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- /*
- LZ4F - LZ4-Frame library
- Header File
- Copyright (C) 2011-2020, Yann Collet.
- BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following disclaimer
- in the documentation and/or other materials provided with the
- distribution.
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- You can contact the author at :
- - LZ4 source repository : https://github.com/lz4/lz4
- - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
- */
- /* LZ4F is a stand-alone API able to create and decode LZ4 frames
- * conformant with specification v1.6.1 in doc/lz4_Frame_format.md .
- * Generated frames are compatible with `lz4` CLI.
- *
- * LZ4F also offers streaming capabilities.
- *
- * lz4.h is not required when using lz4frame.h,
- * except to extract common constants such as LZ4_VERSION_NUMBER.
- * */
- #ifndef LZ4F_H_09782039843
- #define LZ4F_H_09782039843
- #if defined (__cplusplus)
- extern "C" {
- #endif
- /* --- Dependency --- */
- #include <stddef.h> /* size_t */
- /**
- * Introduction
- *
- * lz4frame.h implements LZ4 frame specification: see doc/lz4_Frame_format.md .
- * LZ4 Frames are compatible with `lz4` CLI,
- * and designed to be interoperable with any system.
- **/
- /*-***************************************************************
- * Compiler specifics
- *****************************************************************/
- /* LZ4_DLL_EXPORT :
- * Enable exporting of functions when building a Windows DLL
- * LZ4FLIB_VISIBILITY :
- * Control library symbols visibility.
- */
- #ifndef LZ4FLIB_VISIBILITY
- # if defined(__GNUC__) && (__GNUC__ >= 4)
- # define LZ4FLIB_VISIBILITY __attribute__ ((visibility ("default")))
- # else
- # define LZ4FLIB_VISIBILITY
- # endif
- #endif
- #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
- # define LZ4FLIB_API __declspec(dllexport) LZ4FLIB_VISIBILITY
- #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
- # define LZ4FLIB_API __declspec(dllimport) LZ4FLIB_VISIBILITY
- #else
- # define LZ4FLIB_API LZ4FLIB_VISIBILITY
- #endif
- #ifdef LZ4F_DISABLE_DEPRECATE_WARNINGS
- # define LZ4F_DEPRECATE(x) x
- #else
- # if defined(_MSC_VER)
- # define LZ4F_DEPRECATE(x) x /* __declspec(deprecated) x - only works with C++ */
- # elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
- # define LZ4F_DEPRECATE(x) x __attribute__((deprecated))
- # else
- # define LZ4F_DEPRECATE(x) x /* no deprecation warning for this compiler */
- # endif
- #endif
- /*-************************************
- * Error management
- **************************************/
- typedef size_t LZ4F_errorCode_t;
- LZ4FLIB_API unsigned LZ4F_isError(LZ4F_errorCode_t code); /**< tells when a function result is an error code */
- LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /**< return error code string; for debugging */
- /*-************************************
- * Frame compression types
- ************************************* */
- /* #define LZ4F_ENABLE_OBSOLETE_ENUMS // uncomment to enable obsolete enums */
- #ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
- # define LZ4F_OBSOLETE_ENUM(x) , LZ4F_DEPRECATE(x) = LZ4F_##x
- #else
- # define LZ4F_OBSOLETE_ENUM(x)
- #endif
- /* The larger the block size, the (slightly) better the compression ratio,
- * though there are diminishing returns.
- * Larger blocks also increase memory usage on both compression and decompression sides.
- */
- typedef enum {
- LZ4F_default=0,
- LZ4F_max64KB=4,
- LZ4F_max256KB=5,
- LZ4F_max1MB=6,
- LZ4F_max4MB=7
- LZ4F_OBSOLETE_ENUM(max64KB)
- LZ4F_OBSOLETE_ENUM(max256KB)
- LZ4F_OBSOLETE_ENUM(max1MB)
- LZ4F_OBSOLETE_ENUM(max4MB)
- } LZ4F_blockSizeID_t;
- /* Linked blocks sharply reduce inefficiencies when using small blocks,
- * they compress better.
- * However, some LZ4 decoders are only compatible with independent blocks */
- typedef enum {
- LZ4F_blockLinked=0,
- LZ4F_blockIndependent
- LZ4F_OBSOLETE_ENUM(blockLinked)
- LZ4F_OBSOLETE_ENUM(blockIndependent)
- } LZ4F_blockMode_t;
- typedef enum {
- LZ4F_noContentChecksum=0,
- LZ4F_contentChecksumEnabled
- LZ4F_OBSOLETE_ENUM(noContentChecksum)
- LZ4F_OBSOLETE_ENUM(contentChecksumEnabled)
- } LZ4F_contentChecksum_t;
- typedef enum {
- LZ4F_noBlockChecksum=0,
- LZ4F_blockChecksumEnabled
- } LZ4F_blockChecksum_t;
- typedef enum {
- LZ4F_frame=0,
- LZ4F_skippableFrame
- LZ4F_OBSOLETE_ENUM(skippableFrame)
- } LZ4F_frameType_t;
- #ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
- typedef LZ4F_blockSizeID_t blockSizeID_t;
- typedef LZ4F_blockMode_t blockMode_t;
- typedef LZ4F_frameType_t frameType_t;
- typedef LZ4F_contentChecksum_t contentChecksum_t;
- #endif
- /*! LZ4F_frameInfo_t :
- * makes it possible to set or read frame parameters.
- * Structure must be first init to 0, using memset() or LZ4F_INIT_FRAMEINFO,
- * setting all parameters to default.
- * It's then possible to update selectively some parameters */
- typedef struct {
- LZ4F_blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB; 0 == default */
- LZ4F_blockMode_t blockMode; /* LZ4F_blockLinked, LZ4F_blockIndependent; 0 == default */
- LZ4F_contentChecksum_t contentChecksumFlag; /* 1: frame terminated with 32-bit checksum of decompressed data; 0: disabled (default) */
- LZ4F_frameType_t frameType; /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
- unsigned long long contentSize; /* Size of uncompressed content ; 0 == unknown */
- unsigned dictID; /* Dictionary ID, sent by compressor to help decoder select correct dictionary; 0 == no dictID provided */
- LZ4F_blockChecksum_t blockChecksumFlag; /* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */
- } LZ4F_frameInfo_t;
- #define LZ4F_INIT_FRAMEINFO { LZ4F_default, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame, 0ULL, 0U, LZ4F_noBlockChecksum } /* v1.8.3+ */
- /*! LZ4F_preferences_t :
- * makes it possible to supply advanced compression instructions to streaming interface.
- * Structure must be first init to 0, using memset() or LZ4F_INIT_PREFERENCES,
- * setting all parameters to default.
- * All reserved fields must be set to zero. */
- typedef struct {
- LZ4F_frameInfo_t frameInfo;
- int compressionLevel; /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
- unsigned autoFlush; /* 1: always flush; reduces usage of internal buffers */
- unsigned favorDecSpeed; /* 1: parser favors decompression speed vs compression ratio. Only works for high compression modes (>= LZ4HC_CLEVEL_OPT_MIN) */ /* v1.8.2+ */
- unsigned reserved[3]; /* must be zero for forward compatibility */
- } LZ4F_preferences_t;
- #define LZ4F_INIT_PREFERENCES { LZ4F_INIT_FRAMEINFO, 0, 0u, 0u, { 0u, 0u, 0u } } /* v1.8.3+ */
- /*-*********************************
- * Simple compression function
- ***********************************/
- LZ4FLIB_API int LZ4F_compressionLevel_max(void); /* v1.8.0+ */
- /*! LZ4F_compressFrameBound() :
- * Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences.
- * `preferencesPtr` is optional. It can be replaced by NULL, in which case, the function will assume default preferences.
- * Note : this result is only usable with LZ4F_compressFrame().
- * It may also be relevant to LZ4F_compressUpdate() _only if_ no flush() operation is ever performed.
- */
- LZ4FLIB_API size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
- /*! LZ4F_compressFrame() :
- * Compress an entire srcBuffer into a valid LZ4 frame.
- * dstCapacity MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
- * The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
- * @return : number of bytes written into dstBuffer.
- * or an error code if it fails (can be tested using LZ4F_isError())
- */
- LZ4FLIB_API size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
- const void* srcBuffer, size_t srcSize,
- const LZ4F_preferences_t* preferencesPtr);
- /*-***********************************
- * Advanced compression functions
- *************************************/
- typedef struct LZ4F_cctx_s LZ4F_cctx; /* incomplete type */
- typedef LZ4F_cctx* LZ4F_compressionContext_t; /* for compatibility with older APIs, prefer using LZ4F_cctx */
- typedef struct {
- unsigned stableSrc; /* 1 == src content will remain present on future calls to LZ4F_compress(); skip copying src content within tmp buffer */
- unsigned reserved[3];
- } LZ4F_compressOptions_t;
- /*--- Resource Management ---*/
- #define LZ4F_VERSION 100 /* This number can be used to check for an incompatible API breaking change */
- LZ4FLIB_API unsigned LZ4F_getVersion(void);
- /*! LZ4F_createCompressionContext() :
- * The first thing to do is to create a compressionContext object,
- * which will keep track of operation state during streaming compression.
- * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version,
- * and a pointer to LZ4F_cctx*, to write the resulting pointer into.
- * @version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL.
- * The function provides a pointer to a fully allocated LZ4F_cctx object.
- * @cctxPtr MUST be != NULL.
- * If @return != zero, context creation failed.
- * A created compression context can be employed multiple times for consecutive streaming operations.
- * Once all streaming compression jobs are completed,
- * the state object can be released using LZ4F_freeCompressionContext().
- * Note1 : LZ4F_freeCompressionContext() is always successful. Its return value can be ignored.
- * Note2 : LZ4F_freeCompressionContext() works fine with NULL input pointers (do nothing).
- **/
- LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
- LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
- /*---- Compression ----*/
- #define LZ4F_HEADER_SIZE_MIN 7 /* LZ4 Frame header size can vary, depending on selected parameters */
- #define LZ4F_HEADER_SIZE_MAX 19
- /* Size in bytes of a block header in little-endian format. Highest bit indicates if block data is uncompressed */
- #define LZ4F_BLOCK_HEADER_SIZE 4
- /* Size in bytes of a block checksum footer in little-endian format. */
- #define LZ4F_BLOCK_CHECKSUM_SIZE 4
- /* Size in bytes of the content checksum. */
- #define LZ4F_CONTENT_CHECKSUM_SIZE 4
- /*! LZ4F_compressBegin() :
- * will write the frame header into dstBuffer.
- * dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
- * `prefsPtr` is optional : you can provide NULL as argument, all preferences will then be set to default.
- * @return : number of bytes written into dstBuffer for the header
- * or an error code (which can be tested using LZ4F_isError())
- */
- LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const LZ4F_preferences_t* prefsPtr);
- /*! LZ4F_compressBound() :
- * Provides minimum dstCapacity required to guarantee success of
- * LZ4F_compressUpdate(), given a srcSize and preferences, for a worst case scenario.
- * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() instead.
- * Note that the result is only valid for a single invocation of LZ4F_compressUpdate().
- * When invoking LZ4F_compressUpdate() multiple times,
- * if the output buffer is gradually filled up instead of emptied and re-used from its start,
- * one must check if there is enough remaining capacity before each invocation, using LZ4F_compressBound().
- * @return is always the same for a srcSize and prefsPtr.
- * prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario.
- * tech details :
- * @return if automatic flushing is not enabled, includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes.
- * It also includes frame footer (ending + checksum), since it might be generated by LZ4F_compressEnd().
- * @return doesn't include frame header, as it was already generated by LZ4F_compressBegin().
- */
- LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
- /*! LZ4F_compressUpdate() :
- * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
- * Important rule: dstCapacity MUST be large enough to ensure operation success even in worst case situations.
- * This value is provided by LZ4F_compressBound().
- * If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
- * After an error, the state is left in a UB state, and must be re-initialized or freed.
- * If previously an uncompressed block was written, buffered data is flushed
- * before appending compressed data is continued.
- * `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
- * @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
- * or an error code if it fails (which can be tested using LZ4F_isError())
- */
- LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const void* srcBuffer, size_t srcSize,
- const LZ4F_compressOptions_t* cOptPtr);
- /*! LZ4F_flush() :
- * When data must be generated and sent immediately, without waiting for a block to be completely filled,
- * it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
- * `dstCapacity` must be large enough to ensure the operation will be successful.
- * `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
- * @return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx)
- * or an error code if it fails (which can be tested using LZ4F_isError())
- * Note : LZ4F_flush() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr).
- */
- LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const LZ4F_compressOptions_t* cOptPtr);
- /*! LZ4F_compressEnd() :
- * To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
- * It will flush whatever data remained within `cctx` (like LZ4_flush())
- * and properly finalize the frame, with an endMark and a checksum.
- * `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
- * @return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark),
- * or an error code if it fails (which can be tested using LZ4F_isError())
- * Note : LZ4F_compressEnd() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr).
- * A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
- */
- LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const LZ4F_compressOptions_t* cOptPtr);
- /*-*********************************
- * Decompression functions
- ***********************************/
- typedef struct LZ4F_dctx_s LZ4F_dctx; /* incomplete type */
- typedef LZ4F_dctx* LZ4F_decompressionContext_t; /* compatibility with previous API versions */
- typedef struct {
- unsigned stableDst; /* pledges that last 64KB decompressed data will remain available unmodified between invocations.
- * This optimization skips storage operations in tmp buffers. */
- unsigned skipChecksums; /* disable checksum calculation and verification, even when one is present in frame, to save CPU time.
- * Setting this option to 1 once disables all checksums for the rest of the frame. */
- unsigned reserved1; /* must be set to zero for forward compatibility */
- unsigned reserved0; /* idem */
- } LZ4F_decompressOptions_t;
- /* Resource management */
- /*! LZ4F_createDecompressionContext() :
- * Create an LZ4F_dctx object, to track all decompression operations.
- * @version provided MUST be LZ4F_VERSION.
- * @dctxPtr MUST be valid.
- * The function fills @dctxPtr with the value of a pointer to an allocated and initialized LZ4F_dctx object.
- * The @return is an errorCode, which can be tested using LZ4F_isError().
- * dctx memory can be released using LZ4F_freeDecompressionContext();
- * Result of LZ4F_freeDecompressionContext() indicates current state of decompressionContext when being released.
- * That is, it should be == 0 if decompression has been completed fully and correctly.
- */
- LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
- LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
- /*-***********************************
- * Streaming decompression functions
- *************************************/
- #define LZ4F_MAGICNUMBER 0x184D2204U
- #define LZ4F_MAGIC_SKIPPABLE_START 0x184D2A50U
- #define LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH 5
- /*! LZ4F_headerSize() : v1.9.0+
- * Provide the header size of a frame starting at `src`.
- * `srcSize` must be >= LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH,
- * which is enough to decode the header length.
- * @return : size of frame header
- * or an error code, which can be tested using LZ4F_isError()
- * note : Frame header size is variable, but is guaranteed to be
- * >= LZ4F_HEADER_SIZE_MIN bytes, and <= LZ4F_HEADER_SIZE_MAX bytes.
- */
- LZ4FLIB_API size_t LZ4F_headerSize(const void* src, size_t srcSize);
- /*! LZ4F_getFrameInfo() :
- * This function extracts frame parameters (max blockSize, dictID, etc.).
- * Its usage is optional: user can also invoke LZ4F_decompress() directly.
- *
- * Extracted information will fill an existing LZ4F_frameInfo_t structure.
- * This can be useful for allocation and dictionary identification purposes.
- *
- * LZ4F_getFrameInfo() can work in the following situations :
- *
- * 1) At the beginning of a new frame, before any invocation of LZ4F_decompress().
- * It will decode header from `srcBuffer`,
- * consuming the header and starting the decoding process.
- *
- * Input size must be large enough to contain the full frame header.
- * Frame header size can be known beforehand by LZ4F_headerSize().
- * Frame header size is variable, but is guaranteed to be >= LZ4F_HEADER_SIZE_MIN bytes,
- * and not more than <= LZ4F_HEADER_SIZE_MAX bytes.
- * Hence, blindly providing LZ4F_HEADER_SIZE_MAX bytes or more will always work.
- * It's allowed to provide more input data than the header size,
- * LZ4F_getFrameInfo() will only consume the header.
- *
- * If input size is not large enough,
- * aka if it's smaller than header size,
- * function will fail and return an error code.
- *
- * 2) After decoding has been started,
- * it's possible to invoke LZ4F_getFrameInfo() anytime
- * to extract already decoded frame parameters stored within dctx.
- *
- * Note that, if decoding has barely started,
- * and not yet read enough information to decode the header,
- * LZ4F_getFrameInfo() will fail.
- *
- * The number of bytes consumed from srcBuffer will be updated in *srcSizePtr (necessarily <= original value).
- * LZ4F_getFrameInfo() only consumes bytes when decoding has not yet started,
- * and when decoding the header has been successful.
- * Decompression must then resume from (srcBuffer + *srcSizePtr).
- *
- * @return : a hint about how many srcSize bytes LZ4F_decompress() expects for next call,
- * or an error code which can be tested using LZ4F_isError().
- * note 1 : in case of error, dctx is not modified. Decoding operation can resume from beginning safely.
- * note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
- */
- LZ4FLIB_API size_t
- LZ4F_getFrameInfo(LZ4F_dctx* dctx,
- LZ4F_frameInfo_t* frameInfoPtr,
- const void* srcBuffer, size_t* srcSizePtr);
- /*! LZ4F_decompress() :
- * Call this function repetitively to regenerate data compressed in `srcBuffer`.
- *
- * The function requires a valid dctx state.
- * It will read up to *srcSizePtr bytes from srcBuffer,
- * and decompress data into dstBuffer, of capacity *dstSizePtr.
- *
- * The nb of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
- * The nb of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
- *
- * The function does not necessarily read all input bytes, so always check value in *srcSizePtr.
- * Unconsumed source data must be presented again in subsequent invocations.
- *
- * `dstBuffer` can freely change between each consecutive function invocation.
- * `dstBuffer` content will be overwritten.
- *
- * @return : an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
- * Schematically, it's the size of the current (or remaining) compressed block + header of next block.
- * Respecting the hint provides some small speed benefit, because it skips intermediate buffers.
- * This is just a hint though, it's always possible to provide any srcSize.
- *
- * When a frame is fully decoded, @return will be 0 (no more data expected).
- * When provided with more bytes than necessary to decode a frame,
- * LZ4F_decompress() will stop reading exactly at end of current frame, and @return 0.
- *
- * If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
- * After a decompression error, the `dctx` context is not resumable.
- * Use LZ4F_resetDecompressionContext() to return to clean state.
- *
- * After a frame is fully decoded, dctx can be used again to decompress another frame.
- */
- LZ4FLIB_API size_t
- LZ4F_decompress(LZ4F_dctx* dctx,
- void* dstBuffer, size_t* dstSizePtr,
- const void* srcBuffer, size_t* srcSizePtr,
- const LZ4F_decompressOptions_t* dOptPtr);
- /*! LZ4F_resetDecompressionContext() : added in v1.8.0
- * In case of an error, the context is left in "undefined" state.
- * In which case, it's necessary to reset it, before re-using it.
- * This method can also be used to abruptly stop any unfinished decompression,
- * and start a new one using same context resources. */
- LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx); /* always successful */
- #if defined (__cplusplus)
- }
- #endif
- #endif /* LZ4F_H_09782039843 */
- #if defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843)
- #define LZ4F_H_STATIC_09782039843
- #if defined (__cplusplus)
- extern "C" {
- #endif
- /* These declarations are not stable and may change in the future.
- * They are therefore only safe to depend on
- * when the caller is statically linked against the library.
- * To access their declarations, define LZ4F_STATIC_LINKING_ONLY.
- *
- * By default, these symbols aren't published into shared/dynamic libraries.
- * You can override this behavior and force them to be published
- * by defining LZ4F_PUBLISH_STATIC_FUNCTIONS.
- * Use at your own risk.
- */
- #ifdef LZ4F_PUBLISH_STATIC_FUNCTIONS
- # define LZ4FLIB_STATIC_API LZ4FLIB_API
- #else
- # define LZ4FLIB_STATIC_API
- #endif
- /* --- Error List --- */
- #define LZ4F_LIST_ERRORS(ITEM) \
- ITEM(OK_NoError) \
- ITEM(ERROR_GENERIC) \
- ITEM(ERROR_maxBlockSize_invalid) \
- ITEM(ERROR_blockMode_invalid) \
- ITEM(ERROR_contentChecksumFlag_invalid) \
- ITEM(ERROR_compressionLevel_invalid) \
- ITEM(ERROR_headerVersion_wrong) \
- ITEM(ERROR_blockChecksum_invalid) \
- ITEM(ERROR_reservedFlag_set) \
- ITEM(ERROR_allocation_failed) \
- ITEM(ERROR_srcSize_tooLarge) \
- ITEM(ERROR_dstMaxSize_tooSmall) \
- ITEM(ERROR_frameHeader_incomplete) \
- ITEM(ERROR_frameType_unknown) \
- ITEM(ERROR_frameSize_wrong) \
- ITEM(ERROR_srcPtr_wrong) \
- ITEM(ERROR_decompressionFailed) \
- ITEM(ERROR_headerChecksum_invalid) \
- ITEM(ERROR_contentChecksum_invalid) \
- ITEM(ERROR_frameDecoding_alreadyStarted) \
- ITEM(ERROR_compressionState_uninitialized) \
- ITEM(ERROR_parameter_null) \
- ITEM(ERROR_maxCode)
- #define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
- /* enum list is exposed, to handle specific errors */
- typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM)
- _LZ4F_dummy_error_enum_for_c89_never_used } LZ4F_errorCodes;
- LZ4FLIB_STATIC_API LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
- /*! LZ4F_getBlockSize() :
- * Return, in scalar format (size_t),
- * the maximum block size associated with blockSizeID.
- **/
- LZ4FLIB_STATIC_API size_t LZ4F_getBlockSize(LZ4F_blockSizeID_t blockSizeID);
- /*! LZ4F_uncompressedUpdate() :
- * LZ4F_uncompressedUpdate() can be called repetitively to add as much data uncompressed data as necessary.
- * Important rule: dstCapacity MUST be large enough to store the entire source buffer as
- * no compression is done for this operation
- * If this condition is not respected, LZ4F_uncompressedUpdate() will fail (result is an errorCode).
- * After an error, the state is left in a UB state, and must be re-initialized or freed.
- * If previously a compressed block was written, buffered data is flushed
- * before appending uncompressed data is continued.
- * This is only supported when LZ4F_blockIndependent is used
- * `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
- * @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
- * or an error code if it fails (which can be tested using LZ4F_isError())
- */
- LZ4FLIB_STATIC_API size_t
- LZ4F_uncompressedUpdate(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const void* srcBuffer, size_t srcSize,
- const LZ4F_compressOptions_t* cOptPtr);
- /**********************************
- * Bulk processing dictionary API
- *********************************/
- /* A Dictionary is useful for the compression of small messages (KB range).
- * It dramatically improves compression efficiency.
- *
- * LZ4 can ingest any input as dictionary, though only the last 64 KB are useful.
- * Best results are generally achieved by using Zstandard's Dictionary Builder
- * to generate a high-quality dictionary from a set of samples.
- *
- * Loading a dictionary has a cost, since it involves construction of tables.
- * The Bulk processing dictionary API makes it possible to share this cost
- * over an arbitrary number of compression jobs, even concurrently,
- * markedly improving compression latency for these cases.
- *
- * The same dictionary will have to be used on the decompression side
- * for decoding to be successful.
- * To help identify the correct dictionary at decoding stage,
- * the frame header allows optional embedding of a dictID field.
- */
- typedef struct LZ4F_CDict_s LZ4F_CDict;
- /*! LZ4_createCDict() :
- * When compressing multiple messages / blocks using the same dictionary, it's recommended to load it just once.
- * LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
- * LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
- * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
- LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
- LZ4FLIB_STATIC_API void LZ4F_freeCDict(LZ4F_CDict* CDict);
- /*! LZ4_compressFrame_usingCDict() :
- * Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
- * cctx must point to a context created by LZ4F_createCompressionContext().
- * If cdict==NULL, compress without a dictionary.
- * dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
- * If this condition is not respected, function will fail (@return an errorCode).
- * The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
- * but it's not recommended, as it's the only way to provide dictID in the frame header.
- * @return : number of bytes written into dstBuffer.
- * or an error code if it fails (can be tested using LZ4F_isError()) */
- LZ4FLIB_STATIC_API size_t
- LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const LZ4F_CDict* cdict,
- const LZ4F_preferences_t* preferencesPtr);
- /*! LZ4F_compressBegin_usingCDict() :
- * Inits streaming dictionary compression, and writes the frame header into dstBuffer.
- * dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
- * `prefsPtr` is optional : you may provide NULL as argument,
- * however, it's the only way to provide dictID in the frame header.
- * @return : number of bytes written into dstBuffer for the header,
- * or an error code (which can be tested using LZ4F_isError()) */
- LZ4FLIB_STATIC_API size_t
- LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const LZ4F_CDict* cdict,
- const LZ4F_preferences_t* prefsPtr);
- /*! LZ4F_decompress_usingDict() :
- * Same as LZ4F_decompress(), using a predefined dictionary.
- * Dictionary is used "in place", without any preprocessing.
- ** It must remain accessible throughout the entire frame decoding. */
- LZ4FLIB_STATIC_API size_t
- LZ4F_decompress_usingDict(LZ4F_dctx* dctxPtr,
- void* dstBuffer, size_t* dstSizePtr,
- const void* srcBuffer, size_t* srcSizePtr,
- const void* dict, size_t dictSize,
- const LZ4F_decompressOptions_t* decompressOptionsPtr);
- /*! Custom memory allocation :
- * These prototypes make it possible to pass custom allocation/free functions.
- * LZ4F_customMem is provided at state creation time, using LZ4F_create*_advanced() listed below.
- * All allocation/free operations will be completed using these custom variants instead of regular <stdlib.h> ones.
- */
- typedef void* (*LZ4F_AllocFunction) (void* opaqueState, size_t size);
- typedef void* (*LZ4F_CallocFunction) (void* opaqueState, size_t size);
- typedef void (*LZ4F_FreeFunction) (void* opaqueState, void* address);
- typedef struct {
- LZ4F_AllocFunction customAlloc;
- LZ4F_CallocFunction customCalloc; /* optional; when not defined, uses customAlloc + memset */
- LZ4F_FreeFunction customFree;
- void* opaqueState;
- } LZ4F_CustomMem;
- static
- #ifdef __GNUC__
- __attribute__((__unused__))
- #endif
- LZ4F_CustomMem const LZ4F_defaultCMem = { NULL, NULL, NULL, NULL }; /**< this constant defers to stdlib's functions */
- LZ4FLIB_STATIC_API LZ4F_cctx* LZ4F_createCompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version);
- LZ4FLIB_STATIC_API LZ4F_dctx* LZ4F_createDecompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version);
- LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict_advanced(LZ4F_CustomMem customMem, const void* dictBuffer, size_t dictSize);
- #if defined (__cplusplus)
- }
- #endif
- #endif /* defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843) */
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