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CS GO JSON PARSER
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JSON_parser.c
/*
Copyright (c) 2005 JSON.org
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
The Software shall be used for Good, not Evil.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
/*
Callbacks, comments, Unicode handling by Jean Gressmann (jean@0x42.de), 2007-2010.
Changelog:
2010-11-25
Support for custom memory allocation (sgbeal@googlemail.com).
2010-05-07
Added error handling for memory allocation failure (sgbeal@googlemail.com).
Added diagnosis errors for invalid JSON.
2010-03-25
Fixed buffer overrun in grow_parse_buffer & cleaned up code.
2009-10-19
Replaced long double in JSON_value_struct with double after reports
of strtold being broken on some platforms (charles@transmissionbt.com).
2009-05-17
Incorporated benrudiak@googlemail.com fix for UTF16 decoding.
2009-05-14
Fixed float parsing bug related to a locale being set that didn't
use '.' as decimal point character (charles@transmissionbt.com).
2008-10-14
Renamed states.IN to states.IT to avoid name clash which IN macro
defined in windef.h (alexey.pelykh@gmail.com)
2008-07-19
Removed some duplicate code & debugging variable (charles@transmissionbt.com)
2008-05-28
Made JSON_value structure ansi C compliant. This bug was report by
trisk@acm.jhu.edu
2008-05-20
Fixed bug reported by charles@transmissionbt.com where the switching
from static to dynamic parse buffer did not copy the static parse
buffer's content.
*/
#include <assert.h>
#include <ctype.h>
#include <float.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include "JSON_parser.h"
#ifdef _MSC_VER
# if _MSC_VER >= 1400 /* Visual Studio 2005 and up */
# pragma warning(disable:4996) /* unsecure sscanf */
# pragma warning(disable:4127) /* conditional expression is constant */
# endif
#endif
#define true 1
#define false 0
#define __ -1 /* the universal error code */
/* values chosen so that the object size is approx equal to one page (4K) */
#ifndef JSON_PARSER_STACK_SIZE
# define JSON_PARSER_STACK_SIZE 128
#endif
#ifndef JSON_PARSER_PARSE_BUFFER_SIZE
# define JSON_PARSER_PARSE_BUFFER_SIZE 3500
#endif
typedef void* (*JSON_debug_malloc_t)(size_t bytes, const char* reason);
#ifdef JSON_PARSER_DEBUG_MALLOC
# define JSON_parser_malloc(func, bytes, reason) ((JSON_debug_malloc_t)func)(bytes, reason)
#else
# undef JSON_parser_malloc
# define JSON_parser_malloc(func, bytes, reason) func(bytes)
#endif
typedef unsigned short UTF16;
struct JSON_parser_struct {
JSON_parser_callback callback;
void* ctx;
signed char state, before_comment_state, type, escaped, comment, allow_comments, handle_floats_manually, error;
char decimal_point;
UTF16 utf16_high_surrogate;
int current_char;
int depth;
int top;
int stack_capacity;
signed char* stack;
char* parse_buffer;
size_t parse_buffer_capacity;
size_t parse_buffer_count;
signed char static_stack[JSON_PARSER_STACK_SIZE];
char static_parse_buffer[JSON_PARSER_PARSE_BUFFER_SIZE];
JSON_malloc_t malloc;
JSON_free_t free;
};
#define COUNTOF(x) (sizeof(x)/sizeof(x[0]))
/*
Characters are mapped into these character classes. This allows for
a significant reduction in the size of the state transition table.
*/
enum classes {
C_SPACE, /* space */
C_WHITE, /* other whitespace */
C_LCURB, /* { */
C_RCURB, /* } */
C_LSQRB, /* [ */
C_RSQRB, /* ] */
C_COLON, /* : */
C_COMMA, /* , */
C_QUOTE, /* " */
C_BACKS, /* \ */
C_SLASH, /* / */
C_PLUS, /* + */
C_MINUS, /* - */
C_POINT, /* . */
C_ZERO , /* 0 */
C_DIGIT, /* 123456789 */
C_LOW_A, /* a */
C_LOW_B, /* b */
C_LOW_C, /* c */
C_LOW_D, /* d */
C_LOW_E, /* e */
C_LOW_F, /* f */
C_LOW_L, /* l */
C_LOW_N, /* n */
C_LOW_R, /* r */
C_LOW_S, /* s */
C_LOW_T, /* t */
C_LOW_U, /* u */
C_ABCDF, /* ABCDF */
C_E, /* E */
C_ETC, /* everything else */
C_STAR, /* * */
NR_CLASSES
};
static const signed char ascii_class[128] = {
/*
This array maps the 128 ASCII characters into character classes.
The remaining Unicode characters should be mapped to C_ETC.
Non-whitespace control characters are errors.
*/
__, __, __, __, __, __, __, __,
__, C_WHITE, C_WHITE, __, __, C_WHITE, __, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __,
C_SPACE, C_ETC, C_QUOTE, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_STAR, C_PLUS, C_COMMA, C_MINUS, C_POINT, C_SLASH,
C_ZERO, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT,
C_DIGIT, C_DIGIT, C_COLON, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ABCDF, C_ABCDF, C_ABCDF, C_ABCDF, C_E, C_ABCDF, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_LSQRB, C_BACKS, C_RSQRB, C_ETC, C_ETC,
C_ETC, C_LOW_A, C_LOW_B, C_LOW_C, C_LOW_D, C_LOW_E, C_LOW_F, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_LOW_L, C_ETC, C_LOW_N, C_ETC,
C_ETC, C_ETC, C_LOW_R, C_LOW_S, C_LOW_T, C_LOW_U, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_LCURB, C_ETC, C_RCURB, C_ETC, C_ETC
};
/*
The state codes.
*/
enum states {
GO, /* start */
OK, /* ok */
OB, /* object */
KE, /* key */
CO, /* colon */
VA, /* value */
AR, /* array */
ST, /* string */
ES, /* escape */
U1, /* u1 */
U2, /* u2 */
U3, /* u3 */
U4, /* u4 */
MI, /* minus */
ZE, /* zero */
IT, /* integer */
FR, /* fraction */
E1, /* e */
E2, /* ex */
E3, /* exp */
T1, /* tr */
T2, /* tru */
T3, /* true */
F1, /* fa */
F2, /* fal */
F3, /* fals */
F4, /* false */
N1, /* nu */
N2, /* nul */
N3, /* null */
C1, /* / */
C2, /* / * */
C3, /* * */
FX, /* *.* *eE* */
D1, /* second UTF-16 character decoding started by \ */
D2, /* second UTF-16 character proceeded by u */
NR_STATES
};
enum actions
{
CB = -10, /* comment begin */
CE = -11, /* comment end */
FA = -12, /* false */
TR = -13, /* false */
NU = -14, /* null */
DE = -15, /* double detected by exponent e E */
DF = -16, /* double detected by fraction . */
SB = -17, /* string begin */
MX = -18, /* integer detected by minus */
ZX = -19, /* integer detected by zero */
IX = -20, /* integer detected by 1-9 */
EX = -21, /* next char is escaped */
UC = -22 /* Unicode character read */
};
static const signed char state_transition_table[NR_STATES][NR_CLASSES] = {
/*
The state transition table takes the current state and the current symbol,
and returns either a new state or an action. An action is represented as a
negative number. A JSON text is accepted if at the end of the text the
state is OK and if the mode is MODE_DONE.
white 1-9 ABCDF etc
space | { } [ ] : , " \ / + - . 0 | a b c d e f l n r s t u | E | * */
/*start GO*/ {GO,GO,-6,__,-5,__,__,__,__,__,CB,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*ok OK*/ {OK,OK,__,-8,__,-7,__,-3,__,__,CB,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*object OB*/ {OB,OB,__,-9,__,__,__,__,SB,__,CB,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*key KE*/ {KE,KE,__,__,__,__,__,__,SB,__,CB,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*colon CO*/ {CO,CO,__,__,__,__,-2,__,__,__,CB,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*value VA*/ {VA,VA,-6,__,-5,__,__,__,SB,__,CB,__,MX,__,ZX,IX,__,__,__,__,__,FA,__,NU,__,__,TR,__,__,__,__,__},
/*array AR*/ {AR,AR,-6,__,-5,-7,__,__,SB,__,CB,__,MX,__,ZX,IX,__,__,__,__,__,FA,__,NU,__,__,TR,__,__,__,__,__},
/*string ST*/ {ST,__,ST,ST,ST,ST,ST,ST,-4,EX,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST},
/*escape ES*/ {__,__,__,__,__,__,__,__,ST,ST,ST,__,__,__,__,__,__,ST,__,__,__,ST,__,ST,ST,__,ST,U1,__,__,__,__},
/*u1 U1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U2,U2,U2,U2,U2,U2,U2,U2,__,__,__,__,__,__,U2,U2,__,__},
/*u2 U2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U3,U3,U3,U3,U3,U3,U3,U3,__,__,__,__,__,__,U3,U3,__,__},
/*u3 U3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U4,U4,U4,U4,U4,U4,U4,U4,__,__,__,__,__,__,U4,U4,__,__},
/*u4 U4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,UC,UC,UC,UC,UC,UC,UC,UC,__,__,__,__,__,__,UC,UC,__,__},
/*minus MI*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,ZE,IT,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*zero ZE*/ {OK,OK,__,-8,__,-7,__,-3,__,__,CB,__,__,DF,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*int IT*/ {OK,OK,__,-8,__,-7,__,-3,__,__,CB,__,__,DF,IT,IT,__,__,__,__,DE,__,__,__,__,__,__,__,__,DE,__,__},
/*frac FR*/ {OK,OK,__,-8,__,-7,__,-3,__,__,CB,__,__,__,FR,FR,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__,__},
/*e E1*/ {__,__,__,__,__,__,__,__,__,__,__,E2,E2,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*ex E2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*exp E3*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*tr T1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T2,__,__,__,__,__,__,__},
/*tru T2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T3,__,__,__,__},
/*true T3*/ {__,__,__,__,__,__,__,__,__,__,CB,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__,__},
/*fa F1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F2,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*fal F2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F3,__,__,__,__,__,__,__,__,__},
/*fals F3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F4,__,__,__,__,__,__},
/*false F4*/ {__,__,__,__,__,__,__,__,__,__,CB,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__,__},
/*nu N1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N2,__,__,__,__},
/*nul N2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N3,__,__,__,__,__,__,__,__,__},
/*null N3*/ {__,__,__,__,__,__,__,__,__,__,CB,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__},
/*/ C1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,C2},
/*/* C2*/ {C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C3},
/** C3*/ {C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,CE,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C3},
/*_. FX*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,__,FR,FR,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__,__},
/*\ D1*/ {__,__,__,__,__,__,__,__,__,D2,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
/*\ D2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,U1,__,__,__,__},
};
/*
These modes can be pushed on the stack.
*/
enum modes {
MODE_ARRAY = 1,
MODE_DONE = 2,
MODE_KEY = 3,
MODE_OBJECT = 4
};
static void set_error(JSON_parser jc)
{
switch (jc->state) {
case GO:
switch (jc->current_char) {
case '{': case '}': case '[': case ']':
jc->error = JSON_E_UNBALANCED_COLLECTION;
break;
default:
jc->error = JSON_E_INVALID_CHAR;
break;
}
break;
case OB:
jc->error = JSON_E_EXPECTED_KEY;
break;
case AR:
jc->error = JSON_E_UNBALANCED_COLLECTION;
break;
case CO:
jc->error = JSON_E_EXPECTED_COLON;
break;
case KE:
jc->error = JSON_E_EXPECTED_KEY;
break;
/* \uXXXX\uYYYY */
case U1: case U2: case U3: case U4: case D1: case D2:
jc->error = JSON_E_INVALID_UNICODE_SEQUENCE;
break;
/* true, false, null */
case T1: case T2: case T3: case F1: case F2: case F3: case F4: case N1: case N2: case N3:
jc->error = JSON_E_INVALID_KEYWORD;
break;
/* minus, integer, fraction, exponent */
case MI: case ZE: case IT: case FR: case E1: case E2: case E3:
jc->error = JSON_E_INVALID_NUMBER;
break;
default:
jc->error = JSON_E_INVALID_CHAR;
break;
}
}
static int
push(JSON_parser jc, int mode)
{
/*
Push a mode onto the stack. Return false if there is overflow.
*/
assert(jc->top <= jc->stack_capacity);
if (jc->depth < 0) {
if (jc->top == jc->stack_capacity) {
const size_t bytes_to_copy = jc->stack_capacity * sizeof(jc->stack[0]);
const size_t new_capacity = jc->stack_capacity * 2;
const size_t bytes_to_allocate = new_capacity * sizeof(jc->stack[0]);
void* mem = JSON_parser_malloc(jc->malloc, bytes_to_allocate, "stack");
if (!mem) {
jc->error = JSON_E_OUT_OF_MEMORY;
return false;
}
jc->stack_capacity = (int)new_capacity;
memcpy(mem, jc->stack, bytes_to_copy);
if (jc->stack != &jc->static_stack[0]) {
jc->free(jc->stack);
}
jc->stack = (signed char*)mem;
}
} else {
if (jc->top == jc->depth) {
jc->error = JSON_E_NESTING_DEPTH_REACHED;
return false;
}
}
jc->stack[++jc->top] = (signed char)mode;
return true;
}
static int
pop(JSON_parser jc, int mode)
{
/*
Pop the stack, assuring that the current mode matches the expectation.
Return false if there is underflow or if the modes mismatch.
*/
if (jc->top < 0 || jc->stack[jc->top] != mode) {
return false;
}
jc->top -= 1;
return true;
}
#define parse_buffer_clear(jc) \
do {\
jc->parse_buffer_count = 0;\
jc->parse_buffer[0] = 0;\
} while (0)
#define parse_buffer_pop_back_char(jc)\
do {\
assert(jc->parse_buffer_count >= 1);\
--jc->parse_buffer_count;\
jc->parse_buffer[jc->parse_buffer_count] = 0;\
} while (0)
void delete_JSON_parser(JSON_parser jc)
{
if (jc) {
if (jc->stack != &jc->static_stack[0]) {
jc->free((void*)jc->stack);
}
if (jc->parse_buffer != &jc->static_parse_buffer[0]) {
jc->free((void*)jc->parse_buffer);
}
jc->free((void*)jc);
}
}
int JSON_parser_reset(JSON_parser jc)
{
if (NULL == jc) {
return false;
}
jc->state = GO;
jc->top = -1;
/* parser has been used previously? */
if (NULL == jc->parse_buffer) {
/* Do we want non-bound stack? */
if (jc->depth > 0) {
jc->stack_capacity = jc->depth;
if (jc->depth <= (int)COUNTOF(jc->static_stack)) {
jc->stack = &jc->static_stack[0];
} else {
const size_t bytes_to_alloc = jc->stack_capacity * sizeof(jc->stack[0]);
jc->stack = (signed char*)JSON_parser_malloc(jc->malloc, bytes_to_alloc, "stack");
if (jc->stack == NULL) {
return false;
}
}
} else {
jc->stack_capacity = (int)COUNTOF(jc->static_stack);
jc->depth = -1;
jc->stack = &jc->static_stack[0];
}
/* set up the parse buffer */
jc->parse_buffer = &jc->static_parse_buffer[0];
jc->parse_buffer_capacity = COUNTOF(jc->static_parse_buffer);
}
/* set parser to start */
push(jc, MODE_DONE);
parse_buffer_clear(jc);
return true;
}
JSON_parser
new_JSON_parser(JSON_config const * config)
{
/*
new_JSON_parser starts the checking process by constructing a JSON_parser
object. It takes a depth parameter that restricts the level of maximum
nesting.
To continue the process, call JSON_parser_char for each character in the
JSON text, and then call JSON_parser_done to obtain the final result.
These functions are fully reentrant.
*/
int use_std_malloc = false;
JSON_config default_config;
JSON_parser jc;
JSON_malloc_t alloc;
/* set to default configuration if none was provided */
if (NULL == config) {
/* initialize configuration */
init_JSON_config(&default_config);
config = &default_config;
}
/* use std malloc if either the allocator or deallocator function isn't set */
use_std_malloc = NULL == config->malloc || NULL == config->free;
alloc = use_std_malloc ? malloc : config->malloc;
jc = (JSON_parser)JSON_parser_malloc(alloc, sizeof(*jc), "parser");
if (NULL == jc) {
return NULL;
}
/* configure the parser */
memset(jc, 0, sizeof(*jc));
jc->malloc = alloc;
jc->free = use_std_malloc ? free : config->free;
jc->callback = config->callback;
jc->ctx = config->callback_ctx;
jc->allow_comments = (signed char)(config->allow_comments != 0);
jc->handle_floats_manually = (signed char)(config->handle_floats_manually != 0);
jc->decimal_point = *localeconv()->decimal_point;
/* We need to be able to push at least one object */
jc->depth = config->depth == 0 ? 1 : config->depth;
/* reset the parser */
if (!JSON_parser_reset(jc)) {
jc->free(jc);
return NULL;
}
return jc;
}
static int parse_buffer_grow(JSON_parser jc)
{
const size_t bytes_to_copy = jc->parse_buffer_count * sizeof(jc->parse_buffer[0]);
const size_t new_capacity = jc->parse_buffer_capacity * 2;
const size_t bytes_to_allocate = new_capacity * sizeof(jc->parse_buffer[0]);
void* mem = JSON_parser_malloc(jc->malloc, bytes_to_allocate, "parse buffer");
if (mem == NULL) {
jc->error = JSON_E_OUT_OF_MEMORY;
return false;
}
assert(new_capacity > 0);
memcpy(mem, jc->parse_buffer, bytes_to_copy);
if (jc->parse_buffer != &jc->static_parse_buffer[0]) {
jc->free(jc->parse_buffer);
}
jc->parse_buffer = (char*)mem;
jc->parse_buffer_capacity = new_capacity;
return true;
}
static int parse_buffer_reserve_for(JSON_parser jc, unsigned chars)
{
while (jc->parse_buffer_count + chars + 1 > jc->parse_buffer_capacity) {
if (!parse_buffer_grow(jc)) {
assert(jc->error == JSON_E_OUT_OF_MEMORY);
return false;
}
}
return true;
}
#define parse_buffer_has_space_for(jc, count) \
(jc->parse_buffer_count + (count) + 1 <= jc->parse_buffer_capacity)
#define parse_buffer_push_back_char(jc, c)\
do {\
assert(parse_buffer_has_space_for(jc, 1)); \
jc->parse_buffer[jc->parse_buffer_count++] = c;\
jc->parse_buffer[jc->parse_buffer_count] = 0;\
} while (0)
#define assert_is_non_container_type(jc) \
assert( \
jc->type == JSON_T_NULL || \
jc->type == JSON_T_FALSE || \
jc->type == JSON_T_TRUE || \
jc->type == JSON_T_FLOAT || \
jc->type == JSON_T_INTEGER || \
jc->type == JSON_T_STRING)
static int parse_parse_buffer(JSON_parser jc)
{
if (jc->callback) {
JSON_value value, *arg = NULL;
if (jc->type != JSON_T_NONE) {
assert_is_non_container_type(jc);
switch(jc->type) {
case JSON_T_FLOAT:
arg = &value;
if (jc->handle_floats_manually) {
value.vu.str.value = jc->parse_buffer;
value.vu.str.length = jc->parse_buffer_count;
} else {
/* not checking with end pointer b/c there may be trailing ws */
value.vu.float_value = strtod(jc->parse_buffer, NULL);
}
break;
case JSON_T_INTEGER:
arg = &value;
sscanf(jc->parse_buffer, JSON_PARSER_INTEGER_SSCANF_TOKEN, &value.vu.integer_value);
break;
case JSON_T_STRING:
arg = &value;
value.vu.str.value = jc->parse_buffer;
value.vu.str.length = jc->parse_buffer_count;
break;
}
if (!(*jc->callback)(jc->ctx, jc->type, arg)) {
return false;
}
}
}
parse_buffer_clear(jc);
return true;
}
#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 const unsigned char utf8_lead_bits[4] = { 0x00, 0xC0, 0xE0, 0xF0 };
static int decode_unicode_char(JSON_parser jc)
{
int i;
unsigned uc = 0;
char* p;
int trail_bytes;
assert(jc->parse_buffer_count >= 6);
p = &jc->parse_buffer[jc->parse_buffer_count - 4];
for (i = 12; i >= 0; i -= 4, ++p) {
unsigned x = *p;
if (x >= 'a') {
x -= ('a' - 10);
} else if (x >= 'A') {
x -= ('A' - 10);
} else {
x &= ~0x30u;
}
assert(x < 16);
uc |= x << i;
}
/* clear UTF-16 char from buffer */
jc->parse_buffer_count -= 6;
jc->parse_buffer[jc->parse_buffer_count] = 0;
/* attempt decoding ... */
if (jc->utf16_high_surrogate) {
if (IS_LOW_SURROGATE(uc)) {
uc = DECODE_SURROGATE_PAIR(jc->utf16_high_surrogate, uc);
trail_bytes = 3;
jc->utf16_high_surrogate = 0;
} else {
/* high surrogate without a following low surrogate */
return false;
}
} else {
if (uc < 0x80) {
trail_bytes = 0;
} else if (uc < 0x800) {
trail_bytes = 1;
} else if (IS_HIGH_SURROGATE(uc)) {
/* save the high surrogate and wait for the low surrogate */
jc->utf16_high_surrogate = (UTF16)uc;
return true;
} else if (IS_LOW_SURROGATE(uc)) {
/* low surrogate without a preceding high surrogate */
return false;
} else {
trail_bytes = 2;
}
}
jc->parse_buffer[jc->parse_buffer_count++] = (char) ((uc >> (trail_bytes * 6)) | utf8_lead_bits[trail_bytes]);
for (i = trail_bytes * 6 - 6; i >= 0; i -= 6) {
jc->parse_buffer[jc->parse_buffer_count++] = (char) (((uc >> i) & 0x3F) | 0x80);
}
jc->parse_buffer[jc->parse_buffer_count] = 0;
return true;
}
static int add_escaped_char_to_parse_buffer(JSON_parser jc, int next_char)
{
assert(parse_buffer_has_space_for(jc, 1));
jc->escaped = 0;
/* remove the backslash */
parse_buffer_pop_back_char(jc);
switch(next_char) {
case 'b':
parse_buffer_push_back_char(jc, '\b');
break;
case 'f':
parse_buffer_push_back_char(jc, '\f');
break;
case 'n':
parse_buffer_push_back_char(jc, '\n');
break;
case 'r':
parse_buffer_push_back_char(jc, '\r');
break;
case 't':
parse_buffer_push_back_char(jc, '\t');
break;
case '"':
parse_buffer_push_back_char(jc, '"');
break;
case '\\':
parse_buffer_push_back_char(jc, '\\');
break;
case '/':
parse_buffer_push_back_char(jc, '/');
break;
case 'u':
parse_buffer_push_back_char(jc, '\\');
parse_buffer_push_back_char(jc, 'u');
break;
default:
return false;
}
return true;
}
static int add_char_to_parse_buffer(JSON_parser jc, int next_char, int next_class)
{
if (!parse_buffer_reserve_for(jc, 1)) {
assert(JSON_E_OUT_OF_MEMORY == jc->error);
return false;
}
if (jc->escaped) {
if (!add_escaped_char_to_parse_buffer(jc, next_char)) {
jc->error = JSON_E_INVALID_ESCAPE_SEQUENCE;
return false;
}
} else if (!jc->comment) {
if ((jc->type != JSON_T_NONE) | !((next_class == C_SPACE) | (next_class == C_WHITE)) /* non-white-space */) {
parse_buffer_push_back_char(jc, (char)next_char);
}
}
return true;
}
#define assert_type_isnt_string_null_or_bool(jc) \
assert(jc->type != JSON_T_FALSE); \
assert(jc->type != JSON_T_TRUE); \
assert(jc->type != JSON_T_NULL); \
assert(jc->type != JSON_T_STRING)
int
JSON_parser_char(JSON_parser jc, int next_char)
{
/*
After calling new_JSON_parser, call this function for each character (or
partial character) in your JSON text. It can accept UTF-8, UTF-16, or
UTF-32. It returns true if things are looking ok so far. If it rejects the
text, it returns false.
*/
int next_class, next_state;
/*
Store the current char for error handling
*/
jc->current_char = next_char;
/*
Determine the character's class.
*/
if (next_char < 0) {
jc->error = JSON_E_INVALID_CHAR;
return false;
}
if (next_char >= 128) {
next_class = C_ETC;
} else {
next_class = ascii_class[next_char];
if (next_class <= __) {
set_error(jc);
return false;
}
}
if (!add_char_to_parse_buffer(jc, next_char, next_class)) {
return false;
}
/*
Get the next state from the state transition table.
*/
next_state = state_transition_table[jc->state][next_class];
if (next_state >= 0) {
/*
Change the state.
*/
jc->state = (signed char)next_state;
} else {
/*
Or perform one of the actions.
*/
switch (next_state) {
/* Unicode character */
case UC:
if(!decode_unicode_char(jc)) {
jc->error = JSON_E_INVALID_UNICODE_SEQUENCE;
return false;
}
/* check if we need to read a second UTF-16 char */
if (jc->utf16_high_surrogate) {
jc->state = D1;
} else {
jc->state = ST;
}
break;
/* escaped char */
case EX:
jc->escaped = 1;
jc->state = ES;
break;
/* integer detected by minus */
case MX:
jc->type = JSON_T_INTEGER;
jc->state = MI;
break;
/* integer detected by zero */
case ZX:
jc->type = JSON_T_INTEGER;
jc->state = ZE;
break;
/* integer detected by 1-9 */
case IX:
jc->type = JSON_T_INTEGER;
jc->state = IT;
break;
/* floating point number detected by exponent*/
case DE:
assert_type_isnt_string_null_or_bool(jc);
jc->type = JSON_T_FLOAT;
jc->state = E1;
break;
/* floating point number detected by fraction */
case DF:
assert_type_isnt_string_null_or_bool(jc);
if (!jc->handle_floats_manually) {
/*
Some versions of strtod (which underlies sscanf) don't support converting
C-locale formated floating point values.
*/
assert(jc->parse_buffer[jc->parse_buffer_count-1] == '.');
jc->parse_buffer[jc->parse_buffer_count-1] = jc->decimal_point;
}
jc->type = JSON_T_FLOAT;
jc->state = FX;
break;
/* string begin " */
case SB:
parse_buffer_clear(jc);
assert(jc->type == JSON_T_NONE);
jc->type = JSON_T_STRING;
jc->state = ST;
break;
/* n */
case NU:
assert(jc->type == JSON_T_NONE);
jc->type = JSON_T_NULL;
jc->state = N1;
break;
/* f */
case FA:
assert(jc->type == JSON_T_NONE);
jc->type = JSON_T_FALSE;
jc->state = F1;
break;
/* t */
case TR:
assert(jc->type == JSON_T_NONE);
jc->type = JSON_T_TRUE;
jc->state = T1;
break;
/* closing comment */
case CE:
jc->comment = 0;
assert(jc->parse_buffer_count == 0);
assert(jc->type == JSON_T_NONE);
jc->state = jc->before_comment_state;
break;
/* opening comment */
case CB:
if (!jc->allow_comments) {
return false;
}
parse_buffer_pop_back_char(jc);
if (!parse_parse_buffer(jc)) {
return false;
}
assert(jc->parse_buffer_count == 0);
assert(jc->type != JSON_T_STRING);
switch (jc->stack[jc->top]) {
case MODE_ARRAY:
case MODE_OBJECT:
switch(jc->state) {
case VA:
case AR:
jc->before_comment_state = jc->state;
break;
default:
jc->before_comment_state = OK;
break;
}
break;
default:
jc->before_comment_state = jc->state;
break;
}
jc->type = JSON_T_NONE;
jc->state = C1;
jc->comment = 1;
break;
/* empty } */
case -9:
parse_buffer_clear(jc);
if (jc->callback && !(*jc->callback)(jc->ctx, JSON_T_OBJECT_END, NULL)) {
return false;
}
if (!pop(jc, MODE_KEY)) {
return false;
}
jc->state = OK;
break;
/* } */ case -8:
parse_buffer_pop_back_char(jc);
if (!parse_parse_buffer(jc)) {
return false;
}
if (jc->callback && !(*jc->callback)(jc->ctx, JSON_T_OBJECT_END, NULL)) {
return false;
}
if (!pop(jc, MODE_OBJECT)) {
jc->error = JSON_E_UNBALANCED_COLLECTION;
return false;
}
jc->type = JSON_T_NONE;
jc->state = OK;
break;
/* ] */ case -7:
parse_buffer_pop_back_char(jc);
if (!parse_parse_buffer(jc)) {
return false;
}
if (jc->callback && !(*jc->callback)(jc->ctx, JSON_T_ARRAY_END, NULL)) {
return false;
}
if (!pop(jc, MODE_ARRAY)) {
jc->error = JSON_E_UNBALANCED_COLLECTION;
return false;
}
jc->type = JSON_T_NONE;
jc->state = OK;
break;
/* { */ case -6:
parse_buffer_pop_back_char(jc);
if (jc->callback && !(*jc->callback)(jc->ctx, JSON_T_OBJECT_BEGIN, NULL)) {
return false;
}
if (!push(jc, MODE_KEY)) {
return false;
}
assert(jc->type == JSON_T_NONE);
jc->state = OB;
break;
/* [ */ case -5:
parse_buffer_pop_back_char(jc);
if (jc->callback && !(*jc->callback)(jc->ctx, JSON_T_ARRAY_BEGIN, NULL)) {
return false;
}
if (!push(jc, MODE_ARRAY)) {
return false;
}
assert(jc->type == JSON_T_NONE);
jc->state = AR;
break;
/* string end " */ case -4:
parse_buffer_pop_back_char(jc);
switch (jc->stack[jc->top]) {
case MODE_KEY:
assert(jc->type == JSON_T_STRING);
jc->type = JSON_T_NONE;
jc->state = CO;
if (jc->callback) {
JSON_value value;
value.vu.str.value = jc->parse_buffer;
value.vu.str.length = jc->parse_buffer_count;
if (!(*jc->callback)(jc->ctx, JSON_T_KEY, &value)) {
return false;
}
}
parse_buffer_clear(jc);
break;
case MODE_ARRAY:
case MODE_OBJECT:
assert(jc->type == JSON_T_STRING);
if (!parse_parse_buffer(jc)) {
return false;
}
jc->type = JSON_T_NONE;
jc->state = OK;
break;
default:
return false;
}
break;
/* , */ case -3:
parse_buffer_pop_back_char(jc);
if (!parse_parse_buffer(jc)) {
return false;
}
switch (jc->stack[jc->top]) {
case MODE_OBJECT:
/*
A comma causes a flip from object mode to key mode.
*/
if (!pop(jc, MODE_OBJECT) || !push(jc, MODE_KEY)) {
return false;
}
assert(jc->type != JSON_T_STRING);
jc->type = JSON_T_NONE;
jc->state = KE;
break;
case MODE_ARRAY:
assert(jc->type != JSON_T_STRING);
jc->type = JSON_T_NONE;
jc->state = VA;
break;
default:
return false;
}
break;
/* : */ case -2:
/*
A colon causes a flip from key mode to object mode.
*/
parse_buffer_pop_back_char(jc);
if (!pop(jc, MODE_KEY) || !push(jc, MODE_OBJECT)) {
return false;
}
assert(jc->type == JSON_T_NONE);
jc->state = VA;
break;
/*
Bad action.
*/
default:
set_error(jc);
return false;
}
}
return true;
}
int
JSON_parser_done(JSON_parser jc)
{
if ((jc->state == OK || jc->state == GO) && pop(jc, MODE_DONE))
{
return true;
}
jc->error = JSON_E_UNBALANCED_COLLECTION;
return false;
}
int JSON_parser_is_legal_white_space_string(const char* s)
{
int c, char_class;
if (s == NULL) {
return false;
}
for (; *s; ++s) {
c = *s;
if (c < 0 || c >= 128) {
return false;
}
char_class = ascii_class[c];
if (char_class != C_SPACE && char_class != C_WHITE) {
return false;
}
}
return true;
}
int JSON_parser_get_last_error(JSON_parser jc)
{
return jc->error;
}
void init_JSON_config(JSON_config* config)
{
if (config) {
memset(config, 0, sizeof(*config));
config->depth = JSON_PARSER_STACK_SIZE - 1;
config->malloc = malloc;
config->free = free;
}
}
Raw
JSON_parser.h
/* See JSON_parser.c for copyright information and licensing. */
#ifndef JSON_PARSER_H
#define JSON_PARSER_H
/* JSON_parser.h */
#include <stddef.h>
/* Windows DLL stuff */
#ifdef JSON_PARSER_DLL
# ifdef _MSC_VER
# ifdef JSON_PARSER_DLL_EXPORTS
# define JSON_PARSER_DLL_API __declspec(dllexport)
# else
# define JSON_PARSER_DLL_API __declspec(dllimport)
# endif
# else
# define JSON_PARSER_DLL_API
# endif
#else
# define JSON_PARSER_DLL_API
#endif
/* Determine the integer type use to parse non-floating point numbers */
#if defined(_MSC_VER)
typedef __int64 JSON_int_t;
#define JSON_PARSER_INTEGER_SSCANF_TOKEN "%lld"
#define JSON_PARSER_INTEGER_SPRINTF_TOKEN "%lld"
#elif __STDC_VERSION__ >= 199901L || HAVE_LONG_LONG == 1
typedef long long JSON_int_t;
#define JSON_PARSER_INTEGER_SSCANF_TOKEN "%lld"
#define JSON_PARSER_INTEGER_SPRINTF_TOKEN "%lld"
#else
typedef long JSON_int_t;
#define JSON_PARSER_INTEGER_SSCANF_TOKEN "%ld"
#define JSON_PARSER_INTEGER_SPRINTF_TOKEN "%ld"
#endif
#ifdef __cplusplus
extern "C" {
#endif
typedef enum
{
JSON_E_NONE = 0,
JSON_E_INVALID_CHAR,
JSON_E_INVALID_KEYWORD,
JSON_E_INVALID_ESCAPE_SEQUENCE,
JSON_E_INVALID_UNICODE_SEQUENCE,
JSON_E_INVALID_NUMBER,
JSON_E_NESTING_DEPTH_REACHED,
JSON_E_UNBALANCED_COLLECTION,
JSON_E_EXPECTED_KEY,
JSON_E_EXPECTED_COLON,
JSON_E_OUT_OF_MEMORY
} JSON_error;
typedef enum
{
JSON_T_NONE = 0,
JSON_T_ARRAY_BEGIN,
JSON_T_ARRAY_END,
JSON_T_OBJECT_BEGIN,
JSON_T_OBJECT_END,
JSON_T_INTEGER,
JSON_T_FLOAT,
JSON_T_NULL,
JSON_T_TRUE,
JSON_T_FALSE,
JSON_T_STRING,
JSON_T_KEY,
JSON_T_MAX
} JSON_type;
typedef struct JSON_value_struct {
union {
JSON_int_t integer_value;
double float_value;
struct {
const char* value;
size_t length;
} str;
} vu;
} JSON_value;
typedef struct JSON_parser_struct* JSON_parser;
/*! \brief JSON parser callback
\param ctx The pointer passed to new_JSON_parser.
\param type An element of JSON_type but not JSON_T_NONE.
\param value A representation of the parsed value. This parameter is NULL for
JSON_T_ARRAY_BEGIN, JSON_T_ARRAY_END, JSON_T_OBJECT_BEGIN, JSON_T_OBJECT_END,
JSON_T_NULL, JSON_T_TRUE, and JSON_T_FALSE. String values are always returned
as zero-terminated C strings.
\return Non-zero if parsing should continue, else zero.
*/
typedef int (*JSON_parser_callback)(void* ctx, int type, const struct JSON_value_struct* value);
/**
A typedef for allocator functions semantically compatible with malloc().
*/
typedef void* (*JSON_malloc_t)(size_t n);
/**
A typedef for deallocator functions semantically compatible with free().
*/
typedef void (*JSON_free_t)(void* mem);
/*! \brief The structure used to configure a JSON parser object
*/
typedef struct {
/** Pointer to a callback, called when the parser has something to tell
the user. This parameter may be NULL. In this case the input is
merely checked for validity.
*/
JSON_parser_callback callback;
/**
Callback context - client-specified data to pass to the
callback function. This parameter may be NULL.
*/
void* callback_ctx;
/** Specifies the levels of nested JSON to allow. Negative numbers yield unlimited nesting.
If negative, the parser can parse arbitrary levels of JSON, otherwise
the depth is the limit.
*/
int depth;
/**
To allow C style comments in JSON, set to non-zero.
*/
int allow_comments;
/**
To decode floating point numbers manually set this parameter to
non-zero.
*/
int handle_floats_manually;
/**
The memory allocation routine, which must be semantically
compatible with malloc(3). If set to NULL, malloc(3) is used.
If this is set to a non-NULL value then the 'free' member MUST be
set to the proper deallocation counterpart for this function.
Failure to do so results in undefined behaviour at deallocation
time.
*/
JSON_malloc_t malloc;
/**
The memory deallocation routine, which must be semantically
compatible with free(3). If set to NULL, free(3) is used.
If this is set to a non-NULL value then the 'alloc' member MUST be
set to the proper allocation counterpart for this function.
Failure to do so results in undefined behaviour at deallocation
time.
*/
JSON_free_t free;
} JSON_config;
/*! \brief Initializes the JSON parser configuration structure to default values.
The default configuration is
- 127 levels of nested JSON (depends on JSON_PARSER_STACK_SIZE, see json_parser.c)
- no parsing, just checking for JSON syntax
- no comments
- Uses realloc() for memory de/allocation.
\param config. Used to configure the parser.
*/
JSON_PARSER_DLL_API void init_JSON_config(JSON_config * config);
/*! \brief Create a JSON parser object
\param config. Used to configure the parser. Set to NULL to use
the default configuration. See init_JSON_config. Its contents are
copied by this function, so it need not outlive the returned
object.
\return The parser object, which is owned by the caller and must eventually
be freed by calling delete_JSON_parser().
*/
JSON_PARSER_DLL_API JSON_parser new_JSON_parser(JSON_config const* config);
/*! \brief Destroy a previously created JSON parser object. */
JSON_PARSER_DLL_API void delete_JSON_parser(JSON_parser jc);
/*! \brief Parse a character.
\return Non-zero, if all characters passed to this function are part of are valid JSON.
*/
JSON_PARSER_DLL_API int JSON_parser_char(JSON_parser jc, int next_char);
/*! \brief Finalize parsing.
Call this method once after all input characters have been consumed.
\return Non-zero, if all parsed characters are valid JSON, zero otherwise.
*/
JSON_PARSER_DLL_API int JSON_parser_done(JSON_parser jc);
/*! \brief Determine if a given string is valid JSON white space
\return Non-zero if the string is valid, zero otherwise.
*/
JSON_PARSER_DLL_API int JSON_parser_is_legal_white_space_string(const char* s);
/*! \brief Gets the last error that occurred during the use of JSON_parser.
\return A value from the JSON_error enum.
*/
JSON_PARSER_DLL_API int JSON_parser_get_last_error(JSON_parser jc);
/*! \brief Re-sets the parser to prepare it for another parse run.
\return True (non-zero) on success, 0 on error (e.g. !jc).
*/
JSON_PARSER_DLL_API int JSON_parser_reset(JSON_parser jc);
#ifdef __cplusplus
}
#endif
#endif /* JSON_PARSER_H */
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