/* * MIT License * * Copyright (c) 2010 Serge Zaitsev * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef JSMN_H #define JSMN_H #include #ifdef __cplusplus extern "C" { #endif #ifdef JSMN_STATIC #define JSMN_API static #else #define JSMN_API extern #endif /** * JSON type identifier. Basic types are: * o Object * o Array * o String * o Other primitive: number, boolean (true/false) or null */ typedef enum { JSMN_UNDEFINED = 0, JSMN_OBJECT = 1, JSMN_ARRAY = 2, JSMN_STRING = 3, JSMN_PRIMITIVE = 4 } jsmntype_t; enum jsmnerr { /* Not enough tokens were provided */ JSMN_ERROR_NOMEM = -1, /* Invalid character inside JSON string */ JSMN_ERROR_INVAL = -2, /* The string is not a full JSON packet, more bytes expected */ JSMN_ERROR_PART = -3 }; /** * JSON token description. * type type (object, array, string etc.) * start start position in JSON data string * end end position in JSON data string */ typedef struct jsmntok { jsmntype_t type; int start; int end; int size; #ifdef JSMN_PARENT_LINKS int parent; #endif } jsmntok_t; /** * JSON parser. Contains an array of token blocks available. Also stores * the string being parsed now and current position in that string. */ typedef struct jsmn_parser { unsigned int pos; /* offset in the JSON string */ unsigned int toknext; /* next token to allocate */ int toksuper; /* superior token node, e.g. parent object or array */ } jsmn_parser; /** * Create JSON parser over an array of tokens */ JSMN_API void jsmn_init(jsmn_parser *parser); /** * Run JSON parser. It parses a JSON data string into and array of tokens, each * describing * a single JSON object. */ JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const unsigned int num_tokens); #ifndef JSMN_HEADER /** * Allocates a fresh unused token from the token pool. */ static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, jsmntok_t *tokens, const size_t num_tokens) { jsmntok_t *tok; if (parser->toknext >= num_tokens) { return NULL; } tok = &tokens[parser->toknext++]; tok->type = JSMN_UNDEFINED; tok->start = tok->end = -1; tok->size = 0; #ifdef JSMN_PARENT_LINKS tok->parent = -1; #endif return tok; } /** * Fills token type and boundaries. */ static void jsmn_fill_token(jsmntok_t *token, const jsmntype_t type, const int start, const int end) { token->type = type; token->start = start; token->end = end; /*token->size = 0;*/ } /** * Fills next available token with JSON primitive. */ static int jsmn_parse_primitive(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const size_t num_tokens) { jsmntok_t *token; int start; start = parser->pos; for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) { switch (js[parser->pos]) { #ifndef JSMN_STRICT /* In strict mode primitive must be followed by "," or "}" or "]" */ case ':': #endif case '\t': case '\r': case '\n': case ' ': case ',': case ']': case '}': goto found; default: /* to quiet a warning from gcc*/ break; } if (js[parser->pos] < 32 || js[parser->pos] >= 127) { parser->pos = start; return JSMN_ERROR_INVAL; } } #ifdef JSMN_STRICT /* In strict mode primitive must be followed by a comma/object/array */ parser->pos = start; return JSMN_ERROR_PART; #endif found: if (tokens == NULL) { parser->pos--; return 0; } token = jsmn_alloc_token(parser, tokens, num_tokens); if (token == NULL) { parser->pos = start; return JSMN_ERROR_NOMEM; } jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos); #ifdef JSMN_PARENT_LINKS token->parent = parser->toksuper; #endif parser->pos--; return 0; } /** * Fills next token with JSON string. */ static int jsmn_parse_string(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const size_t num_tokens) { jsmntok_t *token; int start = parser->pos; parser->pos++; /* Skip starting quote */ for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) { char c = js[parser->pos]; /* Quote: end of string */ if (c == '\"') { if (tokens == NULL) { return 0; } token = jsmn_alloc_token(parser, tokens, num_tokens); if (token == NULL) { parser->pos = start; return JSMN_ERROR_NOMEM; } jsmn_fill_token(token, JSMN_STRING, start + 1, parser->pos); #ifdef JSMN_PARENT_LINKS token->parent = parser->toksuper; #endif return 0; } /* Backslash: Quoted symbol expected */ if (c == '\\' && parser->pos + 1 < len) { int i; parser->pos++; switch (js[parser->pos]) { /* Allowed escaped symbols */ case '\"': case '/': case '\\': case 'b': case 'f': case 'r': case 'n': case 't': break; /* Allows escaped symbol \uXXXX */ case 'u': parser->pos++; for (i = 0; i < 4 && parser->pos < len && js[parser->pos] != '\0'; i++) { /* If it isn't a hex character we have an error */ if (!((js[parser->pos] >= 48 && js[parser->pos] <= 57) || /* 0-9 */ (js[parser->pos] >= 65 && js[parser->pos] <= 70) || /* A-F */ (js[parser->pos] >= 97 && js[parser->pos] <= 102))) { /* a-f */ parser->pos = start; return JSMN_ERROR_INVAL; } parser->pos++; } parser->pos--; break; /* Unexpected symbol */ default: parser->pos = start; return JSMN_ERROR_INVAL; } } } parser->pos = start; return JSMN_ERROR_PART; } /** * Parse JSON string and fill tokens. */ JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const unsigned int num_tokens) { int r; int i; jsmntok_t *token; int count = parser->toknext; for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) { char c; jsmntype_t type; c = js[parser->pos]; switch (c) { case '{': case '[': count++; if (tokens == NULL) { break; } token = jsmn_alloc_token(parser, tokens, num_tokens); if (token == NULL) { return JSMN_ERROR_NOMEM; } if (parser->toksuper != -1) { jsmntok_t *t = &tokens[parser->toksuper]; #ifdef JSMN_STRICT /* In strict mode an object or array can't become a key */ if (t->type == JSMN_OBJECT) { return JSMN_ERROR_INVAL; } #endif t->size++; #ifdef JSMN_PARENT_LINKS token->parent = parser->toksuper; #endif } token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY); token->start = parser->pos; parser->toksuper = parser->toknext - 1; break; case '}': case ']': if (tokens == NULL) { break; } type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY); #ifdef JSMN_PARENT_LINKS if (parser->toknext < 1) { return JSMN_ERROR_INVAL; } token = &tokens[parser->toknext - 1]; for (;;) { if (token->start != -1 && token->end == -1) { if (token->type != type) { return JSMN_ERROR_INVAL; } token->end = parser->pos + 1; parser->toksuper = token->parent; break; } if (token->parent == -1) { if (token->type != type || parser->toksuper == -1) { return JSMN_ERROR_INVAL; } break; } token = &tokens[token->parent]; } #else for (i = parser->toknext - 1; i >= 0; i--) { token = &tokens[i]; if (token->start != -1 && token->end == -1) { if (token->type != type) { return JSMN_ERROR_INVAL; } parser->toksuper = -1; token->end = parser->pos + 1; break; } } /* Error if unmatched closing bracket */ if (i == -1) { return JSMN_ERROR_INVAL; } for (; i >= 0; i--) { token = &tokens[i]; if (token->start != -1 && token->end == -1) { parser->toksuper = i; break; } } #endif break; case '\"': r = jsmn_parse_string(parser, js, len, tokens, num_tokens); if (r < 0) { return r; } count++; if (parser->toksuper != -1 && tokens != NULL) { tokens[parser->toksuper].size++; } break; case '\t': case '\r': case '\n': case ' ': break; case ':': parser->toksuper = parser->toknext - 1; break; case ',': if (tokens != NULL && parser->toksuper != -1 && tokens[parser->toksuper].type != JSMN_ARRAY && tokens[parser->toksuper].type != JSMN_OBJECT) { #ifdef JSMN_PARENT_LINKS parser->toksuper = tokens[parser->toksuper].parent; #else for (i = parser->toknext - 1; i >= 0; i--) { if (tokens[i].type == JSMN_ARRAY || tokens[i].type == JSMN_OBJECT) { if (tokens[i].start != -1 && tokens[i].end == -1) { parser->toksuper = i; break; } } } #endif } break; #ifdef JSMN_STRICT /* In strict mode primitives are: numbers and booleans */ case '-': case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case 't': case 'f': case 'n': /* And they must not be keys of the object */ if (tokens != NULL && parser->toksuper != -1) { const jsmntok_t *t = &tokens[parser->toksuper]; if (t->type == JSMN_OBJECT || (t->type == JSMN_STRING && t->size != 0)) { return JSMN_ERROR_INVAL; } } #else /* In non-strict mode every unquoted value is a primitive */ default: #endif r = jsmn_parse_primitive(parser, js, len, tokens, num_tokens); if (r < 0) { return r; } count++; if (parser->toksuper != -1 && tokens != NULL) { tokens[parser->toksuper].size++; } break; #ifdef JSMN_STRICT /* Unexpected char in strict mode */ default: return JSMN_ERROR_INVAL; #endif } } if (tokens != NULL) { for (i = parser->toknext - 1; i >= 0; i--) { /* Unmatched opened object or array */ if (tokens[i].start != -1 && tokens[i].end == -1) { return JSMN_ERROR_PART; } } } return count; } /** * Creates a new parser based over a given buffer with an array of tokens * available. */ JSMN_API void jsmn_init(jsmn_parser *parser) { parser->pos = 0; parser->toknext = 0; parser->toksuper = -1; } #endif /* JSMN_HEADER */ #ifdef __cplusplus } #endif #endif /* JSMN_H */