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authorRémi Verschelde <rverschelde@gmail.com>2019-04-18 11:53:29 +0200
committerRémi Verschelde <rverschelde@gmail.com>2019-04-18 12:39:11 +0200
commit88cb9bd27f05f6622b4c8205d2811e4aad74d6e3 (patch)
tree12faaaa31169709cecf0daea0d63fa122592c09a /thirdparty/zstd/zstd.h
parent6697fd9a05859914fc320b4b4321fd9fb6170f71 (diff)
zstd: Update to upstream 1.4.0
One step towards fixing #17374 as most experimental APIs we use are now part of the stable 1.4.0.
Diffstat (limited to 'thirdparty/zstd/zstd.h')
-rw-r--r--thirdparty/zstd/zstd.h1021
1 files changed, 584 insertions, 437 deletions
diff --git a/thirdparty/zstd/zstd.h b/thirdparty/zstd/zstd.h
index b18fc8a44b..53470c18f3 100644
--- a/thirdparty/zstd/zstd.h
+++ b/thirdparty/zstd/zstd.h
@@ -70,8 +70,8 @@ extern "C" {
/*------ Version ------*/
#define ZSTD_VERSION_MAJOR 1
-#define ZSTD_VERSION_MINOR 3
-#define ZSTD_VERSION_RELEASE 8
+#define ZSTD_VERSION_MINOR 4
+#define ZSTD_VERSION_RELEASE 0
#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< to check runtime library version */
@@ -90,6 +90,21 @@ ZSTDLIB_API const char* ZSTD_versionString(void); /* requires v1.3.0+ */
#endif
/***************************************
+* Constants
+***************************************/
+
+/* All magic numbers are supposed read/written to/from files/memory using little-endian convention */
+#define ZSTD_MAGICNUMBER 0xFD2FB528 /* valid since v0.8.0 */
+#define ZSTD_MAGIC_DICTIONARY 0xEC30A437 /* valid since v0.7.0 */
+#define ZSTD_MAGIC_SKIPPABLE_START 0x184D2A50 /* all 16 values, from 0x184D2A50 to 0x184D2A5F, signal the beginning of a skippable frame */
+#define ZSTD_MAGIC_SKIPPABLE_MASK 0xFFFFFFF0
+
+#define ZSTD_BLOCKSIZELOG_MAX 17
+#define ZSTD_BLOCKSIZE_MAX (1<<ZSTD_BLOCKSIZELOG_MAX)
+
+
+
+/***************************************
* Simple API
***************************************/
/*! ZSTD_compress() :
@@ -145,12 +160,21 @@ ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t
* @return : decompressed size of `src` frame content _if known and not empty_, 0 otherwise. */
ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
+/*! ZSTD_findFrameCompressedSize() :
+ * `src` should point to the start of a ZSTD frame or skippable frame.
+ * `srcSize` must be >= first frame size
+ * @return : the compressed size of the first frame starting at `src`,
+ * suitable to pass as `srcSize` to `ZSTD_decompress` or similar,
+ * or an error code if input is invalid */
+ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
+
/*====== Helper functions ======*/
#define ZSTD_COMPRESSBOUND(srcSize) ((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 */
ZSTDLIB_API unsigned ZSTD_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
ZSTDLIB_API const char* ZSTD_getErrorName(size_t code); /*!< provides readable string from an error code */
+ZSTDLIB_API int ZSTD_minCLevel(void); /*!< minimum negative compression level allowed */
ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
@@ -195,279 +219,6 @@ ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx,
const void* src, size_t srcSize);
-/**************************
-* Simple dictionary API
-***************************/
-/*! ZSTD_compress_usingDict() :
- * Compression at an explicit compression level using a Dictionary.
- * A dictionary can be any arbitrary data segment (also called a prefix),
- * or a buffer with specified information (see dictBuilder/zdict.h).
- * Note : This function loads the dictionary, resulting in significant startup delay.
- * It's intended for a dictionary used only once.
- * Note 2 : When `dict == NULL || dictSize < 8` no dictionary is used. */
-ZSTDLIB_API size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const void* dict,size_t dictSize,
- int compressionLevel);
-
-/*! ZSTD_decompress_usingDict() :
- * Decompression using a known Dictionary.
- * Dictionary must be identical to the one used during compression.
- * Note : This function loads the dictionary, resulting in significant startup delay.
- * It's intended for a dictionary used only once.
- * Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
-ZSTDLIB_API size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const void* dict,size_t dictSize);
-
-
-/***********************************
- * Bulk processing dictionary API
- **********************************/
-typedef struct ZSTD_CDict_s ZSTD_CDict;
-
-/*! ZSTD_createCDict() :
- * When compressing multiple messages / blocks using the same dictionary, it's recommended to load it only once.
- * ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup cost.
- * ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
- * `dictBuffer` can be released after ZSTD_CDict creation, because its content is copied within CDict.
- * Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate `dictBuffer` content.
- * Note : A ZSTD_CDict can be created from an empty dictBuffer, but it is inefficient when used to compress small data. */
-ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
- int compressionLevel);
-
-/*! ZSTD_freeCDict() :
- * Function frees memory allocated by ZSTD_createCDict(). */
-ZSTDLIB_API size_t ZSTD_freeCDict(ZSTD_CDict* CDict);
-
-/*! ZSTD_compress_usingCDict() :
- * Compression using a digested Dictionary.
- * Recommended when same dictionary is used multiple times.
- * Note : compression level is _decided at dictionary creation time_,
- * and frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) */
-ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const ZSTD_CDict* cdict);
-
-
-typedef struct ZSTD_DDict_s ZSTD_DDict;
-
-/*! ZSTD_createDDict() :
- * Create a digested dictionary, ready to start decompression operation without startup delay.
- * dictBuffer can be released after DDict creation, as its content is copied inside DDict. */
-ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
-
-/*! ZSTD_freeDDict() :
- * Function frees memory allocated with ZSTD_createDDict() */
-ZSTDLIB_API size_t ZSTD_freeDDict(ZSTD_DDict* ddict);
-
-/*! ZSTD_decompress_usingDDict() :
- * Decompression using a digested Dictionary.
- * Recommended when same dictionary is used multiple times. */
-ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const ZSTD_DDict* ddict);
-
-
-/****************************
-* Streaming
-****************************/
-
-typedef struct ZSTD_inBuffer_s {
- const void* src; /**< start of input buffer */
- size_t size; /**< size of input buffer */
- size_t pos; /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
-} ZSTD_inBuffer;
-
-typedef struct ZSTD_outBuffer_s {
- void* dst; /**< start of output buffer */
- size_t size; /**< size of output buffer */
- size_t pos; /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
-} ZSTD_outBuffer;
-
-
-
-/*-***********************************************************************
-* Streaming compression - HowTo
-*
-* 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.
-*
-* 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.
-* When in doubt, it's recommended to fully initialize the context before usage.
-* Use ZSTD_initCStream() to set the parameter to a selected compression level.
-* Use advanced API (ZSTD_CCtx_setParameter(), etc.) to set more specific parameters.
-*
-* Use ZSTD_compressStream() as many times as necessary to consume input stream.
-* The function will automatically update both `pos` fields within `input` and `output`.
-* Note that the function may not consume the entire input,
-* for example, because the output buffer is already full,
-* in which case `input.pos < input.size`.
-* The caller must check if input has been entirely consumed.
-* If not, the caller must make some room to receive more compressed data,
-* and then present again remaining input data.
-* @return : a size hint, preferred nb of bytes to use as input for next function call
-* or an error code, which can be tested using ZSTD_isError().
-* Note 1 : it's just a hint, to help latency a little, any value will work fine.
-* Note 2 : size hint is guaranteed to be <= ZSTD_CStreamInSize()
-*
-* At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
-* using ZSTD_flushStream(). `output->pos` will be updated.
-* Note that, if `output->size` is too small, a single invocation of ZSTD_flushStream() might not be enough (return code > 0).
-* In which case, make some room to receive more compressed data, and call again ZSTD_flushStream().
-* @return : 0 if internal buffers are entirely flushed,
-* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
-* or an error code, which can be tested using ZSTD_isError().
-*
-* ZSTD_endStream() instructs to finish a frame.
-* It will perform a flush and write frame epilogue.
-* The epilogue is required for decoders to consider a frame completed.
-* flush() operation is the same, and follows same rules as ZSTD_flushStream().
-* @return : 0 if frame fully completed and fully flushed,
-* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
-* or an error code, which can be tested using ZSTD_isError().
-*
-* *******************************************************************/
-
-typedef ZSTD_CCtx ZSTD_CStream; /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
- /* Continue to distinguish them for compatibility with older versions <= v1.2.0 */
-/*===== ZSTD_CStream management functions =====*/
-ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
-ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
-
-/*===== Streaming compression functions =====*/
-ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
-ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
-ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
-ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
-
-ZSTDLIB_API size_t ZSTD_CStreamInSize(void); /**< recommended size for input buffer */
-ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
-
-
-
-/*-***************************************************************************
-* Streaming decompression - HowTo
-*
-* 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.
-*
-* Use ZSTD_initDStream() to start a new decompression operation.
-* @return : recommended first input size
-* Alternatively, use advanced API to set specific properties.
-*
-* Use ZSTD_decompressStream() repetitively to consume your input.
-* The function will update both `pos` fields.
-* If `input.pos < input.size`, some input has not been consumed.
-* It's up to the caller to present again remaining data.
-* The function tries to flush all data decoded immediately, respecting output buffer size.
-* If `output.pos < output.size`, decoder has flushed everything it could.
-* But if `output.pos == output.size`, there might be some data left within internal buffers.,
-* In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
-* Note : with no additional input provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
-* @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 still some decoding or flushing to do to complete current frame :
-* the return value is a suggested next input size (just a hint for better latency)
-* that will never request more than the remaining frame size.
-* *******************************************************************************/
-
-typedef ZSTD_DCtx ZSTD_DStream; /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
- /* For compatibility with versions <= v1.2.0, prefer differentiating them. */
-/*===== ZSTD_DStream management functions =====*/
-ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
-ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
-
-/*===== Streaming decompression functions =====*/
-ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);
-ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
-
-ZSTDLIB_API size_t ZSTD_DStreamInSize(void); /*!< recommended size for input buffer */
-ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
-
-#endif /* ZSTD_H_235446 */
-
-
-
-
-/****************************************************************************************
- * ADVANCED AND EXPERIMENTAL FUNCTIONS
- ****************************************************************************************
- * The definitions in the following section are considered experimental.
- * They are provided for advanced scenarios.
- * They should never be used with a dynamic library, as prototypes may change in the future.
- * Use them only in association with static linking.
- * ***************************************************************************************/
-
-#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
-#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
-
-
-/****************************************************************************************
- * Candidate API for promotion to stable status
- ****************************************************************************************
- * The following symbols and constants form the "staging area" :
- * they are considered to join "stable API" by v1.4.0.
- * The proposal is written so that it can be made stable "as is",
- * though it's still possible to suggest improvements.
- * Staging is in fact last chance for changes,
- * the API is locked once reaching "stable" status.
- * ***************************************************************************************/
-
-
-/* === Constants === */
-
-/* all magic numbers are supposed read/written to/from files/memory using little-endian convention */
-#define ZSTD_MAGICNUMBER 0xFD2FB528 /* valid since v0.8.0 */
-#define ZSTD_MAGIC_DICTIONARY 0xEC30A437 /* valid since v0.7.0 */
-#define ZSTD_MAGIC_SKIPPABLE_START 0x184D2A50 /* all 16 values, from 0x184D2A50 to 0x184D2A5F, signal the beginning of a skippable frame */
-#define ZSTD_MAGIC_SKIPPABLE_MASK 0xFFFFFFF0
-
-#define ZSTD_BLOCKSIZELOG_MAX 17
-#define ZSTD_BLOCKSIZE_MAX (1<<ZSTD_BLOCKSIZELOG_MAX)
-
-
-/* === query limits === */
-
-ZSTDLIB_API int ZSTD_minCLevel(void); /*!< minimum negative compression level allowed */
-
-
-/* === frame size === */
-
-/*! ZSTD_findFrameCompressedSize() :
- * `src` should point to the start of a ZSTD frame or skippable frame.
- * `srcSize` must be >= first frame size
- * @return : the compressed size of the first frame starting at `src`,
- * suitable to pass as `srcSize` to `ZSTD_decompress` or similar,
- * or an error code if input is invalid */
-ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
-
-
-/* === Memory management === */
-
-/*! ZSTD_sizeof_*() :
- * These functions give the _current_ memory usage of selected object.
- * Note that object memory usage can evolve (increase or decrease) over time. */
-ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
-ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
-ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
-ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
-ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
-ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
-
-
/***************************************
* Advanced compression API
***************************************/
@@ -503,7 +254,10 @@ typedef enum { ZSTD_fast=1,
typedef enum {
- /* compression parameters */
+ /* compression parameters
+ * Note: When compressing with a ZSTD_CDict these parameters are superseded
+ * by the parameters used to construct the ZSTD_CDict. See ZSTD_CCtx_refCDict()
+ * for more info (superseded-by-cdict). */
ZSTD_c_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
* Default level is ZSTD_CLEVEL_DEFAULT==3.
* Special: value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
@@ -625,6 +379,7 @@ typedef enum {
* ZSTD_c_format
* ZSTD_c_forceMaxWindow
* ZSTD_c_forceAttachDict
+ * ZSTD_c_literalCompressionMode
* Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
* note : never ever use experimentalParam? names directly;
* also, the enums values themselves are unstable and can still change.
@@ -632,10 +387,10 @@ typedef enum {
ZSTD_c_experimentalParam1=500,
ZSTD_c_experimentalParam2=10,
ZSTD_c_experimentalParam3=1000,
- ZSTD_c_experimentalParam4=1001
+ ZSTD_c_experimentalParam4=1001,
+ ZSTD_c_experimentalParam5=1002,
} ZSTD_cParameter;
-
typedef struct {
size_t error;
int lowerBound;
@@ -677,63 +432,10 @@ ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param
* Note 3 : Whenever all input data is provided and consumed in a single round,
* for example with ZSTD_compress2(),
* or invoking immediately ZSTD_compressStream2(,,,ZSTD_e_end),
- * this value is automatically overriden by srcSize instead.
+ * this value is automatically overridden 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 dictionary.
- * @result : 0, or an error code (which can be tested with ZSTD_isError()).
- * Special: Loading a NULL (or 0-size) dictionary invalidates previous dictionary,
- * meaning "return to no-dictionary mode".
- * Note 1 : Dictionary is sticky, it will be used for all future compressed frames.
- * To return to "no-dictionary" situation, load a NULL dictionary (or reset parameters).
- * Note 2 : Loading a dictionary involves building tables.
- * It's also a CPU consuming operation, with non-negligible impact on latency.
- * Tables are dependent on compression parameters, and for this reason,
- * compression parameters can no longer be changed after loading a dictionary.
- * Note 3 :`dict` content will be copied internally.
- * Use experimental ZSTD_CCtx_loadDictionary_byReference() to reference content instead.
- * In such a case, dictionary buffer must outlive its users.
- * Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
- * to precisely select how dictionary content must be interpreted. */
-ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
-
-/*! ZSTD_CCtx_refCDict() :
- * Reference a prepared dictionary, to be used for all next compressed frames.
- * 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 compressed frames using same CCtx.
- * @result : 0, or an error code (which can be tested with ZSTD_isError()).
- * Special : Referencing a NULL CDict means "return to no-dictionary mode".
- * Note 1 : Currently, only one dictionary can be managed.
- * Referencing a new dictionary effectively "discards" any previous one.
- * Note 2 : CDict is just referenced, its lifetime must outlive its usage within CCtx. */
-ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
-
-/*! ZSTD_CCtx_refPrefix() :
- * Reference a prefix (single-usage dictionary) for next compressed frame.
- * A prefix is **only used once**. Tables are discarded at end of frame (ZSTD_e_end).
- * Decompression will need same prefix to properly regenerate data.
- * Compressing with a prefix is similar in outcome as performing a diff and compressing it,
- * but performs much faster, especially during decompression (compression speed is tunable with compression level).
- * @result : 0, or an error code (which can be tested with ZSTD_isError()).
- * Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
- * Note 1 : Prefix buffer is referenced. It **must** outlive compression.
- * Its content must remain unmodified during compression.
- * Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
- * ensure that the window size is large enough to contain the entire source.
- * See ZSTD_c_windowLog.
- * Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
- * It's a CPU consuming operation, with non-negligible impact on latency.
- * If there is a need to use the same prefix multiple times, consider loadDictionary instead.
- * Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dm_rawContent).
- * Use experimental ZSTD_CCtx_refPrefix_advanced() to alter dictionary interpretation. */
-ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
- const void* prefix, size_t prefixSize);
-
-
typedef enum {
ZSTD_reset_session_only = 1,
ZSTD_reset_parameters = 2,
@@ -756,8 +458,6 @@ typedef enum {
*/
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.
* ZSTD_compress2() always starts a new frame.
@@ -772,48 +472,10 @@ ZSTDLIB_API size_t ZSTD_compress2( ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize);
-typedef enum {
- ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
- ZSTD_e_flush=1, /* flush any data provided so far,
- * it creates (at least) one new block, that can be decoded immediately on reception;
- * frame will continue: any future data can still reference previously compressed data, improving compression. */
- ZSTD_e_end=2 /* flush any remaining data _and_ close current frame.
- * note that frame is only closed after compressed data is fully flushed (return value == 0).
- * After that point, any additional data starts a new frame.
- * note : each frame is independent (does not reference any content from previous frame). */
-} ZSTD_EndDirective;
-
-/*! ZSTD_compressStream2() :
- * Behaves about the same as ZSTD_compressStream, with additional control on end directive.
- * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
- * - Compression parameters cannot be changed once compression is started (save a list of exceptions in multi-threading mode)
- * - outpot->pos must be <= dstCapacity, input->pos must be <= srcSize
- * - outpot->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
- * - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
- * - When nbWorkers>=1, function is non-blocking : it just acquires a copy of input, and distributes jobs to internal worker threads, flush whatever is available,
- * and then immediately returns, just indicating that there is some data remaining to be flushed.
- * The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
- * - Exception : if the first call requests a ZSTD_e_end directive and provides enough dstCapacity, the function delegates to ZSTD_compress2() which is always blocking.
- * - @return provides a minimum amount of data remaining to be flushed from internal buffers
- * or an error code, which can be tested using ZSTD_isError().
- * if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
- * This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
- * For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
- * - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
- * 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.
- */
-ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
- ZSTD_outBuffer* output,
- ZSTD_inBuffer* input,
- ZSTD_EndDirective endOp);
-
-
-/* ============================== */
-/* Advanced decompression API */
-/* ============================== */
+/***************************************
+* Advanced decompression API
+***************************************/
/* The advanced API pushes parameters one by one into an existing DCtx context.
* Parameters are sticky, and remain valid for all following frames
@@ -823,14 +485,14 @@ ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
* Therefore, no new decompression function is necessary.
*/
-
typedef enum {
ZSTD_d_windowLogMax=100, /* Select a size limit (in power of 2) beyond which
* the streaming API will refuse to allocate memory buffer
* in order to protect the host from unreasonable memory requirements.
* This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
- * By default, a decompression context accepts window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) */
+ * By default, a decompression context accepts window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT).
+ * Special: value 0 means "use default maximum windowLog". */
/* note : additional experimental parameters are also available
* within the experimental section of the API.
@@ -843,7 +505,6 @@ typedef enum {
} ZSTD_dParameter;
-
/*! ZSTD_dParam_getBounds() :
* All parameters must belong to an interval with lower and upper bounds,
* otherwise they will either trigger an error or be automatically clamped.
@@ -862,6 +523,389 @@ ZSTDLIB_API ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam);
*/
ZSTDLIB_API size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int value);
+/*! ZSTD_DCtx_reset() :
+ * Return a DCtx to clean state.
+ * Session and parameters can be reset jointly or separately.
+ * Parameters can only be reset when no active frame is being decompressed.
+ * @return : 0, or an error code, which can be tested with ZSTD_isError()
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);
+
+
+/****************************
+* Streaming
+****************************/
+
+typedef struct ZSTD_inBuffer_s {
+ const void* src; /**< start of input buffer */
+ size_t size; /**< size of input buffer */
+ size_t pos; /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
+} ZSTD_inBuffer;
+
+typedef struct ZSTD_outBuffer_s {
+ void* dst; /**< start of output buffer */
+ size_t size; /**< size of output buffer */
+ size_t pos; /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
+} ZSTD_outBuffer;
+
+
+
+/*-***********************************************************************
+* Streaming compression - HowTo
+*
+* 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.
+*
+* 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.
+* 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
+* set more specific parameters, the pledged source size, or load a dictionary.
+*
+* Use ZSTD_compressStream2() with ZSTD_e_continue as many times as necessary to
+* consume input stream. The function will automatically update both `pos`
+* fields within `input` and `output`.
+* Note that the function may not consume the entire input, for example, because
+* the output buffer is already full, in which case `input.pos < input.size`.
+* The caller must check if input has been entirely consumed.
+* If not, the caller must make some room to receive more compressed data,
+* and then present again remaining input data.
+* note: ZSTD_e_continue is guaranteed to make some forward progress when called,
+* but doesn't guarantee maximal forward progress. This is especially relevant
+* when compressing with multiple threads. The call won't block if it can
+* consume some input, but if it can't it will wait for some, but not all,
+* output to be flushed.
+* @return : provides a minimum amount of data remaining to be flushed from internal buffers
+* or an error code, which can be tested using ZSTD_isError().
+*
+* At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
+* using ZSTD_compressStream2() with ZSTD_e_flush. `output->pos` will be updated.
+* Note that, if `output->size` is too small, a single invocation with ZSTD_e_flush might not be enough (return code > 0).
+* In which case, make some room to receive more compressed data, and call again ZSTD_compressStream2() with ZSTD_e_flush.
+* You must continue calling ZSTD_compressStream2() with ZSTD_e_flush until it returns 0, at which point you can change the
+* operation.
+* note: ZSTD_e_flush will flush as much output as possible, meaning when compressing with multiple threads, it will
+* block until the flush is complete or the output buffer is full.
+* @return : 0 if internal buffers are entirely flushed,
+* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
+* or an error code, which can be tested using ZSTD_isError().
+*
+* Calling ZSTD_compressStream2() with ZSTD_e_end instructs to finish a frame.
+* It will perform a flush and write frame epilogue.
+* The epilogue is required for decoders to consider a frame completed.
+* flush operation is the same, and follows same rules as calling ZSTD_compressStream2() with ZSTD_e_flush.
+* You must continue calling ZSTD_compressStream2() with ZSTD_e_end until it returns 0, at which point you are free to
+* start a new frame.
+* note: ZSTD_e_end will flush as much output as possible, meaning when compressing with multiple threads, it will
+* block until the flush is complete or the output buffer is full.
+* @return : 0 if frame fully completed and fully flushed,
+* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
+* or an error code, which can be tested using ZSTD_isError().
+*
+* *******************************************************************/
+
+typedef ZSTD_CCtx ZSTD_CStream; /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
+ /* Continue to distinguish them for compatibility with older versions <= v1.2.0 */
+/*===== ZSTD_CStream management functions =====*/
+ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
+ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
+
+/*===== Streaming compression functions =====*/
+typedef enum {
+ ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
+ ZSTD_e_flush=1, /* flush any data provided so far,
+ * it creates (at least) one new block, that can be decoded immediately on reception;
+ * frame will continue: any future data can still reference previously compressed data, improving compression.
+ * note : multithreaded compression will block to flush as much output as possible. */
+ ZSTD_e_end=2 /* flush any remaining data _and_ close current frame.
+ * note that frame is only closed after compressed data is fully flushed (return value == 0).
+ * After that point, any additional data starts a new frame.
+ * note : each frame is independent (does not reference any content from previous frame).
+ : note : multithreaded compression will block to flush as much output as possible. */
+} ZSTD_EndDirective;
+
+/*! ZSTD_compressStream2() :
+ * Behaves about the same as ZSTD_compressStream, with additional control on end directive.
+ * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
+ * - Compression parameters cannot be changed once compression is started (save a list of exceptions in multi-threading mode)
+ * - output->pos must be <= dstCapacity, input->pos must be <= srcSize
+ * - output->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
+ * - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
+ * - When nbWorkers>=1, function is non-blocking : it just acquires a copy of input, and distributes jobs to internal worker threads, flush whatever is available,
+ * and then immediately returns, just indicating that there is some data remaining to be flushed.
+ * The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
+ * - Exception : if the first call requests a ZSTD_e_end directive and provides enough dstCapacity, the function delegates to ZSTD_compress2() which is always blocking.
+ * - @return provides a minimum amount of data remaining to be flushed from internal buffers
+ * or an error code, which can be tested using ZSTD_isError().
+ * if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
+ * This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
+ * For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
+ * - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
+ * 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.
+ */
+ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
+ ZSTD_outBuffer* output,
+ ZSTD_inBuffer* input,
+ ZSTD_EndDirective endOp);
+
+ZSTDLIB_API size_t ZSTD_CStreamInSize(void); /**< recommended size for input buffer */
+ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
+
+/*******************************************************************************
+ * This is a legacy streaming API, and can be replaced by ZSTD_CCtx_reset() and
+ * ZSTD_compressStream2(). It is redundant, but is still fully supported.
+ * Advanced parameters and dictionary compression can only be used through the
+ * new API.
+ ******************************************************************************/
+
+/**
+ * Equivalent to:
+ *
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ */
+ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
+/**
+ * Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).
+ * NOTE: The return value is different. ZSTD_compressStream() returns a hint for
+ * the next read size (if non-zero and not an error). ZSTD_compressStream2()
+ * returns the number of bytes left to flush (if non-zero and not an error).
+ */
+ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
+/** Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush). */
+ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+/** Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end). */
+ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+
+
+/*-***************************************************************************
+* Streaming decompression - HowTo
+*
+* 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.
+*
+* Use ZSTD_initDStream() to start a new decompression operation.
+* @return : recommended first input size
+* Alternatively, use advanced API to set specific properties.
+*
+* Use ZSTD_decompressStream() repetitively to consume your input.
+* The function will update both `pos` fields.
+* If `input.pos < input.size`, some input has not been consumed.
+* It's up to the caller to present again remaining data.
+* The function tries to flush all data decoded immediately, respecting output buffer size.
+* If `output.pos < output.size`, decoder has flushed everything it could.
+* But if `output.pos == output.size`, there might be some data left within internal buffers.,
+* In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
+* Note : with no additional input provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
+* @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 still some decoding or flushing to do to complete current frame :
+* the return value is a suggested next input size (just a hint for better latency)
+* that will never request more than the remaining frame size.
+* *******************************************************************************/
+
+typedef ZSTD_DCtx ZSTD_DStream; /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
+ /* For compatibility with versions <= v1.2.0, prefer differentiating them. */
+/*===== ZSTD_DStream management functions =====*/
+ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
+ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
+
+/*===== Streaming decompression functions =====*/
+
+/* This function is redundant with the advanced API and equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds);
+ * ZSTD_DCtx_refDDict(zds, NULL);
+ */
+ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);
+
+ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
+
+ZSTDLIB_API size_t ZSTD_DStreamInSize(void); /*!< recommended size for input buffer */
+ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
+
+
+/**************************
+* Simple dictionary API
+***************************/
+/*! ZSTD_compress_usingDict() :
+ * Compression at an explicit compression level using a Dictionary.
+ * A dictionary can be any arbitrary data segment (also called a prefix),
+ * or a buffer with specified information (see dictBuilder/zdict.h).
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * It's intended for a dictionary used only once.
+ * Note 2 : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ZSTDLIB_API size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize,
+ int compressionLevel);
+
+/*! ZSTD_decompress_usingDict() :
+ * Decompression using a known Dictionary.
+ * Dictionary must be identical to the one used during compression.
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * It's intended for a dictionary used only once.
+ * Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ZSTDLIB_API size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize);
+
+
+/***********************************
+ * Bulk processing dictionary API
+ **********************************/
+typedef struct ZSTD_CDict_s ZSTD_CDict;
+
+/*! ZSTD_createCDict() :
+ * When compressing multiple messages / blocks using the same dictionary, it's recommended to load it only once.
+ * ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup cost.
+ * ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * `dictBuffer` can be released after ZSTD_CDict creation, because its content is copied within CDict.
+ * Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate `dictBuffer` content.
+ * Note : A ZSTD_CDict can be created from an empty dictBuffer, but it is inefficient when used to compress small data. */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
+ int compressionLevel);
+
+/*! ZSTD_freeCDict() :
+ * Function frees memory allocated by ZSTD_createCDict(). */
+ZSTDLIB_API size_t ZSTD_freeCDict(ZSTD_CDict* CDict);
+
+/*! ZSTD_compress_usingCDict() :
+ * Compression using a digested Dictionary.
+ * Recommended when same dictionary is used multiple times.
+ * Note : compression level is _decided at dictionary creation time_,
+ * and frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) */
+ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_CDict* cdict);
+
+
+typedef struct ZSTD_DDict_s ZSTD_DDict;
+
+/*! ZSTD_createDDict() :
+ * Create a digested dictionary, ready to start decompression operation without startup delay.
+ * dictBuffer can be released after DDict creation, as its content is copied inside DDict. */
+ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
+
+/*! ZSTD_freeDDict() :
+ * Function frees memory allocated with ZSTD_createDDict() */
+ZSTDLIB_API size_t ZSTD_freeDDict(ZSTD_DDict* ddict);
+
+/*! ZSTD_decompress_usingDDict() :
+ * Decompression using a digested Dictionary.
+ * Recommended when same dictionary is used multiple times. */
+ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_DDict* ddict);
+
+
+/********************************
+ * Dictionary helper functions
+ *******************************/
+
+/*! ZSTD_getDictID_fromDict() :
+ * Provides the dictID stored within dictionary.
+ * if @return == 0, the dictionary is not conformant with Zstandard specification.
+ * It can still be loaded, but as a content-only dictionary. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
+
+/*! ZSTD_getDictID_fromDDict() :
+ * Provides the dictID of the dictionary loaded into `ddict`.
+ * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+ * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
+
+/*! ZSTD_getDictID_fromFrame() :
+ * Provides the dictID required to decompressed the frame stored within `src`.
+ * If @return == 0, the dictID could not be decoded.
+ * This could for one of the following reasons :
+ * - The frame does not require a dictionary to be decoded (most common case).
+ * - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
+ * Note : this use case also happens when using a non-conformant dictionary.
+ * - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
+ * - This is not a Zstandard frame.
+ * When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
+
+
+/*******************************************************************************
+ * Advanced dictionary and prefix API
+ *
+ * This API allows dictionaries to be used with ZSTD_compress2(),
+ * ZSTD_compressStream2(), and ZSTD_decompress(). Dictionaries are sticky, and
+ * only reset with the context is reset with ZSTD_reset_parameters or
+ * ZSTD_reset_session_and_parameters. Prefixes are single-use.
+ ******************************************************************************/
+
+
+/*! ZSTD_CCtx_loadDictionary() :
+ * Create an internal CDict from `dict` buffer.
+ * Decompression will have to use same dictionary.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Loading a NULL (or 0-size) dictionary invalidates previous dictionary,
+ * meaning "return to no-dictionary mode".
+ * Note 1 : Dictionary is sticky, it will be used for all future compressed frames.
+ * To return to "no-dictionary" situation, load a NULL dictionary (or reset parameters).
+ * Note 2 : Loading a dictionary involves building tables.
+ * It's also a CPU consuming operation, with non-negligible impact on latency.
+ * Tables are dependent on compression parameters, and for this reason,
+ * compression parameters can no longer be changed after loading a dictionary.
+ * Note 3 :`dict` content will be copied internally.
+ * Use experimental ZSTD_CCtx_loadDictionary_byReference() to reference content instead.
+ * In such a case, dictionary buffer must outlive its users.
+ * Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
+ * to precisely select how dictionary content must be interpreted. */
+ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
+
+/*! ZSTD_CCtx_refCDict() :
+ * Reference a prepared dictionary, to be used for all next compressed frames.
+ * Note that compression parameters are enforced from within CDict,
+ * and supersede any compression parameter previously set within CCtx.
+ * The parameters ignored are labled as "superseded-by-cdict" in the ZSTD_cParameter enum docs.
+ * The ignored parameters will be used again if the CCtx is returned to no-dictionary mode.
+ * The dictionary will remain valid for future compressed frames using same CCtx.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special : Referencing a NULL CDict means "return to no-dictionary mode".
+ * Note 1 : Currently, only one dictionary can be managed.
+ * Referencing a new dictionary effectively "discards" any previous one.
+ * Note 2 : CDict is just referenced, its lifetime must outlive its usage within CCtx. */
+ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
+
+/*! ZSTD_CCtx_refPrefix() :
+ * Reference a prefix (single-usage dictionary) for next compressed frame.
+ * A prefix is **only used once**. Tables are discarded at end of frame (ZSTD_e_end).
+ * Decompression will need same prefix to properly regenerate data.
+ * Compressing with a prefix is similar in outcome as performing a diff and compressing it,
+ * but performs much faster, especially during decompression (compression speed is tunable with compression level).
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
+ * Note 1 : Prefix buffer is referenced. It **must** outlive compression.
+ * Its content must remain unmodified during compression.
+ * Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
+ * ensure that the window size is large enough to contain the entire source.
+ * See ZSTD_c_windowLog.
+ * Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
+ * It's a CPU consuming operation, with non-negligible impact on latency.
+ * If there is a need to use the same prefix multiple times, consider loadDictionary instead.
+ * Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dm_rawContent).
+ * Use experimental ZSTD_CCtx_refPrefix_advanced() to alter dictionary interpretation. */
+ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
+ const void* prefix, size_t prefixSize);
/*! ZSTD_DCtx_loadDictionary() :
* Create an internal DDict from dict buffer,
@@ -910,15 +954,32 @@ ZSTDLIB_API size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
ZSTDLIB_API size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx,
const void* prefix, size_t prefixSize);
-/*! ZSTD_DCtx_reset() :
- * Return a DCtx to clean state.
- * Session and parameters can be reset jointly or separately.
- * Parameters can only be reset when no active frame is being decompressed.
- * @return : 0, or an error code, which can be tested with ZSTD_isError()
- */
-ZSTDLIB_API size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);
+/* === Memory management === */
+
+/*! ZSTD_sizeof_*() :
+ * These functions give the _current_ memory usage of selected object.
+ * Note that object memory usage can evolve (increase or decrease) over time. */
+ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
+ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
+ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
+ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
+ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
+
+#endif /* ZSTD_H_235446 */
+
+/****************************************************************************************
+ * ADVANCED AND EXPERIMENTAL FUNCTIONS
+ ****************************************************************************************
+ * The definitions in the following section are considered experimental.
+ * They are provided for advanced scenarios.
+ * They should never be used with a dynamic library, as prototypes may change in the future.
+ * Use them only in association with static linking.
+ * ***************************************************************************************/
+#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
+#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
/****************************************************************************************
* experimental API (static linking only)
@@ -962,7 +1023,7 @@ ZSTDLIB_API size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);
#define ZSTD_WINDOWLOG_LIMIT_DEFAULT 27 /* by default, the streaming decoder will refuse any frame
* requiring larger than (1<<ZSTD_WINDOWLOG_LIMIT_DEFAULT) window size,
* to preserve host's memory from unreasonable requirements.
- * This limit can be overriden using ZSTD_DCtx_setParameter(,ZSTD_d_windowLogMax,).
+ * This limit can be overridden using ZSTD_DCtx_setParameter(,ZSTD_d_windowLogMax,).
* The limit does not apply for one-pass decoders (such as ZSTD_decompress()), since no additional memory is allocated */
@@ -1064,15 +1125,24 @@ typedef enum {
ZSTD_dictForceCopy = 2, /* Always copy the dictionary. */
} ZSTD_dictAttachPref_e;
+typedef enum {
+ ZSTD_lcm_auto = 0, /**< Automatically determine the compression mode based on the compression level.
+ * Negative compression levels will be uncompressed, and positive compression
+ * levels will be compressed. */
+ ZSTD_lcm_huffman = 1, /**< Always attempt Huffman compression. Uncompressed literals will still be
+ * emitted if Huffman compression is not profitable. */
+ ZSTD_lcm_uncompressed = 2, /**< Always emit uncompressed literals. */
+} ZSTD_literalCompressionMode_e;
+
/***************************************
* Frame size functions
***************************************/
/*! ZSTD_findDecompressedSize() :
- * `src` should point the start of a series of ZSTD encoded and/or skippable frames
+ * `src` should point to the start of a series of ZSTD encoded and/or skippable frames
* `srcSize` must be the _exact_ size of this series
- * (i.e. there should be a frame boundary exactly at `srcSize` bytes after `src`)
+ * (i.e. there should be a frame boundary at `src + srcSize`)
* @return : - decompressed size of all data in all successive frames
* - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
* - if an error occurred: ZSTD_CONTENTSIZE_ERROR
@@ -1092,6 +1162,21 @@ typedef enum {
* however it does mean that all frame data must be present and valid. */
ZSTDLIB_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
+/** ZSTD_decompressBound() :
+ * `src` should point to the start of a series of ZSTD encoded and/or skippable frames
+ * `srcSize` must be the _exact_ size of this series
+ * (i.e. there should be a frame boundary at `src + srcSize`)
+ * @return : - upper-bound for the decompressed size of all data in all successive frames
+ * - if an error occured: ZSTD_CONTENTSIZE_ERROR
+ *
+ * note 1 : an error can occur if `src` contains an invalid or incorrectly formatted frame.
+ * note 2 : the upper-bound is exact when the decompressed size field is available in every ZSTD encoded frame of `src`.
+ * in this case, `ZSTD_findDecompressedSize` and `ZSTD_decompressBound` return the same value.
+ * note 3 : when the decompressed size field isn't available, the upper-bound for that frame is calculated by:
+ * upper-bound = # blocks * min(128 KB, Window_Size)
+ */
+ZSTDLIB_API unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize);
+
/*! ZSTD_frameHeaderSize() :
* srcSize must be >= ZSTD_FRAMEHEADERSIZE_PREFIX.
* @return : size of the Frame Header,
@@ -1110,7 +1195,7 @@ ZSTDLIB_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
* It will also consider src size to be arbitrarily "large", which is worst case.
* If srcSize is known to always be small, ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
* ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
- * ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
+ * ZSTD_estimateCCtxSize_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 : CCtx size estimation is only correct for single-threaded compression. */
ZSTDLIB_API size_t ZSTD_estimateCCtxSize(int compressionLevel);
ZSTDLIB_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
@@ -1122,7 +1207,7 @@ ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void);
* It will also consider src size to be arbitrarily "large", which is worst case.
* 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_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
+ * 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.
* This information can be passed manually, using ZSTD_estimateDStreamSize,
@@ -1226,22 +1311,26 @@ ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictS
ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
/*! ZSTD_getCParams() :
-* @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
-* `estimatedSrcSize` value is optional, select 0 if not known */
+ * @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
+ * `estimatedSrcSize` value is optional, select 0 if not known */
ZSTDLIB_API ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
/*! ZSTD_getParams() :
-* same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
-* All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 */
+ * same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
+ * All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 */
ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
/*! ZSTD_checkCParams() :
-* Ensure param values remain within authorized range */
+ * Ensure param values remain within authorized range.
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()) */
ZSTDLIB_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
/*! ZSTD_adjustCParams() :
* optimize params for a given `srcSize` and `dictSize`.
- * both values are optional, select `0` if unknown. */
+ * `srcSize` can be unknown, in which case use ZSTD_CONTENTSIZE_UNKNOWN.
+ * `dictSize` must be `0` when there is no dictionary.
+ * cPar can be invalid : all parameters will be clamped within valid range in the @return struct.
+ * This function never fails (wide contract) */
ZSTDLIB_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
/*! ZSTD_compress_advanced() :
@@ -1314,6 +1403,12 @@ ZSTDLIB_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* pre
* See the comments on that enum for an explanation of the feature. */
#define ZSTD_c_forceAttachDict ZSTD_c_experimentalParam4
+/* Controls how the literals are compressed (default is auto).
+ * The value must be of type ZSTD_literalCompressionMode_e.
+ * See ZSTD_literalCompressionMode_t enum definition for details.
+ */
+#define ZSTD_c_literalCompressionMode ZSTD_c_experimentalParam5
+
/*! ZSTD_CCtx_getParameter() :
* Get the requested compression parameter value, selected by enum ZSTD_cParameter,
* and store it into int* value.
@@ -1325,10 +1420,10 @@ ZSTDLIB_API size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param
/*! ZSTD_CCtx_params :
* Quick howto :
* - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
- * - ZSTD_CCtxParam_setParameter() : Push parameters one by one into
- * an existing ZSTD_CCtx_params structure.
- * This is similar to
- * ZSTD_CCtx_setParameter().
+ * - ZSTD_CCtxParams_setParameter() : Push parameters one by one into
+ * an existing ZSTD_CCtx_params structure.
+ * This is similar to
+ * ZSTD_CCtx_setParameter().
* - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
* an existing CCtx.
* These parameters will be applied to
@@ -1359,20 +1454,20 @@ ZSTDLIB_API size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compre
*/
ZSTDLIB_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
-/*! ZSTD_CCtxParam_setParameter() :
+/*! ZSTD_CCtxParams_setParameter() :
* Similar to ZSTD_CCtx_setParameter.
* Set one compression parameter, selected by enum ZSTD_cParameter.
* Parameters must be applied to a ZSTD_CCtx using ZSTD_CCtx_setParametersUsingCCtxParams().
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
*/
-ZSTDLIB_API size_t ZSTD_CCtxParam_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int value);
+ZSTDLIB_API size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int value);
-/*! ZSTD_CCtxParam_getParameter() :
+/*! ZSTD_CCtxParams_getParameter() :
* Similar to ZSTD_CCtx_getParameter.
* Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
*/
-ZSTDLIB_API size_t ZSTD_CCtxParam_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
+ZSTDLIB_API size_t ZSTD_CCtxParams_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
/*! ZSTD_CCtx_setParametersUsingCCtxParams() :
* Apply a set of ZSTD_CCtx_params to the compression context.
@@ -1415,31 +1510,6 @@ ZSTDLIB_API unsigned ZSTD_isFrame(const void* buffer, size_t size);
* it must remain read accessible throughout the lifetime of DDict */
ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);
-
-/*! ZSTD_getDictID_fromDict() :
- * Provides the dictID stored within dictionary.
- * if @return == 0, the dictionary is not conformant with Zstandard specification.
- * It can still be loaded, but as a content-only dictionary. */
-ZSTDLIB_API unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
-
-/*! ZSTD_getDictID_fromDDict() :
- * Provides the dictID of the dictionary loaded into `ddict`.
- * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
- * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
-ZSTDLIB_API unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
-
-/*! ZSTD_getDictID_fromFrame() :
- * Provides the dictID required to decompressed the frame stored within `src`.
- * If @return == 0, the dictID could not be decoded.
- * This could for one of the following reasons :
- * - The frame does not require a dictionary to be decoded (most common case).
- * - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
- * Note : this use case also happens when using a non-conformant dictionary.
- * - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
- * - This is not a Zstandard frame.
- * When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. */
-ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
-
/*! ZSTD_DCtx_loadDictionary_byReference() :
* Same as ZSTD_DCtx_loadDictionary(),
* but references `dict` content instead of copying it into `dctx`.
@@ -1501,14 +1571,68 @@ ZSTDLIB_API size_t ZSTD_decompressStream_simpleArgs (
********************************************************************/
/*===== Advanced Streaming compression functions =====*/
-ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct. If it is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs, "0" also disables frame content size field. It may be enabled in the future. */
-ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /**< creates of an internal CDict (incompatible with static CCtx), except if dict == NULL or dictSize < 8, in which case no dict is used. Note: dict is loaded with ZSTD_dm_auto (treated as a full zstd dictionary if it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.*/
+/**! ZSTD_initCStream_srcSize() :
+ * This function is deprecated, and equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ *
+ * pledgedSrcSize must be correct. If it is not known at init time, use
+ * ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs,
+ * "0" also disables frame content size field. It may be enabled in the future.
+ */
+ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize);
+/**! ZSTD_initCStream_usingDict() :
+ * This function is deprecated, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ * ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+ *
+ * Creates of an internal CDict (incompatible with static CCtx), except if
+ * dict == NULL or dictSize < 8, in which case no dict is used.
+ * Note: dict is loaded with ZSTD_dm_auto (treated as a full zstd dictionary if
+ * it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
+ */
+ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
+/**! ZSTD_initCStream_advanced() :
+ * This function is deprecated, and is approximately equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setZstdParams(zcs, params); // Set the zstd params and leave the rest as-is
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+ *
+ * pledgedSrcSize must be correct. If srcSize is not known at init time, use
+ * value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy.
+ */
ZSTDLIB_API size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
- ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy. */
-ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict); /**< note : cdict will just be referenced, and must outlive compression session */
-ZSTDLIB_API size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize); /**< same as ZSTD_initCStream_usingCDict(), with control over frame parameters. pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. */
+ ZSTD_parameters params, unsigned long long pledgedSrcSize);
+/**! ZSTD_initCStream_usingCDict() :
+ * This function is deprecated, and equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, cdict);
+ *
+ * note : cdict will just be referenced, and must outlive compression session
+ */
+ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);
+/**! ZSTD_initCStream_usingCDict_advanced() :
+ * This function is deprecated, and is approximately equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setZstdFrameParams(zcs, fParams); // Set the zstd frame params and leave the rest as-is
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * ZSTD_CCtx_refCDict(zcs, cdict);
+ *
+ * same as ZSTD_initCStream_usingCDict(), with control over frame parameters.
+ * pledgedSrcSize must be correct. If srcSize is not known at init time, use
+ * value ZSTD_CONTENTSIZE_UNKNOWN.
+ */
+ZSTDLIB_API size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize);
/*! ZSTD_resetCStream() :
+ * This function is deprecated, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ *
* 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.
* Note that zcs must be init at least once before using ZSTD_resetCStream().
@@ -1555,9 +1679,32 @@ ZSTDLIB_API size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx);
/*===== Advanced Streaming decompression functions =====*/
-ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /**< note: no dictionary will be used if dict == NULL or dictSize < 8 */
-ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); /**< note : ddict is referenced, it must outlive decompression session */
-ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds); /**< re-use decompression parameters from previous init; saves dictionary loading */
+/**
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ * ZSTD_DCtx_loadDictionary(zds, dict, dictSize);
+ *
+ * note: no dictionary will be used if dict == NULL or dictSize < 8
+ */
+ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
+/**
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ * ZSTD_DCtx_refDDict(zds, ddict);
+ *
+ * note : ddict is referenced, it must outlive decompression session
+ */
+ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);
+/**
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ *
+ * re-use decompression parameters from previous init; saves dictionary loading
+ */
+ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds);
/*********************************************************************