seekabledevice.hpp

// solid/system/seekabledevice.hpp
//
// Copyright (c) 2007, 2008 Valentin Palade (vipalade @ gmail . com)
//
// This file is part of SolidFrame framework.
//
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.
//

#pragma once

#include "device.hpp"

namespace solid {

//! A wrapper for devices with random access.
class SeekableDevice : public Device {
public:
    using Device::read;
    using Device::write;
    //! Read from a given position
    ssize_t read(char* _pb, size_t _bl, int64_t _off);
    //! Write at a given position
    ssize_t write(const char* _pb, size_t _bl, int64_t _off);
    //! Move the cursor to a given position
    int64_t seek(int64_t _pos, SeekRef _ref = SeekBeg);
    //! Truncate to a certain length
    bool truncate(int64_t _len);

protected:
    SeekableDevice(DescriptorT _desc = invalidDescriptor())
        : Device(_desc)
    {
    }
};

} // namespace solid