file_stream.h

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// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; eval: (progn (c-set-style "stroustrup") (c-set-offset 'innamespace 0)); -*-
// vi:set ts=4 sts=4 sw=4 noet :
// Copyright 2009, 2011, The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE 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 3 of the License, or (at your
// option) any later version.
// 
// TPIE 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 TPIE.  If not, see <http://www.gnu.org/licenses/>
#ifndef __TPIE_FILE_STREAM_H__
#define __TPIE_FILE_STREAM_H__
#include <tpie/tempname.h>
#include <tpie/file.h>
#include <tpie/memory.h>
#include <tpie/file_stream_base.h>

namespace tpie {


template <typename T>
class file_stream: public file_stream_base {
public:
    typedef T item_type;

    inline file_stream(double blockFactor=1.0, 
                       file_accessor::file_accessor * fileAccessor=NULL):
        file_stream_base(sizeof(item_type), blockFactor, fileAccessor) {};

    
    inline void write(const item_type & item) throw(stream_exception) {
        assert(m_open);
#ifndef NDEBUG
        if (!is_writable())
            throw io_exception("Cannot write to read only stream");
#endif
        if (m_index >= m_blockItems) update_block();
        reinterpret_cast<item_type*>(m_block.data)[m_index++] = item;
        write_update();
    }

    template <typename IT>
    inline void write(const IT & start, const IT & end) throw(stream_exception) {
        assert(m_open);
        write_array(*this, start, end);
    }

    inline const item_type & read() throw(stream_exception) {
        assert(m_open);
        if (m_index >= m_block.size) {
            update_block();
            if (offset() >= size()) {
                throw end_of_stream_exception();
            }
        }
        return reinterpret_cast<item_type*>(m_block.data)[m_index++];
    }

    template <typename IT>
    inline void read(const IT & start, const IT & end) throw(stream_exception) {
        assert(m_open);
        read_array(*this, start, end);
    }

    inline const item_type & read_back() throw(stream_exception) {
        assert(m_open);
        seek(-1, current);
        const item_type & i = read();
        seek(-1, current);
        return i;
    }

    inline static memory_size_type memory_usage(
        float blockFactor=1.0,
        bool includeDefaultFileAccessor=true) throw() {
        // TODO
        memory_size_type x = sizeof(file_stream);
        x += block_memory_usage(blockFactor); // allocated in constructor
        if (includeDefaultFileAccessor)
            x += default_file_accessor::memory_usage();
        return x;
    }

    void swap(file_stream<T> & other) {
        file_stream_base::swap(other);
    }

    friend struct stream_item_array_operations;
};

} // namespace tpie

namespace std {

template <typename T>
void swap(tpie::file_stream<T> & a, tpie::file_stream<T> & b) {
    a.swap(b);
}

} // namespace std

#endif //__TPIE_FILE_STREAM_H__