file_output_target.hpp

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#ifndef GENESIS_UTILS_IO_FILE_OUTPUT_TARGET_H_
#define GENESIS_UTILS_IO_FILE_OUTPUT_TARGET_H_
 
/*
    Genesis - A toolkit for working with phylogenetic data.
    Copyright (C) 2014-2024 Lucas Czech
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program 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 General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
    Contact:
    Lucas Czech <lucas.czech@sund.ku.dk>
    University of Copenhagen, Globe Institute, Section for GeoGenetics
    Oster Voldgade 5-7, 1350 Copenhagen K, Denmark
*/
 
#include "genesis/utils/core/fs.hpp"
#include "genesis/utils/io/base_output_target.hpp"
#include "genesis/utils/io/output_stream.hpp"
 
#include <fstream>
#include <string>
 
namespace genesis {
namespace utils {
 
// =================================================================================================
//     File Output Target
// =================================================================================================
 
class FileOutputTarget final : public BaseOutputTarget
{
public:
 
    // -------------------------------------------------------------
    //     Constructors and Rule of Five
    // -------------------------------------------------------------
 
    explicit FileOutputTarget(
        std::string const& file_name,
        std::ios_base::openmode mode = std::ios_base::out
    )
        : file_name_( file_name )
        , mode_( mode )
    {}
 
    FileOutputTarget( FileOutputTarget const& ) = delete;
    FileOutputTarget( FileOutputTarget&& )      = default;
 
    FileOutputTarget& operator= ( FileOutputTarget const& ) = delete;
    FileOutputTarget& operator= ( FileOutputTarget&& )      = default;
 
    ~FileOutputTarget() override = default;
 
    // -------------------------------------------------------------
    //     Overloaded Internal Members
    // -------------------------------------------------------------
 
private:
 
    std::ostream& out_stream_() override
    {
        // Lazy loading, in case many output streams are somehow used in a vector or so.
        if( !stream_.is_open() ) {
            // We use our own function to open the stream, to get consistent error checking,
            // as well as the automatic file overwriting check.
            file_output_stream( file_name_, stream_, mode_ );
 
            // We also set a custom buffer, to increase writing speed.
            stream_.rdbuf()->pubsetbuf( stream_buffer_, buffer_size_ );
        }
        return stream_;
    }
 
    std::string target_name_() const override
    {
        return "output file (" + file_name_ + ")";
    }
 
    std::string target_string_() const override
    {
        return file_name_;
    }
 
    // -------------------------------------------------------------
    //     Member Variables
    // -------------------------------------------------------------
 
    // User provided target
    std::string file_name_;
    std::ios_base::openmode mode_ = std::ios_base::out;
 
    // Output stream and buffer of 64KB
    std::ofstream stream_;
    static const size_t buffer_size_ = 1 << 16;
    char stream_buffer_[buffer_size_];
 
};
 
} // namespace utils
} // namespace genesis
 
#endif // include guard