--- /dev/null
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+#ifndef ZSTD_H_235446
+#define ZSTD_H_235446
+
+/* ====== Dependencies ======*/
+#include <limits.h> /* INT_MAX */
+#include <stddef.h> /* size_t */
+
+
+/* ===== ZSTDLIB_API : control library symbols visibility ===== */
+#ifndef ZSTDLIB_VISIBLE
+ /* Backwards compatibility with old macro name */
+# ifdef ZSTDLIB_VISIBILITY
+# define ZSTDLIB_VISIBLE ZSTDLIB_VISIBILITY
+# elif defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
+# define ZSTDLIB_VISIBLE __attribute__ ((visibility ("default")))
+# else
+# define ZSTDLIB_VISIBLE
+# endif
+#endif
+
+#ifndef ZSTDLIB_HIDDEN
+# if defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
+# define ZSTDLIB_HIDDEN __attribute__ ((visibility ("hidden")))
+# else
+# define ZSTDLIB_HIDDEN
+# endif
+#endif
+
+#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
+# define ZSTDLIB_API __declspec(dllexport) ZSTDLIB_VISIBLE
+#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
+# define ZSTDLIB_API __declspec(dllimport) ZSTDLIB_VISIBLE /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
+#else
+# define ZSTDLIB_API ZSTDLIB_VISIBLE
+#endif
+
+/* Deprecation warnings :
+ * Should these warnings be a problem, it is generally possible to disable them,
+ * typically with -Wno-deprecated-declarations for gcc or _CRT_SECURE_NO_WARNINGS in Visual.
+ * Otherwise, it's also possible to define ZSTD_DISABLE_DEPRECATE_WARNINGS.
+ */
+#ifdef ZSTD_DISABLE_DEPRECATE_WARNINGS
+# define ZSTD_DEPRECATED(message) /* disable deprecation warnings */
+#else
+# if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
+# define ZSTD_DEPRECATED(message) [[deprecated(message)]]
+# elif (defined(GNUC) && (GNUC > 4 || (GNUC == 4 && GNUC_MINOR >= 5))) || defined(__clang__)
+# define ZSTD_DEPRECATED(message) __attribute__((deprecated(message)))
+# elif defined(__GNUC__) && (__GNUC__ >= 3)
+# define ZSTD_DEPRECATED(message) __attribute__((deprecated))
+# elif defined(_MSC_VER)
+# define ZSTD_DEPRECATED(message) __declspec(deprecated(message))
+# else
+# pragma message("WARNING: You need to implement ZSTD_DEPRECATED for this compiler")
+# define ZSTD_DEPRECATED(message)
+# endif
+#endif /* ZSTD_DISABLE_DEPRECATE_WARNINGS */
+
+
+/*******************************************************************************
+ Introduction
+
+ zstd, short for Zstandard, is a fast lossless compression algorithm, targeting
+ real-time compression scenarios at zlib-level and better compression ratios.
+ The zstd compression library provides in-memory compression and decompression
+ functions.
+
+ The library supports regular compression levels from 1 up to ZSTD_maxCLevel(),
+ which is currently 22. Levels >= 20, labeled `--ultra`, should be used with
+ caution, as they require more memory. The library also offers negative
+ compression levels, which extend the range of speed vs. ratio preferences.
+ The lower the level, the faster the speed (at the cost of compression).
+
+ Compression can be done in:
+ - a single step (described as Simple API)
+ - a single step, reusing a context (described as Explicit context)
+ - unbounded multiple steps (described as Streaming compression)
+
+ The compression ratio achievable on small data can be highly improved using
+ a dictionary. Dictionary compression can be performed in:
+ - a single step (described as Simple dictionary API)
+ - a single step, reusing a dictionary (described as Bulk-processing
+ dictionary API)
+
+ Advanced experimental functions can be accessed using
+ `#define ZSTD_STATIC_LINKING_ONLY` before including zstd.h.
+
+ Advanced experimental APIs should never be used with a dynamically-linked
+ library. They are not "stable"; their definitions or signatures may change in
+ the future. Only static linking is allowed.
+*******************************************************************************/
+
+/*------ Version ------*/
+#define ZSTD_VERSION_MAJOR 1
+#define ZSTD_VERSION_MINOR 5
+#define ZSTD_VERSION_RELEASE 5
+#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
+
+/*! ZSTD_versionNumber() :
+ * Return runtime library version, the value is (MAJOR*100*100 + MINOR*100 + RELEASE). */
+ZSTDLIB_API unsigned ZSTD_versionNumber(void);
+
+#define ZSTD_LIB_VERSION ZSTD_VERSION_MAJOR.ZSTD_VERSION_MINOR.ZSTD_VERSION_RELEASE
+#define ZSTD_QUOTE(str) #str
+#define ZSTD_EXPAND_AND_QUOTE(str) ZSTD_QUOTE(str)
+#define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION)
+
+/*! ZSTD_versionString() :
+ * Return runtime library version, like "1.4.5". Requires v1.3.0+. */
+ZSTDLIB_API const char* ZSTD_versionString(void);
+
+/* *************************************
+ * Default constant
+ ***************************************/
+#ifndef ZSTD_CLEVEL_DEFAULT
+# define ZSTD_CLEVEL_DEFAULT 3
+#endif
+
+/* *************************************
+ * Constants
+ ***************************************/
+
+/* All magic numbers are supposed read/written to/from files/memory using little-endian convention */
+#define ZSTD_MAGICNUMBER 0xFD2FB528 /* valid since v0.8.0 */
+#define ZSTD_MAGIC_DICTIONARY 0xEC30A437 /* valid since v0.7.0 */
+#define ZSTD_MAGIC_SKIPPABLE_START 0x184D2A50 /* all 16 values, from 0x184D2A50 to 0x184D2A5F, signal the beginning of a skippable frame */
+#define ZSTD_MAGIC_SKIPPABLE_MASK 0xFFFFFFF0
+
+#define ZSTD_BLOCKSIZELOG_MAX 17
+#define ZSTD_BLOCKSIZE_MAX (1<<ZSTD_BLOCKSIZELOG_MAX)
+
+
+/***************************************
+* Simple API
+***************************************/
+/*! ZSTD_compress() :
+ * Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
+ * NOTE: Providing `dstCapacity >= ZSTD_compressBound(srcSize)` guarantees that zstd will have
+ * enough space to successfully compress the data.
+ * @return : compressed size written into `dst` (<= `dstCapacity),
+ * or an error code if it fails (which can be tested using ZSTD_isError()). */
+ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ int compressionLevel);
+
+/*! ZSTD_decompress() :
+ * `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
+ * `dstCapacity` is an upper bound of originalSize to regenerate.
+ * If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
+ * @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
+ * or an errorCode if it fails (which can be tested using ZSTD_isError()). */
+ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,
+ const void* src, size_t compressedSize);
+
+/*! ZSTD_getFrameContentSize() : requires v1.3.0+
+ * `src` should point to the start of a ZSTD encoded frame.
+ * `srcSize` must be at least as large as the frame header.
+ * hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
+ * @return : - decompressed size of `src` frame content, if known
+ * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
+ * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
+ * note 1 : a 0 return value means the frame is valid but "empty".
+ * note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
+ * When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * Optionally, application can rely on some implicit limit,
+ * as ZSTD_decompress() only needs an upper bound of decompressed size.
+ * (For example, data could be necessarily cut into blocks <= 16 KB).
+ * note 3 : decompressed size is always present when compression is completed using single-pass functions,
+ * such as ZSTD_compress(), ZSTD_compressCCtx() ZSTD_compress_usingDict() or ZSTD_compress_usingCDict().
+ * note 4 : decompressed size can be very large (64-bits value),
+ * potentially larger than what local system can handle as a single memory segment.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
+ * Always ensure return value fits within application's authorized limits.
+ * Each application can set its own limits.
+ * note 6 : This function replaces ZSTD_getDecompressedSize() */
+#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
+#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
+ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
+
+/*! ZSTD_getDecompressedSize() :
+ * NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
+ * Both functions work the same way, but ZSTD_getDecompressedSize() blends
+ * "empty", "unknown" and "error" results to the same return value (0),
+ * while ZSTD_getFrameContentSize() gives them separate return values.
+ * @return : decompressed size of `src` frame content _if known and not empty_, 0 otherwise. */
+ZSTD_DEPRECATED("Replaced by ZSTD_getFrameContentSize")
+ZSTDLIB_API
+unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
+
+/*! ZSTD_findFrameCompressedSize() : Requires v1.4.0+
+ * `src` should point to the start of a ZSTD frame or skippable frame.
+ * `srcSize` must be >= first frame size
+ * @return : the compressed size of the first frame starting at `src`,
+ * suitable to pass as `srcSize` to `ZSTD_decompress` or similar,
+ * or an error code if input is invalid */
+ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
+
+
+/*====== Helper functions ======*/
+/* ZSTD_compressBound() :
+ * maximum compressed size in worst case single-pass scenario.
+ * When invoking `ZSTD_compress()` or any other one-pass compression function,
+ * it's recommended to provide @dstCapacity >= ZSTD_compressBound(srcSize)
+ * as it eliminates one potential failure scenario,
+ * aka not enough room in dst buffer to write the compressed frame.
+ * Note : ZSTD_compressBound() itself can fail, if @srcSize > ZSTD_MAX_INPUT_SIZE .
+ * In which case, ZSTD_compressBound() will return an error code
+ * which can be tested using ZSTD_isError().
+ *
+ * ZSTD_COMPRESSBOUND() :
+ * same as ZSTD_compressBound(), but as a macro.
+ * It can be used to produce constants, which can be useful for static allocation,
+ * for example to size a static array on stack.
+ * Will produce constant value 0 if srcSize too large.
+ */
+#define ZSTD_MAX_INPUT_SIZE ((sizeof(size_t)==8) ? 0xFF00FF00FF00FF00LLU : 0xFF00FF00U)
+#define ZSTD_COMPRESSBOUND(srcSize) (((size_t)(srcSize) >= ZSTD_MAX_INPUT_SIZE) ? 0 : (srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0)) /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */
+ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */
+/* ZSTD_isError() :
+ * Most ZSTD_* functions returning a size_t value can be tested for error,
+ * using ZSTD_isError().
+ * @return 1 if error, 0 otherwise
+ */
+ZSTDLIB_API unsigned ZSTD_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
+ZSTDLIB_API const char* ZSTD_getErrorName(size_t code); /*!< provides readable string from an error code */
+ZSTDLIB_API int ZSTD_minCLevel(void); /*!< minimum negative compression level allowed, requires v1.4.0+ */
+ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
+ZSTDLIB_API int ZSTD_defaultCLevel(void); /*!< default compression level, specified by ZSTD_CLEVEL_DEFAULT, requires v1.5.0+ */
+
+
+/***************************************
+* Explicit context
+***************************************/
+/*= Compression context
+ * When compressing many times,
+ * it is recommended to allocate a context just once,
+ * and re-use it for each successive compression operation.
+ * This will make workload friendlier for system's memory.
+ * Note : re-using context is just a speed / resource optimization.
+ * It doesn't change the compression ratio, which remains identical.
+ * Note 2 : In multi-threaded environments,
+ * use one different context per thread for parallel execution.
+ */
+typedef struct ZSTD_CCtx_s ZSTD_CCtx;
+ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx(void);
+ZSTDLIB_API size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx); /* accept NULL pointer */
+
+/*! ZSTD_compressCCtx() :
+ * Same as ZSTD_compress(), using an explicit ZSTD_CCtx.
+ * Important : in order to behave similarly to `ZSTD_compress()`,
+ * this function compresses at requested compression level,
+ * __ignoring any other parameter__ .
+ * If any advanced parameter was set using the advanced API,
+ * they will all be reset. Only `compressionLevel` remains.
+ */
+ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ int compressionLevel);
+
+/*= Decompression context
+ * When decompressing many times,
+ * it is recommended to allocate a context only once,
+ * and re-use it for each successive compression operation.
+ * This will make workload friendlier for system's memory.
+ * Use one context per thread for parallel execution. */
+typedef struct ZSTD_DCtx_s ZSTD_DCtx;
+ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx(void);
+ZSTDLIB_API size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); /* accept NULL pointer */
+
+/*! ZSTD_decompressDCtx() :
+ * Same as ZSTD_decompress(),
+ * requires an allocated ZSTD_DCtx.
+ * Compatible with sticky parameters.
+ */
+ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize);
+
+
+/*********************************************
+* Advanced compression API (Requires v1.4.0+)
+**********************************************/
+
+/* API design :
+ * Parameters are pushed one by one into an existing context,
+ * using ZSTD_CCtx_set*() functions.
+ * Pushed parameters are sticky : they are valid for next compressed frame, and any subsequent frame.
+ * "sticky" parameters are applicable to `ZSTD_compress2()` and `ZSTD_compressStream*()` !
+ * __They do not apply to "simple" one-shot variants such as ZSTD_compressCCtx()__ .
+ *
+ * It's possible to reset all parameters to "default" using ZSTD_CCtx_reset().
+ *
+ * This API supersedes all other "advanced" API entry points in the experimental section.
+ * In the future, we expect to remove from experimental API entry points which are redundant with this API.
+ */
+
+
+/* Compression strategies, listed from fastest to strongest */
+typedef enum { ZSTD_fast=1,
+ ZSTD_dfast=2,
+ ZSTD_greedy=3,
+ ZSTD_lazy=4,
+ ZSTD_lazy2=5,
+ ZSTD_btlazy2=6,
+ ZSTD_btopt=7,
+ ZSTD_btultra=8,
+ ZSTD_btultra2=9
+ /* note : new strategies _might_ be added in the future.
+ Only the order (from fast to strong) is guaranteed */
+} ZSTD_strategy;
+
+typedef enum {
+
+ /* compression parameters
+ * Note: When compressing with a ZSTD_CDict these parameters are superseded
+ * by the parameters used to construct the ZSTD_CDict.
+ * See ZSTD_CCtx_refCDict() for more info (superseded-by-cdict). */
+ ZSTD_c_compressionLevel=100, /* Set compression parameters according to pre-defined cLevel table.
+ * Note that exact compression parameters are dynamically determined,
+ * depending on both compression level and srcSize (when known).
+ * Default level is ZSTD_CLEVEL_DEFAULT==3.
+ * Special: value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
+ * Note 1 : it's possible to pass a negative compression level.
+ * Note 2 : setting a level does not automatically set all other compression parameters
+ * to default. Setting this will however eventually dynamically impact the compression
+ * parameters which have not been manually set. The manually set
+ * ones will 'stick'. */
+ /* Advanced compression parameters :
+ * It's possible to pin down compression parameters to some specific values.
+ * In which case, these values are no longer dynamically selected by the compressor */
+ ZSTD_c_windowLog=101, /* Maximum allowed back-reference distance, expressed as power of 2.
+ * This will set a memory budget for streaming decompression,
+ * with larger values requiring more memory
+ * and typically compressing more.
+ * Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
+ * Special: value 0 means "use default windowLog".
+ * Note: Using a windowLog greater than ZSTD_WINDOWLOG_LIMIT_DEFAULT
+ * requires explicitly allowing such size at streaming decompression stage. */
+ ZSTD_c_hashLog=102, /* Size of the initial probe table, as a power of 2.
+ * Resulting memory usage is (1 << (hashLog+2)).
+ * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
+ * Larger tables improve compression ratio of strategies <= dFast,
+ * and improve speed of strategies > dFast.
+ * Special: value 0 means "use default hashLog". */
+ ZSTD_c_chainLog=103, /* Size of the multi-probe search table, as a power of 2.
+ * Resulting memory usage is (1 << (chainLog+2)).
+ * Must be clamped between ZSTD_CHAINLOG_MIN and ZSTD_CHAINLOG_MAX.
+ * Larger tables result in better and slower compression.
+ * This parameter is useless for "fast" strategy.
+ * It's still useful when using "dfast" strategy,
+ * in which case it defines a secondary probe table.
+ * Special: value 0 means "use default chainLog". */
+ ZSTD_c_searchLog=104, /* Number of search attempts, as a power of 2.
+ * More attempts result in better and slower compression.
+ * This parameter is useless for "fast" and "dFast" strategies.
+ * Special: value 0 means "use default searchLog". */
+ ZSTD_c_minMatch=105, /* Minimum size of searched matches.
+ * Note that Zstandard can still find matches of smaller size,
+ * it just tweaks its search algorithm to look for this size and larger.
+ * Larger values increase compression and decompression speed, but decrease ratio.
+ * Must be clamped between ZSTD_MINMATCH_MIN and ZSTD_MINMATCH_MAX.
+ * Note that currently, for all strategies < btopt, effective minimum is 4.
+ * , for all strategies > fast, effective maximum is 6.
+ * Special: value 0 means "use default minMatchLength". */
+ ZSTD_c_targetLength=106, /* Impact of this field depends on strategy.
+ * For strategies btopt, btultra & btultra2:
+ * Length of Match considered "good enough" to stop search.
+ * Larger values make compression stronger, and slower.
+ * For strategy fast:
+ * Distance between match sampling.
+ * Larger values make compression faster, and weaker.
+ * Special: value 0 means "use default targetLength". */
+ ZSTD_c_strategy=107, /* See ZSTD_strategy enum definition.
+ * The higher the value of selected strategy, the more complex it is,
+ * resulting in stronger and slower compression.
+ * Special: value 0 means "use default strategy". */
+ /* LDM mode parameters */
+ ZSTD_c_enableLongDistanceMatching=160, /* Enable long distance matching.
+ * This parameter is designed to improve compression ratio
+ * for large inputs, by finding large matches at long distance.
+ * It increases memory usage and window size.
+ * Note: enabling this parameter increases default ZSTD_c_windowLog to 128 MB
+ * except when expressly set to a different value.
+ * Note: will be enabled by default if ZSTD_c_windowLog >= 128 MB and
+ * compression strategy >= ZSTD_btopt (== compression level 16+) */
+ ZSTD_c_ldmHashLog=161, /* Size of the table for long distance matching, as a power of 2.
+ * Larger values increase memory usage and compression ratio,
+ * but decrease compression speed.
+ * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
+ * default: windowlog - 7.
+ * Special: value 0 means "automatically determine hashlog". */
+ ZSTD_c_ldmMinMatch=162, /* Minimum match size for long distance matcher.
+ * Larger/too small values usually decrease compression ratio.
+ * Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
+ * Special: value 0 means "use default value" (default: 64). */
+ ZSTD_c_ldmBucketSizeLog=163, /* Log size of each bucket in the LDM hash table for collision resolution.
+ * Larger values improve collision resolution but decrease compression speed.
+ * The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX.
+ * Special: value 0 means "use default value" (default: 3). */
+ ZSTD_c_ldmHashRateLog=164, /* Frequency of inserting/looking up entries into the LDM hash table.
+ * Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
+ * Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
+ * Larger values improve compression speed.
+ * Deviating far from default value will likely result in a compression ratio decrease.
+ * Special: value 0 means "automatically determine hashRateLog". */
+
+ /* frame parameters */
+ ZSTD_c_contentSizeFlag=200, /* Content size will be written into frame header _whenever known_ (default:1)
+ * Content size must be known at the beginning of compression.
+ * This is automatically the case when using ZSTD_compress2(),
+ * For streaming scenarios, content size must be provided with ZSTD_CCtx_setPledgedSrcSize() */
+ ZSTD_c_checksumFlag=201, /* A 32-bits checksum of content is written at end of frame (default:0) */
+ ZSTD_c_dictIDFlag=202, /* When applicable, dictionary's ID is written into frame header (default:1) */
+
+ /* multi-threading parameters */
+ /* These parameters are only active if multi-threading is enabled (compiled with build macro ZSTD_MULTITHREAD).
+ * Otherwise, trying to set any other value than default (0) will be a no-op and return an error.
+ * In a situation where it's unknown if the linked library supports multi-threading or not,
+ * setting ZSTD_c_nbWorkers to any value >= 1 and consulting the return value provides a quick way to check this property.
+ */
+ ZSTD_c_nbWorkers=400, /* Select how many threads will be spawned to compress in parallel.
+ * When nbWorkers >= 1, triggers asynchronous mode when invoking ZSTD_compressStream*() :
+ * ZSTD_compressStream*() consumes input and flush output if possible, but immediately gives back control to caller,
+ * while compression is performed in parallel, within worker thread(s).
+ * (note : a strong exception to this rule is when first invocation of ZSTD_compressStream2() sets ZSTD_e_end :
+ * in which case, ZSTD_compressStream2() delegates to ZSTD_compress2(), which is always a blocking call).
+ * More workers improve speed, but also increase memory usage.
+ * Default value is `0`, aka "single-threaded mode" : no worker is spawned,
+ * compression is performed inside Caller's thread, and all invocations are blocking */
+ ZSTD_c_jobSize=401, /* Size of a compression job. This value is enforced only when nbWorkers >= 1.
+ * Each compression job is completed in parallel, so this value can indirectly impact the nb of active threads.
+ * 0 means default, which is dynamically determined based on compression parameters.
+ * Job size must be a minimum of overlap size, or ZSTDMT_JOBSIZE_MIN (= 512 KB), whichever is largest.
+ * The minimum size is automatically and transparently enforced. */
+ ZSTD_c_overlapLog=402, /* Control the overlap size, as a fraction of window size.
+ * The overlap size is an amount of data reloaded from previous job at the beginning of a new job.
+ * It helps preserve compression ratio, while each job is compressed in parallel.
+ * This value is enforced only when nbWorkers >= 1.
+ * Larger values increase compression ratio, but decrease speed.
+ * Possible values range from 0 to 9 :
+ * - 0 means "default" : value will be determined by the library, depending on strategy
+ * - 1 means "no overlap"
+ * - 9 means "full overlap", using a full window size.
+ * Each intermediate rank increases/decreases load size by a factor 2 :
+ * 9: full window; 8: w/2; 7: w/4; 6: w/8; 5:w/16; 4: w/32; 3:w/64; 2:w/128; 1:no overlap; 0:default
+ * default value varies between 6 and 9, depending on strategy */
+
+ /* note : additional experimental parameters are also available
+ * within the experimental section of the API.
+ * At the time of this writing, they include :
+ * ZSTD_c_rsyncable
+ * ZSTD_c_format
+ * ZSTD_c_forceMaxWindow
+ * ZSTD_c_forceAttachDict
+ * ZSTD_c_literalCompressionMode
+ * ZSTD_c_targetCBlockSize
+ * ZSTD_c_srcSizeHint
+ * ZSTD_c_enableDedicatedDictSearch
+ * ZSTD_c_stableInBuffer
+ * ZSTD_c_stableOutBuffer
+ * ZSTD_c_blockDelimiters
+ * ZSTD_c_validateSequences
+ * ZSTD_c_useBlockSplitter
+ * ZSTD_c_useRowMatchFinder
+ * ZSTD_c_prefetchCDictTables
+ * ZSTD_c_enableSeqProducerFallback
+ * ZSTD_c_maxBlockSize
+ * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
+ * note : never ever use experimentalParam? names directly;
+ * also, the enums values themselves are unstable and can still change.
+ */
+ ZSTD_c_experimentalParam1=500,
+ ZSTD_c_experimentalParam2=10,
+ ZSTD_c_experimentalParam3=1000,
+ ZSTD_c_experimentalParam4=1001,
+ ZSTD_c_experimentalParam5=1002,
+ ZSTD_c_experimentalParam6=1003,
+ ZSTD_c_experimentalParam7=1004,
+ ZSTD_c_experimentalParam8=1005,
+ ZSTD_c_experimentalParam9=1006,
+ ZSTD_c_experimentalParam10=1007,
+ ZSTD_c_experimentalParam11=1008,
+ ZSTD_c_experimentalParam12=1009,
+ ZSTD_c_experimentalParam13=1010,
+ ZSTD_c_experimentalParam14=1011,
+ ZSTD_c_experimentalParam15=1012,
+ ZSTD_c_experimentalParam16=1013,
+ ZSTD_c_experimentalParam17=1014,
+ ZSTD_c_experimentalParam18=1015,
+ ZSTD_c_experimentalParam19=1016
+} ZSTD_cParameter;
+
+typedef struct {
+ size_t error;
+ int lowerBound;
+ int upperBound;
+} ZSTD_bounds;
+
+/*! ZSTD_cParam_getBounds() :
+ * All parameters must belong to an interval with lower and upper bounds,
+ * otherwise they will either trigger an error or be automatically clamped.
+ * @return : a structure, ZSTD_bounds, which contains
+ * - an error status field, which must be tested using ZSTD_isError()
+ * - lower and upper bounds, both inclusive
+ */
+ZSTDLIB_API ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter cParam);
+
+/*! ZSTD_CCtx_setParameter() :
+ * Set one compression parameter, selected by enum ZSTD_cParameter.
+ * All parameters have valid bounds. Bounds can be queried using ZSTD_cParam_getBounds().
+ * Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
+ * Setting a parameter is generally only possible during frame initialization (before starting compression).
+ * Exception : when using multi-threading mode (nbWorkers >= 1),
+ * the following parameters can be updated _during_ compression (within same frame):
+ * => compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
+ * new parameters will be active for next job only (after a flush()).
+ * @return : an error code (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value);
+
+/*! ZSTD_CCtx_setPledgedSrcSize() :
+ * Total input data size to be compressed as a single frame.
+ * Value will be written in frame header, unless if explicitly forbidden using ZSTD_c_contentSizeFlag.
+ * This value will also be controlled at end of frame, and trigger an error if not respected.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Note 1 : pledgedSrcSize==0 actually means zero, aka an empty frame.
+ * In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
+ * ZSTD_CONTENTSIZE_UNKNOWN is default value for any new frame.
+ * Note 2 : pledgedSrcSize is only valid once, for the next frame.
+ * It's discarded at the end of the frame, and replaced by ZSTD_CONTENTSIZE_UNKNOWN.
+ * Note 3 : Whenever all input data is provided and consumed in a single round,
+ * for example with ZSTD_compress2(),
+ * or invoking immediately ZSTD_compressStream2(,,,ZSTD_e_end),
+ * this value is automatically overridden by srcSize instead.
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
+
+typedef enum {
+ ZSTD_reset_session_only = 1,
+ ZSTD_reset_parameters = 2,
+ ZSTD_reset_session_and_parameters = 3
+} ZSTD_ResetDirective;
+
+/*! ZSTD_CCtx_reset() :
+ * There are 2 different things that can be reset, independently or jointly :
+ * - The session : will stop compressing current frame, and make CCtx ready to start a new one.
+ * Useful after an error, or to interrupt any ongoing compression.
+ * Any internal data not yet flushed is cancelled.
+ * Compression parameters and dictionary remain unchanged.
+ * They will be used to compress next frame.
+ * Resetting session never fails.
+ * - The parameters : changes all parameters back to "default".
+ * This also removes any reference to any dictionary or external sequence producer.
+ * Parameters can only be changed between 2 sessions (i.e. no compression is currently ongoing)
+ * otherwise the reset fails, and function returns an error value (which can be tested using ZSTD_isError())
+ * - Both : similar to resetting the session, followed by resetting parameters.
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset);
+
+/*! ZSTD_compress2() :
+ * Behave the same as ZSTD_compressCCtx(), but compression parameters are set using the advanced API.
+ * ZSTD_compress2() always starts a new frame.
+ * Should cctx hold data from a previously unfinished frame, everything about it is forgotten.
+ * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
+ * - The function is always blocking, returns when compression is completed.
+ * NOTE: Providing `dstCapacity >= ZSTD_compressBound(srcSize)` guarantees that zstd will have
+ * enough space to successfully compress the data, though it is possible it fails for other reasons.
+ * @return : compressed size written into `dst` (<= `dstCapacity),
+ * or an error code if it fails (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_compress2( ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize);
+
+
+/***********************************************
+* Advanced decompression API (Requires v1.4.0+)
+************************************************/
+
+/* The advanced API pushes parameters one by one into an existing DCtx context.
+ * Parameters are sticky, and remain valid for all following frames
+ * using the same DCtx context.
+ * It's possible to reset parameters to default values using ZSTD_DCtx_reset().
+ * Note : This API is compatible with existing ZSTD_decompressDCtx() and ZSTD_decompressStream().
+ * Therefore, no new decompression function is necessary.
+ */
+
+typedef enum {
+
+ ZSTD_d_windowLogMax=100, /* Select a size limit (in power of 2) beyond which
+ * the streaming API will refuse to allocate memory buffer
+ * in order to protect the host from unreasonable memory requirements.
+ * This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
+ * By default, a decompression context accepts window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT).
+ * Special: value 0 means "use default maximum windowLog". */
+
+ /* note : additional experimental parameters are also available
+ * within the experimental section of the API.
+ * At the time of this writing, they include :
+ * ZSTD_d_format
+ * ZSTD_d_stableOutBuffer
+ * ZSTD_d_forceIgnoreChecksum
+ * ZSTD_d_refMultipleDDicts
+ * ZSTD_d_disableHuffmanAssembly
+ * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
+ * note : never ever use experimentalParam? names directly
+ */
+ ZSTD_d_experimentalParam1=1000,
+ ZSTD_d_experimentalParam2=1001,
+ ZSTD_d_experimentalParam3=1002,
+ ZSTD_d_experimentalParam4=1003,
+ ZSTD_d_experimentalParam5=1004
+
+} ZSTD_dParameter;
+
+/*! ZSTD_dParam_getBounds() :
+ * All parameters must belong to an interval with lower and upper bounds,
+ * otherwise they will either trigger an error or be automatically clamped.
+ * @return : a structure, ZSTD_bounds, which contains
+ * - an error status field, which must be tested using ZSTD_isError()
+ * - both lower and upper bounds, inclusive
+ */
+ZSTDLIB_API ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam);
+
+/*! ZSTD_DCtx_setParameter() :
+ * Set one compression parameter, selected by enum ZSTD_dParameter.
+ * All parameters have valid bounds. Bounds can be queried using ZSTD_dParam_getBounds().
+ * Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
+ * Setting a parameter is only possible during frame initialization (before starting decompression).
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int value);
+
+/*! ZSTD_DCtx_reset() :
+ * Return a DCtx to clean state.
+ * Session and parameters can be reset jointly or separately.
+ * Parameters can only be reset when no active frame is being decompressed.
+ * @return : 0, or an error code, which can be tested with ZSTD_isError()
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);
+
+
+/****************************
+* Streaming
+****************************/
+
+typedef struct ZSTD_inBuffer_s {
+ const void* src; /**< start of input buffer */
+ size_t size; /**< size of input buffer */
+ size_t pos; /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
+} ZSTD_inBuffer;
+
+typedef struct ZSTD_outBuffer_s {
+ void* dst; /**< start of output buffer */
+ size_t size; /**< size of output buffer */
+ size_t pos; /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
+} ZSTD_outBuffer;
+
+
+
+/*-***********************************************************************
+* Streaming compression - HowTo
+*
+* A ZSTD_CStream object is required to track streaming operation.
+* Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources.
+* ZSTD_CStream objects can be reused multiple times on consecutive compression operations.
+* It is recommended to re-use ZSTD_CStream since it will play nicer with system's memory, by re-using already allocated memory.
+*
+* For parallel execution, use one separate ZSTD_CStream per thread.
+*
+* note : since v1.3.0, ZSTD_CStream and ZSTD_CCtx are the same thing.
+*
+* Parameters are sticky : when starting a new compression on the same context,
+* it will re-use the same sticky parameters as previous compression session.
+* When in doubt, it's recommended to fully initialize the context before usage.
+* Use ZSTD_CCtx_reset() to reset the context and ZSTD_CCtx_setParameter(),
+* ZSTD_CCtx_setPledgedSrcSize(), or ZSTD_CCtx_loadDictionary() and friends to
+* set more specific parameters, the pledged source size, or load a dictionary.
+*
+* Use ZSTD_compressStream2() with ZSTD_e_continue as many times as necessary to
+* consume input stream. The function will automatically update both `pos`
+* fields within `input` and `output`.
+* Note that the function may not consume the entire input, for example, because
+* the output buffer is already full, in which case `input.pos < input.size`.
+* The caller must check if input has been entirely consumed.
+* If not, the caller must make some room to receive more compressed data,
+* and then present again remaining input data.
+* note: ZSTD_e_continue is guaranteed to make some forward progress when called,
+* but doesn't guarantee maximal forward progress. This is especially relevant
+* when compressing with multiple threads. The call won't block if it can
+* consume some input, but if it can't it will wait for some, but not all,
+* output to be flushed.
+* @return : provides a minimum amount of data remaining to be flushed from internal buffers
+* or an error code, which can be tested using ZSTD_isError().
+*
+* At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
+* using ZSTD_compressStream2() with ZSTD_e_flush. `output->pos` will be updated.
+* Note that, if `output->size` is too small, a single invocation with ZSTD_e_flush might not be enough (return code > 0).
+* In which case, make some room to receive more compressed data, and call again ZSTD_compressStream2() with ZSTD_e_flush.
+* You must continue calling ZSTD_compressStream2() with ZSTD_e_flush until it returns 0, at which point you can change the
+* operation.
+* note: ZSTD_e_flush will flush as much output as possible, meaning when compressing with multiple threads, it will
+* block until the flush is complete or the output buffer is full.
+* @return : 0 if internal buffers are entirely flushed,
+* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
+* or an error code, which can be tested using ZSTD_isError().
+*
+* Calling ZSTD_compressStream2() with ZSTD_e_end instructs to finish a frame.
+* It will perform a flush and write frame epilogue.
+* The epilogue is required for decoders to consider a frame completed.
+* flush operation is the same, and follows same rules as calling ZSTD_compressStream2() with ZSTD_e_flush.
+* You must continue calling ZSTD_compressStream2() with ZSTD_e_end until it returns 0, at which point you are free to
+* start a new frame.
+* note: ZSTD_e_end will flush as much output as possible, meaning when compressing with multiple threads, it will
+* block until the flush is complete or the output buffer is full.
+* @return : 0 if frame fully completed and fully flushed,
+* >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
+* or an error code, which can be tested using ZSTD_isError().
+*
+* *******************************************************************/
+
+typedef ZSTD_CCtx ZSTD_CStream; /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
+ /* Continue to distinguish them for compatibility with older versions <= v1.2.0 */
+/*===== ZSTD_CStream management functions =====*/
+ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
+ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs); /* accept NULL pointer */
+
+/*===== Streaming compression functions =====*/
+typedef enum {
+ ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
+ ZSTD_e_flush=1, /* flush any data provided so far,
+ * it creates (at least) one new block, that can be decoded immediately on reception;
+ * frame will continue: any future data can still reference previously compressed data, improving compression.
+ * note : multithreaded compression will block to flush as much output as possible. */
+ ZSTD_e_end=2 /* flush any remaining data _and_ close current frame.
+ * note that frame is only closed after compressed data is fully flushed (return value == 0).
+ * After that point, any additional data starts a new frame.
+ * note : each frame is independent (does not reference any content from previous frame).
+ : note : multithreaded compression will block to flush as much output as possible. */
+} ZSTD_EndDirective;
+
+/*! ZSTD_compressStream2() : Requires v1.4.0+
+ * Behaves about the same as ZSTD_compressStream, with additional control on end directive.
+ * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
+ * - Compression parameters cannot be changed once compression is started (save a list of exceptions in multi-threading mode)
+ * - output->pos must be <= dstCapacity, input->pos must be <= srcSize
+ * - output->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
+ * - endOp must be a valid directive
+ * - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
+ * - When nbWorkers>=1, function is non-blocking : it copies a portion of input, distributes jobs to internal worker threads, flush to output whatever is available,
+ * and then immediately returns, just indicating that there is some data remaining to be flushed.
+ * The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
+ * - Exception : if the first call requests a ZSTD_e_end directive and provides enough dstCapacity, the function delegates to ZSTD_compress2() which is always blocking.
+ * - @return provides a minimum amount of data remaining to be flushed from internal buffers
+ * or an error code, which can be tested using ZSTD_isError().
+ * if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
+ * This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
+ * For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
+ * - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
+ * only ZSTD_e_end or ZSTD_e_flush operations are allowed.
+ * Before starting a new compression job, or changing compression parameters,
+ * it is required to fully flush internal buffers.
+ */
+ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
+ ZSTD_outBuffer* output,
+ ZSTD_inBuffer* input,
+ ZSTD_EndDirective endOp);
+
+
+/* These buffer sizes are softly recommended.
+ * They are not required : ZSTD_compressStream*() happily accepts any buffer size, for both input and output.
+ * Respecting the recommended size just makes it a bit easier for ZSTD_compressStream*(),
+ * reducing the amount of memory shuffling and buffering, resulting in minor performance savings.
+ *
+ * However, note that these recommendations are from the perspective of a C caller program.
+ * If the streaming interface is invoked from some other language,
+ * especially managed ones such as Java or Go, through a foreign function interface such as jni or cgo,
+ * a major performance rule is to reduce crossing such interface to an absolute minimum.
+ * It's not rare that performance ends being spent more into the interface, rather than compression itself.
+ * In which cases, prefer using large buffers, as large as practical,
+ * for both input and output, to reduce the nb of roundtrips.
+ */
+ZSTDLIB_API size_t ZSTD_CStreamInSize(void); /**< recommended size for input buffer */
+ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block. */
+
+
+/* *****************************************************************************
+ * This following is a legacy streaming API, available since v1.0+ .
+ * It can be replaced by ZSTD_CCtx_reset() and ZSTD_compressStream2().
+ * It is redundant, but remains fully supported.
+ ******************************************************************************/
+
+/*!
+ * Equivalent to:
+ *
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ *
+ * Note that ZSTD_initCStream() clears any previously set dictionary. Use the new API
+ * to compress with a dictionary.
+ */
+ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
+/*!
+ * Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).
+ * NOTE: The return value is different. ZSTD_compressStream() returns a hint for
+ * the next read size (if non-zero and not an error). ZSTD_compressStream2()
+ * returns the minimum nb of bytes left to flush (if non-zero and not an error).
+ */
+ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
+/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush). */
+ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end). */
+ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+
+
+/*-***************************************************************************
+* Streaming decompression - HowTo
+*
+* A ZSTD_DStream object is required to track streaming operations.
+* Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources.
+* ZSTD_DStream objects can be re-used multiple times.
+*
+* Use ZSTD_initDStream() to start a new decompression operation.
+* @return : recommended first input size
+* Alternatively, use advanced API to set specific properties.
+*
+* Use ZSTD_decompressStream() repetitively to consume your input.
+* The function will update both `pos` fields.
+* If `input.pos < input.size`, some input has not been consumed.
+* It's up to the caller to present again remaining data.
+* The function tries to flush all data decoded immediately, respecting output buffer size.
+* If `output.pos < output.size`, decoder has flushed everything it could.
+* But if `output.pos == output.size`, there might be some data left within internal buffers.,
+* In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
+* Note : with no additional input provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
+* @return : 0 when a frame is completely decoded and fully flushed,
+* or an error code, which can be tested using ZSTD_isError(),
+* or any other value > 0, which means there is still some decoding or flushing to do to complete current frame :
+* the return value is a suggested next input size (just a hint for better latency)
+* that will never request more than the remaining frame size.
+* *******************************************************************************/
+
+typedef ZSTD_DCtx ZSTD_DStream; /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
+ /* For compatibility with versions <= v1.2.0, prefer differentiating them. */
+/*===== ZSTD_DStream management functions =====*/
+ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
+ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds); /* accept NULL pointer */
+
+/*===== Streaming decompression functions =====*/
+
+/*! ZSTD_initDStream() :
+ * Initialize/reset DStream state for new decompression operation.
+ * Call before new decompression operation using same DStream.
+ *
+ * Note : This function is redundant with the advanced API and equivalent to:
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ * ZSTD_DCtx_refDDict(zds, NULL);
+ */
+ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);
+
+/*! ZSTD_decompressStream() :
+ * Streaming decompression function.
+ * Call repetitively to consume full input updating it as necessary.
+ * Function will update both input and output `pos` fields exposing current state via these fields:
+ * - `input.pos < input.size`, some input remaining and caller should provide remaining input
+ * on the next call.
+ * - `output.pos < output.size`, decoder finished and flushed all remaining buffers.
+ * - `output.pos == output.size`, potentially uncflushed data present in the internal buffers,
+ * call ZSTD_decompressStream() again to flush remaining data to output.
+ * Note : with no additional input, amount of data flushed <= ZSTD_BLOCKSIZE_MAX.
+ *
+ * @return : 0 when a frame is completely decoded and fully flushed,
+ * or an error code, which can be tested using ZSTD_isError(),
+ * or any other value > 0, which means there is some decoding or flushing to do to complete current frame.
+ */
+ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
+
+ZSTDLIB_API size_t ZSTD_DStreamInSize(void); /*!< recommended size for input buffer */
+ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
+
+
+/**************************
+* Simple dictionary API
+***************************/
+/*! ZSTD_compress_usingDict() :
+ * Compression at an explicit compression level using a Dictionary.
+ * A dictionary can be any arbitrary data segment (also called a prefix),
+ * or a buffer with specified information (see zdict.h).
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * It's intended for a dictionary used only once.
+ * Note 2 : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ZSTDLIB_API size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize,
+ int compressionLevel);
+
+/*! ZSTD_decompress_usingDict() :
+ * Decompression using a known Dictionary.
+ * Dictionary must be identical to the one used during compression.
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * It's intended for a dictionary used only once.
+ * Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ZSTDLIB_API size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize);
+
+
+/***********************************
+ * Bulk processing dictionary API
+ **********************************/
+typedef struct ZSTD_CDict_s ZSTD_CDict;
+
+/*! ZSTD_createCDict() :
+ * When compressing multiple messages or blocks using the same dictionary,
+ * it's recommended to digest the dictionary only once, since it's a costly operation.
+ * ZSTD_createCDict() will create a state from digesting a dictionary.
+ * The resulting state can be used for future compression operations with very limited startup cost.
+ * ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * @dictBuffer can be released after ZSTD_CDict creation, because its content is copied within CDict.
+ * Note 1 : Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate @dictBuffer content.
+ * Note 2 : A ZSTD_CDict can be created from an empty @dictBuffer,
+ * in which case the only thing that it transports is the @compressionLevel.
+ * This can be useful in a pipeline featuring ZSTD_compress_usingCDict() exclusively,
+ * expecting a ZSTD_CDict parameter with any data, including those without a known dictionary. */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
+ int compressionLevel);
+
+/*! ZSTD_freeCDict() :
+ * Function frees memory allocated by ZSTD_createCDict().
+ * If a NULL pointer is passed, no operation is performed. */
+ZSTDLIB_API size_t ZSTD_freeCDict(ZSTD_CDict* CDict);
+
+/*! ZSTD_compress_usingCDict() :
+ * Compression using a digested Dictionary.
+ * Recommended when same dictionary is used multiple times.
+ * Note : compression level is _decided at dictionary creation time_,
+ * and frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) */
+ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_CDict* cdict);
+
+
+typedef struct ZSTD_DDict_s ZSTD_DDict;
+
+/*! ZSTD_createDDict() :
+ * Create a digested dictionary, ready to start decompression operation without startup delay.
+ * dictBuffer can be released after DDict creation, as its content is copied inside DDict. */
+ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
+
+/*! ZSTD_freeDDict() :
+ * Function frees memory allocated with ZSTD_createDDict()
+ * If a NULL pointer is passed, no operation is performed. */
+ZSTDLIB_API size_t ZSTD_freeDDict(ZSTD_DDict* ddict);
+
+/*! ZSTD_decompress_usingDDict() :
+ * Decompression using a digested Dictionary.
+ * Recommended when same dictionary is used multiple times. */
+ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_DDict* ddict);
+
+
+/********************************
+ * Dictionary helper functions
+ *******************************/
+
+/*! ZSTD_getDictID_fromDict() : Requires v1.4.0+
+ * Provides the dictID stored within dictionary.
+ * if @return == 0, the dictionary is not conformant with Zstandard specification.
+ * It can still be loaded, but as a content-only dictionary. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
+
+/*! ZSTD_getDictID_fromCDict() : Requires v1.5.0+
+ * Provides the dictID of the dictionary loaded into `cdict`.
+ * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+ * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromCDict(const ZSTD_CDict* cdict);
+
+/*! ZSTD_getDictID_fromDDict() : Requires v1.4.0+
+ * Provides the dictID of the dictionary loaded into `ddict`.
+ * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+ * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
+
+/*! ZSTD_getDictID_fromFrame() : Requires v1.4.0+
+ * Provides the dictID required to decompressed the frame stored within `src`.
+ * If @return == 0, the dictID could not be decoded.
+ * This could for one of the following reasons :
+ * - The frame does not require a dictionary to be decoded (most common case).
+ * - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden piece of information.
+ * Note : this use case also happens when using a non-conformant dictionary.
+ * - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
+ * - This is not a Zstandard frame.
+ * When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. */
+ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
+
+
+/*******************************************************************************
+ * Advanced dictionary and prefix API (Requires v1.4.0+)
+ *
+ * This API allows dictionaries to be used with ZSTD_compress2(),
+ * ZSTD_compressStream2(), and ZSTD_decompressDCtx().
+ * Dictionaries are sticky, they remain valid when same context is re-used,
+ * they only reset when the context is reset
+ * with ZSTD_reset_parameters or ZSTD_reset_session_and_parameters.
+ * In contrast, Prefixes are single-use.
+ ******************************************************************************/
+
+
+/*! ZSTD_CCtx_loadDictionary() : Requires v1.4.0+
+ * Create an internal CDict from `dict` buffer.
+ * Decompression will have to use same dictionary.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Loading a NULL (or 0-size) dictionary invalidates previous dictionary,
+ * meaning "return to no-dictionary mode".
+ * Note 1 : Dictionary is sticky, it will be used for all future compressed frames,
+ * until parameters are reset, a new dictionary is loaded, or the dictionary
+ * is explicitly invalidated by loading a NULL dictionary.
+ * Note 2 : Loading a dictionary involves building tables.
+ * It's also a CPU consuming operation, with non-negligible impact on latency.
+ * Tables are dependent on compression parameters, and for this reason,
+ * compression parameters can no longer be changed after loading a dictionary.
+ * Note 3 :`dict` content will be copied internally.
+ * Use experimental ZSTD_CCtx_loadDictionary_byReference() to reference content instead.
+ * In such a case, dictionary buffer must outlive its users.
+ * Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
+ * to precisely select how dictionary content must be interpreted.
+ * Note 5 : This method does not benefit from LDM (long distance mode).
+ * If you want to employ LDM on some large dictionary content,
+ * prefer employing ZSTD_CCtx_refPrefix() described below.
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
+
+/*! ZSTD_CCtx_refCDict() : Requires v1.4.0+
+ * Reference a prepared dictionary, to be used for all future compressed frames.
+ * Note that compression parameters are enforced from within CDict,
+ * and supersede any compression parameter previously set within CCtx.
+ * The parameters ignored are labelled as "superseded-by-cdict" in the ZSTD_cParameter enum docs.
+ * The ignored parameters will be used again if the CCtx is returned to no-dictionary mode.
+ * The dictionary will remain valid for future compressed frames using same CCtx.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special : Referencing a NULL CDict means "return to no-dictionary mode".
+ * Note 1 : Currently, only one dictionary can be managed.
+ * Referencing a new dictionary effectively "discards" any previous one.
+ * Note 2 : CDict is just referenced, its lifetime must outlive its usage within CCtx. */
+ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
+
+/*! ZSTD_CCtx_refPrefix() : Requires v1.4.0+
+ * Reference a prefix (single-usage dictionary) for next compressed frame.
+ * A prefix is **only used once**. Tables are discarded at end of frame (ZSTD_e_end).
+ * Decompression will need same prefix to properly regenerate data.
+ * Compressing with a prefix is similar in outcome as performing a diff and compressing it,
+ * but performs much faster, especially during decompression (compression speed is tunable with compression level).
+ * This method is compatible with LDM (long distance mode).
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
+ * Note 1 : Prefix buffer is referenced. It **must** outlive compression.
+ * Its content must remain unmodified during compression.
+ * Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
+ * ensure that the window size is large enough to contain the entire source.
+ * See ZSTD_c_windowLog.
+ * Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
+ * It's a CPU consuming operation, with non-negligible impact on latency.
+ * If there is a need to use the same prefix multiple times, consider loadDictionary instead.
+ * Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dct_rawContent).
+ * Use experimental ZSTD_CCtx_refPrefix_advanced() to alter dictionary interpretation. */
+ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
+ const void* prefix, size_t prefixSize);
+
+/*! ZSTD_DCtx_loadDictionary() : Requires v1.4.0+
+ * Create an internal DDict from dict buffer, to be used to decompress all future frames.
+ * The dictionary remains valid for all future frames, until explicitly invalidated, or
+ * a new dictionary is loaded.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special : Adding a NULL (or 0-size) dictionary invalidates any previous dictionary,
+ * meaning "return to no-dictionary mode".
+ * Note 1 : Loading a dictionary involves building tables,
+ * which has a non-negligible impact on CPU usage and latency.
+ * It's recommended to "load once, use many times", to amortize the cost
+ * Note 2 :`dict` content will be copied internally, so `dict` can be released after loading.
+ * Use ZSTD_DCtx_loadDictionary_byReference() to reference dictionary content instead.
+ * Note 3 : Use ZSTD_DCtx_loadDictionary_advanced() to take control of
+ * how dictionary content is loaded and interpreted.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
+
+/*! ZSTD_DCtx_refDDict() : Requires v1.4.0+
+ * Reference a prepared dictionary, to be used to decompress next frames.
+ * The dictionary remains active for decompression of future frames using same DCtx.
+ *
+ * If called with ZSTD_d_refMultipleDDicts enabled, repeated calls of this function
+ * will store the DDict references in a table, and the DDict used for decompression
+ * will be determined at decompression time, as per the dict ID in the frame.
+ * The memory for the table is allocated on the first call to refDDict, and can be
+ * freed with ZSTD_freeDCtx().
+ *
+ * If called with ZSTD_d_refMultipleDDicts disabled (the default), only one dictionary
+ * will be managed, and referencing a dictionary effectively "discards" any previous one.
+ *
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: referencing a NULL DDict means "return to no-dictionary mode".
+ * Note 2 : DDict is just referenced, its lifetime must outlive its usage from DCtx.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
+
+/*! ZSTD_DCtx_refPrefix() : Requires v1.4.0+
+ * Reference a prefix (single-usage dictionary) to decompress next frame.
+ * This is the reverse operation of ZSTD_CCtx_refPrefix(),
+ * and must use the same prefix as the one used during compression.
+ * Prefix is **only used once**. Reference is discarded at end of frame.
+ * End of frame is reached when ZSTD_decompressStream() returns 0.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Note 1 : Adding any prefix (including NULL) invalidates any previously set prefix or dictionary
+ * Note 2 : Prefix buffer is referenced. It **must** outlive decompression.
+ * Prefix buffer must remain unmodified up to the end of frame,
+ * reached when ZSTD_decompressStream() returns 0.
+ * Note 3 : By default, the prefix is treated as raw content (ZSTD_dct_rawContent).
+ * Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode (Experimental section)
+ * Note 4 : Referencing a raw content prefix has almost no cpu nor memory cost.
+ * A full dictionary is more costly, as it requires building tables.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx,
+ const void* prefix, size_t prefixSize);
+
+/* === Memory management === */
+
+/*! ZSTD_sizeof_*() : Requires v1.4.0+
+ * These functions give the _current_ memory usage of selected object.
+ * Note that object memory usage can evolve (increase or decrease) over time. */
+ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
+ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
+ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
+ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
+ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
+
+#endif /* ZSTD_H_235446 */
+
+
+/* **************************************************************************************
+ * ADVANCED AND EXPERIMENTAL FUNCTIONS
+ ****************************************************************************************
+ * The definitions in the following section are considered experimental.
+ * They are provided for advanced scenarios.
+ * They should never be used with a dynamic library, as prototypes may change in the future.
+ * Use them only in association with static linking.
+ * ***************************************************************************************/
+
+#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
+#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
+
+/* This can be overridden externally to hide static symbols. */
+#ifndef ZSTDLIB_STATIC_API
+# if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
+# define ZSTDLIB_STATIC_API __declspec(dllexport) ZSTDLIB_VISIBLE
+# elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
+# define ZSTDLIB_STATIC_API __declspec(dllimport) ZSTDLIB_VISIBLE
+# else
+# define ZSTDLIB_STATIC_API ZSTDLIB_VISIBLE
+# endif
+#endif
+
+/****************************************************************************************
+ * experimental API (static linking only)
+ ****************************************************************************************
+ * The following symbols and constants
+ * are not planned to join "stable API" status in the near future.
+ * They can still change in future versions.
+ * Some of them are planned to remain in the static_only section indefinitely.
+ * Some of them might be removed in the future (especially when redundant with existing stable functions)
+ * ***************************************************************************************/
+
+#define ZSTD_FRAMEHEADERSIZE_PREFIX(format) ((format) == ZSTD_f_zstd1 ? 5 : 1) /* minimum input size required to query frame header size */
+#define ZSTD_FRAMEHEADERSIZE_MIN(format) ((format) == ZSTD_f_zstd1 ? 6 : 2)
+#define ZSTD_FRAMEHEADERSIZE_MAX 18 /* can be useful for static allocation */
+#define ZSTD_SKIPPABLEHEADERSIZE 8
+
+/* compression parameter bounds */
+#define ZSTD_WINDOWLOG_MAX_32 30
+#define ZSTD_WINDOWLOG_MAX_64 31
+#define ZSTD_WINDOWLOG_MAX ((int)(sizeof(size_t) == 4 ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
+#define ZSTD_WINDOWLOG_MIN 10
+#define ZSTD_HASHLOG_MAX ((ZSTD_WINDOWLOG_MAX < 30) ? ZSTD_WINDOWLOG_MAX : 30)
+#define ZSTD_HASHLOG_MIN 6
+#define ZSTD_CHAINLOG_MAX_32 29
+#define ZSTD_CHAINLOG_MAX_64 30
+#define ZSTD_CHAINLOG_MAX ((int)(sizeof(size_t) == 4 ? ZSTD_CHAINLOG_MAX_32 : ZSTD_CHAINLOG_MAX_64))
+#define ZSTD_CHAINLOG_MIN ZSTD_HASHLOG_MIN
+#define ZSTD_SEARCHLOG_MAX (ZSTD_WINDOWLOG_MAX-1)
+#define ZSTD_SEARCHLOG_MIN 1
+#define ZSTD_MINMATCH_MAX 7 /* only for ZSTD_fast, other strategies are limited to 6 */
+#define ZSTD_MINMATCH_MIN 3 /* only for ZSTD_btopt+, faster strategies are limited to 4 */
+#define ZSTD_TARGETLENGTH_MAX ZSTD_BLOCKSIZE_MAX
+#define ZSTD_TARGETLENGTH_MIN 0 /* note : comparing this constant to an unsigned results in a tautological test */
+#define ZSTD_STRATEGY_MIN ZSTD_fast
+#define ZSTD_STRATEGY_MAX ZSTD_btultra2
+#define ZSTD_BLOCKSIZE_MAX_MIN (1 << 10) /* The minimum valid max blocksize. Maximum blocksizes smaller than this make compressBound() inaccurate. */
+
+
+#define ZSTD_OVERLAPLOG_MIN 0
+#define ZSTD_OVERLAPLOG_MAX 9
+
+#define ZSTD_WINDOWLOG_LIMIT_DEFAULT 27 /* by default, the streaming decoder will refuse any frame
+ * requiring larger than (1<<ZSTD_WINDOWLOG_LIMIT_DEFAULT) window size,
+ * to preserve host's memory from unreasonable requirements.
+ * This limit can be overridden using ZSTD_DCtx_setParameter(,ZSTD_d_windowLogMax,).
+ * The limit does not apply for one-pass decoders (such as ZSTD_decompress()), since no additional memory is allocated */
+
+
+/* LDM parameter bounds */
+#define ZSTD_LDM_HASHLOG_MIN ZSTD_HASHLOG_MIN
+#define ZSTD_LDM_HASHLOG_MAX ZSTD_HASHLOG_MAX
+#define ZSTD_LDM_MINMATCH_MIN 4
+#define ZSTD_LDM_MINMATCH_MAX 4096
+#define ZSTD_LDM_BUCKETSIZELOG_MIN 1
+#define ZSTD_LDM_BUCKETSIZELOG_MAX 8
+#define ZSTD_LDM_HASHRATELOG_MIN 0
+#define ZSTD_LDM_HASHRATELOG_MAX (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN)
+
+/* Advanced parameter bounds */
+#define ZSTD_TARGETCBLOCKSIZE_MIN 64
+#define ZSTD_TARGETCBLOCKSIZE_MAX ZSTD_BLOCKSIZE_MAX
+#define ZSTD_SRCSIZEHINT_MIN 0
+#define ZSTD_SRCSIZEHINT_MAX INT_MAX
+
+
+/* --- Advanced types --- */
+
+typedef struct ZSTD_CCtx_params_s ZSTD_CCtx_params;
+
+typedef struct {
+ unsigned int offset; /* The offset of the match. (NOT the same as the offset code)
+ * If offset == 0 and matchLength == 0, this sequence represents the last
+ * literals in the block of litLength size.
+ */
+
+ unsigned int litLength; /* Literal length of the sequence. */
+ unsigned int matchLength; /* Match length of the sequence. */
+
+ /* Note: Users of this API may provide a sequence with matchLength == litLength == offset == 0.
+ * In this case, we will treat the sequence as a marker for a block boundary.
+ */
+
+ unsigned int rep; /* Represents which repeat offset is represented by the field 'offset'.
+ * Ranges from [0, 3].
+ *
+ * Repeat offsets are essentially previous offsets from previous sequences sorted in
+ * recency order. For more detail, see doc/zstd_compression_format.md
+ *
+ * If rep == 0, then 'offset' does not contain a repeat offset.
+ * If rep > 0:
+ * If litLength != 0:
+ * rep == 1 --> offset == repeat_offset_1
+ * rep == 2 --> offset == repeat_offset_2
+ * rep == 3 --> offset == repeat_offset_3
+ * If litLength == 0:
+ * rep == 1 --> offset == repeat_offset_2
+ * rep == 2 --> offset == repeat_offset_3
+ * rep == 3 --> offset == repeat_offset_1 - 1
+ *
+ * Note: This field is optional. ZSTD_generateSequences() will calculate the value of
+ * 'rep', but repeat offsets do not necessarily need to be calculated from an external
+ * sequence provider's perspective. For example, ZSTD_compressSequences() does not
+ * use this 'rep' field at all (as of now).
+ */
+} ZSTD_Sequence;
+
+typedef struct {
+ unsigned windowLog; /**< largest match distance : larger == more compression, more memory needed during decompression */
+ unsigned chainLog; /**< fully searched segment : larger == more compression, slower, more memory (useless for fast) */
+ unsigned hashLog; /**< dispatch table : larger == faster, more memory */
+ unsigned searchLog; /**< nb of searches : larger == more compression, slower */
+ unsigned minMatch; /**< match length searched : larger == faster decompression, sometimes less compression */
+ unsigned targetLength; /**< acceptable match size for optimal parser (only) : larger == more compression, slower */
+ ZSTD_strategy strategy; /**< see ZSTD_strategy definition above */
+} ZSTD_compressionParameters;
+
+typedef struct {
+ int contentSizeFlag; /**< 1: content size will be in frame header (when known) */
+ int checksumFlag; /**< 1: generate a 32-bits checksum using XXH64 algorithm at end of frame, for error detection */
+ int noDictIDFlag; /**< 1: no dictID will be saved into frame header (dictID is only useful for dictionary compression) */
+} ZSTD_frameParameters;
+
+typedef struct {
+ ZSTD_compressionParameters cParams;
+ ZSTD_frameParameters fParams;
+} ZSTD_parameters;
+
+typedef enum {
+ ZSTD_dct_auto = 0, /* dictionary is "full" when starting with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
+ ZSTD_dct_rawContent = 1, /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
+ ZSTD_dct_fullDict = 2 /* refuses to load a dictionary if it does not respect Zstandard's specification, starting with ZSTD_MAGIC_DICTIONARY */
+} ZSTD_dictContentType_e;
+
+typedef enum {
+ ZSTD_dlm_byCopy = 0, /**< Copy dictionary content internally */
+ ZSTD_dlm_byRef = 1 /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
+} ZSTD_dictLoadMethod_e;
+
+typedef enum {
+ ZSTD_f_zstd1 = 0, /* zstd frame format, specified in zstd_compression_format.md (default) */
+ ZSTD_f_zstd1_magicless = 1 /* Variant of zstd frame format, without initial 4-bytes magic number.
+ * Useful to save 4 bytes per generated frame.
+ * Decoder cannot recognise automatically this format, requiring this instruction. */
+} ZSTD_format_e;
+
+typedef enum {
+ /* Note: this enum controls ZSTD_d_forceIgnoreChecksum */
+ ZSTD_d_validateChecksum = 0,
+ ZSTD_d_ignoreChecksum = 1
+} ZSTD_forceIgnoreChecksum_e;
+
+typedef enum {
+ /* Note: this enum controls ZSTD_d_refMultipleDDicts */
+ ZSTD_rmd_refSingleDDict = 0,
+ ZSTD_rmd_refMultipleDDicts = 1
+} ZSTD_refMultipleDDicts_e;
+
+typedef enum {
+ /* Note: this enum and the behavior it controls are effectively internal
+ * implementation details of the compressor. They are expected to continue
+ * to evolve and should be considered only in the context of extremely
+ * advanced performance tuning.
+ *
+ * Zstd currently supports the use of a CDict in three ways:
+ *
+ * - The contents of the CDict can be copied into the working context. This
+ * means that the compression can search both the dictionary and input
+ * while operating on a single set of internal tables. This makes
+ * the compression faster per-byte of input. However, the initial copy of
+ * the CDict's tables incurs a fixed cost at the beginning of the
+ * compression. For small compressions (< 8 KB), that copy can dominate
+ * the cost of the compression.
+ *
+ * - The CDict's tables can be used in-place. In this model, compression is
+ * slower per input byte, because the compressor has to search two sets of
+ * tables. However, this model incurs no start-up cost (as long as the
+ * working context's tables can be reused). For small inputs, this can be
+ * faster than copying the CDict's tables.
+ *
+ * - The CDict's tables are not used at all, and instead we use the working
+ * context alone to reload the dictionary and use params based on the source
+ * size. See ZSTD_compress_insertDictionary() and ZSTD_compress_usingDict().
+ * This method is effective when the dictionary sizes are very small relative
+ * to the input size, and the input size is fairly large to begin with.
+ *
+ * Zstd has a simple internal heuristic that selects which strategy to use
+ * at the beginning of a compression. However, if experimentation shows that
+ * Zstd is making poor choices, it is possible to override that choice with
+ * this enum.
+ */
+ ZSTD_dictDefaultAttach = 0, /* Use the default heuristic. */
+ ZSTD_dictForceAttach = 1, /* Never copy the dictionary. */
+ ZSTD_dictForceCopy = 2, /* Always copy the dictionary. */
+ ZSTD_dictForceLoad = 3 /* Always reload the dictionary */
+} ZSTD_dictAttachPref_e;
+
+typedef enum {
+ ZSTD_lcm_auto = 0, /**< Automatically determine the compression mode based on the compression level.
+ * Negative compression levels will be uncompressed, and positive compression
+ * levels will be compressed. */
+ ZSTD_lcm_huffman = 1, /**< Always attempt Huffman compression. Uncompressed literals will still be
+ * emitted if Huffman compression is not profitable. */
+ ZSTD_lcm_uncompressed = 2 /**< Always emit uncompressed literals. */
+} ZSTD_literalCompressionMode_e;
+
+typedef enum {
+ /* Note: This enum controls features which are conditionally beneficial. Zstd typically will make a final
+ * decision on whether or not to enable the feature (ZSTD_ps_auto), but setting the switch to ZSTD_ps_enable
+ * or ZSTD_ps_disable allow for a force enable/disable the feature.
+ */
+ ZSTD_ps_auto = 0, /* Let the library automatically determine whether the feature shall be enabled */
+ ZSTD_ps_enable = 1, /* Force-enable the feature */
+ ZSTD_ps_disable = 2 /* Do not use the feature */
+} ZSTD_paramSwitch_e;
+
+/***************************************
+* Frame header and size functions
+***************************************/
+
+/*! ZSTD_findDecompressedSize() :
+ * `src` should point to the start of a series of ZSTD encoded and/or skippable frames
+ * `srcSize` must be the _exact_ size of this series
+ * (i.e. there should be a frame boundary at `src + srcSize`)
+ * @return : - decompressed size of all data in all successive frames
+ * - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
+ * - if an error occurred: ZSTD_CONTENTSIZE_ERROR
+ *
+ * note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
+ * When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 2 : decompressed size is always present when compression is done with ZSTD_compress()
+ * note 3 : decompressed size can be very large (64-bits value),
+ * potentially larger than what local system can handle as a single memory segment.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
+ * Always ensure result fits within application's authorized limits.
+ * Each application can set its own limits.
+ * note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
+ * read each contained frame header. This is fast as most of the data is skipped,
+ * however it does mean that all frame data must be present and valid. */
+ZSTDLIB_STATIC_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
+
+/*! ZSTD_decompressBound() :
+ * `src` should point to the start of a series of ZSTD encoded and/or skippable frames
+ * `srcSize` must be the _exact_ size of this series
+ * (i.e. there should be a frame boundary at `src + srcSize`)
+ * @return : - upper-bound for the decompressed size of all data in all successive frames
+ * - if an error occurred: ZSTD_CONTENTSIZE_ERROR
+ *
+ * note 1 : an error can occur if `src` contains an invalid or incorrectly formatted frame.
+ * note 2 : the upper-bound is exact when the decompressed size field is available in every ZSTD encoded frame of `src`.
+ * in this case, `ZSTD_findDecompressedSize` and `ZSTD_decompressBound` return the same value.
+ * note 3 : when the decompressed size field isn't available, the upper-bound for that frame is calculated by:
+ * upper-bound = # blocks * min(128 KB, Window_Size)
+ */
+ZSTDLIB_STATIC_API unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize);
+
+/*! ZSTD_frameHeaderSize() :
+ * srcSize must be >= ZSTD_FRAMEHEADERSIZE_PREFIX.
+ * @return : size of the Frame Header,
+ * or an error code (if srcSize is too small) */
+ZSTDLIB_STATIC_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
+
+typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
+typedef struct {
+ unsigned long long frameContentSize; /* if == ZSTD_CONTENTSIZE_UNKNOWN, it means this field is not available. 0 means "empty" */
+ unsigned long long windowSize; /* can be very large, up to <= frameContentSize */
+ unsigned blockSizeMax;
+ ZSTD_frameType_e frameType; /* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */
+ unsigned headerSize;
+ unsigned dictID;
+ unsigned checksumFlag;
+ unsigned _reserved1;
+ unsigned _reserved2;
+} ZSTD_frameHeader;
+
+/*! ZSTD_getFrameHeader() :
+ * decode Frame Header, or requires larger `srcSize`.
+ * @return : 0, `zfhPtr` is correctly filled,
+ * >0, `srcSize` is too small, value is wanted `srcSize` amount,
+ * or an error code, which can be tested using ZSTD_isError() */
+ZSTDLIB_STATIC_API size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); /**< doesn't consume input */
+/*! ZSTD_getFrameHeader_advanced() :
+ * same as ZSTD_getFrameHeader(),
+ * with added capability to select a format (like ZSTD_f_zstd1_magicless) */
+ZSTDLIB_STATIC_API size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format);
+
+/*! ZSTD_decompressionMargin() :
+ * Zstd supports in-place decompression, where the input and output buffers overlap.
+ * In this case, the output buffer must be at least (Margin + Output_Size) bytes large,
+ * and the input buffer must be at the end of the output buffer.
+ *
+ * _______________________ Output Buffer ________________________
+ * | |
+ * | ____ Input Buffer ____|
+ * | | |
+ * v v v
+ * |---------------------------------------|-----------|----------|
+ * ^ ^ ^
+ * |___________________ Output_Size ___________________|_ Margin _|
+ *
+ * NOTE: See also ZSTD_DECOMPRESSION_MARGIN().
+ * NOTE: This applies only to single-pass decompression through ZSTD_decompress() or
+ * ZSTD_decompressDCtx().
+ * NOTE: This function supports multi-frame input.
+ *
+ * @param src The compressed frame(s)
+ * @param srcSize The size of the compressed frame(s)
+ * @returns The decompression margin or an error that can be checked with ZSTD_isError().
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_decompressionMargin(const void* src, size_t srcSize);
+
+/*! ZSTD_DECOMPRESS_MARGIN() :
+ * Similar to ZSTD_decompressionMargin(), but instead of computing the margin from
+ * the compressed frame, compute it from the original size and the blockSizeLog.
+ * See ZSTD_decompressionMargin() for details.
+ *
+ * WARNING: This macro does not support multi-frame input, the input must be a single
+ * zstd frame. If you need that support use the function, or implement it yourself.
+ *
+ * @param originalSize The original uncompressed size of the data.
+ * @param blockSize The block size == MIN(windowSize, ZSTD_BLOCKSIZE_MAX).
+ * Unless you explicitly set the windowLog smaller than
+ * ZSTD_BLOCKSIZELOG_MAX you can just use ZSTD_BLOCKSIZE_MAX.
+ */
+#define ZSTD_DECOMPRESSION_MARGIN(originalSize, blockSize) ((size_t)( \
+ ZSTD_FRAMEHEADERSIZE_MAX /* Frame header */ + \
+ 4 /* checksum */ + \
+ ((originalSize) == 0 ? 0 : 3 * (((originalSize) + (blockSize) - 1) / blockSize)) /* 3 bytes per block */ + \
+ (blockSize) /* One block of margin */ \
+ ))
+
+typedef enum {
+ ZSTD_sf_noBlockDelimiters = 0, /* Representation of ZSTD_Sequence has no block delimiters, sequences only */
+ ZSTD_sf_explicitBlockDelimiters = 1 /* Representation of ZSTD_Sequence contains explicit block delimiters */
+} ZSTD_sequenceFormat_e;
+
+/*! ZSTD_sequenceBound() :
+ * `srcSize` : size of the input buffer
+ * @return : upper-bound for the number of sequences that can be generated
+ * from a buffer of srcSize bytes
+ *
+ * note : returns number of sequences - to get bytes, multiply by sizeof(ZSTD_Sequence).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_sequenceBound(size_t srcSize);
+
+/*! ZSTD_generateSequences() :
+ * Generate sequences using ZSTD_compress2(), given a source buffer.
+ *
+ * Each block will end with a dummy sequence
+ * with offset == 0, matchLength == 0, and litLength == length of last literals.
+ * litLength may be == 0, and if so, then the sequence of (of: 0 ml: 0 ll: 0)
+ * simply acts as a block delimiter.
+ *
+ * @zc can be used to insert custom compression params.
+ * This function invokes ZSTD_compress2().
+ *
+ * The output of this function can be fed into ZSTD_compressSequences() with CCtx
+ * setting of ZSTD_c_blockDelimiters as ZSTD_sf_explicitBlockDelimiters
+ * @return : number of sequences generated
+ */
+
+ZSTDLIB_STATIC_API size_t
+ZSTD_generateSequences( ZSTD_CCtx* zc,
+ ZSTD_Sequence* outSeqs, size_t outSeqsSize,
+ const void* src, size_t srcSize);
+
+/*! ZSTD_mergeBlockDelimiters() :
+ * Given an array of ZSTD_Sequence, remove all sequences that represent block delimiters/last literals
+ * by merging them into the literals of the next sequence.
+ *
+ * As such, the final generated result has no explicit representation of block boundaries,
+ * and the final last literals segment is not represented in the sequences.
+ *
+ * The output of this function can be fed into ZSTD_compressSequences() with CCtx
+ * setting of ZSTD_c_blockDelimiters as ZSTD_sf_noBlockDelimiters
+ * @return : number of sequences left after merging
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, size_t seqsSize);
+
+/*! ZSTD_compressSequences() :
+ * Compress an array of ZSTD_Sequence, associated with @src buffer, into dst.
+ * @src contains the entire input (not just the literals).
+ * If @srcSize > sum(sequence.length), the remaining bytes are considered all literals
+ * If a dictionary is included, then the cctx should reference the dict. (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.)
+ * The entire source is compressed into a single frame.
+ *
+ * The compression behavior changes based on cctx params. In particular:
+ * If ZSTD_c_blockDelimiters == ZSTD_sf_noBlockDelimiters, the array of ZSTD_Sequence is expected to contain
+ * no block delimiters (defined in ZSTD_Sequence). Block boundaries are roughly determined based on
+ * the block size derived from the cctx, and sequences may be split. This is the default setting.
+ *
+ * If ZSTD_c_blockDelimiters == ZSTD_sf_explicitBlockDelimiters, the array of ZSTD_Sequence is expected to contain
+ * block delimiters (defined in ZSTD_Sequence). Behavior is undefined if no block delimiters are provided.
+ *
+ * If ZSTD_c_validateSequences == 0, this function will blindly accept the sequences provided. Invalid sequences cause undefined
+ * behavior. If ZSTD_c_validateSequences == 1, then if sequence is invalid (see doc/zstd_compression_format.md for
+ * specifics regarding offset/matchlength requirements) then the function will bail out and return an error.
+ *
+ * In addition to the two adjustable experimental params, there are other important cctx params.
+ * - ZSTD_c_minMatch MUST be set as less than or equal to the smallest match generated by the match finder. It has a minimum value of ZSTD_MINMATCH_MIN.
+ * - ZSTD_c_compressionLevel accordingly adjusts the strength of the entropy coder, as it would in typical compression.
+ * - ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset
+ * is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md
+ *
+ * Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused.
+ * Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly,
+ * and cannot emit an RLE block that disagrees with the repcode history
+ * @return : final compressed size, or a ZSTD error code.
+ */
+ZSTDLIB_STATIC_API size_t
+ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize,
+ const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
+ const void* src, size_t srcSize);
+
+
+/*! ZSTD_writeSkippableFrame() :
+ * Generates a zstd skippable frame containing data given by src, and writes it to dst buffer.
+ *
+ * Skippable frames begin with a 4-byte magic number. There are 16 possible choices of magic number,
+ * ranging from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15.
+ * As such, the parameter magicVariant controls the exact skippable frame magic number variant used, so
+ * the magic number used will be ZSTD_MAGIC_SKIPPABLE_START + magicVariant.
+ *
+ * Returns an error if destination buffer is not large enough, if the source size is not representable
+ * with a 4-byte unsigned int, or if the parameter magicVariant is greater than 15 (and therefore invalid).
+ *
+ * @return : number of bytes written or a ZSTD error.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_writeSkippableFrame(void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize, unsigned magicVariant);
+
+/*! ZSTD_readSkippableFrame() :
+ * Retrieves a zstd skippable frame containing data given by src, and writes it to dst buffer.
+ *
+ * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written,
+ * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START. This can be NULL if the caller is not interested
+ * in the magicVariant.
+ *
+ * Returns an error if destination buffer is not large enough, or if the frame is not skippable.
+ *
+ * @return : number of bytes written or a ZSTD error.
+ */
+ZSTDLIB_API size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity, unsigned* magicVariant,
+ const void* src, size_t srcSize);
+
+/*! ZSTD_isSkippableFrame() :
+ * Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame.
+ */
+ZSTDLIB_API unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size);
+
+
+
+/***************************************
+* Memory management
+***************************************/
+
+/*! ZSTD_estimate*() :
+ * These functions make it possible to estimate memory usage
+ * of a future {D,C}Ctx, before its creation.
+ *
+ * ZSTD_estimateCCtxSize() will provide a memory budget large enough
+ * for any compression level up to selected one.
+ * Note : Unlike ZSTD_estimateCStreamSize*(), this estimate
+ * does not include space for a window buffer.
+ * Therefore, the estimation is only guaranteed for single-shot compressions, not streaming.
+ * The estimate will assume the input may be arbitrarily large,
+ * which is the worst case.
+ *
+ * When srcSize can be bound by a known and rather "small" value,
+ * this fact can be used to provide a tighter estimation
+ * because the CCtx compression context will need less memory.
+ * This tighter estimation can be provided by more advanced functions
+ * ZSTD_estimateCCtxSize_usingCParams(), which can be used in tandem with ZSTD_getCParams(),
+ * and ZSTD_estimateCCtxSize_usingCCtxParams(), which can be used in tandem with ZSTD_CCtxParams_setParameter().
+ * Both can be used to estimate memory using custom compression parameters and arbitrary srcSize limits.
+ *
+ * Note : only single-threaded compression is supported.
+ * ZSTD_estimateCCtxSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1.
+ *
+ * Note 2 : ZSTD_estimateCCtxSize* functions are not compatible with the Block-Level Sequence Producer API at this time.
+ * Size estimates assume that no external sequence producer is registered.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize(int compressionLevel);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateDCtxSize(void);
+
+/*! ZSTD_estimateCStreamSize() :
+ * ZSTD_estimateCStreamSize() will provide a budget large enough for any compression level up to selected one.
+ * It will also consider src size to be arbitrarily "large", which is worst case.
+ * If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation.
+ * ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
+ * ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParams_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
+ * Note : CStream size estimation is only correct for single-threaded compression.
+ * ZSTD_DStream memory budget depends on window Size.
+ * This information can be passed manually, using ZSTD_estimateDStreamSize,
+ * or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame();
+ * Note : if streaming is init with function ZSTD_init?Stream_usingDict(),
+ * an internal ?Dict will be created, which additional size is not estimated here.
+ * In this case, get total size by adding ZSTD_estimate?DictSize
+ * Note 2 : only single-threaded compression is supported.
+ * ZSTD_estimateCStreamSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1.
+ * Note 3 : ZSTD_estimateCStreamSize* functions are not compatible with the Block-Level Sequence Producer API at this time.
+ * Size estimates assume that no external sequence producer is registered.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize(int compressionLevel);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize(size_t windowSize);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize);
+
+/*! ZSTD_estimate?DictSize() :
+ * ZSTD_estimateCDictSize() will bet that src size is relatively "small", and content is copied, like ZSTD_createCDict().
+ * ZSTD_estimateCDictSize_advanced() makes it possible to control compression parameters precisely, like ZSTD_createCDict_advanced().
+ * Note : dictionaries created by reference (`ZSTD_dlm_byRef`) are logically smaller.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
+ZSTDLIB_STATIC_API size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod);
+
+/*! ZSTD_initStatic*() :
+ * Initialize an object using a pre-allocated fixed-size buffer.
+ * workspace: The memory area to emplace the object into.
+ * Provided pointer *must be 8-bytes aligned*.
+ * Buffer must outlive object.
+ * workspaceSize: Use ZSTD_estimate*Size() to determine
+ * how large workspace must be to support target scenario.
+ * @return : pointer to object (same address as workspace, just different type),
+ * or NULL if error (size too small, incorrect alignment, etc.)
+ * Note : zstd will never resize nor malloc() when using a static buffer.
+ * If the object requires more memory than available,
+ * zstd will just error out (typically ZSTD_error_memory_allocation).
+ * Note 2 : there is no corresponding "free" function.
+ * Since workspace is allocated externally, it must be freed externally too.
+ * Note 3 : cParams : use ZSTD_getCParams() to convert a compression level
+ * into its associated cParams.
+ * Limitation 1 : currently not compatible with internal dictionary creation, triggered by
+ * ZSTD_CCtx_loadDictionary(), ZSTD_initCStream_usingDict() or ZSTD_initDStream_usingDict().
+ * Limitation 2 : static cctx currently not compatible with multi-threading.
+ * Limitation 3 : static dctx is incompatible with legacy support.
+ */
+ZSTDLIB_STATIC_API ZSTD_CCtx* ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
+ZSTDLIB_STATIC_API ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticCCtx() */
+
+ZSTDLIB_STATIC_API ZSTD_DCtx* ZSTD_initStaticDCtx(void* workspace, size_t workspaceSize);
+ZSTDLIB_STATIC_API ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticDCtx() */
+
+ZSTDLIB_STATIC_API const ZSTD_CDict* ZSTD_initStaticCDict(
+ void* workspace, size_t workspaceSize,
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_compressionParameters cParams);
+
+ZSTDLIB_STATIC_API const ZSTD_DDict* ZSTD_initStaticDDict(
+ void* workspace, size_t workspaceSize,
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType);
+
+
+/*! Custom memory allocation :
+ * These prototypes make it possible to pass your own allocation/free functions.
+ * ZSTD_customMem is provided at creation time, using ZSTD_create*_advanced() variants listed below.
+ * All allocation/free operations will be completed using these custom variants instead of regular <stdlib.h> ones.
+ */
+typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
+typedef void (*ZSTD_freeFunction) (void* opaque, void* address);
+typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; void* opaque; } ZSTD_customMem;
+static
+#ifdef __GNUC__
+__attribute__((__unused__))
+#endif
+ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL }; /**< this constant defers to stdlib's functions */
+
+ZSTDLIB_STATIC_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
+ZSTDLIB_STATIC_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
+ZSTDLIB_STATIC_API ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
+ZSTDLIB_STATIC_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
+
+ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_compressionParameters cParams,
+ ZSTD_customMem customMem);
+
+/*! Thread pool :
+ * These prototypes make it possible to share a thread pool among multiple compression contexts.
+ * This can limit resources for applications with multiple threads where each one uses
+ * a threaded compression mode (via ZSTD_c_nbWorkers parameter).
+ * ZSTD_createThreadPool creates a new thread pool with a given number of threads.
+ * Note that the lifetime of such pool must exist while being used.
+ * ZSTD_CCtx_refThreadPool assigns a thread pool to a context (use NULL argument value
+ * to use an internal thread pool).
+ * ZSTD_freeThreadPool frees a thread pool, accepts NULL pointer.
+ */
+typedef struct POOL_ctx_s ZSTD_threadPool;
+ZSTDLIB_STATIC_API ZSTD_threadPool* ZSTD_createThreadPool(size_t numThreads);
+ZSTDLIB_STATIC_API void ZSTD_freeThreadPool (ZSTD_threadPool* pool); /* accept NULL pointer */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refThreadPool(ZSTD_CCtx* cctx, ZSTD_threadPool* pool);
+
+
+/*
+ * This API is temporary and is expected to change or disappear in the future!
+ */
+ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_advanced2(
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ const ZSTD_CCtx_params* cctxParams,
+ ZSTD_customMem customMem);
+
+ZSTDLIB_STATIC_API ZSTD_DDict* ZSTD_createDDict_advanced(
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_customMem customMem);
+
+
+/***************************************
+* Advanced compression functions
+***************************************/
+
+/*! ZSTD_createCDict_byReference() :
+ * Create a digested dictionary for compression
+ * Dictionary content is just referenced, not duplicated.
+ * As a consequence, `dictBuffer` **must** outlive CDict,
+ * and its content must remain unmodified throughout the lifetime of CDict.
+ * note: equivalent to ZSTD_createCDict_advanced(), with dictLoadMethod==ZSTD_dlm_byRef */
+ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
+
+/*! ZSTD_getCParams() :
+ * @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
+ * `estimatedSrcSize` value is optional, select 0 if not known */
+ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
+
+/*! ZSTD_getParams() :
+ * same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
+ * All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 */
+ZSTDLIB_STATIC_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
+
+/*! ZSTD_checkCParams() :
+ * Ensure param values remain within authorized range.
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()) */
+ZSTDLIB_STATIC_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
+
+/*! ZSTD_adjustCParams() :
+ * optimize params for a given `srcSize` and `dictSize`.
+ * `srcSize` can be unknown, in which case use ZSTD_CONTENTSIZE_UNKNOWN.
+ * `dictSize` must be `0` when there is no dictionary.
+ * cPar can be invalid : all parameters will be clamped within valid range in the @return struct.
+ * This function never fails (wide contract) */
+ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
+
+/*! ZSTD_CCtx_setCParams() :
+ * Set all parameters provided within @p cparams into the working @p cctx.
+ * Note : if modifying parameters during compression (MT mode only),
+ * note that changes to the .windowLog parameter will be ignored.
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
+ * On failure, no parameters are updated.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setCParams(ZSTD_CCtx* cctx, ZSTD_compressionParameters cparams);
+
+/*! ZSTD_CCtx_setFParams() :
+ * Set all parameters provided within @p fparams into the working @p cctx.
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setFParams(ZSTD_CCtx* cctx, ZSTD_frameParameters fparams);
+
+/*! ZSTD_CCtx_setParams() :
+ * Set all parameters provided within @p params into the working @p cctx.
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setParams(ZSTD_CCtx* cctx, ZSTD_parameters params);
+
+/*! ZSTD_compress_advanced() :
+ * Note : this function is now DEPRECATED.
+ * It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_setParameter() and other parameter setters.
+ * This prototype will generate compilation warnings. */
+ZSTD_DEPRECATED("use ZSTD_compress2")
+ZSTDLIB_STATIC_API
+size_t ZSTD_compress_advanced(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize,
+ ZSTD_parameters params);
+
+/*! ZSTD_compress_usingCDict_advanced() :
+ * Note : this function is now DEPRECATED.
+ * It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_loadDictionary() and other parameter setters.
+ * This prototype will generate compilation warnings. */
+ZSTD_DEPRECATED("use ZSTD_compress2 with ZSTD_CCtx_loadDictionary")
+ZSTDLIB_STATIC_API
+size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_CDict* cdict,
+ ZSTD_frameParameters fParams);
+
+
+/*! ZSTD_CCtx_loadDictionary_byReference() :
+ * Same as ZSTD_CCtx_loadDictionary(), but dictionary content is referenced, instead of being copied into CCtx.
+ * It saves some memory, but also requires that `dict` outlives its usage within `cctx` */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_loadDictionary_byReference(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
+
+/*! ZSTD_CCtx_loadDictionary_advanced() :
+ * Same as ZSTD_CCtx_loadDictionary(), but gives finer control over
+ * how to load the dictionary (by copy ? by reference ?)
+ * and how to interpret it (automatic ? force raw mode ? full mode only ?) */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
+
+/*! ZSTD_CCtx_refPrefix_advanced() :
+ * Same as ZSTD_CCtx_refPrefix(), but gives finer control over
+ * how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
+/* === experimental parameters === */
+/* these parameters can be used with ZSTD_setParameter()
+ * they are not guaranteed to remain supported in the future */
+
+ /* Enables rsyncable mode,
+ * which makes compressed files more rsync friendly
+ * by adding periodic synchronization points to the compressed data.
+ * The target average block size is ZSTD_c_jobSize / 2.
+ * It's possible to modify the job size to increase or decrease
+ * the granularity of the synchronization point.
+ * Once the jobSize is smaller than the window size,
+ * it will result in compression ratio degradation.
+ * NOTE 1: rsyncable mode only works when multithreading is enabled.
+ * NOTE 2: rsyncable performs poorly in combination with long range mode,
+ * since it will decrease the effectiveness of synchronization points,
+ * though mileage may vary.
+ * NOTE 3: Rsyncable mode limits maximum compression speed to ~400 MB/s.
+ * If the selected compression level is already running significantly slower,
+ * the overall speed won't be significantly impacted.
+ */
+ #define ZSTD_c_rsyncable ZSTD_c_experimentalParam1
+
+/* Select a compression format.
+ * The value must be of type ZSTD_format_e.
+ * See ZSTD_format_e enum definition for details */
+#define ZSTD_c_format ZSTD_c_experimentalParam2
+
+/* Force back-reference distances to remain < windowSize,
+ * even when referencing into Dictionary content (default:0) */
+#define ZSTD_c_forceMaxWindow ZSTD_c_experimentalParam3
+
+/* Controls whether the contents of a CDict
+ * are used in place, or copied into the working context.
+ * Accepts values from the ZSTD_dictAttachPref_e enum.
+ * See the comments on that enum for an explanation of the feature. */
+#define ZSTD_c_forceAttachDict ZSTD_c_experimentalParam4
+
+/* Controlled with ZSTD_paramSwitch_e enum.
+ * Default is ZSTD_ps_auto.
+ * Set to ZSTD_ps_disable to never compress literals.
+ * Set to ZSTD_ps_enable to always compress literals. (Note: uncompressed literals
+ * may still be emitted if huffman is not beneficial to use.)
+ *
+ * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
+ * literals compression based on the compression parameters - specifically,
+ * negative compression levels do not use literal compression.
+ */
+#define ZSTD_c_literalCompressionMode ZSTD_c_experimentalParam5
+
+/* Tries to fit compressed block size to be around targetCBlockSize.
+ * No target when targetCBlockSize == 0.
+ * There is no guarantee on compressed block size (default:0) */
+#define ZSTD_c_targetCBlockSize ZSTD_c_experimentalParam6
+
+/* User's best guess of source size.
+ * Hint is not valid when srcSizeHint == 0.
+ * There is no guarantee that hint is close to actual source size,
+ * but compression ratio may regress significantly if guess considerably underestimates */
+#define ZSTD_c_srcSizeHint ZSTD_c_experimentalParam7
+
+/* Controls whether the new and experimental "dedicated dictionary search
+ * structure" can be used. This feature is still rough around the edges, be
+ * prepared for surprising behavior!
+ *
+ * How to use it:
+ *
+ * When using a CDict, whether to use this feature or not is controlled at
+ * CDict creation, and it must be set in a CCtxParams set passed into that
+ * construction (via ZSTD_createCDict_advanced2()). A compression will then
+ * use the feature or not based on how the CDict was constructed; the value of
+ * this param, set in the CCtx, will have no effect.
+ *
+ * However, when a dictionary buffer is passed into a CCtx, such as via
+ * ZSTD_CCtx_loadDictionary(), this param can be set on the CCtx to control
+ * whether the CDict that is created internally can use the feature or not.
+ *
+ * What it does:
+ *
+ * Normally, the internal data structures of the CDict are analogous to what
+ * would be stored in a CCtx after compressing the contents of a dictionary.
+ * To an approximation, a compression using a dictionary can then use those
+ * data structures to simply continue what is effectively a streaming
+ * compression where the simulated compression of the dictionary left off.
+ * Which is to say, the search structures in the CDict are normally the same
+ * format as in the CCtx.
+ *
+ * It is possible to do better, since the CDict is not like a CCtx: the search
+ * structures are written once during CDict creation, and then are only read
+ * after that, while the search structures in the CCtx are both read and
+ * written as the compression goes along. This means we can choose a search
+ * structure for the dictionary that is read-optimized.
+ *
+ * This feature enables the use of that different structure.
+ *
+ * Note that some of the members of the ZSTD_compressionParameters struct have
+ * different semantics and constraints in the dedicated search structure. It is
+ * highly recommended that you simply set a compression level in the CCtxParams
+ * you pass into the CDict creation call, and avoid messing with the cParams
+ * directly.
+ *
+ * Effects:
+ *
+ * This will only have any effect when the selected ZSTD_strategy
+ * implementation supports this feature. Currently, that's limited to
+ * ZSTD_greedy, ZSTD_lazy, and ZSTD_lazy2.
+ *
+ * Note that this means that the CDict tables can no longer be copied into the
+ * CCtx, so the dict attachment mode ZSTD_dictForceCopy will no longer be
+ * usable. The dictionary can only be attached or reloaded.
+ *
+ * In general, you should expect compression to be faster--sometimes very much
+ * so--and CDict creation to be slightly slower. Eventually, we will probably
+ * make this mode the default.
+ */
+#define ZSTD_c_enableDedicatedDictSearch ZSTD_c_experimentalParam8
+
+/* ZSTD_c_stableInBuffer
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable.
+ *
+ * Tells the compressor that input data presented with ZSTD_inBuffer
+ * will ALWAYS be the same between calls.
+ * Technically, the @src pointer must never be changed,
+ * and the @pos field can only be updated by zstd.
+ * However, it's possible to increase the @size field,
+ * allowing scenarios where more data can be appended after compressions starts.
+ * These conditions are checked by the compressor,
+ * and compression will fail if they are not respected.
+ * Also, data in the ZSTD_inBuffer within the range [src, src + pos)
+ * MUST not be modified during compression or it will result in data corruption.
+ *
+ * When this flag is enabled zstd won't allocate an input window buffer,
+ * because the user guarantees it can reference the ZSTD_inBuffer until
+ * the frame is complete. But, it will still allocate an output buffer
+ * large enough to fit a block (see ZSTD_c_stableOutBuffer). This will also
+ * avoid the memcpy() from the input buffer to the input window buffer.
+ *
+ * NOTE: So long as the ZSTD_inBuffer always points to valid memory, using
+ * this flag is ALWAYS memory safe, and will never access out-of-bounds
+ * memory. However, compression WILL fail if conditions are not respected.
+ *
+ * WARNING: The data in the ZSTD_inBuffer in the range [src, src + pos) MUST
+ * not be modified during compression or it will result in data corruption.
+ * This is because zstd needs to reference data in the ZSTD_inBuffer to find
+ * matches. Normally zstd maintains its own window buffer for this purpose,
+ * but passing this flag tells zstd to rely on user provided buffer instead.
+ */
+#define ZSTD_c_stableInBuffer ZSTD_c_experimentalParam9
+
+/* ZSTD_c_stableOutBuffer
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable.
+ *
+ * Tells he compressor that the ZSTD_outBuffer will not be resized between
+ * calls. Specifically: (out.size - out.pos) will never grow. This gives the
+ * compressor the freedom to say: If the compressed data doesn't fit in the
+ * output buffer then return ZSTD_error_dstSizeTooSmall. This allows us to
+ * always decompress directly into the output buffer, instead of decompressing
+ * into an internal buffer and copying to the output buffer.
+ *
+ * When this flag is enabled zstd won't allocate an output buffer, because
+ * it can write directly to the ZSTD_outBuffer. It will still allocate the
+ * input window buffer (see ZSTD_c_stableInBuffer).
+ *
+ * Zstd will check that (out.size - out.pos) never grows and return an error
+ * if it does. While not strictly necessary, this should prevent surprises.
+ */
+#define ZSTD_c_stableOutBuffer ZSTD_c_experimentalParam10
+
+/* ZSTD_c_blockDelimiters
+ * Default is 0 == ZSTD_sf_noBlockDelimiters.
+ *
+ * For use with sequence compression API: ZSTD_compressSequences().
+ *
+ * Designates whether or not the given array of ZSTD_Sequence contains block delimiters
+ * and last literals, which are defined as sequences with offset == 0 and matchLength == 0.
+ * See the definition of ZSTD_Sequence for more specifics.
+ */
+#define ZSTD_c_blockDelimiters ZSTD_c_experimentalParam11
+
+/* ZSTD_c_validateSequences
+ * Default is 0 == disabled. Set to 1 to enable sequence validation.
+ *
+ * For use with sequence compression API: ZSTD_compressSequences().
+ * Designates whether or not we validate sequences provided to ZSTD_compressSequences()
+ * during function execution.
+ *
+ * Without validation, providing a sequence that does not conform to the zstd spec will cause
+ * undefined behavior, and may produce a corrupted block.
+ *
+ * With validation enabled, if sequence is invalid (see doc/zstd_compression_format.md for
+ * specifics regarding offset/matchlength requirements) then the function will bail out and
+ * return an error.
+ *
+ */
+#define ZSTD_c_validateSequences ZSTD_c_experimentalParam12
+
+/* ZSTD_c_useBlockSplitter
+ * Controlled with ZSTD_paramSwitch_e enum.
+ * Default is ZSTD_ps_auto.
+ * Set to ZSTD_ps_disable to never use block splitter.
+ * Set to ZSTD_ps_enable to always use block splitter.
+ *
+ * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
+ * block splitting based on the compression parameters.
+ */
+#define ZSTD_c_useBlockSplitter ZSTD_c_experimentalParam13
+
+/* ZSTD_c_useRowMatchFinder
+ * Controlled with ZSTD_paramSwitch_e enum.
+ * Default is ZSTD_ps_auto.
+ * Set to ZSTD_ps_disable to never use row-based matchfinder.
+ * Set to ZSTD_ps_enable to force usage of row-based matchfinder.
+ *
+ * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
+ * the row-based matchfinder based on support for SIMD instructions and the window log.
+ * Note that this only pertains to compression strategies: greedy, lazy, and lazy2
+ */
+#define ZSTD_c_useRowMatchFinder ZSTD_c_experimentalParam14
+
+/* ZSTD_c_deterministicRefPrefix
+ * Default is 0 == disabled. Set to 1 to enable.
+ *
+ * Zstd produces different results for prefix compression when the prefix is
+ * directly adjacent to the data about to be compressed vs. when it isn't.
+ * This is because zstd detects that the two buffers are contiguous and it can
+ * use a more efficient match finding algorithm. However, this produces different
+ * results than when the two buffers are non-contiguous. This flag forces zstd
+ * to always load the prefix in non-contiguous mode, even if it happens to be
+ * adjacent to the data, to guarantee determinism.
+ *
+ * If you really care about determinism when using a dictionary or prefix,
+ * like when doing delta compression, you should select this option. It comes
+ * at a speed penalty of about ~2.5% if the dictionary and data happened to be
+ * contiguous, and is free if they weren't contiguous. We don't expect that
+ * intentionally making the dictionary and data contiguous will be worth the
+ * cost to memcpy() the data.
+ */
+#define ZSTD_c_deterministicRefPrefix ZSTD_c_experimentalParam15
+
+/* ZSTD_c_prefetchCDictTables
+ * Controlled with ZSTD_paramSwitch_e enum. Default is ZSTD_ps_auto.
+ *
+ * In some situations, zstd uses CDict tables in-place rather than copying them
+ * into the working context. (See docs on ZSTD_dictAttachPref_e above for details).
+ * In such situations, compression speed is seriously impacted when CDict tables are
+ * "cold" (outside CPU cache). This parameter instructs zstd to prefetch CDict tables
+ * when they are used in-place.
+ *
+ * For sufficiently small inputs, the cost of the prefetch will outweigh the benefit.
+ * For sufficiently large inputs, zstd will by default memcpy() CDict tables
+ * into the working context, so there is no need to prefetch. This parameter is
+ * targeted at a middle range of input sizes, where a prefetch is cheap enough to be
+ * useful but memcpy() is too expensive. The exact range of input sizes where this
+ * makes sense is best determined by careful experimentation.
+ *
+ * Note: for this parameter, ZSTD_ps_auto is currently equivalent to ZSTD_ps_disable,
+ * but in the future zstd may conditionally enable this feature via an auto-detection
+ * heuristic for cold CDicts.
+ * Use ZSTD_ps_disable to opt out of prefetching under any circumstances.
+ */
+#define ZSTD_c_prefetchCDictTables ZSTD_c_experimentalParam16
+
+/* ZSTD_c_enableSeqProducerFallback
+ * Allowed values are 0 (disable) and 1 (enable). The default setting is 0.
+ *
+ * Controls whether zstd will fall back to an internal sequence producer if an
+ * external sequence producer is registered and returns an error code. This fallback
+ * is block-by-block: the internal sequence producer will only be called for blocks
+ * where the external sequence producer returns an error code. Fallback parsing will
+ * follow any other cParam settings, such as compression level, the same as in a
+ * normal (fully-internal) compression operation.
+ *
+ * The user is strongly encouraged to read the full Block-Level Sequence Producer API
+ * documentation (below) before setting this parameter. */
+#define ZSTD_c_enableSeqProducerFallback ZSTD_c_experimentalParam17
+
+/* ZSTD_c_maxBlockSize
+ * Allowed values are between 1KB and ZSTD_BLOCKSIZE_MAX (128KB).
+ * The default is ZSTD_BLOCKSIZE_MAX, and setting to 0 will set to the default.
+ *
+ * This parameter can be used to set an upper bound on the blocksize
+ * that overrides the default ZSTD_BLOCKSIZE_MAX. It cannot be used to set upper
+ * bounds greater than ZSTD_BLOCKSIZE_MAX or bounds lower than 1KB (will make
+ * compressBound() inaccurate). Only currently meant to be used for testing.
+ *
+ */
+#define ZSTD_c_maxBlockSize ZSTD_c_experimentalParam18
+
+/* ZSTD_c_searchForExternalRepcodes
+ * This parameter affects how zstd parses external sequences, such as sequences
+ * provided through the compressSequences() API or from an external block-level
+ * sequence producer.
+ *
+ * If set to ZSTD_ps_enable, the library will check for repeated offsets in
+ * external sequences, even if those repcodes are not explicitly indicated in
+ * the "rep" field. Note that this is the only way to exploit repcode matches
+ * while using compressSequences() or an external sequence producer, since zstd
+ * currently ignores the "rep" field of external sequences.
+ *
+ * If set to ZSTD_ps_disable, the library will not exploit repeated offsets in
+ * external sequences, regardless of whether the "rep" field has been set. This
+ * reduces sequence compression overhead by about 25% while sacrificing some
+ * compression ratio.
+ *
+ * The default value is ZSTD_ps_auto, for which the library will enable/disable
+ * based on compression level.
+ *
+ * Note: for now, this param only has an effect if ZSTD_c_blockDelimiters is
+ * set to ZSTD_sf_explicitBlockDelimiters. That may change in the future.
+ */
+#define ZSTD_c_searchForExternalRepcodes ZSTD_c_experimentalParam19
+
+/*! ZSTD_CCtx_getParameter() :
+ * Get the requested compression parameter value, selected by enum ZSTD_cParameter,
+ * and store it into int* value.
+ * @return : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_getParameter(const ZSTD_CCtx* cctx, ZSTD_cParameter param, int* value);
+
+
+/*! ZSTD_CCtx_params :
+ * Quick howto :
+ * - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
+ * - ZSTD_CCtxParams_setParameter() : Push parameters one by one into
+ * an existing ZSTD_CCtx_params structure.
+ * This is similar to
+ * ZSTD_CCtx_setParameter().
+ * - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
+ * an existing CCtx.
+ * These parameters will be applied to
+ * all subsequent frames.
+ * - ZSTD_compressStream2() : Do compression using the CCtx.
+ * - ZSTD_freeCCtxParams() : Free the memory, accept NULL pointer.
+ *
+ * This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
+ * for static allocation of CCtx for single-threaded compression.
+ */
+ZSTDLIB_STATIC_API ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
+ZSTDLIB_STATIC_API size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params); /* accept NULL pointer */
+
+/*! ZSTD_CCtxParams_reset() :
+ * Reset params to default values.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params);
+
+/*! ZSTD_CCtxParams_init() :
+ * Initializes the compression parameters of cctxParams according to
+ * compression level. All other parameters are reset to their default values.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel);
+
+/*! ZSTD_CCtxParams_init_advanced() :
+ * Initializes the compression and frame parameters of cctxParams according to
+ * params. All other parameters are reset to their default values.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
+
+/*! ZSTD_CCtxParams_setParameter() : Requires v1.4.0+
+ * Similar to ZSTD_CCtx_setParameter.
+ * Set one compression parameter, selected by enum ZSTD_cParameter.
+ * Parameters must be applied to a ZSTD_CCtx using
+ * ZSTD_CCtx_setParametersUsingCCtxParams().
+ * @result : a code representing success or failure (which can be tested with
+ * ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int value);
+
+/*! ZSTD_CCtxParams_getParameter() :
+ * Similar to ZSTD_CCtx_getParameter.
+ * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_getParameter(const ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
+
+/*! ZSTD_CCtx_setParametersUsingCCtxParams() :
+ * Apply a set of ZSTD_CCtx_params to the compression context.
+ * This can be done even after compression is started,
+ * if nbWorkers==0, this will have no impact until a new compression is started.
+ * if nbWorkers>=1, new parameters will be picked up at next job,
+ * with a few restrictions (windowLog, pledgedSrcSize, nbWorkers, jobSize, and overlapLog are not updated).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setParametersUsingCCtxParams(
+ ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params);
+
+/*! ZSTD_compressStream2_simpleArgs() :
+ * Same as ZSTD_compressStream2(),
+ * but using only integral types as arguments.
+ * This variant might be helpful for binders from dynamic languages
+ * which have troubles handling structures containing memory pointers.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_compressStream2_simpleArgs (
+ ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity, size_t* dstPos,
+ const void* src, size_t srcSize, size_t* srcPos,
+ ZSTD_EndDirective endOp);
+
+
+/***************************************
+* Advanced decompression functions
+***************************************/
+
+/*! ZSTD_isFrame() :
+ * Tells if the content of `buffer` starts with a valid Frame Identifier.
+ * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
+ * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
+ * Note 3 : Skippable Frame Identifiers are considered valid. */
+ZSTDLIB_STATIC_API unsigned ZSTD_isFrame(const void* buffer, size_t size);
+
+/*! ZSTD_createDDict_byReference() :
+ * Create a digested dictionary, ready to start decompression operation without startup delay.
+ * Dictionary content is referenced, and therefore stays in dictBuffer.
+ * It is important that dictBuffer outlives DDict,
+ * it must remain read accessible throughout the lifetime of DDict */
+ZSTDLIB_STATIC_API ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);
+
+/*! ZSTD_DCtx_loadDictionary_byReference() :
+ * Same as ZSTD_DCtx_loadDictionary(),
+ * but references `dict` content instead of copying it into `dctx`.
+ * This saves memory if `dict` remains around.,
+ * However, it's imperative that `dict` remains accessible (and unmodified) while being used, so it must outlive decompression. */
+ZSTDLIB_STATIC_API size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
+
+/*! ZSTD_DCtx_loadDictionary_advanced() :
+ * Same as ZSTD_DCtx_loadDictionary(),
+ * but gives direct control over
+ * how to load the dictionary (by copy ? by reference ?)
+ * and how to interpret it (automatic ? force raw mode ? full mode only ?). */
+ZSTDLIB_STATIC_API size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
+
+/*! ZSTD_DCtx_refPrefix_advanced() :
+ * Same as ZSTD_DCtx_refPrefix(), but gives finer control over
+ * how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) */
+ZSTDLIB_STATIC_API size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
+/*! ZSTD_DCtx_setMaxWindowSize() :
+ * Refuses allocating internal buffers for frames requiring a window size larger than provided limit.
+ * This protects a decoder context from reserving too much memory for itself (potential attack scenario).
+ * This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
+ * By default, a decompression context accepts all window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT)
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);
+
+/*! ZSTD_DCtx_getParameter() :
+ * Get the requested decompression parameter value, selected by enum ZSTD_dParameter,
+ * and store it into int* value.
+ * @return : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value);
+
+/* ZSTD_d_format
+ * experimental parameter,
+ * allowing selection between ZSTD_format_e input compression formats
+ */
+#define ZSTD_d_format ZSTD_d_experimentalParam1
+/* ZSTD_d_stableOutBuffer
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable.
+ *
+ * Tells the decompressor that the ZSTD_outBuffer will ALWAYS be the same
+ * between calls, except for the modifications that zstd makes to pos (the
+ * caller must not modify pos). This is checked by the decompressor, and
+ * decompression will fail if it ever changes. Therefore the ZSTD_outBuffer
+ * MUST be large enough to fit the entire decompressed frame. This will be
+ * checked when the frame content size is known. The data in the ZSTD_outBuffer
+ * in the range [dst, dst + pos) MUST not be modified during decompression
+ * or you will get data corruption.
+ *
+ * When this flag is enabled zstd won't allocate an output buffer, because
+ * it can write directly to the ZSTD_outBuffer, but it will still allocate
+ * an input buffer large enough to fit any compressed block. This will also
+ * avoid the memcpy() from the internal output buffer to the ZSTD_outBuffer.
+ * If you need to avoid the input buffer allocation use the buffer-less
+ * streaming API.
+ *
+ * NOTE: So long as the ZSTD_outBuffer always points to valid memory, using
+ * this flag is ALWAYS memory safe, and will never access out-of-bounds
+ * memory. However, decompression WILL fail if you violate the preconditions.
+ *
+ * WARNING: The data in the ZSTD_outBuffer in the range [dst, dst + pos) MUST
+ * not be modified during decompression or you will get data corruption. This
+ * is because zstd needs to reference data in the ZSTD_outBuffer to regenerate
+ * matches. Normally zstd maintains its own buffer for this purpose, but passing
+ * this flag tells zstd to use the user provided buffer.
+ */
+#define ZSTD_d_stableOutBuffer ZSTD_d_experimentalParam2
+
+/* ZSTD_d_forceIgnoreChecksum
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable
+ *
+ * Tells the decompressor to skip checksum validation during decompression, regardless
+ * of whether checksumming was specified during compression. This offers some
+ * slight performance benefits, and may be useful for debugging.
+ * Param has values of type ZSTD_forceIgnoreChecksum_e
+ */
+#define ZSTD_d_forceIgnoreChecksum ZSTD_d_experimentalParam3
+
+/* ZSTD_d_refMultipleDDicts
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable
+ *
+ * If enabled and dctx is allocated on the heap, then additional memory will be allocated
+ * to store references to multiple ZSTD_DDict. That is, multiple calls of ZSTD_refDDict()
+ * using a given ZSTD_DCtx, rather than overwriting the previous DDict reference, will instead
+ * store all references. At decompression time, the appropriate dictID is selected
+ * from the set of DDicts based on the dictID in the frame.
+ *
+ * Usage is simply calling ZSTD_refDDict() on multiple dict buffers.
+ *
+ * Param has values of byte ZSTD_refMultipleDDicts_e
+ *
+ * WARNING: Enabling this parameter and calling ZSTD_DCtx_refDDict(), will trigger memory
+ * allocation for the hash table. ZSTD_freeDCtx() also frees this memory.
+ * Memory is allocated as per ZSTD_DCtx::customMem.
+ *
+ * Although this function allocates memory for the table, the user is still responsible for
+ * memory management of the underlying ZSTD_DDict* themselves.
+ */
+#define ZSTD_d_refMultipleDDicts ZSTD_d_experimentalParam4
+
+/* ZSTD_d_disableHuffmanAssembly
+ * Set to 1 to disable the Huffman assembly implementation.
+ * The default value is 0, which allows zstd to use the Huffman assembly
+ * implementation if available.
+ *
+ * This parameter can be used to disable Huffman assembly at runtime.
+ * If you want to disable it at compile time you can define the macro
+ * ZSTD_DISABLE_ASM.
+ */
+#define ZSTD_d_disableHuffmanAssembly ZSTD_d_experimentalParam5
+
+
+/*! ZSTD_DCtx_setFormat() :
+ * This function is REDUNDANT. Prefer ZSTD_DCtx_setParameter().
+ * Instruct the decoder context about what kind of data to decode next.
+ * This instruction is mandatory to decode data without a fully-formed header,
+ * such ZSTD_f_zstd1_magicless for example.
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()). */
+ZSTD_DEPRECATED("use ZSTD_DCtx_setParameter() instead")
+ZSTDLIB_STATIC_API
+size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format);
+
+/*! ZSTD_decompressStream_simpleArgs() :
+ * Same as ZSTD_decompressStream(),
+ * but using only integral types as arguments.
+ * This can be helpful for binders from dynamic languages
+ * which have troubles handling structures containing memory pointers.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_decompressStream_simpleArgs (
+ ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity, size_t* dstPos,
+ const void* src, size_t srcSize, size_t* srcPos);
+
+
+/********************************************************************
+* Advanced streaming functions
+* Warning : most of these functions are now redundant with the Advanced API.
+* Once Advanced API reaches "stable" status,
+* redundant functions will be deprecated, and then at some point removed.
+********************************************************************/
+
+/*===== Advanced Streaming compression functions =====*/
+
+/*! ZSTD_initCStream_srcSize() :
+ * This function is DEPRECATED, and equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ *
+ * pledgedSrcSize must be correct. If it is not known at init time, use
+ * ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs,
+ * "0" also disables frame content size field. It may be enabled in the future.
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs,
+ int compressionLevel,
+ unsigned long long pledgedSrcSize);
+
+/*! ZSTD_initCStream_usingDict() :
+ * This function is DEPRECATED, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+ * ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+ *
+ * Creates of an internal CDict (incompatible with static CCtx), except if
+ * dict == NULL or dictSize < 8, in which case no dict is used.
+ * Note: dict is loaded with ZSTD_dct_auto (treated as a full zstd dictionary if
+ * it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs,
+ const void* dict, size_t dictSize,
+ int compressionLevel);
+
+/*! ZSTD_initCStream_advanced() :
+ * This function is DEPRECATED, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setParams(zcs, params);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+ *
+ * dict is loaded with ZSTD_dct_auto and ZSTD_dlm_byCopy.
+ * pledgedSrcSize must be correct.
+ * If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
+ const void* dict, size_t dictSize,
+ ZSTD_parameters params,
+ unsigned long long pledgedSrcSize);
+
+/*! ZSTD_initCStream_usingCDict() :
+ * This function is DEPRECATED, and equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_refCDict(zcs, cdict);
+ *
+ * note : cdict will just be referenced, and must outlive compression session
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset and ZSTD_CCtx_refCDict, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);
+
+/*! ZSTD_initCStream_usingCDict_advanced() :
+ * This function is DEPRECATED, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setFParams(zcs, fParams);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * ZSTD_CCtx_refCDict(zcs, cdict);
+ *
+ * same as ZSTD_initCStream_usingCDict(), with control over frame parameters.
+ * pledgedSrcSize must be correct. If srcSize is not known at init time, use
+ * value ZSTD_CONTENTSIZE_UNKNOWN.
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset and ZSTD_CCtx_refCDict, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
+ const ZSTD_CDict* cdict,
+ ZSTD_frameParameters fParams,
+ unsigned long long pledgedSrcSize);
+
+/*! ZSTD_resetCStream() :
+ * This function is DEPRECATED, and is equivalent to:
+ * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * Note: ZSTD_resetCStream() interprets pledgedSrcSize == 0 as ZSTD_CONTENTSIZE_UNKNOWN, but
+ * ZSTD_CCtx_setPledgedSrcSize() does not do the same, so ZSTD_CONTENTSIZE_UNKNOWN must be
+ * explicitly specified.
+ *
+ * start a new frame, using same parameters from previous frame.
+ * This is typically useful to skip dictionary loading stage, since it will re-use it in-place.
+ * Note that zcs must be init at least once before using ZSTD_resetCStream().
+ * If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN.
+ * If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
+ * For the time being, pledgedSrcSize==0 is interpreted as "srcSize unknown" for compatibility with older programs,
+ * but it will change to mean "empty" in future version, so use macro ZSTD_CONTENTSIZE_UNKNOWN instead.
+ * @return : 0, or an error code (which can be tested using ZSTD_isError())
+ * This prototype will generate compilation warnings.
+ */
+ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API
+size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);
+
+
+typedef struct {
+ unsigned long long ingested; /* nb input bytes read and buffered */
+ unsigned long long consumed; /* nb input bytes actually compressed */
+ unsigned long long produced; /* nb of compressed bytes generated and buffered */
+ unsigned long long flushed; /* nb of compressed bytes flushed : not provided; can be tracked from caller side */
+ unsigned currentJobID; /* MT only : latest started job nb */
+ unsigned nbActiveWorkers; /* MT only : nb of workers actively compressing at probe time */
+} ZSTD_frameProgression;
+
+/* ZSTD_getFrameProgression() :
+ * tells how much data has been ingested (read from input)
+ * consumed (input actually compressed) and produced (output) for current frame.
+ * Note : (ingested - consumed) is amount of input data buffered internally, not yet compressed.
+ * Aggregates progression inside active worker threads.
+ */
+ZSTDLIB_STATIC_API ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx);
+
+/*! ZSTD_toFlushNow() :
+ * Tell how many bytes are ready to be flushed immediately.
+ * Useful for multithreading scenarios (nbWorkers >= 1).
+ * Probe the oldest active job, defined as oldest job not yet entirely flushed,
+ * and check its output buffer.
+ * @return : amount of data stored in oldest job and ready to be flushed immediately.
+ * if @return == 0, it means either :
+ * + there is no active job (could be checked with ZSTD_frameProgression()), or
+ * + oldest job is still actively compressing data,
+ * but everything it has produced has also been flushed so far,
+ * therefore flush speed is limited by production speed of oldest job
+ * irrespective of the speed of concurrent (and newer) jobs.
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx);
+
+
+/*===== Advanced Streaming decompression functions =====*/
+
+/*!
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ * ZSTD_DCtx_loadDictionary(zds, dict, dictSize);
+ *
+ * note: no dictionary will be used if dict == NULL or dictSize < 8
+ */
+ZSTD_DEPRECATED("use ZSTD_DCtx_reset + ZSTD_DCtx_loadDictionary, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
+
+/*!
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ * ZSTD_DCtx_refDDict(zds, ddict);
+ *
+ * note : ddict is referenced, it must outlive decompression session
+ */
+ZSTD_DEPRECATED("use ZSTD_DCtx_reset + ZSTD_DCtx_refDDict, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);
+
+/*!
+ * This function is deprecated, and is equivalent to:
+ *
+ * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+ *
+ * re-use decompression parameters from previous init; saves dictionary loading
+ */
+ZSTD_DEPRECATED("use ZSTD_DCtx_reset, see zstd.h for detailed instructions")
+ZSTDLIB_STATIC_API size_t ZSTD_resetDStream(ZSTD_DStream* zds);
+
+
+/* ********************* BLOCK-LEVEL SEQUENCE PRODUCER API *********************
+ *
+ * *** OVERVIEW ***
+ * The Block-Level Sequence Producer API allows users to provide their own custom
+ * sequence producer which libzstd invokes to process each block. The produced list
+ * of sequences (literals and matches) is then post-processed by libzstd to produce
+ * valid compressed blocks.
+ *
+ * This block-level offload API is a more granular complement of the existing
+ * frame-level offload API compressSequences() (introduced in v1.5.1). It offers
+ * an easier migration story for applications already integrated with libzstd: the
+ * user application continues to invoke the same compression functions
+ * ZSTD_compress2() or ZSTD_compressStream2() as usual, and transparently benefits
+ * from the specific advantages of the external sequence producer. For example,
+ * the sequence producer could be tuned to take advantage of known characteristics
+ * of the input, to offer better speed / ratio, or could leverage hardware
+ * acceleration not available within libzstd itself.
+ *
+ * See contrib/externalSequenceProducer for an example program employing the
+ * Block-Level Sequence Producer API.
+ *
+ * *** USAGE ***
+ * The user is responsible for implementing a function of type
+ * ZSTD_sequenceProducer_F. For each block, zstd will pass the following
+ * arguments to the user-provided function:
+ *
+ * - sequenceProducerState: a pointer to a user-managed state for the sequence
+ * producer.
+ *
+ * - outSeqs, outSeqsCapacity: an output buffer for the sequence producer.
+ * outSeqsCapacity is guaranteed >= ZSTD_sequenceBound(srcSize). The memory
+ * backing outSeqs is managed by the CCtx.
+ *
+ * - src, srcSize: an input buffer for the sequence producer to parse.
+ * srcSize is guaranteed to be <= ZSTD_BLOCKSIZE_MAX.
+ *
+ * - dict, dictSize: a history buffer, which may be empty, which the sequence
+ * producer may reference as it parses the src buffer. Currently, zstd will
+ * always pass dictSize == 0 into external sequence producers, but this will
+ * change in the future.
+ *
+ * - compressionLevel: a signed integer representing the zstd compression level
+ * set by the user for the current operation. The sequence producer may choose
+ * to use this information to change its compression strategy and speed/ratio
+ * tradeoff. Note: the compression level does not reflect zstd parameters set
+ * through the advanced API.
+ *
+ * - windowSize: a size_t representing the maximum allowed offset for external
+ * sequences. Note that sequence offsets are sometimes allowed to exceed the
+ * windowSize if a dictionary is present, see doc/zstd_compression_format.md
+ * for details.
+ *
+ * The user-provided function shall return a size_t representing the number of
+ * sequences written to outSeqs. This return value will be treated as an error
+ * code if it is greater than outSeqsCapacity. The return value must be non-zero
+ * if srcSize is non-zero. The ZSTD_SEQUENCE_PRODUCER_ERROR macro is provided
+ * for convenience, but any value greater than outSeqsCapacity will be treated as
+ * an error code.
+ *
+ * If the user-provided function does not return an error code, the sequences
+ * written to outSeqs must be a valid parse of the src buffer. Data corruption may
+ * occur if the parse is not valid. A parse is defined to be valid if the
+ * following conditions hold:
+ * - The sum of matchLengths and literalLengths must equal srcSize.
+ * - All sequences in the parse, except for the final sequence, must have
+ * matchLength >= ZSTD_MINMATCH_MIN. The final sequence must have
+ * matchLength >= ZSTD_MINMATCH_MIN or matchLength == 0.
+ * - All offsets must respect the windowSize parameter as specified in
+ * doc/zstd_compression_format.md.
+ * - If the final sequence has matchLength == 0, it must also have offset == 0.
+ *
+ * zstd will only validate these conditions (and fail compression if they do not
+ * hold) if the ZSTD_c_validateSequences cParam is enabled. Note that sequence
+ * validation has a performance cost.
+ *
+ * If the user-provided function returns an error, zstd will either fall back
+ * to an internal sequence producer or fail the compression operation. The user can
+ * choose between the two behaviors by setting the ZSTD_c_enableSeqProducerFallback
+ * cParam. Fallback compression will follow any other cParam settings, such as
+ * compression level, the same as in a normal compression operation.
+ *
+ * The user shall instruct zstd to use a particular ZSTD_sequenceProducer_F
+ * function by calling
+ * ZSTD_registerSequenceProducer(cctx,
+ * sequenceProducerState,
+ * sequenceProducer)
+ * This setting will persist until the next parameter reset of the CCtx.
+ *
+ * The sequenceProducerState must be initialized by the user before calling
+ * ZSTD_registerSequenceProducer(). The user is responsible for destroying the
+ * sequenceProducerState.
+ *
+ * *** LIMITATIONS ***
+ * This API is compatible with all zstd compression APIs which respect advanced parameters.
+ * However, there are three limitations:
+ *
+ * First, the ZSTD_c_enableLongDistanceMatching cParam is not currently supported.
+ * COMPRESSION WILL FAIL if it is enabled and the user tries to compress with a block-level
+ * external sequence producer.
+ * - Note that ZSTD_c_enableLongDistanceMatching is auto-enabled by default in some
+ * cases (see its documentation for details). Users must explicitly set
+ * ZSTD_c_enableLongDistanceMatching to ZSTD_ps_disable in such cases if an external
+ * sequence producer is registered.
+ * - As of this writing, ZSTD_c_enableLongDistanceMatching is disabled by default
+ * whenever ZSTD_c_windowLog < 128MB, but that's subject to change. Users should
+ * check the docs on ZSTD_c_enableLongDistanceMatching whenever the Block-Level Sequence
+ * Producer API is used in conjunction with advanced settings (like ZSTD_c_windowLog).
+ *
+ * Second, history buffers are not currently supported. Concretely, zstd will always pass
+ * dictSize == 0 to the external sequence producer (for now). This has two implications:
+ * - Dictionaries are not currently supported. Compression will *not* fail if the user
+ * references a dictionary, but the dictionary won't have any effect.
+ * - Stream history is not currently supported. All advanced compression APIs, including
+ * streaming APIs, work with external sequence producers, but each block is treated as
+ * an independent chunk without history from previous blocks.
+ *
+ * Third, multi-threading within a single compression is not currently supported. In other words,
+ * COMPRESSION WILL FAIL if ZSTD_c_nbWorkers > 0 and an external sequence producer is registered.
+ * Multi-threading across compressions is fine: simply create one CCtx per thread.
+ *
+ * Long-term, we plan to overcome all three limitations. There is no technical blocker to
+ * overcoming them. It is purely a question of engineering effort.
+ */
+
+#define ZSTD_SEQUENCE_PRODUCER_ERROR ((size_t)(-1))
+
+typedef size_t ZSTD_sequenceProducer_F (
+ void* sequenceProducerState,
+ ZSTD_Sequence* outSeqs, size_t outSeqsCapacity,
+ const void* src, size_t srcSize,
+ const void* dict, size_t dictSize,
+ int compressionLevel,
+ size_t windowSize
+);
+
+/*! ZSTD_registerSequenceProducer() :
+ * Instruct zstd to use a block-level external sequence producer function.
+ *
+ * The sequenceProducerState must be initialized by the caller, and the caller is
+ * responsible for managing its lifetime. This parameter is sticky across
+ * compressions. It will remain set until the user explicitly resets compression
+ * parameters.
+ *
+ * Sequence producer registration is considered to be an "advanced parameter",
+ * part of the "advanced API". This means it will only have an effect on compression
+ * APIs which respect advanced parameters, such as compress2() and compressStream2().
+ * Older compression APIs such as compressCCtx(), which predate the introduction of
+ * "advanced parameters", will ignore any external sequence producer setting.
+ *
+ * The sequence producer can be "cleared" by registering a NULL function pointer. This
+ * removes all limitations described above in the "LIMITATIONS" section of the API docs.
+ *
+ * The user is strongly encouraged to read the full API documentation (above) before
+ * calling this function. */
+ZSTDLIB_STATIC_API void
+ZSTD_registerSequenceProducer(
+ ZSTD_CCtx* cctx,
+ void* sequenceProducerState,
+ ZSTD_sequenceProducer_F* sequenceProducer
+);
+
+
+/*********************************************************************
+* Buffer-less and synchronous inner streaming functions (DEPRECATED)
+*
+* This API is deprecated, and will be removed in a future version.
+* It allows streaming (de)compression with user allocated buffers.
+* However, it is hard to use, and not as well tested as the rest of
+* our API.
+*
+* Please use the normal streaming API instead: ZSTD_compressStream2,
+* and ZSTD_decompressStream.
+* If there is functionality that you need, but it doesn't provide,
+* please open an issue on our GitHub.
+********************************************************************* */
+
+/**
+ Buffer-less streaming compression (synchronous mode)
+
+ A ZSTD_CCtx object is required to track streaming operations.
+ Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource.
+ ZSTD_CCtx object can be re-used multiple times within successive compression operations.
+
+ Start by initializing a context.
+ Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression.
+
+ Then, consume your input using ZSTD_compressContinue().
+ There are some important considerations to keep in mind when using this advanced function :
+ - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffers only.
+ - Interface is synchronous : input is consumed entirely and produces 1+ compressed blocks.
+ - Caller must ensure there is enough space in `dst` to store compressed data under worst case scenario.
+ Worst case evaluation is provided by ZSTD_compressBound().
+ ZSTD_compressContinue() doesn't guarantee recover after a failed compression.
+ - ZSTD_compressContinue() presumes prior input ***is still accessible and unmodified*** (up to maximum distance size, see WindowLog).
+ It remembers all previous contiguous blocks, plus one separated memory segment (which can itself consists of multiple contiguous blocks)
+ - ZSTD_compressContinue() detects that prior input has been overwritten when `src` buffer overlaps.
+ In which case, it will "discard" the relevant memory section from its history.
+
+ Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
+ It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame.
+ Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders.
+
+ `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress again.
+*/
+
+/*===== Buffer-less streaming compression functions =====*/
+ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
+ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
+ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */
+
+ZSTD_DEPRECATED("This function will likely be removed in a future release. It is misleading and has very limited utility.")
+ZSTDLIB_STATIC_API
+size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**< note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */
+
+ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+
+/* The ZSTD_compressBegin_advanced() and ZSTD_compressBegin_usingCDict_advanced() are now DEPRECATED and will generate a compiler warning */
+ZSTD_DEPRECATED("use advanced API to access custom parameters")
+ZSTDLIB_STATIC_API
+size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize : If srcSize is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN */
+ZSTD_DEPRECATED("use advanced API to access custom parameters")
+ZSTDLIB_STATIC_API
+size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize); /* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */
+/**
+ Buffer-less streaming decompression (synchronous mode)
+
+ A ZSTD_DCtx object is required to track streaming operations.
+ Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
+ A ZSTD_DCtx object can be re-used multiple times.
+
+ First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader().
+ Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough.
+ Data fragment must be large enough to ensure successful decoding.
+ `ZSTD_frameHeaderSize_max` bytes is guaranteed to always be large enough.
+ result : 0 : successful decoding, the `ZSTD_frameHeader` structure is correctly filled.
+ >0 : `srcSize` is too small, please provide at least result bytes on next attempt.
+ errorCode, which can be tested using ZSTD_isError().
+
+ It fills a ZSTD_frameHeader structure with important information to correctly decode the frame,
+ such as the dictionary ID, content size, or maximum back-reference distance (`windowSize`).
+ Note that these values could be wrong, either because of data corruption, or because a 3rd party deliberately spoofs false information.
+ As a consequence, check that values remain within valid application range.
+ For example, do not allocate memory blindly, check that `windowSize` is within expectation.
+ Each application can set its own limits, depending on local restrictions.
+ For extended interoperability, it is recommended to support `windowSize` of at least 8 MB.
+
+ ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize` bytes.
+ ZSTD_decompressContinue() is very sensitive to contiguity,
+ if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
+ or that previous contiguous segment is large enough to properly handle maximum back-reference distance.
+ There are multiple ways to guarantee this condition.
+
+ The most memory efficient way is to use a round buffer of sufficient size.
+ Sufficient size is determined by invoking ZSTD_decodingBufferSize_min(),
+ which can return an error code if required value is too large for current system (in 32-bits mode).
+ In a round buffer methodology, ZSTD_decompressContinue() decompresses each block next to previous one,
+ up to the moment there is not enough room left in the buffer to guarantee decoding another full block,
+ which maximum size is provided in `ZSTD_frameHeader` structure, field `blockSizeMax`.
+ At which point, decoding can resume from the beginning of the buffer.
+ Note that already decoded data stored in the buffer should be flushed before being overwritten.
+
+ There are alternatives possible, for example using two or more buffers of size `windowSize` each, though they consume more memory.
+
+ Finally, if you control the compression process, you can also ignore all buffer size rules,
+ as long as the encoder and decoder progress in "lock-step",
+ aka use exactly the same buffer sizes, break contiguity at the same place, etc.
+
+ Once buffers are setup, start decompression, with ZSTD_decompressBegin().
+ If decompression requires a dictionary, use ZSTD_decompressBegin_usingDict() or ZSTD_decompressBegin_usingDDict().
+
+ Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
+ ZSTD_nextSrcSizeToDecompress() tells how many bytes to provide as 'srcSize' to ZSTD_decompressContinue().
+ ZSTD_decompressContinue() requires this _exact_ amount of bytes, or it will fail.
+
+ result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
+ It can be zero : it just means ZSTD_decompressContinue() has decoded some metadata item.
+ It can also be an error code, which can be tested with ZSTD_isError().
+
+ A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
+ Context can then be reset to start a new decompression.
+
+ Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
+ This information is not required to properly decode a frame.
+
+ == Special case : skippable frames ==
+
+ Skippable frames allow integration of user-defined data into a flow of concatenated frames.
+ Skippable frames will be ignored (skipped) by decompressor.
+ The format of skippable frames is as follows :
+ a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
+ b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
+ c) Frame Content - any content (User Data) of length equal to Frame Size
+ For skippable frames ZSTD_getFrameHeader() returns zfhPtr->frameType==ZSTD_skippableFrame.
+ For skippable frames ZSTD_decompressContinue() always returns 0 : it only skips the content.
+*/
+
+/*===== Buffer-less streaming decompression functions =====*/
+
+ZSTDLIB_STATIC_API size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize); /**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */
+
+ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
+ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
+ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
+
+ZSTDLIB_STATIC_API size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
+ZSTDLIB_STATIC_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+
+/* misc */
+ZSTD_DEPRECATED("This function will likely be removed in the next minor release. It is misleading and has very limited utility.")
+ZSTDLIB_STATIC_API void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
+typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
+ZSTDLIB_STATIC_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
+
+
+
+
+/* ========================================= */
+/** Block level API (DEPRECATED) */
+/* ========================================= */
+
+/*!
+
+ This API is deprecated in favor of the regular compression API.
+ You can get the frame header down to 2 bytes by setting:
+ - ZSTD_c_format = ZSTD_f_zstd1_magicless
+ - ZSTD_c_contentSizeFlag = 0
+ - ZSTD_c_checksumFlag = 0
+ - ZSTD_c_dictIDFlag = 0
+
+ This API is not as well tested as our normal API, so we recommend not using it.
+ We will be removing it in a future version. If the normal API doesn't provide
+ the functionality you need, please open a GitHub issue.
+
+ Block functions produce and decode raw zstd blocks, without frame metadata.
+ Frame metadata cost is typically ~12 bytes, which can be non-negligible for very small blocks (< 100 bytes).
+ But users will have to take in charge needed metadata to regenerate data, such as compressed and content sizes.
+
+ A few rules to respect :
+ - Compressing and decompressing require a context structure
+ + Use ZSTD_createCCtx() and ZSTD_createDCtx()
+ - It is necessary to init context before starting
+ + compression : any ZSTD_compressBegin*() variant, including with dictionary
+ + decompression : any ZSTD_decompressBegin*() variant, including with dictionary
+ - Block size is limited, it must be <= ZSTD_getBlockSize() <= ZSTD_BLOCKSIZE_MAX == 128 KB
+ + If input is larger than a block size, it's necessary to split input data into multiple blocks
+ + For inputs larger than a single block, consider using regular ZSTD_compress() instead.
+ Frame metadata is not that costly, and quickly becomes negligible as source size grows larger than a block.
+ - When a block is considered not compressible enough, ZSTD_compressBlock() result will be 0 (zero) !
+ ===> In which case, nothing is produced into `dst` !
+ + User __must__ test for such outcome and deal directly with uncompressed data
+ + A block cannot be declared incompressible if ZSTD_compressBlock() return value was != 0.
+ Doing so would mess up with statistics history, leading to potential data corruption.
+ + ZSTD_decompressBlock() _doesn't accept uncompressed data as input_ !!
+ + In case of multiple successive blocks, should some of them be uncompressed,
+ decoder must be informed of their existence in order to follow proper history.
+ Use ZSTD_insertBlock() for such a case.
+*/
+
+/*===== Raw zstd block functions =====*/
+ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_getBlockSize (const ZSTD_CCtx* cctx);
+ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_compressBlock (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
+ZSTDLIB_STATIC_API size_t ZSTD_insertBlock (ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize); /**< insert uncompressed block into `dctx` history. Useful for multi-blocks decompression. */
+
+#endif /* ZSTD_H_ZSTD_STATIC_LINKING_ONLY */
+
+#if defined (__cplusplus)
+}
+#endif
notaz.gp2x.de / pcsx_rearmed.git / blobdiff