source: vscpl/src/hu/varadiistvan/scpl/io/_win32/Overlapped.h@ 30:f043778c833a

// Copyright (c) 2013 by István Váradi

// This file is part of VSCPL, a simple cross-platform utility library

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
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#ifndef HU_VARADIISTVAN_SCPL_IO_WIN32_OVERLAPPED_H
#define HU_VARADIISTVAN_SCPL_IO_WIN32_OVERLAPPED_H
//------------------------------------------------------------------------------

#include "Event.h"

//------------------------------------------------------------------------------

namespace hu { namespace varadiistvan { namespace scpl { namespace io {

//------------------------------------------------------------------------------

/**
 * A wrapper for an OVERLAPPED structure which also has an event
 * associated with it. Instances of this class can be registered into and
 * unregistered from a Waiter. The destructor removes the object from
 * the waiter, if it is registered.
 */
class Overlapped : public Event
{
private:
    /**
     * The Windows OVERLAPPED structure.
     */
    OVERLAPPED overlapped;

public:
    /**
     * Construct the object. The overlapped structure will be reset to
     * 0, and the event handle will be set.
     */
    Overlapped(EventFailable& eventFailable);

    /**
     * Reset the overlapped structure and set its event handle. The
     * event is also cleared.
     */
    void reset();

    /**
     * Get the pointer to the overlapped structure.
     */
    OVERLAPPED* get();

    /**
     * Get the pointer to the overlapped structure.
     */
    const OVERLAPPED* get() const;

    /**
     * Get the result of the overlapped operation.
     *
     * If the operation has completed, the event will be cleared.
     *
     * @param size on successful return, it will contain the number of
     * bytes read or written, which may be 0 for an end-of-file
     * condition
     * @param file the handle of the object on which the operation in
     * question was performed
     *
     * @return true if the operation has completed, or false if it has
     * not, or a failure has occured.
     */
    bool getResult(DWORD& size, HANDLE file);
};

//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------

inline Overlapped::Overlapped(EventFailable& eventFailable) :
    Event(eventFailable)
{
}

//------------------------------------------------------------------------------

inline OVERLAPPED* Overlapped::get()
{
    return &overlapped;
}

//------------------------------------------------------------------------------

inline const OVERLAPPED* Overlapped::get() const
{
    return &overlapped;
}

//------------------------------------------------------------------------------

} /* namespace hu::varadiistvan::scpl::io */ } /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */

//------------------------------------------------------------------------------
#endif // HU_VARADIISTVAN_SCPL_IO_WIN32_OVERLAPPED_H

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