| /* |
| LZ4 auto-framing library |
| Header File |
| Copyright (C) 2011-2017, 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 constant 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 (doc/lz4_Frame_format.md). |
| lz4frame.h provides frame compression functions that take care |
| of encoding standard metadata alongside LZ4-compressed blocks. |
| */ |
| |
| /*-*************************************************************** |
| * 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 used with LZ4F_compressUpdate() _if no flush() operation_ is 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 previous API version */ |
| |
| 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 be used in all compression operations. |
| * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version. |
| * The version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL. |
| * The function will provide a pointer to a fully allocated LZ4F_cctx object. |
| * If @return != zero, there was an error during context creation. |
| * Object can release its memory using LZ4F_freeCompressionContext(); |
| */ |
| 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 paramaters */ |
| #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). |
| * LZ4F_compressUpdate() doesn't guarantee error recovery. |
| * When an error occurs, compression context must be freed or resized. |
| * `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. This optimization skips storage operations in tmp buffers. */ |
| unsigned reserved[3]; /* must be set to zero for forward compatibility */ |
| } LZ4F_decompressOptions_t; |
| |
| |
| /* Resource management */ |
| |
| /*! LZ4F_createDecompressionContext() : |
| * Create an LZ4F_dctx object, to track all decompression operations. |
| * The version provided MUST be LZ4F_VERSION. |
| * The function provides a pointer to an allocated and initialized LZ4F_dctx object. |
| * The result 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_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 call 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_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); |
| |
| LZ4FLIB_STATIC_API size_t LZ4F_getBlockSize(unsigned); |
| |
| /********************************** |
| * 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); |
| |
| #if defined (__cplusplus) |
| } |
| #endif |
| |
| #endif /* defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843) */ |