def findShortestRoute(self, startNode, destinationName):
# get routes to process by getting all out going links of the starting node
candidateRoutes = Routes(
[Route([link]) for link in startNode.getLinks()])
minRoute = None
# candiate routes are the routes to process.
# they can be empty when no more routes can have distances less than the current minimum distance
# or cannot find any more routes
while candidateRoutes.len() > 0:
# finished routes store the routes connecting start node and end node
finishedRoutes = candidateRoutes.getRoutesEndedWithNode(
destinationName)
_minRoute = finishedRoutes.getMinDistance()
minRoute = _minRoute if minRoute is None or (
_minRoute is not None and
minRoute.getDistance() > _minRoute.getDistance()) else minRoute
# filter out routes having bigger distance than min route
candidateRoutes = Routes([
route for route in candidateRoutes.getRoutes()
if minRoute is None
or route.getDistance() < minRoute.getDistance()
])
# all candidate routes go one step further. Store the new generated routes
candidateRoutes = Routes([Route([]).copyFrom(route).addNextLink(link) \
for route in candidateRoutes.getRoutes() for link in self.findByName(route.getLastLink().child).getLinks() \
if not route.hasNode(link.child) or (link.child == destinationName and startNode.name == destinationName)])
return minRoute
def findRoutesWithMaxRound(self, startNode, destinationName, maxRound):
# get routes to process by getting all out going links of the starting node
candidateRoutes = Routes(
[Route([link]) for link in startNode.getLinks()])
count = 0
finishedRoutes = None
while candidateRoutes.len(
) > 0 and maxRound is not None and count < maxRound:
# finished routes store the routes connecting start node and end node
finishedRoutes = candidateRoutes.getRoutesEndedWithNode(
destinationName).merge(finishedRoutes)
# all candidate routes go one step further. Store the new generated routes
candidateRoutes = Routes([Route([]).copyFrom(route).addNextLink(link) \
for route in candidateRoutes.getRoutes() for link in self.findByName(route.getLastLink().child).getLinks()])
count = count + 1
return finishedRoutes
def findRoutesWithMaxDistance(self, startNode, destinationName, distance):
# get routes to process by getting all out going links of the starting node
candidateRoutes = Routes(
[Route([link]) for link in startNode.getLinks()])
finishedRoutes = None
# define filter function with partial function
lessThanFilterFunc = partial(Dag.distanceLessThanFilter,
distance=distance)
while candidateRoutes.len() > 0:
# finished routes store the routes connecting start node and end node
finishedRoutes = candidateRoutes.getRoutesEndedWithNode(
destinationName).filter(lessThanFilterFunc).merge(
finishedRoutes)
# all candidate routes go one step further. Store the new generated routes
candidateRoutes = Routes([Route([]).copyFrom(route).addNextLink(link) \
for route in candidateRoutes.getRoutes() for link in self.findByName(route.getLastLink().child).getLinks()])
# filter out routes having more distance than the max distance
candidateRoutes = Routes([
route for route in candidateRoutes.getRoutes()
if route.getDistance() < distance
])
return finishedRoutes
