2 * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
13 /* *************************************
15 ***************************************/
16 #define ZBUFF_STATIC_LINKING_ONLY
20 /*-***********************************************************
21 * Streaming compression
23 * A ZBUFF_CCtx object is required to track streaming operation.
24 * Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
25 * Use ZBUFF_compressInit() to start a new compression operation.
26 * ZBUFF_CCtx objects can be reused multiple times.
28 * Use ZBUFF_compressContinue() repetitively to consume your input.
29 * *srcSizePtr and *dstCapacityPtr can be any size.
30 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
31 * 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.
32 * The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
33 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
34 * or an error code, which can be tested using ZBUFF_isError().
36 * ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
37 * Note that it will not output more than *dstCapacityPtr.
38 * Therefore, some content might still be left into its internal buffer if dst buffer is too small.
39 * @return : nb of bytes still present into internal buffer (0 if it's empty)
40 * or an error code, which can be tested using ZBUFF_isError().
42 * ZBUFF_compressEnd() instructs to finish a frame.
43 * It will perform a flush and write frame epilogue.
44 * Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
45 * @return : nb of bytes still present into internal buffer (0 if it's empty)
46 * or an error code, which can be tested using ZBUFF_isError().
48 * Hint : recommended buffer sizes (not compulsory)
49 * input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
50 * 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.
51 * ***********************************************************/
53 ZBUFF_CCtx* ZBUFF_createCCtx(void)
55 return ZSTD_createCStream();
58 ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)
60 return ZSTD_createCStream_advanced(customMem);
63 size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)
65 return ZSTD_freeCStream(zbc);
69 /* ====== Initialization ====== */
71 size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
72 const void* dict, size_t dictSize,
73 ZSTD_parameters params, unsigned long long pledgedSrcSize)
75 if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN; /* preserve "0 == unknown" behavior */
76 return ZSTD_initCStream_advanced(zbc, dict, dictSize, params, pledgedSrcSize);
80 size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
82 return ZSTD_initCStream_usingDict(zbc, dict, dictSize, compressionLevel);
85 size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)
87 return ZSTD_initCStream(zbc, compressionLevel);
90 /* ====== Compression ====== */
93 size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
94 void* dst, size_t* dstCapacityPtr,
95 const void* src, size_t* srcSizePtr)
98 ZSTD_outBuffer outBuff;
102 outBuff.size = *dstCapacityPtr;
105 inBuff.size = *srcSizePtr;
106 result = ZSTD_compressStream(zbc, &outBuff, &inBuff);
107 *dstCapacityPtr = outBuff.pos;
108 *srcSizePtr = inBuff.pos;
114 /* ====== Finalize ====== */
116 size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
119 ZSTD_outBuffer outBuff;
122 outBuff.size = *dstCapacityPtr;
123 result = ZSTD_flushStream(zbc, &outBuff);
124 *dstCapacityPtr = outBuff.pos;
129 size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
132 ZSTD_outBuffer outBuff;
135 outBuff.size = *dstCapacityPtr;
136 result = ZSTD_endStream(zbc, &outBuff);
137 *dstCapacityPtr = outBuff.pos;
143 /* *************************************
145 ***************************************/
146 size_t ZBUFF_recommendedCInSize(void) { return ZSTD_CStreamInSize(); }
147 size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_CStreamOutSize(); }