Expire appcaches that fail to update for "too long".

content/browser/appcache/appcache_group.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_APPCACHE_APPCACHE_GROUP_H_
 #define CONTENT_BROWSER_APPCACHE_APPCACHE_GROUP_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 20 matching lines @@
 class HostObserver;
 class MockAppCacheStorage;
 
 // Collection of application caches identified by the same manifest URL.
 // A group exists as long as it is in use by a host or is being updated.
 class CONTENT_EXPORT AppCacheGroup
     : public base::RefCounted<AppCacheGroup> {
  public:
 
   class CONTENT_EXPORT UpdateObserver {
-    public:
-      // Called just after an appcache update has completed.
-      virtual void OnUpdateComplete(AppCacheGroup* group) = 0;
-      virtual ~UpdateObserver() {}
+   public:
+    // Called just after an appcache update has completed.
+    virtual void OnUpdateComplete(AppCacheGroup* group) = 0;
+    virtual ~UpdateObserver() {}
   };
 
   enum UpdateAppCacheStatus {
     IDLE,
     CHECKING,
     DOWNLOADING,
   };
 
   AppCacheGroup(AppCacheStorage* storage, const GURL& manifest_url,
                 int64 group_id);
 
   // Adds/removes an update observer, the AppCacheGroup does not take
   // ownership of the observer.
   void AddUpdateObserver(UpdateObserver* observer);
   void RemoveUpdateObserver(UpdateObserver* observer);
 
   int64 group_id() const { return group_id_; }
   const GURL& manifest_url() const { return manifest_url_; }
-  const base::Time& creation_time() const { return creation_time_; }
-  void set_creation_time(const base::Time& time) { creation_time_ = time; }
+  base::Time creation_time() const { return creation_time_; }
+  void set_creation_time(base::Time time) { creation_time_ = time; }
   bool is_obsolete() const { return is_obsolete_; }
   void set_obsolete(bool value) { is_obsolete_ = value; }
-
   bool is_being_deleted() const { return is_being_deleted_; }
   void set_being_deleted(bool value) { is_being_deleted_ = value; }
+  base::Time last_full_update_check_time() const {
+    return last_full_update_check_time_;
+  }
+  void set_last_full_update_check_time(base::Time time) {
+    last_full_update_check_time_ = time;
+  }
+  base::Time first_evictable_error_time() const {
+    return first_evictable_error_time_;
+  }
+  void set_first_evictable_error_time(base::Time time) {
+    first_evictable_error_time_ = time;
+  }
 
   AppCache* newest_complete_cache() const { return newest_complete_cache_; }
 
   void AddCache(AppCache* complete_cache);
   void RemoveCache(AppCache* cache);
   bool HasCache() const { return newest_complete_cache_ != NULL; }
 
   void AddNewlyDeletableResponseIds(std::vector<int64>* response_ids);
 
   UpdateAppCacheStatus update_status() const { return update_status_; }
@@ skipping 48 matching lines @@
   void HostDestructionImminent(AppCacheHost* host);
 
   const int64 group_id_;
   const GURL manifest_url_;
   base::Time creation_time_;
   UpdateAppCacheStatus update_status_;
   bool is_obsolete_;
   bool is_being_deleted_;
   std::vector<int64> newly_deletable_response_ids_;
 
+  // Most update checks respect the cache control headers of the manifest
+  // resource, but we bust the http cache for a "full" update check after 24

[palmer, 2015/06/01 21:09:02]

Nit: What does "bust" mean here? Invalidate?

[michaeln, 2015/06/19 21:38:19]

as in cache-busting, i used the term "bypass" instead

+  // hours since the last full check was successfully performed.
+  base::Time last_full_update_check_time_;
+
+  // Groups that fail to update for a sufficiently long time are evicted. This
+  // value is reset after a successful update or update check.
+  base::Time first_evictable_error_time_;
+
   // Old complete app caches.
   Caches old_caches_;
 
   // Newest cache in this group to be complete, aka relevant cache.
   AppCache* newest_complete_cache_;
 
   // Current update job for this group, if any.
   AppCacheUpdateJob* update_job_;
 
   // Central storage object.
@@ skipping 16 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(content::AppCacheGroupTest, QueueUpdate);
   FRIEND_TEST_ALL_PREFIXES(content::AppCacheUpdateJobTest, AlreadyChecking);
   FRIEND_TEST_ALL_PREFIXES(content::AppCacheUpdateJobTest, AlreadyDownloading);
 
   DISALLOW_COPY_AND_ASSIGN(AppCacheGroup);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_APPCACHE_APPCACHE_GROUP_H_