Files
unison/src/network/helper/delay-jitter-estimation.cc
2018-10-19 00:03:07 -04:00

155 lines
3.9 KiB
C++

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2007 INRIA
*
* 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
*
* Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
*/
#include "delay-jitter-estimation.h"
#include "ns3/tag.h"
#include "ns3/simulator.h"
#include "ns3/string.h"
namespace ns3 {
/**
* Tag to perform Delay and Jitter estimations
*
* The tag holds the packet's creation timestamp
*/
class DelayJitterEstimationTimestampTag : public Tag
{
public:
DelayJitterEstimationTimestampTag ();
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
virtual TypeId GetInstanceTypeId (void) const;
virtual uint32_t GetSerializedSize (void) const;
virtual void Serialize (TagBuffer i) const;
virtual void Deserialize (TagBuffer i);
virtual void Print (std::ostream &os) const;
/**
* \brief Get the Transmission time stored in the tag
* \return the transmission time
*/
Time GetTxTime (void) const;
private:
uint64_t m_creationTime; //!< The time stored in the tag
};
DelayJitterEstimationTimestampTag::DelayJitterEstimationTimestampTag ()
: m_creationTime (Simulator::Now ().GetTimeStep ())
{
}
TypeId
DelayJitterEstimationTimestampTag::GetTypeId (void)
{
static TypeId tid = TypeId ("anon::DelayJitterEstimationTimestampTag")
.SetParent<Tag> ()
.SetGroupName("Network")
.AddConstructor<DelayJitterEstimationTimestampTag> ()
.AddAttribute ("CreationTime",
"The time at which the timestamp was created",
StringValue ("0.0s"),
MakeTimeAccessor (&DelayJitterEstimationTimestampTag::GetTxTime),
MakeTimeChecker ())
;
return tid;
}
TypeId
DelayJitterEstimationTimestampTag::GetInstanceTypeId (void) const
{
return GetTypeId ();
}
uint32_t
DelayJitterEstimationTimestampTag::GetSerializedSize (void) const
{
return 8;
}
void
DelayJitterEstimationTimestampTag::Serialize (TagBuffer i) const
{
i.WriteU64 (m_creationTime);
}
void
DelayJitterEstimationTimestampTag::Deserialize (TagBuffer i)
{
m_creationTime = i.ReadU64 ();
}
void
DelayJitterEstimationTimestampTag::Print (std::ostream &os) const
{
os << "CreationTime=" << m_creationTime;
}
Time
DelayJitterEstimationTimestampTag::GetTxTime (void) const
{
return TimeStep (m_creationTime);
}
DelayJitterEstimation::DelayJitterEstimation ()
: m_previousRx (Simulator::Now ()),
m_previousRxTx (Simulator::Now ()),
m_jitter (0),
m_delay (Seconds (0.0))
{
}
void
DelayJitterEstimation::PrepareTx (Ptr<const Packet> packet)
{
DelayJitterEstimationTimestampTag tag;
packet->AddByteTag (tag);
}
void
DelayJitterEstimation::RecordRx (Ptr<const Packet> packet)
{
DelayJitterEstimationTimestampTag tag;
bool found;
found = packet->FindFirstMatchingByteTag (tag);
if (!found)
{
return;
}
tag.GetTxTime ();
Time delta = (Simulator::Now () - m_previousRx) - (tag.GetTxTime () - m_previousRxTx);
m_jitter += (Abs (delta) - m_jitter) / (int64x64_t)16;
m_previousRx = Simulator::Now ();
m_previousRxTx = tag.GetTxTime ();
m_delay = Simulator::Now () - tag.GetTxTime ();
}
Time
DelayJitterEstimation::GetLastDelay (void) const
{
return m_delay;
}
uint64_t
DelayJitterEstimation::GetLastJitter (void) const
{
return m_jitter.GetHigh ();
}
} // namespace ns3