diff options
Diffstat (limited to 'vendor/github.com/DataDog/zstd/zbuff_compress.c')
-rw-r--r-- | vendor/github.com/DataDog/zstd/zbuff_compress.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/vendor/github.com/DataDog/zstd/zbuff_compress.c b/vendor/github.com/DataDog/zstd/zbuff_compress.c new file mode 100644 index 000000000..f39c60d89 --- /dev/null +++ b/vendor/github.com/DataDog/zstd/zbuff_compress.c @@ -0,0 +1,147 @@ +/* + * 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(); } |