Framing for a DOMStorage backend that does not depend on in-process-webkit.

webkit/dom_storage/dom_storage_context.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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/in_process_webkit/dom_storage_context.h"
-
-#include <algorithm>
+#include "webkit/dom_storage/dom_storage_context.h"
 
 #include "base/bind.h"
-#include "base/file_path.h"
-#include "base/file_util.h"
-#include "base/string_util.h"
-#include "content/browser/in_process_webkit/dom_storage_area.h"
-#include "content/browser/in_process_webkit/dom_storage_namespace.h"
-#include "content/browser/in_process_webkit/webkit_context.h"
-#include "content/common/dom_storage_common.h"
-#include "content/public/browser/browser_thread.h"
-#include "third_party/WebKit/Source/WebKit/chromium/public/WebSecurityOrigin.h"
-#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
-#include "webkit/glue/webkit_glue.h"
+#include "base/bind_helpers.h"
+#include "base/time.h"
+#include "webkit/dom_storage/dom_storage_task_runner.h"
 #include "webkit/quota/special_storage_policy.h"
 
-using content::BrowserThread;
+namespace dom_storage {
 
-using WebKit::WebSecurityOrigin;
-
-namespace {
-
-void ClearLocalState(const FilePath& domstorage_path,
-                     quota::SpecialStoragePolicy* special_storage_policy,
-                     bool clear_all_databases) {
-  file_util::FileEnumerator file_enumerator(
-      domstorage_path, false, file_util::FileEnumerator::FILES);
-  for (FilePath file_path = file_enumerator.Next(); !file_path.empty();
-       file_path = file_enumerator.Next()) {
-    if (file_path.Extension() == DOMStorageContext::kLocalStorageExtension) {
-      GURL origin(WebSecurityOrigin::createFromDatabaseIdentifier(
-          webkit_glue::FilePathToWebString(file_path.BaseName())).toString());
-      if (special_storage_policy->IsStorageProtected(origin))
-        continue;
-      if (!clear_all_databases &&
-          !special_storage_policy->IsStorageSessionOnly(origin)) {
-        continue;
-      }
-      file_util::Delete(file_path, false);
-    }
-  }
+DomStorageContext::DomStorageContext(
+    const FilePath& directory,
+    quota::SpecialStoragePolicy* special_storage_policy,
+    DomStorageTaskRunner* task_runner)
+    : directory_(directory),
+      special_storage_policy_(special_storage_policy),
+      task_runner_(task_runner),
+      clear_local_state_on_exit_(false),
+      save_session_state_(false) {
 }
 
-}  // namespace
-
-const FilePath::CharType DOMStorageContext::kLocalStorageDirectory[] =
-    FILE_PATH_LITERAL("Local Storage");
-
-const FilePath::CharType DOMStorageContext::kLocalStorageExtension[] =
-    FILE_PATH_LITERAL(".localstorage");
-
-DOMStorageContext::DOMStorageContext(
-    WebKitContext* webkit_context,
-    quota::SpecialStoragePolicy* special_storage_policy)
-    : last_storage_area_id_(0),
-      last_session_storage_namespace_id_on_ui_thread_(kLocalStorageNamespaceId),
-      last_session_storage_namespace_id_on_io_thread_(kLocalStorageNamespaceId),
-      clear_local_state_on_exit_(false),
-      save_session_state_(false),
-      special_storage_policy_(special_storage_policy) {
-  data_path_ = webkit_context->data_path();
+DomStorageContext::~DomStorageContext() {
 }
 
-DOMStorageContext::~DOMStorageContext() {
-  // This should not go away until all DOM Storage message filters have gone
-  // away.  And they remove themselves from this list.
-  DCHECK(message_filter_set_.empty());
-
-  for (StorageNamespaceMap::iterator iter(storage_namespace_map_.begin());
-       iter != storage_namespace_map_.end(); ++iter) {
-    delete iter->second;
-  }
-
-  if (save_session_state_)
-    return;
-
-  bool has_session_only_databases =
-      special_storage_policy_.get() &&
-      special_storage_policy_->HasSessionOnlyOrigins();
-
-  // Clearning only session-only databases, and there are none.
-  if (!clear_local_state_on_exit_ && !has_session_only_databases)
-    return;
-
-  // Not being on the WEBKIT thread here means we are running in a unit test
-  // where no clean up is needed.
-  if (BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED)) {
-    ClearLocalState(data_path_.Append(kLocalStorageDirectory),
-                    special_storage_policy_,
-                    clear_local_state_on_exit_);
-  }
+void DomStorageContext::AddEventObserver(EventObserver* observer) {
+  event_observers_.AddObserver(observer);
 }
 
-int64 DOMStorageContext::AllocateStorageAreaId() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  return ++last_storage_area_id_;
+void DomStorageContext::RemoveEventObserver(EventObserver* observer) {
+  event_observers_.RemoveObserver(observer);
 }
 
-int64 DOMStorageContext::AllocateSessionStorageNamespaceId() {
-  if (BrowserThread::CurrentlyOn(BrowserThread::UI))
-    return ++last_session_storage_namespace_id_on_ui_thread_;
-  return --last_session_storage_namespace_id_on_io_thread_;
+void DomStorageContext::NotifyItemSet(
+    DomStorageArea* area,
+    const string16& key,
+    const string16& new_value,
+    const NullableString16& old_value,
+    const GURL& page_url) {
+  FOR_EACH_OBSERVER(
+      EventObserver, event_observers_,
+      OnDomStorageItemSet(area, key, new_value, old_value, page_url));
 }
 
-int64 DOMStorageContext::CloneSessionStorage(int64 original_id) {
-  DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  int64 clone_id = AllocateSessionStorageNamespaceId();
-  BrowserThread::PostTask(
-      BrowserThread::WEBKIT_DEPRECATED, FROM_HERE,
-      base::Bind(&DOMStorageContext::CompleteCloningSessionStorage, this,
-                 original_id, clone_id));
-  return clone_id;
+void DomStorageContext::NotifyItemRemoved(
+    DomStorageArea* area,
+    const string16& key,
+    const string16& old_value,
+    const GURL& page_url) {
+  FOR_EACH_OBSERVER(
+      EventObserver, event_observers_,
+      OnDomStorageItemRemoved(area, key, old_value, page_url));
 }
 
-void DOMStorageContext::RegisterStorageArea(DOMStorageArea* storage_area) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  int64 id = storage_area->id();
-  DCHECK(!GetStorageArea(id));
-  storage_area_map_[id] = storage_area;
+void DomStorageContext::NotifyAreaCleared(
+    DomStorageArea* area,
+    const GURL& page_url) {
+  FOR_EACH_OBSERVER(
+      EventObserver, event_observers_,
+      OnDomStorageAreaCleared(area, page_url));
 }
 
-void DOMStorageContext::UnregisterStorageArea(DOMStorageArea* storage_area) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  int64 id = storage_area->id();
-  DCHECK(GetStorageArea(id));
-  storage_area_map_.erase(id);
+DomStorageNamespace* DomStorageContext::GetStorageNamespace(int64 namespace_id) {
+  return NULL;
 }
 
-DOMStorageArea* DOMStorageContext::GetStorageArea(int64 id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  StorageAreaMap::iterator iter = storage_area_map_.find(id);
-  if (iter == storage_area_map_.end())
-    return NULL;
-  return iter->second;
+int64 DomStorageContext::CreateSessionStorageNamespace() {
+  int64 new_id = session_storage_id_sequence_.GetNext() + 1;
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DomStorageContext::CreateSessionStorageNamespaceHelper,
+                 this, new_id));
+  return new_id;
 }
 
-void DOMStorageContext::DeleteSessionStorageNamespace(int64 namespace_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  StorageNamespaceMap::iterator iter =
-      storage_namespace_map_.find(namespace_id);
-  if (iter == storage_namespace_map_.end())
-    return;
-  DCHECK(iter->second->dom_storage_type() == DOM_STORAGE_SESSION);
-  delete iter->second;
-  storage_namespace_map_.erase(iter);
+void DomStorageContext::DeleteSessionStorageNamespace(int64 namespace_id) {
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DomStorageContext::DeleteSessionStorageNamespaceHelper,
+                 this, namespace_id));
 }
 
-DOMStorageNamespace* DOMStorageContext::GetStorageNamespace(
-    int64 id, bool allocation_allowed) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  StorageNamespaceMap::iterator iter = storage_namespace_map_.find(id);
-  if (iter != storage_namespace_map_.end())
-    return iter->second;
-  if (!allocation_allowed)
-    return NULL;
-  if (id == kLocalStorageNamespaceId)
-    return CreateLocalStorage();
-  return CreateSessionStorage(id);
+int64 DomStorageContext::CloneSessionStorageNamespace(int64 existing_id) {
+  int64 new_id = session_storage_id_sequence_.GetNext() + 1;
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DomStorageContext::CloneSessionStorageNamespaceHelper,
+                 this, existing_id, new_id));
+  return new_id;
 }
 
-void DOMStorageContext::RegisterMessageFilter(
-    DOMStorageMessageFilter* message_filter) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(message_filter_set_.find(message_filter) ==
-         message_filter_set_.end());
-  message_filter_set_.insert(message_filter);
+void DomStorageContext::CreateSessionStorageNamespaceHelper(
+    int64 new_id) {
 }
 
-void DOMStorageContext::UnregisterMessageFilter(
-    DOMStorageMessageFilter* message_filter) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(message_filter_set_.find(message_filter) !=
-         message_filter_set_.end());
-  message_filter_set_.erase(message_filter);
+void DomStorageContext::DeleteSessionStorageNamespaceHelper(
+    int64 namespace_id) {
 }
 
-const DOMStorageContext::MessageFilterSet*
-DOMStorageContext::GetMessageFilterSet() const {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  return &message_filter_set_;
+void DomStorageContext::CloneSessionStorageNamespaceHelper(
+    int64 existing_id, int64 new_id) {
 }
 
-void DOMStorageContext::PurgeMemory() {
-  // It is only safe to purge the memory from the LocalStorage namespace,
-  // because it is backed by disk and can be reloaded later.  If we purge a
-  // SessionStorage namespace, its data will be gone forever, because it isn't
-  // currently backed by disk.
-  DOMStorageNamespace* local_storage =
-      GetStorageNamespace(kLocalStorageNamespaceId, false);
-  if (local_storage)
-    local_storage->PurgeMemory();
-}
+}  // namespace dom_storage
 
-void DOMStorageContext::DeleteDataModifiedSince(const base::Time& cutoff) {
-  // Make sure that we don't delete a database that's currently being accessed
-  // by unloading all of the databases temporarily.
-  PurgeMemory();
-
-  file_util::FileEnumerator file_enumerator(
-      data_path_.Append(kLocalStorageDirectory), false,
-      file_util::FileEnumerator::FILES);
-  for (FilePath path = file_enumerator.Next(); !path.value().empty();
-       path = file_enumerator.Next()) {
-    GURL origin(WebSecurityOrigin::createFromDatabaseIdentifier(
-        webkit_glue::FilePathToWebString(path.BaseName())).toString());
-    if (special_storage_policy_->IsStorageProtected(origin))
-      continue;
-
-    file_util::FileEnumerator::FindInfo find_info;
-    file_enumerator.GetFindInfo(&find_info);
-    if (file_util::HasFileBeenModifiedSince(find_info, cutoff))
-      file_util::Delete(path, false);
-  }
-}
-
-void DOMStorageContext::DeleteLocalStorageFile(const FilePath& file_path) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-
-  // Make sure that we don't delete a database that's currently being accessed
-  // by unloading all of the databases temporarily.
-  // TODO(bulach): both this method and DeleteDataModifiedSince could purge
-  // only the memory used by the specific file instead of all memory at once.
-  // See http://crbug.com/32000
-  PurgeMemory();
-  file_util::Delete(file_path, false);
-}
-
-void DOMStorageContext::DeleteLocalStorageForOrigin(const string16& origin_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  DeleteLocalStorageFile(GetLocalStorageFilePath(origin_id));
-}
-
-void DOMStorageContext::DeleteAllLocalStorageFiles() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-
-  // Make sure that we don't delete a database that's currently being accessed
-  // by unloading all of the databases temporarily.
-  PurgeMemory();
-
-  file_util::FileEnumerator file_enumerator(
-      data_path_.Append(kLocalStorageDirectory), false,
-      file_util::FileEnumerator::FILES);
-  for (FilePath file_path = file_enumerator.Next(); !file_path.empty();
-       file_path = file_enumerator.Next()) {
-    if (file_path.Extension() == kLocalStorageExtension)
-      file_util::Delete(file_path, false);
-  }
-}
-
-DOMStorageNamespace* DOMStorageContext::CreateLocalStorage() {
-  FilePath dir_path;
-  if (!data_path_.empty())
-    dir_path = data_path_.Append(kLocalStorageDirectory);
-  DOMStorageNamespace* new_namespace =
-      DOMStorageNamespace::CreateLocalStorageNamespace(this, dir_path);
-  RegisterStorageNamespace(new_namespace);
-  return new_namespace;
-}
-
-DOMStorageNamespace* DOMStorageContext::CreateSessionStorage(
-    int64 namespace_id) {
-  DOMStorageNamespace* new_namespace =
-      DOMStorageNamespace::CreateSessionStorageNamespace(this, namespace_id);
-  RegisterStorageNamespace(new_namespace);
-  return new_namespace;
-}
-
-void DOMStorageContext::RegisterStorageNamespace(
-    DOMStorageNamespace* storage_namespace) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  int64 id = storage_namespace->id();
-  DCHECK(!GetStorageNamespace(id, false));
-  storage_namespace_map_[id] = storage_namespace;
-}
-
-/* static */
-void DOMStorageContext::CompleteCloningSessionStorage(
-    DOMStorageContext* context, int64 existing_id, int64 clone_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
-  DOMStorageNamespace* existing_namespace =
-      context->GetStorageNamespace(existing_id, false);
-  // If nothing exists, then there's nothing to clone.
-  if (existing_namespace)
-    context->RegisterStorageNamespace(existing_namespace->Copy(clone_id));
-}
-
-FilePath DOMStorageContext::GetLocalStorageFilePath(
-    const string16& origin_id) const {
-  FilePath storageDir = data_path_.Append(
-      DOMStorageContext::kLocalStorageDirectory);
-  FilePath::StringType id =
-      webkit_glue::WebStringToFilePathString(origin_id);
-  return storageDir.Append(id.append(kLocalStorageExtension));
-}