ObjFW  Artifact [c7c766a996]

Artifact c7c766a99693f9573b492cf73d1fb1fb0bd79368b2bb95a7ba78c06065c57c1a:

• File src/OFString+JSONValue.m — part of check-in [3d16a30f41] at 2013-06-22 12:12:36 on branch trunk — Rework exceptions.

  This mostly removes the argument for the class in which the exception
  occurred. As backtraces were recently added for all platforms, the
  passed class does not give any extra information on where the exception
  occurred anymore.

  This also removes a few other arguments which were not too helpful. In
  the past, the idea was to pass as many arguments as possible so that it
  is easier to find the origin of the exception. However, as backtraces
  are a much better way to find the origin, those are not useful anymore
  and just make the exception more cumbersome to use. The rule is now to
  only pass arguments that might help in recovering from the exception or
  provide information that is otherwise not easily accessible. (user: js, size: 13069) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013
 *   Jonathan Schleifer <js@webkeks.org>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>

#include <math.h>

#include <assert.h>

#import "OFString+JSONValue.h"
#import "OFArray.h"
#import "OFDictionary.h"
#import "OFNumber.h"
#import "OFNull.h"

#import "OFInvalidJSONException.h"

#import "macros.h"

int _OFString_JSONValue_reference;

static id nextObject(const char *restrict *, const char*,
    size_t *restrict line, size_t depth, size_t depthLimit);

static void
skipWhitespaces(const char *restrict *pointer, const char *stop,
    size_t *restrict line)
{
	while (*pointer < stop && (**pointer == ' ' || **pointer == '\t' ||
	    **pointer == '\r' || **pointer == '\n')) {
		if (**pointer == '\n')
			(*line)++;

		(*pointer)++;
	}
}

static void
skipComment(const char *restrict *pointer, const char *stop,
    size_t *restrict line)
{
	if (**pointer != '/')
		return;

	if (*pointer + 1 >= stop)
		return;

	(*pointer)++;

	if (**pointer == '*') {
		bool lastIsAsterisk = false;

		(*pointer)++;

		while (*pointer < stop) {
			if (lastIsAsterisk && **pointer == '/') {
				(*pointer)++;
				return;
			}

			lastIsAsterisk = (**pointer == '*');

			if (**pointer == '\n')
				(*line)++;

			(*pointer)++;
		}
	} else if (**pointer == '/') {
		(*pointer)++;

		while (*pointer < stop) {
			if (**pointer == '\r' || **pointer == '\n') {
				(*pointer)++;
				(*line)++;
				return;
			}

			(*pointer)++;
		}
	} else
		(*pointer)--;
}

static void
skipWhitespacesAndComments(const char *restrict *pointer, const char *stop,
    size_t *restrict line)
{
	const char *old = NULL;

	while (old != *pointer) {
		old = *pointer;

		skipWhitespaces(pointer, stop, line);
		skipComment(pointer, stop, line);
	}
}

static inline of_char16_t
parseUnicodeEscape(const char *pointer, const char *stop)
{
	of_char16_t ret = 0;
	char i;

	if (pointer + 5 >= stop)
		return 0xFFFF;

	if (pointer[0] != '\\' || pointer[1] != 'u')
		return 0xFFFF;

	for (i = 0; i < 4; i++) {
		char c = pointer[i + 2];
		ret <<= 4;

		if (c >= '0' && c <= '9')
			ret |= c - '0';
		else if (c >= 'a' && c <= 'f')
			ret |= c + 10 - 'a';
		else if (c >= 'A' && c <= 'F')
			ret |= c + 10 - 'A';
		else
			return 0xFFFF;
	}

	if (ret == 0)
		return 0xFFFF;

	return ret;
}

static inline OFString*
parseString(const char *restrict *pointer, const char *stop,
    size_t *restrict line)
{
	char *buffer;
	size_t i = 0;
	char delimiter = **pointer;

	if (++(*pointer) + 1 >= stop)
		return nil;

	if ((buffer = malloc(stop - *pointer)) == NULL)
		return nil;

	while (*pointer < stop) {
		/* Parse escape codes */
		if (**pointer == '\\') {
			if (++(*pointer) >= stop) {
				free(buffer);
				return nil;
			}

			switch (**pointer) {
			case '"':
			case '\\':
			case '/':
				buffer[i++] = **pointer;
				(*pointer)++;
				break;
			case 'b':
				buffer[i++] = '\b';
				(*pointer)++;
				break;
			case 'f':
				buffer[i++] = '\f';
				(*pointer)++;
				break;
			case 'n':
				buffer[i++] = '\n';
				(*pointer)++;
				break;
			case 'r':
				buffer[i++] = '\r';
				(*pointer)++;
				break;
			case 't':
				buffer[i++] = '\t';
				(*pointer)++;
				break;
			/* Parse unicode escape sequence */
			case 'u':;
				of_char16_t c1, c2;
				of_unichar_t c;
				size_t l;

				c1 = parseUnicodeEscape(*pointer - 1, stop);
				if (c1 == 0xFFFF) {
					free(buffer);
					return nil;
				}

				/* Low surrogate */
				if ((c1 & 0xFC00) == 0xDC00) {
					free(buffer);
					return nil;
				}

				/* Normal character */
				if ((c1 & 0xFC00) != 0xD800) {
					l = of_string_utf8_encode(c1,
					    buffer + i);
					if (l == 0) {
						free(buffer);
						return nil;
					}

					i += l;
					*pointer += 5;

					break;
				}

				/*
				 * If we are still here, we only got one UTF-16
				 * surrogate and now need to get the other one
				 * in order to produce UTF-8 and not CESU-8.
				 */
				c2 = parseUnicodeEscape(*pointer + 5, stop);
				if (c2 == 0xFFFF) {
					free(buffer);
					return nil;
				}

				c = (((c1 & 0x3FF) << 10) |
				    (c2 & 0x3FF)) + 0x10000;

				l = of_string_utf8_encode(c, buffer + i);
				if (l == 0) {
					free(buffer);
					return nil;
				}

				i += l;
				*pointer += 11;

				break;
			case '\r':
				(*pointer)++;

				if (*pointer < stop && **pointer == '\n') {
					(*pointer)++;
					(*line)++;
				}

				break;
			case '\n':
				(*pointer)++;
				(*line)++;
				break;
			default:
				free(buffer);
				return nil;
			}
		/* End of string found */
		} else if (**pointer == delimiter) {
			OFString *ret;

			@try {
				ret = [OFString stringWithUTF8String: buffer
							      length: i];
			} @finally {
				free(buffer);
			}

			(*pointer)++;

			return ret;
		/* Newlines in strings are disallowed */
		} else if (**pointer == '\n' || **pointer == '\r') {
			(*line)++;
			free(buffer);
			return nil;
		} else {
			buffer[i++] = **pointer;
			(*pointer)++;
		}
	}

	free(buffer);
	return nil;
}

static inline OFString*
parseIdentifier(const char *restrict *pointer, const char *stop)
{
	char *buffer;
	size_t i = 0;

	if ((buffer = malloc(stop - *pointer)) == NULL)
		return nil;

	while (*pointer < stop) {
		if ((**pointer >= 'a' && **pointer <= 'z') ||
		    (**pointer >= 'A' && **pointer <= 'Z') ||
		    (**pointer >= '0' && **pointer <= '9') ||
		    **pointer == '_' || **pointer == '$' ||
		    (**pointer & 0x80)) {
			buffer[i++] = **pointer;
			(*pointer)++;
		} else if (**pointer == '\\') {
			of_char16_t c1, c2;
			of_unichar_t c;
			size_t l;

			if (++(*pointer) >= stop || **pointer != 'u') {
				free(buffer);
				return nil;
			}

			c1 = parseUnicodeEscape(*pointer - 1, stop);
			if (c1 == 0xFFFF) {
				free(buffer);
				return nil;
			}

			/* Low surrogate */
			if ((c1 & 0xFC00) == 0xDC00) {
				free(buffer);
				return nil;
			}

			/* Normal character */
			if ((c1 & 0xFC00) != 0xD800) {
				l = of_string_utf8_encode(c1, buffer + i);
				if (l == 0) {
					free(buffer);
					return nil;
				}

				i += l;
				*pointer += 5;

				continue;
			}

			/*
			 * If we are still here, we only got one UTF-16
			 * surrogate and now need to get the other one in order
			 * to produce UTF-8 and not CESU-8.
			 */
			c2 = parseUnicodeEscape(*pointer + 5, stop);
			if (c2 == 0xFFFF) {
				free(buffer);
				return nil;
			}

			c = (((c1 & 0x3FF) << 10) | (c2 & 0x3FF)) + 0x10000;

			l = of_string_utf8_encode(c, buffer + i);
			if (l == 0) {
				free(buffer);
				return nil;
			}

			i += l;
			*pointer += 11;
		} else {
			OFString *ret;

			if (i == 0 || (buffer[0] >= '0' && buffer[0] <= '9')) {
				free(buffer);
				return nil;
			}

			@try {
				ret = [OFString stringWithUTF8String: buffer
							      length: i];
			} @finally {
				free(buffer);
			}

			return ret;
		}
	}

	/*
	 * It is never possible to end with an identifier, thus we should never
	 * reach stop.
	 */
	return nil;
}

static inline OFMutableArray*
parseArray(const char *restrict *pointer, const char *stop,
    size_t *restrict line, size_t depth, size_t depthLimit)
{
	OFMutableArray *array = [OFMutableArray array];

	if (++(*pointer) >= stop)
		return nil;

	if (++depth > depthLimit)
		return nil;

	while (**pointer != ']') {
		id object;

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer >= stop)
			return nil;

		if (**pointer == ']')
			break;

		if (**pointer == ',') {
			(*pointer)++;
			skipWhitespacesAndComments(pointer, stop, line);

			if (*pointer >= stop || **pointer != ']')
				return nil;

			break;
		}

		object = nextObject(pointer, stop, line, depth, depthLimit);
		if (object == nil)
			return nil;

		[array addObject: object];

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer >= stop)
			return nil;

		if (**pointer == ',') {
			(*pointer)++;
			skipWhitespacesAndComments(pointer, stop, line);

			if (*pointer >= stop)
				return nil;
		} else if (**pointer != ']')
			return nil;
	}

	(*pointer)++;

	return array;
}

static inline OFMutableDictionary*
parseDictionary(const char *restrict *pointer, const char *stop,
    size_t *restrict line, size_t depth, size_t depthLimit)
{
	OFMutableDictionary *dictionary = [OFMutableDictionary dictionary];

	if (++(*pointer) >= stop)
		return nil;

	if (++depth > depthLimit)
		return nil;

	while (**pointer != '}') {
		id key, object;

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer >= stop)
			return nil;

		if (**pointer == '}')
			break;

		if (**pointer == ',') {
			(*pointer)++;
			skipWhitespacesAndComments(pointer, stop, line);

			if (*pointer >= stop || **pointer != '}')
				return nil;

			break;
		}

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer + 1 >= stop)
			return nil;

		if ((**pointer >= 'a' && **pointer <= 'z') ||
		    (**pointer >= 'A' && **pointer <= 'Z') ||
		    **pointer == '_' || **pointer == '$' || **pointer == '\\')
			key = parseIdentifier(pointer, stop);
		else
			key = nextObject(pointer, stop, line,
			    depth, depthLimit);

		if (key == nil)
			return nil;

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer + 1 >= stop || **pointer != ':')
			return nil;

		(*pointer)++;

		object = nextObject(pointer, stop, line, depth, depthLimit);
		if (object == nil)
			return nil;

		[dictionary setObject: object
			       forKey: key];

		skipWhitespacesAndComments(pointer, stop, line);
		if (*pointer >= stop)
			return nil;

		if (**pointer == ',') {
			(*pointer)++;
			skipWhitespacesAndComments(pointer, stop, line);

			if (*pointer >= stop)
				return nil;
		} else if (**pointer != '}')
			return nil;
	}

	(*pointer)++;

	return dictionary;
}

static inline OFNumber*
parseNumber(const char *restrict *pointer, const char *stop,
    size_t *restrict line)
{
	bool isHex = (*pointer + 1 < stop && (*pointer)[1] == 'x');
	bool hasDecimal = false;
	size_t i;
	OFString *string;
	OFNumber *number;

	for (i = 0; *pointer + i < stop; i++) {
		if ((*pointer)[i] == '.')
			hasDecimal = true;

		if ((*pointer)[i] == ' ' || (*pointer)[i] == '\t' ||
		    (*pointer)[i] == '\r' || (*pointer)[i] == '\n' ||
		    (*pointer)[i] == ',' || (*pointer)[i] == ']' ||
		    (*pointer)[i] == '}') {
			if ((*pointer)[i] == '\n')
				(*line)++;

			break;
		}
	}

	string = [[OFString alloc] initWithUTF8String: *pointer
					       length: i];
	*pointer += i;

	@try {
		if (hasDecimal)
			number = [OFNumber numberWithDouble:
			    [string doubleValue]];
		else if (isHex)
			number = [OFNumber numberWithIntMax:
			    [string hexadecimalValue]];
		else if ([string isEqual: @"Infinity"])
			number = [OFNumber numberWithDouble: INFINITY];
		else if ([string isEqual: @"-Infinity"])
			number = [OFNumber numberWithDouble: -INFINITY];
		else
			number = [OFNumber numberWithIntMax:
			    [string decimalValue]];
	} @finally {
		[string release];
	}

	return number;
}

static id
nextObject(const char *restrict *pointer, const char *stop,
    size_t *restrict line, size_t depth, size_t depthLimit)
{
	skipWhitespacesAndComments(pointer, stop, line);

	if (*pointer >= stop)
		return nil;

	switch (**pointer) {
	case '"':
	case '\'':
		return parseString(pointer, stop, line);
	case '[':
		return parseArray(pointer, stop, line, depth, depthLimit);
	case '{':
		return parseDictionary(pointer, stop, line, depth, depthLimit);
	case 't':
		if (*pointer + 3 >= stop)
			return nil;

		if (memcmp(*pointer, "true", 4))
			return nil;

		(*pointer) += 4;

		return [OFNumber numberWithBool: true];
	case 'f':
		if (*pointer + 4 >= stop)
			return nil;

		if (memcmp(*pointer, "false", 5))
			return nil;

		(*pointer) += 5;

		return [OFNumber numberWithBool: false];
	case 'n':
		if (*pointer + 3 >= stop)
			return nil;

		if (memcmp(*pointer, "null", 4))
			return nil;

		(*pointer) += 4;

		return [OFNull null];
	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	case '+':
	case '-':
	case '.':
	case 'I':
		return parseNumber(pointer, stop, line);
	default:
		return nil;
	}
}

@implementation OFString (JSONValue)
- (id)JSONValue
{
	return [self JSONValueWithDepthLimit: 32];
}

- (id)JSONValueWithDepthLimit: (size_t)depthLimit
{
	const char *pointer = [self UTF8String];
	const char *stop = pointer + [self UTF8StringLength];
	id object;
	size_t line = 1;

	object = nextObject(&pointer, stop, &line, 0, depthLimit);
	skipWhitespacesAndComments(&pointer, stop, &line);

	if (pointer < stop || object == nil)
		@throw [OFInvalidJSONException exceptionWithString: self
							      line: line];

	return object;
}
@end