seb-win-refactoring/SafeExamBrowser.Runtime/Communication/RuntimeHost.cs

95 lines
3.6 KiB
C#

/*
* Copyright (c) 2018 ETH Zürich, Educational Development and Technology (LET)
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
using System;
using SafeExamBrowser.Contracts.Communication.Data;
using SafeExamBrowser.Contracts.Communication.Events;
using SafeExamBrowser.Contracts.Communication.Hosts;
using SafeExamBrowser.Contracts.Configuration;
using SafeExamBrowser.Contracts.Logging;
using SafeExamBrowser.Core.Communication.Hosts;
namespace SafeExamBrowser.Runtime.Communication
{
internal class RuntimeHost : BaseHost, IRuntimeHost
{
private bool allowConnection = true;
private IConfigurationRepository configuration;
public Guid StartupToken { private get; set; }
public event CommunicationEventHandler ClientDisconnected;
public event CommunicationEventHandler ClientReady;
public event CommunicationEventHandler<PasswordReplyEventArgs> PasswordReceived;
public event CommunicationEventHandler<ReconfigurationEventArgs> ReconfigurationRequested;
public event CommunicationEventHandler ShutdownRequested;
public RuntimeHost(string address, IConfigurationRepository configuration, IHostObjectFactory factory, ILogger logger) : base(address, factory, logger)
{
this.configuration = configuration;
}
protected override bool OnConnect(Guid? token = null)
{
var authenticated = StartupToken == token;
var accepted = allowConnection && authenticated;
if (accepted)
{
allowConnection = false;
}
return accepted;
}
protected override void OnDisconnect()
{
ClientDisconnected?.Invoke();
// TODO: Handle client crash scenario!
// If a client crashes or hangs when terminating (which should not happen!), it could be that it never gets to disconnect from
// the RuntimeHost - in that case, allowConnection prohibits restarting a new session as long as it's only set here!
// -> Move AllowConnection to interface and reset it in SessionController?
// -> Only possible as long as just the client connects, with service and client a more elaborate solution will be needed!
// -> E.g. ClientId and ServiceId, and then AllowClientConnection and AllowServiceConnection?
allowConnection = true;
}
protected override Response OnReceive(Message message)
{
switch (message)
{
case PasswordReplyMessage r:
PasswordReceived?.InvokeAsync(new PasswordReplyEventArgs { Password = r.Password, RequestId = r.RequestId, Success = r.Success });
return new SimpleResponse(SimpleResponsePurport.Acknowledged);
case ReconfigurationMessage r:
ReconfigurationRequested?.InvokeAsync(new ReconfigurationEventArgs { ConfigurationPath = r.ConfigurationPath });
return new SimpleResponse(SimpleResponsePurport.Acknowledged);
}
return new SimpleResponse(SimpleResponsePurport.UnknownMessage);
}
protected override Response OnReceive(SimpleMessagePurport message)
{
switch (message)
{
case SimpleMessagePurport.ClientIsReady:
ClientReady?.Invoke();
return new SimpleResponse(SimpleResponsePurport.Acknowledged);
case SimpleMessagePurport.ConfigurationNeeded:
// TODO: Not the job of the host, fire event or alike!
return new ConfigurationResponse { Configuration = configuration.BuildClientConfiguration() };
case SimpleMessagePurport.RequestShutdown:
ShutdownRequested?.Invoke();
return new SimpleResponse(SimpleResponsePurport.Acknowledged);
}
return new SimpleResponse(SimpleResponsePurport.UnknownMessage);
}
}
}