public static DnsClientConnection GetConnection(NameServerAddress server, NetProxy proxy)
{
switch (server.Protocol)
{
case DnsTransportProtocol.Udp:
return(new UdpClientConnection(server, proxy));
case DnsTransportProtocol.Tcp:
{
ConcurrentDictionary <NetProxy, TcpClientConnection> existingTcpConnection = _existingTcpConnections.GetOrAdd(server, delegate(NameServerAddress nameServer)
{
return(new ConcurrentDictionary <NetProxy, TcpClientConnection>());
});
NetProxy proxyKey = proxy;
if (proxyKey == null)
{
proxyKey = NetProxy.NONE;
}
return(existingTcpConnection.GetOrAdd(proxyKey, delegate(NetProxy netProxyKey)
{
TcpClientConnection connection = new TcpClientConnection(server, proxy);
connection.Pooled = true;
return connection;
}));
}
case DnsTransportProtocol.Tls:
{
ConcurrentDictionary <NetProxy, TlsClientConnection> existingTlsConnection = _existingTlsConnections.GetOrAdd(server, delegate(NameServerAddress nameServer)
{
return(new ConcurrentDictionary <NetProxy, TlsClientConnection>());
});
NetProxy proxyKey = proxy;
if (proxyKey == null)
{
proxyKey = NetProxy.NONE;
}
return(existingTlsConnection.GetOrAdd(proxyKey, delegate(NetProxy netProxyKey)
{
TlsClientConnection connection = new TlsClientConnection(server, proxy);
connection.Pooled = true;
return connection;
}));
}
case DnsTransportProtocol.Https:
{
ConcurrentDictionary <NetProxy, HttpsClientConnection> existingHttpsConnection = _existingHttpsConnections.GetOrAdd(server, delegate(NameServerAddress nameServer)
{
return(new ConcurrentDictionary <NetProxy, HttpsClientConnection>());
});
NetProxy proxyKey = proxy;
if (proxyKey == null)
{
proxyKey = NetProxy.NONE;
}
return(existingHttpsConnection.GetOrAdd(proxyKey, delegate(NetProxy netProxyKey)
{
HttpsClientConnection connection = new HttpsClientConnection(server, proxy);
connection.Pooled = true;
return connection;
}));
}
case DnsTransportProtocol.HttpsJson:
{
ConcurrentDictionary <NetProxy, HttpsJsonClientConnection> existingHttpsJsonConnection = _existingHttpsJsonConnections.GetOrAdd(server, delegate(NameServerAddress nameServer)
{
return(new ConcurrentDictionary <NetProxy, HttpsJsonClientConnection>());
});
NetProxy proxyKey = proxy;
if (proxyKey == null)
{
proxyKey = NetProxy.NONE;
}
return(existingHttpsJsonConnection.GetOrAdd(proxyKey, delegate(NetProxy netProxyKey)
{
HttpsJsonClientConnection connection = new HttpsJsonClientConnection(server, proxy);
connection.Pooled = true;
return connection;
}));
}
default:
throw new NotSupportedException("DnsClient protocol not supported: " + server.Protocol.ToString());
}
}
static DnsClientConnection()
{
_maintenanceTimer = new Timer(delegate(object state)
{
try
{
DateTime expiryTime = DateTime.UtcNow.AddMilliseconds(CONNECTION_EXPIRY * -1);
//cleanup unused tcp connections
foreach (NameServerAddress nameServer in _existingTcpConnections.Keys.ToArray())
{
ConcurrentDictionary <object, TcpClientConnection> existingTcpConnection = _existingTcpConnections[nameServer];
foreach (object proxy in existingTcpConnection.Keys.ToArray())
{
TcpClientConnection connection = existingTcpConnection[proxy];
if (connection.LastQueried < expiryTime)
{
if (existingTcpConnection.TryRemove(proxy, out TcpClientConnection removedConnection))
{
removedConnection.Pooled = false;
removedConnection.Dispose();
}
}
}
if (existingTcpConnection.IsEmpty)
{
_existingTcpConnections.TryRemove(nameServer, out _);
}
}
//cleanup unused tls connections
foreach (NameServerAddress nameServer in _existingTlsConnections.Keys.ToArray())
{
ConcurrentDictionary <object, TlsClientConnection> existingTlsConnection = _existingTlsConnections[nameServer];
foreach (object proxy in existingTlsConnection.Keys.ToArray())
{
TlsClientConnection connection = existingTlsConnection[proxy];
if (connection.LastQueried < expiryTime)
{
if (existingTlsConnection.TryRemove(proxy, out TlsClientConnection removedConnection))
{
removedConnection.Pooled = false;
removedConnection.Dispose();
}
}
}
if (existingTlsConnection.IsEmpty)
{
_existingTlsConnections.TryRemove(nameServer, out _);
}
}
//cleanup unused https connections
foreach (NameServerAddress nameServer in _existingHttpsConnections.Keys.ToArray())
{
ConcurrentDictionary <object, HttpsClientConnection> existingHttpsConnection = _existingHttpsConnections[nameServer];
foreach (object proxy in existingHttpsConnection.Keys.ToArray())
{
HttpsClientConnection connection = existingHttpsConnection[proxy];
if (connection.LastQueried < expiryTime)
{
if (existingHttpsConnection.TryRemove(proxy, out HttpsClientConnection removedConnection))
{
removedConnection.Pooled = false;
removedConnection.Dispose();
}
}
}
if (existingHttpsConnection.IsEmpty)
{
_existingHttpsConnections.TryRemove(nameServer, out _);
}
}
//cleanup unused https json connections
foreach (NameServerAddress nameServer in _existingHttpsJsonConnections.Keys.ToArray())
{
ConcurrentDictionary <object, HttpsJsonClientConnection> existingHttpsJsonConnection = _existingHttpsJsonConnections[nameServer];
foreach (object proxy in existingHttpsJsonConnection.Keys.ToArray())
{
HttpsJsonClientConnection connection = existingHttpsJsonConnection[proxy];
if (connection.LastQueried < expiryTime)
{
if (existingHttpsJsonConnection.TryRemove(proxy, out HttpsJsonClientConnection removedConnection))
{
removedConnection.Pooled = false;
removedConnection.Dispose();
}
}
}
if (existingHttpsJsonConnection.IsEmpty)
{
_existingHttpsJsonConnections.TryRemove(nameServer, out _);
}
}
}
catch
{ }
});
_maintenanceTimer.Change(MAINTENANCE_TIMER_INITIAL_INTERVAL, MAINTENANCE_TIMER_PERIODIC_INTERVAL);
}