DomStorage data deletion and memory purging.

webkit/dom_storage/dom_storage_namespace.cc

 // Copyright (c) 2012 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 "webkit/dom_storage/dom_storage_namespace.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "webkit/dom_storage/dom_storage_area.h"
 #include "webkit/dom_storage/dom_storage_task_runner.h"
@@ skipping 46 matching lines @@
   DomStorageNamespace* clone =
       new DomStorageNamespace(clone_namespace_id, task_runner_);
   AreaMap::const_iterator it = areas_.begin();
   for (; it != areas_.end(); ++it) {
     DomStorageArea* area = it->second.area_->ShallowCopy(clone_namespace_id);
     clone->areas_[it->first] = AreaHolder(area, 0);
   }
   return clone;
 }
 
+void DomStorageNamespace::DeleteOrigin(const GURL& origin) {
+  AreaHolder* holder = GetAreaHolder(origin);
+  if (holder) {
+    holder->area_->DeleteOrigin();
+    return;
+  }
+  if (directory_.empty())
+    return;
+  scoped_refptr<DomStorageArea> area =
+      new DomStorageArea(namespace_id_, origin, directory_, task_runner_);
+  area->DeleteOrigin();
+}
+
 void DomStorageNamespace::PurgeMemory() {
-  // TODO(michaeln): write me
+  DCHECK_EQ(kLocalStorageNamespaceId, namespace_id_);
+  if (directory_.empty())
+    return;  // We can't purge w/o backing on disk.
+  AreaMap::const_iterator it = areas_.begin();
+  while (it != areas_.end()) {
+    // Leave it alone if changes are pending
+    if (it->second.area_->HasUncommittedChanges()) {
+      ++it;
+      continue;
+    }
+
+    // If not in use, we can shut it down and remove
+    // it from our collection entirely.
+    if (it->second.open_count_ == 0) {
+      it->second.area_->Shutdown();
+      AreaMap::const_iterator delete_it = it;

[jsbell, 2012/03/21 20:26:29]

Can you just do: areas_.erase(it++) ?

[michaeln, 2012/03/21 20:30:20]

looks like i could

[michaeln, 2012/03/21 20:46:10]

Done.

+      ++it;
+      areas_.erase(delete_it);
+      continue;
+    }
+
+    // Otherwise, we can clear caches and such.
+    it->second.area_->PurgeMemory();
+    ++it;
+  }
 }
 
 void DomStorageNamespace::Shutdown() {
   AreaMap::const_iterator it = areas_.begin();
   for (; it != areas_.end(); ++it)
     it->second.area_->Shutdown();
 }
 
 
 DomStorageNamespace::AreaHolder*
@@ skipping 12 matching lines @@
 
 DomStorageNamespace::AreaHolder::AreaHolder(
     DomStorageArea* area, int count)
     : area_(area), open_count_(count) {
 }
 
 DomStorageNamespace::AreaHolder::~AreaHolder() {
 }
 
 }  // namespace dom_storage