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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) */