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- /*
- * 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.
- */
- /* *************************************
- * Dependencies
- ***************************************/
- #define ZBUFF_STATIC_LINKING_ONLY
- #include "zbuff.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 */
- return ZSTD_initCStream_advanced(zbc, dict, dictSize, params, pledgedSrcSize);
- }
- size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
- {
- return ZSTD_initCStream_usingDict(zbc, dict, dictSize, compressionLevel);
- }
- 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(); }
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