/**

 * 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.

 */

/* ***************************************************************

*  NOTES/WARNINGS

*****************************************************************/

/* The streaming API defined here will soon be deprecated by the

* new one in 'zstd.h'; consider migrating towards newer streaming

* API. See 'lib/README.md'.

*****************************************************************/

#ifndef ZSTD_BUFFERED_H_23987

#define ZSTD_BUFFERED_H_23987

#if defined (__cplusplus)

extern "C" {

#endif

/* *************************************

*  Dependencies

***************************************/

#include <stddef.h>      /* size_t */

/* ***************************************************************

*  Compiler specifics

*****************************************************************/

/* 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

/* *************************************

*  Streaming functions

***************************************/

/* This is the easier "buffered" streaming API,

*  using an internal buffer to lift all restrictions on user-provided buffers

*  which can be any size, any place, for both input and output.

*  ZBUFF and ZSTD are 100% interoperable,

*  frames created by one can be decoded by the other one */

typedef struct ZBUFF_CCtx_s ZBUFF_CCtx;

ZSTDLIB_API ZBUFF_CCtx* ZBUFF_createCCtx(void);

ZSTDLIB_API size_t      ZBUFF_freeCCtx(ZBUFF_CCtx* cctx);

ZSTDLIB_API size_t ZBUFF_compressInit(ZBUFF_CCtx* cctx, int compressionLevel);

ZSTDLIB_API size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);

ZSTDLIB_API size_t ZBUFF_compressContinue(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr);

ZSTDLIB_API size_t ZBUFF_compressFlush(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);

ZSTDLIB_API size_t ZBUFF_compressEnd(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);

/*-*************************************************

*  Streaming compression - howto

*

*  A ZBUFF_CCtx object is required to track streaming operation.

*  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.

*  ZBUFF_CCtx objects can be reused multiple times.

*

*  Start by initializing ZBUF_CCtx.

*  Use ZBUFF_compressInit() to start a new compression operation.

*  Use ZBUFF_compressInitDictionary() for a compression which requires a dictionary.

*

*  Use ZBUFF_compressContinue() repetitively to consume input stream.

*  *srcSizePtr and *dstCapacityPtr can be any size.

*  The function will report how many bytes were read or written within *srcSizePtr and *dstCapacityPtr.

*  Note that it may not consume the entire input, in which case it's up to the caller to present again remaining data.

*  The content of `dst` will be overwritten (up to *dstCapacityPtr) at each call, so save its content if it matters or change @dst .

*  @return : a hint to preferred nb of bytes to use as input for next function call (it's just a hint, to improve latency)

*            or an error code, which can be tested using ZBUFF_isError().

*

*  At any moment, it's possible to flush whatever data remains within buffer, using ZBUFF_compressFlush().

*  The nb of bytes written into `dst` will be reported into *dstCapacityPtr.

*  Note that the function cannot output more than *dstCapacityPtr,

*  therefore, some content might still be left into internal buffer if *dstCapacityPtr is too small.

*  @return : nb of bytes still present into internal buffer (0 if it's empty)

*            or an error code, which can be tested using ZBUFF_isError().

*

*  ZBUFF_compressEnd() 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 ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.

*  In which case, call again ZBUFF_compressFlush() to complete the flush.

*  @return : nb of bytes still present into internal buffer (0 if it's empty)

*            or an error code, which can be tested using ZBUFF_isError().

*

*  Hint : _recommended buffer_ sizes (not compulsory) : ZBUFF_recommendedCInSize() / ZBUFF_recommendedCOutSize()

*  input : ZBUFF_recommendedCInSize==128 KB block size is the internal unit, use this value to reduce intermediate stages (better latency)

*  output : ZBUFF_recommendedCOutSize==ZSTD_compressBound(128 KB) + 3 + 3 : ensures it's always possible to write/flush/end a full block. Skip some buffering.

*  By using both, it ensures that input will be entirely consumed, and output will always contain the result, reducing intermediate buffering.

* **************************************************/

typedef struct ZBUFF_DCtx_s ZBUFF_DCtx;

ZSTDLIB_API ZBUFF_DCtx* ZBUFF_createDCtx(void);

ZSTDLIB_API size_t      ZBUFF_freeDCtx(ZBUFF_DCtx* dctx);

ZSTDLIB_API size_t ZBUFF_decompressInit(ZBUFF_DCtx* dctx);

ZSTDLIB_API size_t ZBUFF_decompressInitDictionary(ZBUFF_DCtx* dctx, const void* dict, size_t dictSize);

ZSTDLIB_API size_t ZBUFF_decompressContinue(ZBUFF_DCtx* dctx,

                                            void* dst, size_t* dstCapacityPtr,

                                      const void* src, size_t* srcSizePtr);

/*-***************************************************************************

*  Streaming decompression howto

*

*  A ZBUFF_DCtx object is required to track streaming operations.

*  Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources.

*  Use ZBUFF_decompressInit() to start a new decompression operation,

*   or ZBUFF_decompressInitDictionary() if decompression requires a dictionary.

*  Note that ZBUFF_DCtx objects can be re-init multiple times.

*

*  Use ZBUFF_decompressContinue() repetitively to consume your input.

*  *srcSizePtr and *dstCapacityPtr can be any size.

*  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.

*  Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.

*  The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.

*  @return : 0 when a frame is completely decoded and fully flushed,

*            1 when there is still some data left within internal buffer to flush,

*            >1 when more data is expected, with value being a suggested next input size (it's just a hint, which helps latency),

*            or an error code, which can be tested using ZBUFF_isError().

*

*  Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize() and ZBUFF_recommendedDOutSize()

*  output : ZBUFF_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.

*  input  : ZBUFF_recommendedDInSize == 128KB + 3;

*           just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .

* *******************************************************************************/

/* *************************************

*  Tool functions

***************************************/

ZSTDLIB_API unsigned ZBUFF_isError(size_t errorCode);

ZSTDLIB_API const char* ZBUFF_getErrorName(size_t errorCode);

/** Functions below provide recommended buffer sizes for Compression or Decompression operations.

*   These sizes are just hints, they tend to offer better latency */

ZSTDLIB_API size_t ZBUFF_recommendedCInSize(void);

ZSTDLIB_API size_t ZBUFF_recommendedCOutSize(void);

ZSTDLIB_API size_t ZBUFF_recommendedDInSize(void);

ZSTDLIB_API size_t ZBUFF_recommendedDOutSize(void);

#ifdef ZBUFF_STATIC_LINKING_ONLY

/* ====================================================================================

 * The definitions in this section are considered experimental.

 * They should never be used in association 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.

 * ==================================================================================== */

/*--- Dependency ---*/

#define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_parameters, ZSTD_customMem */

#include "zstd.h"

/*--- Custom memory allocator ---*/

/*! ZBUFF_createCCtx_advanced() :

 *  Create a ZBUFF compression context using external alloc and free functions */

ZSTDLIB_API ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem);

/*! ZBUFF_createDCtx_advanced() :

 *  Create a ZBUFF decompression context using external alloc and free functions */

ZSTDLIB_API ZBUFF_DCtx* ZBUFF_createDCtx_advanced(ZSTD_customMem customMem);

/*--- Advanced Streaming Initialization ---*/

ZSTDLIB_API size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,

                                               const void* dict, size_t dictSize,

                                               ZSTD_parameters params, unsigned long long pledgedSrcSize);

#endif /* ZBUFF_STATIC_LINKING_ONLY */

#if defined (__cplusplus)

}

#endif

#endif  /* ZSTD_BUFFERED_H_23987 */