cast_app_availability_tracker.h | Explore in Territory

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_MEDIA_ROUTER_PROVIDERS_CAST_CAST_APP_AVAILABILITY_TRACKER_H_
#define CHROME_BROWSER_MEDIA_ROUTER_PROVIDERS_CAST_CAST_APP_AVAILABILITY_TRACKER_H_

#include <string>
#include <vector>

#include "base/containers/flat_map.h"
#include "base/containers/flat_set.h"
#include "base/time/time.h"
#include "components/media_router/common/discovery/media_sink_internal.h"
#include "components/media_router/common/media_source.h"
#include "components/media_router/common/providers/cast/cast_media_source.h"
#include "components/media_router/common/providers/cast/channel/cast_device_capability.h"
#include "components/media_router/common/providers/cast/channel/cast_message_util.h"

namespace media_router {

// Tracks sink queries and their extracted Cast app IDs and their availabilities
// on discovered sinks.
// Example usage:
///
// (1) A page creates a PresentationRequest with URL "cast:foo". To register the
// source to be tracked:
//   CastAppAvailabilityTracker tracker;
//   auto source = CastMediaSource::From("cast:foo");
//   auto new_app_ids = tracker.RegisterSource(*source);
//
// (2) The set of app IDs returned by the tracker can then be used by the caller
// to send an app availability request to each of the discovered sinks.
//
// (3) Once the caller knows the availability value for a (sink, app) pair, it
// may inform the tracker to update its results:
//   auto affected_sources =
//       tracker.UpdateAppAvailability(sink_id, app_id, {availability, now});
//
// (4) The tracker returns a subset of discovered sources that were affected by
// the update. The caller can then call |GetAvailableSinks()| to get the updated
// results for each affected source.
//
// (5a): At any time, the caller may call |RemoveResultsForSink()| to remove
// cached results pertaining to the sink, when it detects that a sink is removed
// or no longer valid.
//
// (5b): At any time, the caller may call |GetAvailableSinks()| (even before the
// source is registered) to determine if there are cached results available.
class CastAppAvailabilityTracker { … };

}  // namespace media_router

#endif  // CHROME_BROWSER_MEDIA_ROUTER_PROVIDERS_CAST_CAST_APP_AVAILABILITY_TRACKER_H_
chromium/chrome/browser/media/router/providers/cast/cast_app_availability_tracker.h
