TimeLimitFifo.hxx

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#ifndef RESIP_TimeLimitFifo_hxx
#define RESIP_TimeLimitFifo_hxx 

#include <cassert>
#include <memory>
#include "rutil/AbstractFifo.hxx"
#include <iostream>
#if defined( WIN32 )
#include <time.h>
#endif

// efficiency note: use a circular buffer to avoid list node allocation

// what happens to timers that can't be queued?

namespace resip
{

template<typename Payload>
class Timestamped
{
   public:
      Timestamped(const Payload& msg, time_t n)
         : mMsg(msg),
           mTime(n)
      {}

      inline const Payload& getMsg() const { return mMsg;} 
      inline void setMsg(const Payload& pMsg) { mMsg = pMsg;}
      inline const time_t& getTime() const { return mTime;} 

   private:
      Payload mMsg;
      time_t mTime;
};

template <class Msg>
class TimeLimitFifo : public AbstractFifo< Timestamped<Msg*> >
{
   public:
      typedef enum {EnforceTimeDepth, IgnoreTimeDepth, InternalElement} DepthUsage;

          TimeLimitFifo(unsigned int maxDurationSecs,
                    unsigned int maxSize);

      virtual ~TimeLimitFifo();

      using AbstractFifo< Timestamped<Msg*> >::mFifo;
      using AbstractFifo< Timestamped<Msg*> >::mMutex;
      using AbstractFifo< Timestamped<Msg*> >::mCondition;
      using AbstractFifo< Timestamped<Msg*> >::empty;
      using AbstractFifo< Timestamped<Msg*> >::size;
      using AbstractFifo< Timestamped<Msg*> >::onMessagePushed;

          bool add(Msg* msg, DepthUsage usage);

      Msg* getNext();
      Msg* getNext(int ms);
      
      virtual time_t timeDepth() const;

      
      bool wouldAccept(DepthUsage usage) const;

      void clear();

      virtual size_t getCountDepth() const;
      virtual time_t getTimeDepth() const;
      virtual size_t getCountDepthTolerance() const;
      virtual time_t getTimeDepthTolerance() const;
      virtual void setCountDepthTolerance(unsigned int max);
      virtual void setTimeDepthTolerance(unsigned int maxSecs);

   private:
      time_t timeDepthInternal() const;
      inline bool wouldAcceptInteral(DepthUsage usage) const;
      TimeLimitFifo(const TimeLimitFifo& rhs);
      TimeLimitFifo& operator=(const TimeLimitFifo& rhs);

      time_t mMaxDurationSecs;
      unsigned int mMaxSize;
      unsigned int mUnreservedMaxSize;
};

template <class Msg>
TimeLimitFifo<Msg>::TimeLimitFifo(unsigned int maxDurationSecs,
                                  unsigned int maxSize)
   : AbstractFifo< Timestamped<Msg*> >(),
     mMaxDurationSecs(maxDurationSecs),
     mMaxSize(maxSize),
     mUnreservedMaxSize((int)((maxSize*8)/10)) // !dlb! random guess
{}

template <class Msg>
TimeLimitFifo<Msg>::~TimeLimitFifo()
{
   clear();
   assert(empty());
}

template <class Msg>
bool
TimeLimitFifo<Msg>::add(Msg* msg,
                        DepthUsage usage)
{
   Lock lock(mMutex); (void)lock;

   if (wouldAcceptInteral(usage))
   {
      time_t n = time(0);
      mFifo.push_back(Timestamped<Msg*>(msg, n));
      onMessagePushed(1);
      mCondition.signal();
      return true;
   }
   else
   {
      return false;
   }
}

template <class Msg>
bool
TimeLimitFifo<Msg>::wouldAccept(DepthUsage usage) const
{
   Lock lock(mMutex); (void)lock;

   return wouldAcceptInteral(usage);
}

template <class Msg>
Msg*
TimeLimitFifo<Msg>::getNext()
{
   Timestamped<Msg*> tm(AbstractFifo< Timestamped<Msg*> >::getNext());
   return tm.getMsg();
}

template <class Msg>
Msg*
TimeLimitFifo<Msg>::getNext(int ms)
{
   Timestamped<Msg*> tm(0,0);
   if(AbstractFifo< Timestamped<Msg*> >::getNext(ms, tm))
   {
      return tm.getMsg();
   }
   return 0;
}

template <class Msg>
time_t
TimeLimitFifo<Msg>::timeDepthInternal() const
{
   if(mFifo.empty())
   {
      return 0;
   }

   return time(0) - mFifo.front().getTime();
}

template <class Msg>
bool
TimeLimitFifo<Msg>::wouldAcceptInteral(DepthUsage usage) const
{
   if ((mMaxSize != 0 &&
        mFifo.size() >= mMaxSize))
   {
      return false;
   }

   if (usage == InternalElement)
   {
      return true;
   }

   if (mUnreservedMaxSize != 0 &&
       mFifo.size() >= mUnreservedMaxSize)
   {
      return false;
   }

   if (usage == IgnoreTimeDepth)
   {
      return true;
   }

   assert(usage == EnforceTimeDepth);

   if (mFifo.size() == 0 ||
       mMaxDurationSecs == 0 ||
       timeDepthInternal() < mMaxDurationSecs)
   {
      return true;
   }

   return false;
}

template <class Msg>
time_t
TimeLimitFifo<Msg>::timeDepth() const
{
   Lock lock(mMutex); (void)lock;
   return timeDepthInternal();
}

template <class Msg>
void
TimeLimitFifo<Msg>::clear()
{
   Lock lock(mMutex); (void)lock;

   while (!mFifo.empty())
   {
      delete mFifo.front().getMsg();
      mFifo.pop_front();
   }
}

template <class Msg>
size_t
TimeLimitFifo<Msg>::getCountDepth() const
{
   return size();
}

template <class Msg>
size_t
TimeLimitFifo<Msg>::getCountDepthTolerance() const
{
   return mUnreservedMaxSize;
}

template <class Msg>
time_t 
TimeLimitFifo<Msg>::getTimeDepth() const
{
   return timeDepth();
}

template <class Msg>
time_t
TimeLimitFifo<Msg>::getTimeDepthTolerance() const
{
   return mMaxDurationSecs;
}

template <class Msg>
void
TimeLimitFifo<Msg>::setCountDepthTolerance(unsigned int maxCount)
{
   Lock lock(mMutex); (void)lock;
   mUnreservedMaxSize=int(maxCount * 0.8);
}

template <class Msg>
void
TimeLimitFifo<Msg>::setTimeDepthTolerance(unsigned int maxSecs)
{
   Lock lock(mMutex); (void)lock;

   mMaxDurationSecs=maxSecs;
}


} // namespace resip

#endif

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