diff options
Diffstat (limited to '')
-rw-r--r-- | libnetdata/json/jsmn.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/libnetdata/json/jsmn.c b/libnetdata/json/jsmn.c new file mode 100644 index 00000000..2f48bd65 --- /dev/null +++ b/libnetdata/json/jsmn.c @@ -0,0 +1,328 @@ +#include <stdlib.h> + +#include "jsmn.h" + +/** + * Alloc token + * + * Allocates a fresh unused token from the token pull. + * + * @param parser the controller + * @param tokens the tokens I am working + * @param num_tokens the number total of tokens. + * + * @return it returns the next token to work. + */ +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; +} + +/** + * Fill Token + * + * Fills token type and boundaries. + * + * @param token the structure to set the values + * @param type is the token type + * @param start is the first position of the value + * @param end is the end of the value + */ +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; +} + +/** + * Parse primitive + * + * Fills next available token with JSON primitive. + * + * @param parser is the control structure + * @param js is the json string + * @param type is the token type + */ +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; +} + +/** + * Parse string + * + * Fills next token with JSON string. + * + * @param parser is the control structure + * @param js is the json string + * @param len is the js length + * @param tokens is structure with the tokens mapped. + * @param num_tokens is the total number of tokens + * + * @return It returns 0 on success and another integer otherwise + */ +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++; + 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++; + int i = 0; + for(; i < 4 && 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; +} + +/** + * JSMN Parse + * + * Parse JSON string and fill tokens. + * + * @param parser the auxiliary vector used to parser + * @param js the string to parse + * @param len the string length + * @param tokens the place to map the tokens + * @param num_tokens the number of tokens present in the tokens structure. + * + * @return It returns the number of tokens present in the string on success or a negative number otherwise + */ +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 ':' : case ',': case ' ': + 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' : +#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) { + 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; +} + +/** + * JSMN Init + * + * Creates a new parser based over a given buffer with an array of tokens + * available. + * + * @param parser is the structure with values to reset + */ +void jsmn_init(jsmn_parser *parser) { + parser->pos = 0; + parser->toknext = 0; + parser->toksuper = -1; +}
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