traversal algorithm added

pymote/algorithms/santoro2007/traversal.py

@@ -0,0 +1,174 @@
+from pymote.algorithm import NodeAlgorithm
+from pymote.message import Message
+
+
+class DFT(NodeAlgorithm):
+    required_params = ()
+    default_params = {'neighborsKey': 'Neighbors'}
+
+    def initializer(self):
+        for node in self.network.nodes():
+            node.memory[self.neighborsKey] = \
+                node.compositeSensor.read()['Neighbors']
+            node.status = 'IDLE'
+        ini_node = self.network.nodes()[0]
+        ini_node.status = 'INITIATOR'
+        self.network.outbox.insert(0, Message(header=NodeAlgorithm.INI,
+                                              destination=ini_node))
+
+    def initiator(self, node, message):
+        if message.header == NodeAlgorithm.INI:
+            node.memory["parent"] = None
+            node.memory["unvisited"] = list(node.memory[self.neighborsKey])
+            self.visit(node)
+        else:
+            raise Exception("Dont disturb intitator!")
+
+    def idle(self, node, message):
+        if message.header == 'Token':
+            node.memory["parent"] = message.source
+            node.memory["unvisited"] = list(node.memory[self.neighborsKey])
+            node.memory["unvisited"].remove(node.memory["parent"])
+            self.visit(node)
+        else:
+            raise Exception("Should not be here.")
+
+    def visited(self, node, message):
+        if message.header == 'Token':
+            node.memory["unvisited"].remove(message.source)
+            node.send(Message(header='Backedge',
+                              destination=message.source))
+        elif message.header == 'Return':
+            self.visit(node)
+        elif message.header == 'Backedge':
+            self.visit(node)
+
+    def done(self, node, message):
+        raise Exception("Im done!!!")
+
+    def visit(self, node):
+        if len(node.memory["unvisited"]) == 0:
+            if node.memory["parent"] is not None:
+                node.send(Message(header='Return',
+                                  destination=node.memory["parent"]))
+            node.status = "DONE"
+        else:
+            next_unvisited = node.memory["unvisited"].pop()
+            node.send(Message(header='Token',
+                              destination=next_unvisited))
+            node.status = "VISITED"
+
+    STATUS = {
+        'INITIATOR': initiator,
+        'IDLE': idle,
+        'VISITED': visited,
+        'DONE': done,
+    }
+
+
+class DFStar(NodeAlgorithm):
+    required_params = ()
+    default_params = {'neighborsKey': 'Neighbors'}
+
+    def initializer(self):
+        for node in self.network.nodes():
+            node.memory[self.neighborsKey] = \
+                node.compositeSensor.read()['Neighbors']
+            node.status = 'IDLE'
+        ini_node = self.network.nodes()[0]
+        ini_node.status = 'INITIATOR'
+        self.network.outbox.insert(0, Message(header=NodeAlgorithm.INI,
+                                              destination=ini_node))
+
+    def initiator(self, node, message):
+        if message.header == NodeAlgorithm.INI:
+            node.memory['initiator'] = True
+            node.memory['unvisited'] = list(node.memory[self.neighborsKey])
+            node.memory['next'] = node.memory['unvisited'].pop()
+            if (node.memory['unvisited']):
+                node.send(Message(header='T',
+                                  destination=node.memory['next']))
+                node.send(Message(header='Visited',
+                                  destination=node.memory['unvisited']))
+                node.status = 'VISITED'
+            else:
+                node.status = 'DONE'
+
+    def idle(self, node, message):
+        if message.header == 'T':
+            node.memory['unvisited'] = list(node.memory[self.neighborsKey])
+            self.first_visit(node, message)
+
+        if message.header == 'Visited':
+            node.memory['unvisited'] = list(node.memory[self.neighborsKey])
+            node.memory['unvisited'].remove(message.source)
+            node.status = 'AVAILABLE'
+
+    def available(self, node, message):
+        if message.header == 'T':
+            self.first_visit(node, message)
+
+        if message.header == 'Visited':
+            node.memory['unvisited'].remove(message.source)
+
+    def visited(self, node, message):
+        if message.header == 'T':
+            node.memory['unvisited'].remove(message.source)
+            # late visited, should not happen in unitary communication delay
+            if node.memory['next'] == message.source:
+                self.visit(node, message)
+
+        if message.header == 'Visited':
+            node.memory['unvisited'].remove(message.source)
+            if node.memory['next'] == message.source:
+                self.visit(node, message)
+
+        if message.header == 'Return':
+            self.visit(node, message)
+
+    def done(self, node, message):
+        pass
+
+    def first_visit(self, node, message):
+        # TODO: initiator is redundant - it can be deduced from entry==None
+        node.memory['initiator'] = False
+        node.memory['entry'] = message.source
+        try:
+            node.memory['unvisited'].remove(message.source)
+        except ValueError:
+            pass
+        if (node.memory['unvisited']):
+            node.memory['next'] = node.memory['unvisited'].pop()
+            node.send(Message(header='T',
+                              destination=node.memory['next']))
+            node.send(Message(header='Visited',
+                              destination=set(node.memory[self.neighborsKey]) -
+                              set([node.memory['entry'],
+                                   node.memory['next']])))
+            node.status = 'VISITED'
+        else:
+            node.send(Message(header='Return',
+                              destination=node.memory['entry']))
+            node.send(Message(header='Visited',
+                              destination=set(node.memory[self.neighborsKey]) -
+                              set([node.memory['entry']])))
+            node.status = 'DONE'
+
+    def visit(self, node, message):
+        if (node.memory['unvisited']):
+            node.memory['next'] = node.memory['unvisited'].pop()
+            node.send(Message(header='T',
+                              destination=node.memory['next']))
+        else:
+            if not node.memory['initiator']:
+                node.send(Message(header='Return',
+                                  destination=node.memory['entry']))
+            node.status = 'DONE'
+
+    STATUS = {
+        'INITIATOR': initiator,
+        'IDLE': idle,
+        'AVAILABLE': available,
+        'VISITED': visited,
+        'DONE': done,
+    }