/*
* Copyright (c) 2024 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Plugins.Essentials.ServiceStack
* File: HttpServiceStack.cs
*
* HttpServiceStack.cs is part of VNLib.Plugins.Essentials.ServiceStack which is part of the larger
* VNLib collection of libraries and utilities.
*
* VNLib.Plugins.Essentials.ServiceStack is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 2 of the
* License, or (at your option) any later version.
*
* VNLib.Plugins.Essentials.ServiceStack is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see https://www.gnu.org/licenses/.
*/
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Collections.Generic;
using VNLib.Utils;
using VNLib.Net.Http;
using VNLib.Utils.Logging;
using VNLib.Plugins.Essentials.ServiceStack.Plugins;
namespace VNLib.Plugins.Essentials.ServiceStack
{
///
/// An HTTP servicing stack that manages a collection of HTTP servers
/// their service domain
///
public sealed class HttpServiceStack : VnDisposeable
{
private readonly IReadOnlyCollection _servers;
private readonly ServiceDomain _serviceDomain;
private readonly PluginManager _plugins;
private CancellationTokenSource? _cts;
private Task WaitForAllTask;
///
/// A collection of all loaded servers
///
public IEnumerable Servers => _servers;
///
/// Gets the internal that manages plugins for the entire
///
///
public IHttpPluginManager PluginManager => _plugins;
///
/// Initializes a new that will
/// generate servers to listen for services exposed by the
/// specified host context
///
internal HttpServiceStack(IReadOnlyCollection servers, ServiceDomain serviceDomain, IPluginInitializer plugins)
{
_servers = servers;
_serviceDomain = serviceDomain;
_plugins = new(plugins);
WaitForAllTask = Task.CompletedTask;
}
///
/// Starts all configured servers that observe a cancellation
/// token to cancel
///
/// The token to observe which may stop servers and cleanup the provider
public void StartServers(CancellationToken parentToken = default)
{
Check();
//Init new linked cts to stop all servers if cancelled
_cts = CancellationTokenSource.CreateLinkedTokenSource(parentToken);
//Start all servers
Task[] runners = _servers.Select(s => s.Start(_cts.Token)).ToArray();
//Check for failed startups
Task? firstFault = runners.Where(static t => t.IsFaulted).FirstOrDefault();
//Raise first exception
firstFault?.GetAwaiter().GetResult();
//Task that waits for all to exit then cleans up
WaitForAllTask = Task.WhenAll(runners)
.ContinueWith(OnAllServerExit, CancellationToken.None, TaskContinuationOptions.RunContinuationsAsynchronously, TaskScheduler.Default);
}
///
/// Loads all plugins into the service stack
///
/// A log provider for writing loading logs to
public void LoadPlugins(ILogProvider logProvider) => _plugins.LoadPlugins(logProvider);
///
/// Stops listening on all configured servers and returns a task that completes
/// when the service host has stopped all servers and unloaded resources
///
/// The task that completes when
public Task StopAndWaitAsync()
{
Check();
_cts?.Cancel();
return WaitForAllTask;
}
private void OnAllServerExit(Task allExit)
{
//Unload plugins
_plugins.UnloadPlugins();
//Unload the hosts
_serviceDomain.TearDown();
}
///
protected override void Free()
{
_cts?.Dispose();
_plugins.Dispose();
}
}
}