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Add xmldoc for RegisterForNotifications

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This commit is contained in:
Dean Herbert 2022-01-24 17:52:36 +09:00
parent abf14f0982
commit f4e7211ef1
1 changed files with 24 additions and 3 deletions
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27
osu.Game/Database/RealmContextFactory.cs
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@ -251,7 +251,28 @@ namespace osu.Game.Database
}
}
public IDisposable RegisterForNotifications<T>(Func<Realm, IQueryable<T>> query, NotificationCallbackDelegate<T> onChanged)
/// <summary>
/// Subscribe to a realm collection and begin watching for asynchronous changes.
/// </summary>
/// <remarks>
/// This adds osu! specific thread and managed state safety checks on top of <see cref="IRealmCollection{T}.SubscribeForNotifications"/>.
///
/// In addition to the documented realm behaviour, we have the additional requirement of handling subscriptions over potential context loss.
/// When this happens, callback events will be automatically fired:
/// - On context loss, a callback with an empty collection and <c>null</c> <see cref="ChangeSet"/> will be invoked.
/// - On context revival, a standard initial realm callback will arrive, with <c>null</c> <see cref="ChangeSet"/> and an up-to-date collection.
/// </remarks>
/// <param name="query">The <see cref="IQueryable{T}"/> to observe for changes.</param>
/// <typeparam name="T">Type of the elements in the list.</typeparam>
/// <seealso cref="IRealmCollection{T}.SubscribeForNotifications"/>
/// <param name="callback">The callback to be invoked with the updated <see cref="IRealmCollection{T}"/>.</param>
/// <returns>
/// A subscription token. It must be kept alive for as long as you want to receive change notifications.
/// To stop receiving notifications, call <see cref="IDisposable.Dispose"/>.
///
/// May be null in the case the provided collection is not managed.
/// </returns>
public IDisposable RegisterForNotifications<T>(Func<Realm, IQueryable<T>> query, NotificationCallbackDelegate<T> callback)
where T : RealmObjectBase
{
if (!ThreadSafety.IsUpdateThread)
@ -259,10 +280,10 @@ namespace osu.Game.Database
lock (contextLock)
{
Func<Realm, IDisposable?> action = realm => query(realm).QueryAsyncWithNotifications(onChanged);
Func<Realm, IDisposable?> action = realm => query(realm).QueryAsyncWithNotifications(callback);
// Store an action which is used when blocking to ensure consumers don't use results of a stale changeset firing.
realmSubscriptionsResetMap.Add(action, () => onChanged(new EmptyRealmSet<T>(), null, null));
realmSubscriptionsResetMap.Add(action, () => callback(new EmptyRealmSet<T>(), null, null));
return RegisterCustomSubscription(action);
}
}