|  | # Copyright 2014 Google Inc. All Rights Reserved. | 
|  | # | 
|  | # Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | # you may not use this file except in compliance with the License. | 
|  | # You may obtain a copy of the License at | 
|  | # | 
|  | #      http://www.apache.org/licenses/LICENSE-2.0 | 
|  | # | 
|  | # Unless required by applicable law or agreed to in writing, software | 
|  | # distributed under the License is distributed on an "AS IS" BASIS, | 
|  | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | # See the License for the specific language governing permissions and | 
|  | # limitations under the License. | 
|  |  | 
|  | """App Engine memcache based cache for the discovery document.""" | 
|  |  | 
|  | import logging | 
|  |  | 
|  | # This is only an optional dependency because we only import this | 
|  | # module when google.appengine.api.memcache is available. | 
|  | from google.appengine.api import memcache | 
|  |  | 
|  | from . import base | 
|  | from ..discovery_cache import DISCOVERY_DOC_MAX_AGE | 
|  |  | 
|  |  | 
|  | LOGGER = logging.getLogger(__name__) | 
|  |  | 
|  | NAMESPACE = "google-api-client" | 
|  |  | 
|  |  | 
|  | class Cache(base.Cache): | 
|  | """A cache with app engine memcache API.""" | 
|  |  | 
|  | def __init__(self, max_age): | 
|  | """Constructor. | 
|  |  | 
|  | Args: | 
|  | max_age: Cache expiration in seconds. | 
|  | """ | 
|  | self._max_age = max_age | 
|  |  | 
|  | def get(self, url): | 
|  | try: | 
|  | return memcache.get(url, namespace=NAMESPACE) | 
|  | except Exception as e: | 
|  | LOGGER.warning(e, exc_info=True) | 
|  |  | 
|  | def set(self, url, content): | 
|  | try: | 
|  | memcache.set(url, content, time=int(self._max_age), namespace=NAMESPACE) | 
|  | except Exception as e: | 
|  | LOGGER.warning(e, exc_info=True) | 
|  |  | 
|  |  | 
|  | cache = Cache(max_age=DISCOVERY_DOC_MAX_AGE) |