/// <summary>
/// Returns a Tcp Connection back to cache for reuse by other requests
/// </summary>
/// <param name="connection"></param>
/// <returns></returns>
internal async Task ReleaseClient(TcpConnectionCache connection)
{
connection.LastAccess = DateTime.Now;
var key = GetConnectionKey(connection.HostName, connection.port, connection.IsHttps, connection.Version);
await connectionAccessLock.WaitAsync();
try
{
List <TcpConnectionCache> cachedConnections;
connectionCache.TryGetValue(key, out cachedConnections);
if (cachedConnections != null)
{
cachedConnections.Add(connection);
}
else
{
connectionCache.Add(key, new List <TcpConnectionCache>()
{
connection
});
}
}
finally { connectionAccessLock.Release(); }
}
/// <summary>
/// Get a TcpConnection to the specified host, port optionally HTTPS and a particular HTTP version
/// </summary>
/// <param name="hostname"></param>
/// <param name="port"></param>
/// <param name="isHttps"></param>
/// <param name="version"></param>
/// <returns></returns>
internal async Task <TcpConnectionCache> GetClient(string hostname, int port, bool isHttps, Version version,
ExternalProxy upStreamHttpProxy, ExternalProxy upStreamHttpsProxy, int bufferSize, SslProtocols supportedSslProtocols,
RemoteCertificateValidationCallback remoteCertificateValidationCallBack, LocalCertificateSelectionCallback localCertificateSelectionCallback)
{
List <TcpConnectionCache> cachedConnections = null;
TcpConnectionCache cached = null;
//Get a unique string to identify this connection
var key = GetConnectionKey(hostname, port, isHttps, version);
while (true)
{
await connectionAccessLock.WaitAsync();
try
{
connectionCache.TryGetValue(key, out cachedConnections);
if (cachedConnections != null && cachedConnections.Count > 0)
{
cached = cachedConnections.First();
cachedConnections.Remove(cached);
}
else
{
cached = null;
}
}
finally { connectionAccessLock.Release(); }
if (cached != null && !cached.TcpClient.Client.IsConnected())
{
cached.TcpClient.Client.Dispose();
cached.TcpClient.Close();
continue;
}
if (cached == null)
{
break;
}
}
if (cached == null)
{
cached = await CreateClient(hostname, port, isHttps, version, upStreamHttpProxy, upStreamHttpsProxy, bufferSize, supportedSslProtocols,
remoteCertificateValidationCallBack, localCertificateSelectionCallback);
}
if (cachedConnections == null || cachedConnections.Count() <= 2)
{
var task = CreateClient(hostname, port, isHttps, version, upStreamHttpProxy, upStreamHttpsProxy, bufferSize, supportedSslProtocols,
remoteCertificateValidationCallBack, localCertificateSelectionCallback)
.ContinueWith(async(x) => { if (x.Status == TaskStatus.RanToCompletion)
{
await ReleaseClient(x.Result);
}
});
}
return(cached);
}