| commit | author | age | ||
| d6b4a7 | 1 | /* |
| G | 2 | * coreJSON v3.2.0 |
| 3 | * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
| 4 | * | |
| 5 | * SPDX-License-Identifier: MIT | |
| 6 | * | |
| 7 | * Permission is hereby granted, free of charge, to any person obtaining a copy of | |
| 8 | * this software and associated documentation files (the "Software"), to deal in | |
| 9 | * the Software without restriction, including without limitation the rights to | |
| 10 | * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of | |
| 11 | * the Software, and to permit persons to whom the Software is furnished to do so, | |
| 12 | * subject to the following conditions: | |
| 13 | * | |
| 14 | * The above copyright notice and this permission notice shall be included in all | |
| 15 | * copies or substantial portions of the Software. | |
| 16 | * | |
| 17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| 18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS | |
| 19 | * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR | |
| 20 | * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER | |
| 21 | * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
| 22 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
| 23 | */ | |
| 24 | ||
| 25 | /** | |
| 26 | * @file core_json.h | |
| 27 | * @brief Include this header file to use coreJSON in your application. | |
| 28 | */ | |
| 29 | ||
| 30 | #ifndef CORE_JSON_H_ | |
| 31 | #define CORE_JSON_H_ | |
| 32 | ||
| 33 | #include <stdbool.h> | |
| 34 | #include <stddef.h> | |
| 35 | ||
| 36 | /* *INDENT-OFF* */ | |
| 37 | #ifdef __cplusplus | |
| 38 | extern "C" { | |
| 39 | #endif | |
| 40 | /* *INDENT-ON* */ | |
| 41 | ||
| 42 | /** | |
| 43 | * @ingroup json_enum_types | |
| 44 | * @brief Return codes from coreJSON library functions. | |
| 45 | */ | |
| 46 | typedef enum | |
| 47 | { | |
| 48 | JSONPartial = 0, /**< @brief JSON document is valid so far but incomplete. */ | |
| 49 | JSONSuccess, /**< @brief JSON document is valid and complete. */ | |
| 50 | JSONIllegalDocument, /**< @brief JSON document is invalid or malformed. */ | |
| 51 | JSONMaxDepthExceeded, /**< @brief JSON document has nesting that exceeds JSON_MAX_DEPTH. */ | |
| 52 | JSONNotFound, /**< @brief Query key could not be found in the JSON document. */ | |
| 53 | JSONNullParameter, /**< @brief Pointer parameter passed to a function is NULL. */ | |
| 54 | JSONBadParameter /**< @brief Query key is empty, or any subpart is empty, or max is 0. */ | |
| 55 | } JSONStatus_t; | |
| 56 | ||
| 57 | /** | |
| 58 | * @brief Parse a buffer to determine if it contains a valid JSON document. | |
| 59 | * | |
| 60 | * @param[in] buf The buffer to parse. | |
| 61 | * @param[in] max The size of the buffer. | |
| 62 | * | |
| 63 | * @note The maximum nesting depth may be specified by defining the macro | |
| 64 | * JSON_MAX_DEPTH. The default is 32 of sizeof(char). | |
| 65 | * | |
| 66 | * @note By default, a valid JSON document may contain a single element | |
| 67 | * (e.g., string, boolean, number). To require that a valid document | |
| 68 | * contain an object or array, define JSON_VALIDATE_COLLECTIONS_ONLY. | |
| 69 | * | |
| 70 | * @return #JSONSuccess if the buffer contents are valid JSON; | |
| 71 | * #JSONNullParameter if buf is NULL; | |
| 72 | * #JSONBadParameter if max is 0; | |
| 73 | * #JSONIllegalDocument if the buffer contents are NOT valid JSON; | |
| 74 | * #JSONMaxDepthExceeded if object and array nesting exceeds a threshold; | |
| 75 | * #JSONPartial if the buffer contents are potentially valid but incomplete. | |
| 76 | * | |
| 77 | * <b>Example</b> | |
| 78 | * @code{c} | |
| 79 | * // Variables used in this example. | |
| 80 | * JSONStatus_t result; | |
| 81 | * char buffer[] = "{\"foo\":\"abc\",\"bar\":{\"foo\":\"xyz\"}}"; | |
| 82 | * size_t bufferLength = sizeof( buffer ) - 1; | |
| 83 | * | |
| 84 | * result = JSON_Validate( buffer, bufferLength ); | |
| 85 | * | |
| 86 | * // JSON document is valid. | |
| 87 | * assert( result == JSONSuccess ); | |
| 88 | * @endcode | |
| 89 | */ | |
| 90 | /* @[declare_json_validate] */ | |
| 91 | JSONStatus_t JSON_Validate( const char * buf, | |
| 92 | size_t max ); | |
| 93 | /* @[declare_json_validate] */ | |
| 94 | ||
| 95 | /** | |
| 96 | * @brief Find a key or array index in a JSON document and output the | |
| 97 | * pointer @p outValue to its value. | |
| 98 | * | |
| 99 | * Any value may also be an object or an array to a maximum depth. A search | |
| 100 | * may descend through nested objects or arrays when the query contains matching | |
| 101 | * key strings or array indexes joined by a separator. | |
| 102 | * | |
| 103 | * For example, if the provided buffer contains <code>{"foo":"abc","bar":{"foo":"xyz"}}</code>, | |
| 104 | * then a search for 'foo' would output <code>abc</code>, 'bar' would output | |
| 105 | * <code>{"foo":"xyz"}</code>, and a search for 'bar.foo' would output | |
| 106 | * <code>xyz</code>. | |
| 107 | * | |
| 108 | * If the provided buffer contains <code>[123,456,{"foo":"abc","bar":[88,99]}]</code>, | |
| 109 | * then a search for '[1]' would output <code>456</code>, '[2].foo' would output | |
| 110 | * <code>abc</code>, and '[2].bar[0]' would output <code>88</code>. | |
| 111 | * | |
| 112 | * On success, the pointer @p outValue points to a location in buf. No null | |
| 113 | * termination is done for the value. For valid JSON it is safe to place | |
| 114 | * a null character at the end of the value, so long as the character | |
| 115 | * replaced is put back before running another search. | |
| 116 | * | |
| 117 | * @param[in] buf The buffer to search. | |
| 118 | * @param[in] max size of the buffer. | |
| 119 | * @param[in] query The object keys and array indexes to search for. | |
| 120 | * @param[in] queryLength Length of the key. | |
| 121 | * @param[out] outValue A pointer to receive the address of the value found. | |
| 122 | * @param[out] outValueLength A pointer to receive the length of the value found. | |
| 123 | * | |
| 124 | * @note The maximum nesting depth may be specified by defining the macro | |
| 125 | * JSON_MAX_DEPTH. The default is 32 of sizeof(char). | |
| 126 | * | |
| 127 | * @note JSON_Search() performs validation, but stops upon finding a matching | |
| 128 | * key and its value. To validate the entire JSON document, use JSON_Validate(). | |
| 129 | * | |
| 130 | * @return #JSONSuccess if the query is matched and the value output; | |
| 131 | * #JSONNullParameter if any pointer parameters are NULL; | |
| 132 | * #JSONBadParameter if the query is empty, or the portion after a separator is empty, | |
| 133 | * or max is 0, or an index is too large to convert to a signed 32-bit integer; | |
| 134 | * #JSONNotFound if the query has no match. | |
| 135 | * | |
| 136 | * <b>Example</b> | |
| 137 | * @code{c} | |
| 138 | * // Variables used in this example. | |
| 139 | * JSONStatus_t result; | |
| 140 | * char buffer[] = "{\"foo\":\"abc\",\"bar\":{\"foo\":\"xyz\"}}"; | |
| 141 | * size_t bufferLength = sizeof( buffer ) - 1; | |
| 142 | * char query[] = "bar.foo"; | |
| 143 | * size_t queryLength = sizeof( query ) - 1; | |
| 144 | * char * value; | |
| 145 | * size_t valueLength; | |
| 146 | * | |
| 147 | * // Calling JSON_Validate() is not necessary if the document is guaranteed to be valid. | |
| 148 | * result = JSON_Validate( buffer, bufferLength ); | |
| 149 | * | |
| 150 | * if( result == JSONSuccess ) | |
| 151 | * { | |
| 152 | * result = JSON_Search( buffer, bufferLength, query, queryLength, | |
| 153 | * &value, &valueLength ); | |
| 154 | * } | |
| 155 | * | |
| 156 | * if( result == JSONSuccess ) | |
| 157 | * { | |
| 158 | * // The pointer "value" will point to a location in the "buffer". | |
| 159 | * char save = value[ valueLength ]; | |
| 160 | * // After saving the character, set it to a null byte for printing. | |
| 161 | * value[ valueLength ] = '\0'; | |
| 162 | * // "Found: bar.foo -> xyz" will be printed. | |
| 163 | * printf( "Found: %s -> %s\n", query, value ); | |
| 164 | * // Restore the original character. | |
| 165 | * value[ valueLength ] = save; | |
| 166 | * } | |
| 167 | * @endcode | |
| 168 | * | |
| 169 | * @note The maximum index value is ~2 billion ( 2^31 - 9 ). | |
| 170 | */ | |
| 171 | /* @[declare_json_search] */ | |
| 172 | #define JSON_Search( buf, max, query, queryLength, outValue, outValueLength ) \ | |
| 173 | JSON_SearchT( buf, max, query, queryLength, outValue, outValueLength, NULL ) | |
| 174 | /* @[declare_json_search] */ | |
| 175 | ||
| 176 | /** | |
| 177 | * @brief The largest value usable as an array index in a query | |
| 178 | * for JSON_Search(), ~2 billion. | |
| 179 | */ | |
| 180 | #define MAX_INDEX_VALUE ( 0x7FFFFFF7 ) /* 2^31 - 9 */ | |
| 181 | ||
| 182 | /** | |
| 183 | * @ingroup json_enum_types | |
| 184 | * @brief Value types from the JSON standard. | |
| 185 | */ | |
| 186 | typedef enum | |
| 187 | { | |
| 188 | JSONInvalid = 0, /**< @brief Not a valid JSON type. */ | |
| 189 | JSONString, /**< @brief A quote delimited sequence of Unicode characters. */ | |
| 190 | JSONNumber, /**< @brief A rational number. */ | |
| 191 | JSONTrue, /**< @brief The literal value true. */ | |
| 192 | JSONFalse, /**< @brief The literal value false. */ | |
| 193 | JSONNull, /**< @brief The literal value null. */ | |
| 194 | JSONObject, /**< @brief A collection of zero or more key-value pairs. */ | |
| 195 | JSONArray /**< @brief A collection of zero or more values. */ | |
| 196 | } JSONTypes_t; | |
| 197 | ||
| 198 | /** | |
| 199 | * @brief Same as JSON_Search(), but also outputs a type for the value found | |
| 200 | * | |
| 201 | * See @ref JSON_Search for documentation of common behavior. | |
| 202 | * | |
| 203 | * @param[in] buf The buffer to search. | |
| 204 | * @param[in] max size of the buffer. | |
| 205 | * @param[in] query The object keys and array indexes to search for. | |
| 206 | * @param[in] queryLength Length of the key. | |
| 207 | * @param[out] outValue A pointer to receive the address of the value found. | |
| 208 | * @param[out] outValueLength A pointer to receive the length of the value found. | |
| 209 | * @param[out] outType An enum indicating the JSON-specific type of the value. | |
| 210 | */ | |
| 211 | /* @[declare_json_searcht] */ | |
| 212 | JSONStatus_t JSON_SearchT( char * buf, | |
| 213 | size_t max, | |
| 214 | const char * query, | |
| 215 | size_t queryLength, | |
| 216 | char ** outValue, | |
| 217 | size_t * outValueLength, | |
| 218 | JSONTypes_t * outType ); | |
| 219 | /* @[declare_json_searcht] */ | |
| 220 | ||
| 221 | /** | |
| 222 | * @brief Same as JSON_SearchT(), but with const qualified buf and outValue arguments. | |
| 223 | * | |
| 224 | * See @ref JSON_Search for documentation of common behavior. | |
| 225 | * | |
| 226 | * @param[in] buf The buffer to search. | |
| 227 | * @param[in] max size of the buffer. | |
| 228 | * @param[in] query The object keys and array indexes to search for. | |
| 229 | * @param[in] queryLength Length of the key. | |
| 230 | * @param[out] outValue A pointer to receive the address of the value found. | |
| 231 | * @param[out] outValueLength A pointer to receive the length of the value found. | |
| 232 | * @param[out] outType An enum indicating the JSON-specific type of the value. | |
| 233 | */ | |
| 234 | /* @[declare_json_searchconst] */ | |
| 235 | JSONStatus_t JSON_SearchConst( const char * buf, | |
| 236 | size_t max, | |
| 237 | const char * query, | |
| 238 | size_t queryLength, | |
| 239 | const char ** outValue, | |
| 240 | size_t * outValueLength, | |
| 241 | JSONTypes_t * outType ); | |
| 242 | /* @[declare_json_searchconst] */ | |
| 243 | ||
| 244 | /** | |
| 245 | * @ingroup json_struct_types | |
| 246 | * @brief Structure to represent a key-value pair. | |
| 247 | */ | |
| 248 | typedef struct | |
| 249 | { | |
| 250 | const char * key; /**< @brief Pointer to the code point sequence for key. */ | |
| 251 | size_t keyLength; /**< @brief Length of the code point sequence for key. */ | |
| 252 | const char * value; /**< @brief Pointer to the code point sequence for value. */ | |
| 253 | size_t valueLength; /**< @brief Length of the code point sequence for value. */ | |
| 254 | JSONTypes_t jsonType; /**< @brief JSON-specific type of the value. */ | |
| 255 | } JSONPair_t; | |
| 256 | ||
| 257 | /** | |
| 258 | * @brief Output the next key-value pair or value from a collection. | |
| 259 | * | |
| 260 | * This function may be used in a loop to output each key-value pair from an object, | |
| 261 | * or each value from an array. For the first invocation, the integers pointed to by | |
| 262 | * start and next should be initialized to 0. These will be updated by the function. | |
| 263 | * If another key-value pair or value is present, the output structure is populated | |
| 264 | * and #JSONSuccess is returned; otherwise the structure is unchanged and #JSONNotFound | |
| 265 | * is returned. | |
| 266 | * | |
| 267 | * @param[in] buf The buffer to search. | |
| 268 | * @param[in] max size of the buffer. | |
| 269 | * @param[in,out] start The index at which the collection begins. | |
| 270 | * @param[in,out] next The index at which to seek the next value. | |
| 271 | * @param[out] outPair A pointer to receive the next key-value pair. | |
| 272 | * | |
| 273 | * @note This function expects a valid JSON document; run JSON_Validate() first. | |
| 274 | * | |
| 275 | * @note For an object, the outPair structure will reference a key and its value. | |
| 276 | * For an array, only the value will be referenced (i.e., outPair.key will be NULL). | |
| 277 | * | |
| 278 | * @return #JSONSuccess if a value is output; | |
| 279 | * #JSONIllegalDocument if the buffer does not contain a collection; | |
| 280 | * #JSONNotFound if there are no further values in the collection. | |
| 281 | * | |
| 282 | * <b>Example</b> | |
| 283 | * @code{c} | |
| 284 | * // Variables used in this example. | |
| 285 | * static char * json_types[] = | |
| 286 | * { | |
| 287 | * "invalid", | |
| 288 | * "string", | |
| 289 | * "number", | |
| 290 | * "true", | |
| 291 | * "false", | |
| 292 | * "null", | |
| 293 | * "object", | |
| 294 | * "array" | |
| 295 | * }; | |
| 296 | * | |
| 297 | * void show( const char * json, | |
| 298 | * size_t length ) | |
| 299 | * { | |
| 300 | * size_t start = 0, next = 0; | |
| 301 | * JSONPair_t pair = { 0 }; | |
| 302 | * JSONStatus_t result; | |
| 303 | * | |
| 304 | * result = JSON_Validate( json, length ); | |
| 305 | * if( result == JSONSuccess ) | |
| 306 | * { | |
| 307 | * result = JSON_Iterate( json, length, &start, &next, &pair ); | |
| 308 | * } | |
| 309 | * | |
| 310 | * while( result == JSONSuccess ) | |
| 311 | * { | |
| 312 | * if( pair.key != NULL ) | |
| 313 | * { | |
| 314 | * printf( "key: %.*s\t", ( int ) pair.keyLength, pair.key ); | |
| 315 | * } | |
| 316 | * | |
| 317 | * printf( "value: (%s) %.*s\n", json_types[ pair.jsonType ], | |
| 318 | * ( int ) pair.valueLength, pair.value ); | |
| 319 | * | |
| 320 | * result = JSON_Iterate( json, length, &start, &next, &pair ); | |
| 321 | * } | |
| 322 | * } | |
| 323 | * @endcode | |
| 324 | */ | |
| 325 | /* @[declare_json_iterate] */ | |
| 326 | JSONStatus_t JSON_Iterate( const char * buf, | |
| 327 | size_t max, | |
| 328 | size_t * start, | |
| 329 | size_t * next, | |
| 330 | JSONPair_t * outPair ); | |
| 331 | /* @[declare_json_iterate] */ | |
| 332 | ||
| 333 | /* *INDENT-OFF* */ | |
| 334 | #ifdef __cplusplus | |
| 335 | } | |
| 336 | #endif | |
| 337 | /* *INDENT-ON* */ | |
| 338 | ||
| 339 | #endif /* ifndef CORE_JSON_H_ */ | |
