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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2019 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx library is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* ndn-cxx library 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 Lesser General Public License for more details.
*
* You should have received copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*/
#ifndef NDN_IMPL_PENDING_INTEREST_HPP
#define NDN_IMPL_PENDING_INTEREST_HPP
#include "ndn-cxx/data.hpp"
#include "ndn-cxx/face.hpp"
#include "ndn-cxx/interest.hpp"
#include "ndn-cxx/lp/nack.hpp"
#include "ndn-cxx/util/scheduler.hpp"
namespace ndn {
/**
* @brief Indicates where a pending Interest came from
*/
enum class PendingInterestOrigin
{
APP, ///< Interest was received from this app via Face::expressInterest API
FORWARDER ///< Interest was received from the forwarder via Transport
};
std::ostream&
operator<<(std::ostream& os, PendingInterestOrigin origin)
{
switch (origin) {
case PendingInterestOrigin::APP:
return os << "app";
case PendingInterestOrigin::FORWARDER:
return os << "forwarder";
}
BOOST_ASSERT(false);
return os;
}
/**
* @brief Stores a pending Interest and associated callbacks
*/
class PendingInterest : noncopyable
{
public:
/**
* @brief Construct a pending Interest record for an Interest from Face::expressInterest
*
* The timeout is set based on the current time and InterestLifetime.
* This class will invoke the timeout callback unless the record is deleted before timeout.
*
* @param interest the Interest
* @param dataCallback invoked when matching Data packet is received
* @param nackCallback invoked when Nack matching Interest is received
* @param timeoutCallback invoked when Interest times out
* @param scheduler Scheduler for scheduling the timeout event
*/
PendingInterest(shared_ptr<const Interest> interest,
const DataCallback& dataCallback,
const NackCallback& nackCallback,
const TimeoutCallback& timeoutCallback,
Scheduler& scheduler)
: m_interest(std::move(interest))
, m_origin(PendingInterestOrigin::APP)
, m_dataCallback(dataCallback)
, m_nackCallback(nackCallback)
, m_timeoutCallback(timeoutCallback)
, m_nNotNacked(0)
{
scheduleTimeoutEvent(scheduler);
}
/**
* @brief Construct a pending Interest record for an Interest from NFD
*
* @param interest the Interest
* @param scheduler Scheduler for scheduling the timeout event
*/
PendingInterest(shared_ptr<const Interest> interest, Scheduler& scheduler)
: m_interest(std::move(interest))
, m_origin(PendingInterestOrigin::FORWARDER)
, m_nNotNacked(0)
{
scheduleTimeoutEvent(scheduler);
}
/**
* @brief Get the Interest
*/
shared_ptr<const Interest>
getInterest() const
{
return m_interest;
}
PendingInterestOrigin
getOrigin() const
{
return m_origin;
}
/**
* @brief Record that the Interest has been forwarded to one destination
*
* A "destination" could be either a local InterestFilter or the forwarder.
*/
void
recordForwarding()
{
++m_nNotNacked;
}
/**
* @brief Record an incoming Nack against a forwarded Interest
* @return least severe Nack if all destinations where the Interest was forwarded have Nacked;
* otherwise, nullopt
*/
optional<lp::Nack>
recordNack(const lp::Nack& nack)
{
--m_nNotNacked;
BOOST_ASSERT(m_nNotNacked >= 0);
if (!m_leastSevereNack || lp::isLessSevere(nack.getReason(), m_leastSevereNack->getReason())) {
m_leastSevereNack = nack;
}
return m_nNotNacked > 0 ? nullopt : m_leastSevereNack;
}
/**
* @brief Invoke the Data callback
* @note This method does nothing if the Data callback is empty
*/
void
invokeDataCallback(const Data& data)
{
if (m_dataCallback != nullptr) {
m_dataCallback(*m_interest, data);
}
}
/**
* @brief Invoke the Nack callback
* @note This method does nothing if the Nack callback is empty
*/
void
invokeNackCallback(const lp::Nack& nack)
{
if (m_nackCallback != nullptr) {
m_nackCallback(*m_interest, nack);
}
}
/**
* @brief Set cleanup function to be invoked when Interest times out
*/
void
setDeleter(const std::function<void()>& deleter)
{
m_deleter = deleter;
}
private:
void
scheduleTimeoutEvent(Scheduler& scheduler)
{
m_timeoutEvent = scheduler.scheduleEvent(m_interest->getInterestLifetime(),
[=] { this->invokeTimeoutCallback(); });
}
/**
* @brief Invoke the timeout callback (if non-empty) and the deleter
*/
void
invokeTimeoutCallback()
{
if (m_timeoutCallback) {
m_timeoutCallback(*m_interest);
}
BOOST_ASSERT(m_deleter);
m_deleter();
}
private:
shared_ptr<const Interest> m_interest;
PendingInterestOrigin m_origin;
DataCallback m_dataCallback;
NackCallback m_nackCallback;
TimeoutCallback m_timeoutCallback;
util::scheduler::ScopedEventId m_timeoutEvent;
int m_nNotNacked; ///< number of Interest destinations that have not Nacked
optional<lp::Nack> m_leastSevereNack;
std::function<void()> m_deleter;
};
/**
* @brief Opaque type to identify a PendingInterest
*/
class PendingInterestId;
/**
* @brief Functor to match PendingInterestId
*/
class MatchPendingInterestId
{
public:
explicit
MatchPendingInterestId(const PendingInterestId* pendingInterestId)
: m_id(pendingInterestId)
{
}
bool
operator()(const shared_ptr<const PendingInterest>& pendingInterest) const
{
return reinterpret_cast<const PendingInterestId*>(pendingInterest->getInterest().get()) == m_id;
}
private:
const PendingInterestId* m_id;
};
} // namespace ndn
#endif // NDN_IMPL_PENDING_INTEREST_HPP