Scott Baker | e7144bc | 2019-10-01 14:16:47 -0700 | [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 ZSTDv05_H |
| 12 | #define ZSTDv05_H |
| 13 | |
| 14 | #if defined (__cplusplus) |
| 15 | extern "C" { |
| 16 | #endif |
| 17 | |
| 18 | /*-************************************* |
| 19 | * Dependencies |
| 20 | ***************************************/ |
| 21 | #include <stddef.h> /* size_t */ |
| 22 | #include "mem.h" /* U64, U32 */ |
| 23 | |
| 24 | |
| 25 | /* ************************************* |
| 26 | * Simple functions |
| 27 | ***************************************/ |
| 28 | /*! ZSTDv05_decompress() : |
| 29 | `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail. |
| 30 | `dstCapacity` must be large enough, equal or larger than originalSize. |
| 31 | @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), |
| 32 | or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */ |
| 33 | size_t ZSTDv05_decompress( void* dst, size_t dstCapacity, |
| 34 | const void* src, size_t compressedSize); |
| 35 | |
| 36 | /** |
| 37 | ZSTDv05_getFrameSrcSize() : get the source length of a ZSTD frame |
| 38 | compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' |
| 39 | return : the number of bytes that would be read to decompress this frame |
| 40 | or an errorCode if it fails (which can be tested using ZSTDv05_isError()) |
| 41 | */ |
| 42 | size_t ZSTDv05_findFrameCompressedSize(const void* src, size_t compressedSize); |
| 43 | |
| 44 | /* ************************************* |
| 45 | * Helper functions |
| 46 | ***************************************/ |
| 47 | /* Error Management */ |
| 48 | unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ |
| 49 | const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */ |
| 50 | |
| 51 | |
| 52 | /* ************************************* |
| 53 | * Explicit memory management |
| 54 | ***************************************/ |
| 55 | /** Decompression context */ |
| 56 | typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx; |
| 57 | ZSTDv05_DCtx* ZSTDv05_createDCtx(void); |
| 58 | size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */ |
| 59 | |
| 60 | /** ZSTDv05_decompressDCtx() : |
| 61 | * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */ |
| 62 | size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); |
| 63 | |
| 64 | |
| 65 | /*-*********************** |
| 66 | * Simple Dictionary API |
| 67 | *************************/ |
| 68 | /*! ZSTDv05_decompress_usingDict() : |
| 69 | * Decompression using a pre-defined Dictionary content (see dictBuilder). |
| 70 | * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted. |
| 71 | * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */ |
| 72 | size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx, |
| 73 | void* dst, size_t dstCapacity, |
| 74 | const void* src, size_t srcSize, |
| 75 | const void* dict,size_t dictSize); |
| 76 | |
| 77 | /*-************************ |
| 78 | * Advanced Streaming API |
| 79 | ***************************/ |
| 80 | typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy; |
| 81 | typedef struct { |
| 82 | U64 srcSize; |
| 83 | U32 windowLog; /* the only useful information to retrieve */ |
| 84 | U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy; |
| 85 | } ZSTDv05_parameters; |
| 86 | size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize); |
| 87 | |
| 88 | size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize); |
| 89 | void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx); |
| 90 | size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx); |
| 91 | size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); |
| 92 | |
| 93 | |
| 94 | /*-*********************** |
| 95 | * ZBUFF API |
| 96 | *************************/ |
| 97 | typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx; |
| 98 | ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void); |
| 99 | size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx); |
| 100 | |
| 101 | size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx); |
| 102 | size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize); |
| 103 | |
| 104 | size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx, |
| 105 | void* dst, size_t* dstCapacityPtr, |
| 106 | const void* src, size_t* srcSizePtr); |
| 107 | |
| 108 | /*-*************************************************************************** |
| 109 | * Streaming decompression |
| 110 | * |
| 111 | * A ZBUFFv05_DCtx object is required to track streaming operations. |
| 112 | * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources. |
| 113 | * Use ZBUFFv05_decompressInit() to start a new decompression operation, |
| 114 | * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary. |
| 115 | * Note that ZBUFFv05_DCtx objects can be reused multiple times. |
| 116 | * |
| 117 | * Use ZBUFFv05_decompressContinue() repetitively to consume your input. |
| 118 | * *srcSizePtr and *dstCapacityPtr can be any size. |
| 119 | * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. |
| 120 | * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. |
| 121 | * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst. |
| 122 | * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency) |
| 123 | * or 0 when a frame is completely decoded |
| 124 | * or an error code, which can be tested using ZBUFFv05_isError(). |
| 125 | * |
| 126 | * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize() |
| 127 | * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. |
| 128 | * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . |
| 129 | * *******************************************************************************/ |
| 130 | |
| 131 | |
| 132 | /* ************************************* |
| 133 | * Tool functions |
| 134 | ***************************************/ |
| 135 | unsigned ZBUFFv05_isError(size_t errorCode); |
| 136 | const char* ZBUFFv05_getErrorName(size_t errorCode); |
| 137 | |
| 138 | /** Functions below provide recommended buffer sizes for Compression or Decompression operations. |
| 139 | * These sizes are just hints, and tend to offer better latency */ |
| 140 | size_t ZBUFFv05_recommendedDInSize(void); |
| 141 | size_t ZBUFFv05_recommendedDOutSize(void); |
| 142 | |
| 143 | |
| 144 | |
| 145 | /*-************************************* |
| 146 | * Constants |
| 147 | ***************************************/ |
| 148 | #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */ |
| 149 | |
| 150 | |
| 151 | |
| 152 | |
| 153 | #if defined (__cplusplus) |
| 154 | } |
| 155 | #endif |
| 156 | |
| 157 | #endif /* ZSTDv0505_H */ |