#include <stdlib.h> #include "jsmn.h" /** * Allocates a fresh unused token from the token pull. */ static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, jsmntok_t *tokens, size_t num_tokens) { jsmntok_t *tok; if (parser->toknext >= num_tokens) { return NULL; } tok = &tokens[parser->toknext++]; 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, jsmntype_t type, int start, int end) { token->type = type; token->start = start; token->end = end; token->size = 0; } /** * Fills next available token with JSON primitive. */ static jsmnerr_t jsmn_parse_primitive(jsmn_parser *parser, const char *js, size_t len, jsmntok_t *tokens, 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; } 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; } /** * Filsl next token with JSON string. */ static jsmnerr_t jsmn_parse_string(jsmn_parser *parser, const char *js, size_t len, jsmntok_t *tokens, 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. */ jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, size_t len, jsmntok_t *tokens, unsigned int num_tokens) { jsmnerr_t r; int i; jsmntok_t *token; int count = 0; 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) { tokens[parser->toksuper].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) { 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 && 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) { 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. */ void jsmn_init(jsmn_parser *parser) { parser->pos = 0; parser->toknext = 0; parser->toksuper = -1; }