Persist sessionStorage on disk.

webkit/dom_storage/dom_storage_context.cc

Index: webkit/dom_storage/dom_storage_context.cc
diff --git a/webkit/dom_storage/dom_storage_context.cc b/webkit/dom_storage/dom_storage_context.cc
index e31019067cea7b9922f5e894dd30e741c1d0b5c9..9056c1ae8d9fcd9c819c834e2021f38cf2b21040 100644
--- a/webkit/dom_storage/dom_storage_context.cc
+++ b/webkit/dom_storage/dom_storage_context.cc
@@ -10,9 +10,11 @@
 #include "base/location.h"
 #include "base/time.h"
 #include "webkit/dom_storage/dom_storage_area.h"
+#include "webkit/dom_storage/dom_storage_database.h"
 #include "webkit/dom_storage/dom_storage_namespace.h"
 #include "webkit/dom_storage/dom_storage_task_runner.h"
 #include "webkit/dom_storage/dom_storage_types.h"
+#include "webkit/dom_storage/session_storage_database.h"
 #include "webkit/quota/special_storage_policy.h"
 
 using file_util::FileEnumerator;
@@ -38,6 +40,10 @@ DomStorageContext::DomStorageContext(
   // namespace ids at one since zero is reserved for the
   // kLocalStorageNamespaceId.
   session_id_sequence_.GetNext();
+  if (!sessionstorage_directory_.empty()) {
+    session_storage_database_ =
+        new SessionStorageDatabase(sessionstorage_directory_);
+  }
 }
 
 DomStorageContext::~DomStorageContext() {
@@ -87,6 +93,7 @@ void DomStorageContext::GetUsageInfo(std::vector<UsageInfo>* infos,
       infos->push_back(info);
     }
   }
+  // FIXME(marja): Get usage infos for sessionStorage (crbug.com/123599).
 }
 
 void DomStorageContext::DeleteOrigin(const GURL& origin) {
@@ -124,13 +131,25 @@ void DomStorageContext::Shutdown() {
   for (; it != namespaces_.end(); ++it)
     it->second->Shutdown();
 
+  // Delete data from sessionStorage. If the previous exit was unclean, the
+  // session storage backing might contain leftover data. Delete it now.
+  if (session_storage_database_.get()) {
+    bool success = task_runner_->PostShutdownBlockingTask(
+        FROM_HERE,
+        DomStorageTaskRunner::COMMIT_SEQUENCE,
+        base::Bind(&DomStorageContext::DeleteLeftoverDataInCommitSequence,
+                   this));
+    DCHECK(success);
+  }
+
+  // Delete data from localStorage.
   if (localstorage_directory_.empty())
     return;
 
   // Respect the content policy settings about what to
   // keep and what to discard.
-  if (save_session_state_)
-    return;  // Keep everything.
+  if (save_session_state_)  // Keep everything.
+    return;
 
   bool has_session_only_origins =
       special_storage_policy_.get() &&
@@ -192,13 +211,23 @@ void DomStorageContext::CreateSessionNamespace(
   DCHECK(namespace_id != kLocalStorageNamespaceId);
   DCHECK(namespaces_.find(namespace_id) == namespaces_.end());
   namespaces_[namespace_id] = new DomStorageNamespace(
-      namespace_id, task_runner_);
+      namespace_id, session_storage_database_.get(), task_runner_);
 }
 
 void DomStorageContext::DeleteSessionNamespace(
     int64 namespace_id) {
   DCHECK_NE(kLocalStorageNamespaceId, namespace_id);
   namespaces_.erase(namespace_id);
+  // TODO(marja): When doing a session restore, protect parts of the data from
+  // deletion.
+  if (session_storage_database_.get()) {
+    bool success = task_runner_->PostShutdownBlockingTask(
+        FROM_HERE,
+        DomStorageTaskRunner::COMMIT_SEQUENCE,
+        base::Bind(&DomStorageContext::DeleteSessionNamespaceInCommitSequence,
+                   this, namespace_id));
+    DCHECK(success);
+  }
 }
 
 void DomStorageContext::CloneSessionNamespace(
@@ -237,4 +266,22 @@ void DomStorageContext::ClearLocalStateInCommitSequence() {
   }
 }
 
+void DomStorageContext::DeleteSessionNamespaceInCommitSequence(
+    int64 namespace_id) {
+  session_storage_database_->DeleteNamespace(namespace_id);
+}
+
+void DomStorageContext::DeleteLeftoverDataInCommitSequence() {
+  DCHECK(session_storage_database_.get());
+  // Delete all namespaces which don't have an associated DomStorageNamespace
+  // alive.
+  std::vector<int64> namespace_ids;
+  session_storage_database_->ReadNamespaceIds(&namespace_ids);
+  for (std::vector<int64>::const_iterator it = namespace_ids.begin();
+       it != namespace_ids.end(); ++it) {
+    if (namespaces_.find(*it) == namespaces_.end())
+      session_storage_database_->DeleteNamespace(*it);
+  }
+}
+
 }  // namespace dom_storage