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Diffstat (limited to 'mfbt/lz4/lz4frame.h')
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diff --git a/mfbt/lz4/lz4frame.h b/mfbt/lz4/lz4frame.h new file mode 100644 index 0000000000..1bdf6c4fcb --- /dev/null +++ b/mfbt/lz4/lz4frame.h @@ -0,0 +1,692 @@ +/* + 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) */ |