+++ /dev/null
-/*
- * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
- * 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
-
-/* ====== Dependency ======*/
-#include <limits.h> /* INT_MAX */
-#include <stddef.h> /* size_t */
-
-
-/* ===== ZSTDLIB_API : control library symbols visibility ===== */
-#ifndef ZSTDLIB_VISIBILITY
-# if defined(__GNUC__) && (__GNUC__ >= 4)
-# define ZSTDLIB_VISIBILITY __attribute__ ((visibility ("default")))
-# else
-# define ZSTDLIB_VISIBILITY
-# endif
-#endif
-#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
-# define ZSTDLIB_API __declspec(dllexport) ZSTDLIB_VISIBILITY
-#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
-# define ZSTDLIB_API __declspec(dllimport) ZSTDLIB_VISIBILITY /* 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_VISIBILITY
-#endif
-
-
-/*******************************************************************************
- 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 4
-#define ZSTD_VERSION_RELEASE 5
-
-#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
-ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< to check runtime library version */
-
-#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)
-ZSTDLIB_API const char* ZSTD_versionString(void); /* requires v1.3.0+ */
-
-/* *************************************
- * 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`.
- * Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
- * @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. */
-ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
-
-/*! ZSTD_findFrameCompressedSize() :
- * `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 ======*/
-#define ZSTD_COMPRESSBOUND(srcSize) ((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 */
-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 */
-ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
-
-
-/***************************************
-* 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);
-
-/*! 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);
-
-/*! 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
-***************************************/
-
-/* 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 supercedes 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. */
- 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 useful if multi-threading is enabled (compiled with build macro ZSTD_MULTITHREAD).
- * They return an error otherwise. */
- ZSTD_c_nbWorkers=400, /* Select how many threads will be spawned to compress in parallel.
- * When nbWorkers >= 1, triggers asynchronous mode when used with ZSTD_compressStream*() :
- * ZSTD_compressStream*() consumes input and flush output if possible, but immediately gives back control to caller,
- * while compression work is performed in parallel, within worker threads.
- * (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, 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 1 MB, 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
- * 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_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 removes any reference to any dictionary too.
- * 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.
- * Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
- * @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
-***************************************/
-
-/* 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_c_format
- * 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_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);
-
-/*===== 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() :
- * 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.
- * - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
- * - When nbWorkers>=1, function is non-blocking : it just acquires a copy of input, and distributes jobs to internal worker threads, flush 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.
- * It can be replaced by ZSTD_CCtx_reset() and ZSTD_compressStream2().
- * It is redundant, but remains fully supported.
- * Advanced parameters and dictionary compression can only be used through the
- * new API.
- ******************************************************************************/
-
-/*!
- * 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);
- */
-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);
-
-/*===== Streaming decompression functions =====*/
-
-/* 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);
-
-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 dictBuilder/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(). */
-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() */
-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() :
- * 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_fromDDict() :
- * 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() :
- * 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 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
- *
- * This API allows dictionaries to be used with ZSTD_compress2(),
- * ZSTD_compressStream2(), and ZSTD_decompress(). Dictionaries are sticky, and
- * only reset with the context is reset with ZSTD_reset_parameters or
- * ZSTD_reset_session_and_parameters. Prefixes are single-use.
- ******************************************************************************/
-
-
-/*! ZSTD_CCtx_loadDictionary() :
- * 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.
- * To return to "no-dictionary" situation, load a NULL dictionary (or reset parameters).
- * 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. */
-ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
-
-/*! ZSTD_CCtx_refCDict() :
- * Reference a prepared dictionary, to be used for all next compressed frames.
- * Note that compression parameters are enforced from within CDict,
- * and supersede any compression parameter previously set within CCtx.
- * The parameters ignored are labled 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() :
- * 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).
- * @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() :
- * Create an internal DDict from dict buffer,
- * to be used to decompress next frames.
- * The dictionary remains valid for all future frames, until explicitly invalidated.
- * @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() :
- * Reference a prepared dictionary, to be used to decompress next frames.
- * The dictionary remains active for decompression of future frames using same DCtx.
- * @result : 0, or an error code (which can be tested with ZSTD_isError()).
- * Note 1 : Currently, only one dictionary can be managed.
- * Referencing a new dictionary effectively "discards" any previous one.
- * 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() :
- * 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_*() :
- * 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
-
-/****************************************************************************************
- * 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_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
-
-/* internal */
-#define ZSTD_HASHLOG3_MAX 17
-
-
-/* --- Advanced types --- */
-
-typedef struct ZSTD_CCtx_params_s ZSTD_CCtx_params;
-
-typedef struct {
- unsigned int matchPos; /* Match pos in dst */
- /* If seqDef.offset > 3, then this is seqDef.offset - 3
- * If seqDef.offset < 3, then this is the corresponding repeat offset
- * But if seqDef.offset < 3 and litLength == 0, this is the
- * repeat offset before the corresponding repeat offset
- * And if seqDef.offset == 3 and litLength == 0, this is the
- * most recent repeat offset - 1
- */
- unsigned int offset;
- unsigned int litLength; /* Literal length */
- unsigned int matchLength; /* Match length */
- /* 0 when seq not rep and seqDef.offset otherwise
- * when litLength == 0 this will be <= 4, otherwise <= 3 like normal
- */
- unsigned int rep;
-} 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 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;
-
-
-/***************************************
-* Frame 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_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 occured: 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_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_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
-
-/*! ZSTD_getSequences() :
- * Extract sequences from the sequence store
- * zc can be used to insert custom compression params.
- * This function invokes ZSTD_compress2
- * @return : number of sequences extracted
- */
-ZSTDLIB_API size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
- size_t outSeqsSize, const void* src, size_t srcSize);
-
-
-/***************************************
-* 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 budget large enough for any
- * compression level up to selected one. Unlike ZSTD_estimateCStreamSize*(),
- * this estimate does not include space for a window buffer, so this estimate
- * is guaranteed to be enough for single-shot compressions, but not streaming
- * compressions. It will however assume the input may be arbitrarily large,
- * which is the worst case. If srcSize is known to always be small,
- * ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
- * ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with
- * ZSTD_getCParams() to create cParams from compressionLevel.
- * ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with
- * ZSTD_CCtxParams_setParameter().
- *
- * Note: only single-threaded compression is supported. This function will
- * return an error code if ZSTD_c_nbWorkers is >= 1. */
-ZSTDLIB_API size_t ZSTD_estimateCCtxSize(int compressionLevel);
-ZSTDLIB_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
-ZSTDLIB_API size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
-ZSTDLIB_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 */
-ZSTDLIB_API size_t ZSTD_estimateCStreamSize(int compressionLevel);
-ZSTDLIB_API size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
-ZSTDLIB_API size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
-ZSTDLIB_API size_t ZSTD_estimateDStreamSize(size_t windowSize);
-ZSTDLIB_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_API size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
-ZSTDLIB_API size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
-ZSTDLIB_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_API ZSTD_CCtx* ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
-ZSTDLIB_API ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticCCtx() */
-
-ZSTDLIB_API ZSTD_DCtx* ZSTD_initStaticDCtx(void* workspace, size_t workspaceSize);
-ZSTDLIB_API ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticDCtx() */
-
-ZSTDLIB_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_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 ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL }; /**< this constant defers to stdlib's functions */
-
-ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
-
-ZSTDLIB_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);
-
-ZSTDLIB_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_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_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_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_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_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
-
-/*! 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 be marked as deprecated and generate compilation warning on reaching v1.5.x */
-ZSTDLIB_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 REDUNDANT.
- * It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_loadDictionary() and other parameter setters.
- * This prototype will be marked as deprecated and generate compilation warning in some future version */
-ZSTDLIB_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_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_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_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
-
-/* Controls how the literals are compressed (default is auto).
- * The value must be of type ZSTD_literalCompressionMode_e.
- * See ZSTD_literalCompressionMode_t enum definition for details.
- */
-#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
-
-/*! 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_API size_t ZSTD_CCtx_getParameter(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.
- *
- * This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
- * for static allocation of CCtx for single-threaded compression.
- */
-ZSTDLIB_API ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
-ZSTDLIB_API size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params);
-
-/*! ZSTD_CCtxParams_reset() :
- * Reset params to default values.
- */
-ZSTDLIB_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_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_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
-
-/*! ZSTD_CCtxParams_setParameter() :
- * 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 : 0, or an error code (which can be tested with ZSTD_isError()).
- */
-ZSTDLIB_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_API size_t ZSTD_CCtxParams_getParameter(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_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_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_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_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_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_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_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_API size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);
-
-/* ZSTD_d_format
- * experimental parameter,
- * allowing selection between ZSTD_format_e input compression formats
- */
-#define ZSTD_d_format ZSTD_d_experimentalParam1
-
-/*! ZSTD_DCtx_setFormat() :
- * 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()). */
-ZSTDLIB_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_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.
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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.
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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 approximately equivalent to:
- * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- * // Pseudocode: Set each zstd parameter and leave the rest as-is.
- * for ((param, value) : params) {
- * ZSTD_CCtx_setParameter(zcs, param, value);
- * }
- * 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.
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);
-
-/**! ZSTD_initCStream_usingCDict_advanced() :
- * This function is DEPRECATED, and is approximately equivalent to:
- * ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- * // Pseudocode: Set each zstd frame parameter and leave the rest as-is.
- * for ((fParam, value) : fParams) {
- * ZSTD_CCtx_setParameter(zcs, fParam, value);
- * }
- * 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.
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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);
- *
- * 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())
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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_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_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
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_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
- * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
- */
-ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds);
-
-
-/*********************************************************************
-* Buffer-less and synchronous inner streaming functions
-*
-* This is an advanced API, giving full control over buffer management, for users which need direct control over memory.
-* But it's also a complex one, with several restrictions, documented below.
-* Prefer normal streaming API for an easier experience.
-********************************************************************* */
-
-/**
- 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,
- or ZSTD_compressBegin_advanced(), for finer parameter control.
- It's also possible to duplicate a reference context which has already been initialized, using ZSTD_copyCCtx()
-
- 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 =====*/
-ZSTDLIB_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
-ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
-ZSTDLIB_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 */
-ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */
-ZSTDLIB_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 */
-ZSTDLIB_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 */
-
-ZSTDLIB_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-ZSTDLIB_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-
-
-/*-
- 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 =====*/
-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;
-} 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_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_API size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format);
-ZSTDLIB_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_API size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
-ZSTDLIB_API size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
-ZSTDLIB_API size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
-
-ZSTDLIB_API size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
-ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-
-/* misc */
-ZSTDLIB_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_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
-
-
-
-
-/* ============================ */
-/** Block level API */
-/* ============================ */
-
-/*!
- 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
- + copyCCtx() and copyDCtx() can be used too
- - 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 =====*/
-ZSTDLIB_API size_t ZSTD_getBlockSize (const ZSTD_CCtx* cctx);
-ZSTDLIB_API size_t ZSTD_compressBlock (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-ZSTDLIB_API size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-ZSTDLIB_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
projects / thirdparty / zstd.git / commitdiff
