FileDataReader.hpp

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/* 
 * FileDataReader.hpp 
 *
 * This file is part of the Chemical Data Processing Toolkit
 *
 * Copyright (C) 2003 Thomas Seidel <thomas.seidel@univie.ac.at>
 *
 * 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; see the file COPYING. If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
 
#ifndef CDPL_UTIL_FILEDATAREADER_HPP
#define CDPL_UTIL_FILEDATAREADER_HPP
 
#include <fstream>
#include <string>
#include <functional>
 
#include "CDPL/Base/DataReader.hpp"
#include "CDPL/Base/Exceptions.hpp"
 
 
namespace CDPL
{
 
    namespace Util
    {
 
        template <typename ReaderImpl, typename DataType = typename ReaderImpl::DataType>
        class FileDataReader : public Base::DataReader<DataType>
        {
 
          public:
            FileDataReader(const std::string&      file_name,
                           std::ios_base::openmode mode = std::ios_base::in | std::ios_base::binary);
 
            FileDataReader& read(DataType& obj, bool overwrite = true);
 
            FileDataReader& read(std::size_t idx, DataType& obj, bool overwrite = true);
 
            FileDataReader& skip();
 
            bool hasMoreData();
 
            std::size_t getRecordIndex() const;
 
            void setRecordIndex(std::size_t idx);
 
            std::size_t getNumRecords();
 
            operator const void*() const;
 
            bool operator!() const;
 
            void close();
 
          private:
            std::ifstream stream;
            std::string   fileName;
            ReaderImpl    reader;
        };
    } // namespace Util
} // namespace CDPL
 
 
// Implementation
 
template <typename ReaderImpl, typename DataType>
CDPL::Util::FileDataReader<ReaderImpl, DataType>::FileDataReader(const std::string& file_name, std::ios_base::openmode mode):
    stream(file_name.c_str(), mode), fileName(file_name), reader(stream)
{
    if (!stream.good())
        throw Base::IOError("FileDataReader: could not open file");
 
    reader.setParent(this);
    reader.registerIOCallback(std::bind(&Base::DataIOBase::invokeIOCallbacks, this, std::placeholders::_2));
}
 
template <typename ReaderImpl, typename DataType>
CDPL::Util::FileDataReader<ReaderImpl, DataType>&
CDPL::Util::FileDataReader<ReaderImpl, DataType>::read(DataType& obj, bool overwrite)
{
    try {
        reader.read(obj, overwrite);
 
    } catch (const std::exception& e) {
        throw Base::IOError("FileDataReader: while reading file '" + fileName + "': " + e.what());
    }
 
    return *this;
}
 
template <typename ReaderImpl, typename DataType>
CDPL::Util::FileDataReader<ReaderImpl, DataType>&
CDPL::Util::FileDataReader<ReaderImpl, DataType>::read(std::size_t idx, DataType& obj, bool overwrite)
{
    try {
        reader.read(idx, obj, overwrite);
 
    } catch (const std::exception& e) {
        throw Base::IOError("FileDataReader: while reading file '" + fileName + "': " + e.what());
    }
 
    return *this;
}
 
template <typename ReaderImpl, typename DataType>
CDPL::Util::FileDataReader<ReaderImpl, DataType>&
CDPL::Util::FileDataReader<ReaderImpl, DataType>::skip()
{
    try {
        reader.skip();
 
    } catch (const std::exception& e) {
        throw Base::IOError("FileDataReader: while reading file '" + fileName + "': " + e.what());
    }
 
    return *this;
}
 
template <typename ReaderImpl, typename DataType>
bool CDPL::Util::FileDataReader<ReaderImpl, DataType>::hasMoreData()
{
    return reader.hasMoreData();
}
 
template <typename ReaderImpl, typename DataType>
std::size_t CDPL::Util::FileDataReader<ReaderImpl, DataType>::getRecordIndex() const
{
    return reader.getRecordIndex();
}
 
template <typename ReaderImpl, typename DataType>
void CDPL::Util::FileDataReader<ReaderImpl, DataType>::setRecordIndex(std::size_t idx)
{
    reader.setRecordIndex(idx);
}
 
template <typename ReaderImpl, typename DataType>
std::size_t CDPL::Util::FileDataReader<ReaderImpl, DataType>::getNumRecords()
{
    return reader.getNumRecords();
}
 
template <typename ReaderImpl, typename DataType>
CDPL::Util::FileDataReader<ReaderImpl, DataType>::operator const void*() const
{
    return reader.operator const void*();
}
 
template <typename ReaderImpl, typename DataType>
bool CDPL::Util::FileDataReader<ReaderImpl, DataType>::operator!() const
{
    return reader.operator!();
}
 
template <typename ReaderImpl, typename DataType>
void CDPL::Util::FileDataReader<ReaderImpl, DataType>::close()
{
    reader.close();
    stream.close();
}
 
#endif // CDPL_UTIL_FILEDATAREADER_HPP