def async_get(self):
shapefile_dir = os.path.join(self.precache.directory, safe64.dir(self.get_url))
shapefile_path = [f for f in os.listdir(shapefile_dir) if f.endswith("shp")][0]
self.jsonp(
{"data_url": self.get_url, "srs": self.shapefile_projection(os.path.join(shapefile_dir, shapefile_path))},
self.get_argument("jsoncallback", None),
)
self.finish()
def cache(self, response):
""" asynchttp request callback. caches the downloaded zipfile. """
try:
# Check that the directory does not exist yet, as there *can* be
# concurrent jobs at this point. Do not actually create the
# directory until we are sure that a successful shapefile can be
# extracted from a zip.
base_dir = os.path.join(self.directory, safe64.dir(response.request.url))
if not os.path.isdir(base_dir):
self.unzip_shapefile(response.body, base_dir, response.request)
except Exception, e:
logging.info('Failed: %s', response.request.url)
logging.info('Exception: %s', e)
if response.request.url in self.locks : self.locks.remove(response.request.url)
if response.request.url not in self.queue : self.queue.append(response.request.url)
self.request_handler.finish()
return
def process_request(self, request_url):
# Directory exists, request has already been successfully processed.
base_dir = os.path.join(self.directory, safe64.dir(request_url))
if os.path.isdir(base_dir):
if request_url in self.queue: self.queue.remove(request_url)
if request_url in self.locks: self.locks.remove(request_url)
# Request is in queue and not locked. Fire asynchronous HTTP request.
elif request_url in self.queue and request_url not in self.locks:
self.queue.remove(request_url)
self.locks.append(request_url)
logging.info("Locked: %s", request_url)
http = tornado.httpclient.AsyncHTTPClient()
http.fetch(request_url, request_timeout=60, callback=self.cache)
# Request is in locks. Perform a holding pattern.
elif request_url in self.locks:
tornado.ioloop.IOLoop.instance().add_timeout(
time.time() + 5, lambda: self.process_request(request_url))
# All queued requests have been processed. Continue to callback.
if len(self.queue) == 0 and len(self.locks) == 0:
self.callback(**self.kwargs)
return
def url2fs(self, url):
""" encode a URL to be safe as a filename """
uri, extension = os.path.splitext(url)
return safe64.dir(uri) + extension
