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/*
* $Id: json_tokener.c,v 1.20 2006/07/25 03:24:50 mclark Exp $
*
* Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
* Michael Clark <michael@metaparadigm.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See COPYING for details.
*
*
* Copyright (c) 2008-2009 Yahoo! Inc. All rights reserved.
* The copyrights to the contents of this file are licensed under the MIT License
* (http://www.opensource.org/licenses/mit-license.php)
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <string.h>
#include <limits.h>
#include "bits.h"
#include "debug.h"
#include "printbuf.h"
#include "arraylist.h"
#include "json_inttypes.h"
#include "json_object.h"
#include "json_tokener.h"
#include "json_util.h"
#if !HAVE_STRNCASECMP && defined(_MSC_VER)
/* MSC has the version as _strnicmp */
# define strncasecmp _strnicmp
#elif !HAVE_STRNCASECMP
# error You do not have strncasecmp on your system.
#endif /* HAVE_STRNCASECMP */
static const char* json_null_str = "null";
static const char* json_true_str = "true";
static const char* json_false_str = "false";
const char* json_tokener_errors[] = {
"success",
"continue",
"nesting to deep",
"unexpected end of data",
"unexpected character",
"null expected",
"boolean expected",
"number expected",
"array value separator ',' expected",
"quoted object property name expected",
"object property name separator ':' expected",
"object value separator ',' expected",
"invalid string sequence",
"expected comment",
};
/* Stuff for decoding unicode sequences */
#define IS_HIGH_SURROGATE(uc) (((uc) & 0xFC00) == 0xD800)
#define IS_LOW_SURROGATE(uc) (((uc) & 0xFC00) == 0xDC00)
#define DECODE_SURROGATE_PAIR(hi,lo) ((((hi) & 0x3FF) << 10) + ((lo) & 0x3FF) + 0x10000)
static unsigned char utf8_replacement_char[3] = { 0xEF, 0xBF, 0xBD };
struct json_tokener* json_tokener_new(void)
{
struct json_tokener *tok;
tok = (struct json_tokener*)calloc(1, sizeof(struct json_tokener));
if (!tok) return NULL;
tok->pb = printbuf_new();
json_tokener_reset(tok);
return tok;
}
void json_tokener_free(struct json_tokener *tok)
{
json_tokener_reset(tok);
if(tok) printbuf_free(tok->pb);
free(tok);
}
static void json_tokener_reset_level(struct json_tokener *tok, int depth)
{
tok->stack[depth].state = json_tokener_state_eatws;
tok->stack[depth].saved_state = json_tokener_state_start;
json_object_put(tok->stack[depth].current);
tok->stack[depth].current = NULL;
free(tok->stack[depth].obj_field_name);
tok->stack[depth].obj_field_name = NULL;
}
void json_tokener_reset(struct json_tokener *tok)
{
int i;
if (!tok)
return;
for(i = tok->depth; i >= 0; i--)
json_tokener_reset_level(tok, i);
tok->depth = 0;
tok->err = json_tokener_success;
}
struct json_object* json_tokener_parse(const char *str)
{
struct json_tokener* tok;
struct json_object* obj;
tok = json_tokener_new();
obj = json_tokener_parse_ex(tok, str, -1);
if(tok->err != json_tokener_success)
obj = NULL;
json_tokener_free(tok);
return obj;
}
struct json_object* json_tokener_parse_verbose(const char *str, enum json_tokener_error *error)
{
struct json_tokener* tok;
struct json_object* obj;
tok = json_tokener_new();
obj = json_tokener_parse_ex(tok, str, -1);
*error = tok->err;
if(tok->err != json_tokener_success) {
obj = NULL;
}
json_tokener_free(tok);
return obj;
}
#if !HAVE_STRNDUP
/* CAW: compliant version of strndup() */
char* strndup(const char* str, size_t n)
{
if(str) {
size_t len = strlen(str);
size_t nn = json_min(len,n);
char* s = (char*)malloc(sizeof(char) * (nn + 1));
if(s) {
memcpy(s, str, nn);
s[nn] = '\0';
}
return s;
}
return NULL;
}
#endif
#define state tok->stack[tok->depth].state
#define saved_state tok->stack[tok->depth].saved_state
#define current tok->stack[tok->depth].current
#define obj_field_name tok->stack[tok->depth].obj_field_name
/* Optimization:
* json_tokener_parse_ex() consumed a lot of CPU in its main loop,
* iterating character-by character. A large performance boost is
* achieved by using tighter loops to locally handle units such as
* comments and strings. Loops that handle an entire token within
* their scope also gather entire strings and pass them to
* printbuf_memappend() in a single call, rather than calling
* printbuf_memappend() one char at a time.
*
* POP_CHAR() and ADVANCE_CHAR() macros are used for code that is
* common to both the main loop and the tighter loops.
*/
/* POP_CHAR(dest, tok) macro:
* Not really a pop()...peeks at the current char and stores it in dest.
* Returns 1 on success, sets tok->err and returns 0 if no more chars.
* Implicit inputs: str, len vars
*/
#define POP_CHAR(dest, tok) \
(((tok)->char_offset == len) ? \
(((tok)->depth == 0 && state == json_tokener_state_eatws && saved_state == json_tokener_state_finish) ? \
(((tok)->err = json_tokener_success), 0) \
: \
(((tok)->err = json_tokener_continue), 0) \
) : \
(((dest) = *str), 1) \
)
/* ADVANCE_CHAR() macro:
* Incrementes str & tok->char_offset.
* For convenience of existing conditionals, returns the old value of c (0 on eof)
* Implicit inputs: c var
*/
#define ADVANCE_CHAR(str, tok) \
( ++(str), ((tok)->char_offset)++, c)
/* End optimization macro defs */
struct json_object* json_tokener_parse_ex(struct json_tokener *tok,
const char *str, int len)
{
struct json_object *obj = NULL;
char c = '\1';
tok->char_offset = 0;
tok->err = json_tokener_success;
while (POP_CHAR(c, tok)) {
redo_char:
switch(state) {
case json_tokener_state_eatws:
/* Advance until we change state */
while (isspace((int)c)) {
if ((!ADVANCE_CHAR(str, tok)) || (!POP_CHAR(c, tok)))
goto out;
}
if(c == '/') {
printbuf_reset(tok->pb);
printbuf_memappend_fast(tok->pb, &c, 1);
state = json_tokener_state_comment_start;
} else {
state = saved_state;
goto redo_char;
}
break;
case json_tokener_state_start:
switch(c) {
case '{':
state = json_tokener_state_eatws;
saved_state = json_tokener_state_object_field_start;
current = json_object_new_object();
break;
case '[':
state = json_tokener_state_eatws;
saved_state = json_tokener_state_array;
current = json_object_new_array();
break;
case 'N':
case 'n':
state = json_tokener_state_null;
printbuf_reset(tok->pb);
tok->st_pos = 0;
goto redo_char;
case '"':
case '\'':
state = json_tokener_state_string;
printbuf_reset(tok->pb);
tok->quote_char = c;
break;
case 'T':
case 't':
case 'F':
case 'f':
state = json_tokener_state_boolean;
printbuf_reset(tok->pb);
tok->st_pos = 0;
goto redo_char;
#if defined(__GNUC__)
case '0' ... '9':
#else
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
#endif
case '-':
state = json_tokener_state_number;
printbuf_reset(tok->pb);
tok->is_double = 0;
goto redo_char;
default:
tok->err = json_tokener_error_parse_unexpected;
goto out;
}
break;
case json_tokener_state_finish:
if(tok->depth == 0) goto out;
obj = json_object_get(current);
json_tokener_reset_level(tok, tok->depth);
tok->depth--;
goto redo_char;
case json_tokener_state_null:
printbuf_memappend_fast(tok->pb, &c, 1);
if(strncasecmp(json_null_str, tok->pb->buf,
json_min(tok->st_pos+1, strlen(json_null_str))) == 0) {
if(tok->st_pos == strlen(json_null_str)) {
current = NULL;
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
goto redo_char;
}
} else {
tok->err = json_tokener_error_parse_null;
goto out;
}
tok->st_pos++;
break;
case json_tokener_state_comment_start:
if(c == '*') {
state = json_tokener_state_comment;
} else if(c == '/') {
state = json_tokener_state_comment_eol;
} else {
tok->err = json_tokener_error_parse_comment;
goto out;
}
printbuf_memappend_fast(tok->pb, &c, 1);
break;
case json_tokener_state_comment:
{
/* Advance until we change state */
const char *case_start = str;
while(c != '*') {
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
goto out;
}
}
printbuf_memappend_fast(tok->pb, case_start, 1+str-case_start);
state = json_tokener_state_comment_end;
}
break;
case json_tokener_state_comment_eol:
{
/* Advance until we change state */
const char *case_start = str;
while(c != '\n') {
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
goto out;
}
}
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
MC_DEBUG("json_tokener_comment: %s\n", tok->pb->buf);
state = json_tokener_state_eatws;
}
break;
case json_tokener_state_comment_end:
printbuf_memappend_fast(tok->pb, &c, 1);
if(c == '/') {
MC_DEBUG("json_tokener_comment: %s\n", tok->pb->buf);
state = json_tokener_state_eatws;
} else {
state = json_tokener_state_comment;
}
break;
case json_tokener_state_string:
{
/* Advance until we change state */
const char *case_start = str;
while(1) {
if(c == tok->quote_char) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
current = json_object_new_string(tok->pb->buf);
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
break;
} else if(c == '\\') {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
saved_state = json_tokener_state_string;
state = json_tokener_state_string_escape;
break;
}
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
goto out;
}
}
}
break;
case json_tokener_state_string_escape:
switch(c) {
case '"':
case '\\':
case '/':
printbuf_memappend_fast(tok->pb, &c, 1);
state = saved_state;
break;
case 'b':
case 'n':
case 'r':
case 't':
if(c == 'b') printbuf_memappend_fast(tok->pb, "\b", 1);
else if(c == 'n') printbuf_memappend_fast(tok->pb, "\n", 1);
else if(c == 'r') printbuf_memappend_fast(tok->pb, "\r", 1);
else if(c == 't') printbuf_memappend_fast(tok->pb, "\t", 1);
state = saved_state;
break;
case 'u':
tok->ucs_char = 0;
tok->st_pos = 0;
state = json_tokener_state_escape_unicode;
break;
default:
tok->err = json_tokener_error_parse_string;
goto out;
}
break;
case json_tokener_state_escape_unicode:
{
unsigned int got_hi_surrogate = 0;
/* Handle a 4-byte sequence, or two sequences if a surrogate pair */
while(1) {
if(strchr(json_hex_chars, c)) {
tok->ucs_char += ((unsigned int)hexdigit(c) << ((3-tok->st_pos++)*4));
if(tok->st_pos == 4) {
unsigned char unescaped_utf[4];
if (got_hi_surrogate) {
if (IS_LOW_SURROGATE(tok->ucs_char)) {
/* Recalculate the ucs_char, then fall thru to process normally */
tok->ucs_char = DECODE_SURROGATE_PAIR(got_hi_surrogate, tok->ucs_char);
} else {
/* Hi surrogate was not followed by a low surrogate */
/* Replace the hi and process the rest normally */
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
}
got_hi_surrogate = 0;
}
if (tok->ucs_char < 0x80) {
unescaped_utf[0] = tok->ucs_char;
printbuf_memappend_fast(tok->pb, (char*)unescaped_utf, 1);
} else if (tok->ucs_char < 0x800) {
unescaped_utf[0] = 0xc0 | (tok->ucs_char >> 6);
unescaped_utf[1] = 0x80 | (tok->ucs_char & 0x3f);
printbuf_memappend_fast(tok->pb, (char*)unescaped_utf, 2);
} else if (IS_HIGH_SURROGATE(tok->ucs_char)) {
/* Got a high surrogate. Remember it and look for the
* the beginning of another sequence, which should be the
* low surrogate.
*/
got_hi_surrogate = tok->ucs_char;
/* Not at end, and the next two chars should be "\u" */
if ((tok->char_offset+1 != len) &&
(tok->char_offset+2 != len) &&
(str[1] == '\\') &&
(str[2] == 'u'))
{
ADVANCE_CHAR(str, tok);
ADVANCE_CHAR(str, tok);
/* Advance to the first char of the next sequence and
* continue processing with the next sequence.
*/
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
goto out;
}
tok->ucs_char = 0;
tok->st_pos = 0;
continue; /* other json_tokener_state_escape_unicode */
} else {
/* Got a high surrogate without another sequence following
* it. Put a replacement char in for the hi surrogate
* and pretend we finished.
*/
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
}
} else if (IS_LOW_SURROGATE(tok->ucs_char)) {
/* Got a low surrogate not preceded by a high */
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
} else if (tok->ucs_char < 0x10000) {
unescaped_utf[0] = 0xe0 | (tok->ucs_char >> 12);
unescaped_utf[1] = 0x80 | ((tok->ucs_char >> 6) & 0x3f);
unescaped_utf[2] = 0x80 | (tok->ucs_char & 0x3f);
printbuf_memappend_fast(tok->pb, (char*)unescaped_utf, 3);
} else if (tok->ucs_char < 0x110000) {
unescaped_utf[0] = 0xf0 | ((tok->ucs_char >> 18) & 0x07);
unescaped_utf[1] = 0x80 | ((tok->ucs_char >> 12) & 0x3f);
unescaped_utf[2] = 0x80 | ((tok->ucs_char >> 6) & 0x3f);
unescaped_utf[3] = 0x80 | (tok->ucs_char & 0x3f);
printbuf_memappend_fast(tok->pb, (char*)unescaped_utf, 4);
} else {
/* Don't know what we got--insert the replacement char */
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
}
state = saved_state;
break;
}
} else {
tok->err = json_tokener_error_parse_string;
goto out;
}
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
if (got_hi_surrogate) /* Clean up any pending chars */
printbuf_memappend_fast(tok->pb, (char*)utf8_replacement_char, 3);
goto out;
}
}
}
break;
case json_tokener_state_boolean:
printbuf_memappend_fast(tok->pb, &c, 1);
if(strncasecmp(json_true_str, tok->pb->buf,
json_min(tok->st_pos+1, strlen(json_true_str))) == 0) {
if(tok->st_pos == strlen(json_true_str)) {
current = json_object_new_boolean(1);
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
goto redo_char;
}
} else if(strncasecmp(json_false_str, tok->pb->buf,
json_min(tok->st_pos+1, strlen(json_false_str))) == 0) {
if(tok->st_pos == strlen(json_false_str)) {
current = json_object_new_boolean(0);
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
goto redo_char;
}
} else {
tok->err = json_tokener_error_parse_boolean;
goto out;
}
tok->st_pos++;
break;
case json_tokener_state_number:
{
/* Advance until we change state */
const char *case_start = str;
int case_len=0;
while(c && strchr(json_number_chars, c)) {
++case_len;
if(c == '.' || c == 'e') tok->is_double = 1;
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, case_start, case_len);
goto out;
}
}
if (case_len>0)
printbuf_memappend_fast(tok->pb, case_start, case_len);
}
{
int64_t num64;
double numd;
if (!tok->is_double && json_parse_int64(tok->pb->buf, &num64) == 0) {
current = json_object_new_int64(num64);
} else if(tok->is_double && sscanf(tok->pb->buf, "%lf", &numd) == 1) {
current = json_object_new_double(numd);
} else {
tok->err = json_tokener_error_parse_number;
goto out;
}
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
goto redo_char;
}
break;
case json_tokener_state_array:
if(c == ']') {
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
} else {
if(tok->depth >= JSON_TOKENER_MAX_DEPTH-1) {
tok->err = json_tokener_error_depth;
goto out;
}
state = json_tokener_state_array_add;
tok->depth++;
json_tokener_reset_level(tok, tok->depth);
goto redo_char;
}
break;
case json_tokener_state_array_add:
json_object_array_add(current, obj);
saved_state = json_tokener_state_array_sep;
state = json_tokener_state_eatws;
goto redo_char;
case json_tokener_state_array_sep:
if(c == ']') {
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
} else if(c == ',') {
saved_state = json_tokener_state_array;
state = json_tokener_state_eatws;
} else {
tok->err = json_tokener_error_parse_array;
goto out;
}
break;
case json_tokener_state_object_field_start:
if(c == '}') {
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
} else if (c == '"' || c == '\'') {
tok->quote_char = c;
printbuf_reset(tok->pb);
state = json_tokener_state_object_field;
} else {
tok->err = json_tokener_error_parse_object_key_name;
goto out;
}
break;
case json_tokener_state_object_field:
{
/* Advance until we change state */
const char *case_start = str;
while(1) {
if(c == tok->quote_char) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
obj_field_name = strdup(tok->pb->buf);
saved_state = json_tokener_state_object_field_end;
state = json_tokener_state_eatws;
break;
} else if(c == '\\') {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
saved_state = json_tokener_state_object_field;
state = json_tokener_state_string_escape;
break;
}
if (!ADVANCE_CHAR(str, tok) || !POP_CHAR(c, tok)) {
printbuf_memappend_fast(tok->pb, case_start, str-case_start);
goto out;
}
}
}
break;
case json_tokener_state_object_field_end:
if(c == ':') {
saved_state = json_tokener_state_object_value;
state = json_tokener_state_eatws;
} else {
tok->err = json_tokener_error_parse_object_key_sep;
goto out;
}
break;
case json_tokener_state_object_value:
if(tok->depth >= JSON_TOKENER_MAX_DEPTH-1) {
tok->err = json_tokener_error_depth;
goto out;
}
state = json_tokener_state_object_value_add;
tok->depth++;
json_tokener_reset_level(tok, tok->depth);
goto redo_char;
case json_tokener_state_object_value_add:
json_object_object_add(current, obj_field_name, obj);
free(obj_field_name);
obj_field_name = NULL;
saved_state = json_tokener_state_object_sep;
state = json_tokener_state_eatws;
goto redo_char;
case json_tokener_state_object_sep:
if(c == '}') {
saved_state = json_tokener_state_finish;
state = json_tokener_state_eatws;
} else if(c == ',') {
saved_state = json_tokener_state_object_field_start;
state = json_tokener_state_eatws;
} else {
tok->err = json_tokener_error_parse_object_value_sep;
goto out;
}
break;
}
if (!ADVANCE_CHAR(str, tok))
goto out;
} /* while(POP_CHAR) */
out:
if (!c) { /* We hit an eof char (0) */
if(state != json_tokener_state_finish &&
saved_state != json_tokener_state_finish)
tok->err = json_tokener_error_parse_eof;
}
if(tok->err == json_tokener_success) return json_object_get(current);
MC_DEBUG("json_tokener_parse_ex: error %s at offset %d\n",
json_tokener_errors[tok->err], tok->char_offset);
return NULL;
}
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