio of strategies <= dFast,
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* and improve speed of strategies > dFast.
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* Special: value 0 means "do not change hashLog". */
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ZSTD_p_chainLog, </b>/* Size of the full-search table, as a power of 2.<b>
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* Resulting table size is (1 << (chainLog+2)).
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* Larger tables result in better and slower compression.
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* This parameter is useless when using "fast" strategy.
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* Special: value 0 means "do not change chainLog". */
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ZSTD_p_searchLog, </b>/* Number of search attempts, as a power of 2.<b>
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* More attempts result in better and slower compression.
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* This parameter is useless when using "fast" and "dFast" strategies.
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* Special: value 0 means "do not change searchLog". */
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ZSTD_p_minMatch, </b>/* Minimum size of searched matches (note : repCode matches can be smaller).<b>
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* Larger values make faster compression and decompression, but decrease ratio.
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* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
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* Note that currently, for all strategies < btopt, effective minimum is 4.
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* Note that currently, for all strategies > fast, effective maximum is 6.
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* Special: value 0 means "do not change minMatchLength". */
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ZSTD_p_targetLength, </b>/* Only useful for strategies >= btopt.<b>
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* Length of Match considered "good enough" to stop search.
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* Larger values make compression stronger and slower.
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* Special: value 0 means "do not change targetLength". */
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ZSTD_p_compressionStrategy, </b>/* See ZSTD_strategy enum definition.<b>
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* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
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* The higher the value of selected strategy, the more complex it is,
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* resulting in stronger and slower compression.
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* Special: value 0 means "do not change strategy". */
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#if 0
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ZSTD_p_windowSize, </b>/* Maximum allowed back-reference distance.<b>
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* Can be set to a more precise value than windowLog.
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* Will be transparently reduced to closest possible inferior value
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* (see Zstandard compression format) */
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</b>/* Not ready yet ! */<b>
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#endif
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</b>/* frame parameters */<b>
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ZSTD_p_contentSizeFlag=200, </b>/* Content size is written into frame header _whenever known_ (default:1) */<b>
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ZSTD_p_checksumFlag, </b>/* A 32-bits checksum of content is written at end of frame (default:0) */<b>
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ZSTD_p_dictIDFlag, </b>/* When applicable, dictID of dictionary is provided in frame header (default:1) */<b>
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</b>/* dictionary parameters */<b>
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ZSTD_p_refDictContent=300, </b>/* Content of dictionary content will be referenced, instead of copied (default:0).<b>
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* This avoids duplicating dictionary content.
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* But it also requires that dictionary buffer outlives its user (CDict) */
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</b>/* Not ready yet ! */<b>
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ZSTD_p_rawContentDict, </b>/* load dictionary in "content-only" mode (no header analysis) (default:0) */<b>
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</b>/* question : should there be an option to load dictionary only in zstd format, rejecting others with an error code ? */<b>
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</b>/* multi-threading parameters */<b>
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ZSTD_p_nbThreads=400, </b>/* Select how many threads a compression job can spawn (default:1)<b>
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* More threads improve speed, but also increase memory usage.
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* Can only receive a value > 1 if ZSTD_MULTITHREAD is enabled.
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* Special: value 0 means "do not change nbThreads" */
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ZSTD_p_jobSize, </b>/* Size of a compression job. Each compression job is completed in parallel.<b>
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* 0 means default, which is dynamically determined based on compression parameters.
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* Job size must be a minimum of overlapSize, or 1 KB, whichever is largest
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* The minimum size is automatically and transparently enforced */
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ZSTD_p_overlapSizeLog, </b>/* Size of previous input reloaded at the beginning of each job.<b>
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* 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
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</b>/* advanced parameters - may not remain available after API update */<b>
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ZSTD_p_forceMaxWindow=1100, </b>/* Force back-references to remain < windowSize,<b>
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* even when referencing into Dictionary content
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* default : 0 when using a CDict, 1 when using a Prefix */
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} ZSTD_cParameter;
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</b></pre><BR>
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<pre><b>size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
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</b><p> Set one compression parameter, selected by enum ZSTD_cParameter.
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Note : when `value` is an enum, cast it to unsigned for proper type checking.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
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</b><p> Total input data size to be compressed as a single frame.
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This value will be controlled at the end, and result in error if not respected.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Note 1 : 0 means zero, empty.
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In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
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Note that ZSTD_CONTENTSIZE_UNKNOWN is default value for new compression jobs.
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Note 2 : If all data is provided and consumed in a single round,
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this value is overriden by srcSize instead.
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
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</b><p> Create an internal CDict from dict buffer.
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Decompression will have to use same buffer.
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@result : 0, or an error code (which can be tested with ZSTD_isError()).
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Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix,
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meaning "return to no-dictionary mode".
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Note 1 : Dictionary content will be copied internally,
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except if ZSTD_p_refDictContent is set.
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Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
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For this reason, compression parameters cannot be changed anymore after loading a prefix.
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It's also a CPU-heavy operation, with non-negligible impact on latency.
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Note 3 : Dictionary will be used for all future compression jobs.
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To return to "no-dictionary" situation, load a NULL dictionary
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</p></pre><BR>
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<pre><b>size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
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</b><p> Ref a prepared dictionary, to be used for all next compression jobs.
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Note that compression parameters are enforced from within CDict,
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and supercede any compression parameter previously set within CCtx.
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The dictionary will remain valid for future compression jobs using same CCtx.
|
||||
@result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
Special : adding a NULL CDict means "return to no-dictionary mode".
|
||||
Note 1 : Currently, only one dictionary can be managed.
|
||||
Adding a new dictionary effectively "discards" any previous one.
|
||||
Note 2 : CDict is just referenced, its lifetime must outlive CCtx.
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize); </b>/* Not ready yet ! */<b>
|
||||
</b><p> Reference a prefix (content-only dictionary) to bootstrap next compression job.
|
||||
Decompression will have to use same prefix.
|
||||
Prefix is only used once. Tables are discarded at end of compression job.
|
||||
If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict.
|
||||
@result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix, meaning "return to no-dictionary mode".
|
||||
Note 1 : Prefix buffer is referenced. It must outlive compression job.
|
||||
Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
|
||||
It's a CPU-heavy operation, with non-negligible impact on latency.
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>typedef enum {
|
||||
ZSTD_e_continue=0, </b>/* collect more data, encoder transparently decides when to output result, for optimal conditions */<b>
|
||||
ZSTD_e_flush, </b>/* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */<b>
|
||||
ZSTD_e_end </b>/* flush any remaining data and ends current frame. Any future compression starts a new frame. */<b>
|
||||
} ZSTD_EndDirective;
|
||||
</b></pre><BR>
|
||||
<pre><b>size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
|
||||
ZSTD_outBuffer* output,
|
||||
ZSTD_inBuffer* input,
|
||||
ZSTD_EndDirective endOp);
|
||||
</b><p> Behave about the same as ZSTD_compressStream. To note :
|
||||
- Compression parameters are pushed into CCtx before starting compression, using ZSTD_setCCtxParameter()
|
||||
- Compression parameters cannot be changed once compression is started.
|
||||
- *dstPos must be <= dstCapacity, *srcPos must be <= srcSize
|
||||
- *dspPos and *srcPos will be updated. They are guaranteed to remain below their respective limit.
|
||||
- @return provides the minimum amount of data still to flush from internal buffers
|
||||
or an error code, which can be tested using ZSTD_isError().
|
||||
if @return != 0, flush is not fully completed, and must be called again to empty internal buffers.
|
||||
- after a ZSTD_e_end directive, if internal buffer is not fully flushed,
|
||||
only ZSTD_e_end and ZSTD_e_flush operations are allowed.
|
||||
It is necessary to fully flush internal buffers
|
||||
before starting a new compression job, or changing compression parameters.
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>void ZSTD_CCtx_reset(ZSTD_CCtx* cctx); </b>/* Not ready yet ! */<b>
|
||||
</b><p> Return a CCtx to clean state.
|
||||
Useful after an error, or to interrupt an ongoing compression job and start a new one.
|
||||
Any internal data not yet flushed is cancelled.
|
||||
Dictionary (if any) is dropped.
|
||||
It's possible to modify compression parameters after a reset.
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>size_t ZSTD_compress_generic_simpleArgs (
|
||||
ZSTD_CCtx* cctx,
|
||||
void* dst, size_t dstCapacity, size_t* dstPos,
|
||||
const void* src, size_t srcSize, size_t* srcPos,
|
||||
ZSTD_EndDirective endOp);
|
||||
</b><p> Same as ZSTD_compress_generic(),
|
||||
but using only integral types as arguments.
|
||||
Argument list is larger and less expressive than ZSTD_{in,out}Buffer,
|
||||
but can be helpful for binders from dynamic languages
|
||||
which have troubles handling structures containing memory pointers.
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>ZSTD_CDict* ZSTD_CDict_createEmpty(void); </b>/* Not ready yet ! */<b>
|
||||
size_t ZSTD_CDict_setParameter(ZSTD_CDict* cdict, ZSTD_cParameter param, unsigned value); </b>/* Not ready yet ! */<b>
|
||||
size_t ZSTD_CDict_loadDictionary(ZSTD_CDict* cdict, const void* dict, size_t dictSize); </b>/* Not ready yet ! */<b>
|
||||
</b><p> Create a CDict object which is still mutable after creation.
|
||||
It's the only one case allowing usage of ZSTD_CDict_setParameter().
|
||||
Once all compression parameters are selected,
|
||||
it's possible to load the target dictionary, using ZSTD_CDict_loadDictionary().
|
||||
Dictionary content will be copied internally (except if ZSTD_p_refDictContent is set).
|
||||
After loading the dictionary, no more change is possible.
|
||||
The only remaining operation is to free CDict object.
|
||||
Note : An unfinished CDict behaves the same as a NULL CDict if referenced into a CCtx.
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<a name="Chapter20"></a><h2>Block functions</h2><pre>
|
||||
Block functions produce and decode raw zstd blocks, without frame metadata.
|
||||
Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
|
||||
|
||||
@ -15,6 +15,7 @@
|
||||
# define ZSTD_CLEVEL_DEFAULT 3
|
||||
#endif
|
||||
|
||||
|
||||
/*-*************************************
|
||||
* Dependencies
|
||||
***************************************/
|
||||
@ -4021,11 +4022,6 @@ ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long l
|
||||
if (compressionLevel <= 0) compressionLevel = ZSTD_CLEVEL_DEFAULT; /* 0 == default; no negative compressionLevel yet */
|
||||
if (compressionLevel > ZSTD_MAX_CLEVEL) compressionLevel = ZSTD_MAX_CLEVEL;
|
||||
cp = ZSTD_defaultCParameters[tableID][compressionLevel];
|
||||
if (MEM_32bits()) { /* auto-correction, for 32-bits mode */
|
||||
if (cp.windowLog > ZSTD_WINDOWLOG_MAX) cp.windowLog = ZSTD_WINDOWLOG_MAX;
|
||||
if (cp.chainLog > ZSTD_CHAINLOG_MAX) cp.chainLog = ZSTD_CHAINLOG_MAX;
|
||||
if (cp.hashLog > ZSTD_HASHLOG_MAX) cp.hashLog = ZSTD_HASHLOG_MAX;
|
||||
}
|
||||
return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize); /* no need to ensure initial CParams validity */
|
||||
}
|
||||
|
||||
|
||||
465
lib/zstd.h
465
lib/zstd.h
@ -610,238 +610,6 @@ ZSTDLIB_API size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
|
||||
const ZSTD_CDict* cdict, ZSTD_frameParameters fParams);
|
||||
|
||||
|
||||
/*=== New experimental advanced parameters API ===*/
|
||||
|
||||
/* notes on API design :
|
||||
* In this proposal, parameters are pushed one by one into an existing CCtx,
|
||||
* and then applied on all following compression jobs.
|
||||
* When no parameter is ever provided, CCtx is created with compression level 3.
|
||||
*
|
||||
* Another approach could be to load parameters into an intermediate _opaque_ object.
|
||||
* The object would then be loaded into CCtx (like ZSTD_compress_advanced())
|
||||
* This approach would be compatible with ZSTD_createCDict_advanced().
|
||||
* But it's more cumbersome for CCtx, as it requires to manage an additional object.
|
||||
*
|
||||
* Below proposal push parameters directly into CCtx.
|
||||
* It's a bit more complex for CDict, as advanced version now requires 3 steps.
|
||||
* (basic CDict API remains the same).
|
||||
* See API details below
|
||||
*/
|
||||
|
||||
/* notes on naming convention :
|
||||
* Initially, the API favored names like ZSTD_setCCtxParameter() .
|
||||
* In this proposal, convention is changed towards ZSTD_CCtx_setParameter() .
|
||||
* The main idea is that it identifies more clearly the target object type.
|
||||
* It feels clearer when considering other potential variants :
|
||||
* ZSTD_CDict_setParameter() (rather than ZSTD_setCDictParameter())
|
||||
* ZSTD_DCtx_setParameter() (rather than ZSTD_setDCtxParameter() )
|
||||
* The left variant looks clearer.
|
||||
*/
|
||||
|
||||
typedef enum {
|
||||
/* compression parameters */
|
||||
ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
|
||||
* Default level is 3.
|
||||
* Special: value 0 means "do not change cLevel". */
|
||||
ZSTD_p_windowLog, /* Maximum allowed back-reference distance, expressed as power of 2.
|
||||
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
|
||||
* default value : set through compressionLevel.
|
||||
* Special: value 0 means "do not change windowLog". */
|
||||
ZSTD_p_hashLog, /* Size of the probe table, as a power of 2.
|
||||
* Resulting table size is (1 << (hashLog+2)).
|
||||
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
|
||||
* Larger tables improve compression ratio of strategies <= dFast,
|
||||
* and improve speed of strategies > dFast.
|
||||
* Special: value 0 means "do not change hashLog". */
|
||||
ZSTD_p_chainLog, /* Size of the full-search table, as a power of 2.
|
||||
* Resulting table size is (1 << (chainLog+2)).
|
||||
* Larger tables result in better and slower compression.
|
||||
* This parameter is useless when using "fast" strategy.
|
||||
* Special: value 0 means "do not change chainLog". */
|
||||
ZSTD_p_searchLog, /* Number of search attempts, as a power of 2.
|
||||
* More attempts result in better and slower compression.
|
||||
* This parameter is useless when using "fast" and "dFast" strategies.
|
||||
* Special: value 0 means "do not change searchLog". */
|
||||
ZSTD_p_minMatch, /* Minimum size of searched matches (note : repCode matches can be smaller).
|
||||
* Larger values make faster compression and decompression, but decrease ratio.
|
||||
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
|
||||
* Note that currently, for all strategies < btopt, effective minimum is 4.
|
||||
* Note that currently, for all strategies > fast, effective maximum is 6.
|
||||
* Special: value 0 means "do not change minMatchLength". */
|
||||
ZSTD_p_targetLength, /* Only useful for strategies >= btopt.
|
||||
* Length of Match considered "good enough" to stop search.
|
||||
* Larger values make compression stronger and slower.
|
||||
* Special: value 0 means "do not change targetLength". */
|
||||
ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
|
||||
* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
|
||||
* The higher the value of selected strategy, the more complex it is,
|
||||
* resulting in stronger and slower compression.
|
||||
* Special: value 0 means "do not change strategy". */
|
||||
#if 0
|
||||
ZSTD_p_windowSize, /* Maximum allowed back-reference distance.
|
||||
* Can be set to a more precise value than windowLog.
|
||||
* Will be transparently reduced to closest possible inferior value
|
||||
* (see Zstandard compression format) */
|
||||
/* Not ready yet ! */
|
||||
#endif
|
||||
|
||||
/* frame parameters */
|
||||
ZSTD_p_contentSizeFlag=200, /* Content size is written into frame header _whenever known_ (default:1) */
|
||||
ZSTD_p_checksumFlag, /* A 32-bits checksum of content is written at end of frame (default:0) */
|
||||
ZSTD_p_dictIDFlag, /* When applicable, dictID of dictionary is provided in frame header (default:1) */
|
||||
|
||||
/* dictionary parameters */
|
||||
ZSTD_p_refDictContent=300, /* Content of dictionary content will be referenced, instead of copied (default:0).
|
||||
* This avoids duplicating dictionary content.
|
||||
* But it also requires that dictionary buffer outlives its user (CDict) */
|
||||
/* Not ready yet ! */
|
||||
ZSTD_p_rawContentDict, /* load dictionary in "content-only" mode (no header analysis) (default:0) */
|
||||
/* question : should there be an option to load dictionary only in zstd format, rejecting others with an error code ? */
|
||||
|
||||
/* multi-threading parameters */
|
||||
ZSTD_p_nbThreads=400, /* Select how many threads a compression job can spawn (default:1)
|
||||
* More threads improve speed, but also increase memory usage.
|
||||
* Can only receive a value > 1 if ZSTD_MULTITHREAD is enabled.
|
||||
* Special: value 0 means "do not change nbThreads" */
|
||||
ZSTD_p_jobSize, /* Size of a compression job. Each compression job is completed in parallel.
|
||||
* 0 means default, which is dynamically determined based on compression parameters.
|
||||
* Job size must be a minimum of overlapSize, or 1 KB, whichever is largest
|
||||
* The minimum size is automatically and transparently enforced */
|
||||
ZSTD_p_overlapSizeLog, /* Size of previous input reloaded at the beginning of each job.
|
||||
* 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
|
||||
|
||||
/* advanced parameters - may not remain available after API update */
|
||||
ZSTD_p_forceMaxWindow=1100, /* Force back-references to remain < windowSize,
|
||||
* even when referencing into Dictionary content
|
||||
* default : 0 when using a CDict, 1 when using a Prefix */
|
||||
} ZSTD_cParameter;
|
||||
|
||||
|
||||
/*! ZSTD_CCtx_setParameter() :
|
||||
* Set one compression parameter, selected by enum ZSTD_cParameter.
|
||||
* Note : when `value` is an enum, cast it to unsigned for proper type checking.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()). */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
|
||||
|
||||
/*! ZSTD_CCtx_setPledgedSrcSize() :
|
||||
* Total input data size to be compressed into a single frame.
|
||||
* This value will be controlled at the end, and result in error if not respected.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Note 1 : 0 means zero, empty.
|
||||
* In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
|
||||
* Note that ZSTD_CONTENTSIZE_UNKNOWN is default value for all new compression jobs.
|
||||
* Note 2 : If all data is provided and consumed in a single round,
|
||||
* this value is overriden by srcSize instead. */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
|
||||
|
||||
/*! ZSTD_CCtx_loadDictionary() :
|
||||
* Create an internal CDict from dict buffer.
|
||||
* Decompression will have to use same buffer.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix,
|
||||
* meaning "return to no-dictionary mode".
|
||||
* Note 1 : Dictionary content will be copied internally,
|
||||
* except if ZSTD_p_refDictContent is set.
|
||||
* Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
|
||||
* For this reason, compression parameters cannot be changed anymore after loading a prefix.
|
||||
* It's also a CPU-heavy operation, with non-negligible impact on latency.
|
||||
* Note 3 : Dictionary will be used for all future compression jobs.
|
||||
* To return to "no-dictionary" situation, load a NULL dictionary */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
|
||||
|
||||
/*! ZSTD_CCtx_refPrefix() :
|
||||
* Reference a prefix (content-only dictionary) to bootstrap next compression job.
|
||||
* Decompression will have to use same prefix.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix, meaning "return to no-dictionary mode".
|
||||
* Note 1 : Prefix buffer is referenced. It must outlive compression job.
|
||||
* Note 3 : Prefix is only used once. Tables are discarded at end of compression job.
|
||||
* If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict.
|
||||
* Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
|
||||
* For this reason, compression parameters cannot be changed anymore after loading a prefix.
|
||||
* It's also a CPU-heavy operation, with non-negligible impact on latency. */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize); /* Not ready yet ! */
|
||||
|
||||
|
||||
/*! ZSTD_CDict_createEmpty() :
|
||||
* Create a CDict object which is still mutable after creation.
|
||||
* It's the only one case allowing usage of ZSTD_CDict_setParameter().
|
||||
* Once all compression parameters are selected,
|
||||
* it's possible to load the target dictionary, using ZSTD_CDict_loadDictionary().
|
||||
* Dictionary content will be copied internally (except if ZSTD_p_refDictContent is set).
|
||||
* After loading the dictionary, no more change is possible.
|
||||
* The only remaining operation is to free CDict object.
|
||||
* Note : An unfinished CDict behaves the same as a NULL CDict if referenced into a CCtx.
|
||||
*/
|
||||
ZSTDLIB_API ZSTD_CDict* ZSTD_CDict_createEmpty(void); /* Not ready yet ! */
|
||||
ZSTDLIB_API size_t ZSTD_CDict_setParameter(ZSTD_CDict* cdict, ZSTD_cParameter param, unsigned value); /* Not ready yet ! */
|
||||
ZSTDLIB_API size_t ZSTD_CDict_loadDictionary(ZSTD_CDict* cdict, const void* dict, size_t dictSize); /* Not ready yet ! */
|
||||
|
||||
/*! ZSTD_CCtx_refCDict() :
|
||||
* Add a prepared dictionary to cctx, to be used for next compression jobs.
|
||||
* Note that compression parameters will be enforced from within CDict.
|
||||
* Currently, they supercede any compression parameter previously set within CCtx.
|
||||
* The dictionary will remain valid for future compression jobs using same cctx.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : adding a NULL CDict means "return to no-dictionary mode".
|
||||
* Note 1 : Currently, only one dictionary can be managed.
|
||||
* Adding a new dictionary effectively "discards" any previous one.
|
||||
* Note 2 : CDict is just referenced, its lifetime must outlive CCtx.
|
||||
*/
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
|
||||
|
||||
|
||||
|
||||
typedef enum {
|
||||
ZSTD_e_continue=0, /* collect more data, encoder transparently decides when to output result, for optimal conditions */
|
||||
ZSTD_e_flush, /* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */
|
||||
ZSTD_e_end /* flush any remaining data and ends current frame. Any future compression starts a new frame. */
|
||||
} ZSTD_EndDirective;
|
||||
|
||||
/*! ZSTD_compressStream_generic() :
|
||||
* Behave about the same as ZSTD_compressStream. To note :
|
||||
* - Compression parameters are pushed into CCtx before starting compression, using ZSTD_setCCtxParameter()
|
||||
* - Compression parameters cannot be changed once compression is started.
|
||||
* - *dstPos must be <= dstCapacity, *srcPos must be <= srcSize
|
||||
* - *dspPos and *srcPos will be updated. They are guaranteed to remain below their respective limit.
|
||||
* - @return provides the amount of data ready to flush within internal buffers
|
||||
* or an error code, which can be tested using ZSTD_isError().
|
||||
* if @return != 0, flush is not fully completed, and must be called again to empty internal buffers.
|
||||
* - after a ZSTD_e_end directive, if internal buffer is not fully flushed,
|
||||
* only ZSTD_e_end and ZSTD_e_flush operations are allowed.
|
||||
* It is necessary to fully flush internal buffers
|
||||
* before changing compression parameters or start a new compression job.
|
||||
*/
|
||||
ZSTDLIB_API size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
|
||||
ZSTD_outBuffer* output,
|
||||
ZSTD_inBuffer* input,
|
||||
ZSTD_EndDirective endOp);
|
||||
|
||||
/*! ZSTD_CCtx_reset() :
|
||||
* Return a CCtx to clean state.
|
||||
* Useful after an error, or to interrupt an ongoing compression job and start a new one.
|
||||
* Any internal data not yet flushed is cancelled.
|
||||
* Dictionary (if any) is dropped, next compression starts with srcSize==unknown by default.
|
||||
* It's possible to modify compression parameters after a reset.
|
||||
*/
|
||||
ZSTDLIB_API void ZSTD_CCtx_reset(ZSTD_CCtx* cctx); /* Not ready yet ! */
|
||||
|
||||
|
||||
/*! ZSTD_compress_generic_simpleArgs() :
|
||||
* Same as ZSTD_compress_generic(),
|
||||
* but using only simple integral types as arguments.
|
||||
* Argument list is less expressive than ZSTD_{in,out}Buffer,
|
||||
* but can be helpful for binders to dynamic languages
|
||||
* which have troubles handling structures containing memory pointers.
|
||||
*/
|
||||
size_t ZSTD_compress_generic_simpleArgs (
|
||||
ZSTD_CCtx* cctx,
|
||||
void* dst, size_t dstCapacity, size_t* dstPos,
|
||||
const void* src, size_t srcSize, size_t* srcPos,
|
||||
ZSTD_EndDirective endOp);
|
||||
|
||||
|
||||
|
||||
/*--- Advanced decompression functions ---*/
|
||||
|
||||
/*! ZSTD_isFrame() :
|
||||
@ -1081,6 +849,239 @@ ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t ds
|
||||
typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
|
||||
ZSTDLIB_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
|
||||
|
||||
|
||||
|
||||
/*=== New advanced API (experimental, and compression only) ===*/
|
||||
|
||||
/* notes on API design :
|
||||
* In this proposal, parameters are pushed one by one into an existing CCtx,
|
||||
* and then applied on all subsequent compression jobs.
|
||||
* When no parameter is ever provided, CCtx is created with compression level ZSTD_CLEVEL_DEFAULT.
|
||||
*
|
||||
* This API is intended to replace all others experimental API.
|
||||
* It can basically do all other use cases, and even new ones.
|
||||
* It stands a good chance to become "stable",
|
||||
* after a reasonable testing period.
|
||||
*/
|
||||
|
||||
/* note on naming convention :
|
||||
* Initially, the API favored names like ZSTD_setCCtxParameter() .
|
||||
* In this proposal, convention is changed towards ZSTD_CCtx_setParameter() .
|
||||
* The main idea is that it identifies more clearly the target object type.
|
||||
* It feels clearer when considering other potential variants :
|
||||
* ZSTD_CDict_setParameter() (rather than ZSTD_setCDictParameter())
|
||||
* ZSTD_DCtx_setParameter() (rather than ZSTD_setDCtxParameter() )
|
||||
* The left variant feels clearer.
|
||||
*/
|
||||
|
||||
typedef enum {
|
||||
/* compression parameters */
|
||||
ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
|
||||
* Default level is ZSTD_CLEVEL_DEFAULT==3.
|
||||
* Special: value 0 means "do not change cLevel". */
|
||||
ZSTD_p_windowLog, /* Maximum allowed back-reference distance, expressed as power of 2.
|
||||
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
|
||||
* default value : set through compressionLevel.
|
||||
* Special: value 0 means "do not change windowLog". */
|
||||
ZSTD_p_hashLog, /* Size of the probe table, as a power of 2.
|
||||
* Resulting table size is (1 << (hashLog+2)).
|
||||
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
|
||||
* Larger tables improve compression ratio of strategies <= dFast,
|
||||
* and improve speed of strategies > dFast.
|
||||
* Special: value 0 means "do not change hashLog". */
|
||||
ZSTD_p_chainLog, /* Size of the full-search table, as a power of 2.
|
||||
* Resulting table size is (1 << (chainLog+2)).
|
||||
* Larger tables result in better and slower compression.
|
||||
* This parameter is useless when using "fast" strategy.
|
||||
* Special: value 0 means "do not change chainLog". */
|
||||
ZSTD_p_searchLog, /* Number of search attempts, as a power of 2.
|
||||
* More attempts result in better and slower compression.
|
||||
* This parameter is useless when using "fast" and "dFast" strategies.
|
||||
* Special: value 0 means "do not change searchLog". */
|
||||
ZSTD_p_minMatch, /* Minimum size of searched matches (note : repCode matches can be smaller).
|
||||
* Larger values make faster compression and decompression, but decrease ratio.
|
||||
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
|
||||
* Note that currently, for all strategies < btopt, effective minimum is 4.
|
||||
* Note that currently, for all strategies > fast, effective maximum is 6.
|
||||
* Special: value 0 means "do not change minMatchLength". */
|
||||
ZSTD_p_targetLength, /* Only useful for strategies >= btopt.
|
||||
* Length of Match considered "good enough" to stop search.
|
||||
* Larger values make compression stronger and slower.
|
||||
* Special: value 0 means "do not change targetLength". */
|
||||
ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
|
||||
* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
|
||||
* The higher the value of selected strategy, the more complex it is,
|
||||
* resulting in stronger and slower compression.
|
||||
* Special: value 0 means "do not change strategy". */
|
||||
#if 0
|
||||
ZSTD_p_windowSize, /* Maximum allowed back-reference distance.
|
||||
* Can be set to a more precise value than windowLog.
|
||||
* Will be transparently reduced to closest possible inferior value
|
||||
* (see Zstandard compression format) */
|
||||
/* Not ready yet ! */
|
||||
#endif
|
||||
|
||||
/* frame parameters */
|
||||
ZSTD_p_contentSizeFlag=200, /* Content size is written into frame header _whenever known_ (default:1) */
|
||||
ZSTD_p_checksumFlag, /* A 32-bits checksum of content is written at end of frame (default:0) */
|
||||
ZSTD_p_dictIDFlag, /* When applicable, dictID of dictionary is provided in frame header (default:1) */
|
||||
|
||||
/* dictionary parameters */
|
||||
ZSTD_p_refDictContent=300, /* Content of dictionary content will be referenced, instead of copied (default:0).
|
||||
* This avoids duplicating dictionary content.
|
||||
* But it also requires that dictionary buffer outlives its user (CDict) */
|
||||
/* Not ready yet ! */
|
||||
ZSTD_p_rawContentDict, /* load dictionary in "content-only" mode (no header analysis) (default:0) */
|
||||
/* question : should there be an option to load dictionary only in zstd format, rejecting others with an error code ? */
|
||||
|
||||
/* multi-threading parameters */
|
||||
ZSTD_p_nbThreads=400, /* Select how many threads a compression job can spawn (default:1)
|
||||
* More threads improve speed, but also increase memory usage.
|
||||
* Can only receive a value > 1 if ZSTD_MULTITHREAD is enabled.
|
||||
* Special: value 0 means "do not change nbThreads" */
|
||||
ZSTD_p_jobSize, /* Size of a compression job. Each compression job is completed in parallel.
|
||||
* 0 means default, which is dynamically determined based on compression parameters.
|
||||
* Job size must be a minimum of overlapSize, or 1 KB, whichever is largest
|
||||
* The minimum size is automatically and transparently enforced */
|
||||
ZSTD_p_overlapSizeLog, /* Size of previous input reloaded at the beginning of each job.
|
||||
* 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
|
||||
|
||||
/* advanced parameters - may not remain available after API update */
|
||||
ZSTD_p_forceMaxWindow=1100, /* Force back-references to remain < windowSize,
|
||||
* even when referencing into Dictionary content
|
||||
* default : 0 when using a CDict, 1 when using a Prefix */
|
||||
} ZSTD_cParameter;
|
||||
|
||||
|
||||
/*! ZSTD_CCtx_setParameter() :
|
||||
* Set one compression parameter, selected by enum ZSTD_cParameter.
|
||||
* Note : when `value` is an enum, cast it to unsigned for proper type checking.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()). */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
|
||||
|
||||
/*! ZSTD_CCtx_setPledgedSrcSize() :
|
||||
* Total input data size to be compressed as a single frame.
|
||||
* This value will be controlled at the end, and result in error if not respected.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Note 1 : 0 means zero, empty.
|
||||
* In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
|
||||
* Note that ZSTD_CONTENTSIZE_UNKNOWN is default value for new compression jobs.
|
||||
* Note 2 : If all data is provided and consumed in a single round,
|
||||
* this value is overriden by srcSize instead. */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
|
||||
|
||||
/*! ZSTD_CCtx_loadDictionary() :
|
||||
* Create an internal CDict from dict buffer.
|
||||
* Decompression will have to use same buffer.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix,
|
||||
* meaning "return to no-dictionary mode".
|
||||
* Note 1 : Dictionary content will be copied internally,
|
||||
* except if ZSTD_p_refDictContent is set.
|
||||
* Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
|
||||
* For this reason, compression parameters cannot be changed anymore after loading a prefix.
|
||||
* It's also a CPU-heavy operation, with non-negligible impact on latency.
|
||||
* Note 3 : Dictionary will be used for all future compression jobs.
|
||||
* To return to "no-dictionary" situation, load a NULL dictionary */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
|
||||
|
||||
/*! ZSTD_CCtx_refCDict() :
|
||||
* Ref a prepared dictionary, to be used for all next compression jobs.
|
||||
* Note that compression parameters are enforced from within CDict,
|
||||
* and supercede any compression parameter previously set within CCtx.
|
||||
* The dictionary will remain valid for future compression jobs using same CCtx.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : adding a NULL CDict means "return to no-dictionary mode".
|
||||
* Note 1 : Currently, only one dictionary can be managed.
|
||||
* Adding a new dictionary effectively "discards" any previous one.
|
||||
* Note 2 : CDict is just referenced, its lifetime must outlive CCtx.
|
||||
*/
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
|
||||
|
||||
/*! ZSTD_CCtx_refPrefix() :
|
||||
* Reference a prefix (content-only dictionary) to bootstrap next compression job.
|
||||
* Decompression will have to use same prefix.
|
||||
* Prefix is only used once. Tables are discarded at end of compression job.
|
||||
* If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict.
|
||||
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
* Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix, meaning "return to no-dictionary mode".
|
||||
* Note 1 : Prefix buffer is referenced. It must outlive compression job.
|
||||
* Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
|
||||
* It's a CPU-heavy operation, with non-negligible impact on latency. */
|
||||
ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize); /* Not ready yet ! */
|
||||
|
||||
|
||||
|
||||
typedef enum {
|
||||
ZSTD_e_continue=0, /* collect more data, encoder transparently decides when to output result, for optimal conditions */
|
||||
ZSTD_e_flush, /* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */
|
||||
ZSTD_e_end /* flush any remaining data and ends current frame. Any future compression starts a new frame. */
|
||||
} ZSTD_EndDirective;
|
||||
|
||||
/*! ZSTD_compressStream_generic() :
|
||||
* Behave about the same as ZSTD_compressStream. To note :
|
||||
* - Compression parameters are pushed into CCtx before starting compression, using ZSTD_setCCtxParameter()
|
||||
* - Compression parameters cannot be changed once compression is started.
|
||||
* - *dstPos must be <= dstCapacity, *srcPos must be <= srcSize
|
||||
* - *dspPos and *srcPos will be updated. They are guaranteed to remain below their respective limit.
|
||||
* - @return provides the minimum amount of data still to flush from internal buffers
|
||||
* or an error code, which can be tested using ZSTD_isError().
|
||||
* if @return != 0, flush is not fully completed, and must be called again to empty internal buffers.
|
||||
* - after a ZSTD_e_end directive, if internal buffer is not fully flushed,
|
||||
* only ZSTD_e_end and ZSTD_e_flush operations are allowed.
|
||||
* It is necessary to fully flush internal buffers
|
||||
* before starting a new compression job, or changing compression parameters.
|
||||
*/
|
||||
ZSTDLIB_API size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
|
||||
ZSTD_outBuffer* output,
|
||||
ZSTD_inBuffer* input,
|
||||
ZSTD_EndDirective endOp);
|
||||
|
||||
/*! ZSTD_CCtx_reset() :
|
||||
* Return a CCtx to clean state.
|
||||
* Useful after an error, or to interrupt an ongoing compression job and start a new one.
|
||||
* Any internal data not yet flushed is cancelled.
|
||||
* Dictionary (if any) is dropped.
|
||||
* It's possible to modify compression parameters after a reset.
|
||||
*/
|
||||
ZSTDLIB_API void ZSTD_CCtx_reset(ZSTD_CCtx* cctx); /* Not ready yet ! */
|
||||
|
||||
|
||||
/*! ZSTD_compress_generic_simpleArgs() :
|
||||
* Same as ZSTD_compress_generic(),
|
||||
* but using only integral types as arguments.
|
||||
* Argument list is larger and less expressive than ZSTD_{in,out}Buffer,
|
||||
* but can be helpful for binders from dynamic languages
|
||||
* which have troubles handling structures containing memory pointers.
|
||||
*/
|
||||
size_t ZSTD_compress_generic_simpleArgs (
|
||||
ZSTD_CCtx* cctx,
|
||||
void* dst, size_t dstCapacity, size_t* dstPos,
|
||||
const void* src, size_t srcSize, size_t* srcPos,
|
||||
ZSTD_EndDirective endOp);
|
||||
|
||||
|
||||
/* note : this part if completely experimental, not ready yet.
|
||||
* Main idea is : if ZSTD_parameters is not a good fit for stable API,
|
||||
* there will be a need for something else.
|
||||
* While initialising compression is now correctly covered,
|
||||
* creating an advanced CDict still needs to be solved.
|
||||
* Below is merely a plan of what it could look like */
|
||||
/*! ZSTD_CDict_createEmpty() :
|
||||
* Create a CDict object which is still mutable after creation.
|
||||
* It's the only one case allowing usage of ZSTD_CDict_setParameter().
|
||||
* Once all compression parameters are selected,
|
||||
* it's possible to load the target dictionary, using ZSTD_CDict_loadDictionary().
|
||||
* Dictionary content will be copied internally (except if ZSTD_p_refDictContent is set).
|
||||
* After loading the dictionary, no more change is possible.
|
||||
* The only remaining operation is to free CDict object.
|
||||
* Note : An unfinished CDict behaves the same as a NULL CDict if referenced into a CCtx.
|
||||
*/
|
||||
ZSTDLIB_API ZSTD_CDict* ZSTD_CDict_createEmpty(void); /* Not ready yet ! */
|
||||
ZSTDLIB_API size_t ZSTD_CDict_setParameter(ZSTD_CDict* cdict, ZSTD_cParameter param, unsigned value); /* Not ready yet ! */
|
||||
ZSTDLIB_API size_t ZSTD_CDict_loadDictionary(ZSTD_CDict* cdict, const void* dict, size_t dictSize); /* Not ready yet ! */
|
||||
|
||||
|
||||
/**
|
||||
Block functions
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user