handle.hxx

这是国外的resip协议栈

#if !defined(RESIP_HANDLE_HXX)
#define RESIP_HANDLE_HXX

#include <iosfwd>
#include <cassert>
#include "resip/dum/Handled.hxx"
#include "resip/dum/HandleManager.hxx"
#include "resip/dum/HandleException.hxx"

namespace resip
{

template <class T>
class Handle
{
   public:
      Handle(HandleManager& ham, Handled::Id id) : mHam(&ham), mId(id)
      {
      }

      Handle() : mHam(0), mId(0)
      {
      }

      bool isValid() const
      {
         if (!mHam)
         {
            return false;
         }
         else
         {
            return mHam->isValidHandle(mId);
         }
      }
      
      // throws if not found
      T* get()
      {
         if (!mHam)
         {
            //assert(0);
            throw HandleException("Reference to unitialized handle.", __FILE__, __LINE__);
         }
         return static_cast<T*>(mHam->getHandled(mId));
      }

      const T* get() const
      {
         if (!mHam)
         {
            //assert(0);
            throw HandleException("Reference to unitialized handle.", __FILE__, __LINE__);
         }
         return static_cast<T*>(mHam->getHandled(mId));
      }
      
      T* operator->()
      {
         return get();
      }

      const T* operator->() const
      {
         return get();
      }

      T& operator*()
      {
         return *get();
      }

      const T& operator*() const
      {
         return *get();
      }
      

      Handled::Id getId() const
      {
         return mId;
      }

      static Handle<T> NotValid()
      {
         static Handle<T> notValid;
         return notValid;
      }
      
      bool operator==(const Handle<T>& other)
      {
         return (mHam == other.mHam) && (mId == other.mId);
      }
      
      // !nash! to be able to use Handle in Set or Map container
      bool operator<(const Handle<T>& other) const
      {
         assert(mHam);
         assert(other.mHam);
         return mId < other.mId;
      }

   private:
      HandleManager* mHam;

   protected:
      Handled::Id mId;

      friend class Handled;
};

}

#endif

/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
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 *    notice, this list of conditions and the following disclaimer.
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 *    distribution.
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 *    permission, please contact [e-mail].
 *
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