/// <summary>
/// This Service returns the Servers known to a Server or Discovery Server.
/// </summary>
/// <param name="request">a request.</param>
/// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
/// <seealso href="https://reference.opcfoundation.org/v104/Core/docs/Part4/5.4.2/">OPC UA specification Part 4: Services, 5.4.2</seealso>
public static async Task <FindServersResponse> FindServersAsync(FindServersRequest request, ILoggerFactory?loggerFactory = null, UaApplicationOptions?options = null)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
var client = new UaTcpDiscoveryService(
new EndpointDescription
{
EndpointUrl = request.EndpointUrl,
SecurityMode = MessageSecurityMode.None,
SecurityPolicyUri = SecurityPolicyUris.None
},
loggerFactory,
options);
try
{
await client.OpenAsync().ConfigureAwait(false);
var response = await client.innerChannel.RequestAsync(request).ConfigureAwait(false);
await client.CloseAsync().ConfigureAwait(false);
return((FindServersResponse)response);
}
catch (Exception)
{
await client.AbortAsync().ConfigureAwait(false);
throw;
}
}
// The overriden For methods below create Log entries specific to all OPC UA
// service request types.
public static LogEntry For(FindServersRequest request)
{
LogEntry entry = new LogEntry("FindServersRequest");
entry.Add("RequestHeader", For(request.RequestHeader));
entry.Add("LocaleIds", For(request.LocaleIds));
entry.Add("ServerURIs", For(request.ServerUris));
return(entry);
}
public async Task <FindServersResponse> FindServersAsync(FindServersRequest findServersRequest)
{
UpdateRequestHeader(findServersRequest, true, "FindServers");
FindServersResponse findServersResponse = null;
try
{
if (UseTransportChannel)
{
var serviceResponse = await Task <IServiceResponse> .Factory.FromAsync(TransportChannel.BeginSendRequest, TransportChannel.EndSendRequest, findServersRequest, null).ConfigureAwait(false);
if (serviceResponse == null)
{
throw new ServiceResultException(StatusCodes.BadUnknownResponse);
}
ValidateResponse(serviceResponse.ResponseHeader);
findServersResponse = (FindServersResponse)serviceResponse;
}
else
{
var findServersResponseMessage = await Task <FindServersResponseMessage> .Factory.FromAsync(InnerChannel.BeginFindServers, InnerChannel.EndFindServers, new FindServersMessage(findServersRequest), null).ConfigureAwait(false);
if (findServersResponseMessage == null || findServersResponseMessage.FindServersResponse == null)
{
throw new ServiceResultException(StatusCodes.BadUnknownResponse);
}
findServersResponse = findServersResponseMessage.FindServersResponse;
ValidateResponse(findServersResponse.ResponseHeader);
}
}
finally
{
RequestCompleted(findServersRequest, findServersResponse, "FindServers");
}
return(findServersResponse);
}
/// <summary>
/// Begins an asynchronous invocation of the FindServers service.
/// </summary>
public IAsyncResult BeginFindServers(
RequestHeader requestHeader,
string endpointUrl,
StringCollection localeIds,
StringCollection serverUris,
AsyncCallback callback,
object asyncState)
{
FindServersRequest request = new FindServersRequest();
request.RequestHeader = requestHeader;
request.EndpointUrl = endpointUrl;
request.LocaleIds = localeIds;
request.ServerUris = serverUris;
UpdateRequestHeader(request, requestHeader == null, "FindServers");
if (UseTransportChannel)
{
return TransportChannel.BeginSendRequest(request, callback, asyncState);
}
return InnerChannel.BeginFindServers(new FindServersMessage(request), callback, asyncState);
}
/// <summary>
/// Invokes the FindServers service.
/// </summary>
public virtual ResponseHeader FindServers(
RequestHeader requestHeader,
string endpointUrl,
StringCollection localeIds,
StringCollection serverUris,
out ApplicationDescriptionCollection servers)
{
FindServersRequest request = new FindServersRequest();
FindServersResponse response = null;
request.RequestHeader = requestHeader;
request.EndpointUrl = endpointUrl;
request.LocaleIds = localeIds;
request.ServerUris = serverUris;
UpdateRequestHeader(request, requestHeader == null, "FindServers");
try
{
if (UseTransportChannel)
{
IServiceResponse genericResponse = TransportChannel.SendRequest(request);
if (genericResponse == null)
{
throw new ServiceResultException(StatusCodes.BadUnknownResponse);
}
ValidateResponse(genericResponse.ResponseHeader);
response = (FindServersResponse)genericResponse;
}
else
{
FindServersResponseMessage responseMessage = InnerChannel.FindServers(new FindServersMessage(request));
if (responseMessage == null || responseMessage.FindServersResponse == null)
{
throw new ServiceResultException(StatusCodes.BadUnknownResponse);
}
response = responseMessage.FindServersResponse;
ValidateResponse(response.ResponseHeader);
}
servers = response.Servers;
}
finally
{
RequestCompleted(request, response, "FindServers");
}
return response.ResponseHeader;
}
/// <summary>
/// Initializes the message with the body.
/// </summary>
public FindServersMessage(FindServersRequest FindServersRequest)
{
this.FindServersRequest = FindServersRequest;
}
