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 f9d530a65ecf751e44d90a5e83690fc2ce10b0e6..612d70a6c59c36b16dbce9e46fb88f2c6d109d54 100644
--- a/webkit/dom_storage/dom_storage_context.cc
+++ b/webkit/dom_storage/dom_storage_context.cc
@@ -9,10 +9,13 @@
 #include "base/file_util.h"
 #include "base/location.h"
 #include "base/time.h"
+#include "chrome/common/guid.h" // FIXME: layering violation?
 #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;
@@ -37,6 +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() {
@@ -86,6 +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) {
@@ -109,6 +117,18 @@ 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;
 
@@ -170,33 +190,69 @@ void DomStorageContext::NotifyAreaCleared(
       OnDomStorageAreaCleared(area, page_url));
 }
 
+std::string DomStorageContext::AllocatePersistentSessionId() {
+  std::string guid = guid::GenerateGUID();
+  std::replace(guid.begin(), guid.end(), '-', '_');
+  return guid;
+}
+
 void DomStorageContext::CreateSessionNamespace(
-    int64 namespace_id) {
+    int64 namespace_id,
+    const std::string& persistent_namespace_id) {
   if (is_shutdown_)
     return;
   DCHECK(namespace_id != kLocalStorageNamespaceId);
   DCHECK(namespaces_.find(namespace_id) == namespaces_.end());
   namespaces_[namespace_id] = new DomStorageNamespace(
-      namespace_id, task_runner_);
+      namespace_id, persistent_namespace_id, session_storage_database_.get(),
+      task_runner_);
 }
 
 void DomStorageContext::DeleteSessionNamespace(
     int64 namespace_id) {
   DCHECK_NE(kLocalStorageNamespaceId, namespace_id);
+  StorageNamespaceMap::const_iterator it = namespaces_.find(namespace_id);
+  if (it == namespaces_.end())
+    return;
+  std::string persistent_namespace_id = it->second->persistent_namespace_id();
+  if (session_storage_database_.get()) {
+    if (doomed_persistent_session_ids_.find(persistent_namespace_id) !=
+        doomed_persistent_session_ids_.end()) {
+      bool success = task_runner_->PostShutdownBlockingTask(
+          FROM_HERE,
+          DomStorageTaskRunner::COMMIT_SEQUENCE,
+          base::Bind(
+              base::IgnoreResult(&SessionStorageDatabase::DeleteNamespace),
+              session_storage_database_,
+              persistent_namespace_id));
+      DCHECK(success);
+    } else {
+      // Protect the persistent namespace ID from leftover data deletion
+      // (DeleteLeftoverDataInCommitSequence).
+      protected_persistent_session_ids_.insert(persistent_namespace_id);
+    }
+  }
   namespaces_.erase(namespace_id);
+  doomed_persistent_session_ids_.erase(persistent_namespace_id);
 }
 
 void DomStorageContext::CloneSessionNamespace(
-    int64 existing_id, int64 new_id) {
+    int64 existing_id, int64 new_id,
+    const std::string& new_persistent_id) {
   if (is_shutdown_)
     return;
   DCHECK_NE(kLocalStorageNamespaceId, existing_id);
   DCHECK_NE(kLocalStorageNamespaceId, new_id);
   StorageNamespaceMap::iterator found = namespaces_.find(existing_id);
   if (found != namespaces_.end())
-    namespaces_[new_id] = found->second->Clone(new_id);
+    namespaces_[new_id] = found->second->Clone(new_id, new_persistent_id);
   else
-    CreateSessionNamespace(new_id);
+    CreateSessionNamespace(new_id, new_persistent_id);
+}
+
+void DomStorageContext::DoomSessionStorage(
+    const std::string& persistent_namespace_id) {
+  doomed_persistent_session_ids_.insert(persistent_namespace_id);
 }
 
 void DomStorageContext::ClearSessionOnlyOrigins() {
@@ -220,4 +276,24 @@ void DomStorageContext::ClearSessionOnlyOrigins() {
   }
 }
 
+void DomStorageContext::DeleteLeftoverDataInCommitSequence() {
+  DCHECK(session_storage_database_.get());
+  // Delete all namespaces which don't have an associated DomStorageNamespace
+  // alive.
+  std::set<std::string> namespace_ids_in_use;
+  for (StorageNamespaceMap::const_iterator it = namespaces_.begin();
+       it != namespaces_.end(); ++it)
+    namespace_ids_in_use.insert(it->second->persistent_namespace_id());
+
+  std::vector<std::string> namespace_ids;
+  session_storage_database_->ReadNamespaceIds(&namespace_ids);
+  for (std::vector<std::string>::const_iterator it = namespace_ids.begin();
+       it != namespace_ids.end(); ++it) {
+    if (namespace_ids_in_use.find(*it) == namespace_ids_in_use.end() &&
+        protected_persistent_session_ids_.find(*it) ==
+        protected_persistent_session_ids_.end())
+      session_storage_database_->DeleteNamespace(*it);
+  }
+}
+
 }  // namespace dom_storage