Takahiro Suzuki | d7bf820 | 2020-12-17 20:21:59 +0900 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. |
| 3 | * All rights reserved. |
| 4 | * |
| 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. |
| 9 | */ |
| 10 | |
| 11 | #ifndef ZSTD_V04_H_91868324769238 |
| 12 | #define ZSTD_V04_H_91868324769238 |
| 13 | |
| 14 | #if defined (__cplusplus) |
| 15 | extern "C" { |
| 16 | #endif |
| 17 | |
| 18 | /* ************************************* |
| 19 | * Includes |
| 20 | ***************************************/ |
| 21 | #include <stddef.h> /* size_t */ |
| 22 | |
| 23 | |
| 24 | /* ************************************* |
| 25 | * Simple one-step function |
| 26 | ***************************************/ |
| 27 | /** |
| 28 | ZSTDv04_decompress() : decompress ZSTD frames compliant with v0.4.x format |
| 29 | compressedSize : is the exact source size |
| 30 | maxOriginalSize : is the size of the 'dst' buffer, which must be already allocated. |
| 31 | It must be equal or larger than originalSize, otherwise decompression will fail. |
| 32 | return : the number of bytes decompressed into destination buffer (originalSize) |
| 33 | or an errorCode if it fails (which can be tested using ZSTDv01_isError()) |
| 34 | */ |
| 35 | size_t ZSTDv04_decompress( void* dst, size_t maxOriginalSize, |
| 36 | const void* src, size_t compressedSize); |
| 37 | |
| 38 | /** |
| 39 | ZSTDv04_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.4.x format |
| 40 | srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' |
| 41 | cSize (output parameter) : the number of bytes that would be read to decompress this frame |
| 42 | or an error code if it fails (which can be tested using ZSTDv01_isError()) |
| 43 | dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame |
| 44 | or ZSTD_CONTENTSIZE_ERROR if an error occurs |
| 45 | |
| 46 | note : assumes `cSize` and `dBound` are _not_ NULL. |
| 47 | */ |
| 48 | void ZSTDv04_findFrameSizeInfoLegacy(const void *src, size_t srcSize, |
| 49 | size_t* cSize, unsigned long long* dBound); |
| 50 | |
| 51 | /** |
| 52 | ZSTDv04_isError() : tells if the result of ZSTDv04_decompress() is an error |
| 53 | */ |
| 54 | unsigned ZSTDv04_isError(size_t code); |
| 55 | |
| 56 | |
| 57 | /* ************************************* |
| 58 | * Advanced functions |
| 59 | ***************************************/ |
| 60 | typedef struct ZSTDv04_Dctx_s ZSTDv04_Dctx; |
| 61 | ZSTDv04_Dctx* ZSTDv04_createDCtx(void); |
| 62 | size_t ZSTDv04_freeDCtx(ZSTDv04_Dctx* dctx); |
| 63 | |
| 64 | size_t ZSTDv04_decompressDCtx(ZSTDv04_Dctx* dctx, |
| 65 | void* dst, size_t maxOriginalSize, |
| 66 | const void* src, size_t compressedSize); |
| 67 | |
| 68 | |
| 69 | /* ************************************* |
| 70 | * Direct Streaming |
| 71 | ***************************************/ |
| 72 | size_t ZSTDv04_resetDCtx(ZSTDv04_Dctx* dctx); |
| 73 | |
| 74 | size_t ZSTDv04_nextSrcSizeToDecompress(ZSTDv04_Dctx* dctx); |
| 75 | size_t ZSTDv04_decompressContinue(ZSTDv04_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize); |
| 76 | /** |
| 77 | Use above functions alternatively. |
| 78 | ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue(). |
| 79 | ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block. |
| 80 | Result is the number of bytes regenerated within 'dst'. |
| 81 | It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header. |
| 82 | */ |
| 83 | |
| 84 | |
| 85 | /* ************************************* |
| 86 | * Buffered Streaming |
| 87 | ***************************************/ |
| 88 | typedef struct ZBUFFv04_DCtx_s ZBUFFv04_DCtx; |
| 89 | ZBUFFv04_DCtx* ZBUFFv04_createDCtx(void); |
| 90 | size_t ZBUFFv04_freeDCtx(ZBUFFv04_DCtx* dctx); |
| 91 | |
| 92 | size_t ZBUFFv04_decompressInit(ZBUFFv04_DCtx* dctx); |
| 93 | size_t ZBUFFv04_decompressWithDictionary(ZBUFFv04_DCtx* dctx, const void* dict, size_t dictSize); |
| 94 | |
| 95 | size_t ZBUFFv04_decompressContinue(ZBUFFv04_DCtx* dctx, void* dst, size_t* maxDstSizePtr, const void* src, size_t* srcSizePtr); |
| 96 | |
| 97 | /** ************************************************ |
| 98 | * Streaming decompression |
| 99 | * |
| 100 | * A ZBUFF_DCtx object is required to track streaming operation. |
| 101 | * Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources. |
| 102 | * Use ZBUFF_decompressInit() to start a new decompression operation. |
| 103 | * ZBUFF_DCtx objects can be reused multiple times. |
| 104 | * |
| 105 | * Optionally, a reference to a static dictionary can be set, using ZBUFF_decompressWithDictionary() |
| 106 | * It must be the same content as the one set during compression phase. |
| 107 | * Dictionary content must remain accessible during the decompression process. |
| 108 | * |
| 109 | * Use ZBUFF_decompressContinue() repetitively to consume your input. |
| 110 | * *srcSizePtr and *maxDstSizePtr can be any size. |
| 111 | * The function will report how many bytes were read or written by modifying *srcSizePtr and *maxDstSizePtr. |
| 112 | * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. |
| 113 | * The content of dst will be overwritten (up to *maxDstSizePtr) at each function call, so save its content if it matters or change dst. |
| 114 | * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency) |
| 115 | * or 0 when a frame is completely decoded |
| 116 | * or an error code, which can be tested using ZBUFF_isError(). |
| 117 | * |
| 118 | * Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize / ZBUFF_recommendedDOutSize |
| 119 | * output : ZBUFF_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when it's decoded. |
| 120 | * input : ZBUFF_recommendedDInSize==128Kb+3; just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . |
| 121 | * **************************************************/ |
| 122 | unsigned ZBUFFv04_isError(size_t errorCode); |
| 123 | const char* ZBUFFv04_getErrorName(size_t errorCode); |
| 124 | |
| 125 | |
| 126 | /** The below functions provide recommended buffer sizes for Compression or Decompression operations. |
| 127 | * These sizes are not compulsory, they just tend to offer better latency */ |
| 128 | size_t ZBUFFv04_recommendedDInSize(void); |
| 129 | size_t ZBUFFv04_recommendedDOutSize(void); |
| 130 | |
| 131 | |
| 132 | /* ************************************* |
| 133 | * Prefix - version detection |
| 134 | ***************************************/ |
| 135 | #define ZSTDv04_magicNumber 0xFD2FB524 /* v0.4 */ |
| 136 | |
| 137 | |
| 138 | #if defined (__cplusplus) |
| 139 | } |
| 140 | #endif |
| 141 | |
| 142 | #endif /* ZSTD_V04_H_91868324769238 */ |