ObjFW  Artifact [dff3658c98]

Artifact dff3658c98a368f971743cedc4763cff523018fc8802d5e94a5e31e32e983880:

• File src/OFStream.m — part of check-in [fc0b2500b9] at 2009-12-03 18:50:41 on branch trunk — Make OFStream caching invisible to the programmer. (user: js, size: 4966) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008 - 2009
 *   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 included in
 * the packaging of this file.
 */

#include "config.h"

#include <string.h>
#include <unistd.h>

#import "OFStream.h"
#import "OFExceptions.h"
#import "OFMacros.h"

#ifdef _WIN32
#include <windows.h>
#endif

static int pagesize = 0;

@implementation OFStream
- init
{
	self = [super init];

	if (isa == [OFStream class])
		@throw [OFNotImplementedException newWithClass: isa
						      selector: _cmd];

	cache = NULL;

#ifndef _WIN32
	if (pagesize == 0)
		if ((pagesize = sysconf(_SC_PAGESIZE)) == -1)
			pagesize = 4096;
#else
	if (pagesize == 0) {
		SYSTEM_INFO si;
		GetSystemInfo(&si);
		pagesize = si.dwPageSize - 1;
	}
#endif

	return self;
}

- (BOOL)atEndOfStream
{
	if (cache != NULL)
		return NO;

	return [self atEndOfStreamWithoutCache];
}

- (BOOL)atEndOfStreamWithoutCache
{
	@throw [OFNotImplementedException newWithClass: isa
					      selector: _cmd];
}

- (size_t)readNBytes: (size_t)size
	  intoBuffer: (char*)buf
{
	if (cache == NULL)
		return [self readNBytesWithoutCache: size
					 intoBuffer: buf];

	if (size >= cache_len) {
		size_t ret = cache_len;
		memcpy(buf, cache, cache_len);

		[self freeMemory: cache];
		cache = NULL;
		cache_len = 0;

		return ret;
	} else {
		char *tmp = [self allocMemoryWithSize: cache_len - size];
		memcpy(tmp, cache + size, cache_len - size);

		memcpy(buf, cache, size);

		[self freeMemory: cache];
		cache = tmp;
		cache_len -= size;

		return size;
	}
}

- (size_t)readNBytesWithoutCache: (size_t)size
		      intoBuffer: (char*)buf
{
	@throw [OFNotImplementedException newWithClass: isa
					      selector: _cmd];
}

- (OFString*)readLine
{
	return [self readLineWithEncoding: OF_STRING_ENCODING_UTF_8];
}

- (OFString*)readLineWithEncoding: (enum of_string_encoding)encoding
{
	size_t i, len, ret_len;
	char *ret_c, *tmp, *tmp2;
	OFString *ret;

	/* Look if there's a line or \0 in our cache */
	if (cache != NULL) {
		for (i = 0; i < cache_len; i++) {
			if (OF_UNLIKELY(cache[i] == '\n' ||
			    cache[i] == '\0')) {
				ret = [OFString stringWithCString: cache
							 encoding: encoding
							   length: i];

				tmp = [self allocMemoryWithSize: cache_len -
								 i - 1];
				memcpy(tmp, cache + i + 1, cache_len - i - 1);

				[self freeMemory: cache];
				cache = tmp;
				cache_len -= i + 1;

				return ret;
			}
		}
	}

	/* Read until we get a newline or \0 */
	tmp = [self allocMemoryWithSize: pagesize];

	for (;;) {
		if ([self atEndOfStreamWithoutCache]) {
			[self freeMemory: tmp];

			if (cache == NULL)
				return nil;

			ret = [OFString stringWithCString: cache
						 encoding: encoding
						   length: cache_len];

			[self freeMemory: cache];
			cache = NULL;
			cache_len = 0;

			return ret;
		}

		@try {
			len = [self readNBytesWithoutCache: pagesize
						intoBuffer: tmp];
		} @catch (OFException *e) {
			[self freeMemory: tmp];
			@throw e;
		}

		/* Look if there's a newline or \0 */
		for (i = 0; i < len; i++) {
			if (OF_UNLIKELY(tmp[i] == '\n' || tmp[i] == '\0')) {
				ret_len = cache_len + i;
				@try {
					ret_c = [self
					    allocMemoryWithSize: ret_len];
				} @catch (OFException *e) {
					[self freeMemory: tmp];
					@throw e;
				}
				if (cache != NULL)
					memcpy(ret_c, cache, cache_len);
				memcpy(ret_c + cache_len, tmp, i);

				if (i < len) {
					@try {
						tmp2 = [self
						    allocMemoryWithSize: len -
									 i - 1];
					} @catch (OFException *e) {
						[self freeMemory: ret_c];
						[self freeMemory: tmp];
						@throw e;
					}
					memcpy(tmp2, tmp + i + 1, len - i - 1);

					[self freeMemory: cache];
					cache = tmp2;
					cache_len = len - i - 1;
				} else {
					[self freeMemory: cache];
					cache = NULL;
					cache_len = 0;
				}
				[self freeMemory: tmp];

				@try {
					ret = [OFString
					    stringWithCString: ret_c
						     encoding: encoding
						       length: ret_len];
				} @finally {
					[self freeMemory: ret_c];
				}
				return ret;
			}
		}

		/* There was no newline or \0 */
		@try {
			cache = [self resizeMemory: cache
					    toSize: cache_len + len];
		} @catch (OFException *e) {
			[self freeMemory: tmp];
			@throw e;
		}

		/*
		 * It's possible that cache_len + len is 0 and thus cache was
		 * set to NULL by resizeMemory:toSize:.
		 */
		if (cache != NULL)
			memcpy(cache + cache_len, tmp, len);

		cache_len += len;
	}
}

- (size_t)writeNBytes: (size_t)size
	   fromBuffer: (const char*)buf
{
	@throw [OFNotImplementedException newWithClass: isa
					      selector: _cmd];
}

- (size_t)writeString: (OFString*)str
{
	return [self writeNBytes: [str cStringLength]
		      fromBuffer: [str cString]];
}

- close
{
	@throw [OFNotImplementedException newWithClass: isa
					      selector: _cmd];
}
@end