/*
* Copyright (c) 2009-2013 Petri Lehtinen <petri@digip.org>
* Copyright (c) 2011-2012 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
*
* Jansson is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See LICENSE for details.
*/
#include <string.h>
#include "jansson.h"
#include "jansson_private.h"
#include "utf.h"
typedef struct {
int line;
int column;
size_t pos;
char token;
} token_t;
typedef struct {
const char *start;
const char *fmt;
token_t prev_token;
token_t token;
token_t next_token;
json_error_t *error;
size_t flags;
int line;
int column;
size_t pos;
} scanner_t;
#define token(scanner) ((scanner)->token.token)
static const char * const type_names[] = {
"object",
"array",
"string",
"integer",
"real",
"true",
"false",
"null"
};
#define type_name(x) type_names[json_typeof(x)]
static const char unpack_value_starters[] = "{[siIbfFOon";
static void scanner_init(scanner_t *s, json_error_t *error,
size_t flags, const char *fmt)
{
s->error = error;
s->flags = flags;
s->fmt = s->start = fmt;
memset(&s->prev_token, 0, sizeof(token_t));
memset(&s->token, 0, sizeof(token_t));
memset(&s->next_token, 0, sizeof(token_t));
s->line = 1;
s->column = 0;
s->pos = 0;
}
static void next_token(scanner_t *s)
{
const char *t;
s->prev_token = s->token;
if(s->next_token.line) {
s->token = s->next_token;
s->next_token.line = 0;
return;
}
t = s->fmt;
s->column++;
s->pos++;
/* skip space and ignored chars */
while(*t == ' ' || *t == '\t' || *t == '\n' || *t == ',' || *t == ':') {
if(*t == '\n') {
s->line++;
s->column = 1;
}
else
s->column++;
s->pos++;
t++;
}
s->token.token = *t;
s->token.line = s->line;
s->token.column = s->column;
s->token.pos = s->pos;
t++;
s->fmt = t;
}
static void prev_token(scanner_t *s)
{
s->next_token = s->token;
s->token = s->prev_token;
}
static void set_error(scanner_t *s, const char *source, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
jsonp_error_vset(s->error, s->token.line, s->token.column, s->token.pos,
fmt, ap);
jsonp_error_set_source(s->error, source);
va_end(ap);
}
static json_t *pack(scanner_t *s, va_list *ap);
/* ours will be set to 1 if jsonp_free() must be called for the result
afterwards */
static char *read_string(scanner_t *s, va_list *ap,
const char *purpose, int *ours)
{
char t;
strbuffer_t strbuff;
const char *str;
size_t length;
char *result;
next_token(s);
t = token(s);
prev_token(s);
if(t != '#' && t != '+') {
/* Optimize the simple case */
str = va_arg(*ap, const char *);
if(!str) {
set_error(s, "<args>", "NULL string argument");
return NULL;
}
if(!utf8_check_string(str, -1)) {
set_error(s, "<args>", "Invalid UTF-8 %s", purpose);
return NULL;
}
*ours = 0;
return (char *)str;
}
strbuffer_init(&strbuff);
while(1) {
str = va_arg(*ap, const char *);
if(!str) {
set_error(s, "<args>", "NULL string argument");
strbuffer_close(&strbuff);
return NULL;
}
next_token(s);
if(token(s) == '#') {
length = va_arg(*ap, int);
}
else {
prev_token(s);
length = strlen(str);
}
if(strbuffer_append_bytes(&strbuff, str, length) == -1) {
set_error(s, "<internal>", "Out of memory");
strbuffer_close(&strbuff);
return NULL;
}
next_token(s);
if(token(s) != '+') {
prev_token(s);
break;
}
}
result = strbuffer_steal_value(&strbuff);
if(!utf8_check_string(result, -1)) {
set_error(s, "<args>", "Invalid UTF-8 %s", purpose);
return NULL;
}
*ours = 1;
return result;
}
static json_t *pack_object(scanner_t *s, va_list *ap)
{
json_t *object = json_object();
next_token(s);
while(token(s) != '}') {
char *key;
int ours;
json_t *value;
if(!token(s)) {
set_error(s, "<format>", "Unexpected end of format string");
goto error;
}
if(token(s) != 's') {
set_error(s, "<format>", "Expected format 's', got '%c'", token(s));
goto error;
}
key = read_string(s, ap, "object key", &ours);
if(!key)
goto error;
next_token(s);
value = pack(s, ap);
if(!value)
goto error;
if(json_object_set_new_nocheck(object, key, value)) {
if(ours)
jsonp_free(key);
set_error(s, "<internal>", "Unable to add key \"%s\"", key);
goto error;
}
if(ours)
jsonp_free(key);
next_token(s);
}
return object;
error:
json_decref(object);
return NULL;
}
static json_t *pack_array(scanner_t *s, va_list *ap)
{
json_t *array = json_array();
next_token(s);
while(token(s) != ']') {
json_t *value;
if(!token(s)) {
set_error(s, "<format>", "Unexpected end of format string");
goto error;
}
value = pack(s, ap);
if(!value)
goto error;
if(json_array_append_new(array, value)) {
set_error(s, "<internal>", "Unable to append to array");
goto error;
}
next_token(s);
}
return array;
error:
json_decref(array);
return NULL;
}
static json_t *pack(scanner_t *s, va_list *ap)
{
switch(token(s)) {
case '{':
return pack_object(s, ap);
case '[':
return pack_array(s, ap);
case 's': { /* string */
char *str;
int ours;
json_t *result;
str = read_string(s, ap, "string", &ours);
if(!str)
return NULL;
result = json_string_nocheck(str);
if(ours)
jsonp_free(str);
return result;
}
case 'n': /* null */
return json_null();
case 'b': /* boolean */
return va_arg(*ap, int) ? json_true() : json_false();
case 'i': /* integer from int */
return json_integer(va_arg(*ap, int));
case 'I': /* integer from json_int_t */
return json_integer(va_arg(*ap, json_int_t));
case 'f': /* real */
return json_real(va_arg(*ap, double));
case 'O': /* a json_t object; increments refcount */
return json_incref(va_arg(*ap, json_t *));
case 'o': /* a json_t object; doesn't increment refcount */
return va_arg(*ap, json_t *);
default:
set_error(s, "<format>", "Unexpected format character '%c'",
token(s));
return NULL;
}
}
static int unpack(scanner_t *s, json_t *root, va_list *ap);
static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
{
int ret = -1;
int strict = 0;
/* Use a set (emulated by a hashtable) to check that all object
keys are accessed. Checking that the correct number of keys
were accessed is not enough, as the same key can be unpacked
multiple times.
*/
hashtable_t key_set;
if(hashtable_init(&key_set)) {
set_error(s, "<internal>", "Out of memory");
return -1;
}
if(root && !json_is_object(root)) {
set_error(s, "<validation>", "Expected object, got %s",
type_name(root));
goto out;
}
next_token(s);
while(token(s) != '}') {
const char *key;
json_t *value;
int opt = 0;
if(strict != 0) {
set_error(s, "<format>", "Expected '}' after '%c', got '%c'",
(strict == 1 ? '!' : '*'), token(s));
goto out;
}
if(!token(s)) {
set_error(s, "<format>", "Unexpected end of format string");
goto out;
}
if(token(s) == '!' || token(s) == '*') {
strict = (token(s) == '!' ? 1 : -1);
next_token(s);
continue;
}
if(token(s) != 's') {
set_error(s, "<format>", "Expected format 's', got '%c'", token(s));
goto out;
}
key = va_arg(*ap, const char *);
if(!key) {
set_error(s, "<args>", "NULL object key");
goto out;
}
next_token(s);
if(token(s) == '?') {
opt = 1;
next_token(s);
}
if(!root) {
/* skipping */
value = NULL;
}
else {
value = json_object_get(root, key);
if(!value && !opt) {
set_error(s, "<validation>", "Object item not found: %s", key);
goto out;
}
}
if(unpack(s, value, ap))
goto out;
hashtable_set(&key_set, key, 0, json_null());
next_token(s);
}
if(strict == 0 && (s->flags & JSON_STRICT))
strict = 1;
if(root && strict == 1 && key_set.size != json_object_size(root)) {
long diff = (long)json_object_size(root) - (long)key_set.size;
set_error(s, "<validation>", "%li object item(s) left unpacked", diff);
goto out;
}
ret = 0;
out:
hashtable_close(&key_set);
return ret;
}
static int unpack_array(scanner_t *s, json_t *root, va_list *ap)
{
size_t i = 0;
int strict = 0;
if(root && !json_is_array(root)) {
set_error(s, "<validation>", "Expected array, got %s", type_name(root));
return -1;
}
next_token(s);
while(token(s) != ']') {
json_t *value;
if(strict != 0) {
set_error(s, "<format>", "Expected ']' after '%c', got '%c'",
(strict == 1 ? '!' : '*'),
token(s));
return -1;
}
if(!token(s)) {
set_error(s, "<format>", "Unexpected end of format string");
return -1;
}
if(token(s) == '!' || token(s) == '*') {
strict = (token(s) == '!' ? 1 : -1);
next_token(s);
continue;
}
if(!strchr(unpack_value_starters, token(s))) {
set_error(s, "<format>", "Unexpected format character '%c'",
token(s));
return -1;
}
if(!root) {
/* skipping */
value = NULL;
}
else {
value = json_array_get(root, i);
if(!value) {
set_error(s, "<validation>", "Array index %lu out of range",
(unsigned long)i);
return -1;
}
}
if(unpack(s, value, ap))
return -1;
next_token(s);
i++;
}
if(strict == 0 && (s->flags & JSON_STRICT))
strict = 1;
if(root && strict == 1 && i != json_array_size(root)) {
long diff = (long)json_array_size(root) - (long)i;
set_error(s, "<validation>", "%li array item(s) left unpacked", diff);
return -1;
}
return 0;
}
static int unpack(scanner_t *s, json_t *root, va_list *ap)
{
switch(token(s))
{
case '{':
return unpack_object(s, root, ap);
case '[':
return unpack_array(s, root, ap);
case 's':
if(root && !json_is_string(root)) {
set_error(s, "<validation>", "Expected string, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
const char **target;
target = va_arg(*ap, const char **);
if(!target) {
set_error(s, "<args>", "NULL string argument");
return -1;
}
if(root)
*target = json_string_value(root);
}
return 0;
case 'i':
if(root && !json_is_integer(root)) {
set_error(s, "<validation>", "Expected integer, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
int *target = va_arg(*ap, int*);
if(root)
*target = (int)json_integer_value(root);
}
return 0;
case 'I':
if(root && !json_is_integer(root)) {
set_error(s, "<validation>", "Expected integer, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
json_int_t *target = va_arg(*ap, json_int_t*);
if(root)
*target = json_integer_value(root);
}
return 0;
case 'b':
if(root && !json_is_boolean(root)) {
set_error(s, "<validation>", "Expected true or false, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
int *target = va_arg(*ap, int*);
if(root)
*target = json_is_true(root);
}
return 0;
case 'f':
if(root && !json_is_real(root)) {
set_error(s, "<validation>", "Expected real, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
double *target = va_arg(*ap, double*);
if(root)
*target = json_real_value(root);
}
return 0;
case 'F':
if(root && !json_is_number(root)) {
set_error(s, "<validation>", "Expected real or integer, got %s",
type_name(root));
return -1;
}
if(!(s->flags & JSON_VALIDATE_ONLY)) {
double *target = va_arg(*ap, double*);
if(root)
*target = json_number_value(root);
}
return 0;
case 'O':
if(root && !(s->flags & JSON_VALIDATE_ONLY))
json_incref(root);
/* Fall through */
case 'o':
if(!(s->flags & JSON_VALIDATE_ONLY)) {
json_t **target = va_arg(*ap, json_t**);
if(root)
*target = root;
}
return 0;
case 'n':
/* Never assign, just validate */
if(root && !json_is_null(root)) {
set_error(s, "<validation>", "Expected null, got %s",
type_name(root));
return -1;
}
return 0;
default:
set_error(s, "<format>", "Unexpected format character '%c'",
token(s));
return -1;
}
}
json_t *json_vpack_ex(json_error_t *error, size_t flags,
const char *fmt, va_list ap)
{
scanner_t s;
va_list ap_copy;
json_t *value;
if(!fmt || !*fmt) {
jsonp_error_init(error, "<format>");
jsonp_error_set(error, -1, -1, 0, "NULL or empty format string");
return NULL;
}
jsonp_error_init(error, NULL);
scanner_init(&s, error, flags, fmt);
next_token(&s);
va_copy(ap_copy, ap);
value = pack(&s, &ap_copy);
va_end(ap_copy);
if(!value)
return NULL;
next_token(&s);
if(token(&s)) {
json_decref(value);
set_error(&s, "<format>", "Garbage after format string");
return NULL;
}
return value;
}
json_t *json_pack_ex(json_error_t *error, size_t flags, const char *fmt, ...)
{
json_t *value;
va_list ap;
va_start(ap, fmt);
value = json_vpack_ex(error, flags, fmt, ap);
va_end(ap);
return value;
}
json_t *json_pack(const char *fmt, ...)
{
json_t *value;
va_list ap;
va_start(ap, fmt);
value = json_vpack_ex(NULL, 0, fmt, ap);
va_end(ap);
return value;
}
int json_vunpack_ex(json_t *root, json_error_t *error, size_t flags,
const char *fmt, va_list ap)
{
scanner_t s;
va_list ap_copy;
if(!root) {
jsonp_error_init(error, "<root>");
jsonp_error_set(error, -1, -1, 0, "NULL root value");
return -1;
}
if(!fmt || !*fmt) {
jsonp_error_init(error, "<format>");
jsonp_error_set(error, -1, -1, 0, "NULL or empty format string");
return -1;
}
jsonp_error_init(error, NULL);
scanner_init(&s, error, flags, fmt);
next_token(&s);
va_copy(ap_copy, ap);
if(unpack(&s, root, &ap_copy)) {
va_end(ap_copy);
return -1;
}
va_end(ap_copy);
next_token(&s);
if(token(&s)) {
set_error(&s, "<format>", "Garbage after format string");
return -1;
}
return 0;
}
int json_unpack_ex(json_t *root, json_error_t *error, size_t flags, const char *fmt, ...)
{
int ret;
va_list ap;
va_start(ap, fmt);
ret = json_vunpack_ex(root, error, flags, fmt, ap);
va_end(ap);
return ret;
}
int json_unpack(json_t *root, const char *fmt, ...)
{
int ret;
va_list ap;
va_start(ap, fmt);
ret = json_vunpack_ex(root, NULL, 0, fmt, ap);
va_end(ap);
return ret;
}
