WIP [VOL-2811] - Incorporate preliminary onu-adapter-go code into opencord repo
- reason "discovery-mibsync-complete" reached (via full MibUpload only, received data won't be stored yet)
- first review comments of patchset #4 considered
(please have a look into our inline-comments in Gerrit to know more about the current state)
- no refactoring done yet
Change-Id: Iac47817f8ce4bd28dd8132f530b0570d57ae99b8
Signed-off-by: Holger Hildebrandt <holger.hildebrandt@adtran.com>
diff --git a/vendor/github.com/DataDog/zstd/zstd.h b/vendor/github.com/DataDog/zstd/zstd.h
new file mode 100644
index 0000000..a1910ee
--- /dev/null
+++ b/vendor/github.com/DataDog/zstd/zstd.h
@@ -0,0 +1,1945 @@
+/*
+ * Copyright (c) 2016-present, 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 <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 1
+
+#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
+ * The function will compress at requested compression level,
+ * ignoring any other parameter */
+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, /* Update all compression parameters according to pre-defined cLevel table
+ * 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 sets all default values of other compression parameters */
+ ZSTD_c_windowLog=101, /* Maximum allowed back-reference distance, expressed as power of 2.
+ * 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 window size at decompression stage if using streaming. */
+ 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 when using "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 when using "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 variants, 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
+ * 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_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_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 / blocks using the same dictionary, it's recommended to load it only once.
+ * ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without 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.
+ * Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate `dictBuffer` content.
+ * Note : A ZSTD_CDict can be created from an empty dictBuffer, but it is inefficient when used to compress small data. */
+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_dm_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_dm_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 5 /* minimum input size required to query frame header size */
+#define ZSTD_FRAMEHEADERSIZE_MIN 6
+#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
+
+/* internal */
+#define ZSTD_HASHLOG3_MAX 17
+
+
+/* --- Advanced types --- */
+
+typedef struct ZSTD_CCtx_params_s ZSTD_CCtx_params;
+
+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 {
+ /* Opened question : should we have a format ZSTD_f_auto ?
+ * Today, it would mean exactly the same as ZSTD_f_zstd1.
+ * But, in the future, should several formats become supported,
+ * on the compression side, it would mean "default format".
+ * On the decompression side, it would mean "automatic format detection",
+ * so that ZSTD_f_zstd1 would mean "accept *only* zstd frames".
+ * Since meaning is a little different, another option could be to define different enums for compression and decompression.
+ * This question could be kept for later, when there are actually multiple formats to support,
+ * but there is also the question of pinning enum values, and pinning value `0` is especially important */
+ 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 two 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.
+ *
+ * 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_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);
+
+
+/***************************************
+* 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.
+ * It will also consider src size to be arbitrarily "large", which is 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(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
+ * Note : CCtx size estimation is only correct for single-threaded compression. */
+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. */
+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() :
+ * Same as ZSTD_compress_usingDict(), with fine-tune control over compression parameters (by structure) */
+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() :
+ * Same as ZSTD_compress_usingCDict(), with fine-tune control over frame parameters */
+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
+
+/*! 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.
+ */
+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_dm_auto (treated as a full zstd dictionary if
+ * it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
+ */
+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);
+ * ZSTD_CCtx_setZstdParams(zcs, params); // Set the zstd params and leave the rest as-is
+ * ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+ * ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+ *
+ * pledgedSrcSize must be correct. If srcSize is not known at init time, use
+ * value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy.
+ */
+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
+ */
+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);
+ * ZSTD_CCtx_setZstdFrameParams(zcs, fParams); // Set the zstd frame params and leave the rest as-is
+ * 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.
+ */
+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())
+ */
+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
+ */
+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
+ */
+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
+ */
+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 ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
+ User will have to take in charge required information 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, really consider using regular ZSTD_compress() instead.
+ Frame metadata is not that costly, and quickly becomes negligible as source size grows larger.
+ - When a block is considered not compressible enough, ZSTD_compressBlock() result will be zero.
+ In which case, nothing is produced into `dst` !
+ + User must test for such outcome and deal directly with uncompressed data
+ + 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