class Network:
""" A network control singleton object. """
__instance = None
@staticmethod
def get_instance():
if Network.__instance is None:
Network()
return Network.__instance
@staticmethod
def reset_network():
if Network.__instance is not None:
Network.__instance.stop(True)
Network.__instance = None
__instance = Network()
def __init__(self):
if Network.__instance is None:
self.ARP = {}
# The directed graph for the connections
self.classical_network = nx.DiGraph()
self.quantum_network = nx.DiGraph()
self._quantum_routing_algo = nx.shortest_path
self._classical_routing_algo = nx.shortest_path
self._use_hop_by_hop = True
self._packet_queue = Queue()
self._stop_thread = False
self._use_ent_swap = False
self._queue_processor_thread = None
self._delay = 0.1
self._packet_drop_rate = 0
self._backend = None
Network.__instance = self
else:
raise Exception('this is a singleton class')
@property
def use_ent_swap(self):
return self._use_ent_swap
@use_ent_swap.setter
def use_ent_swap(self, use_ent_swap):
self._use_ent_swap = use_ent_swap
@property
def use_hop_by_hop(self):
"""
Get the routing style for the network.
Returns:
If the network uses hop by hop routing.
"""
return self._use_hop_by_hop
@use_hop_by_hop.setter
def use_hop_by_hop(self, should_use):
"""
Set the routing style for the network.
Args:
should_use (bool): If the network should use hop by hop routing or not
"""
if not isinstance(should_use, bool):
raise Exception('use_hop_by_hop should be a boolean value.')
self._use_hop_by_hop = should_use
@property
def classical_routing_algo(self):
"""
Get the routing algorithm for the network.
"""
return self._classical_routing_algo
@classical_routing_algo.setter
def classical_routing_algo(self, algorithm):
"""
Set the routing algorithm for the network.
Args:
algorithm (function): The routing function. Should return a list of host_ids which represents the route
"""
self._classical_routing_algo = algorithm
@property
def quantum_routing_algo(self):
"""
Gets the quantum routing algorithm of the network.
Returns:
algorithm (function): The quantum routing algorithm of the network
"""
return self._quantum_routing_algo
@quantum_routing_algo.setter
def quantum_routing_algo(self, algorithm):
"""
Sets the quantum routing algorithm of the network.
Args:
algorithm (function): The routing algorithm of the network. Should take an input and an output
"""
if not callable(algorithm):
raise Exception(
"The quantum routing algorithm must be a function.")
num_algo_params = len(signature(algorithm).parameters)
if num_algo_params != 3:
raise Exception(
"The quantum routing algorithm function should take three parameters: "
+
"the (nx) graph representation of the network, the sender address and the "
+ "receiver address.")
self._quantum_routing_algo = algorithm
@property
def delay(self):
"""
Get the delay interval of the network.
"""
return self._delay
@delay.setter
def delay(self, delay):
"""
Set the delay interval of the network.
Args:
delay (float): Delay in network tick in seconds
"""
if not (isinstance(delay, int) or isinstance(delay, float)):
raise Exception('delay should be a number')
if delay < 0:
raise Exception('Delay should not be negative')
self._delay = delay
@property
def packet_drop_rate(self):
"""
Get the drop rate of the network.
"""
return self._packet_drop_rate
@packet_drop_rate.setter
def packet_drop_rate(self, drop_rate):
"""
Set the drop rate of the network.
Args:
drop_rate (float): Probability of dropping a packet in the network
"""
if drop_rate < 0 or drop_rate > 1:
raise Exception('Packet drop rate should be between 0 and 1')
if not (isinstance(drop_rate, int) or isinstance(drop_rate, float)):
raise Exception('Packet drop rate should be a number')
self._packet_drop_rate = drop_rate
@property
def arp(self):
return self.ARP
@property
def num_hosts(self):
return len(self.arp.keys())
def add_host(self, host):
"""
Adds the *host* to ARP table and updates the network graph.
Args:
host (Host): The host to be added to the network.
"""
Logger.get_instance().debug('host added: ' + host.host_id)
self.ARP[host.host_id] = host
self._update_network_graph(host)
def add_hosts(self, hosts):
"""
Adds the *hosts* to ARP table and updates the network graph.
Args:
hosts (list): The hosts to be added to the network.
"""
for host in hosts:
self.add_host(host)
def remove_host(self, host):
"""
Removes the host from the network.
Args:
host (Host): The host to be removed from the network.
"""
if host.host_id in self.ARP:
del self.ARP[host.host_id]
if self.quantum_network.has_node(host.host_id):
self.quantum_network.remove_node(host.host_id)
if self.classical_network.has_node(host.host_id):
self.classical_network.remove_node(host.host_id)
def remove_c_connection(self, sender, receiver):
if self.classical_network.has_edge(sender, receiver):
self.classical_network.remove_edge(sender, receiver)
def remove_q_connection(self, sender, receiver):
if self.quantum_network.has_edge(sender, receiver):
self.quantum_network.remove_edge(sender, receiver)
def remove_hosts(self, hosts):
for host in hosts:
self.remove_host(host)
def update_host(self, host):
"""
Update the connections of a host in the network.
Args:
host:
Returns:
"""
self.remove_host(host)
self.add_host(host)
def _remove_network_node(self, host):
"""
Removes the host from the ARP table.
Args:
host (Host): The host to be removed from the network.
"""
try:
self.classical_network.remove_node(host.host_id)
except nx.NetworkXError:
Logger.get_instance().error(
'attempted to remove a non-exiting node from network')
def _update_network_graph(self, host):
"""
Add host *host* to the network and update the graph representation of the network
Args:
host: The host to be added
"""
if not self.classical_network.has_node(host.host_id):
self.classical_network.add_node(host.host_id)
if not self.quantum_network.has_node(host.host_id):
self.quantum_network.add_node(host.host_id)
for connection in host.classical_connections:
if not self.classical_network.has_edge(host.host_id, connection):
edge = (host.host_id, connection, {'weight': 1})
self.classical_network.add_edges_from([edge])
for connection in host.quantum_connections:
if not self.quantum_network.has_edge(host.host_id, connection):
edge = (host.host_id, connection, {'weight': 1})
self.quantum_network.add_edges_from([edge])
def shares_epr(self, sender, receiver):
"""
Returns boolean value dependent on if the sender and receiver share an EPR pair.
Args:
receiver (Host): The receiver
sender (Host): The sender
Returns:
(bool) whether the sender and receiver share an EPR pair.
"""
host_sender = self.get_host(sender)
host_receiver = self.get_host(receiver)
return host_sender.shares_epr(receiver) and host_receiver.shares_epr(
sender)
def get_host(self, host_id):
"""
Returns the host with the *host_id*.
Args:
host_id (str): ID number of the host that is returned.
Returns:
Host (Host): Host with the *host_id*
"""
if host_id not in self.ARP:
return None
return self.ARP[host_id]
def get_ARP(self):
"""
Returns the ARP table.
Returns:
dict: The ARP table
"""
return self.ARP
def get_host_name(self, host_id):
"""
Args:
host_id (str): ID number of the host whose name is returned if it is in ARP table
Returns the name of the host with *host_id* if the host is in ARP table , otherwise returns None.
Returns:
dict or None: Name of the host
"""
if host_id not in self.ARP:
return None
return self.ARP[host_id].cqc.name
def get_quantum_route(self, source, dest):
"""
Gets the route for quantum information from source to destination.
Args:
source (str): ID of the source host
dest (str): ID of the destination host
Returns:
route (list): An ordered list of ID numbers on the shortest path from source to destination.
"""
return self.quantum_routing_algo(self.quantum_network, source, dest)
def get_classical_route(self, source, dest):
"""
Gets the route for classical information from source to destination.
Args:
source (str): ID of the source host
dest (str): ID of the destination host
Returns:
route (list): An ordered list of ID numbers on the shortest path from source to destination.
"""
return self.classical_routing_algo(self.classical_network, source,
dest)
def _entanglement_swap(self, sender, receiver, route, q_id, o_seq_num,
blocked):
"""
Performs a chain of entanglement swaps with the hosts between sender and receiver to create a shared EPR pair
between sender and receiver.
Args:
sender (Host): Sender of the EPR pair
receiver (Host): Receiver of the EPR pair
route (list): Route between the sender and receiver
q_id (str): Qubit ID of the sent EPR pair
o_seq_num (int): The original sequence number
blocked (bool): If the pair being distributed is blocked or not
"""
host_sender = self.get_host(sender)
def establish_epr(net, s, r):
if not net.shares_epr(s, r):
self.get_host(s).send_epr(r, q_id, await_ack=True)
else:
old_id = self.get_host(s).change_epr_qubit_id(r, q_id)
net.get_host(r).change_epr_qubit_id(route[i], q_id, old_id)
# Create EPR pairs on the route, where all EPR qubits have the id q_id
threads = []
for i in range(len(route) - 1):
threads.append(
DaemonThread(establish_epr,
args=(self, route[i], route[i + 1])))
for t in threads:
t.join()
for i in range(len(route) - 2):
host = self.get_host(route[i + 1])
q = host.get_epr(route[0], q_id, wait=10)
if q is None:
print("Host is %s" % host.host_id)
print("Search host is %s" % route[0])
print("Search id is %s" % q_id)
print("EPR storage is")
print(host.EPR_store)
Logger.get_instance().error('Entanglement swap failed')
return
data = {
'q': q,
'eq_id': q_id,
'node': sender,
'o_seq_num': o_seq_num,
'type': Constants.EPR
}
if route[i + 2] == route[-1]:
data = {
'q': q,
'eq_id': q_id,
'node': sender,
'ack': True,
'o_seq_num': o_seq_num,
'type': Constants.EPR
}
host.send_teleport(route[i + 2],
None,
await_ack=True,
payload=data,
generate_epr_if_none=False)
# Change in the storage that the EPR qubit is shared with the receiver
q2 = host_sender.get_epr(route[1], q_id=q_id)
host_sender.add_epr(receiver, q2, q_id, blocked)
Logger.get_instance().log(
'Entanglement swap was successful for pair with id ' + q_id +
' between ' + sender + ' and ' + receiver)
def _establish_epr(self, sender, receiver, q_id, o_seq_num, blocked):
"""
Instead doing an entanglement swap, for efficiency we establish EPR pairs
directly for simulation, if an entanglement swap would have been possible.
Args:
sender (Host): Sender of the EPR pair
receiver (Host): Receiver of the EPR pair
q_id (str): Qubit ID of the sent EPR pair
o_seq_num (int): The original sequence number
blocked (bool): If the pair being distributed is blocked or not
"""
host_sender = self.get_host(sender)
host_receiver = self.get_host(receiver)
q1 = Qubit(host_sender)
q2 = Qubit(host_sender)
q1.H()
q1.cnot(q2)
host_sender.add_epr(receiver, q1, q_id, blocked)
host_receiver.add_epr(sender, q2, q_id, blocked)
host_receiver.send_ack(sender, o_seq_num)
def _route_quantum_info(self, sender, receiver, qubits):
"""
Routes qubits from sender to receiver.
Args:
sender (Host): Sender of qubits
receiver (Host): Receiver qubits
qubits (List of Qubits): The qubits to be sent
"""
def transfer_qubits(r, s, original_sender=None):
for q in qubits:
# Modify the qubit according to error function of the model
qubit_id = q.id
q = self.ARP[s].quantum_connections[
self.ARP[r].host_id].model.qubit_func(q)
if q is None:
# Log failure of transmission if qubit is lost
Logger.get_instance().log(
'transfer qubits - transfer of qubit ' + qubit_id +
' failed')
return False
else:
Logger.get_instance().log(
'transfer qubits - sending qubit ' + q.id)
q.send_to(self.ARP[r].host_id)
Logger.get_instance().log('transfer qubits - received ' +
q.id)
# Unblock qubits in case they were blocked
q.blocked = False
if self.ARP[r].q_relay_sniffing:
self.ARP[r].q_relay_sniffing_fn(
original_sender, receiver, q)
return True
route = self.get_quantum_route(sender, receiver)
i = 0
while i < len(route) - 1:
Logger.get_instance().log('sending qubits from ' + route[i] +
' to ' + route[i + 1])
if not transfer_qubits(
route[i + 1], route[i], original_sender=route[0]):
return False
i += 1
return True
def _process_queue(self):
"""
Runs a thread for processing the packets in the packet queue.
"""
while True:
packet = self._packet_queue.get()
if not packet:
# Stop the network
self._stop_thread = True
break
# Artificially delay the network
if self.delay > 0:
time.sleep(self.delay)
# Simulate packet loss
packet_drop_var = random.random()
if packet_drop_var > (1 - self.packet_drop_rate):
Logger.get_instance().log("PACKET DROPPED")
if packet.payload_type == Constants.QUANTUM:
packet.payload.release()
continue
sender, receiver = packet.sender, packet.receiver
if packet.payload_type == Constants.QUANTUM:
if not self._route_quantum_info(sender, receiver,
[packet.payload]):
continue
try:
if packet.protocol == Constants.RELAY and not self.use_hop_by_hop:
full_route = packet.route
route = full_route[full_route.index(sender):]
else:
if packet.protocol == Constants.REC_EPR:
route = self.get_classical_route(sender, receiver)
else:
route = self.get_classical_route(sender, receiver)
if len(route) < 2:
raise Exception('No route exists')
elif len(route) == 2:
if packet.protocol != Constants.RELAY:
if packet.protocol == Constants.REC_EPR:
host_sender = self.get_host(sender)
q = host_sender \
.backend \
.create_EPR(host_sender.host_id,
receiver,
q_id=packet.payload['q_id'],
block=packet.payload['blocked'])
host_sender.add_epr(receiver, q)
self.ARP[receiver].rec_packet(packet)
else:
self.ARP[receiver].rec_packet(packet.payload)
else:
if packet.protocol == Constants.REC_EPR:
q_id = packet.payload['q_id']
blocked = packet.payload['blocked']
q_route = self.get_quantum_route(sender, receiver)
if self.use_ent_swap:
DaemonThread(self._entanglement_swap,
args=(sender, receiver, q_route, q_id,
packet.seq_num, blocked))
else:
DaemonThread(self._establish_epr,
args=(sender, receiver, q_id,
packet.seq_num, blocked))
else:
network_packet = self._encode(route, packet)
self.ARP[route[1]].rec_packet(network_packet)
except nx.NodeNotFound:
Logger.get_instance().error(
"route couldn't be calculated, node doesn't exist")
except ValueError:
Logger.get_instance().error(
"route couldn't be calculated, value error")
except Exception as e:
Logger.get_instance().error('Error in network: ' + str(e))
def send(self, packet):
"""
Puts the packet to the packet queue of the network.
Args:
packet (Packet): Packet to be sent
"""
self._packet_queue.put(packet)
def stop(self, stop_hosts=False):
"""
Stops the network.
"""
Logger.get_instance().log("Network stopped")
try:
if stop_hosts:
for host in self.ARP:
self.ARP[host].stop(release_qubits=True)
self.send(None) # Send None to queue to stop the queue
if self._backend is not None:
self._backend.stop()
except Exception as e:
Logger.get_instance().error(e)
def start(self, nodes=None, backend=None):
"""
Starts the network.
"""
if backend is None:
self._backend = EQSNBackend()
else:
self._backend = backend
if nodes is not None:
self._backend.start(nodes=nodes)
self._queue_processor_thread = DaemonThread(target=self._process_queue)
def draw_classical_network(self):
"""
Draws a plot of the network.
"""
nx.draw_networkx(self.classical_network,
pos=nx.spring_layout(self.classical_network),
with_labels=True)
plt.show()
def draw_quantum_network(self):
"""
Draws a plot of the network.
"""
nx.draw_networkx(self.quantum_network,
pos=nx.spring_layout(self.quantum_network),
with_labels=True)
plt.show()
def _encode(self, route, payload, ttl=10):
"""
Adds another layer to the packet if route length between sender and receiver is greater than 2. Sets the
protocol flag in this layer to RELAY and payload_type as SIGNAL and adds a variable
Time-To-Live information in this layer.
Args:
route: route of the packet from sender to receiver
payload (Object): Lower layers of the packet
ttl(int): Time-to-Live parameter
Returns:
RoutingPacket: Encoded RELAY packet
"""
if payload.protocol != Constants.RELAY:
packet = RoutingPacket(route[1], '', Constants.RELAY,
Constants.SIGNAL, payload, ttl, route)
else:
packet = payload
packet.sender = route[1]
if self.use_hop_by_hop:
packet.receiver = route[-1]
else:
packet.receiver = route[2]
return packet
@staticmethod
def _get_star_topology_graph(hosts):
return nx.star_graph(hosts)
@staticmethod
def _get_ring_topology_graph(hosts):
graph = nx.path_graph(hosts)
graph.add_edge(hosts[0], hosts[len(hosts) - 1])
return graph
@staticmethod
def _get_mesh_topology_graph(hosts):
return nx.complete_graph(hosts)
@staticmethod
def _get_linear_topology_graph(hosts):
return nx.path_graph(hosts)
@staticmethod
def _get_tree_topology_graph(hosts):
graph = nx.empty_graph(hosts)
for i in range(0, len(hosts)):
if 2 * i + 1 < len(hosts):
graph.add_edge(hosts[i], hosts[2 * i + 1])
if 2 * i + 2 < len(hosts):
graph.add_edge(hosts[i], hosts[2 * i + 2])
return graph
topologies = {
'mesh': lambda x: Network._get_mesh_topology_graph(x),
'ring': lambda x: Network._get_ring_topology_graph(x),
'star': lambda x: Network._get_star_topology_graph(x),
'linear': lambda x: Network._get_linear_topology_graph(x),
'tree': lambda x: Network._get_tree_topology_graph(x)
# TODO: add bus topology
}
@staticmethod
def _validate_topology_input(host_names, topology):
if len(host_names) < 2:
raise ValueError('insufficient hosts')
if topology not in Network.topologies.keys():
raise ValueError('topology not implemented')
def _simple_topology_generation(self, host_names, topology, function):
from qunetsim import Host
Network._validate_topology_input(host_names, topology)
graph = Network.topologies[topology](host_names)
for host_name in host_names:
if host_name not in self.ARP.keys():
self.add_host(Host(host_name))
for node, adj_list in graph.adjacency():
h = self.get_host(node)
function(h, adj_list.keys())
self.add_host(h)
h.start()
def generate_topology(self, host_names: list, topology: str = 'mesh') \
-> None:
"""
Adjusts a network that already exists by adding both classic and
quantum connections that fit the desired network topology. This method
either adds new nodes or adds connections to existing hosts within
the network.
The supported network topologies are mesh, star, ring, linear, and
tree.
Args:
host_names (list): The names for the new hosts.
topology (str) {'mesh', 'star', 'ring', 'linear', 'tree'}: The
network topology that will be created.
"""
self.generate_c_topology(host_names, topology)
self.generate_q_topology(host_names, topology)
def generate_q_topology(self, host_names: list, topology: str = 'mesh') \
-> None:
"""
Adjusts a network that already exists by adding quantum connections
that fit the desired network topology. This method either adds new
nodes or adds connections to existing hosts within the network.
The supported network topologies are mesh, star, ring, linear, and
tree.
Args:
host_names (list): The names for the new hosts.
topology (str) {'mesh', 'star', 'ring', 'linear', 'tree'}: The
network topology that will be created.
"""
def add_quantum(x, y):
return x.add_q_connections(y)
self._simple_topology_generation(host_names, topology, add_quantum)
def generate_c_topology(self, host_names: list, topology: str = 'mesh') \
-> None:
"""
Adjusts a network that already exists by adding quantum connections
that fit the desired network topology. This method either adds new
nodes or adds connections to existing hosts within the network.
The supported network topologies are mesh, star, ring, linear, and
tree.
Args:
host_names (list): The names for the new hosts.
topology (str) {'mesh', 'star', 'ring', 'linear', 'tree'}: The
network topology that will be created.
"""
def add_classic(x, y):
return x.add_c_connections(y)
self._simple_topology_generation(host_names, topology, add_classic)
class Network:
""" A network control singleton object. """
__instance = None
@staticmethod
def get_instance():
if Network.__instance is None:
Network()
return Network.__instance
def __init__(self):
if Network.__instance is None:
self.ARP = {}
# The directed graph for the connections
self.classical_network = nx.DiGraph()
self.quantum_network = nx.DiGraph()
self._quantum_routing_algo = nx.shortest_path
self._classical_routing_algo = nx.shortest_path
self._use_hop_by_hop = True
self._packet_queue = Queue()
self._stop_thread = False
self._use_ent_swap = False
self._queue_processor_thread = None
self._delay = 0.1
self._packet_drop_rate = 0
self._x_error_rate = 0
self._z_error_rate = 0
self._backend = None
self._tick = 0
self._tickspan = 1e-8 # 10 ns
Network.__instance = self
else:
raise Exception('this is a singleton class')
@property
def use_ent_swap(self):
return self._use_ent_swap
@use_ent_swap.setter
def use_ent_swap(self, use_ent_swap):
self._use_ent_swap = use_ent_swap
@property
def use_hop_by_hop(self):
"""
Get the routing style for the network.
Returns:
If the network uses hop by hop routing.
"""
return self._use_hop_by_hop
@use_hop_by_hop.setter
def use_hop_by_hop(self, should_use):
"""
Set the routing style for the network.
Args:
should_use (bool): If the network should use hop by hop routing or not
"""
if not isinstance(should_use, bool):
raise Exception('use_hop_by_hop should be a boolean value.')
self._use_hop_by_hop = should_use
@property
def classical_routing_algo(self):
"""
Get the routing algorithm for the network.
"""
return self._classical_routing_algo
@classical_routing_algo.setter
def classical_routing_algo(self, algorithm):
"""
Set the routing algorithm for the network.
Args:
algorithm (function): The routing function. Should return a list of host_ids which represents the route
"""
self._classical_routing_algo = algorithm
@property
def quantum_routing_algo(self):
"""
Gets the quantum routing algorithm of the network.
Returns:
algorithm (function): The quantum routing algorithm of the network
"""
return self._quantum_routing_algo
@quantum_routing_algo.setter
def quantum_routing_algo(self, algorithm):
"""
Sets the quantum routing algorithm of the network.
Args:
algorithm (function): The routing algorithm of the network. Should take an input and an output
"""
if not callable(algorithm):
raise Exception(
"The quantum routing algorithm must be a function.")
num_algo_params = len(signature(algorithm).parameters)
if num_algo_params != 3:
raise Exception(
"The quantum routing algorithm function should take three parameters: "
+
"the (nx) graph representation of the network, the sender address and the "
+ "receiver address.")
self._quantum_routing_algo = algorithm
@property
def delay(self):
"""
Get the delay interval of the network.
"""
return self._delay
@delay.setter
def delay(self, delay):
"""
Set the delay interval of the network.
Args:
delay (float): Delay in network tick in seconds
"""
if not (isinstance(delay, int) or isinstance(delay, float)):
raise Exception('delay should be a number')
if delay < 0:
raise Exception('Delay should not be negative')
self._delay = delay
@property
def packet_drop_rate(self):
"""
Get the drop rate of the network.
"""
return self._packet_drop_rate
@packet_drop_rate.setter
def packet_drop_rate(self, drop_rate):
"""
Set the drop rate of the network.
Args:
drop_rate (float): Probability of dropping a packet in the network
"""
if drop_rate < 0 or drop_rate > 1:
raise Exception('Packet drop rate should be between 0 and 1')
if not (isinstance(drop_rate, int) or isinstance(drop_rate, float)):
raise Exception('Packet drop rate should be a number')
self._packet_drop_rate = drop_rate
@property
def x_error_rate(self):
"""
Get the X error rate of the network.
Returns:
The *x_error_rate* of the network.
"""
return self._x_error_rate
@x_error_rate.setter
def x_error_rate(self, error_rate):
"""
Set the X error rate of the network.
Args:
error_rate (float): Probability of a X error during a qubit transmission in the network
"""
if error_rate < 0 or error_rate > 1:
raise Exception('Error rate should be between 0 and 1.')
if not (isinstance(error_rate, int) or isinstance(error_rate, float)):
raise Exception('X error rate should be a number')
self._x_error_rate = error_rate
@property
def z_error_rate(self):
"""
Get the Z error rate of the network.
Returns:
(float): The Z error rate of the network.
"""
return self._z_error_rate
@z_error_rate.setter
def z_error_rate(self, error_rate):
"""
Set the Z error rate of the network.
Args:
error_rate (float): Probability of a Z error during a qubit transmission in the network
"""
if error_rate < 0 or error_rate > 1:
raise Exception('Error rate should be between 0 and 1.')
if not (isinstance(error_rate, int) or isinstance(error_rate, float)):
raise Exception('Z error rate should be a number')
self._z_error_rate = error_rate
@property
def tick(self):
"""
Returns the current tick of the network.
Used for timing operations.
Returns:
(int): Current tick of the network
"""
return self._tick
@property
def tickspan(self):
"""
Returns the real world time corresponding to one tick
Returns
(float): Span of real world time corresponding to a single tick
"""
return self._tickspan
@tickspan.setter
def tickspan(self, tickspan):
"""
Set the span of time corresponding to one network tick (defaults to 10 ns)
Args
tickspan (float): Span of real world time corresponding to a single tick
"""
if not (isinstance(tickspan, int) or isinstance(tickspan, float)):
raise Exception(
"Tickspan must be an integer or floating point number")
elif tickspan <= 0:
raise ValueError("Tickspan must be positive")
self._tickspan = tickspan
def add_host(self, host):
"""
Adds the *host* to ARP table and updates the network graph.
Args:
host (Host): The host to be added to the network.
"""
Logger.get_instance().debug('host added: ' + host.host_id)
self.ARP[host.host_id] = host
self._update_network_graph(host)
def add_hosts(self, hosts):
"""
Adds the *hosts* to ARP table and updates the network graph.
Args:
hosts (list): The hosts to be added to the network.
"""
for host in hosts:
self.add_host(host)
def remove_host(self, host):
"""
Removes the host from the ARP table.
Args:
host (Host): The host to be removed from the network.
"""
if host.host_id in self.ARP:
del self.ARP[host.host_id]
def update_host(self, host):
"""
Update the connections of a host in the network.
Args:
host:
Returns:
"""
self.remove_host(host)
self.add_host(host)
def _remove_network_node(self, host):
"""
Removes the host from the ARP table.
Args:
host (Host): The host to be removed from the network.
"""
try:
self.classical_network.remove_node(host.host_id)
except nx.NetworkXError:
Logger.get_instance().error(
'attempted to remove a non-exiting node from network')
def _update_network_graph(self, host):
"""
Add host *host* to the network and update the graph representation of the network
Args:
host: The host to be added
"""
self.classical_network.add_node(host.host_id)
self.quantum_network.add_node(host.host_id)
for connection in host.classical_connections:
if not self.classical_network.has_edge(host.host_id,
connection.receiver_id):
edge = (host.host_id, connection.receiver_id, {'weight': 1})
self.classical_network.add_edges_from([edge])
for connection in host.quantum_connections:
if not self.quantum_network.has_edge(host.host_id,
connection.receiver_id):
edge = (host.host_id, connection.receiver_id, {'weight': 1})
self.quantum_network.add_edges_from([edge])
def shares_epr(self, sender, receiver):
"""
Returns boolean value dependent on if the sender and receiver share an EPR pair.
Args:
receiver (Host): The receiver
sender (Host): The sender
Returns:
(bool) whether the sender and receiver share an EPR pair.
"""
host_sender = self.get_host(sender)
host_receiver = self.get_host(receiver)
return host_sender.shares_epr(receiver) and host_receiver.shares_epr(
sender)
def get_host(self, host_id):
"""
Returns the host with the *host_id*.
Args:
host_id (str): ID number of the host that is returned.
Returns:
Host (Host): Host with the *host_id*
"""
if host_id not in self.ARP:
return None
return self.ARP[host_id]
def get_ARP(self):
"""
Returns the ARP table.
Returns:
dict: The ARP table
"""
return self.ARP
def get_host_name(self, host_id):
"""
Args:
host_id (str): ID number of the host whose name is returned if it is in ARP table
Returns the name of the host with *host_id* if the host is in ARP table , otherwise returns None.
Returns:
dict or None: Name of the host
"""
if host_id not in self.ARP:
return None
return self.ARP[host_id].cqc.name
def get_quantum_route(self, source, dest):
"""
Gets the route for quantum information from source to destination.
Args:
source (str): ID of the source host
dest (str): ID of the destination host
Returns:
route (list): An ordered list of ID numbers on the shortest path from source to destination.
"""
return self.quantum_routing_algo(self.quantum_network, source, dest)
def get_classical_route(self, source, dest):
"""
Gets the route for classical information from source to destination.
Args:
source (str): ID of the source host
dest (str): ID of the destination host
Returns:
route (list): An ordered list of ID numbers on the shortest path from source to destination.
"""
return self.classical_routing_algo(self.classical_network, source,
dest)
def _entanglement_swap(self, sender, receiver, route, q_id, o_seq_num,
blocked):
"""
Performs a chain of entanglement swaps with the hosts between sender and receiver to create a shared EPR pair
between sender and receiver.
Args:
sender (Host): Sender of the EPR pair
receiver (Host): Receiver of the EPR pair
route (list): Route between the sender and receiver
q_id (str): Qubit ID of the sent EPR pair
o_seq_num (int): The original sequence number
blocked (bool): If the pair being distributed is blocked or not
"""
host_sender = self.get_host(sender)
lastfidelity = 1.0
def establish_epr(net, s, r):
if not net.shares_epr(s, r):
self.get_host(s).send_epr(r, q_id, await_ack=True)
else:
old_id = self.get_host(s).change_epr_qubit_id(r, q_id)
net.get_host(r).change_epr_qubit_id(route[i], q_id, old_id)
# Create EPR pairs on the route, where all EPR qubits have the id q_id
threads = []
for i in range(len(route) - 1):
threads.append(
DaemonThread(establish_epr,
args=(self, route[i], route[i + 1])))
for t in threads:
t.join()
for i in range(len(route) - 2):
host = self.get_host(route[i + 1])
q = host.get_epr(route[0], q_id, wait=10)
if q is None:
print("Host is %s" % host.host_id)
print("Search host is %s" % route[0])
print("Search id is %s" % q_id)
print("EPR storage is")
print(host.EPR_store)
Logger.get_instance().error('Entanglement swap failed')
return
data = {
'q': q,
'eq_id': q_id,
'node': sender,
'o_seq_num': o_seq_num,
'type': Constants.EPR
}
if route[i + 2] == route[-1]:
data = {
'q': q,
'eq_id': q_id,
'node': sender,
'ack': True,
'o_seq_num': o_seq_num,
'type': Constants.EPR
}
host.send_teleport(route[i + 2],
None,
await_ack=True,
payload=data,
generate_epr_if_none=False)
# Change in the storage that the EPR qubit is shared with the receiver
q2 = host_sender.get_epr(route[1], q_id=q_id)
host_sender.add_epr(receiver, q2, q_id, blocked)
Logger.get_instance().log(
'Entanglement swap was successful for pair with id ' + q_id +
' between ' + sender + ' and ' + receiver)
def _establish_epr(self, sender, receiver, q_id, o_seq_num, blocked):
"""
Instead doing an entanglement swap, for efficiency we establish EPR pairs
directly for simulation, if an entanglement swap would have been possible.
Args:
sender (Host): Sender of the EPR pair
receiver (Host): Receiver of the EPR pair
q_id (str): Qubit ID of the sent EPR pair
o_seq_num (int): The original sequence number
blocked (bool): If the pair being distributed is blocked or not
"""
host_sender = self.get_host(sender)
host_receiver = self.get_host(receiver)
q1 = Qubit(host_sender)
q2 = Qubit(host_sender)
q1.H()
q1.cnot(q2)
host_sender.add_epr(receiver, q1, q_id, blocked)
host_receiver.add_epr(sender, q2, q_id, blocked)
host_receiver.send_ack(sender, o_seq_num)
def _route_quantum_info(self, sender, receiver, qubits):
"""
Routes qubits from sender to receiver.
Args:
sender (Host): Sender of qubits
receiver (Host): Receiver qubits
qubits (List of Qubits): The qubits to be sent
"""
def transfer_qubits(r, original_sender=None):
for q in qubits:
Logger.get_instance().log('transfer qubits - sending qubit ' +
q.id)
x_err_var = random.random()
z_err_var = random.random()
if x_err_var > (1 - self.x_error_rate):
q.X()
if z_err_var > (1 - self.z_error_rate):
q.Z()
q.send_to(self.ARP[r].host_id)
Logger.get_instance().log('transfer qubits - received ' + q.id)
# Unblock qubits in case they were blocked
q.blocked = False
if self.ARP[r].q_relay_sniffing:
self.ARP[r].q_relay_sniffing_fn(original_sender, receiver,
q)
route = self.get_quantum_route(sender, receiver)
i = 0
while i < len(route) - 1:
Logger.get_instance().log('sending qubits from ' + route[i] +
' to ' + route[i + 1])
transfer_qubits(route[i + 1], original_sender=route[0])
i += 1
def _process_queue(self):
"""
Runs a thread for processing the packets in the packet queue.
"""
while True:
if self._stop_thread:
break
if not self._packet_queue.empty():
# Artificially delay the network
if self.delay > 0:
time.sleep(self.delay)
packet = self._packet_queue.get()
sender, receiver = packet.sender, packet.receiver
host_sender = self.get_host(sender)
# Find transmission probability of the quantum connection and update network ticks if the packet is a qubit or an EPR signal
if packet.payload_type == Constants.QUANTUM or (
packet.payload_type == Constants.SIGNAL
and isinstance(packet.payload, dict)
and 'q_id' in packet.payload.keys()):
transmission_probability = 1.0
for connection in host_sender.quantum_connections:
if connection.receiver_id == receiver:
transmission_probability = connection.transmission_p
break
# Simulate packet loss
packet_drop_var = random.random()
transmission_var = random.random()
if packet_drop_var > (1 - self.packet_drop_rate):
Logger.get_instance().log("PACKET DROPPED")
if packet.payload_type == Constants.QUANTUM:
packet.payload.release()
continue
# Simulate packet loss due to absorption of qubits in the quantum channel
elif packet.payload_type == Constants.QUANTUM or (
packet.payload_type == Constants.SIGNAL
and isinstance(packet.payload, dict)
and 'q_id' in packet.payload.keys()):
if transmission_var < 1 - transmission_probability:
Logger.get_instance().log("QUBIT TRANSMISSION FAILED")
if packet.payload_type == Constants.QUANTUM:
packet.payload.release()
continue
if packet.payload_type == Constants.QUANTUM:
self._route_quantum_info(sender, receiver,
[packet.payload])
try:
if packet.protocol == Constants.RELAY and not self.use_hop_by_hop:
full_route = packet.route
route = full_route[full_route.index(sender):]
else:
if packet.protocol == Constants.REC_EPR:
route = self.get_classical_route(sender, receiver)
else:
route = self.get_classical_route(sender, receiver)
if len(route) < 2:
raise Exception('No route exists')
elif len(route) == 2:
# Update network ticks
sending_host = self.get_host(route[0])
receiving_host = self.get_host(route[1])
if packet.payload_type == Constants.QUANTUM or (
packet.payload_type == Constants.SIGNAL
and isinstance(packet.payload, dict)
and 'q_id' in packet.payload.keys()):
for connection in sending_host.quantum_connections:
if connection.receiver_id == receiving_host.host_id:
self._tick += int(
float(connection.length * 1000 /
(self._tickspan)) / 300000000)
break
else:
for connection in sending_host.classical_connections:
if connection.receiver_id == receiving_host.host_id:
self._tick += int(
float(connection.length * 1000 /
(self._tickspan)) / 300000000)
break
if packet.protocol != Constants.RELAY:
if packet.protocol == Constants.REC_EPR:
host_sender = self.get_host(sender)
q = host_sender \
.backend \
.create_EPR(host_sender.host_id,
receiver,
q_id=packet.payload['q_id'],
block=packet.payload['blocked'])
host_sender.add_epr(receiver, q)
self.ARP[receiver].rec_packet(packet)
else:
self.ARP[receiver].rec_packet(packet.payload)
else:
# Update network ticks
#for routeidx in range(len(route)-2):
sending_host = self.get_host(route[0])
receiving_host = self.get_host(route[1])
if packet.payload_type == Constants.QUANTUM or (
packet.payload_type == Constants.SIGNAL
and isinstance(packet.payload, dict)
and 'q_id' in packet.payload.keys()):
for connection in sending_host.quantum_connections:
if connection.receiver_id == receiving_host.host_id:
self._tick += int(
float(connection.length * 1000 /
(self._tickspan)) / 300000000)
break
else:
for connection in sending_host.classical_connections:
if connection.receiver_id == receiving_host.host_id:
self._tick += int(
float(connection.length * 1000 /
(self._tickspan)) / 300000000)
break
if packet.protocol == Constants.REC_EPR:
q_id = packet.payload['q_id']
blocked = packet.payload['blocked']
q_route = self.get_quantum_route(sender, receiver)
if self.use_ent_swap:
DaemonThread(self._entanglement_swap,
args=(sender, receiver, q_route,
q_id, packet.seq_num,
blocked))
else:
DaemonThread(self._establish_epr,
args=(sender, receiver, q_id,
packet.seq_num, blocked))
else:
network_packet = self._encode(route, packet)
self.ARP[route[1]].rec_packet(network_packet)
except nx.NodeNotFound:
Logger.get_instance().error(
"route couldn't be calculated, node doesn't exist")
except ValueError:
Logger.get_instance().error(
"route couldn't be calculated, value error")
except Exception as e:
Logger.get_instance().error('Error in network: ' + str(e))
def send(self, packet):
"""
Puts the packet to the packet queue of the network.
Args:
packet (Packet): Packet to be sent
"""
self._packet_queue.put(packet)
def stop(self, stop_hosts=False):
"""
Stops the network.
"""
Logger.get_instance().log("Network stopped")
try:
if stop_hosts:
for host in self.ARP:
self.ARP[host].stop(release_qubits=True)
self._stop_thread = True
if self._backend is not None:
self._backend.stop()
except Exception as e:
Logger.get_instance().error(e)
def start(self, nodes=None, backend=None):
"""
Starts the network.
"""
if backend is None:
self._backend = EQSNBackend()
else:
self._backend = backend
if nodes is not None:
self._backend.start(nodes=nodes)
self._queue_processor_thread = DaemonThread(target=self._process_queue)
def draw_classical_network(self):
"""
Draws a plot of the network.
"""
nx.draw_networkx(self.classical_network,
pos=nx.spring_layout(self.classical_network),
with_labels=True,
hold=False)
plt.show()
def draw_quantum_network(self):
"""
Draws a plot of the network.
"""
nx.draw_networkx(self.quantum_network,
pos=nx.spring_layout(self.quantum_network),
with_labels=True,
hold=False)
plt.show()
def _encode(self, route, payload, ttl=10):
"""
Adds another layer to the packet if route length between sender and receiver is greater than 2. Sets the
protocol flag in this layer to RELAY and payload_type as SIGNAL and adds a variable
Time-To-Live information in this layer.
Args:
route: route of the packet from sender to receiver
payload (Object): Lower layers of the packet
ttl(int): Time-to-Live parameter
Returns:
RoutingPacket: Encoded RELAY packet
"""
if payload.protocol != Constants.RELAY:
packet = RoutingPacket(route[1], '', Constants.RELAY,
Constants.SIGNAL, payload, ttl, route)
else:
packet = payload
packet.sender = route[1]
if self.use_hop_by_hop:
packet.receiver = route[-1]
else:
packet.receiver = route[2]
return packet