app and API: switch caching to use webutil's @memcache_response

for #135

api.py

@@ -23,6 +23,7 @@
 Atom format spec:
 http://atomenabled.org/developers/syndication/
 """
+import datetime
 import json
 import logging
 import urllib
@@ -53,6 +54,7 @@
 <response>%s</response>
 """
 ITEMS_PER_PAGE = 100
+RESPONSE_CACHE_TIME = datetime.timedelta(minutes=5)
 
 # default values for each part of the API request path except the site, e.g.
 # /twitter/@me/@self/@all/...
@@ -80,19 +82,16 @@
 class Handler(handlers.ModernHandler):
   """Base class for API handlers.
 
-  Response data is cached. Cache key is 'R [PATH]', value is dict with
-  'activities' and 'actor' keys. Cache duration defaults to 5m but silos can
-  override, eg Instagram sets to 60m. Background:
-  https://github.com/snarfed/bridgy/issues/665
-
-  You can skip the cache by including a cache=false query param.
+  Responses are cached for 5m. You can skip the cache by including a cache=false
+  query param. Background: https://github.com/snarfed/bridgy/issues/665
 
   Attributes:
     source: Source subclass
   """
   handle_exception = handlers.handle_exception
 
   @canonicalize_domain
+  @handlers.memcache_response(RESPONSE_CACHE_TIME)
   def get(self):
     """Handles an API GET.
 
@@ -139,17 +138,6 @@ def get(self):
                                    (src.DOMAIN, arg, domain))
         args[i] = id
 
-    # check if request is cached
-    cache = self.request.get('cache', '').lower() != 'false'
-    if cache:
-      cache_key = 'R %s' % self.request.url
-      cached = memcache.get(cache_key)
-      if cached:
-        logging.info('Serving cached response %r', cache_key)
-        self.write_response(cached['response'], actor=cached['actor'],
-                            url=src.BASE_URL)
-        return
-
     # handle default path elements
     args = [None if a in defaults else a
             for a, defaults in zip(args, PATH_DEFAULTS)]
@@ -177,12 +165,6 @@ def get(self):
 
     self.write_response(response, actor=actor, url=src.BASE_URL)
 
-    # cache response
-    if cache:
-      logging.info('Caching response in %r', cache_key)
-      memcache.set(cache_key, {'response': response, 'actor': actor},
-                   src.RESPONSE_CACHE_TIME)
-
   def write_response(self, response, actor=None, url=None, title=None):
     """Converts ActivityStreams activities and writes them out.
 

app.py

@@ -50,7 +50,6 @@
   'jsonfeed',
   'mf2-json',
 )
-URL_CACHE_TIME = 5 * 60  # 5m
 SILO_DOMAINS = {cls.DOMAIN for cls in (
   Facebook,
   Flickr,
@@ -116,14 +115,13 @@ def get(self):
 class UrlHandler(api.Handler):
   """Handles URL requests from the interactive demo form on the front page.
 
-  Fetched URL data is cached for 5m. Cache key is 'U [URL]', value is dict with
-  'url' and 'body'. Background: https://github.com/snarfed/bridgy/issues/665
-
-  You can skip the cache by including a cache=false query param.
+  Responses are cached for 5m. You can skip the cache by including a cache=false
+  query param. Background: https://github.com/snarfed/bridgy/issues/665
   """
   handle_exception = handlers.handle_exception
 
   @api.canonicalize_domain
+  @handlers.memcache_response(api.RESPONSE_CACHE_TIME)
   def get(self):
     input = util.get_required_param(self, 'input')
     if input not in INPUTS:
@@ -187,35 +185,17 @@ def fetch_mf2_func(url):
 
   def _fetch(self, url):
     """Fetches url and returns (string final url, unicode body)."""
-    # check if request is cached
-    cache = self.request.get('cache', '').lower() != 'false'
-    cache_key = 'U %s' % url
-    cached = memcache.get(cache_key) if cache else None
-
-    if cached:
-      logging.info('Serving cached response %r', cache_key)
-      url = cached['url']
-      body = cached['body']
-    else:
-      # fetch url
-      try:
-        resp = util.requests_get(url)
-      except (ValueError, requests.URLRequired) as e:
-        self.abort(400, str(e))
-        # other exceptions are handled by webutil.handlers.handle_exception(),
-        # which uses interpret_http_exception(), etc.
-
-      if url != resp.url:
-        url = resp.url
-        logging.info('Redirected to %s', url)
-      body = resp.text
-
-      if cache:
-        logging.info('Caching response in %r', cache_key)
-        try:
-          memcache.set(cache_key, {'url': url, 'body': body}, URL_CACHE_TIME)
-        except ValueError:
-          logging.warning('Response is too big for memcache!')
+    try:
+      resp = util.requests_get(url)
+    except (ValueError, requests.URLRequired) as e:
+      self.abort(400, str(e))
+      # other exceptions are handled by webutil.handlers.handle_exception(),
+      # which uses interpret_http_exception(), etc.
+
+    if url != resp.url:
+      url = resp.url
+      logging.info('Redirected to %s', url)
+    body = resp.text
 
     return url, body
 

granary/instagram.py

@@ -55,7 +55,6 @@ class Instagram(source.Source):
   BASE_URL = 'https://www.instagram.com/'
   NAME = 'Instagram'
   FRONT_PAGE_TEMPLATE = 'templates/instagram_index.html'
-  RESPONSE_CACHE_TIME = 60 * 60  # 60m
 
   EMBED_POST = """
   <script async defer src="//platform.instagram.com/en_US/embeds.js"></script>

granary/source.py

@@ -172,7 +172,6 @@ class Source(object):
   """
   __metaclass__ = SourceMeta
 
-  RESPONSE_CACHE_TIME = 5 * 60  # 5m
   POST_ID_RE = None
 
   def user_url(self, user_id):