Adds bandwidth delay to routers

pydtn/network.py

@@ -82,10 +82,10 @@ class Network:
     def send_link(self, a, b, packet):
         ''''''
         if self.graph[a][b]['state']:
-            # TODO: transfer delay
             b.recv(packet)
+            return True
         else:
-            raise Exception('Nodes {} and {} not connected'.format(a, b))
+            return False
 
     def __getitem__(self, node):
         ''''''

pydtn/node.py

 from collections import Iterable
 
+from simpy import Store
+
 from .buffer import Buffer
 from .core import TickProcess
 
@@ -19,6 +21,8 @@ class Node(TickProcess):
         self.network = network
         self.id = nid
 
+        self.bandwidth = float('inf')
+
         self.buffer = Buffer(self.env, capacity=buffer_size)
 
         if router is None:
@@ -27,6 +31,8 @@ class Node(TickProcess):
 
         self.start(self.env)
 
+        self.transfer_queue = Store(self.env)
+
     def route_packets(self):
         packets_to_delete = []
 
@@ -47,26 +53,47 @@ class Node(TickProcess):
             if not isinstance(targets, Iterable):
                 targets = [targets]
 
-            # send the packet
-            self.send(targets, packet, reason)
+            # add the packet to the transfer queue
+            self.transfer_queue.put((packet, targets, reason))
+            #self.send(targets, packet, reason)
 
             # if the router requested deletion from the buffer do it
             if delete:
                 packets_to_delete.append(packet)
 
+
         for packet in packets_to_delete:
             self.buffer.remove(packet)
 
     def process(self, **kwargs):
         ''''''
         while True:
-            yield self.tick()
+            packet, targets, reason = yield self.transfer_queue.get()
+
+            # simulate transfer delay of packet
+            delay = packet.size / self.bandwidth
+            yield self.env.timeout(delay)
 
+            success = []
+            # simulates broadcast
+            for target in targets:
+                # try sending packet
+                if self.network.send_link(self, target, packet):
+                    success.append(target)
+                    self.router.on_send_success(target, packet)
+                else:
+                    self.router.on_send_failure(target, packet)
+
+            packet.send(self, success, reason=reason)
+
+
+    '''
     def send(self, targets, packet, reason):
         # TODO: transfer delay
         packet.send(self, targets, reason=reason)
         for target in targets:
             self.network.send_link(self, target, packet)
+    '''
 
     def recv(self, packet):
         if packet.destination == self:
@@ -78,17 +105,19 @@ class Node(TickProcess):
     def community(self):
         return self.network.community[self]
 
+    def connected_to(self, other):
+        return self.network[self][other]['state']
+
     @property
     def links(self):
         '''
         Returns a list of connected links.
         '''
-        links = {
+        return {
             met: data
             for met, data in self.network[self].items()
-            if data['state']
+            if self.connected_to(met)
         }
-        return links
 
     def __repr__(self):
         return 'Node(id={})'.format(self.id)

pydtn/packet.py

@@ -61,6 +61,7 @@ class Packet:
         self.destination = destination
         self.ttl = ttl
         self.payload = payload
+        self.size = 0
 
         self.path = []
 

pydtn/routers/base.py

@@ -11,3 +11,8 @@ class Router:
     def __call__(self, packet):
         raise NotImplementedError
 
+    def on_send_success(self, packet, target):
+        pass
+
+    def on_send_failure(self, packet, target):
+        pass

pydtn/routers/bubble.py

@@ -17,3 +17,6 @@ class BubbleRouter(CommunityRouter):
 
         return None, None, False
 
+    def on_send_failure(self, target, packet):
+        self.node.buffer.add(packet)
+

pydtn/routers/direct.py

@@ -6,3 +6,6 @@ class DirectRouter(Router):
             return packet.destination, 'direct', True
         return None, None, False
 
+    def on_send_failure(self, target, packet):
+        self.node.buffer.add(packet)
+

pydtn/routers/epidemic.py

@@ -17,9 +17,6 @@ class EpidemicRouter(Router):
             if met not in self.sent[packet]
         ]
 
-        # update set of nodes a packet was sent to
-        self.sent[packet].update(targets)
-
         # return list of nodes to send packet to
         # (targets, remove from buffer, reason)
         if targets:
@@ -27,3 +24,6 @@ class EpidemicRouter(Router):
         else:
             return None, None, False
 
+    def on_send_success(self, target, packet):
+        self.sent[packet].add(target)
+

pydtn/routers/hcbf.py

@@ -33,3 +33,6 @@ class HCBFRouter(CommunityRouter):
 
         return None, None, False
 
+    def on_send_failure(self, target, packet):
+        self.node.buffer.add(packet)
+