src/handles/write-handle.cpp - repo-ng - Gitiles

 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
  * Copyright (c) 2014-2018, Regents of the University of California.
  *
  * This file is part of NDN repo-ng (Next generation of NDN repository).
  * See AUTHORS.md for complete list of repo-ng authors and contributors.
  *
  * repo-ng is free software: you can redistribute it and/or modify it under the terms
  * of the GNU General Public License as published by the Free Software Foundation,
  * either version 3 of the License, or (at your option) any later version.
  *
  * repo-ng 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
  * repo-ng, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include "write-handle.hpp"

 namespace repo {

 static const int RETRY_TIMEOUT = 3;
 static const int DEFAULT_CREDIT = 12;
 static const milliseconds NOEND_TIMEOUT(10000);
 static const milliseconds PROCESS_DELETE_TIME(10000);
 static const milliseconds DEFAULT_INTEREST_LIFETIME(4000);

 WriteHandle::WriteHandle(Face& face, RepoStorage& storageHandle, KeyChain& keyChain,
                          Scheduler& scheduler,
                          Validator& validator)
   : BaseHandle(face, storageHandle, keyChain, scheduler)
   , m_validator(validator)
   , m_retryTime(RETRY_TIMEOUT)
   , m_credit(DEFAULT_CREDIT)
   , m_noEndTimeout(NOEND_TIMEOUT)
   , m_interestLifetime(DEFAULT_INTEREST_LIFETIME)
 {
 }

 void
 WriteHandle::deleteProcess(ProcessId processId)
 {
   m_processes.erase(processId);
 }

 // Interest.
 void
 WriteHandle::onInterest(const Name& prefix, const Interest& interest)
 {
   m_validator.validate(interest,
                        bind(&WriteHandle::onValidated, this, _1, prefix),
                        bind(&WriteHandle::onValidationFailed, this, _1, _2));
 }

 void
 WriteHandle::onValidated(const Interest& interest, const Name& prefix)
 {
   RepoCommandParameter parameter;
   try {
     extractParameter(interest, prefix, parameter);
   }
   catch (const RepoCommandParameter::Error&) {
     negativeReply(interest, 403);
     return;
   }

   if (parameter.hasStartBlockId() || parameter.hasEndBlockId()) {
     if (parameter.hasSelectors()) {
       negativeReply(interest, 402);
       return;
     }
     processSegmentedInsertCommand(interest, parameter);
   }
   else {
     processSingleInsertCommand(interest, parameter);
   }
   if (parameter.hasInterestLifetime())
     m_interestLifetime = parameter.getInterestLifetime();
 }

 void
 WriteHandle::onValidationFailed(const Interest& interest, const ValidationError& error)
 {
   std::cerr << error << std::endl;
   negativeReply(interest, 401);
 }

 void
 WriteHandle::onData(const Interest& interest, const Data& data, ProcessId processId)
 {
   m_validator.validate(data,
                        bind(&WriteHandle::onDataValidated, this, interest, _1, processId),
                        bind(&WriteHandle::onDataValidationFailed, this, _1, _2));
 }

 void
 WriteHandle::onDataValidated(const Interest& interest, const Data& data, ProcessId processId)
 {
   if (m_processes.count(processId) == 0) {
     return;
   }

   ProcessInfo& process = m_processes[processId];
   RepoCommandResponse& response = process.response;

   if (response.getInsertNum() == 0) {
     getStorageHandle().insertData(data);
    // getStorageHandle().insertEntry(data);
    // getStoreIndex().insert(data);
     response.setInsertNum(1);
   }

   deferredDeleteProcess(processId);
 }

 void
 WriteHandle::onDataValidationFailed(const Data& data, const ValidationError& error)
 {
   std::cerr << error << std::endl;
 }

 void
 WriteHandle::onSegmentData(const Interest& interest, const Data& data, ProcessId processId)
 {
   m_validator.validate(data,
                        bind(&WriteHandle::onSegmentDataValidated, this, interest, _1, processId),
                        bind(&WriteHandle::onDataValidationFailed, this, _1, _2));
 }

 void
 WriteHandle::onSegmentDataValidated(const Interest& interest, const Data& data, ProcessId processId)
 {
   auto it = m_processes.find(processId);
   if (it == m_processes.end()) {
     return;
   }
   RepoCommandResponse& response = it->second.response;

   //refresh endBlockId
   auto finalBlock = data.getFinalBlock();
   if (finalBlock && finalBlock->isSegment()) {
     auto finalSeg = finalBlock->toSegment();
     if (response.hasEndBlockId()) {
       if (finalSeg < response.getEndBlockId()) {
         response.setEndBlockId(finalSeg);
       }
     }
     else {
       response.setEndBlockId(finalSeg);
     }
   }

   //insert data
   if (getStorageHandle().insertData(data)) {
     response.setInsertNum(response.getInsertNum() + 1);
   }

   onSegmentDataControl(processId, interest);
 }

 void
 WriteHandle::onTimeout(const Interest& interest, ProcessId processId)
 {
   std::cerr << "Timeout" << std::endl;
   m_processes.erase(processId);
 }

 void
 WriteHandle::onSegmentTimeout(const Interest& interest, ProcessId processId)
 {
   std::cerr << "SegTimeout" << std::endl;

   onSegmentTimeoutControl(processId, interest);
 }

 void
 WriteHandle::listen(const Name& prefix)
 {
   getFace().setInterestFilter(Name(prefix).append("insert"),
                               bind(&WriteHandle::onInterest, this, _1, _2));
   getFace().setInterestFilter(Name(prefix).append("insert check"),
                               bind(&WriteHandle::onCheckInterest, this, _1, _2));
 }

 void
 WriteHandle::segInit(ProcessId processId, const RepoCommandParameter& parameter)
 {
   ProcessInfo& process = m_processes[processId];
   process.credit = 0;

   map<SegmentNo, int>& processRetry = process.retryCounts;

   Name name = parameter.getName();
   SegmentNo startBlockId = parameter.getStartBlockId();

   uint64_t initialCredit = m_credit;

   if (parameter.hasEndBlockId()) {
     initialCredit =
       std::min(initialCredit, parameter.getEndBlockId() - parameter.getStartBlockId() + 1);
   }
   else {
     // set noEndTimeout timer
     process.noEndTime = ndn::time::steady_clock::now() +
                         m_noEndTimeout;
   }
   process.credit = initialCredit;
   SegmentNo segment = startBlockId;

   for (; segment < startBlockId + initialCredit; ++segment) {
     Name fetchName = name;
     fetchName.appendSegment(segment);
     Interest interest(fetchName);
     interest.setInterestLifetime(m_interestLifetime);
     getFace().expressInterest(interest,
                               bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
                               bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
                               bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
     process.credit--;
     processRetry[segment] = 0;
   }

   queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;

   process.nextSegment = segment;
   nextSegmentQueue.push(segment);
 }

 void
 WriteHandle::onSegmentDataControl(ProcessId processId, const Interest& interest)
 {
   if (m_processes.count(processId) == 0) {
     return;
   }
   ProcessInfo& process = m_processes[processId];
   RepoCommandResponse& response = process.response;
   int& processCredit = process.credit;
   //onSegmentDataControl is called when a data returns.
   //When data returns, processCredit++
   processCredit++;
   SegmentNo& nextSegment = process.nextSegment;
   queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;
   map<SegmentNo, int>& retryCounts = process.retryCounts;

   //read whether notime timeout
   if (!response.hasEndBlockId()) {

     ndn::time::steady_clock::TimePoint& noEndTime = process.noEndTime;
     ndn::time::steady_clock::TimePoint now = ndn::time::steady_clock::now();

     if (now > noEndTime) {
       std::cerr << "noEndtimeout: " << processId << std::endl;
       //m_processes.erase(processId);
       //StatusCode should be refreshed as 405
       response.setStatusCode(405);
       //schedule a delete event
       deferredDeleteProcess(processId);
       return;
     }
   }

   //read whether this process has total ends, if ends, remove control info from the maps
   if (response.hasEndBlockId()) {
     uint64_t nSegments =
       response.getEndBlockId() - response.getStartBlockId() + 1;
     if (response.getInsertNum() >= nSegments) {
       //m_processes.erase(processId);
       //All the data has been inserted, StatusCode is refreshed as 200
       response.setStatusCode(200);
       deferredDeleteProcess(processId);
       return;
     }
   }

   //check whether there is any credit
   if (processCredit == 0)
     return;


   //check whether sent queue empty
   if (nextSegmentQueue.empty()) {
     //do not do anything
     return;
   }

   //pop the queue
   SegmentNo sendingSegment = nextSegmentQueue.front();
   nextSegmentQueue.pop();

   //check whether sendingSegment exceeds
   if (response.hasEndBlockId() && sendingSegment > response.getEndBlockId()) {
     //do not do anything
     return;
   }

   //read whether this is retransmitted data;
   SegmentNo fetchedSegment =
     interest.getName().get(interest.getName().size() - 1).toSegment();

   BOOST_ASSERT(retryCounts.count(fetchedSegment) != 0);

   //find this fetched data, remove it from this map
   //rit->second.erase(oit);
   retryCounts.erase(fetchedSegment);
   //express the interest of the top of the queue
   Name fetchName(interest.getName().getPrefix(-1));
   fetchName.appendSegment(sendingSegment);
   Interest fetchInterest(fetchName);
   fetchInterest.setInterestLifetime(m_interestLifetime);
   getFace().expressInterest(fetchInterest,
                             bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
                             bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
                             bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
   //When an interest is expressed, processCredit--
   processCredit--;
   if (retryCounts.count(sendingSegment) == 0) {
     //not found
     retryCounts[sendingSegment] = 0;
   }
   else {
     //found
     retryCounts[sendingSegment] = retryCounts[sendingSegment] + 1;
   }
   //increase the next seg and put it into the queue
   if (!response.hasEndBlockId() || (nextSegment + 1) <= response.getEndBlockId()) {
     nextSegment++;
     nextSegmentQueue.push(nextSegment);
   }
 }

 void
 WriteHandle::onSegmentTimeoutControl(ProcessId processId, const Interest& interest)
 {
   if (m_processes.count(processId) == 0) {
     return;
   }
   ProcessInfo& process = m_processes[processId];
   // RepoCommandResponse& response = process.response;
   // SegmentNo& nextSegment = process.nextSegment;
   // queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;
   map<SegmentNo, int>& retryCounts = process.retryCounts;

   SegmentNo timeoutSegment = interest.getName().get(-1).toSegment();

   std::cerr << "timeoutSegment: " << timeoutSegment << std::endl;

   BOOST_ASSERT(retryCounts.count(timeoutSegment) != 0);

   //read the retry time. If retry out of time, fail the process. if not, plus
   int& retryTime = retryCounts[timeoutSegment];
   if (retryTime >= m_retryTime) {
     //fail this process
     std::cerr << "Retry timeout: " << processId << std::endl;
     m_processes.erase(processId);
     return;
   }
   else {
     //Reput it in the queue, retryTime++
     retryTime++;
     Interest retryInterest(interest.getName());
     retryInterest.setInterestLifetime(m_interestLifetime);
     getFace().expressInterest(retryInterest,
                               bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
                               bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
                               bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
   }

 }

 void
 WriteHandle::onCheckInterest(const Name& prefix, const Interest& interest)
 {
   m_validator.validate(interest,
                        bind(&WriteHandle::onCheckValidated, this, _1, prefix),
                        bind(&WriteHandle::onCheckValidationFailed, this, _1, _2));

 }

 void
 WriteHandle::onCheckValidated(const Interest& interest, const Name& prefix)
 {
   RepoCommandParameter parameter;
   try {
     extractParameter(interest, prefix, parameter);
   }
   catch (const RepoCommandParameter::Error&) {
     negativeReply(interest, 403);
     return;
   }

   if (!parameter.hasProcessId()) {
     negativeReply(interest, 403);
     return;
   }
   //check whether this process exists
   ProcessId processId = parameter.getProcessId();
   if (m_processes.count(processId) == 0) {
     std::cerr << "no such processId: " << processId << std::endl;
     negativeReply(interest, 404);
     return;
   }

   ProcessInfo& process = m_processes[processId];

   RepoCommandResponse& response = process.response;

   //Check whether it is single data fetching
   if (!response.hasStartBlockId() &&
       !response.hasEndBlockId()) {
     reply(interest, response);
     return;
   }

   //read if noEndtimeout
   if (!response.hasEndBlockId()) {
     extendNoEndTime(process);
     reply(interest, response);
     return;
   }
   else {
     reply(interest, response);
   }
 }

 void
 WriteHandle::onCheckValidationFailed(const Interest& interest, const ValidationError& error)
 {
   std::cerr << error << std::endl;
   negativeReply(interest, 401);
 }

 void
 WriteHandle::deferredDeleteProcess(ProcessId processId)
 {
   getScheduler().scheduleEvent(PROCESS_DELETE_TIME,
                                bind(&WriteHandle::deleteProcess, this, processId));
 }

 void
 WriteHandle::processSingleInsertCommand(const Interest& interest,
                                         RepoCommandParameter& parameter)
 {
   ProcessId processId = generateProcessId();

   ProcessInfo& process = m_processes[processId];

   RepoCommandResponse& response = process.response;
   response.setStatusCode(100);
   response.setProcessId(processId);
   response.setInsertNum(0);

   reply(interest, response);

   response.setStatusCode(300);

   Interest fetchInterest(parameter.getName());
   fetchInterest.setInterestLifetime(m_interestLifetime);
   if (parameter.hasSelectors()) {
     fetchInterest.setSelectors(parameter.getSelectors());
   }
   getFace().expressInterest(fetchInterest,
                             bind(&WriteHandle::onData, this, _1, _2, processId),
                             bind(&WriteHandle::onTimeout, this, _1, processId), // Nack
                             bind(&WriteHandle::onTimeout, this, _1, processId));
 }

 void
 WriteHandle::processSegmentedInsertCommand(const Interest& interest,
                                            RepoCommandParameter& parameter)
 {
   if (parameter.hasEndBlockId()) {
     //normal fetch segment
     if (!parameter.hasStartBlockId()) {
       parameter.setStartBlockId(0);
     }

     SegmentNo startBlockId = parameter.getStartBlockId();
     SegmentNo endBlockId = parameter.getEndBlockId();
     if (startBlockId > endBlockId) {
       negativeReply(interest, 403);
       return;
     }

     ProcessId processId = generateProcessId();
     ProcessInfo& process = m_processes[processId];
     RepoCommandResponse& response = process.response;
     response.setStatusCode(100);
     response.setProcessId(processId);
     response.setInsertNum(0);
     response.setStartBlockId(startBlockId);
     response.setEndBlockId(endBlockId);

     reply(interest, response);

     //300 means data fetching is in progress
     response.setStatusCode(300);

     segInit(processId, parameter);
   }
   else {
     //no EndBlockId, so fetch FinalBlockId in data, if timeout, stop
     ProcessId processId = generateProcessId();
     ProcessInfo& process = m_processes[processId];
     RepoCommandResponse& response = process.response;
     response.setStatusCode(100);
     response.setProcessId(processId);
     response.setInsertNum(0);
     response.setStartBlockId(parameter.getStartBlockId());
     reply(interest, response);

     //300 means data fetching is in progress
     response.setStatusCode(300);

     segInit(processId, parameter);
   }
 }

 void
 WriteHandle::extendNoEndTime(ProcessInfo& process)
 {
   ndn::time::steady_clock::TimePoint& noEndTime = process.noEndTime;
   ndn::time::steady_clock::TimePoint now = ndn::time::steady_clock::now();
   RepoCommandResponse& response = process.response;
   if (now > noEndTime) {
     response.setStatusCode(405);
     return;
   }
   //extends noEndTime
   process.noEndTime =
     ndn::time::steady_clock::now() + m_noEndTimeout;

 }

 void
 WriteHandle::negativeReply(const Interest& interest, int statusCode)
 {
   RepoCommandResponse response;
   response.setStatusCode(statusCode);
   reply(interest, response);
 }

 } // namespace repo
	/* -- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -- */
	/*
	* Copyright (c) 2014-2018, Regents of the University of California.
	*
	* This file is part of NDN repo-ng (Next generation of NDN repository).
	* See AUTHORS.md for complete list of repo-ng authors and contributors.
	*
	* repo-ng is free software: you can redistribute it and/or modify it under the terms
	* of the GNU General Public License as published by the Free Software Foundation,
	* either version 3 of the License, or (at your option) any later version.
	*
	* repo-ng 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
	* repo-ng, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include "write-handle.hpp"

	namespace repo {

	static const int RETRY_TIMEOUT = 3;
	static const int DEFAULT_CREDIT = 12;
	static const milliseconds NOEND_TIMEOUT(10000);
	static const milliseconds PROCESS_DELETE_TIME(10000);
	static const milliseconds DEFAULT_INTEREST_LIFETIME(4000);

	WriteHandle::WriteHandle(Face& face, RepoStorage& storageHandle, KeyChain& keyChain,
	Scheduler& scheduler,
	Validator& validator)
	: BaseHandle(face, storageHandle, keyChain, scheduler)
	, m_validator(validator)
	, m_retryTime(RETRY_TIMEOUT)
	, m_credit(DEFAULT_CREDIT)
	, m_noEndTimeout(NOEND_TIMEOUT)
	, m_interestLifetime(DEFAULT_INTEREST_LIFETIME)
	{
	}

	void
	WriteHandle::deleteProcess(ProcessId processId)
	{
	m_processes.erase(processId);
	}

	// Interest.
	void
	WriteHandle::onInterest(const Name& prefix, const Interest& interest)
	{
	m_validator.validate(interest,
	bind(&WriteHandle::onValidated, this, _1, prefix),
	bind(&WriteHandle::onValidationFailed, this, _1, _2));
	}

	void
	WriteHandle::onValidated(const Interest& interest, const Name& prefix)
	{
	RepoCommandParameter parameter;
	try {
	extractParameter(interest, prefix, parameter);
	}
	catch (const RepoCommandParameter::Error&) {
	negativeReply(interest, 403);
	return;
	}

	if (parameter.hasStartBlockId() \|\| parameter.hasEndBlockId()) {
	if (parameter.hasSelectors()) {
	negativeReply(interest, 402);
	return;
	}
	processSegmentedInsertCommand(interest, parameter);
	}
	else {
	processSingleInsertCommand(interest, parameter);
	}
	if (parameter.hasInterestLifetime())
	m_interestLifetime = parameter.getInterestLifetime();
	}

	void
	WriteHandle::onValidationFailed(const Interest& interest, const ValidationError& error)
	{
	std::cerr << error << std::endl;
	negativeReply(interest, 401);
	}

	void
	WriteHandle::onData(const Interest& interest, const Data& data, ProcessId processId)
	{
	m_validator.validate(data,
	bind(&WriteHandle::onDataValidated, this, interest, _1, processId),
	bind(&WriteHandle::onDataValidationFailed, this, _1, _2));
	}

	void
	WriteHandle::onDataValidated(const Interest& interest, const Data& data, ProcessId processId)
	{
	if (m_processes.count(processId) == 0) {
	return;
	}

	ProcessInfo& process = m_processes[processId];
	RepoCommandResponse& response = process.response;

	if (response.getInsertNum() == 0) {
	getStorageHandle().insertData(data);
	// getStorageHandle().insertEntry(data);
	// getStoreIndex().insert(data);
	response.setInsertNum(1);
	}

	deferredDeleteProcess(processId);
	}

	void
	WriteHandle::onDataValidationFailed(const Data& data, const ValidationError& error)
	{
	std::cerr << error << std::endl;
	}

	void
	WriteHandle::onSegmentData(const Interest& interest, const Data& data, ProcessId processId)
	{
	m_validator.validate(data,
	bind(&WriteHandle::onSegmentDataValidated, this, interest, _1, processId),
	bind(&WriteHandle::onDataValidationFailed, this, _1, _2));
	}

	void
	WriteHandle::onSegmentDataValidated(const Interest& interest, const Data& data, ProcessId processId)
	{
	auto it = m_processes.find(processId);
	if (it == m_processes.end()) {
	return;
	}
	RepoCommandResponse& response = it->second.response;

	//refresh endBlockId
	auto finalBlock = data.getFinalBlock();
	if (finalBlock && finalBlock->isSegment()) {
	auto finalSeg = finalBlock->toSegment();
	if (response.hasEndBlockId()) {
	if (finalSeg < response.getEndBlockId()) {
	response.setEndBlockId(finalSeg);
	}
	}
	else {
	response.setEndBlockId(finalSeg);
	}
	}

	//insert data
	if (getStorageHandle().insertData(data)) {
	response.setInsertNum(response.getInsertNum() + 1);
	}

	onSegmentDataControl(processId, interest);
	}

	void
	WriteHandle::onTimeout(const Interest& interest, ProcessId processId)
	{
	std::cerr << "Timeout" << std::endl;
	m_processes.erase(processId);
	}

	void
	WriteHandle::onSegmentTimeout(const Interest& interest, ProcessId processId)
	{
	std::cerr << "SegTimeout" << std::endl;

	onSegmentTimeoutControl(processId, interest);
	}

	void
	WriteHandle::listen(const Name& prefix)
	{
	getFace().setInterestFilter(Name(prefix).append("insert"),
	bind(&WriteHandle::onInterest, this, _1, _2));
	getFace().setInterestFilter(Name(prefix).append("insert check"),
	bind(&WriteHandle::onCheckInterest, this, _1, _2));
	}

	void
	WriteHandle::segInit(ProcessId processId, const RepoCommandParameter& parameter)
	{
	ProcessInfo& process = m_processes[processId];
	process.credit = 0;

	map<SegmentNo, int>& processRetry = process.retryCounts;

	Name name = parameter.getName();
	SegmentNo startBlockId = parameter.getStartBlockId();

	uint64_t initialCredit = m_credit;

	if (parameter.hasEndBlockId()) {
	initialCredit =
	std::min(initialCredit, parameter.getEndBlockId() - parameter.getStartBlockId() + 1);
	}
	else {
	// set noEndTimeout timer
	process.noEndTime = ndn::time::steady_clock::now() +
	m_noEndTimeout;
	}
	process.credit = initialCredit;
	SegmentNo segment = startBlockId;

	for (; segment < startBlockId + initialCredit; ++segment) {
	Name fetchName = name;
	fetchName.appendSegment(segment);
	Interest interest(fetchName);
	interest.setInterestLifetime(m_interestLifetime);
	getFace().expressInterest(interest,
	bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
	process.credit--;
	processRetry[segment] = 0;
	}

	queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;

	process.nextSegment = segment;
	nextSegmentQueue.push(segment);
	}

	void
	WriteHandle::onSegmentDataControl(ProcessId processId, const Interest& interest)
	{
	if (m_processes.count(processId) == 0) {
	return;
	}
	ProcessInfo& process = m_processes[processId];
	RepoCommandResponse& response = process.response;
	int& processCredit = process.credit;
	//onSegmentDataControl is called when a data returns.
	//When data returns, processCredit++
	processCredit++;
	SegmentNo& nextSegment = process.nextSegment;
	queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;
	map<SegmentNo, int>& retryCounts = process.retryCounts;

	//read whether notime timeout
	if (!response.hasEndBlockId()) {

	ndn::time::steady_clock::TimePoint& noEndTime = process.noEndTime;
	ndn::time::steady_clock::TimePoint now = ndn::time::steady_clock::now();

	if (now > noEndTime) {
	std::cerr << "noEndtimeout: " << processId << std::endl;
	//m_processes.erase(processId);
	//StatusCode should be refreshed as 405
	response.setStatusCode(405);
	//schedule a delete event
	deferredDeleteProcess(processId);
	return;
	}
	}

	//read whether this process has total ends, if ends, remove control info from the maps
	if (response.hasEndBlockId()) {
	uint64_t nSegments =
	response.getEndBlockId() - response.getStartBlockId() + 1;
	if (response.getInsertNum() >= nSegments) {
	//m_processes.erase(processId);
	//All the data has been inserted, StatusCode is refreshed as 200
	response.setStatusCode(200);
	deferredDeleteProcess(processId);
	return;
	}
	}

	//check whether there is any credit
	if (processCredit == 0)
	return;


	//check whether sent queue empty
	if (nextSegmentQueue.empty()) {
	//do not do anything
	return;
	}

	//pop the queue
	SegmentNo sendingSegment = nextSegmentQueue.front();
	nextSegmentQueue.pop();

	//check whether sendingSegment exceeds
	if (response.hasEndBlockId() && sendingSegment > response.getEndBlockId()) {
	//do not do anything
	return;
	}

	//read whether this is retransmitted data;
	SegmentNo fetchedSegment =
	interest.getName().get(interest.getName().size() - 1).toSegment();

	BOOST_ASSERT(retryCounts.count(fetchedSegment) != 0);

	//find this fetched data, remove it from this map
	//rit->second.erase(oit);
	retryCounts.erase(fetchedSegment);
	//express the interest of the top of the queue
	Name fetchName(interest.getName().getPrefix(-1));
	fetchName.appendSegment(sendingSegment);
	Interest fetchInterest(fetchName);
	fetchInterest.setInterestLifetime(m_interestLifetime);
	getFace().expressInterest(fetchInterest,
	bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
	//When an interest is expressed, processCredit--
	processCredit--;
	if (retryCounts.count(sendingSegment) == 0) {
	//not found
	retryCounts[sendingSegment] = 0;
	}
	else {
	//found
	retryCounts[sendingSegment] = retryCounts[sendingSegment] + 1;
	}
	//increase the next seg and put it into the queue
	if (!response.hasEndBlockId() \|\| (nextSegment + 1) <= response.getEndBlockId()) {
	nextSegment++;
	nextSegmentQueue.push(nextSegment);
	}
	}

	void
	WriteHandle::onSegmentTimeoutControl(ProcessId processId, const Interest& interest)
	{
	if (m_processes.count(processId) == 0) {
	return;
	}
	ProcessInfo& process = m_processes[processId];
	// RepoCommandResponse& response = process.response;
	// SegmentNo& nextSegment = process.nextSegment;
	// queue<SegmentNo>& nextSegmentQueue = process.nextSegmentQueue;
	map<SegmentNo, int>& retryCounts = process.retryCounts;

	SegmentNo timeoutSegment = interest.getName().get(-1).toSegment();

	std::cerr << "timeoutSegment: " << timeoutSegment << std::endl;

	BOOST_ASSERT(retryCounts.count(timeoutSegment) != 0);

	//read the retry time. If retry out of time, fail the process. if not, plus
	int& retryTime = retryCounts[timeoutSegment];
	if (retryTime >= m_retryTime) {
	//fail this process
	std::cerr << "Retry timeout: " << processId << std::endl;
	m_processes.erase(processId);
	return;
	}
	else {
	//Reput it in the queue, retryTime++
	retryTime++;
	Interest retryInterest(interest.getName());
	retryInterest.setInterestLifetime(m_interestLifetime);
	getFace().expressInterest(retryInterest,
	bind(&WriteHandle::onSegmentData, this, _1, _2, processId),
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId), // Nack
	bind(&WriteHandle::onSegmentTimeout, this, _1, processId));
	}

	}

	void
	WriteHandle::onCheckInterest(const Name& prefix, const Interest& interest)
	{
	m_validator.validate(interest,
	bind(&WriteHandle::onCheckValidated, this, _1, prefix),
	bind(&WriteHandle::onCheckValidationFailed, this, _1, _2));

	}

	void
	WriteHandle::onCheckValidated(const Interest& interest, const Name& prefix)
	{
	RepoCommandParameter parameter;
	try {
	extractParameter(interest, prefix, parameter);
	}
	catch (const RepoCommandParameter::Error&) {
	negativeReply(interest, 403);
	return;
	}

	if (!parameter.hasProcessId()) {
	negativeReply(interest, 403);
	return;
	}
	//check whether this process exists
	ProcessId processId = parameter.getProcessId();
	if (m_processes.count(processId) == 0) {
	std::cerr << "no such processId: " << processId << std::endl;
	negativeReply(interest, 404);
	return;
	}

	ProcessInfo& process = m_processes[processId];

	RepoCommandResponse& response = process.response;

	//Check whether it is single data fetching
	if (!response.hasStartBlockId() &&
	!response.hasEndBlockId()) {
	reply(interest, response);
	return;
	}

	//read if noEndtimeout
	if (!response.hasEndBlockId()) {
	extendNoEndTime(process);
	reply(interest, response);
	return;
	}
	else {
	reply(interest, response);
	}
	}

	void
	WriteHandle::onCheckValidationFailed(const Interest& interest, const ValidationError& error)
	{
	std::cerr << error << std::endl;
	negativeReply(interest, 401);
	}

	void
	WriteHandle::deferredDeleteProcess(ProcessId processId)
	{
	getScheduler().scheduleEvent(PROCESS_DELETE_TIME,
	bind(&WriteHandle::deleteProcess, this, processId));
	}

	void
	WriteHandle::processSingleInsertCommand(const Interest& interest,
	RepoCommandParameter& parameter)
	{
	ProcessId processId = generateProcessId();

	ProcessInfo& process = m_processes[processId];

	RepoCommandResponse& response = process.response;
	response.setStatusCode(100);
	response.setProcessId(processId);
	response.setInsertNum(0);

	reply(interest, response);

	response.setStatusCode(300);

	Interest fetchInterest(parameter.getName());
	fetchInterest.setInterestLifetime(m_interestLifetime);
	if (parameter.hasSelectors()) {
	fetchInterest.setSelectors(parameter.getSelectors());
	}
	getFace().expressInterest(fetchInterest,
	bind(&WriteHandle::onData, this, _1, _2, processId),
	bind(&WriteHandle::onTimeout, this, _1, processId), // Nack
	bind(&WriteHandle::onTimeout, this, _1, processId));
	}

	void
	WriteHandle::processSegmentedInsertCommand(const Interest& interest,
	RepoCommandParameter& parameter)
	{
	if (parameter.hasEndBlockId()) {
	//normal fetch segment
	if (!parameter.hasStartBlockId()) {
	parameter.setStartBlockId(0);
	}

	SegmentNo startBlockId = parameter.getStartBlockId();
	SegmentNo endBlockId = parameter.getEndBlockId();
	if (startBlockId > endBlockId) {
	negativeReply(interest, 403);
	return;
	}

	ProcessId processId = generateProcessId();
	ProcessInfo& process = m_processes[processId];
	RepoCommandResponse& response = process.response;
	response.setStatusCode(100);
	response.setProcessId(processId);
	response.setInsertNum(0);
	response.setStartBlockId(startBlockId);
	response.setEndBlockId(endBlockId);

	reply(interest, response);

	//300 means data fetching is in progress
	response.setStatusCode(300);

	segInit(processId, parameter);
	}
	else {
	//no EndBlockId, so fetch FinalBlockId in data, if timeout, stop
	ProcessId processId = generateProcessId();
	ProcessInfo& process = m_processes[processId];
	RepoCommandResponse& response = process.response;
	response.setStatusCode(100);
	response.setProcessId(processId);
	response.setInsertNum(0);
	response.setStartBlockId(parameter.getStartBlockId());
	reply(interest, response);

	//300 means data fetching is in progress
	response.setStatusCode(300);

	segInit(processId, parameter);
	}
	}

	void
	WriteHandle::extendNoEndTime(ProcessInfo& process)
	{
	ndn::time::steady_clock::TimePoint& noEndTime = process.noEndTime;
	ndn::time::steady_clock::TimePoint now = ndn::time::steady_clock::now();
	RepoCommandResponse& response = process.response;
	if (now > noEndTime) {
	response.setStatusCode(405);
	return;
	}
	//extends noEndTime
	process.noEndTime =
	ndn::time::steady_clock::now() + m_noEndTimeout;

	}

	void
	WriteHandle::negativeReply(const Interest& interest, int statusCode)
	{
	RepoCommandResponse response;
	response.setStatusCode(statusCode);
	reply(interest, response);
	}

	} // namespace repo