from device import Device
[docs]class Host(Device):
"""Simple class for hosts.
Hosts are mainly responsible for recording their time data.
They don't trigger events in the simulation, but it will be
useful to separate host data (end to end data). Flows
will trigger host behavior.
Parameters
----------
host_id : string
A unique id for the host.
Attributes
----------
network_id : string
A unique id of the device in the network.
links : list
A list of links that the host is connected to.
flows : list
A list of flows that use the host.
Methods
-------
add_flow(flow)
Adds receiving flow to host.
delete_flow(flow)
Delete flow from the host.
send(packet)
Sends a packet to a link.
receive(packet)
Receives a packet from a link.
"""
def __init__(self, host_id):
"""Constructor for Host class."""
super(Host, self).__init__(host_id)
self._flows = []
@property
def flows(self):
return self._flows
[docs] def add_flow(self, flow):
"""Add receiving flow to host.
Parameters
----------
flow : `Flow`
The flow to add to the host.
"""
self._flows.append(flow)
[docs] def delete_flow(self, flow):
"""Delete flow from host.
Parameters
----------
flow : `Flow`
The flow to add to the host.
"""
self._flows.remove(flow)
[docs] def send(self, packet):
"""Connects to a link.
Parameters
----------
packet : `Packet`
The packet to send.
"""
if len(self._links) > 0:
self._links[0].receive(packet, self._network_id)
else:
raise Exception("Host {0} does not have any"
" links".format(self.network_id))
[docs] def receive(self, packet):
"""Send packet to flow to process.
Parameters
----------
packet : `Packet`
The packet to be received.
"""
for flow in self._flows:
if packet.flow_id == flow.flow_id:
flow.receive(packet)
return