#ifndef VIRTUALSEEKER_H #define VIRTUALSEEKER_H #include "zipios++/zipios-config.h" #include "zipios++/meta-iostreams.h" namespace zipios { using std::ios ; using std::cerr ; using std::endl ; /** VirtualSeeker is a simple class that keeps track of a set of specified 'virtual' file endings that mark a subset of a real file. An example of its use (and its reason for existence) is to keep track of the file endings of a Zip file embedded in another file. */ class VirtualSeeker { public: inline VirtualSeeker( int start_offset = 0, int end_offset = 0) ; inline void setOffsets( int start_offset, int end_offset ) ; inline void getOffsets( int &start_offset, int &end_offset ) const ; inline int startOffset() const ; inline int endOffset() const ; inline void vseekg( istream &is, int offset, ios::seekdir sd ) const ; inline int vtellg( istream &is ) const ; private: // start and end offsets int _s_off, _e_off ; }; VirtualSeeker::VirtualSeeker( int start_offset, int end_offset ) : _s_off( start_offset ), _e_off( end_offset ) {} void VirtualSeeker::setOffsets( int start_offset, int end_offset ) { _s_off = start_offset ; _e_off = end_offset ; } void VirtualSeeker::getOffsets( int &start_offset, int &end_offset ) const { start_offset = _s_off ; end_offset = _e_off ; } int VirtualSeeker::startOffset() const { return _s_off ; } int VirtualSeeker::endOffset() const { return _e_off ; } void VirtualSeeker::vseekg( istream &is, int offset, ios::seekdir sd ) const { if ( sd == ios::cur ) is.seekg( offset, sd ) ; else if ( sd == ios::beg ) is.seekg( offset + _s_off, sd ) ; else if ( sd == ios::end ) is.seekg( offset - _e_off, sd ) ; else cerr << "VirtualSeekManager::seekg: error - not supposed to happen!" << endl ; } int VirtualSeeker::vtellg( istream &is ) const { return static_cast< int >( is.tellg() ) - _s_off ; } } // namespace #endif /** \file Header file that defines VirtualSeeker. */ /* Zipios++ - a small C++ library that provides easy access to .zip files. Copyright (C) 2000 Thomas Søndergaard This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */