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Yann Collet 2016-09-13 00:51:47 +02:00
parent 716a9e8bb3
commit ac175d46d4
1 changed files with 22 additions and 21 deletions
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43
lib/zstd.h
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@ -48,7 +48,7 @@ ZSTDLIB_API unsigned ZSTD_versionNumber (void);
* Simple API
***************************************/
/*! ZSTD_compress() :
Compresses `src` buffer into already allocated `dst`.
Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
@return : the number of bytes written into `dst` (<= `dstCapacity),
or an error code if it fails (which can be tested using ZSTD_isError()) */
@ -56,32 +56,33 @@ ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
int compressionLevel);
/*! ZSTD_getDecompressedSize() :
* @return : decompressed size as a 64-bits value _if known_, 0 otherwise.
* note 1 : 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 2 : decompressed size is an optional field, that may not be present.
* When `return==0`, data to decompress can have any size.
* In which case, it's necessary to use streaming mode to decompress data.
* Optionally, application may rely on its own implied limits.
* (For example, application data could be necessarily cut into blocks <= 16 KB).
* note 3 : decompressed size could be wrong or intentionally modified !
* Always ensure result fits within application's authorized limits !
* Each application can set its own limits.
* note 4 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. */
ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
/*! ZSTD_decompress() :
`compressedSize` : must be the _exact_ size of compressed input, otherwise decompression will fail.
`dstCapacity` must be equal or larger than originalSize (see ZSTD_getDecompressedSize() ).
If originalSize is unknown, and if there is no implied application-specific limitations,
it's preferable to use streaming mode to decompress data.
`compressedSize` : must be the _exact_ size of a single compressed frame.
`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()) */
ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,
const void* src, size_t compressedSize);
/*! ZSTD_getDecompressedSize() :
* '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, that may not be present, especially in streaming mode.
* When `return==0`, 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.
* 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.
* Each application can set its own limits.
* note 5 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. */
ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
/*====== Helper functions ======*/
ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */