ObjFW  Artifact [5784ae8273]

Artifact 5784ae82732f2cac31c27708385da517d170554a9afdab1112f9c66dd46f2df7:

• File src/OFString+XMLUnescaping.m — part of check-in [e1e7ffa903] at 2011-09-22 23:25:42 on branch trunk — Exceptions are now autoreleased.

  This is safe as an "exception loop" can't happen, since if allocating
  an exception fails, it throws an OFAllocFailedException which is
  preallocated and can always be thrown.

  So, the worst case would be that an autorelease of an exception fails,
  triggering an OFOutOfMemoryException for which there is no memory,
  resulting in an OFAllocFailedException to be thrown. (user: js, size: 6717) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011
 *   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 <string.h>

#import "OFString.h"
#import "OFAutoreleasePool.h"

#import "OFInvalidEncodingException.h"

#import "macros.h"

int _OFString_XMLUnescaping_reference;

static OF_INLINE OFString*
parse_numeric_entity(const char *entity, size_t length)
{
	of_unichar_t c;
	size_t i;
	char buffer[5];

	if (length == 1 || *entity != '#')
		return nil;

	c = 0;
	entity++;
	length--;

	if (entity[0] == 'x') {
		if (length == 1)
			return nil;

		entity++;
		length--;

		for (i = 0; i < length; i++) {
			if (entity[i] >= '0' && entity[i] <= '9')
				c = (c << 4) + (entity[i] - '0');
			else if (entity[i] >= 'A' && entity[i] <= 'F')
				c = (c << 4) + (entity[i] - 'A' + 10);
			else if (entity[i] >= 'a' && entity[i] <= 'f')
				c = (c << 4) + (entity[i] - 'a' + 10);
			else
				return nil;
		}
	} else {
		for (i = 0; i < length; i++) {
			if (entity[i] >= '0' && entity[i] <= '9')
				c = (c * 10) + (entity[i] - '0');
			else
				return nil;
		}
	}

	if ((i = of_string_unicode_to_utf8(c, buffer)) == 0)
		return nil;
	buffer[i] = 0;

	return [OFString stringWithUTF8String: buffer
				       length: i];
}

@implementation OFString (XMLUnescaping)
- (OFString*)stringByXMLUnescaping
{
	return [self stringByXMLUnescapingWithDelegate: nil];
}

- (OFString*)stringByXMLUnescapingWithDelegate:
    (id <OFStringXMLUnescapingDelegate>)delegate
{
	const char *string;
	size_t i, last, length;
	BOOL inEntity;
	OFMutableString *ret;

	string = [self UTF8String];
	length = [self UTF8StringLength];

	ret = [OFMutableString string];

	last = 0;
	inEntity = NO;

	for (i = 0; i < length; i++) {
		if (!inEntity && string[i] == '&') {
			[ret appendUTF8String: string + last
				   withLength: i - last];

			last = i + 1;
			inEntity = YES;
		} else if (inEntity && string[i] == ';') {
			const char *entity = string + last;
			size_t entityLength = i - last;

			if (entityLength == 2 && !memcmp(entity, "lt", 2))
				[ret appendCString: "<"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 2 && !memcmp(entity, "gt", 2))
				[ret appendCString: ">"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 4 &&
			    !memcmp(entity, "quot", 4))
				[ret appendCString: "\""
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 4 &&
			    !memcmp(entity, "apos", 4))
				[ret appendCString: "'"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 3 && !memcmp(entity, "amp", 3))
				[ret appendCString: "&"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entity[0] == '#') {
				OFAutoreleasePool *pool;
				OFString *tmp;

				pool = [[OFAutoreleasePool alloc] init];
				tmp = parse_numeric_entity(entity,
				    entityLength);

				if (tmp == nil)
					@throw [OFInvalidEncodingException
					    exceptionWithClass: isa];

				[ret appendString: tmp];
				[pool release];
			} else if (delegate != nil) {
				OFAutoreleasePool *pool;
				OFString *n, *tmp;

				pool = [[OFAutoreleasePool alloc] init];

				n = [OFString
				    stringWithUTF8String: entity
						  length: entityLength];
				tmp =	  [delegate string: self
				containsUnknownEntityNamed: n];

				if (tmp == nil)
					@throw [OFInvalidEncodingException
					    exceptionWithClass: isa];

				[ret appendString: tmp];
				[pool release];
			} else
				@throw [OFInvalidEncodingException
				    exceptionWithClass: isa];

			last = i + 1;
			inEntity = NO;
		}
	}

	if (inEntity)
		@throw [OFInvalidEncodingException exceptionWithClass: isa];

	[ret appendUTF8String: string + last
		   withLength: i - last];

	[ret makeImmutable];

	return ret;
}

#ifdef OF_HAVE_BLOCKS
- (OFString*)stringByXMLUnescapingWithBlock:
    (of_string_xml_unescaping_block_t)block
{
	const char *string;
	size_t i, last, length;
	BOOL inEntity;
	OFMutableString *ret;

	string = [self UTF8String];
	length = [self UTF8StringLength];

	ret = [OFMutableString string];

	last = 0;
	inEntity = NO;

	for (i = 0; i < length; i++) {
		if (!inEntity && string[i] == '&') {
			[ret appendUTF8String: string + last
				   withLength: i - last];

			last = i + 1;
			inEntity = YES;
		} else if (inEntity && string[i] == ';') {
			const char *entity = string + last;
			size_t entityLength = i - last;

			if (entityLength == 2 && !memcmp(entity, "lt", 2))
				[ret appendCString: "<"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 2 && !memcmp(entity, "gt", 2))
				[ret appendCString: ">"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 4 &&
			    !memcmp(entity, "quot", 4))
				[ret appendCString: "\""
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 4 &&
			    !memcmp(entity, "apos", 4))
				[ret appendCString: "'"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entityLength == 3 && !memcmp(entity, "amp", 3))
				[ret appendCString: "&"
				      withEncoding: OF_STRING_ENCODING_ASCII
					    length: 1];
			else if (entity[0] == '#') {
				OFAutoreleasePool *pool;
				OFString *tmp;

				pool = [[OFAutoreleasePool alloc] init];
				tmp = parse_numeric_entity(entity,
				    entityLength);

				if (tmp == nil)
					@throw [OFInvalidEncodingException
					    exceptionWithClass: isa];

				[ret appendString: tmp];
				[pool release];
			} else {
				OFAutoreleasePool *pool;
				OFString *entityString, *tmp;

				pool = [[OFAutoreleasePool alloc] init];

				entityString = [OFString
				    stringWithUTF8String: entity
						  length: entityLength];
				tmp = block(self, entityString);

				if (tmp == nil)
					@throw [OFInvalidEncodingException
					    exceptionWithClass: isa];

				[ret appendString: tmp];
				[pool release];
			}

			last = i + 1;
			inEntity = NO;
		}
	}

	if (inEntity)
		@throw [OFInvalidEncodingException exceptionWithClass: isa];

	[ret appendUTF8String: string + last
		   withLength: i - last];

	[ret makeImmutable];

	return ret;
}
#endif
@end