wave-windows.h

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/*
 * wave-windows.h
 *
 * Copyright (C) 2010  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''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 THOMAS A. VAUGHAN 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.
 *
 *
 * Very basic helper routines and classes for working with Windows APIs.
 */

#ifndef WAVEPACKET_WINDOWS_H__
#define WAVEPACKET_WINDOWS_H__

// includes --------------------------------------------------------------------
#include "common/common.h"

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif  // WIN32_LEAN_AND_MEAN

#include <rpc.h>        // windows remote procedure calls


/// \ingroup wavepacket_lib
/*@{*/

////////////////////////////////////////////////////////////////////////////////
///
/// \defgroup wave_windows Microsoft Windows Helper Library
///
/// Very basic routines and classes for working with Windows APIs.
///
////////////////////////////////////////////////////////////////////////////////
/*@{*/

/// helper method to print out information about a particular RPC_STATUS code.
void checkRpcStatus(IN RPC_STATUS rpc_status) throw();

#define RPC_VERIFY(exp, rpc_status, msg)                                \
        if (!(exp)) {                                                   \
                DPRINTF("Windows RPC call failed!");                    \
                checkRpcStatus(rpc_status);                             \
                ASSERT_THROW(false && (exp), msg);                      \
        }


/// helper method to print out information about a particular HRESULT code.
/// Note that this method is often useless since most Windows APIs also
///   define their own (usually redundant) error codes.  So you will have
///   to build your own API-specific error code inspection routine, on top of
///   this generic one.
void checkHresult(IN HRESULT hr) throw();

#define HRESULT_VERIFY(exp, hr, msg)                                    \
        if (!(exp)) {                                                   \
                DPRINTF("Failed windows hresult check!");               \
                checkHresult(hr);                                       \
                ASSERT_THROW(false && (exp), msg);                      \
        }



/// writes an ANSI version of the GUID to the given stream
void writeGuid(IO std::ostream& stream,
                        IN const GUID& guid);

inline std::ostream& operator << (IO std::ostream& stream,
                                  IN const GUID& guid) {
        writeGuid(stream, guid);
        return stream;
}



/// gets GUID as a string and copies as much of it as will fit into the
///     specified buffer.  Use 32+ chars to be safe.  Returns a pointer to
///     the buffer as a convenience.
const char * getGuidString(IN const GUID& guid,
                        IO char * buffer,
                        IN int bufsize);


/// COM_ptr<T>: smart pointer to automatically de-reference COM objects.
/// This object is NOT (automatically) threadsafe.  We are calling
/// IUnknown::AddRef()/Release() on an
/// object, so this pointer is only as threadsafe as the underlying COM object.
/// However, because the object maintains its own count, this pointer is safe
/// to use in collections.
/// \n
/// <b>Semantics of this pointer:</b>
///  - Any raw interface pointer passed will be assumed to already have a
///     reference taken, so AddRef() will not be called again.
///  - Assigning from another COM_ptr<T> will take another AddRef()
///
template <class T>
class COM_ptr {
public:
        // constructor, destructor ---------------------------------------------
        COM_ptr(IN T * pT = NULL) throw() : m_pT(NULL) { this->assign(pT); }

        template <class X>
        COM_ptr(IN const COM_ptr<X>& from) throw() : m_pT(NULL)
            { this->assign(from); }

        ~COM_ptr(void) throw() { this->release(); }

        // public class methods ------------------------------------------------
        T* operator -> (void) throw() {
                        ASSERT(m_pT, "null COM object");
                        return m_pT;
                }

        const T * operator -> (void) const throw() {
                        ASSERT(m_pT, "null COM object");
                        return m_pT;
                }

        operator T* (void) throw() {
                        return m_pT;
                }

        operator const T* (void) const throw() {
                        return m_pT;
                }

        // VisualStudio barfs without a non-const bool() operator (!?)
        operator bool (void) throw() {
                        return !!m_pT;
                }

        operator bool (void) const throw() {
                        return !!m_pT;
                }

        bool operator ! (void) const throw() {
                        return !m_pT;
                }

        operator LPVOID * (void) throw() {
                        ASSERT(!m_pT, "assigning to non-NULL COM ptr");
                        return (LPVOID *) &m_pT;
                }

        const COM_ptr<T>& operator = (IN T * pT) throw() {
                        this->assign(pT);
                        return *this;
                }

        template <class X>
        const COM_ptr<T>& operator = (IN COM_ptr<X>& from) throw() {
                        this->assign(from);
                        return *this;
                }

private:
        // hidden methods ------------------------------------------------------
        // private helper methods ----------------------------------------------
        void assign(IN T * pT) throw() {
                        // NOTE: assumes that a non-null pointer has already had
                        //   a reference taken!
                        // ASSERT(pT) -- can be null!
                        this->release();
                        m_pT = pT;
                }

        template <class X>
        void assign(IN const COM_ptr<X>& from) throw() {
                        // when copying from another COM ptr, we call AddRef
                        this->release();
                        if (from) {
                                // hack cast to avoid constness problems
                                COM_ptr<X> * px = (COM_ptr<X> *) &from;
                                T * pT = dynamic_cast<T *>(px->m_pT);
                                ASSERT(pT, "failed to cast COM object");
                                pT->AddRef();   // take an additional reference
                                this->assign(pT);
                        }
                }

        void release(void) throw() {
                        if (m_pT) {
                                T * pT = m_pT;
                                m_pT = NULL;
                                pT->Release();
                        }
                }

        // private data members ------------------------------------------------
        T *             m_pT;   // actual pointer to COM object
};


#endif  // WAVEPACKET_WINDOWS_H__