def route_from_coord(request):
"""
Responds with a route starting and ending in a certain coordinate
This function uses the lightning rod (Stroobant) algorithm: it generates a
rod through the city and then tries different paths going to that rod
Query args:
lat -- coordinate latitude
lon -- coordinate longitude
type -- the response type. See the geojson.respond_path function for more details
"""
edge_tuple = get_edge_tuple(request, request.GET.get('lat'),
request.GET.get('lon'))
if edge_tuple is None:
# This happens when the requested coordinates are not within the Graph.
return HttpResponseNotFound()
(start, end) = edge_tuple
config = routing_config.from_dict(DEFAULT_ROUTING_CONFIG,
request.GET.dict())
# Calculations
tpexec = Executor(max_workers=NUM_THREADS)
routes = []
flist = []
# Sometimes, routing gives a bad response. To fix this, the routing algorithm
# is performed multiple times in an (a)synchronous way.
for i in xrange(NUM_THREADS):
flist.append(tpexec.submit(async_exec, GRAPH, start, end, config))
for _i in xrange(NUM_THREADS * 10):
sets = wait(flist, return_when=FIRST_COMPLETED)
flist = list(sets.not_done)
for fut in sets.done:
routes = fut.result()
if len(routes) > 0:
break
flist.append(tpexec.submit(async_exec, GRAPH, start, end, config))
tpexec.shutdown(False)
# Choose a random route from all possible routes.
shuffle(routes)
print path_length(GRAPH, routes[0])
resp = respond_path(request.GET, routes[0], [routes[0][0]])
if resp is None:
return HttpResponseNotFound()
return HttpResponse(into_json(resp))
def get_id_from_pos(request):
"""
Respond with the node index closest to the given coordinate.
Query args:
lat -- coordinate latitude
lon -- coordinate longitude
"""
try:
tup = get_edge_tuple(request, request.GET.get('lat'),
request.GET.get('lon'))
if tup is None:
return HttpResponseNotFound()
return HttpResponse(into_json(tup))
except BaseException:
return HttpResponseBadRequest()
def get_node_from_pos(request):
"""
Respond with the node data closest to the given coordinate.
Query args:
lat -- coordinate latitude
lon -- coordinate longitude
"""
try:
tup = get_edge_tuple(request, request.GET.get('lat'),
request.GET.get('lon'))
except BaseException:
return HttpResponseBadRequest()
if tup is None:
return HttpResponse('[]')
tup = map(city.GRAPH.get, tup)
return HttpResponse(into_json(tup))
def test_get_edge_tuple(self):
util.get_edge_tuple(None, 51.0, 3.8)
def go_home(request):
"""
Responds with a route leading the user back to his starting point.
Query args:
tag -- the route that the user used to run.
lon, lat -- position of the user.
distance -- The preferred distance to the starting point.
"""
# Get path from request tag
tag = request.GET.get('tag')
path = from_string(GRAPH, tag)
# Find nearest node
(start, end) = get_edge_tuple(request, request.GET.get('lat'),
request.GET.get('lon'))
# Get the preferred distance to run from this point to starting position (0 means straight home)
dist_arg = float(request.GET.get('distance'))
if dist_arg == 0:
dist = distance(serialize_node(GRAPH, end),
serialize_node(GRAPH, path[0]))
else:
dist = dist_arg
print dist
# Get index of current location and close rod to return
if end not in path and start in path:
(end, start) = (start, end)
elif not (end in path or start in path):
for node in serialize_node(GRAPH, end).connections + serialize_node(
GRAPH, start).connections:
if node.node in path:
end = node.node
break
ind = path.index(end)
# Nodes from starting to current position
pois_path = path[ind:0:-1]
dist = dist - path_length(GRAPH, pois_path)
d = {k: v for k, v in request.GET.dict().items()}
d['min_length'] = str(dist)
d['max_length'] = str(dist + 1.0)
config = routing_config.from_dict(DEFAULT_ROUTING_CONFIG, d)
# Generate new random rod from starting position
nodes = generate_rod(GRAPH, path[0], config)
# Create new rod that will be used for the poisoning (starting from current position and contains starting pos)
pois_path.extend(nodes)
print "tag =", into_string(GRAPH, nodes)
# Close the rod on the starting position
routes = close_rod(GRAPH, end, pois_path, config, nodes)
# Will result in the shortest route returned
if dist_arg == 0:
routes = sorted(routes, key=len)
else:
shuffle(routes)
print path_length(GRAPH, routes[0])
# Return the new route, i.e. the completed part + new part
selected_route = path[0:ind] + routes[0][::-1]
resp = respond_path(request.GET, selected_route, [selected_route[0]])
if resp is None:
return HttpResponseNotFound()
return HttpResponse(into_json(resp))