/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
* 2018, 2019, 2020
* Jonathan Schleifer <js@nil.im>
*
* 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.
*/
#ifndef __STDC_LIMIT_MACROS
# define __STDC_LIMIT_MACROS
#endif
#ifndef __STDC_CONSTANT_MACROS
# define __STDC_CONSTANT_MACROS
#endif
#include "objfw-defs.h"
#ifdef OF_HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#import "OFStream.h"
OF_ASSUME_NONNULL_BEGIN
#if defined(OF_WINDOWS)
typedef __int64 of_offset_t;
#elif defined(OF_ANDROID)
typedef long long of_offset_t;
#elif defined(OF_MORPHOS)
typedef signed long long of_offset_t;
#elif defined(OF_HAVE_OFF64_T)
typedef off64_t of_offset_t;
#else
typedef off_t of_offset_t;
#endif
/**
* @class OFSeekableStream OFSeekableStream.h ObjFW/OFSeekableStream.h
*
* @brief A stream that supports seeking.
*
* @note If you want to subclass this, override
* @ref lowlevelSeekToOffset:whence:. OFSeekableStream uses this method
* and makes it work together with the caching of OFStream. If you
* override this methods without the `lowlevel` prefix, you *will* break
* caching, get broken results and seek to the wrong position!
*/
@interface OFSeekableStream: OFStream
{
OF_RESERVE_IVARS(OFSeekableStream, 4)
}
/**
* @brief Seeks to the specified absolute offset.
*
* @param offset The offset in bytes
* @param whence From where to seek.@n
* Possible values are:
* Value | Description
* -----------|---------------------------------------
* `SEEK_SET` | Seek to the specified byte
* `SEEK_CUR` | Seek to the current location + offset
* `SEEK_END` | Seek to the end of the stream + offset
* @return The new offset form the start of the file
*/
- (of_offset_t)seekToOffset: (of_offset_t)offset
whence: (int)whence;
/**
* @brief Seek the stream on the lowlevel.
*
* @warning Do not call this directly!
*
* @note Override this method with your actual seek implementation when
* subclassing!
*
* @param offset The offset to seek to
* @param whence From where to seek.@n
* Possible values are:
* Value | Description
* -----------|---------------------------------------
* `SEEK_SET` | Seek to the specified byte
* `SEEK_CUR` | Seek to the current location + offset
* `SEEK_END` | Seek to the end of the stream + offset
* @return The new offset from the start of the file
*/
- (of_offset_t)lowlevelSeekToOffset: (of_offset_t)offset
whence: (int)whence;
@end
OF_ASSUME_NONNULL_END