//%LICENSE////////////////////////////////////////////////////////////////
//
// Licensed to The Open Group (TOG) under one or more contributor license
// agreements.  Refer to the OpenPegasusNOTICE.txt file distributed with
// this work for additional information regarding copyright ownership.
// Each contributor licenses this file to you under the OpenPegasus Open
// Source License; you may not use this file except in compliance with the
// License.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included
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//////////////////////////////////////////////////////////////////////////

//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_IDFactory_h
#define Pegasus_IDFactory_h

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/Mutex.h>
#include <Pegasus/Common/Stack.h>
#include <Pegasus/Common/Magic.h>

PEGASUS_NAMESPACE_BEGIN


/** The IDFactory provides a thread-safe interface for assigning unique
    integer identifiers. The getID() method is used to obtain the next unique
    identifier. The putID(), returns a unique identifier to the id pool. Note
    that if putID() is never called, then getID() will assigns a sequence of
    monotonically increasing ids.
*/
class PEGASUS_COMMON_LINKAGE IDFactory
{
public:

    /** Constructor. The firstID argument is the id that is first returned
        by getID().
    */
    IDFactory(Uint32 firstID = 1);

    /** Destructor.
    */
    ~IDFactory();

    /** Obtain the next id.
    */
    Uint32 getID() const;

    /** Return an id to the pool (optional).
    */
    void putID(Uint32 id);

private:

    Magic<0x94E91236> _magic;
    Stack<Uint32> _pool;
    Uint32 _firstID;
    Uint32 _nextID;
    Mutex _mutex;
};

PEGASUS_NAMESPACE_END

#endif /* Pegasus_IDFactory_h */