def __init__(self, nodeA, nodeB, rate, delay, maxbuffersize, linkid):
""" Create a Link
:param nodeA: Node that it is connected to (object)
:param nodeB: Node that it is connected to (object)
:param rate: rate (mbps) that this Link can send
:param delay: time (ms) for a packet to propagate
:param maxbuffersize: maximum buffer size (combined for both sides) (KB)
:param linkid: id of the Link
"""
self.nodeA = nodeA
self.nodeB = nodeB
self.rate = rate
self.delay = delay
self.maxbuffersize = maxbuffersize * 1024
self.id = linkid
self.buffer = Queue() # Queue using a cyclic array
self.totalbuffersize = 0 # total size of items in the buffer, bytes
self.buffersizes = dict() # size of items in buffer for A, B in bytes
self.buffersizes[self.nodeA] = 0
self.buffersizes[self.nodeB] = 0
self.freeAt = -9999999 # Next time the Link is free
self.stats = LinkStats(self.id)
def __init__(self, nodeA, nodeB, rate, delay, maxbuffersize, linkid):
""" Create a Link
:param nodeA: Node that it is connected to (object)
:param nodeB: Node that it is connected to (object)
:param rate: rate (mbps) that this Link can send
:param delay: time (ms) for a packet to propagate
:param maxbuffersize: maximum buffer size (combined for both sides) (KB)
:param linkid: id of the Link
"""
self.nodeA = nodeA
self.nodeB = nodeB
self.rate = rate
self.delay = delay
self.maxbuffersize = maxbuffersize * 1024
self.id = linkid
self.buffer = Queue() # Queue using a cyclic array
self.totalbuffersize = 0 # total size of items in the buffer, bytes
self.buffersizes = dict() # size of items in buffer for A, B in bytes
self.buffersizes[self.nodeA] = 0
self.buffersizes[self.nodeB] = 0
self.freeAt = -9999999 # Next time the Link is free
self.stats = LinkStats(self.id)
class Link(NetworkObject):
""" Represents link in a network
This class represents a link in a network that packets can travel
across"""
def __init__(self, nodeA, nodeB, rate, delay, maxbuffersize, linkid):
""" Create a Link
:param nodeA: Node that it is connected to (object)
:param nodeB: Node that it is connected to (object)
:param rate: rate (mbps) that this Link can send
:param delay: time (ms) for a packet to propagate
:param maxbuffersize: maximum buffer size (combined for both sides) (KB)
:param linkid: id of the Link
"""
self.nodeA = nodeA
self.nodeB = nodeB
self.rate = rate
self.delay = delay
self.maxbuffersize = maxbuffersize * 1024
self.id = linkid
self.buffer = Queue() # Queue using a cyclic array
self.totalbuffersize = 0 # total size of items in the buffer, bytes
self.buffersizes = dict() # size of items in buffer for A, B in bytes
self.buffersizes[self.nodeA] = 0
self.buffersizes[self.nodeB] = 0
self.freeAt = -9999999 # Next time the Link is free
self.stats = LinkStats(self.id)
def addPackets(self, packets, sender):
""" Add packets and return new Events if any.
A shortcut for sending PacketEvents and so they do not go through
the EventHandler
:param packets: new packets to add
:return: new Events
"""
newevents = []
# If this is the first packet in the buffer, start the LinkTickEvents
if self.buffer.qsize() == 0 and len(packets) > 0:
newevents = [
LinkTickEvent(max(simtimer.simtime, self.freeAt), self,
'Link ' + self.id + ' processes a packet')
]
for p in packets:
if self.buffersizes[sender] + p.size > self.maxbuffersize:
# Drop em' like its hot
logger.log('Dropping packet %s from host %s at link %s' %
(p.index, p.source, self.id))
self.stats.addLostPackets(simtimer.simtime, 1)
else:
self.buffer.put((p, sender))
self.totalbuffersize += p.size
self.buffersizes[sender] += p.size
self.stats.updateBufferOccupancy(simtimer.simtime,
self.totalbuffersize)
return newevents
def _processPacketEvent(self, packet_event):
""" Processes packet events, storing them in the buffer.
:param packet_event: PacketEvent to process (packet to insert)
:return: new Events to enqueue
"""
packet, sender = packet_event.packet, packet_event.sender
if self.buffersizes[sender] + packet.size > self.maxbuffersize:
self.stats.addLostPackets(packet_event.timestamp, 1)
logger.log('Dropping packet %s from host %s at link %s' %
(packet.index, str(sender), self.id))
return []
self.buffer.put((packet, sender))
self.totalbuffersize += packet.size
self.buffersizes[sender] += packet.size
self.stats.updateBufferOccupancy(simtimer.simtime,
self.totalbuffersize)
# If this is the first packet in the buffer, start the LinkTickEvents
if self.buffer.qsize() == 1:
linkevent = LinkTickEvent(
max(packet_event.timestamp, self.freeAt), self,
'Link ' + self.id + ' processes a packet')
return [linkevent]
return []
def _linkTickEvent(self, event):
""" Dequeues a packet from the buffer and forwards it.
Also possibly generates a new LinkTickEvent if there are more packets
in the buffer.
:param event: LinkTickEvent to process
:return: new Events to enqueue
"""
packet, sender = self.buffer.get()
self.totalbuffersize -= packet.size
self.buffersizes[sender] -= packet.size
self.stats.updateBufferOccupancy(simtimer.simtime,
self.totalbuffersize)
# Generate a new PacketEvent
# Use event.timestamp because this is when the packet is actually
# forwarded, not the PacketEvent time
otherNode = self._otherNode(sender)
tick = 125.0 / 16384 * packet.size / self.rate # convert bytes to ms
type = 'ACK' if packet.ack else 'packet'
newevents = [
PacketEvent(
event.timestamp + self.delay + tick, self, otherNode, packet,
'Node %s receives %s %s from link %s' %
(otherNode.address, type, packet.index, self.id))
]
self.stats.addBytesFlowed(event.timestamp, packet.size)
# Make a new LinkTickEvent to time the next dequeue event
self.freeAt = event.timestamp + tick
if not self.buffer.empty():
newevents.append(
LinkTickEvent(self.freeAt, self,
'Link %s processes a packet' % self.id))
return newevents
def _processOtherEvent(self, event):
""" Processes non-packet events
:param event: Event to process
:return: new Events to enqueue
"""
if isinstance(event, LinkTickEvent):
return self._linkTickEvent(event)
else:
raise NotImplementedError('Handling of %s not implemented' %
event.__class__)
def _otherNode(self, node):
""" Returns the other node the link is connected to
:param node: nodeA or nodeB
:return: nodeB or nodeA (opposite of parameter node)
"""
return self.nodeB if node == self.nodeA else self.nodeA
def cost(self):
""" Return cost of going through the edge
:return: cost, in ms
"""
return self.delay + 125.0 / 16384 * self.totalbuffersize / self.rate
class Link(NetworkObject):
""" Represents link in a network
This class represents a link in a network that packets can travel
across"""
def __init__(self, nodeA, nodeB, rate, delay, maxbuffersize, linkid):
""" Create a Link
:param nodeA: Node that it is connected to (object)
:param nodeB: Node that it is connected to (object)
:param rate: rate (mbps) that this Link can send
:param delay: time (ms) for a packet to propagate
:param maxbuffersize: maximum buffer size (combined for both sides) (KB)
:param linkid: id of the Link
"""
self.nodeA = nodeA
self.nodeB = nodeB
self.rate = rate
self.delay = delay
self.maxbuffersize = maxbuffersize * 1024
self.id = linkid
self.buffer = Queue() # Queue using a cyclic array
self.totalbuffersize = 0 # total size of items in the buffer, bytes
self.buffersizes = dict() # size of items in buffer for A, B in bytes
self.buffersizes[self.nodeA] = 0
self.buffersizes[self.nodeB] = 0
self.freeAt = -9999999 # Next time the Link is free
self.stats = LinkStats(self.id)
def addPackets(self, packets, sender):
""" Add packets and return new Events if any.
A shortcut for sending PacketEvents and so they do not go through
the EventHandler
:param packets: new packets to add
:return: new Events
"""
newevents = []
# If this is the first packet in the buffer, start the LinkTickEvents
if self.buffer.qsize() == 0 and len(packets) > 0:
newevents = [
LinkTickEvent(max(simtimer.simtime, self.freeAt), self,
'Link ' + self.id + ' processes a packet')]
for p in packets:
if self.buffersizes[sender] + p.size > self.maxbuffersize:
# Drop em' like its hot
logger.log('Dropping packet %s from host %s at link %s' %
(p.index, p.source, self.id))
self.stats.addLostPackets(simtimer.simtime, 1)
else:
self.buffer.put((p, sender))
self.totalbuffersize += p.size
self.buffersizes[sender] += p.size
self.stats.updateBufferOccupancy(simtimer.simtime, self.totalbuffersize)
return newevents
def _processPacketEvent(self, packet_event):
""" Processes packet events, storing them in the buffer.
:param packet_event: PacketEvent to process (packet to insert)
:return: new Events to enqueue
"""
packet, sender = packet_event.packet, packet_event.sender
if self.buffersizes[sender] + packet.size > self.maxbuffersize:
self.stats.addLostPackets(packet_event.timestamp, 1)
logger.log('Dropping packet %s from host %s at link %s' %
(packet.index, str(sender), self.id))
return []
self.buffer.put((packet, sender))
self.totalbuffersize += packet.size
self.buffersizes[sender] += packet.size
self.stats.updateBufferOccupancy(simtimer.simtime, self.totalbuffersize)
# If this is the first packet in the buffer, start the LinkTickEvents
if self.buffer.qsize() == 1:
linkevent = LinkTickEvent(max(packet_event.timestamp, self.freeAt),
self, 'Link ' + self.id + ' processes a packet')
return [linkevent]
return []
def _linkTickEvent(self, event):
""" Dequeues a packet from the buffer and forwards it.
Also possibly generates a new LinkTickEvent if there are more packets
in the buffer.
:param event: LinkTickEvent to process
:return: new Events to enqueue
"""
packet, sender = self.buffer.get()
self.totalbuffersize -= packet.size
self.buffersizes[sender] -= packet.size
self.stats.updateBufferOccupancy(simtimer.simtime, self.totalbuffersize)
# Generate a new PacketEvent
# Use event.timestamp because this is when the packet is actually
# forwarded, not the PacketEvent time
otherNode = self._otherNode(sender)
tick = 125.0 / 16384 * packet.size / self.rate # convert bytes to ms
type = 'ACK' if packet.ack else 'packet'
newevents = [
PacketEvent(event.timestamp + self.delay + tick,
self, otherNode, packet,
'Node %s receives %s %s from link %s' %
(otherNode.address, type, packet.index, self.id))]
self.stats.addBytesFlowed(event.timestamp, packet.size)
# Make a new LinkTickEvent to time the next dequeue event
self.freeAt = event.timestamp + tick
if not self.buffer.empty():
newevents.append(
LinkTickEvent(self.freeAt, self,
'Link %s processes a packet' % self.id))
return newevents
def _processOtherEvent(self, event):
""" Processes non-packet events
:param event: Event to process
:return: new Events to enqueue
"""
if isinstance(event, LinkTickEvent):
return self._linkTickEvent(event)
else:
raise NotImplementedError(
'Handling of %s not implemented' % event.__class__)
def _otherNode(self, node):
""" Returns the other node the link is connected to
:param node: nodeA or nodeB
:return: nodeB or nodeA (opposite of parameter node)
"""
return self.nodeB if node == self.nodeA else self.nodeA
def cost(self):
""" Return cost of going through the edge
:return: cost, in ms
"""
return self.delay + 125.0 / 16384 * self.totalbuffersize / self.rate