--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/python-zstandard/zstd/zstd.h Thu Nov 10 21:45:29 2016 -0800
@@ -0,0 +1,640 @@
+/*
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#ifndef ZSTD_H_235446
+#define ZSTD_H_235446
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/* ====== Dependency ======*/
+#include <stddef.h> /* size_t */
+
+
+/* ====== Export for Windows ======*/
+/*
+* ZSTD_DLL_EXPORT :
+* Enable exporting of functions when building a Windows DLL
+*/
+#if defined(_WIN32) && defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
+# define ZSTDLIB_API __declspec(dllexport)
+#else
+# define ZSTDLIB_API
+#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 compression levels from 1 up to ZSTD_maxCLevel() which is 22.
+ Levels >= 20, labelled `--ultra`, should be used with caution, as they require more memory.
+ Compression can be done in:
+ - a single step (described as Simple API)
+ - a single step, reusing a context (described as Explicit memory management)
+ - unbounded multiple steps (described as Streaming compression)
+ The compression ratio achievable on small data can be highly improved using compression with a dictionary in:
+ - a single step (described as Simple dictionary API)
+ - a single step, reusing a dictionary (described as Fast dictionary API)
+
+ Advanced experimental functions can be accessed using #define ZSTD_STATIC_LINKING_ONLY before including zstd.h.
+ These APIs shall never be used with a dynamic library.
+ They are not "stable", their definition may change in the future. Only static linking is allowed.
+*********************************************************************************************************/
+
+/*------ Version ------*/
+ZSTDLIB_API unsigned ZSTD_versionNumber (void); /**< returns version number of ZSTD */
+
+#define ZSTD_VERSION_MAJOR 1
+#define ZSTD_VERSION_MINOR 1
+#define ZSTD_VERSION_RELEASE 1
+
+#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)
+
+#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
+
+
+/***************************************
+* 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 a single compressed frame.
+ `dstCapacity` is an upper bound of originalSize.
+ 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_getDecompressedSize() :
+* 'src' is the start of a zstd compressed frame.
+* @return : content size to be decompressed, as a 64-bits value _if known_, 0 otherwise.
+* note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
+* When `return==0`, data to decompress could be any size.
+* In which case, it's necessary to use streaming mode to decompress data.
+* Optionally, application can still use ZSTD_decompress() while relying on implied limits.
+* (For example, data may be necessarily cut into blocks <= 16 KB).
+* 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 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. */
+ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
+
+
+/*====== Helper functions ======*/
+ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
+ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case 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 */
+
+
+/***************************************
+* Explicit memory management
+***************************************/
+/*= Compression context
+* When compressing many messages / blocks,
+* it is recommended to allocate a context just once, and re-use it for each successive compression operation.
+* This will make the situation much easier for the system's memory.
+* Use one context per thread for parallel execution in multi-threaded environments. */
+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(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()) */
+ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel);
+
+/*= Decompression context */
+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 (see ZSTD_createDCtx()) */
+ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+
+
+/**************************
+* Simple dictionary API
+***************************/
+/*! ZSTD_compress_usingDict() :
+* Compression using a predefined Dictionary (see dictBuilder/zdict.h).
+* Note : This function load the dictionary, resulting in significant startup delay. */
+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 predefined Dictionary (see dictBuilder/zdict.h).
+* Dictionary must be identical to the one used during compression.
+* Note : This function load the dictionary, resulting in significant startup delay */
+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);
+
+
+/****************************
+* Fast dictionary API
+****************************/
+typedef struct ZSTD_CDict_s ZSTD_CDict;
+
+/*! ZSTD_createCDict() :
+* When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+* ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+* ZSTD_CDict can be created once and used by multiple threads concurrently, as its usage is read-only.
+* `dict` can be released after ZSTD_CDict creation */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dict, 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.
+* Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
+* Note that compression level is decided during dictionary creation */
+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.
+* `dict` can be released after creation */
+ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dict, 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
+* Faster startup than ZSTD_decompress_usingDict(), 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);
+
+
+/****************************
+* 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 in situations where many streaming operations will be achieved consecutively,
+* since it will play nicer with system's memory, by re-using already allocated memory.
+* Use one separate ZSTD_CStream per thread for parallel execution.
+*
+* Start a new compression by initializing ZSTD_CStream.
+* Use ZSTD_initCStream() to start a new compression operation.
+* Use ZSTD_initCStream_usingDict() for a compression which requires a dictionary.
+*
+* Use ZSTD_compressStream() repetitively to consume input stream.
+* The function will automatically update both `pos` fields.
+* Note that it may not consume the entire input, in which case `pos < size`,
+* and it's up to the caller to present again remaining data.
+* @return : a size hint, preferred nb of bytes to use as input for next function call
+* (it's just a hint, to help latency a little, any other value will work fine)
+* (note : the size hint is guaranteed to be <= ZSTD_CStreamInSize() )
+* or an error code, which can be tested using ZSTD_isError().
+*
+* At any moment, it's possible to flush whatever data remains within buffer, using ZSTD_flushStream().
+* `output->pos` will be updated.
+* Note some content might still be left within internal buffer if `output->size` is too small.
+* @return : nb of bytes still present within internal buffer (0 if it's empty)
+* or an error code, which can be tested using ZSTD_isError().
+*
+* ZSTD_endStream() 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.
+* Similar to ZSTD_flushStream(), it may not be able to flush the full content if `output->size` is too small.
+* In which case, call again ZSTD_endStream() to complete the flush.
+* @return : nb of bytes still present within internal buffer (0 if it's empty)
+* or an error code, which can be tested using ZSTD_isError().
+*
+* *******************************************************************/
+
+/*===== Streaming compression functions ======*/
+typedef struct ZSTD_CStream_s ZSTD_CStream;
+ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
+ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
+ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
+ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
+ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
+
+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 in all circumstances. */
+
+
+
+/*-***************************************************************************
+* 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,
+* or ZSTD_initDStream_usingDict() if decompression requires a dictionary.
+* @return : recommended first input size
+*
+* 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.
+* If `output.pos < output.size`, decoder has flushed everything it could.
+* @return : 0 when a frame is completely decoded and fully flushed,
+* an error code, which can be tested using ZSTD_isError(),
+* any other value > 0, which means there is still some work to do to complete the frame.
+* The return value is a suggested next input size (just an hint, to help latency).
+* *******************************************************************************/
+
+/*===== Streaming decompression functions =====*/
+typedef struct ZSTD_DStream_s ZSTD_DStream;
+ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
+ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
+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. */
+
+
+
+#ifdef ZSTD_STATIC_LINKING_ONLY
+
+/****************************************************************************************
+ * START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
+ * The definitions in this section are considered experimental.
+ * They should never be used with a dynamic library, as they may change in the future.
+ * They are provided for advanced usages.
+ * Use them only in association with static linking.
+ * ***************************************************************************************/
+
+/* --- Constants ---*/
+#define ZSTD_MAGICNUMBER 0xFD2FB528 /* v0.8 */
+#define ZSTD_MAGIC_SKIPPABLE_START 0x184D2A50U
+
+#define ZSTD_WINDOWLOG_MAX_32 25
+#define ZSTD_WINDOWLOG_MAX_64 27
+#define ZSTD_WINDOWLOG_MAX ((U32)(MEM_32bits() ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
+#define ZSTD_WINDOWLOG_MIN 10
+#define ZSTD_HASHLOG_MAX ZSTD_WINDOWLOG_MAX
+#define ZSTD_HASHLOG_MIN 6
+#define ZSTD_CHAINLOG_MAX (ZSTD_WINDOWLOG_MAX+1)
+#define ZSTD_CHAINLOG_MIN ZSTD_HASHLOG_MIN
+#define ZSTD_HASHLOG3_MAX 17
+#define ZSTD_SEARCHLOG_MAX (ZSTD_WINDOWLOG_MAX-1)
+#define ZSTD_SEARCHLOG_MIN 1
+#define ZSTD_SEARCHLENGTH_MAX 7 /* only for ZSTD_fast, other strategies are limited to 6 */
+#define ZSTD_SEARCHLENGTH_MIN 3 /* only for ZSTD_btopt, other strategies are limited to 4 */
+#define ZSTD_TARGETLENGTH_MIN 4
+#define ZSTD_TARGETLENGTH_MAX 999
+
+#define ZSTD_FRAMEHEADERSIZE_MAX 18 /* for static allocation */
+static const size_t ZSTD_frameHeaderSize_prefix = 5;
+static const size_t ZSTD_frameHeaderSize_min = 6;
+static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
+static const size_t ZSTD_skippableHeaderSize = 8; /* magic number + skippable frame length */
+
+
+/*--- Advanced types ---*/
+typedef enum { ZSTD_fast, ZSTD_dfast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2, ZSTD_btlazy2, ZSTD_btopt, ZSTD_btopt2 } ZSTD_strategy; /* from faster to stronger */
+
+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 searchLength; /**< 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;
+} ZSTD_compressionParameters;
+
+typedef struct {
+ unsigned contentSizeFlag; /**< 1: content size will be in frame header (if known). */
+ unsigned checksumFlag; /**< 1: will generate a 22-bits checksum at end of frame, to be used for error detection by decompressor */
+ unsigned noDictIDFlag; /**< 1: no dict ID will be saved into frame header (if dictionary compression) */
+} ZSTD_frameParameters;
+
+typedef struct {
+ ZSTD_compressionParameters cParams;
+ ZSTD_frameParameters fParams;
+} ZSTD_parameters;
+
+/*= Custom memory allocation functions */
+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;
+
+
+/***************************************
+* Advanced compression functions
+***************************************/
+/*! ZSTD_estimateCCtxSize() :
+ * Gives the amount of memory allocated for a ZSTD_CCtx given a set of compression parameters.
+ * `frameContentSize` is an optional parameter, provide `0` if unknown */
+ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
+
+/*! ZSTD_createCCtx_advanced() :
+ * Create a ZSTD compression context using external alloc and free functions */
+ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
+
+/*! ZSTD_sizeofCCtx() :
+ * Gives the amount of memory used by a given ZSTD_CCtx */
+ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
+
+/*! ZSTD_createCDict_advanced() :
+ * Create a ZSTD_CDict using external alloc and free, and customized compression parameters */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
+ ZSTD_parameters params, ZSTD_customMem customMem);
+
+/*! ZSTD_sizeof_CDict() :
+ * Gives the amount of memory used by a given ZSTD_sizeof_CDict */
+ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
+
+/*! ZSTD_getParams() :
+* same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of a `ZSTD_compressionParameters`.
+* All fields of `ZSTD_frameParameters` are set to default (0) */
+ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSize, size_t dictSize);
+
+/*! ZSTD_getCParams() :
+* @return ZSTD_compressionParameters structure for a selected compression level and srcSize.
+* `srcSize` value is optional, select 0 if not known */
+ZSTDLIB_API ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSize, size_t dictSize);
+
+/*! ZSTD_checkCParams() :
+* Ensure param values remain within authorized range */
+ZSTDLIB_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
+
+/*! ZSTD_adjustCParams() :
+* optimize params for a given `srcSize` and `dictSize`.
+* both values are optional, select `0` if unknown. */
+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 of each compression parameter */
+ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize,
+ ZSTD_parameters params);
+
+
+/*--- Advanced decompression functions ---*/
+
+/*! ZSTD_estimateDCtxSize() :
+ * Gives the potential amount of memory allocated to create a ZSTD_DCtx */
+ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void);
+
+/*! ZSTD_createDCtx_advanced() :
+ * Create a ZSTD decompression context using external alloc and free functions */
+ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
+
+/*! ZSTD_sizeof_DCtx() :
+ * Gives the amount of memory used by a given ZSTD_DCtx */
+ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
+
+/*! ZSTD_sizeof_DDict() :
+ * Gives the amount of memory used by a given ZSTD_DDict */
+ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
+
+
+/********************************************************************
+* Advanced streaming functions
+********************************************************************/
+
+/*===== Advanced Streaming compression functions =====*/
+ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
+ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
+ZSTDLIB_API size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
+ ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize is optional and can be zero == unknown */
+ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict); /**< note : cdict will just be referenced, and must outlive compression session */
+ZSTDLIB_API size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize); /**< re-use compression parameters from previous init; skip dictionary loading stage; zcs must be init at least once before */
+ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+
+
+/*===== Advanced Streaming decompression functions =====*/
+typedef enum { ZSTDdsp_maxWindowSize } ZSTD_DStreamParameter_e;
+ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
+ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
+ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); /**< note : ddict will just be referenced, and must outlive decompression session */
+ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds); /**< re-use decompression parameters from previous init; saves dictionary loading */
+ZSTDLIB_API size_t ZSTD_sizeof_DStream(const 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 many restrictions (documented below).
+* Prefer using 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 buffer only.
+ - Interface is synchronous : input is consumed entirely and produce 1+ (or more) 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 a NULL,0 src content, in which case, it will write a final empty block to end the frame,
+ Without last block mark, frames will be considered unfinished (broken) by decoders.
+
+ You can then reuse `ZSTD_CCtx` (ZSTD_compressBegin()) to compress some new frame.
+*/
+
+/*===== 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);
+ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize);
+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_getFrameParams().
+ It fills a ZSTD_frameParams structure which provide important information to correctly decode the frame,
+ such as the minimum rolling buffer size to allocate to decompress data (`windowSize`),
+ and the dictionary ID used.
+ (Note : content size is optional, it may not be present. 0 means : content size unknown).
+ Note that these values could be wrong, either because of data malformation, or because an attacker is spoofing deliberate false information.
+ As a consequence, check that values remain within valid application range, especially `windowSize`, before allocation.
+ Each application can set its own limit, depending on local restrictions. For extended interoperability, it is recommended to support at least 8 MB.
+ Frame parameters are extracted from the beginning of the compressed frame.
+ Data fragment must be large enough to ensure successful decoding, typically `ZSTD_frameHeaderSize_max` bytes.
+ @result : 0 : successful decoding, the `ZSTD_frameParams` 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().
+
+ Start decompression, with ZSTD_decompressBegin() or ZSTD_decompressBegin_usingDict().
+ Alternatively, you can copy a prepared context, using ZSTD_copyDCtx().
+
+ 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, which is not an error; it just means ZSTD_decompressContinue() has decoded some metadata item.
+ It can also be an error code, which can be tested with ZSTD_isError().
+
+ ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize`.
+ They should preferably be located contiguously, prior to current block.
+ Alternatively, a round buffer of sufficient size is also possible. Sufficient size is determined by frame parameters.
+ 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.
+
+ 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 a 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_decompressContinue() always returns 0.
+ For skippable frames ZSTD_getFrameParams() returns fparamsPtr->windowLog==0 what means that a frame is skippable.
+ It also returns Frame Size as fparamsPtr->frameContentSize.
+*/
+
+typedef struct {
+ unsigned long long frameContentSize;
+ unsigned windowSize;
+ unsigned dictID;
+ unsigned checksumFlag;
+} ZSTD_frameParams;
+
+/*===== Buffer-less streaming decompression functions =====*/
+ZSTDLIB_API size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input, see details below */
+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 void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
+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);
+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 functions
+
+ 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 : ZSTD_compressBegin()
+ + decompression : ZSTD_decompressBegin()
+ + variants _usingDict() are also allowed
+ + copyCCtx() and copyDCtx() work too
+ - Block size is limited, it must be <= ZSTD_getBlockSizeMax()
+ + If you need to compress more, cut data into multiple blocks
+ + Consider using the regular ZSTD_compress() instead, as frame metadata costs become negligible when source size is large.
+ - 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, decoder must be informed of uncompressed block existence to follow proper history.
+ Use ZSTD_insertBlock() in such a case.
+*/
+
+#define ZSTD_BLOCKSIZE_ABSOLUTEMAX (128 * 1024) /* define, for static allocation */
+/*===== Raw zstd block functions =====*/
+ZSTDLIB_API size_t ZSTD_getBlockSizeMax(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 block into `dctx` history. Useful for uncompressed blocks */
+
+
+#endif /* ZSTD_STATIC_LINKING_ONLY */
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* ZSTD_H_235446 */