FileWrapper.h

/*     Copyright 2015-2018 Egor Yusov
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF ANY PROPRIETARY RIGHTS.
 *
 *  In no event and under no legal theory, whether in tort (including negligence), 
 *  contract, or otherwise, unless required by applicable law (such as deliberate 
 *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
 *  liable for any damages, including any direct, indirect, special, incidental, 
 *  or consequential damages of any character arising as a result of this License or 
 *  out of the use or inability to use the software (including but not limited to damages 
 *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and 
 *  all other commercial damages or losses), even if such Contributor has been advised 
 *  of the possibility of such damages.
 */

#pragma once

#include "FileSystem.h"
#include "Errors.h"
#include "DebugUtilities.h"

namespace Diligent
{

class FileWrapper
{
public:
    FileWrapper( ) : 
        m_pFile(nullptr)
    {}

    FileWrapper( const Diligent::Char *Path, 
                  EFileAccessMode Access = EFileAccessMode::Read) : 
        m_pFile( nullptr )
    {
        FileOpenAttribs OpenAttribs(Path, Access);
        Open(OpenAttribs);
    }

    ~FileWrapper()
    {
        Close();
    }

    void Open(const FileOpenAttribs& OpenAttribs)
    {
        VERIFY( !m_pFile, "Another file already attached" );
        Close();
        m_pFile = FileSystem::OpenFile( OpenAttribs );
    }
    
    CFile *Detach()
    {
        CFile *pFile = m_pFile;
        m_pFile = NULL;
        return pFile;
    }

    void Attach(CFile *pFile)
    {
        VERIFY(!m_pFile, "Another file already attached");
        Close();
        m_pFile = pFile;
    }

    void Close()
    {
        if( m_pFile )
            FileSystem::ReleaseFile(m_pFile);
        m_pFile = nullptr;
    }

    operator CFile*(){return m_pFile;}
    CFile* operator->(){return m_pFile;}

private:
    FileWrapper(const FileWrapper&);
    const FileWrapper& operator=(const FileWrapper&);

    CFile *m_pFile;
};

}