/* * Copyright (c) 2008, 2009, 2010, 2011, 2012 * 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. */ #ifndef __STDC_LIMIT_MACROS # define __STDC_LIMIT_MACROS #endif #ifndef __STDC_CONSTANT_MACROS # define __STDC_CONSTANT_MACROS #endif #include <sys/types.h> #import "OFStream.h" /** * \brief A stream that supports seeking. * * \note If you want to subclass this, override lowlevelSeekToOffset:, * lowlevelSeekForwardWithOffset: and lowlevelSeekToOffsetRelativeToEnd:, * but nothing else. Those are not defined in the headers, but do the * actual work. OFSeekableStream uses those and makes them work together * with the caching of OFStream. If you override these methods without * the lowlevel prefix, you <i>will</i> break caching, get broken results * and seek to the wrong position! */ @interface OFSeekableStream: OFStream /** * \brief Seeks to the specified absolute offset. * * \param offset The offset in bytes */ - (void)seekToOffset: (off_t)offset; /** * \brief Seeks to the specified offset, relative to the current location. * * \param offset The offset relative to the current location * \return The absolute offset */ - (off_t)seekForwardWithOffset: (off_t)offset; /** * \brief Seeks to the specified offset, relative to the end of the stream. * * \param offset The offset relative to the end of the stream * \return The absolute offset */ - (off_t)seekToOffsetRelativeToEnd: (off_t)offset; /** * \brief Seek the stream on the lowlevel. * * \warning Do not call this directly! * * Override this with this method with your actual seek implementation when * subclassing! * * \param offset The offset to seek to */ - (void)lowlevelSeekToOffset: (off_t)offset; /** * \brief Seek the stream on the lowlevel. * * \warning Do not call this directly! * * Override this with this method with your actual seek implementation when * subclassing! * * \param offset The offset to seek forward to */ - (off_t)lowlevelSeekForwardWithOffset: (off_t)offset; /** * \brief Seek the stream on the lowlevel. * * \warning Do not call this directly! * * Override this with this method with your actual seek implementation when * subclassing! * * \param offset The offset to seek to, relative to the end */ - (off_t)lowlevelSeekToOffsetRelativeToEnd: (off_t)offset; @end