1 /* Copyright 2013 Google Inc. All Rights Reserved. 2 3 Distributed under MIT license. 4 See file LICENSE for detail or copy at https://opensource.org/licenses/MIT 5 */ 6 7 /** 8 * @file 9 * API for Brotli decompression. 10 */ 11 12 #ifndef BROTLI_DEC_DECODE_H_ 13 #define BROTLI_DEC_DECODE_H_ 14 15 #include <brotli/port.h> 16 #include <brotli/types.h> 17 18 #if defined(__cplusplus) || defined(c_plusplus) 19 extern "C" { 20 #endif 21 22 /** 23 * Opaque structure that holds decoder state. 24 * 25 * Allocated and initialized with ::BrotliDecoderCreateInstance. 26 * Cleaned up and deallocated with ::BrotliDecoderDestroyInstance. 27 */ 28 typedef struct BrotliDecoderStateStruct BrotliDecoderState; 29 30 /** 31 * Result type for ::BrotliDecoderDecompress and 32 * ::BrotliDecoderDecompressStream functions. 33 */ 34 typedef enum { 35 /** Decoding error, e.g. corrupted input or memory allocation problem. */ 36 BROTLI_DECODER_RESULT_ERROR = 0, 37 /** Decoding successfully completed */ 38 BROTLI_DECODER_RESULT_SUCCESS = 1, 39 /** Partially done; should be called again with more input */ 40 BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT = 2, 41 /** Partially done; should be called again with more output */ 42 BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT = 3 43 } BrotliDecoderResult; 44 45 /** 46 * Template that evaluates items of ::BrotliDecoderErrorCode. 47 * 48 * Example: @code {.cpp} 49 * // Log Brotli error code. 50 * switch (brotliDecoderErrorCode) { 51 * #define CASE_(PREFIX, NAME, CODE) \ 52 * case BROTLI_DECODER ## PREFIX ## NAME: \ 53 * LOG(INFO) << "error code:" << #NAME; \ 54 * break; 55 * #define NEWLINE_ 56 * BROTLI_DECODER_ERROR_CODES_LIST(CASE_, NEWLINE_) 57 * #undef CASE_ 58 * #undef NEWLINE_ 59 * default: LOG(FATAL) << "unknown brotli error code"; 60 * } 61 * @endcode 62 */ 63 #define BROTLI_DECODER_ERROR_CODES_LIST(BROTLI_ERROR_CODE, SEPARATOR) \ 64 BROTLI_ERROR_CODE(_, NO_ERROR, 0) SEPARATOR \ 65 /* Same as BrotliDecoderResult values */ \ 66 BROTLI_ERROR_CODE(_, SUCCESS, 1) SEPARATOR \ 67 BROTLI_ERROR_CODE(_, NEEDS_MORE_INPUT, 2) SEPARATOR \ 68 BROTLI_ERROR_CODE(_, NEEDS_MORE_OUTPUT, 3) SEPARATOR \ 69 \ 70 /* Errors caused by invalid input */ \ 71 BROTLI_ERROR_CODE(_ERROR_FORMAT_, EXUBERANT_NIBBLE, -1) SEPARATOR \ 72 BROTLI_ERROR_CODE(_ERROR_FORMAT_, RESERVED, -2) SEPARATOR \ 73 BROTLI_ERROR_CODE(_ERROR_FORMAT_, EXUBERANT_META_NIBBLE, -3) SEPARATOR \ 74 BROTLI_ERROR_CODE(_ERROR_FORMAT_, SIMPLE_HUFFMAN_ALPHABET, -4) SEPARATOR \ 75 BROTLI_ERROR_CODE(_ERROR_FORMAT_, SIMPLE_HUFFMAN_SAME, -5) SEPARATOR \ 76 BROTLI_ERROR_CODE(_ERROR_FORMAT_, CL_SPACE, -6) SEPARATOR \ 77 BROTLI_ERROR_CODE(_ERROR_FORMAT_, HUFFMAN_SPACE, -7) SEPARATOR \ 78 BROTLI_ERROR_CODE(_ERROR_FORMAT_, CONTEXT_MAP_REPEAT, -8) SEPARATOR \ 79 BROTLI_ERROR_CODE(_ERROR_FORMAT_, BLOCK_LENGTH_1, -9) SEPARATOR \ 80 BROTLI_ERROR_CODE(_ERROR_FORMAT_, BLOCK_LENGTH_2, -10) SEPARATOR \ 81 BROTLI_ERROR_CODE(_ERROR_FORMAT_, TRANSFORM, -11) SEPARATOR \ 82 BROTLI_ERROR_CODE(_ERROR_FORMAT_, DICTIONARY, -12) SEPARATOR \ 83 BROTLI_ERROR_CODE(_ERROR_FORMAT_, WINDOW_BITS, -13) SEPARATOR \ 84 BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_1, -14) SEPARATOR \ 85 BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_2, -15) SEPARATOR \ 86 \ 87 /* -16..-19 codes are reserved */ \ 88 \ 89 BROTLI_ERROR_CODE(_ERROR_, INVALID_ARGUMENTS, -20) SEPARATOR \ 90 \ 91 /* Memory allocation problems */ \ 92 BROTLI_ERROR_CODE(_ERROR_ALLOC_, CONTEXT_MODES, -21) SEPARATOR \ 93 /* Literal, insert and distance trees together */ \ 94 BROTLI_ERROR_CODE(_ERROR_ALLOC_, TREE_GROUPS, -22) SEPARATOR \ 95 /* -23..-24 codes are reserved for distinct tree groups */ \ 96 BROTLI_ERROR_CODE(_ERROR_ALLOC_, CONTEXT_MAP, -25) SEPARATOR \ 97 BROTLI_ERROR_CODE(_ERROR_ALLOC_, RING_BUFFER_1, -26) SEPARATOR \ 98 BROTLI_ERROR_CODE(_ERROR_ALLOC_, RING_BUFFER_2, -27) SEPARATOR \ 99 /* -28..-29 codes are reserved for dynamic ring-buffer allocation */ \ 100 BROTLI_ERROR_CODE(_ERROR_ALLOC_, BLOCK_TYPE_TREES, -30) SEPARATOR \ 101 \ 102 /* "Impossible" states */ \ 103 BROTLI_ERROR_CODE(_ERROR_, UNREACHABLE, -31) 104 105 /** 106 * Error code for detailed logging / production debugging. 107 * 108 * See ::BrotliDecoderGetErrorCode and ::BROTLI_LAST_ERROR_CODE. 109 */ 110 typedef enum { 111 #define BROTLI_COMMA_ , 112 #define BROTLI_ERROR_CODE_ENUM_ITEM_(PREFIX, NAME, CODE) \ 113 BROTLI_DECODER ## PREFIX ## NAME = CODE 114 BROTLI_DECODER_ERROR_CODES_LIST(BROTLI_ERROR_CODE_ENUM_ITEM_, BROTLI_COMMA_) 115 } BrotliDecoderErrorCode; 116 #undef BROTLI_ERROR_CODE_ENUM_ITEM_ 117 #undef BROTLI_COMMA_ 118 119 /** 120 * The value of the last error code, negative integer. 121 * 122 * All other error code values are in the range from ::BROTLI_LAST_ERROR_CODE 123 * to @c -1. There are also 4 other possible non-error codes @c 0 .. @c 3 in 124 * ::BrotliDecoderErrorCode enumeration. 125 */ 126 #define BROTLI_LAST_ERROR_CODE BROTLI_DECODER_ERROR_UNREACHABLE 127 128 /** 129 * Creates an instance of ::BrotliDecoderState and initializes it. 130 * 131 * The instance can be used once for decoding and should then be destroyed with 132 * ::BrotliDecoderDestroyInstance, it cannot be reused for a new decoding 133 * session. 134 * 135 * @p alloc_func and @p free_func @b MUST be both zero or both non-zero. In the 136 * case they are both zero, default memory allocators are used. @p opaque is 137 * passed to @p alloc_func and @p free_func when they are called. 138 * 139 * @param alloc_func custom memory allocation function 140 * @param free_func custom memory fee function 141 * @param opaque custom memory manager handle 142 * @returns @c 0 if instance can not be allocated or initialized 143 * @returns pointer to initialized ::BrotliDecoderState otherwise 144 */ 145 BROTLI_DEC_API BrotliDecoderState* BrotliDecoderCreateInstance( 146 brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque); 147 148 /** 149 * Deinitializes and frees ::BrotliDecoderState instance. 150 * 151 * @param state decoder instance to be cleaned up and deallocated 152 */ 153 BROTLI_DEC_API void BrotliDecoderDestroyInstance(BrotliDecoderState* state); 154 155 /** 156 * Performs one-shot memory-to-memory decompression. 157 * 158 * Decompresses the data in @p encoded_buffer into @p decoded_buffer, and sets 159 * @p *decoded_size to the decompressed length. 160 * 161 * @param encoded_size size of @p encoded_buffer 162 * @param encoded_buffer compressed data buffer with at least @p encoded_size 163 * addressable bytes 164 * @param[in, out] decoded_size @b in: size of @p decoded_buffer; \n 165 * @b out: length of decompressed data written to 166 * @p decoded_buffer 167 * @param decoded_buffer decompressed data destination buffer 168 * @returns ::BROTLI_DECODER_RESULT_ERROR if input is corrupted, memory 169 * allocation failed, or @p decoded_buffer is not large enough; 170 * @returns ::BROTLI_DECODER_RESULT_SUCCESS otherwise 171 */ 172 BROTLI_DEC_API BrotliDecoderResult BrotliDecoderDecompress( 173 size_t encoded_size, 174 const uint8_t encoded_buffer[BROTLI_ARRAY_PARAM(encoded_size)], 175 size_t* decoded_size, 176 uint8_t decoded_buffer[BROTLI_ARRAY_PARAM(*decoded_size)]); 177 178 /** 179 * Decompresses the input stream to the output stream. 180 * 181 * The values @p *available_in and @p *available_out must specify the number of 182 * bytes addressable at @p *next_in and @p *next_out respectively. 183 * When @p *available_out is @c 0, @p next_out is allowed to be @c NULL. 184 * 185 * After each call, @p *available_in will be decremented by the amount of input 186 * bytes consumed, and the @p *next_in pointer will be incremented by that 187 * amount. Similarly, @p *available_out will be decremented by the amount of 188 * output bytes written, and the @p *next_out pointer will be incremented by 189 * that amount. 190 * 191 * @p total_out, if it is not a null-pointer, will be set to the number 192 * of bytes decompressed since the last @p state initialization. 193 * 194 * @note Input is never overconsumed, so @p next_in and @p available_in could be 195 * passed to the next consumer after decoding is complete. 196 * 197 * @param state decoder instance 198 * @param[in, out] available_in @b in: amount of available input; \n 199 * @b out: amount of unused input 200 * @param[in, out] next_in pointer to the next compressed byte 201 * @param[in, out] available_out @b in: length of output buffer; \n 202 * @b out: remaining size of output buffer 203 * @param[in, out] next_out output buffer cursor; 204 * can be @c NULL if @p available_out is @c 0 205 * @param[out] total_out number of bytes decompressed so far; can be @c NULL 206 * @returns ::BROTLI_DECODER_RESULT_ERROR if input is corrupted, memory 207 * allocation failed, arguments were invalid, etc.; 208 * use ::BrotliDecoderGetErrorCode to get detailed error code 209 * @returns ::BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT decoding is blocked until 210 * more output space is provided 211 * @returns ::BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT decoding is blocked until 212 * more input data is provided 213 * @returns ::BROTLI_DECODER_RESULT_SUCCESS decoding is finished, no more 214 * input might be consumed and no more output will be produced 215 */ 216 BROTLI_DEC_API BrotliDecoderResult BrotliDecoderDecompressStream( 217 BrotliDecoderState* state, size_t* available_in, const uint8_t** next_in, 218 size_t* available_out, uint8_t** next_out, size_t* total_out); 219 220 /** 221 * Prepends LZ77 dictionary. 222 * 223 * Fills the fresh ::BrotliDecoderState with additional data corpus for LZ77 224 * backward references. 225 * 226 * @note Not to be confused with the static dictionary (see RFC7932 section 8). 227 * @warning The dictionary must exist in memory until decoding is done and 228 * is owned by the caller. 229 * 230 * Workflow: 231 * -# Allocate and initialize state with ::BrotliDecoderCreateInstance 232 * -# Invoke ::BrotliDecoderSetCustomDictionary 233 * -# Use ::BrotliDecoderDecompressStream 234 * -# Clean up and free state with ::BrotliDecoderDestroyInstance 235 * 236 * @param state decoder instance 237 * @param size length of @p dict; should be less or equal to 2^24 (16MiB), 238 * otherwise the dictionary will be ignored 239 * @param dict "dictionary"; @b MUST be the same as used during compression 240 */ 241 BROTLI_DEC_API void BrotliDecoderSetCustomDictionary( 242 BrotliDecoderState* state, size_t size, 243 const uint8_t dict[BROTLI_ARRAY_PARAM(size)]); 244 245 /** 246 * Checks if decoder has more output. 247 * 248 * @param state decoder instance 249 * @returns ::BROTLI_TRUE, if decoder has some unconsumed output 250 * @returns ::BROTLI_FALSE otherwise 251 */ 252 BROTLI_DEC_API BROTLI_BOOL BrotliDecoderHasMoreOutput( 253 const BrotliDecoderState* state); 254 255 /** 256 * Acquires pointer to internal output buffer. 257 * 258 * This method is used to make language bindings easier and more efficient: 259 * -# push data to ::BrotliDecoderDecompressStream, 260 * until ::BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT is reported 261 * -# use ::BrotliDecoderTakeOutput to peek bytes and copy to language-specific 262 * entity 263 * 264 * Also this could be useful if there is an output stream that is able to 265 * consume all the provided data (e.g. when data is saved to file system). 266 * 267 * @attention After every call to ::BrotliDecoderTakeOutput @p *size bytes of 268 * output are considered consumed for all consecutive calls to the 269 * instance methods; returned pointer becomes invalidated as well. 270 * 271 * @note Decoder output is not guaranteed to be contiguous. This means that 272 * after the size-unrestricted call to ::BrotliDecoderTakeOutput, 273 * immediate next call to ::BrotliDecoderTakeOutput may return more data. 274 * 275 * @param state decoder instance 276 * @param[in, out] size @b in: number of bytes caller is ready to take, @c 0 if 277 * any amount could be handled; \n 278 * @b out: amount of data pointed by returned pointer and 279 * considered consumed; \n 280 * out value is never greater than in value, unless it is @c 0 281 * @returns pointer to output data 282 */ 283 BROTLI_DEC_API const uint8_t* BrotliDecoderTakeOutput( 284 BrotliDecoderState* state, size_t* size); 285 286 /** 287 * Checks if instance has already consumed input. 288 * 289 * Instance that returns ::BROTLI_FALSE is considered "fresh" and could be 290 * reused. 291 * 292 * @param state decoder instance 293 * @returns ::BROTLI_TRUE if decoder has already used some input bytes 294 * @returns ::BROTLI_FALSE otherwise 295 */ 296 BROTLI_DEC_API BROTLI_BOOL BrotliDecoderIsUsed(const BrotliDecoderState* state); 297 298 /** 299 * Checks if decoder instance reached the final state. 300 * 301 * @param state decoder instance 302 * @returns ::BROTLI_TRUE if decoder is in a state where it reached the end of 303 * the input and produced all of the output 304 * @returns ::BROTLI_FALSE otherwise 305 */ 306 BROTLI_BOOL BrotliDecoderIsFinished(const BrotliDecoderState* state); 307 308 /** 309 * Acquires a detailed error code. 310 * 311 * Should be used only after ::BrotliDecoderDecompressStream returns 312 * ::BROTLI_DECODER_RESULT_ERROR. 313 * 314 * See also ::BrotliDecoderErrorString 315 * 316 * @param state decoder instance 317 * @returns last saved error code 318 */ 319 BrotliDecoderErrorCode BrotliDecoderGetErrorCode( 320 const BrotliDecoderState* state); 321 322 /** 323 * Converts error code to a c-string. 324 */ 325 BROTLI_DEC_API const char* BrotliDecoderErrorString(BrotliDecoderErrorCode c); 326 327 /** 328 * Gets a decoder library version. 329 * 330 * Look at BROTLI_VERSION for more information. 331 */ 332 BROTLI_DEC_API uint32_t BrotliDecoderVersion(void); 333 334 #if defined(__cplusplus) || defined(c_plusplus) 335 } /* extern "C" */ 336 #endif 337 338 #endif /* BROTLI_DEC_DECODE_H_ */ 339
