/// <summary>
/// Presense grain calls this method to update the game with its latest status
/// </summary>
public async Task UpdateGameStatus(GameStatus status)
{
this.status = status;
// Check for new players that joined since last update
foreach(Guid player in status.Players)
if(!players.Contains(player))
{
try
{
// Here we call player grains serially, which is less efficient than a fan-out but simpler to express.
await GrainFactory.GetGrain<IPlayerGrain>(player).JoinGame(this);
players.Add(player);
}
catch (Exception)
{
// Ignore exceptions while telling player grains to join the game.
// Since we didn't add the player to the list, this will be tried again with next update.
}
}
// Check for players that left the game since last update
List<Task> promises = new List<Task>();
foreach(Guid player in players)
if (!status.Players.Contains(player))
{
try
{
// Here we do a fan-out with multiple calls going out in parallel. We join the promisses later.
// More code to write but we get lower latency when calling multiple player grains.
promises.Add(GrainFactory.GetGrain<IPlayerGrain>(player).LeaveGame(this));
players.Remove(player);
}
catch (Exception)
{
// Ignore exceptions while telling player grains to leave the game.
// Since we didn't remove the player from the list, this will be tried again with next update.
}
}
// Joining promises
await Task.WhenAll(promises);
// Notify subsribers about the latest game score
subscribers.Notify((s) => s.UpdateGameScore(status.Score));
return;
}
public HeartbeatData()
{
Status = new GameStatus();
}
public HeartbeatData()
{
Status = new GameStatus();
}