Persist sessionStorage on disk.

content/browser/dom_storage/dom_storage_context_impl.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 "content/browser/dom_storage/dom_storage_context_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_path.h"
 #include "base/message_loop_proxy.h"
 #include "content/browser/dom_storage/session_storage_namespace_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "webkit/dom_storage/dom_storage_area.h"
 #include "webkit/dom_storage/dom_storage_context.h"
 #include "webkit/dom_storage/dom_storage_task_runner.h"
 
 using content::BrowserThread;
 using content::DOMStorageContext;
 using dom_storage::DomStorageArea;
 using dom_storage::DomStorageContext;
 using dom_storage::DomStorageTaskRunner;
 using dom_storage::DomStorageWorkerPoolTaskRunner;
 
 namespace {
 
 const char kLocalStorageDirectory[] = "Local Storage";
+const char kSessionStorageDirectory[] = "Session Storage";
 
 void InvokeUsageInfoCallbackHelper(
       const DOMStorageContext::GetUsageInfoCallback& callback,
       const std::vector<DomStorageContext::UsageInfo>* infos) {
   callback.Run(*infos);
 }
 
 void GetUsageInfoHelper(
       base::MessageLoopProxy* reply_loop,
       DomStorageContext* context,
       const DOMStorageContext::GetUsageInfoCallback& callback) {
   std::vector<DomStorageContext::UsageInfo>* infos =
       new std::vector<DomStorageContext::UsageInfo>;
   context->GetUsageInfo(infos, true);
   reply_loop->PostTask(
       FROM_HERE,
       base::Bind(&InvokeUsageInfoCallbackHelper,
                  callback, base::Owned(infos)));
 }
 
 }  // namespace
 
 DOMStorageContextImpl::DOMStorageContextImpl(
     const FilePath& data_path,
-    quota::SpecialStoragePolicy* special_storage_policy) {
+    quota::SpecialStoragePolicy* special_storage_policy,
+    bool save_session_storage_on_disk) {
   base::SequencedWorkerPool* worker_pool = BrowserThread::GetBlockingPool();
-  // TODO(marja): Pass a nonempty session storage directory when session storage
-  // is backed on disk.
   context_ = new dom_storage::DomStorageContext(
       data_path.empty() ?
           data_path : data_path.AppendASCII(kLocalStorageDirectory),
-      FilePath(),  // Empty session storage directory.
+      (data_path.empty() || !save_session_storage_on_disk) ?
+          FilePath() : data_path.AppendASCII(kSessionStorageDirectory),
       special_storage_policy,
       new DomStorageWorkerPoolTaskRunner(
           worker_pool,
           worker_pool->GetNamedSequenceToken("dom_storage_primary"),
           worker_pool->GetNamedSequenceToken("dom_storage_commit"),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)));
 }
 
 DOMStorageContextImpl::~DOMStorageContextImpl() {
 }
@@ skipping 16 matching lines @@
       base::Bind(&DomStorageContext::DeleteOrigin, context_, origin));
 }
 
 scoped_refptr<content::SessionStorageNamespace>
 DOMStorageContextImpl::RecreateSessionStorage(
     const std::string& persistent_id) {
   return scoped_refptr<content::SessionStorageNamespace>(
       new SessionStorageNamespaceImpl(this, persistent_id));
 }
 
+void DOMStorageContextImpl::StartScavengingUnusedSessionStorage() {
+  DCHECK(context_);

[jam, 2012/07/11 15:51:35]

nit: dcheck is unnecessary, if it's NULL, the next line will be just as good of
a signal

[marja, 2012/07/12 09:22:03]

In all other funcs in this file there is DCHECK(context_) -> kept this.

+  context_->task_runner()->PostShutdownBlockingTask(
+      FROM_HERE,
+      DomStorageTaskRunner::PRIMARY_SEQUENCE,
+      base::Bind(&DomStorageContext::StartScavengingUnusedSessionStorage,
+                 context_));
+}
+
 void DOMStorageContextImpl::PurgeMemory() {
   DCHECK(context_);
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE,
       DomStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&DomStorageContext::PurgeMemory, context_));
 }
 
 void DOMStorageContextImpl::SetForceKeepSessionState() {
   DCHECK(context_);
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE,
       DomStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&DomStorageContext::SetForceKeepSessionState, context_));
 }
 
 void DOMStorageContextImpl::Shutdown() {
   DCHECK(context_);
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE,
       DomStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&DomStorageContext::Shutdown, context_));
 }