public ChannelReader <IEnumerable <RedditEntry> > Feed(string feedId)
{
var channel = Channel.CreateUnbounded <IEnumerable <RedditEntry> >();
var connection = new HubConnectionState
{
ConnectionId = Context.ConnectionId,
FeedId = feedId,
StreamChannel = channel,
};
if (_feedService.TryGetFeed(feedId, out var feed))
{
var data = feed.GetData();
if (data.Count() > 0)
{
_ = connection.StreamChannel.Writer.WriteAsync(data);
connection.LastEntryName = feed.LastEntryName;
}
}
else
{
_feedService.AddFeed(feedId, new RedditFeed
{
Id = feedId
});
}
_stateService.AddConnection(connection);
return(channel.Reader);
}
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
do
{
try
{
foreach (var feed in _feedService.GetAll())
{
var subreddit = feed.Id;
var listing = await _apiService.GetNew(subreddit : subreddit, limit : 10);
if (listing.Children.Count > 0)
{
_logger.LogInformation("Pushing new data from {0}: {1}",
subreddit, string.Join(", ", listing.Children.Select(d => d.Title)));
feed.AddRange(listing.Children);
}
}
var connections = _stateService.GetAll();
foreach (var c in connections)
{
if (_feedService.TryGetFeed(c.FeedId, out var existingFeed))
{
var data = existingFeed.GetData(c.LastEntryName);
if (data.Count() > 0)
{
_logger.LogInformation("Streaming new data: {0}",
string.Join(", ", data.Select(d => d.Title)));
_ = c.StreamChannel.Writer.WriteAsync(data, stoppingToken);
c.LastEntryName = existingFeed.LastEntryName;
}
}
}
}
catch (Exception ex)
{
Debug.Write(ex.Message);
}
await Task.Delay(1000, stoppingToken);
}while (!stoppingToken.IsCancellationRequested);
}