src/libnetdata/json/json.c
#include "jsmn.h"
#include "../libnetdata.h"
#include "json.h"
#include "libnetdata/libnetdata.h"
#include "health/health.h"
#define JSON_TOKENS 1024
int json_tokens = JSON_TOKENS;
/**
* Json Tokenise
*
* Map the string given inside tokens.
*
* @param js is the string used to create the tokens
* @param len is the string length
* @param count the number of tokens present in the string
*
* @return it returns the json parsed in tokens
*/
#ifdef ENABLE_JSONC
json_object *json_tokenise(char *js) {
if(!js) {
netdata_log_error("JSON: json string is empty.");
return NULL;
}
json_object *token = json_tokener_parse(js);
if(!token) {
netdata_log_error("JSON: Invalid json string.");
return NULL;
}
return token;
}
#else
jsmntok_t *json_tokenise(char *js, size_t len, size_t *count)
{
int n = json_tokens;
if(!js || !len) {
netdata_log_error("JSON: json string is empty.");
return NULL;
}
jsmn_parser parser;
jsmn_init(&parser);
jsmntok_t *tokens = mallocz(sizeof(jsmntok_t) * n);
if(!tokens) return NULL;
int ret = jsmn_parse(&parser, js, len, tokens, n);
while (ret == JSMN_ERROR_NOMEM) {
n *= 2;
jsmntok_t *new = reallocz(tokens, sizeof(jsmntok_t) * n);
if(!new) {
freez(tokens);
return NULL;
}
tokens = new;
ret = jsmn_parse(&parser, js, len, tokens, n);
}
if (ret == JSMN_ERROR_INVAL) {
netdata_log_error("JSON: Invalid json string.");
freez(tokens);
return NULL;
}
else if (ret == JSMN_ERROR_PART) {
netdata_log_error("JSON: Truncated JSON string.");
freez(tokens);
return NULL;
}
if(count) *count = (size_t)ret;
if(json_tokens < n) json_tokens = n;
return tokens;
}
#endif
/**
* Callback Print
*
* Set callback print case necessary and wrinte an information inside a buffer to write in the log.
*
* @param e a pointer for a structure that has the complete information about json structure.
*
* @return It always return 0
*/
int json_callback_print(JSON_ENTRY *e)
{
BUFFER *wb=buffer_create(300, NULL);
buffer_sprintf(wb,"%s = ", e->name);
char txt[50];
switch(e->type) {
case JSON_OBJECT:
e->callback_function = json_callback_print;
buffer_strcat(wb,"OBJECT");
break;
case JSON_ARRAY:
e->callback_function = json_callback_print;
sprintf(txt,"ARRAY[%lu]", (long unsigned int) e->data.items);
buffer_strcat(wb, txt);
break;
case JSON_STRING:
buffer_strcat(wb, e->data.string);
break;
case JSON_NUMBER:
sprintf(txt, NETDATA_DOUBLE_FORMAT_AUTO, e->data.number);
buffer_strcat(wb,txt);
break;
case JSON_BOOLEAN:
buffer_strcat(wb, e->data.boolean?"TRUE":"FALSE");
break;
case JSON_NULL:
buffer_strcat(wb,"NULL");
break;
}
netdata_log_info("JSON: %s", buffer_tostring(wb));
buffer_free(wb);
return 0;
}
/**
* JSONC Set String
*
* Set the string value of the structure JSON_ENTRY.
*
* @param e the output structure
*/
static inline void json_jsonc_set_string(JSON_ENTRY *e,char *key,const char *value) {
size_t len = strlen(key);
if(len > JSON_NAME_LEN)
len = JSON_NAME_LEN;
e->type = JSON_STRING;
memcpy(e->name,key,len);
e->name[len] = 0x00;
e->data.string = (char *) value;
}
#ifdef ENABLE_JSONC
/**
* JSONC set Boolean
*
* Set the boolean value of the structure JSON_ENTRY
*
* @param e the output structure
* @param value the input value
*/
static inline void json_jsonc_set_boolean(JSON_ENTRY *e,int value) {
e->type = JSON_BOOLEAN;
e->data.boolean = value;
}
static inline void json_jsonc_set_integer(JSON_ENTRY *e, char *key, int64_t value) {
size_t len = strlen(key);
if(len > JSON_NAME_LEN)
len = JSON_NAME_LEN;
e->type = JSON_NUMBER;
memcpy(e->name, key, len);
e->name[len] = 0;
e->data.number = (NETDATA_DOUBLE)value;
}
/**
* Parse Array
*
* Parse the array object.
*
* @param ptr the pointer for the object that we will parse.
* @param callback_data additional data to be used together the callback function
* @param callback_function function used to create a silencer.
*/
static inline void json_jsonc_parse_array(json_object *ptr, void *callback_data,int (*callback_function)(struct json_entry *)) {
int end = json_object_array_length(ptr);
JSON_ENTRY e;
if(end) {
int i;
i = 0;
enum json_type type;
do {
json_object *jvalue = json_object_array_get_idx(ptr, i);
if(jvalue) {
e.callback_data = callback_data;
e.type = JSON_OBJECT;
callback_function(&e);
json_object_object_foreach(jvalue, key, val) {
type = json_object_get_type(val);
if (type == json_type_array) {
e.type = JSON_ARRAY;
json_jsonc_parse_array(val, callback_data, callback_function);
} else if (type == json_type_object) {
json_walk(val,callback_data,callback_function);
} else if (type == json_type_string) {
json_jsonc_set_string(&e,key,json_object_get_string(val));
callback_function(&e);
} else if (type == json_type_boolean) {
json_jsonc_set_boolean(&e,json_object_get_boolean(val));
callback_function(&e);
}
}
}
} while (++i < end);
}
}
#else
/**
* Walk string
*
* Set JSON_ENTRY to string and map the values from jsmntok_t.
*
* @param js the original string
* @param t the tokens
* @param start the first position
* @param e the output structure.
*
* @return It always return 1
*/
size_t json_walk_string(char *js, jsmntok_t *t, size_t start, JSON_ENTRY *e)
{
char old = js[t[start].end];
js[t[start].end] = '\0';
e->original_string = &js[t[start].start];
e->type = JSON_STRING;
e->data.string = e->original_string;
if(e->callback_function) e->callback_function(e);
js[t[start].end] = old;
return 1;
}
/**
* Walk Primitive
*
* Define the data type of the string
*
* @param js the original string
* @param t the tokens
* @param start the first position
* @param e the output structure.
*
* @return It always return 1
*/
size_t json_walk_primitive(char *js, jsmntok_t *t, size_t start, JSON_ENTRY *e)
{
char old = js[t[start].end];
js[t[start].end] = '\0';
e->original_string = &js[t[start].start];
switch(e->original_string[0]) {
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7':
case '8': case '9': case '-': case '.':
e->type = JSON_NUMBER;
e->data.number = strtold(e->original_string, NULL);
break;
case 't': case 'T':
e->type = JSON_BOOLEAN;
e->data.boolean = 1;
break;
case 'f': case 'F':
e->type = JSON_BOOLEAN;
e->data.boolean = 0;
break;
case 'n': case 'N':
default:
e->type = JSON_NULL;
break;
}
if(e->callback_function) e->callback_function(e);
js[t[start].end] = old;
return 1;
}
/**
* Array
*
* Measure the array length
*
* @param js the original string
* @param t the tokens
* @param nest the length of structure t
* @param start the first position
* @param e the structure with values and callback to be used inside the function.
*
* @return It returns the array length
*/
size_t json_walk_array(char *js, jsmntok_t *t, size_t nest, size_t start, JSON_ENTRY *e)
{
JSON_ENTRY ne;
char old = js[t[start].end];
js[t[start].end] = '\0';
ne.original_string = &js[t[start].start];
memcpy(&ne, e, sizeof(JSON_ENTRY));
ne.type = JSON_ARRAY;
ne.data.items = t[start].size;
ne.callback_function = e->callback_function;
ne.name[0]='\0';
ne.fullname[0]='\0';
if(e->callback_function) e->callback_function(&ne);
js[t[start].end] = old;
size_t i, init = start, size = t[start].size;
start++;
for(i = 0; i < size ; i++) {
ne.pos = i;
if (strlen(e->name) > JSON_NAME_LEN - 24 || strlen(e->fullname) > JSON_FULLNAME_LEN -24) {
netdata_log_info("JSON: JSON walk_array ignoring element with name:%s fullname:%s",e->name, e->fullname);
continue;
}
snprintfz(ne.name, JSON_NAME_LEN, "%s[%lu]", e->name, i);
snprintfz(ne.fullname, JSON_FULLNAME_LEN, "%s[%lu]", e->fullname, i);
switch(t[start].type) {
case JSMN_PRIMITIVE:
start += json_walk_primitive(js, t, start, &ne);
break;
case JSMN_OBJECT:
start += json_walk_object(js, t, nest + 1, start, &ne);
break;
case JSMN_ARRAY:
start += json_walk_array(js, t, nest + 1, start, &ne);
break;
case JSMN_STRING:
start += json_walk_string(js, t, start, &ne);
break;
}
}
return start - init;
}
/**
* Object
*
* Measure the Object length
*
* @param js the original string
* @param t the tokens
* @param nest the length of structure t
* @param start the first position
* @param e the output structure.
*
* @return It returns the Object length
*/
size_t json_walk_object(char *js, jsmntok_t *t, size_t nest, size_t start, JSON_ENTRY *e)
{
JSON_ENTRY ne = {
.name = "",
.fullname = "",
.callback_data = NULL,
.callback_function = NULL
};
char old = js[t[start].end];
js[t[start].end] = '\0';
ne.original_string = &js[t[start].start];
memcpy(&ne, e, sizeof(JSON_ENTRY));
ne.type = JSON_OBJECT;
ne.callback_function = e->callback_function;
if(e->callback_function) e->callback_function(&ne);
js[t[start].end] = old;
int key = 1;
size_t i, init = start, size = t[start].size;
start++;
for(i = 0; i < size ; i++) {
switch(t[start].type) {
case JSMN_PRIMITIVE:
start += json_walk_primitive(js, t, start, &ne);
key = 1;
break;
case JSMN_OBJECT:
start += json_walk_object(js, t, nest + 1, start, &ne);
key = 1;
break;
case JSMN_ARRAY:
start += json_walk_array(js, t, nest + 1, start, &ne);
key = 1;
break;
case JSMN_STRING:
default:
if(key) {
int len = t[start].end - t[start].start;
if (unlikely(len>JSON_NAME_LEN)) len=JSON_NAME_LEN;
strncpy(ne.name, &js[t[start].start], len);
ne.name[len] = '\0';
len=strlen(e->fullname) + strlen(e->fullname[0]?".":"") + strlen(ne.name);
char *c = mallocz((len+1)*sizeof(char));
sprintf(c,"%s%s%s", e->fullname, e->fullname[0]?".":"", ne.name);
if (unlikely(len>JSON_FULLNAME_LEN)) len=JSON_FULLNAME_LEN;
strncpy(ne.fullname, c, len);
freez(c);
start++;
key = 0;
}
else {
start += json_walk_string(js, t, start, &ne);
key = 1;
}
break;
}
}
return start - init;
}
#endif
/**
* Tree
*
* Call the correct walk function according its type.
*
* @param t the json object to work
* @param callback_data additional data to be used together the callback function
* @param callback_function function used to create a silencer.
*
* @return It always return 1
*/
#ifdef ENABLE_JSONC
size_t json_walk(json_object *t, void *callback_data, int (*callback_function)(struct json_entry *)) {
JSON_ENTRY e;
e.callback_data = callback_data;
enum json_type type;
json_object_object_foreach(t, key, val) {
type = json_object_get_type(val);
if (type == json_type_array) {
e.type = JSON_ARRAY;
json_jsonc_parse_array(val,NULL,health_silencers_json_read_callback);
} else if (type == json_type_object) {
e.type = JSON_OBJECT;
} else if (type == json_type_string) {
json_jsonc_set_string(&e,key,json_object_get_string(val));
callback_function(&e);
} else if (type == json_type_boolean) {
json_jsonc_set_boolean(&e,json_object_get_boolean(val));
callback_function(&e);
} else if (type == json_type_int) {
json_jsonc_set_integer(&e,key,json_object_get_int64(val));
callback_function(&e);
}
}
return 1;
}
#else
/**
* Tree
*
* Call the correct walk function according its type.
*
* @param js the original string
* @param t the tokens
* @param callback_data additional data to be used together the callback function
* @param callback_function function used to create a silencer.
*
* @return It always return 1
*/
size_t json_walk_tree(char *js, jsmntok_t *t, void *callback_data, int (*callback_function)(struct json_entry *))
{
JSON_ENTRY e = {
.name = "",
.fullname = "",
.callback_data = callback_data,
.callback_function = callback_function
};
switch (t[0].type) {
case JSMN_OBJECT:
e.type = JSON_OBJECT;
json_walk_object(js, t, 0, 0, &e);
break;
case JSMN_ARRAY:
e.type = JSON_ARRAY;
json_walk_array(js, t, 0, 0, &e);
break;
case JSMN_PRIMITIVE:
case JSMN_STRING:
break;
}
return 1;
}
#endif
/**
* JSON Parse
*
* Parse the json message with the callback function
*
* @param js the string that the callback function will parse
* @param callback_data additional data to be used together the callback function
* @param callback_function function used to create a silencer.
*
* @return JSON_OK case everything happened as expected, JSON_CANNOT_PARSE case there were errors in the
* parsing process and JSON_CANNOT_DOWNLOAD case the string given(js) is NULL.
*/
int json_parse(char *js, void *callback_data, int (*callback_function)(JSON_ENTRY *))
{
if(js) {
#ifdef ENABLE_JSONC
json_object *tokens = json_tokenise(js);
#else
size_t count;
jsmntok_t *tokens = json_tokenise(js, strlen(js), &count);
#endif
if(tokens) {
#ifdef ENABLE_JSONC
json_walk(tokens, callback_data, callback_function);
json_object_put(tokens);
#else
json_walk_tree(js, tokens, callback_data, callback_function);
freez(tokens);
#endif
return JSON_OK;
}
return JSON_CANNOT_PARSE;
}
return JSON_CANNOT_DOWNLOAD;
}
/*
int json_test(char *str)
{
return json_parse(str, NULL, json_callback_print);
}
*/