Mercurial > public > mercurial-scm > hg-stable
diff contrib/python-zstandard/zstd/zstd.h @ 30822:b54a2984cdd4
zstd: vendor python-zstandard 0.6.0
Commit 63c68d6f5fc8de4afd9bde81b13b537beb4e47e8 from
https://github.com/indygreg/python-zstandard is imported without
modifications (other than removing unwanted files).
This includes minor performance and feature improvements. It also
changes the vendored zstd library from 1.1.1 to 1.1.2.
# no-check-commit
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 14 Jan 2017 19:41:43 -0800 |
parents | 2e484bdea8c4 |
children | c32454d69b85 |
line wrap: on
line diff
--- a/contrib/python-zstandard/zstd/zstd.h Sat Jan 14 20:05:15 2017 +0530 +++ b/contrib/python-zstandard/zstd/zstd.h Sat Jan 14 19:41:43 2017 -0800 @@ -7,24 +7,24 @@ * of patent rights can be found in the PATENTS file in the same directory. */ -#ifndef ZSTD_H_235446 -#define ZSTD_H_235446 - #if defined (__cplusplus) extern "C" { #endif +#ifndef ZSTD_H_235446 +#define ZSTD_H_235446 + /* ====== Dependency ======*/ #include <stddef.h> /* size_t */ -/* ====== Export for Windows ======*/ -/* -* ZSTD_DLL_EXPORT : -* Enable exporting of functions when building a Windows DLL -*/ -#if defined(_WIN32) && defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1) +/* ===== ZSTDLIB_API : control library symbols visibility ===== */ +#if defined(__GNUC__) && (__GNUC__ >= 4) +# define ZSTDLIB_API __attribute__ ((visibility ("default"))) +#elif defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1) # define ZSTDLIB_API __declspec(dllexport) +#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1) +# define ZSTDLIB_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/ #else # define ZSTDLIB_API #endif @@ -51,11 +51,9 @@ *********************************************************************************************************/ /*------ Version ------*/ -ZSTDLIB_API unsigned ZSTD_versionNumber (void); /**< returns version number of ZSTD */ - #define ZSTD_VERSION_MAJOR 1 #define ZSTD_VERSION_MINOR 1 -#define ZSTD_VERSION_RELEASE 1 +#define ZSTD_VERSION_RELEASE 2 #define ZSTD_LIB_VERSION ZSTD_VERSION_MAJOR.ZSTD_VERSION_MINOR.ZSTD_VERSION_RELEASE #define ZSTD_QUOTE(str) #str @@ -63,6 +61,7 @@ #define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION) #define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE) +ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< library version number; to be used when checking dll version */ /*************************************** @@ -72,7 +71,7 @@ Compresses `src` content as a single zstd compressed frame into already allocated `dst`. Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`. @return : compressed size written into `dst` (<= `dstCapacity), - or an error code if it fails (which can be tested using ZSTD_isError()) */ + or an error code if it fails (which can be tested using ZSTD_isError()). */ ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel); @@ -82,7 +81,7 @@ `dstCapacity` is an upper bound of originalSize. If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data. @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), - or an errorCode if it fails (which can be tested using ZSTD_isError()) */ + or an errorCode if it fails (which can be tested using ZSTD_isError()). */ ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity, const void* src, size_t compressedSize); @@ -116,16 +115,16 @@ * Explicit memory management ***************************************/ /*= Compression context -* When compressing many messages / blocks, +* When compressing many times, * it is recommended to allocate a context just once, and re-use it for each successive compression operation. -* This will make the situation much easier for the system's memory. +* This will make workload friendlier for system's memory. * Use one context per thread for parallel execution in multi-threaded environments. */ typedef struct ZSTD_CCtx_s ZSTD_CCtx; ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx(void); ZSTDLIB_API size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx); /*! ZSTD_compressCCtx() : - Same as ZSTD_compress(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()) */ + Same as ZSTD_compress(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()). */ ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel); /*= Decompression context */ @@ -134,7 +133,7 @@ ZSTDLIB_API size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); /*! ZSTD_decompressDCtx() : -* Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()) */ +* Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()). */ ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); @@ -143,7 +142,8 @@ ***************************/ /*! ZSTD_compress_usingDict() : * Compression using a predefined Dictionary (see dictBuilder/zdict.h). -* Note : This function load the dictionary, resulting in significant startup delay. */ +* Note : This function loads the dictionary, resulting in significant startup delay. +* Note : 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, @@ -153,7 +153,8 @@ /*! ZSTD_decompress_usingDict() : * Decompression using a predefined Dictionary (see dictBuilder/zdict.h). * Dictionary must be identical to the one used during compression. -* Note : This function load the dictionary, resulting in significant startup delay */ +* Note : This function loads the dictionary, resulting in significant startup delay. +* 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, @@ -169,17 +170,17 @@ * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once. * ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay. * ZSTD_CDict can be created once and used by multiple threads concurrently, as its usage is read-only. -* `dict` can be released after ZSTD_CDict creation */ +* `dict` can be released after ZSTD_CDict creation. */ ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel); /*! ZSTD_freeCDict() : -* Function frees memory allocated by ZSTD_createCDict() */ +* Function frees memory allocated by ZSTD_createCDict(). */ ZSTDLIB_API size_t ZSTD_freeCDict(ZSTD_CDict* CDict); /*! ZSTD_compress_usingCDict() : * Compression using a digested Dictionary. * Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times. -* Note that compression level is decided during dictionary creation */ +* Note that compression level is decided during dictionary creation. */ ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, @@ -190,7 +191,7 @@ /*! ZSTD_createDDict() : * Create a digested dictionary, ready to start decompression operation without startup delay. -* `dict` can be released after creation */ +* `dict` can be released after creation. */ ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize); /*! ZSTD_freeDDict() : @@ -198,7 +199,7 @@ ZSTDLIB_API size_t ZSTD_freeDDict(ZSTD_DDict* ddict); /*! ZSTD_decompress_usingDDict() : -* Decompression using a digested Dictionary +* Decompression using a digested Dictionary. * Faster startup than ZSTD_decompress_usingDict(), recommended when same dictionary is used multiple times. */ ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, @@ -236,20 +237,20 @@ * * Start a new compression by initializing ZSTD_CStream. * Use ZSTD_initCStream() to start a new compression operation. -* Use ZSTD_initCStream_usingDict() for a compression which requires a dictionary. +* Use ZSTD_initCStream_usingDict() or ZSTD_initCStream_usingCDict() for a compression which requires a dictionary (experimental section) * * Use ZSTD_compressStream() repetitively to consume input stream. * The function will automatically update both `pos` fields. * Note that it may not consume the entire input, in which case `pos < size`, * and it's up to the caller to present again remaining data. * @return : a size hint, preferred nb of bytes to use as input for next function call -* (it's just a hint, to help latency a little, any other value will work fine) -* (note : the size hint is guaranteed to be <= ZSTD_CStreamInSize() ) * or an error code, which can be tested using ZSTD_isError(). +* Note 1 : it's just a hint, to help latency a little, any other value will work fine. +* Note 2 : size hint is guaranteed to be <= ZSTD_CStreamInSize() * -* At any moment, it's possible to flush whatever data remains within buffer, using ZSTD_flushStream(). +* At any moment, it's possible to flush whatever data remains within internal buffer, using ZSTD_flushStream(). * `output->pos` will be updated. -* Note some content might still be left within internal buffer if `output->size` is too small. +* Note that some content might still be left within internal buffer if `output->size` is too small. * @return : nb of bytes still present within internal buffer (0 if it's empty) * or an error code, which can be tested using ZSTD_isError(). * @@ -258,15 +259,15 @@ * The epilogue is required for decoders to consider a frame completed. * Similar to ZSTD_flushStream(), it may not be able to flush the full content if `output->size` is too small. * In which case, call again ZSTD_endStream() to complete the flush. -* @return : nb of bytes still present within internal buffer (0 if it's empty) +* @return : nb of bytes still present within internal buffer (0 if it's empty, hence compression completed) * or an error code, which can be tested using ZSTD_isError(). * * *******************************************************************/ -/*===== Streaming compression functions ======*/ typedef struct ZSTD_CStream_s ZSTD_CStream; ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void); ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs); + 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); @@ -295,23 +296,25 @@ * If `output.pos < output.size`, decoder has flushed everything it could. * @return : 0 when a frame is completely decoded and fully flushed, * an error code, which can be tested using ZSTD_isError(), -* any other value > 0, which means there is still some work to do to complete the frame. -* The return value is a suggested next input size (just an hint, to help latency). +* any other value > 0, which means there is still some decoding to do to complete current frame. +* The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame. * *******************************************************************************/ -/*===== Streaming decompression functions =====*/ typedef struct ZSTD_DStream_s ZSTD_DStream; ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void); ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds); + 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 */ -#ifdef ZSTD_STATIC_LINKING_ONLY +#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY) +#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY /**************************************************************************************** * START OF ADVANCED AND EXPERIMENTAL FUNCTIONS @@ -403,15 +406,15 @@ * Gives the amount of memory used by a given ZSTD_sizeof_CDict */ ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict); -/*! ZSTD_getParams() : -* same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of a `ZSTD_compressionParameters`. -* All fields of `ZSTD_frameParameters` are set to default (0) */ -ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSize, size_t dictSize); +/*! ZSTD_getCParams() : +* @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_getCParams() : -* @return ZSTD_compressionParameters structure for a selected compression level and srcSize. -* `srcSize` value is optional, select 0 if not known */ -ZSTDLIB_API ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSize, 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 (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 */ @@ -433,6 +436,13 @@ /*--- Advanced decompression functions ---*/ +/*! ZSTD_isFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled. + * Note 3 : Skippable Frame Identifiers are considered valid. */ +ZSTDLIB_API unsigned ZSTD_isFrame(const void* buffer, size_t size); + /*! ZSTD_estimateDCtxSize() : * Gives the potential amount of memory allocated to create a ZSTD_DCtx */ ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void); @@ -449,6 +459,30 @@ * Gives the amount of memory used by a given ZSTD_DDict */ ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); +/*! 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. */ +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. */ +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 used ZSTD_getFrameParams(), which will provide a more precise error code. */ +unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize); + /******************************************************************** * Advanced streaming functions @@ -456,6 +490,7 @@ /*===== Advanced Streaming compression functions =====*/ ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem); +ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct */ ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); ZSTDLIB_API size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize is optional and can be zero == unknown */ @@ -631,10 +666,8 @@ ZSTDLIB_API size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize); /**< insert block into `dctx` history. Useful for uncompressed blocks */ -#endif /* ZSTD_STATIC_LINKING_ONLY */ +#endif /* ZSTD_H_ZSTD_STATIC_LINKING_ONLY */ #if defined (__cplusplus) } #endif - -#endif /* ZSTD_H_235446 */