Add access count and time-since-accessed histograms to temp storage eviction.

storage/browser/quota/quota_manager.cc

 // 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.
 
 #include "storage/browser/quota/quota_manager.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/bind.h"
@@ skipping 58 matching lines @@
 // TODO(kinuko): This should be like 10% of the actual disk space.
 // For now we simply use a constant as getting the disk size needs
 // platform-dependent code. (http://crbug.com/178976)
 int64 QuotaManager::kMinimumPreserveForSystem = 1024 * kMBytes;
 
 const int QuotaManager::kEvictionIntervalInMilliSeconds =
     30 * kMinutesInMilliSeconds;
 
 const char QuotaManager::kTimeBetweenRepeatedOriginEvictionsHistogram[] =
     "Quota.TimeBetweenRepeatedOriginEvictions";
+const char QuotaManager::kEvictedOriginAccessedCountHistogram[] =
+    "Quota.EvictedOriginAccessCount";
+const char QuotaManager::kEvictedOriginTimeSinceAccessHistogram[] =
+    "Quota.EvictedOriginTimeSinceAccess";
 
 // Heuristics: assuming average cloud server allows a few Gigs storage
 // on the server side and the storage needs to be shared for user data
 // and by multiple apps.
 int64 QuotaManager::kSyncableStorageDefaultHostQuota = 500 * kMBytes;
 
 namespace {
 
 void CountOriginType(const std::set<GURL>& origins,
                      SpecialStoragePolicy* policy,
@@ skipping 63 matching lines @@
   DCHECK(database);
   database->GetLRUOrigin(type, exceptions, policy, url);
   return true;
 }
 
 bool DeleteOriginInfoOnDBThread(const GURL& origin,
                                 StorageType type,
                                 bool is_eviction,
                                 QuotaDatabase* database) {
   DCHECK(database);
+
+  base::Time now = base::Time::Now();
+
+  if (is_eviction) {
+    QuotaDatabase::OriginInfoTableEntry entry;
+    database->GetOriginInfo(origin, type, &entry);
+    UMA_HISTOGRAM_COUNTS(QuotaManager::kEvictedOriginAccessedCountHistogram,
+                         entry.used_count);
+    UMA_HISTOGRAM_LONG_TIMES(
+        QuotaManager::kEvictedOriginTimeSinceAccessHistogram,
+        now - entry.last_access_time);
+  }
+
   if (!database->DeleteOriginInfo(origin, type))
     return false;
 
   // If the deletion is not due to an eviction, delete the entry in the eviction
   // table as well due to privacy concerns.
   if (!is_eviction)
     return database->DeleteOriginLastEvictionTime(origin, type);
 
   base::Time last_eviction_time;
-  if (!database->GetOriginLastEvictionTime(origin, type, &last_eviction_time))
-    return false;
+  database->GetOriginLastEvictionTime(origin, type, &last_eviction_time);
 
-  base::Time now = base::Time::Now();
   if (last_eviction_time != base::Time()) {
     UMA_HISTOGRAM_LONG_TIMES(
         QuotaManager::kTimeBetweenRepeatedOriginEvictionsHistogram,
         now - last_eviction_time);
   }
 
   return database->SetOriginLastEvictionTime(origin, type, now);
 }
 
 bool InitializeTemporaryOriginsInfoOnDBThread(const std::set<GURL>* origins,
@@ skipping 1547 matching lines @@
   // |database_|, therefore we can be sure that database_ is alive when this
   // task runs.
   base::PostTaskAndReplyWithResult(
       db_thread_.get(),
       from_here,
       base::Bind(task, base::Unretained(database_.get())),
       reply);
 }
 
 }  // namespace storage