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/* vim: set et ts=3 sw=3 ft=c:
*
* Copyright (C) 2012 James McLaughlin et al. All rights reserved.
* https://github.com/udp/json-parser
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "json.h"
#ifdef _MSC_VER
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#endif
#endif
#ifdef __cplusplus
const struct _json_value json_value_none; /* zero-d by ctor */
#else
const struct _json_value json_value_none = { 0 };
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
typedef unsigned short json_uchar;
static unsigned char hex_value (json_char c)
{
if (c >= 'A' && c <= 'F')
return (c - 'A') + 10;
if (c >= 'a' && c <= 'f')
return (c - 'a') + 10;
if (c >= '0' && c <= '9')
return c - '0';
return 0xFF;
}
typedef struct
{
json_settings settings;
int first_pass;
unsigned long used_memory;
unsigned int uint_max;
unsigned long ulong_max;
} json_state;
static void * json_alloc (json_state * state, unsigned long size, int zero)
{
void * mem;
if ((state->ulong_max - state->used_memory) < size)
return 0;
if (state->settings.max_memory
&& (state->used_memory += size) > state->settings.max_memory)
{
return 0;
}
if (! (mem = zero ? calloc (size, 1) : malloc (size)))
return 0;
return mem;
}
static int new_value
(json_state * state, json_value ** top, json_value ** root, json_value ** alloc, json_type type)
{
json_value * value;
int values_size;
if (!state->first_pass)
{
value = *top = *alloc;
*alloc = (*alloc)->_reserved.next_alloc;
if (!*root)
*root = value;
switch (value->type)
{
case json_array:
if (! (value->u.array.values = (json_value **) json_alloc
(state, value->u.array.length * sizeof (json_value *), 0)) )
{
return 0;
}
break;
case json_object:
values_size = sizeof (*value->u.object.values) * value->u.object.length;
if (! ((*(void **) &value->u.object.values) = json_alloc
(state, values_size + ((unsigned long) value->u.object.values), 0)) )
{
return 0;
}
value->_reserved.object_mem = (*(char **) &value->u.object.values) + values_size;
break;
case json_string:
if (! (value->u.string.ptr = (json_char *) json_alloc
(state, (value->u.string.length + 1) * sizeof (json_char), 0)) )
{
return 0;
}
break;
default:
break;
};
value->u.array.length = 0;
return 1;
}
value = (json_value *) json_alloc (state, sizeof (json_value), 1);
if (!value)
return 0;
if (!*root)
*root = value;
value->type = type;
value->parent = *top;
if (*alloc)
(*alloc)->_reserved.next_alloc = value;
*alloc = *top = value;
return 1;
}
#define e_off \
((int) (i - cur_line_begin))
#define whitespace \
case '\n': ++ cur_line; cur_line_begin = i; \
case ' ': case '\t': case '\r'
#define string_add(b) \
do { if (!state.first_pass) string [string_length] = b; ++ string_length; } while (0);
const static int
flag_next = 1, flag_reproc = 2, flag_need_comma = 4, flag_seek_value = 8, flag_exponent = 16,
flag_got_exponent_sign = 32, flag_escaped = 64, flag_string = 128, flag_need_colon = 256,
flag_done = 512;
json_value * json_parse_ex (json_settings * settings, const json_char * json, char * error_buf)
{
json_char error [128];
unsigned int cur_line;
const json_char * cur_line_begin, * i;
json_value * top, * root, * alloc = 0;
json_state state;
int flags;
error[0] = '\0';
memset (&state, 0, sizeof (json_state));
memcpy (&state.settings, settings, sizeof (json_settings));
memset (&state.uint_max, 0xFF, sizeof (state.uint_max));
memset (&state.ulong_max, 0xFF, sizeof (state.ulong_max));
state.uint_max -= 8; /* limit of how much can be added before next check */
state.ulong_max -= 8;
for (state.first_pass = 1; state.first_pass >= 0; -- state.first_pass)
{
json_uchar uchar;
unsigned char uc_b1, uc_b2, uc_b3, uc_b4;
json_char * string;
unsigned int string_length;
top = root = 0;
flags = flag_seek_value;
cur_line = 1;
cur_line_begin = json;
for (i = json ;; ++ i)
{
json_char b = *i;
if (flags & flag_done)
{
if (!b)
break;
switch (b)
{
whitespace:
continue;
default:
sprintf (error, "%d:%d: Trailing garbage: `%c`", cur_line, e_off, b);
goto e_failed;
};
}
if (flags & flag_string)
{
if (!b)
{ sprintf (error, "Unexpected EOF in string (at %d:%d)", cur_line, e_off);
goto e_failed;
}
if (string_length > state.uint_max)
goto e_overflow;
if (flags & flag_escaped)
{
flags &= ~ flag_escaped;
switch (b)
{
case 'b': string_add ('\b'); break;
case 'f': string_add ('\f'); break;
case 'n': string_add ('\n'); break;
case 'r': string_add ('\r'); break;
case 't': string_add ('\t'); break;
case 'u':
if ((uc_b1 = hex_value (*++ i)) == 0xFF || (uc_b2 = hex_value (*++ i)) == 0xFF
|| (uc_b3 = hex_value (*++ i)) == 0xFF || (uc_b4 = hex_value (*++ i)) == 0xFF)
{
sprintf (error, "Invalid character value `%c` (at %d:%d)", b, cur_line, e_off);
goto e_failed;
}
uc_b1 = uc_b1 * 16 + uc_b2;
uc_b2 = uc_b3 * 16 + uc_b4;
uchar = ((json_char) uc_b1) * 256 + uc_b2;
if (sizeof (json_char) >= sizeof (json_uchar) || (uc_b1 == 0 && uc_b2 <= 0x7F))
{
string_add ((json_char) uchar);
break;
}
if (uchar <= 0x7FF)
{
if (state.first_pass)
string_length += 2;
else
{ string [string_length ++] = 0xC0 | ((uc_b2 & 0xC0) >> 6) | ((uc_b1 & 0x3) << 3);
string [string_length ++] = 0x80 | (uc_b2 & 0x3F);
}
break;
}
if (state.first_pass)
string_length += 3;
else
{ string [string_length ++] = 0xE0 | ((uc_b1 & 0xF0) >> 4);
string [string_length ++] = 0x80 | ((uc_b1 & 0xF) << 2) | ((uc_b2 & 0xC0) >> 6);
string [string_length ++] = 0x80 | (uc_b2 & 0x3F);
}
break;
default:
string_add (b);
};
continue;
}
if (b == '\\')
{
flags |= flag_escaped;
continue;
}
if (b == '"')
{
if (!state.first_pass)
string [string_length] = 0;
flags &= ~ flag_string;
string = 0;
switch (top->type)
{
case json_string:
top->u.string.length = string_length;
flags |= flag_next;
break;
case json_object:
if (state.first_pass)
(*(json_char **) &top->u.object.values) += string_length + 1;
else
{
top->u.object.values [top->u.object.length].name
= (json_char *) top->_reserved.object_mem;
(*(json_char **) &top->_reserved.object_mem) += string_length + 1;
}
flags |= flag_seek_value | flag_need_colon;
continue;
default:
break;
};
}
else
{
string_add (b);
continue;
}
}
if (flags & flag_seek_value)
{
switch (b)
{
whitespace:
continue;
case ']':
if (top->type == json_array)
flags = (flags & ~ (flag_need_comma | flag_seek_value)) | flag_next;
else if (!state.settings.settings & json_relaxed_commas)
{ sprintf (error, "%d:%d: Unexpected ]", cur_line, e_off);
goto e_failed;
}
break;
default:
if (flags & flag_need_comma)
{
if (b == ',')
{ flags &= ~ flag_need_comma;
continue;
}
else
{ sprintf (error, "%d:%d: Expected , before %c", cur_line, e_off, b);
goto e_failed;
}
}
if (flags & flag_need_colon)
{
if (b == ':')
{ flags &= ~ flag_need_colon;
continue;
}
else
{ sprintf (error, "%d:%d: Expected : before %c", cur_line, e_off, b);
goto e_failed;
}
}
flags &= ~ flag_seek_value;
switch (b)
{
case '{':
if (!new_value (&state, &top, &root, &alloc, json_object))
goto e_alloc_failure;
continue;
case '[':
if (!new_value (&state, &top, &root, &alloc, json_array))
goto e_alloc_failure;
flags |= flag_seek_value;
continue;
case '"':
if (!new_value (&state, &top, &root, &alloc, json_string))
goto e_alloc_failure;
flags |= flag_string;
string = top->u.string.ptr;
string_length = 0;
continue;
case 't':
if (*(++ i) != 'r' || *(++ i) != 'u' || *(++ i) != 'e')
goto e_unknown_value;
if (!new_value (&state, &top, &root, &alloc, json_boolean))
goto e_alloc_failure;
top->u.boolean = 1;
flags |= flag_next;
break;
case 'f':
if (*(++ i) != 'a' || *(++ i) != 'l' || *(++ i) != 's' || *(++ i) != 'e')
goto e_unknown_value;
if (!new_value (&state, &top, &root, &alloc, json_boolean))
goto e_alloc_failure;
flags |= flag_next;
break;
case 'n':
if (*(++ i) != 'u' || *(++ i) != 'l' || *(++ i) != 'l')
goto e_unknown_value;
if (!new_value (&state, &top, &root, &alloc, json_null))
goto e_alloc_failure;
flags |= flag_next;
break;
default:
if (isdigit (b) || b == '-')
{
if (!new_value (&state, &top, &root, &alloc, json_integer))
goto e_alloc_failure;
flags &= ~ (flag_exponent | flag_got_exponent_sign);
if (state.first_pass)
continue;
if (top->type == json_double)
top->u.dbl = strtod (i, (json_char **) &i);
else
top->u.integer = strtol (i, (json_char **) &i, 10);
flags |= flag_next | flag_reproc;
}
else
{ sprintf (error, "%d:%d: Unexpected %c when seeking value", cur_line, e_off, b);
goto e_failed;
}
};
};
}
else
{
switch (top->type)
{
case json_object:
switch (b)
{
whitespace:
continue;
case '"':
if (flags & flag_need_comma && (!state.settings.settings & json_relaxed_commas))
{
sprintf (error, "%d:%d: Expected , before \"", cur_line, e_off);
goto e_failed;
}
flags |= flag_string;
string = (json_char *) top->_reserved.object_mem;
string_length = 0;
break;
case '}':
flags = (flags & ~ flag_need_comma) | flag_next;
break;
case ',':
if (flags & flag_need_comma)
{
flags &= ~ flag_need_comma;
break;
}
default:
sprintf (error, "%d:%d: Unexpected `%c` in object", cur_line, e_off, b);
goto e_failed;
};
break;
case json_integer:
case json_double:
if (isdigit (b))
continue;
if (b == 'e' || b == 'E')
{
if (!(flags & flag_exponent))
{
flags |= flag_exponent;
top->type = json_double;
continue;
}
}
else if (b == '+' || b == '-')
{
if (flags & flag_exponent && !(flags & flag_got_exponent_sign))
{
flags |= flag_got_exponent_sign;
continue;
}
}
else if (b == '.' && top->type == json_integer)
{
top->type = json_double;
continue;
}
flags |= flag_next | flag_reproc;
break;
default:
break;
};
}
if (flags & flag_reproc)
{
flags &= ~ flag_reproc;
-- i;
}
if (flags & flag_next)
{
flags = (flags & ~ flag_next) | flag_need_comma;
if (!top->parent)
{
/* root value done */
flags |= flag_done;
continue;
}
if (top->parent->type == json_array)
flags |= flag_seek_value;
if (!state.first_pass)
{
json_value * parent = top->parent;
switch (parent->type)
{
case json_object:
parent->u.object.values
[parent->u.object.length].value = top;
break;
case json_array:
parent->u.array.values
[parent->u.array.length] = top;
break;
default:
break;
};
}
if ( (++ top->parent->u.array.length) > state.uint_max)
goto e_overflow;
top = top->parent;
continue;
}
}
alloc = root;
}
return root;
e_unknown_value:
sprintf (error, "%d:%d: Unknown value", cur_line, e_off);
goto e_failed;
e_alloc_failure:
strcpy (error, "Memory allocation failure");
goto e_failed;
e_overflow:
sprintf (error, "%d:%d: Too long (caught overflow)", cur_line, e_off);
goto e_failed;
e_failed:
if (error_buf)
{
if (*error)
strcpy (error_buf, error);
else
strcpy (error_buf, "Unknown error");
}
if (state.first_pass)
alloc = root;
while (alloc)
{
top = alloc->_reserved.next_alloc;
free (alloc);
alloc = top;
}
if (!state.first_pass)
json_value_free (root);
return 0;
}
json_value * json_parse (const json_char * json)
{
json_settings settings;
memset (&settings, 0, sizeof (json_settings));
return json_parse_ex (&settings, json, 0);
}
void json_value_free (json_value * value)
{
json_value * cur_value;
if (!value)
return;
value->parent = 0;
while (value)
{
switch (value->type)
{
case json_array:
if (!value->u.array.length)
{
free (value->u.array.values);
break;
}
value = value->u.array.values [-- value->u.array.length];
continue;
case json_object:
if (!value->u.object.length)
{
free (value->u.object.values);
break;
}
value = value->u.object.values [-- value->u.object.length].value;
continue;
case json_string:
free (value->u.string.ptr);
break;
default:
break;
};
cur_value = value;
value = value->parent;
free (cur_value);
}
}