Files
dataservices-api/server/lib/python/cartodb_services/cartodb_services/mapzen/routing.py
2018-01-04 15:00:52 +01:00

150 lines
5.6 KiB
Python

import requests
import json
import re
from requests.adapters import HTTPAdapter
from cartodb_services.tools.exceptions import (WrongParams,
MalformedResult,
ServiceException)
from cartodb_services.tools.qps import qps_retry
from cartodb_services.tools import Coordinate, PolyLine
from cartodb_services.metrics import MetricsDataGatherer, Traceable
class MapzenRouting(Traceable):
'A Mapzen Routing wrapper for python'
PRODUCTION_ROUTING_BASE_URL = 'https://valhalla.mapzen.com/route'
READ_TIMEOUT = 60
CONNECT_TIMEOUT = 10
MAX_RETRIES=1
ACCEPTED_MODES = {
"walk": "pedestrian",
"car": "auto",
"public_transport": "bus",
"bicycle": "bicycle"
}
AUTO_SHORTEST = 'auto_shortest'
OPTIONAL_PARAMS = [
'mode_type',
]
METRICS_UNITS = 'kilometers'
IMPERIAL_UNITS = 'miles'
def __init__(self, app_key, logger, service_params=None):
service_params = service_params or {}
self._app_key = app_key
self._logger = logger
self._url = service_params.get('base_url', self.PRODUCTION_ROUTING_BASE_URL)
self._connect_timeout = service_params.get('connect_timeout', self.CONNECT_TIMEOUT)
self._read_timeout = service_params.get('read_timeout', self.READ_TIMEOUT)
self._max_retries = service_params.get('max_retries', self.MAX_RETRIES)
@qps_retry
def calculate_route_point_to_point(self, waypoints, mode,
options=[], units=METRICS_UNITS):
parsed_options = self.__parse_options(options)
mode_param = self.__parse_mode_param(mode, parsed_options)
directions = self.__parse_directions(waypoints)
json_request_params = self.__parse_json_parameters(directions,
mode_param,
units)
request_params = self.__parse_request_parameters(json_request_params)
# TODO Extract HTTP client wrapper
session = requests.Session()
session.mount(self._url, HTTPAdapter(max_retries=self._max_retries))
response = session.get(self._url, params=request_params,
timeout=(self._connect_timeout, self._read_timeout))
self.add_response_data(response, self._logger)
if response.status_code == requests.codes.ok:
return self.__parse_routing_response(response.text)
elif response.status_code == requests.codes.bad_request:
return MapzenRoutingResponse(None, None, None)
else:
self._logger.error('Error trying to calculate route using Mapzen',
data={"response_status": response.status_code,
"response_reason": response.reason,
"response_content": response.text,
"reponse_url": response.url,
"response_headers": response.headers,
"waypoints": waypoints, "mode": mode,
"options": options})
raise ServiceException('Error trying to calculate route using Mapzen', response)
def __parse_options(self, options):
return dict(option.split('=') for option in options)
def __parse_request_parameters(self, json_request):
request_options = {"json": json_request}
request_options.update({'api_key': self._app_key})
return request_options
def __parse_json_parameters(self, directions, mode, units):
json_options = directions
json_options.update({'costing': self.ACCEPTED_MODES[mode]})
json_options.update({"directions_options": {'units': units,
'narrative': False}})
return json.dumps(json_options)
def __parse_directions(self, waypoints):
path = []
for idx, point in enumerate(waypoints):
if idx == 0 or idx == len(waypoints) - 1:
point_type = 'break'
else:
point_type = 'through'
path.append({"lon": str(point.longitude), "lat": str(point.latitude), "type": point_type})
return {"locations": path}
def __parse_routing_response(self, response):
try:
parsed_json_response = json.loads(response)
legs = parsed_json_response['trip']['legs'][0]
shape = PolyLine().decode(legs['shape'])
length = legs['summary']['length']
duration = legs['summary']['time']
return MapzenRoutingResponse(shape, length, duration)
except IndexError:
return []
except KeyError:
raise MalformedResult()
def __parse_mode_param(self, mode, options):
if mode in self.ACCEPTED_MODES:
mode_source = self.ACCEPTED_MODES[mode]
else:
raise WrongParams("{0} is not an accepted mode type".format(mode))
if mode == self.ACCEPTED_MODES['car'] and 'mode_type' in options and \
options['mode_type'] == 'shortest':
mode = self.AUTO_SHORTEST
return mode
class MapzenRoutingResponse:
def __init__(self, shape, length, duration):
self._shape = shape
self._length = length
self._duration = duration
@property
def shape(self):
return self._shape
@property
def length(self):
return self._length
@property
def duration(self):
return self._duration