src/fetch-manager.cc - ChronoShare - Gitiles

 /* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
 /*
  * Copyright (c) 2012 University of California, Los Angeles
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation;
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
  *	   Zhenkai Zhu <zhenkai@cs.ucla.edu>
  */

 #include "fetch-manager.h"
 #include <boost/make_shared.hpp>
 #include <boost/ref.hpp>
 #include <boost/throw_exception.hpp>
 #include <boost/lexical_cast.hpp>

 #include "simple-interval-generator.h"
 #include "logging.h"

 INIT_LOGGER ("FetchManager");

 using namespace boost;
 using namespace std;
 using namespace Ccnx;

 static const Name BROADCAST_DOMAIN = Name ("/ndn/broadcast/chronoshare");
 //The disposer object function
 struct fetcher_disposer { void operator() (Fetcher *delete_this) { delete delete_this; } };

 static const string SCHEDULE_FETCHES_TAG = "ScheduleFetches";

 FetchManager::FetchManager (Ccnx::CcnxWrapperPtr ccnx
                 , const Mapping &mapping
                 , uint32_t parallelFetches // = 3
                 , const SegmentCallback &defaultSegmentCallback
                 , const FinishCallback &defaultFinishCallback
                 , const FetchTaskDbPtr &taskDb
                 )
   : m_ccnx (ccnx)
   , m_mapping (mapping)
   , m_maxParallelFetches (parallelFetches)
   , m_currentParallelFetches (0)
   , m_scheduler (new Scheduler)
   , m_executor (new Executor(1))
   , m_defaultSegmentCallback(defaultSegmentCallback)
   , m_defaultFinishCallback(defaultFinishCallback)
   , m_taskDb(taskDb)
 {
   m_scheduler->start ();
   m_executor->start();

   m_scheduleFetchesTask = Scheduler::schedulePeriodicTask (m_scheduler,
                                                            make_shared<SimpleIntervalGenerator> (300), // no need to check to often. if needed, will be rescheduled
                                                            bind (&FetchManager::ScheduleFetches, this), SCHEDULE_FETCHES_TAG);
   // resume un-finished fetches if there is any
   if (m_taskDb)
   {
     m_taskDb->foreachTask(bind(&FetchManager::Enqueue, this, _1, _2, _3, _4, _5));
   }
 }

 FetchManager::~FetchManager ()
 {
   m_scheduler->shutdown ();
   m_executor->shutdown();

   m_ccnx.reset ();

   m_fetchList.clear_and_dispose (fetcher_disposer ());
 }

 // Enqueue using default callbacks
 void
 FetchManager::Enqueue (const Ccnx::Name &deviceName, const Ccnx::Name &baseName,
            uint64_t minSeqNo, uint64_t maxSeqNo, int priority)
 {
   Enqueue(deviceName, baseName, m_defaultSegmentCallback, m_defaultFinishCallback, minSeqNo, maxSeqNo, priority);
 }

 void
 FetchManager::Enqueue (const Ccnx::Name &deviceName, const Ccnx::Name &baseName,
          const SegmentCallback &segmentCallback, const FinishCallback &finishCallback,
          uint64_t minSeqNo, uint64_t maxSeqNo, int priority/*PRIORITY_NORMAL*/)
 {
   // Assumption for the following code is minSeqNo <= maxSeqNo
   if (minSeqNo > maxSeqNo)
   {
     return;
   }

   // we may need to guarantee that LookupLocator will gives an answer and not throw exception...
   Name forwardingHint;
   forwardingHint = m_mapping (deviceName);

   if (m_taskDb)
     {
       m_taskDb->addTask(deviceName, baseName, minSeqNo, maxSeqNo, priority);
     }

   unique_lock<mutex> lock (m_parellelFetchMutex);

   _LOG_TRACE ("++++ Create fetcher: " << baseName);
   Fetcher *fetcher = new Fetcher (m_ccnx,
                                   m_executor,
                                   segmentCallback,
                                   finishCallback,
                                   bind (&FetchManager::DidFetchComplete, this, _1, _2, _3),
                                   bind (&FetchManager::DidNoDataTimeout, this, _1),
                                   deviceName, baseName, minSeqNo, maxSeqNo,
                                   boost::posix_time::seconds (30),
                                   forwardingHint);

   switch (priority)
     {
     case PRIORITY_HIGH:
       _LOG_TRACE ("++++ Push front fetcher: " << fetcher->GetName ());
       m_fetchList.push_front (*fetcher);
       break;

     case PRIORITY_NORMAL:
     default:
       _LOG_TRACE ("++++ Push back fetcher: " << fetcher->GetName ());
       m_fetchList.push_back (*fetcher);
       break;
     }

   _LOG_DEBUG ("++++ Reschedule fetcher task");
   m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
   // ScheduleFetches (); // will start a fetch if m_currentParallelFetches is less than max, otherwise does nothing
 }

 void
 FetchManager::ScheduleFetches ()
 {
   unique_lock<mutex> lock (m_parellelFetchMutex);

   boost::posix_time::ptime currentTime = date_time::second_clock<boost::posix_time::ptime>::universal_time ();
   boost::posix_time::ptime nextSheduleCheck = currentTime + posix_time::seconds (300); // no reason to have anything, but just in case

   for (FetchList::iterator item = m_fetchList.begin ();
        m_currentParallelFetches < m_maxParallelFetches && item != m_fetchList.end ();
        item++)
     {
       if (item->IsActive ())
         {
           _LOG_DEBUG ("Item is active");
           continue;
         }

       if (item->IsTimedWait ())
         {
           _LOG_DEBUG ("Item is in timed-wait");
           continue;
         }

       if (currentTime < item->GetNextScheduledRetry ())
         {
           if (item->GetNextScheduledRetry () < nextSheduleCheck)
             nextSheduleCheck = item->GetNextScheduledRetry ();

           _LOG_DEBUG ("Item is delayed");
           continue;
         }

       _LOG_DEBUG ("Start fetching of " << item->GetName ());

       m_currentParallelFetches ++;
       _LOG_TRACE ("++++ RESTART PIPELINE: " << item->GetName ());
       item->RestartPipeline ();
     }

   m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, (nextSheduleCheck - currentTime).seconds ());
 }

 void
 FetchManager::DidNoDataTimeout (Fetcher &fetcher)
 {
   _LOG_DEBUG ("No data timeout for " << fetcher.GetName () << " with forwarding hint: " << fetcher.GetForwardingHint ());

   {
     unique_lock<mutex> lock (m_parellelFetchMutex);
     m_currentParallelFetches --;
     // no need to do anything with the m_fetchList
   }

   if (fetcher.GetForwardingHint () == BROADCAST_DOMAIN)
     {
       // try again directly (hopefully with different forwarding hint

       /// @todo Handle potential exception
       Name forwardingHint;
       forwardingHint = m_mapping (fetcher.GetDeviceName ());
       fetcher.SetForwardingHint (forwardingHint);
     }
   else
     {
       fetcher.SetForwardingHint (BROADCAST_DOMAIN);
     }

   double delay = fetcher.GetRetryPause ();
   if (delay < 1) // first time
     {
       delay = 1;
     }
   else
     {
       delay = std::min (2*delay, 300.0); // 5 minutes max
     }

   fetcher.SetRetryPause (delay);
   fetcher.SetNextScheduledRetry (date_time::second_clock<boost::posix_time::ptime>::universal_time () + posix_time::seconds (delay));

   m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
 }

 void
 FetchManager::DidFetchComplete (Fetcher &fetcher, const Name &deviceName, const Name &baseName)
 {
   {
     unique_lock<mutex> lock (m_parellelFetchMutex);
     m_currentParallelFetches --;

     if (m_taskDb)
       {
         m_taskDb->deleteTask(deviceName, baseName);
       }
   }

   // like TCP timed-wait
   m_scheduler->scheduleOneTimeTask(m_scheduler, 10, boost::bind(&FetchManager::TimedWait, this, ref(fetcher)), boost::lexical_cast<string>(baseName));

   m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
 }

 void
 FetchManager::TimedWait (Fetcher &fetcher)
 {
     unique_lock<mutex> lock (m_parellelFetchMutex);
     _LOG_TRACE ("+++++ removing fetcher: " << fetcher.GetName ());
     m_fetchList.erase_and_dispose (FetchList::s_iterator_to (fetcher), fetcher_disposer ());
 }
	/* -- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -- */
	/*
	* Copyright (c) 2012 University of California, Los Angeles
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation;
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
	* Zhenkai Zhu <zhenkai@cs.ucla.edu>
	*/

	#include "fetch-manager.h"
	#include <boost/make_shared.hpp>
	#include <boost/ref.hpp>
	#include <boost/throw_exception.hpp>
	#include <boost/lexical_cast.hpp>

	#include "simple-interval-generator.h"
	#include "logging.h"

	INIT_LOGGER ("FetchManager");

	using namespace boost;
	using namespace std;
	using namespace Ccnx;

	static const Name BROADCAST_DOMAIN = Name ("/ndn/broadcast/chronoshare");
	//The disposer object function
	struct fetcher_disposer { void operator() (Fetcher *delete_this) { delete delete_this; } };

	static const string SCHEDULE_FETCHES_TAG = "ScheduleFetches";

	FetchManager::FetchManager (Ccnx::CcnxWrapperPtr ccnx
	, const Mapping &mapping
	, uint32_t parallelFetches // = 3
	, const SegmentCallback &defaultSegmentCallback
	, const FinishCallback &defaultFinishCallback
	, const FetchTaskDbPtr &taskDb
	)
	: m_ccnx (ccnx)
	, m_mapping (mapping)
	, m_maxParallelFetches (parallelFetches)
	, m_currentParallelFetches (0)
	, m_scheduler (new Scheduler)
	, m_executor (new Executor(1))
	, m_defaultSegmentCallback(defaultSegmentCallback)
	, m_defaultFinishCallback(defaultFinishCallback)
	, m_taskDb(taskDb)
	{
	m_scheduler->start ();
	m_executor->start();

	m_scheduleFetchesTask = Scheduler::schedulePeriodicTask (m_scheduler,
	make_shared<SimpleIntervalGenerator> (300), // no need to check to often. if needed, will be rescheduled
	bind (&FetchManager::ScheduleFetches, this), SCHEDULE_FETCHES_TAG);
	// resume un-finished fetches if there is any
	if (m_taskDb)
	{
	m_taskDb->foreachTask(bind(&FetchManager::Enqueue, this, _1, _2, _3, _4, _5));
	}
	}

	FetchManager::~FetchManager ()
	{
	m_scheduler->shutdown ();
	m_executor->shutdown();

	m_ccnx.reset ();

	m_fetchList.clear_and_dispose (fetcher_disposer ());
	}

	// Enqueue using default callbacks
	void
	FetchManager::Enqueue (const Ccnx::Name &deviceName, const Ccnx::Name &baseName,
	uint64_t minSeqNo, uint64_t maxSeqNo, int priority)
	{
	Enqueue(deviceName, baseName, m_defaultSegmentCallback, m_defaultFinishCallback, minSeqNo, maxSeqNo, priority);
	}

	void
	FetchManager::Enqueue (const Ccnx::Name &deviceName, const Ccnx::Name &baseName,
	const SegmentCallback &segmentCallback, const FinishCallback &finishCallback,
	uint64_t minSeqNo, uint64_t maxSeqNo, int priority/PRIORITY_NORMAL/)
	{
	// Assumption for the following code is minSeqNo <= maxSeqNo
	if (minSeqNo > maxSeqNo)
	{
	return;
	}

	// we may need to guarantee that LookupLocator will gives an answer and not throw exception...
	Name forwardingHint;
	forwardingHint = m_mapping (deviceName);

	if (m_taskDb)
	{
	m_taskDb->addTask(deviceName, baseName, minSeqNo, maxSeqNo, priority);
	}

	unique_lock<mutex> lock (m_parellelFetchMutex);

	_LOG_TRACE ("++++ Create fetcher: " << baseName);
	Fetcher *fetcher = new Fetcher (m_ccnx,
	m_executor,
	segmentCallback,
	finishCallback,
	bind (&FetchManager::DidFetchComplete, this, _1, _2, _3),
	bind (&FetchManager::DidNoDataTimeout, this, _1),
	deviceName, baseName, minSeqNo, maxSeqNo,
	boost::posix_time::seconds (30),
	forwardingHint);

	switch (priority)
	{
	case PRIORITY_HIGH:
	_LOG_TRACE ("++++ Push front fetcher: " << fetcher->GetName ());
	m_fetchList.push_front (*fetcher);
	break;

	case PRIORITY_NORMAL:
	default:
	_LOG_TRACE ("++++ Push back fetcher: " << fetcher->GetName ());
	m_fetchList.push_back (*fetcher);
	break;
	}

	_LOG_DEBUG ("++++ Reschedule fetcher task");
	m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
	// ScheduleFetches (); // will start a fetch if m_currentParallelFetches is less than max, otherwise does nothing
	}

	void
	FetchManager::ScheduleFetches ()
	{
	unique_lock<mutex> lock (m_parellelFetchMutex);

	boost::posix_time::ptime currentTime = date_time::second_clock<boost::posix_time::ptime>::universal_time ();
	boost::posix_time::ptime nextSheduleCheck = currentTime + posix_time::seconds (300); // no reason to have anything, but just in case

	for (FetchList::iterator item = m_fetchList.begin ();
	m_currentParallelFetches < m_maxParallelFetches && item != m_fetchList.end ();
	item++)
	{
	if (item->IsActive ())
	{
	_LOG_DEBUG ("Item is active");
	continue;
	}

	if (item->IsTimedWait ())
	{
	_LOG_DEBUG ("Item is in timed-wait");
	continue;
	}

	if (currentTime < item->GetNextScheduledRetry ())
	{
	if (item->GetNextScheduledRetry () < nextSheduleCheck)
	nextSheduleCheck = item->GetNextScheduledRetry ();

	_LOG_DEBUG ("Item is delayed");
	continue;
	}

	_LOG_DEBUG ("Start fetching of " << item->GetName ());

	m_currentParallelFetches ++;
	_LOG_TRACE ("++++ RESTART PIPELINE: " << item->GetName ());
	item->RestartPipeline ();
	}

	m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, (nextSheduleCheck - currentTime).seconds ());
	}

	void
	FetchManager::DidNoDataTimeout (Fetcher &fetcher)
	{
	_LOG_DEBUG ("No data timeout for " << fetcher.GetName () << " with forwarding hint: " << fetcher.GetForwardingHint ());

	{
	unique_lock<mutex> lock (m_parellelFetchMutex);
	m_currentParallelFetches --;
	// no need to do anything with the m_fetchList
	}

	if (fetcher.GetForwardingHint () == BROADCAST_DOMAIN)
	{
	// try again directly (hopefully with different forwarding hint

	/// @todo Handle potential exception
	Name forwardingHint;
	forwardingHint = m_mapping (fetcher.GetDeviceName ());
	fetcher.SetForwardingHint (forwardingHint);
	}
	else
	{
	fetcher.SetForwardingHint (BROADCAST_DOMAIN);
	}

	double delay = fetcher.GetRetryPause ();
	if (delay < 1) // first time
	{
	delay = 1;
	}
	else
	{
	delay = std::min (2*delay, 300.0); // 5 minutes max
	}

	fetcher.SetRetryPause (delay);
	fetcher.SetNextScheduledRetry (date_time::second_clock<boost::posix_time::ptime>::universal_time () + posix_time::seconds (delay));

	m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
	}

	void
	FetchManager::DidFetchComplete (Fetcher &fetcher, const Name &deviceName, const Name &baseName)
	{
	{
	unique_lock<mutex> lock (m_parellelFetchMutex);
	m_currentParallelFetches --;

	if (m_taskDb)
	{
	m_taskDb->deleteTask(deviceName, baseName);
	}
	}

	// like TCP timed-wait
	m_scheduler->scheduleOneTimeTask(m_scheduler, 10, boost::bind(&FetchManager::TimedWait, this, ref(fetcher)), boost::lexical_cast<string>(baseName));

	m_scheduler->rescheduleTaskAt (m_scheduleFetchesTask, 0);
	}

	void
	FetchManager::TimedWait (Fetcher &fetcher)
	{
	unique_lock<mutex> lock (m_parellelFetchMutex);
	_LOG_TRACE ("+++++ removing fetcher: " << fetcher.GetName ());
	m_fetchList.erase_and_dispose (FetchList::s_iterator_to (fetcher), fetcher_disposer ());
	}