Add a SiteEngagementEvictionPolicy.

storage/browser/quota/quota_manager.h

 // Copyright 2013 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 STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_
 #define STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 51 matching lines @@
   int64 quota;
   int64 available_disk_space;
 
   UsageAndQuota();
   UsageAndQuota(int64 usage,
                 int64 global_limited_usage,
                 int64 quota,
                 int64 available_disk_space);
 };
 
+// TODO(calamity): Use this in the temporary storage eviction path.
+// An interface for deciding which origin's temporary storage should be evicted
+// when the quota is exceeded.
+class STORAGE_EXPORT QuotaEvictionPolicy {
+ public:
+  // Returns the next origin to evict.  It might return an empty GURL when there
+  // are no evictable origins.
+  virtual void GetEvictionOrigin(
+      const scoped_refptr<SpecialStoragePolicy>& special_storage_policy,
+      const std::map<GURL, int64>& usage_map,
+      int64 global_quota,
+      const GetOriginCallback& callback) = 0;
+
+ protected:
+  ~QuotaEvictionPolicy() {}

[michaeln, 2015/08/26 23:32:37]

Should this dtor be virtual and/or public?

What's the intent of the protected non-virtual destructor? The derived class has
a public virtual dtor. The mix of those is a little odd.

This CL doesn't yet establish ownership of eviction policy objects or how the
quota system gets a ptr to the derived instance. It might make sense for the QM
to get an own ptr to an evictionhandler in its constructor? Did you have
anything in particular in mind.

[calamity, 2015/08/27 05:05:01]

Oops. Yes, this destructor doesn't need to be defined just yet. I think I needed
it for refptr stuff which isn't in this patch? Removing.

I had the full hook-up sorted in another patch which I'm updating and will
upload soon.

+};
+
 // An interface called by QuotaTemporaryStorageEvictor.
 class STORAGE_EXPORT QuotaEvictionHandler {
  public:
-  typedef base::Callback<void(const GURL&)> GetLRUOriginCallback;
   typedef StatusCallback EvictOriginDataCallback;
   typedef base::Callback<void(QuotaStatusCode status,
                               const UsageAndQuota& usage_and_quota)>
       UsageAndQuotaCallback;
 
-  // Returns the least recently used origin.  It might return empty
-  // GURL when there are no evictable origins.
-  virtual void GetLRUOrigin(
-      StorageType type,
-      const GetLRUOriginCallback& callback) = 0;
+  // Returns next origin to evict.  It might return an empty GURL when there are
+  // no evictable origins.
+  virtual void GetEvictionOrigin(StorageType type,
+                                 const GetOriginCallback& callback) = 0;
 
   virtual void EvictOriginData(
       const GURL& origin,
       StorageType type,
       const EvictOriginDataCallback& callback) = 0;
 
   virtual void GetUsageAndQuotaForEviction(
       const UsageAndQuotaCallback& callback) = 0;
 
  protected:
@@ skipping 259 matching lines @@
 
   void DidOriginDataEvicted(QuotaStatusCode status);
 
   void ReportHistogram();
   void DidGetTemporaryGlobalUsageForHistogram(int64 usage,
                                               int64 unlimited_usage);
   void DidGetPersistentGlobalUsageForHistogram(int64 usage,
                                                int64 unlimited_usage);
 
   // QuotaEvictionHandler.
-  void GetLRUOrigin(StorageType type,
-                    const GetLRUOriginCallback& callback) override;
+  void GetEvictionOrigin(StorageType type,
+                         const GetOriginCallback& callback) override;
   void EvictOriginData(const GURL& origin,
                        StorageType type,
                        const EvictOriginDataCallback& callback) override;
   void GetUsageAndQuotaForEviction(
       const UsageAndQuotaCallback& callback) override;
 
+  void GetLRUOrigin(StorageType type, const GetOriginCallback& callback);
+
   void DidSetTemporaryGlobalOverrideQuota(const QuotaCallback& callback,
                                           const int64* new_quota,
                                           bool success);
   void DidGetPersistentHostQuota(const std::string& host,
                                  const int64* quota,
                                  bool success);
   void DidSetPersistentHostQuota(const std::string& host,
                                  const QuotaCallback& callback,
                                  const int64* new_quota,
                                  bool success);
@@ skipping 18 matching lines @@
   const bool is_incognito_;
   const base::FilePath profile_path_;
 
   scoped_refptr<QuotaManagerProxy> proxy_;
   bool db_disabled_;
   bool eviction_disabled_;
   scoped_refptr<base::SingleThreadTaskRunner> io_thread_;
   scoped_refptr<base::SequencedTaskRunner> db_thread_;
   mutable scoped_ptr<QuotaDatabase> database_;
 
-  GetLRUOriginCallback lru_origin_callback_;
+  GetOriginCallback lru_origin_callback_;
   std::set<GURL> access_notified_origins_;
 
   QuotaClientList clients_;
 
   scoped_ptr<UsageTracker> temporary_usage_tracker_;
   scoped_ptr<UsageTracker> persistent_usage_tracker_;
   scoped_ptr<UsageTracker> syncable_usage_tracker_;
   // TODO(michaeln): Need a way to clear the cache, drop and
   // reinstantiate the trackers when they're not handling requests.
 
@@ skipping 32 matching lines @@
 
 struct QuotaManagerDeleter {
   static void Destruct(const QuotaManager* manager) {
     manager->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_