diff options
Diffstat (limited to 'strings/json_lib.c')
| -rw-r--r-- | strings/json_lib.c | 252 |
1 files changed, 251 insertions, 1 deletions
diff --git a/strings/json_lib.c b/strings/json_lib.c index 2b764e8827e..6c94ce2271e 100644 --- a/strings/json_lib.c +++ b/strings/json_lib.c @@ -772,7 +772,7 @@ static json_state_handler json_actions[NR_JSON_STATES][NR_C_CLASSES]= syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, not_json_chr, bad_chr}, {/*OBJ_CONT*/ - unexpected_eos, syntax_error, end_object, syntax_error, end_array, + unexpected_eos, syntax_error, end_object, syntax_error, syntax_error, syntax_error, next_key, syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, syntax_error, not_json_chr, bad_chr}, {/*ARRAY_CONT*/ @@ -1846,3 +1846,253 @@ int json_path_compare(const json_path_t *a, const json_path_t *b, b->steps+1, b->last_step, vt); } + +static enum json_types smart_read_value(json_engine_t *je, + const char **value, int *value_len) +{ + if (json_read_value(je)) + goto err_return; + + *value= (char *) je->value; + + if (json_value_scalar(je)) + *value_len= je->value_len; + else + { + if (json_skip_level(je)) + goto err_return; + + *value_len= (int) ((char *) je->s.c_str - *value); + } + + return je->value_type; + +err_return: + return JSV_BAD_JSON; +} + + +enum json_types json_type(const char *js, const char *js_end, + const char **value, int *value_len) +{ + json_engine_t je; + + json_scan_start(&je, &my_charset_utf8mb4_bin,(const uchar *) js, + (const uchar *) js_end); + + return smart_read_value(&je, value, value_len); +} + + +enum json_types json_get_array_item(const char *js, const char *js_end, + int n_item, + const char **value, int *value_len) +{ + json_engine_t je; + int c_item= 0; + + json_scan_start(&je, &my_charset_utf8mb4_bin,(const uchar *) js, + (const uchar *) js_end); + + if (json_read_value(&je) || + je.value_type != JSON_VALUE_ARRAY) + goto err_return; + + while (!json_scan_next(&je)) + { + switch (je.state) + { + case JST_VALUE: + if (c_item == n_item) + return smart_read_value(&je, value, value_len); + + if (json_skip_key(&je)) + goto err_return; + + c_item++; + break; + + case JST_ARRAY_END: + *value= (const char *) (je.s.c_str - je.sav_c_len); + *value_len= c_item; + return JSV_NOTHING; + } + } + +err_return: + return JSV_BAD_JSON; +} + + +/** Simple json lookup for a value by the key. + + Expects JSON object. + Only scans the 'first level' of the object, not + the nested structures. + + @param js [in] json object to search in + @param js_end [in] end of json string + @param key [in] key to search for + @param key_end [in] - " - + @param value_start [out] pointer into js (value or closing }) + @param value_len [out] length of the value found or number of keys + + @retval the type of the key value + @retval JSV_BAD_JSON - syntax error found reading JSON. + or not JSON object. + @retval JSV_NOTHING - no such key found. +*/ +enum json_types json_get_object_key(const char *js, const char *js_end, + const char *key, + const char **value, int *value_len) +{ + const char *key_end= key + strlen(key); + json_engine_t je; + json_string_t key_name; + int n_keys= 0; + + json_string_set_cs(&key_name, &my_charset_utf8mb4_bin); + + json_scan_start(&je, &my_charset_utf8mb4_bin,(const uchar *) js, + (const uchar *) js_end); + + if (json_read_value(&je) || + je.value_type != JSON_VALUE_OBJECT) + goto err_return; + + while (!json_scan_next(&je)) + { + switch (je.state) + { + case JST_KEY: + n_keys++; + json_string_set_str(&key_name, (const uchar *) key, + (const uchar *) key_end); + if (json_key_matches(&je, &key_name)) + return smart_read_value(&je, value, value_len); + + if (json_skip_key(&je)) + goto err_return; + + break; + + case JST_OBJ_END: + *value= (const char *) (je.s.c_str - je.sav_c_len); + *value_len= n_keys; + return JSV_NOTHING; + } + } + +err_return: + return JSV_BAD_JSON; +} + + +enum json_types json_get_object_nkey(const char *js,const char *js_end, int nkey, + const char **keyname, const char **keyname_end, + const char **value, int *value_len) +{ + return JSV_NOTHING; +} + + +/** Check if json is valid (well-formed) + + @retval 0 - success, json is well-formed + @retval 1 - error, json is invalid +*/ +int json_valid(const char *js, size_t js_len, CHARSET_INFO *cs) +{ + json_engine_t je; + json_scan_start(&je, cs, (const uchar *) js, (const uchar *) js + js_len); + while (json_scan_next(&je) == 0) /* no-op */ ; + return je.s.error == 0; +} + + +/* + Expects the JSON object as an js argument, and the key name. + Looks for this key in the object and returns + the location of all the text related to it. + The text includes the comma, separating this key. + + comma_pos - the hint where the comma is. It is important + if you plan to replace the key rather than just cut. + 1 - comma is on the left + 2 - comma is on the right. + 0 - no comma at all (the object has just this single key) + + if no such key found *key_start is set to NULL. +*/ +int json_locate_key(const char *js, const char *js_end, + const char *kname, + const char **key_start, const char **key_end, + int *comma_pos) +{ + const char *kname_end= kname + strlen(kname); + json_engine_t je; + json_string_t key_name; + int t_next, c_len, match_result; + + json_string_set_cs(&key_name, &my_charset_utf8mb4_bin); + + json_scan_start(&je, &my_charset_utf8mb4_bin,(const uchar *) js, + (const uchar *) js_end); + + if (json_read_value(&je) || + je.value_type != JSON_VALUE_OBJECT) + goto err_return; + + *key_start= (const char *) je.s.c_str; + *comma_pos= 0; + + while (!json_scan_next(&je)) + { + switch (je.state) + { + case JST_KEY: + json_string_set_str(&key_name, (const uchar *) kname, + (const uchar *) kname_end); + match_result= json_key_matches(&je, &key_name); + if (json_skip_key(&je)) + goto err_return; + get_first_nonspace(&je.s, &t_next, &c_len); + je.s.c_str-= c_len; + + if (match_result) + { + *key_end= (const char *) je.s.c_str; + + if (*comma_pos == 1) + return 0; + + DBUG_ASSERT(*comma_pos == 0); + + if (t_next == C_COMMA) + { + *key_end+= c_len; + *comma_pos= 2; + } + else if (t_next == C_RCURB) + *comma_pos= 0; + else + goto err_return; + return 0; + } + + *key_start= (const char *) je.s.c_str; + *comma_pos= 1; + break; + + case JST_OBJ_END: + *key_start= NULL; + return 0; + } + } + +err_return: + return 1; + +} + + |