sync: migrate invalidation state from syncable::Directory to InvalidationStorage

sync/notifier/invalidation_notifier.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 "sync/notifier/invalidation_notifier.h"
 
 #include "base/logging.h"
 #include "base/message_loop_proxy.h"
+#include "base/metrics/histogram.h"
 #include "jingle/notifier/base/const_communicator.h"
 #include "jingle/notifier/base/notifier_options_util.h"
 #include "net/url_request/url_request_context.h"
 #include "sync/notifier/sync_notifier_observer.h"
 #include "sync/syncable/model_type_payload_map.h"
 #include "talk/xmpp/jid.h"
 #include "talk/xmpp/xmppclientsettings.h"
 
 namespace sync_notifier {
 
 InvalidationNotifier::InvalidationNotifier(
     const notifier::NotifierOptions& notifier_options,
     const InvalidationVersionMap& initial_max_invalidation_versions,
+    const std::string& initial_invalidation_state,
     const browser_sync::WeakHandle<InvalidationStateTracker>&
         invalidation_state_tracker,
     const std::string& client_info)
     : state_(STOPPED),
       notifier_options_(notifier_options),
       initial_max_invalidation_versions_(initial_max_invalidation_versions),
       invalidation_state_tracker_(invalidation_state_tracker),
-      client_info_(client_info) {
+      client_info_(client_info),
+      invalidation_state_(initial_invalidation_state) {
   DCHECK_EQ(notifier::NOTIFICATION_SERVER,
             notifier_options.notification_method);
   DCHECK(notifier_options_.request_context_getter);
   // TODO(akalin): Replace NonThreadSafe checks with IO thread checks.
   DCHECK(notifier_options_.request_context_getter->GetIOMessageLoopProxy()->
       BelongsToCurrentThread());
 }
 
 InvalidationNotifier::~InvalidationNotifier() {
   DCHECK(non_thread_safe_.CalledOnValidThread());
 }
 
 void InvalidationNotifier::AddObserver(SyncNotifierObserver* observer) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   observers_.AddObserver(observer);
 }
 
 void InvalidationNotifier::RemoveObserver(SyncNotifierObserver* observer) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   observers_.RemoveObserver(observer);
 }
 
 void InvalidationNotifier::SetUniqueId(const std::string& unique_id) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   invalidation_client_id_ = unique_id;
   DVLOG(1) << "Setting unique ID to " << unique_id;
   CHECK(!invalidation_client_id_.empty());
 }
 
-void InvalidationNotifier::SetState(const std::string& state) {
+void InvalidationNotifier::SetStateDeprecated(const std::string& state) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
-  invalidation_state_ = state;
-  DVLOG(1) << "Setting new state";
+  DCHECK_LT(state_, STARTED);
+  if (invalidation_state_.empty()) {
+    // Migrate state from sync to invalidation state tracker (bug
+    // 124140).  We've just been handed state from the syncable::Directory, and
+    // the initial invalidation state was empty, implying we've never written
+    // to the new store. Do this here to ensure we always migrate (even if
+    // we fail to establish an initial connection or receive an initial
+    // invalidation) so that we can make the old code obsolete as soon as
+    // possible.
+    invalidation_state_ = state;
+    invalidation_state_tracker_.Call(
+        FROM_HERE, &InvalidationStateTracker::SetInvalidationState, state);
+    UMA_HISTOGRAM_BOOLEAN("InvalidationNotifier.UsefulSetState", true);
+  } else {
+    UMA_HISTOGRAM_BOOLEAN("InvalidationNotifier.UsefulSetState", false);
+  }
 }
 
 void InvalidationNotifier::UpdateCredentials(
     const std::string& email, const std::string& token) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   CHECK(!invalidation_client_id_.empty());
   DVLOG(1) << "Updating credentials for " << email;
   buzz::XmppClientSettings xmpp_client_settings =
       notifier::MakeXmppClientSettings(notifier_options_, email, token);
   if (state_ >= CONNECTING) {
@@ skipping 32 matching lines @@
   if (state_ >= STARTED) {
     invalidation_client_.ChangeBaseTask(base_task);
   } else {
     DVLOG(1) << "First time connecting: starting invalidation client with id "
              << invalidation_client_id_ << " and client info "
              << client_info_;
     invalidation_client_.Start(
         invalidation_client_id_, client_info_, invalidation_state_,
         initial_max_invalidation_versions_,
         invalidation_state_tracker_,
-        this, this, base_task);
+        this, base_task);
     invalidation_state_.clear();
     state_ = STARTED;
   }
 }
 
 void InvalidationNotifier::OnDisconnect() {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   DVLOG(1) << "OnDisconnect";
 }
 
 void InvalidationNotifier::OnInvalidate(
     const syncable::ModelTypePayloadMap& type_payloads) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   FOR_EACH_OBSERVER(SyncNotifierObserver, observers_,
                     OnIncomingNotification(type_payloads,
                                            sync_notifier::REMOTE_NOTIFICATION));
 }
 
 void InvalidationNotifier::OnSessionStatusChanged(bool has_session) {
   FOR_EACH_OBSERVER(SyncNotifierObserver, observers_,
                     OnNotificationStateChange(has_session));
 }
 
-void InvalidationNotifier::WriteState(const std::string& state) {
-  DCHECK(non_thread_safe_.CalledOnValidThread());
-  DVLOG(1) << "WriteState";
-  FOR_EACH_OBSERVER(SyncNotifierObserver, observers_, StoreState(state));
-}
-
 }  // namespace sync_notifier