gecko-dev/dom/localstorage/PBackgroundLSObserver.ipdl

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

include protocol PBackground;

include PBackgroundSharedTypes;

include "mozilla/dom/localstorage/SerializationHelpers.h";

using mozilla::dom::LSValue
  from "mozilla/dom/LSValue.h";

namespace mozilla {
namespace dom {

/**
 * The observer protocol sends "storage" event notifications for changes to
 * LocalStorage that take place in other processes as their Snapshots are
 * Checkpointed to the canonical Datastore in the parent process.  Same-process
 * notifications are generated as mutations happen.
 *
 * Note that mutations are never generated for redundant mutations.  Setting the
 * key "foo" to have value "bar" when it already has value "bar" will never
 * result in a "storage" event.
 */
async protocol PBackgroundLSObserver
{
  manager PBackground;

parent:
  /**
   * Sent by the LSObserver's destructor when it's going away.  Any Observe
   * messages received after this is sent will be ignored.  Which is fine,
   * because there should be nothing around left to hear.  In the event a new
   * page came into existence, its Observer creation will happen (effectively)
   * synchronously.
   */
  async DeleteMe();

child:
  /**
   * Only sent by the parent in response to a deletion request.
   */
  async __delete__();

  /**
   * Sent by the parent process as Snapshots from other processes are
   * Checkpointed, applying their mutations.  The child actor currently directly
   * shunts these to Storage::NotifyChange to generate "storage" events for
   * immediate dispatch.
   */
  async Observe(PrincipalInfo principalInfo,
                uint32_t privateBrowsingId,
                nsString documentURI,
                nsString key,
                LSValue oldValue,
                LSValue newValue);
};

} // namespace dom
} // namespace mozilla