diff options
Diffstat (limited to 'lib/zstd.h')
| -rw-r--r-- | lib/zstd.h | 189 |
1 files changed, 129 insertions, 60 deletions
@@ -106,7 +106,7 @@ extern "C" { /*------ Version ------*/ #define ZSTD_VERSION_MAJOR 1 #define ZSTD_VERSION_MINOR 5 -#define ZSTD_VERSION_RELEASE 5 +#define ZSTD_VERSION_RELEASE 6 #define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE) /*! ZSTD_versionNumber() : @@ -228,7 +228,7 @@ ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize) * for example to size a static array on stack. * Will produce constant value 0 if srcSize too large. */ -#define ZSTD_MAX_INPUT_SIZE ((sizeof(size_t)==8) ? 0xFF00FF00FF00FF00LLU : 0xFF00FF00U) +#define ZSTD_MAX_INPUT_SIZE ((sizeof(size_t)==8) ? 0xFF00FF00FF00FF00ULL : 0xFF00FF00U) #define ZSTD_COMPRESSBOUND(srcSize) (((size_t)(srcSize) >= ZSTD_MAX_INPUT_SIZE) ? 0 : (srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0)) /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */ ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */ /* ZSTD_isError() : @@ -249,7 +249,7 @@ ZSTDLIB_API int ZSTD_defaultCLevel(void); /*!< default compres /*= Compression context * When compressing many times, * it is recommended to allocate a context just once, - * and re-use it for each successive compression operation. + * and reuse it for each successive compression operation. * This will make workload friendlier for system's memory. * Note : re-using context is just a speed / resource optimization. * It doesn't change the compression ratio, which remains identical. @@ -262,9 +262,9 @@ ZSTDLIB_API size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx); /* accept NULL pointer * /*! ZSTD_compressCCtx() : * Same as ZSTD_compress(), using an explicit ZSTD_CCtx. - * Important : in order to behave similarly to `ZSTD_compress()`, - * this function compresses at requested compression level, - * __ignoring any other parameter__ . + * Important : in order to mirror `ZSTD_compress()` behavior, + * this function compresses at the requested compression level, + * __ignoring any other advanced parameter__ . * If any advanced parameter was set using the advanced API, * they will all be reset. Only `compressionLevel` remains. */ @@ -276,7 +276,7 @@ ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx, /*= Decompression context * When decompressing many times, * it is recommended to allocate a context only once, - * and re-use it for each successive compression operation. + * and reuse it for each successive compression operation. * This will make workload friendlier for system's memory. * Use one context per thread for parallel execution. */ typedef struct ZSTD_DCtx_s ZSTD_DCtx; @@ -286,7 +286,7 @@ ZSTDLIB_API size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); /* accept NULL pointer * /*! ZSTD_decompressDCtx() : * Same as ZSTD_decompress(), * requires an allocated ZSTD_DCtx. - * Compatible with sticky parameters. + * Compatible with sticky parameters (see below). */ ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, @@ -302,12 +302,12 @@ ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, * using ZSTD_CCtx_set*() functions. * Pushed parameters are sticky : they are valid for next compressed frame, and any subsequent frame. * "sticky" parameters are applicable to `ZSTD_compress2()` and `ZSTD_compressStream*()` ! - * __They do not apply to "simple" one-shot variants such as ZSTD_compressCCtx()__ . + * __They do not apply to one-shot variants such as ZSTD_compressCCtx()__ . * * It's possible to reset all parameters to "default" using ZSTD_CCtx_reset(). * * This API supersedes all other "advanced" API entry points in the experimental section. - * In the future, we expect to remove from experimental API entry points which are redundant with this API. + * In the future, we expect to remove API entry points from experimental which are redundant with this API. */ @@ -390,6 +390,19 @@ typedef enum { * The higher the value of selected strategy, the more complex it is, * resulting in stronger and slower compression. * Special: value 0 means "use default strategy". */ + + ZSTD_c_targetCBlockSize=130, /* v1.5.6+ + * Attempts to fit compressed block size into approximatively targetCBlockSize. + * Bound by ZSTD_TARGETCBLOCKSIZE_MIN and ZSTD_TARGETCBLOCKSIZE_MAX. + * Note that it's not a guarantee, just a convergence target (default:0). + * No target when targetCBlockSize == 0. + * This is helpful in low bandwidth streaming environments to improve end-to-end latency, + * when a client can make use of partial documents (a prominent example being Chrome). + * Note: this parameter is stable since v1.5.6. + * It was present as an experimental parameter in earlier versions, + * but it's not recommended using it with earlier library versions + * due to massive performance regressions. + */ /* LDM mode parameters */ ZSTD_c_enableLongDistanceMatching=160, /* Enable long distance matching. * This parameter is designed to improve compression ratio @@ -469,7 +482,6 @@ typedef enum { * ZSTD_c_forceMaxWindow * ZSTD_c_forceAttachDict * ZSTD_c_literalCompressionMode - * ZSTD_c_targetCBlockSize * ZSTD_c_srcSizeHint * ZSTD_c_enableDedicatedDictSearch * ZSTD_c_stableInBuffer @@ -490,7 +502,7 @@ typedef enum { ZSTD_c_experimentalParam3=1000, ZSTD_c_experimentalParam4=1001, ZSTD_c_experimentalParam5=1002, - ZSTD_c_experimentalParam6=1003, + /* was ZSTD_c_experimentalParam6=1003; is now ZSTD_c_targetCBlockSize */ ZSTD_c_experimentalParam7=1004, ZSTD_c_experimentalParam8=1005, ZSTD_c_experimentalParam9=1006, @@ -575,6 +587,7 @@ ZSTDLIB_API size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset); /*! ZSTD_compress2() : * Behave the same as ZSTD_compressCCtx(), but compression parameters are set using the advanced API. + * (note that this entry point doesn't even expose a compression level parameter). * ZSTD_compress2() always starts a new frame. * Should cctx hold data from a previously unfinished frame, everything about it is forgotten. * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*() @@ -618,6 +631,7 @@ typedef enum { * ZSTD_d_forceIgnoreChecksum * ZSTD_d_refMultipleDDicts * ZSTD_d_disableHuffmanAssembly + * ZSTD_d_maxBlockSize * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them. * note : never ever use experimentalParam? names directly */ @@ -625,7 +639,8 @@ typedef enum { ZSTD_d_experimentalParam2=1001, ZSTD_d_experimentalParam3=1002, ZSTD_d_experimentalParam4=1003, - ZSTD_d_experimentalParam5=1004 + ZSTD_d_experimentalParam5=1004, + ZSTD_d_experimentalParam6=1005 } ZSTD_dParameter; @@ -680,14 +695,14 @@ typedef struct ZSTD_outBuffer_s { * A ZSTD_CStream object is required to track streaming operation. * Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources. * ZSTD_CStream objects can be reused multiple times on consecutive compression operations. -* It is recommended to re-use ZSTD_CStream since it will play nicer with system's memory, by re-using already allocated memory. +* It is recommended to reuse ZSTD_CStream since it will play nicer with system's memory, by re-using already allocated memory. * * For parallel execution, use one separate ZSTD_CStream per thread. * * note : since v1.3.0, ZSTD_CStream and ZSTD_CCtx are the same thing. * * Parameters are sticky : when starting a new compression on the same context, -* it will re-use the same sticky parameters as previous compression session. +* it will reuse the same sticky parameters as previous compression session. * When in doubt, it's recommended to fully initialize the context before usage. * Use ZSTD_CCtx_reset() to reset the context and ZSTD_CCtx_setParameter(), * ZSTD_CCtx_setPledgedSrcSize(), or ZSTD_CCtx_loadDictionary() and friends to @@ -776,6 +791,11 @@ typedef enum { * only ZSTD_e_end or ZSTD_e_flush operations are allowed. * Before starting a new compression job, or changing compression parameters, * it is required to fully flush internal buffers. + * - note: if an operation ends with an error, it may leave @cctx in an undefined state. + * Therefore, it's UB to invoke ZSTD_compressStream2() of ZSTD_compressStream() on such a state. + * In order to be re-employed after an error, a state must be reset, + * which can be done explicitly (ZSTD_CCtx_reset()), + * or is sometimes implied by methods starting a new compression job (ZSTD_initCStream(), ZSTD_compressCCtx()) */ ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx, ZSTD_outBuffer* output, @@ -835,7 +855,7 @@ ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output); * * A ZSTD_DStream object is required to track streaming operations. * Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources. -* ZSTD_DStream objects can be re-used multiple times. +* ZSTD_DStream objects can be reused multiple times. * * Use ZSTD_initDStream() to start a new decompression operation. * @return : recommended first input size @@ -889,6 +909,12 @@ ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds); * @return : 0 when a frame is completely decoded and fully flushed, * or an error code, which can be tested using ZSTD_isError(), * or any other value > 0, which means there is some decoding or flushing to do to complete current frame. + * + * Note: when an operation returns with an error code, the @zds state may be left in undefined state. + * It's UB to invoke `ZSTD_decompressStream()` on such a state. + * In order to re-use such a state, it must be first reset, + * which can be done explicitly (`ZSTD_DCtx_reset()`), + * or is implied for operations starting some new decompression job (`ZSTD_initDStream`, `ZSTD_decompressDCtx()`, `ZSTD_decompress_usingDict()`) */ ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input); @@ -1021,7 +1047,7 @@ ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize); * * This API allows dictionaries to be used with ZSTD_compress2(), * ZSTD_compressStream2(), and ZSTD_decompressDCtx(). - * Dictionaries are sticky, they remain valid when same context is re-used, + * Dictionaries are sticky, they remain valid when same context is reused, * they only reset when the context is reset * with ZSTD_reset_parameters or ZSTD_reset_session_and_parameters. * In contrast, Prefixes are single-use. @@ -1239,7 +1265,7 @@ ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); #define ZSTD_LDM_HASHRATELOG_MAX (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN) /* Advanced parameter bounds */ -#define ZSTD_TARGETCBLOCKSIZE_MIN 64 +#define ZSTD_TARGETCBLOCKSIZE_MIN 1340 /* suitable to fit into an ethernet / wifi / 4G transport frame */ #define ZSTD_TARGETCBLOCKSIZE_MAX ZSTD_BLOCKSIZE_MAX #define ZSTD_SRCSIZEHINT_MIN 0 #define ZSTD_SRCSIZEHINT_MAX INT_MAX @@ -1527,25 +1553,38 @@ typedef enum { ZSTDLIB_STATIC_API size_t ZSTD_sequenceBound(size_t srcSize); /*! ZSTD_generateSequences() : + * WARNING: This function is meant for debugging and informational purposes ONLY! + * Its implementation is flawed, and it will be deleted in a future version. + * It is not guaranteed to succeed, as there are several cases where it will give + * up and fail. You should NOT use this function in production code. + * + * This function is deprecated, and will be removed in a future version. + * * Generate sequences using ZSTD_compress2(), given a source buffer. * + * @param zc The compression context to be used for ZSTD_compress2(). Set any + * compression parameters you need on this context. + * @param outSeqs The output sequences buffer of size @p outSeqsSize + * @param outSeqsSize The size of the output sequences buffer. + * ZSTD_sequenceBound(srcSize) is an upper bound on the number + * of sequences that can be generated. + * @param src The source buffer to generate sequences from of size @p srcSize. + * @param srcSize The size of the 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(). - * - * 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 + * @returns The number of sequences generated, necessarily less than + * ZSTD_sequenceBound(srcSize), or an error code that can be checked + * with ZSTD_isError(). */ - +ZSTD_DEPRECATED("For debugging only, will be replaced by ZSTD_extractSequences()") ZSTDLIB_STATIC_API size_t -ZSTD_generateSequences( ZSTD_CCtx* zc, - ZSTD_Sequence* outSeqs, size_t outSeqsSize, - const void* src, size_t srcSize); +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 @@ -1640,56 +1679,59 @@ ZSTDLIB_API unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size); /*! ZSTD_estimate*() : * These functions make it possible to estimate memory usage * of a future {D,C}Ctx, before its creation. + * This is useful in combination with ZSTD_initStatic(), + * which makes it possible to employ a static buffer for ZSTD_CCtx* state. * * ZSTD_estimateCCtxSize() will provide a memory budget large enough - * for any compression level up to selected one. - * Note : Unlike ZSTD_estimateCStreamSize*(), this estimate - * does not include space for a window buffer. - * Therefore, the estimation is only guaranteed for single-shot compressions, not streaming. + * to compress data of any size using one-shot compression ZSTD_compressCCtx() or ZSTD_compress2() + * associated with any compression level up to max specified one. * The estimate will assume the input may be arbitrarily large, * which is the worst case. * + * Note that the size estimation is specific for one-shot compression, + * it is not valid for streaming (see ZSTD_estimateCStreamSize*()) + * nor other potential ways of using a ZSTD_CCtx* state. + * * When srcSize can be bound by a known and rather "small" value, - * this fact can be used to provide a tighter estimation - * because the CCtx compression context will need less memory. - * This tighter estimation can be provided by more advanced functions + * this knowledge can be used to provide a tighter budget estimation + * because the ZSTD_CCtx* state will need less memory for small inputs. + * This tighter estimation can be provided by employing more advanced functions * ZSTD_estimateCCtxSize_usingCParams(), which can be used in tandem with ZSTD_getCParams(), * and ZSTD_estimateCCtxSize_usingCCtxParams(), which can be used in tandem with ZSTD_CCtxParams_setParameter(). * Both can be used to estimate memory using custom compression parameters and arbitrary srcSize limits. * * Note : only single-threaded compression is supported. * ZSTD_estimateCCtxSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1. - * - * Note 2 : ZSTD_estimateCCtxSize* functions are not compatible with the Block-Level Sequence Producer API at this time. - * Size estimates assume that no external sequence producer is registered. */ -ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize(int compressionLevel); +ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize(int maxCompressionLevel); ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams); ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params); ZSTDLIB_STATIC_API size_t ZSTD_estimateDCtxSize(void); /*! ZSTD_estimateCStreamSize() : - * ZSTD_estimateCStreamSize() will provide a budget large enough for any compression level up to selected one. - * It will also consider src size to be arbitrarily "large", which is worst case. + * ZSTD_estimateCStreamSize() will provide a memory budget large enough for streaming compression + * using any compression level up to the max specified one. + * It will also consider src size to be arbitrarily "large", which is a worst case scenario. * If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation. * ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel. * ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParams_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1. * Note : CStream size estimation is only correct for single-threaded compression. - * ZSTD_DStream memory budget depends on window Size. + * ZSTD_estimateCStreamSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1. + * Note 2 : ZSTD_estimateCStreamSize* functions are not compatible with the Block-Level Sequence Producer API at this time. + * Size estimates assume that no external sequence producer is registered. + * + * ZSTD_DStream memory budget depends on frame's window Size. * This information can be passed manually, using ZSTD_estimateDStreamSize, * or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame(); + * Any frame requesting a window size larger than max specified one will be rejected. * Note : if streaming is init with function ZSTD_init?Stream_usingDict(), * an internal ?Dict will be created, which additional size is not estimated here. * In this case, get total size by adding ZSTD_estimate?DictSize - * Note 2 : only single-threaded compression is supported. - * ZSTD_estimateCStreamSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1. - * Note 3 : ZSTD_estimateCStreamSize* functions are not compatible with the Block-Level Sequence Producer API at this time. - * Size estimates assume that no external sequence producer is registered. */ -ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize(int compressionLevel); +ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize(int maxCompressionLevel); ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams); ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params); -ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize(size_t windowSize); +ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize(size_t maxWindowSize); ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize); /*! ZSTD_estimate?DictSize() : @@ -1946,11 +1988,6 @@ ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const vo */ #define ZSTD_c_literalCompressionMode ZSTD_c_experimentalParam5 -/* Tries to fit compressed block size to be around targetCBlockSize. - * No target when targetCBlockSize == 0. - * There is no guarantee on compressed block size (default:0) */ -#define ZSTD_c_targetCBlockSize ZSTD_c_experimentalParam6 - /* User's best guess of source size. * Hint is not valid when srcSizeHint == 0. * There is no guarantee that hint is close to actual source size, @@ -2430,6 +2467,22 @@ ZSTDLIB_STATIC_API size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParamete */ #define ZSTD_d_disableHuffmanAssembly ZSTD_d_experimentalParam5 +/* ZSTD_d_maxBlockSize + * Allowed values are between 1KB and ZSTD_BLOCKSIZE_MAX (128KB). + * The default is ZSTD_BLOCKSIZE_MAX, and setting to 0 will set to the default. + * + * Forces the decompressor to reject blocks whose content size is + * larger than the configured maxBlockSize. When maxBlockSize is + * larger than the windowSize, the windowSize is used instead. + * This saves memory on the decoder when you know all blocks are small. + * + * This option is typically used in conjunction with ZSTD_c_maxBlockSize. + * + * WARNING: This causes the decoder to reject otherwise valid frames + * that have block sizes larger than the configured maxBlockSize. + */ +#define ZSTD_d_maxBlockSize ZSTD_d_experimentalParam6 + /*! ZSTD_DCtx_setFormat() : * This function is REDUNDANT. Prefer ZSTD_DCtx_setParameter(). @@ -2557,7 +2610,7 @@ size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, * explicitly specified. * * start a new frame, using same parameters from previous frame. - * This is typically useful to skip dictionary loading stage, since it will re-use it in-place. + * This is typically useful to skip dictionary loading stage, since it will reuse it in-place. * Note that zcs must be init at least once before using ZSTD_resetCStream(). * If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN. * If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end. @@ -2633,7 +2686,7 @@ ZSTDLIB_STATIC_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const Z * * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only); * - * re-use decompression parameters from previous init; saves dictionary loading + * reuse decompression parameters from previous init; saves dictionary loading */ ZSTD_DEPRECATED("use ZSTD_DCtx_reset, see zstd.h for detailed instructions") ZSTDLIB_STATIC_API size_t ZSTD_resetDStream(ZSTD_DStream* zds); @@ -2765,7 +2818,7 @@ ZSTDLIB_STATIC_API size_t ZSTD_resetDStream(ZSTD_DStream* zds); #define ZSTD_SEQUENCE_PRODUCER_ERROR ((size_t)(-1)) -typedef size_t ZSTD_sequenceProducer_F ( +typedef size_t (*ZSTD_sequenceProducer_F) ( void* sequenceProducerState, ZSTD_Sequence* outSeqs, size_t outSeqsCapacity, const void* src, size_t srcSize, @@ -2797,7 +2850,23 @@ ZSTDLIB_STATIC_API void ZSTD_registerSequenceProducer( ZSTD_CCtx* cctx, void* sequenceProducerState, - ZSTD_sequenceProducer_F* sequenceProducer + ZSTD_sequenceProducer_F sequenceProducer +); + +/*! ZSTD_CCtxParams_registerSequenceProducer() : + * Same as ZSTD_registerSequenceProducer(), but operates on ZSTD_CCtx_params. + * This is used for accurate size estimation with ZSTD_estimateCCtxSize_usingCCtxParams(), + * which is needed when creating a ZSTD_CCtx with ZSTD_initStaticCCtx(). + * + * If you are using the external sequence producer API in a scenario where ZSTD_initStaticCCtx() + * is required, then this function is for you. Otherwise, you probably don't need it. + * + * See tests/zstreamtest.c for example usage. */ +ZSTDLIB_STATIC_API void +ZSTD_CCtxParams_registerSequenceProducer( + ZSTD_CCtx_params* params, + void* sequenceProducerState, + ZSTD_sequenceProducer_F sequenceProducer ); @@ -2820,7 +2889,7 @@ ZSTD_registerSequenceProducer( A ZSTD_CCtx object is required to track streaming operations. Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource. - ZSTD_CCtx object can be re-used multiple times within successive compression operations. + ZSTD_CCtx object can be reused multiple times within successive compression operations. Start by initializing a context. Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression. @@ -2841,7 +2910,7 @@ ZSTD_registerSequenceProducer( It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame. Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders. - `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress again. + `ZSTD_CCtx` object can be reused (ZSTD_compressBegin()) to compress again. */ /*===== Buffer-less streaming compression functions =====*/ @@ -2873,7 +2942,7 @@ size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_ A ZSTD_DCtx object is required to track streaming operations. Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it. - A ZSTD_DCtx object can be re-used multiple times. + A ZSTD_DCtx object can be reused multiple times. First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader(). Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough. |