Hook up DomStorageArea with a DomStorageDatabase.

webkit/dom_storage/dom_storage_area.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_area.h"
 #include "webkit/dom_storage/dom_storage_map.h"
 #include "webkit/dom_storage/dom_storage_namespace.h"
+#include "webkit/fileapi/file_system_util.h"
 
 namespace dom_storage {
 
 DomStorageArea::DomStorageArea(
     int64 namespace_id, const GURL& origin,
     const FilePath& directory, DomStorageTaskRunner* task_runner)
     : namespace_id_(namespace_id), origin_(origin),
       directory_(directory), task_runner_(task_runner),
-      map_(new DomStorageMap()) {
+      map_(new DomStorageMap()),
+      backing_(NULL),
+      initial_import_done_(false),
+      clear_all_next_sync_(false) {
+
+  if (namespace_id == kLocalStorageNamespaceId && !directory.empty()) {
+    FilePath path = directory.Append(DatabaseFileNameFromOrigin(origin_));
+    backing_.reset(new DomStorageDatabase(path));
+  } else {
+    // Not a local storage area or no directory specified for backing
+    // database, (i.e. it's an incognito profile).
+    initial_import_done_ = true;
+  }
 }
 
 DomStorageArea::~DomStorageArea() {
 }
 
 unsigned DomStorageArea::Length() {
+  InitialImportIfNeeded();
   return map_->Length();
 }
 
 NullableString16 DomStorageArea::Key(unsigned index) {
+  InitialImportIfNeeded();
   return map_->Key(index);
 }
 
 NullableString16 DomStorageArea::GetItem(const string16& key) {
+  InitialImportIfNeeded();
   return map_->GetItem(key);
 }
 
 bool DomStorageArea::SetItem(
     const string16& key, const string16& value,
     NullableString16* old_value) {
+  InitialImportIfNeeded();
+
   if (!map_->HasOneRef())
     map_ = map_->DeepCopy();
-  return map_->SetItem(key, value, old_value);
+  bool success = map_->SetItem(key, value, old_value);
+  if (success && backing_.get()) {
+    items_to_sync_[key] = NullableString16(value, false);
+    SyncToBacking();
+  }
+  return success;
 }
 
 bool DomStorageArea::RemoveItem(
     const string16& key,
     string16* old_value) {
+  InitialImportIfNeeded();
   if (!map_->HasOneRef())
     map_ = map_->DeepCopy();
-  return map_->RemoveItem(key, old_value);
+  bool success = map_->RemoveItem(key, old_value);
+  if (success && backing_.get()) {
+    items_to_sync_[key] = NullableString16(true);
+    SyncToBacking();
+  }
+  return success;
 }
 
 bool DomStorageArea::Clear() {
+  InitialImportIfNeeded();
   if (map_->Length() == 0)
     return false;
+
   map_ = new DomStorageMap();
+
+  if (backing_.get()) {
+    items_to_sync_.clear();
+    clear_all_next_sync_ = true;
+    SyncToBacking();
+  }
+
   return true;
 }
 
 DomStorageArea* DomStorageArea::ShallowCopy(int64 destination_namespace_id) {
   DCHECK_NE(kLocalStorageNamespaceId, namespace_id_);
   DCHECK_NE(kLocalStorageNamespaceId, destination_namespace_id);
   // SessionNamespaces aren't backed by files on disk.
+  DCHECK(!backing_.get());
+
   DomStorageArea* copy = new DomStorageArea(destination_namespace_id, origin_,
                                             FilePath(), task_runner_);
   copy->map_ = map_;
   return copy;
 }
 
+void DomStorageArea::InitialImportIfNeeded() {
+  if (initial_import_done_)
+    return;
+
+  DCHECK_EQ(kLocalStorageNamespaceId, namespace_id_);
+  DCHECK(backing_.get());
+
+  ValuesMap initial_values;
+  backing_->ReadAllValues(&initial_values);
+  map_->SwapValues(&initial_values);
+  initial_import_done_ = true;
+}
+
+void DomStorageArea::SyncToBacking() {
+  DCHECK_EQ(kLocalStorageNamespaceId, namespace_id_);
+  DCHECK(backing_.get());
+
+  if (!clear_all_next_sync_ && items_to_sync_.empty())
+    return;
+
+  backing_->CommitChanges(clear_all_next_sync_, items_to_sync_);
+  clear_all_next_sync_ = false;
+  items_to_sync_.clear();
+}
+
+// static
+FilePath DomStorageArea::DatabaseFileNameFromOrigin(const GURL& origin) {
+  std::string filename = fileapi::GetOriginIdentifierFromURL(origin)
+      + ".localstorage";
+  return FilePath().AppendASCII(filename);
+}
+
 }  // namespace dom_storage