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ZSTD_getFrameContentSize() is promoted to "stable" status

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Yann Collet 2017-06-29 05:18:09 -07:00
parent 590937df20
commit acbef3decd
2 changed files with 51 additions and 45 deletions
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5
NEWS
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@ -1,12 +1,15 @@
v1.3.0
cli : new : `--list` command, by Paul Cruz
cli : changed : xz/lzma support enabled by default
cli : changed : `-t *` continue processing list after a decompression error
API : added : ZSTD_versionString()
API : promoted to stable status : ZSTD_getFrameContentSize(), by Sean Purcell
API exp : new advanced API : ZSTD_compress_generic(), ZSTD_CCtx_setParameter()
API exp : new : API for static or external allocation : ZSTD_initStatic?Ctx()
API exp : added : ZSTD_decompressBegin_usingDDict(), requested by Guy Riddle (#700)
API exp : clarified memory estimation / measurement functions.
API exp : changed : strongest strategy renamed ZSTD_btultra, fastest strategy ZSTD_fast set to 1
API exp : clarified presentation of memory estimation / measurement functions.
tools : decodecorpus can generate random dictionary-compressed samples, by Paul Cruz
new : contrib/seekable_format, demo and API, by Sean Purcell
changed : contrib/linux-kernel, updated version and license, by Nick Terrell

91
lib/zstd.h
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@ -68,7 +68,7 @@ ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< useful to check dll versio
#define ZSTD_QUOTE(str) #str
#define ZSTD_EXPAND_AND_QUOTE(str) ZSTD_QUOTE(str)
#define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION)
ZSTDLIB_API const char* ZSTD_versionString(void); /* >= v1.3.0 */
ZSTDLIB_API const char* ZSTD_versionString(void); /* v1.3.0 */
/***************************************
@ -92,27 +92,41 @@ ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,
const void* src, size_t compressedSize);
/*! ZSTD_getDecompressedSize() :
* NOTE: This function is planned to be obsolete, in favor of ZSTD_getFrameContentSize().
* ZSTD_getFrameContentSize() works the same way,
* returning the decompressed size of a single frame,
* but distinguishes empty frames from frames with an unknown size, or errors.
*
* 'src' is the start of a zstd compressed frame.
* @return : content size to be decompressed, as a 64-bits value _if known_, 0 otherwise.
* note 1 : decompressed size is an optional field, it may not be present, typically in streaming mode.
* When `return==0`, data to decompress could be any size.
/*! ZSTD_getFrameContentSize() : v1.3.0
* `src` should point to the start of a ZSTD encoded frame.
* `srcSize` must be at least as large as the frame header.
* hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
* @return : - decompressed size of the frame in `src`, if known
* - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
* - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
* note 1 : a 0 return value means the frame is valid but "empty".
* note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
* When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
* In which case, it's necessary to use streaming mode to decompress data.
* Optionally, application can use ZSTD_decompress() while relying on implied limits.
* (For example, data may be necessarily cut into blocks <= 16 KB).
* note 2 : decompressed size is always present when compression is done with ZSTD_compress()
* note 3 : decompressed size can be very large (64-bits value),
* Optionally, application can rely on some implicit limit,
* as ZSTD_decompress() only needs an upper bound of decompressed size.
* (For example, data could be necessarily cut into blocks <= 16 KB).
* note 3 : decompressed size is always present when compression is done with ZSTD_compress()
* note 4 : decompressed size can be very large (64-bits value),
* potentially larger than what local system can handle as a single memory segment.
* In which case, it's necessary to use streaming mode to decompress data.
* note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
* Always ensure result fits within application's authorized limits.
* note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
* Always ensure return value fits within application's authorized limits.
* Each application can set its own limits.
* note 5 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameHeader() to know more. */
* note 6 : This function replaces ZSTD_getDecompressedSize() */
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
/*! ZSTD_getDecompressedSize() :
* NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
* Both functions work the same way,
* but ZSTD_getDecompressedSize() blends
* "empty", "unknown" and "error" results in the same return value (0),
* while ZSTD_getFrameContentSize() distinguishes them.
*
* 'src' is the start of a zstd compressed frame.
* @return : content size to be decompressed, as a 64-bits value _if known and not empty_, 0 otherwise. */
ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
@ -291,7 +305,7 @@ typedef struct ZSTD_outBuffer_s {
* *******************************************************************/
typedef ZSTD_CCtx ZSTD_CStream; /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
/* But continue to distinguish them for compatibility with versions <= v1.2.0 */
/* Continue to distinguish them for compatibility with versions <= v1.2.0 */
/*===== ZSTD_CStream management functions =====*/
ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
@ -330,7 +344,7 @@ ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output
* *******************************************************************************/
typedef ZSTD_DCtx ZSTD_DStream; /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
/* But continue to distinguish them for compatibility with versions <= v1.2.0 */
/* Continue to distinguish them for compatibility with versions <= v1.2.0 */
/*===== ZSTD_DStream management functions =====*/
ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
@ -349,8 +363,8 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output
/****************************************************************************************
* START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
* The definitions in this section are considered experimental.
* They should never be used with a dynamic library, as they may change in the future.
* They are provided for advanced usages.
* They should never be used with a dynamic library, as prototypes may change in the future.
* They are provided for advanced scenarios.
* Use them only in association with static linking.
* ***************************************************************************************/
@ -381,8 +395,8 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output
#define ZSTD_FRAMEHEADERSIZE_MAX 18 /* for static allocation */
#define ZSTD_FRAMEHEADERSIZE_MIN 6
static const size_t ZSTD_frameHeaderSize_prefix = 5; /* minimum input size to know frame header size */
static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
static const size_t ZSTD_skippableHeaderSize = 8; /* magic number + skippable frame length */
@ -433,26 +447,15 @@ static const ZSTD_customMem ZSTD_defaultCMem = { NULL, NULL, NULL };
/*! ZSTD_findFrameCompressedSize() :
* `src` should point to the start of a ZSTD encoded frame or skippable frame
* `srcSize` must be at least as large as the frame
* @return : the compressed size of the frame pointed to by `src`,
* @return : the compressed size of the first frame starting at `src`,
* suitable to pass to `ZSTD_decompress` or similar,
* or an error code if given invalid input. */
* or an error code if input is invalid */
ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
/*! ZSTD_getFrameContentSize() :
* `src` should point to the start of a ZSTD encoded frame.
* `srcSize` must be at least as large as the frame header.
* A value >= `ZSTD_frameHeaderSize_max` is guaranteed to be large enough.
* @return : - decompressed size of the frame pointed to be `src` if known
* - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
* - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
/*! ZSTD_findDecompressedSize() :
* `src` should point 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 `srcSize` bytes after `src`)
* `srcSize` must be the _exact_ size of this serie
* (i.e. there should be a frame boundary exactly at `srcSize` bytes after `src`)
* @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
@ -460,8 +463,6 @@ ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t
* note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
* When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
* In which case, it's necessary to use streaming mode to decompress data.
* Optionally, application can still use ZSTD_decompress() while relying on implied limits.
* (For example, data may be necessarily cut into blocks <= 16 KB).
* note 2 : decompressed size is always present when compression is done with ZSTD_compress()
* note 3 : decompressed size can be very large (64-bits value),
* potentially larger than what local system can handle as a single memory segment.
@ -470,7 +471,7 @@ ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t
* Always ensure result fits within application's authorized limits.
* Each application can set its own limits.
* note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
* read each contained frame header. This is efficient as most of the data is skipped,
* read each contained frame header. This is fast as most of the data is skipped,
* 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);
@ -478,7 +479,8 @@ ZSTDLIB_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t
* `src` should point to the start of a ZSTD frame
* `srcSize` must be >= ZSTD_frameHeaderSize_prefix.
* @return : size of the Frame Header */
size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
ZSTDLIB_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
/***************************************
* Context memory usage
@ -575,7 +577,7 @@ ZSTDLIB_API size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter par
ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
typedef enum { ZSTD_dm_auto=0, /* dictionary is "full" if it starts with ZSTD_MAGIC_DICTIONARY, rawContent otherwize */
typedef enum { ZSTD_dm_auto=0, /* dictionary is "full" if it starts with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
ZSTD_dm_rawContent, /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
ZSTD_dm_fullDict /* refuses to load a dictionary if it does not respect Zstandard's specification */
} ZSTD_dictMode_e;
@ -583,7 +585,8 @@ typedef enum { ZSTD_dm_auto=0, /* dictionary is "full" if it starts with
* Create a ZSTD_CDict using external alloc and free, and customized compression parameters */
ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
unsigned byReference, ZSTD_dictMode_e dictMode,
ZSTD_compressionParameters cParams, ZSTD_customMem customMem);
ZSTD_compressionParameters cParams,
ZSTD_customMem customMem);
/*! ZSTD_initStaticCDict_advanced() :
* Generate a digested dictionary in provided memory area.