Pref service: Batch pref updates.

services/preferences/public/interfaces/preferences.mojom

 // Copyright 2016 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.
 
 module prefs.mojom;
 
 import "mojo/common/values.mojom";
 import "services/preferences/public/interfaces/preferences_configuration.mojom";
 
 const string kServiceName = "preferences";
 const string kForwarderServiceName = "preferences_forwarder";
 
 // The know pref store types.
 //
 // Should be kept in sync with PrefValueStore::PrefStoreType.
 enum PrefStoreType {
   MANAGED,
   SUPERVISED_USER,
   EXTENSION,
   COMMAND_LINE,
   USER,
   RECOMMENDED,
   DEFAULT,
 };
 
 // Allows observing changes to prefs stored in a |PrefStore|.
 interface PrefStoreObserver {
-  // The preference with the given |key| has changed. If |value| is null then
-  // the preference was deleted.
-  OnPrefChanged(string key, mojo.common.mojom.Value? value);
+  // Preferences have been changed.

[tibell, 2017/04/07 03:53:16]

Preferences that have changed.

[Sam McNally, 2017/04/07 05:24:02]

Acknowledged.

+  OnPrefsChanged(array<PrefUpdate> updates);
 
   // The PrefStore has been initialized (asynchronously).
   OnInitializationCompleted(bool succeeded);
 };
 
 // Captures the connections to a PrefStore by supplying the initial state of the
 // store and a handle to receive notifications on.
 struct PrefStoreConnection {
   // Handle to receive updates on.
   PrefStoreObserver& observer;
@@ skipping 52 matching lines @@
   // be received. The client asserts that it is already connected to the
   // |already_connected_types| pref stores through some other means, so the
   // Connect call will not connect to those.
   [Sync]
   Connect(PrefRegistry pref_registry,
           array<PrefStoreType> already_connected_types) =>
       (PersistentPrefStoreConnection connection,
        map<PrefStoreType, PrefStoreConnection> connections);
 };
 
+// An update to a pref.
+struct PrefUpdate {
+  // The key of the pref being updated.
+  string key;

[tibell, 2017/04/07 03:53:16]

This is still a normal pref key right? It doesn't contain paths into
DictionaryValues being updated or some such?

[Sam McNally, 2017/04/07 05:24:02]

Correct.

+  // The new value; a null |value| indicates a delete.
+  mojo.common.mojom.Value? value;
+  //|flags| is a bitmask of WritablePrefStore::PrefWriteFlags.
+  uint32 flags;
+};
+
 // An interface providing mutation access to a PersistentPrefStore.
 interface PersistentPrefStore {
-  // Sets the value for |key|. A null |value| indicates a delete. |flags| is a
-  // bitmask of WritablePrefStore::PrefWriteFlags.
-  SetValue(string key, mojo.common.mojom.Value? value, uint32 flags);
+  // Sets the values for prefs.
+  SetValues(array<PrefUpdate> updates);
 
   // These mirror the C++ PersistentPrefStore methods.
   CommitPendingWrite();
   SchedulePendingLossyWrites();
   ClearMutableValues();
 };
 
 // A registry of all prefs registered by a single client.
 struct PrefRegistry {
   map<string, PrefRegistration> registrations;
 };
 
 struct PrefRegistration {
   mojo.common.mojom.Value default_value;
 
   // A bitfield of flags. Flag values are defined in
   // PrefRegistry::PrefRegistrationFlags and
   // PrefRegistrySyncable::PrefRegistrationFlags.
   uint32 flags;
 };
 
 interface PrefServiceControl {
   // Initializes the pref service. This must be called before the service can
   // be used.
   Init(PersistentPrefStoreConfiguration configuration);
 };