/*

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 * All rights reserved.

 *

 * This source code is licensed under both the BSD-style license (found in the

 * LICENSE file in the root directory of this source tree) and the GPLv2 (found

 * in the COPYING file in the root directory of this source tree).

 * You may select, at your option, one of the above-listed licenses.

 */

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

*  Dependencies

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

#define ZBUFF_STATIC_LINKING_ONLY

#include "zbuff.h"

#include "../common/error_private.h"

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

*  Streaming compression

*

*  A ZBUFF_CCtx object is required to track streaming operation.

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

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

*  ZBUFF_CCtx objects can be reused multiple times.

*

*  Use ZBUFF_compressContinue() 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 call again the function with remaining input.

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

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

*

*  ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.

*  Note that it will not output more than *dstCapacityPtr.

*  Therefore, some content might still be left into its internal buffer if dst buffer 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.

*  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content 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().

*

*  Hint : recommended buffer sizes (not compulsory)

*  input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.

*  output : ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize : ensures it's always possible to write/flush/end a full block at best speed.

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

ZBUFF_CCtx* ZBUFF_createCCtx(void)

{

    return ZSTD_createCStream();

}

ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)

{

    return ZSTD_createCStream_advanced(customMem);

}

size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)

{

    return ZSTD_freeCStream(zbc);

}

/* ======   Initialization   ====== */

size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,

                                   const void* dict, size_t dictSize,

                                   ZSTD_parameters params, unsigned long long pledgedSrcSize)

{

    if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* preserve "0 == unknown" behavior */

    FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setPledgedSrcSize(zbc, pledgedSrcSize), "");

    FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_windowLog, params.cParams.windowLog), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_hashLog, params.cParams.hashLog), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_chainLog, params.cParams.chainLog), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_searchLog, params.cParams.searchLog), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_minMatch, params.cParams.minMatch), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_targetLength, params.cParams.targetLength), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_strategy, params.cParams.strategy), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_contentSizeFlag, params.fParams.contentSizeFlag), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_checksumFlag, params.fParams.checksumFlag), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_dictIDFlag, params.fParams.noDictIDFlag), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");

    return 0;

}

size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)

{

    FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_compressionLevel, compressionLevel), "");

    FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");

    return 0;

}

size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)

{

    return ZSTD_initCStream(zbc, compressionLevel);

}

/* ======   Compression   ====== */

size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,

                              void* dst, size_t* dstCapacityPtr,

                        const void* src, size_t* srcSizePtr)

{

    size_t result;

    ZSTD_outBuffer outBuff;

    ZSTD_inBuffer inBuff;

    outBuff.dst = dst;

    outBuff.pos = 0;

    outBuff.size = *dstCapacityPtr;

    inBuff.src = src;

    inBuff.pos = 0;

    inBuff.size = *srcSizePtr;

    result = ZSTD_compressStream(zbc, &outBuff, &inBuff);

    *dstCapacityPtr = outBuff.pos;

    *srcSizePtr = inBuff.pos;

    return result;

}

/* ======   Finalize   ====== */

size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)

{

    size_t result;

    ZSTD_outBuffer outBuff;

    outBuff.dst = dst;

    outBuff.pos = 0;

    outBuff.size = *dstCapacityPtr;

    result = ZSTD_flushStream(zbc, &outBuff);

    *dstCapacityPtr = outBuff.pos;

    return result;

}

size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)

{

    size_t result;

    ZSTD_outBuffer outBuff;

    outBuff.dst = dst;

    outBuff.pos = 0;

    outBuff.size = *dstCapacityPtr;

    result = ZSTD_endStream(zbc, &outBuff);

    *dstCapacityPtr = outBuff.pos;

    return result;

}

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

*  Tool functions

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

size_t ZBUFF_recommendedCInSize(void)  { return ZSTD_CStreamInSize(); }

size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_CStreamOutSize(); }