def __getitem__(self, key):
if self.cache_responses:
if key in self.seen_layers:
return self.seen_layers[key]
elif key in self.lookup_failures:
# If we are caching, raise KnownUnknown if we have previously failed to find this layer
raise TileStache.KnownUnknown("Layer %s previously not found",
key)
logging.debug("Requesting layer %s", self.url_root + "/layer/" + key)
res = urlopen(self.url_root + "/layer/" + key)
if (res.getcode() != 200):
logging.info("Config response code %s for %s", res.getcode(), key)
if (self.cache_responses):
self.lookup_failures.add(key)
raise TileStache.KnownUnknown("Layer %s not found", key)
try:
layer = self.parse_layer(res)
self.seen_layers[key] = layer
return layer
except ValueError:
logging.error("Invalid JSON response seen for %s", key)
if (self.cache_responses):
# If caching responses, cache this failure
self.lookup_failures.add(key)
# KnownUnknown seems like the appropriate thing to raise here since this is akin
# to a missing configuration.
raise TileStache.KnownUnknown(
"Failed to parse JSON configuration for %s", key)
