internal object DiscoverChannel(DiscoveredEndpointModel model, IChannelBuilderScope scope)
{
var discovered = PerformEndpointSearch(scope.Contract, model);
if (discovered == null || discovered.Endpoints.Count == 0)
{
throw new EndpointNotFoundException(string.Format(
"Unable to discover the endpoint for contract {0}. " +
"Either no service exists or it does not support discovery.",
scope.Contract.FullName));
}
var binding = model.Binding;
var endpointMetadata = discovered.Endpoints[0];
if (discovered.Endpoints.Count > 1 && model.EndpointPreference != null)
{
endpointMetadata = model.EndpointPreference(discovered.Endpoints);
if (endpointMetadata == null)
{
throw new EndpointNotFoundException(string.Format(
"More than one endpoint was discovered for contract {0}. " +
"However, an endpoint was not selected. This is most likely " +
"a bug with the user-defined endpoint preference.",
scope.Contract.FullName));
}
}
if (binding == null && model.DeriveBinding == false)
{
binding = GetBindingFromMetadata(endpointMetadata);
}
var address = endpointMetadata.Address;
if (model.Identity != null)
{
address = new EndpointAddress(address.Uri, model.Identity, address.Headers);
}
binding = GetEffectiveBinding(binding, address.Uri);
var channel = scope.GetChannel(scope.Contract, binding, address)();
if (channel is IContextChannel)
{
var metadata = new DiscoveredEndpointMetadata(endpointMetadata);
((IContextChannel)channel).Extensions.Add(metadata);
}
return channel;
}
private FindResponse PerformEndpointSearch(Type contract, DiscoveredEndpointModel model)
{
var criteria = CreateSearchCriteria(contract, model);
for (int i = 0; i < 2; ++i)
{
var discoveryEndpoint = GetDiscoveryEndpoint(model);
WcfBindingUtils.ConfigureQuotas(discoveryEndpoint.Binding, int.MaxValue);
var discoveryClient = new DiscoveryClient(discoveryEndpoint);
try
{
return discoveryClient.Find(criteria);
}
catch
{
// ignore failures
}
finally
{
try
{
discoveryClient.Close();
}
catch
{
// Discovery client often fails on close
}
}
// Possible stale discovery proxy...
if (i == 0)
{
var discoveryEndpointFaulted = DiscoveryEndpointFaulted;
if (discoveryEndpointFaulted != null)
{
discoveryEndpointFaulted(this, new DiscoveryEndpointFaultEventArgs(discoveryEndpoint));
}
}
}
return null;
}
void IWcfEndpointVisitor.VisitBindingDiscoveredEndpoint(DiscoveredEndpointModel model)
{
throw new InvalidOperationException("Discovered endpoints can only by applied for clients.");
}
private FindCriteria CreateSearchCriteria(DiscoveredEndpointModel model)
{
var searchContract = model.SearchContract ?? contract;
var criteria = new FindCriteria(searchContract) { MaxResults = model.MaxResults };
if (model.Duration.HasValue)
{
criteria.Duration = model.Duration.Value;
}
var discovery = model.Extensions.OfType<WcfInstanceExtension>()
.Select(extension => extension.Instance)
.OfType<EndpointDiscoveryBehavior>()
.FirstOrDefault();
if (discovery != null)
{
criteria.Scopes.AddAll(discovery.Scopes);
if (model.ScopeMatchBy != null)
{
criteria.ScopeMatchBy = model.ScopeMatchBy;
}
criteria.Extensions.AddAll(discovery.Extensions);
}
return criteria;
}
private void DiscoverEndpoint(DiscoveryEndpoint discoveryEndpoint, DiscoveredEndpointModel model)
{
using (var discover = new DiscoveryClient(discoveryEndpoint))
{
var criteria = CreateSearchCriteria(model);
var discovered = discover.Find(criteria);
if (discovered.Endpoints.Count > 0)
{
var binding = model.Binding;
var endpointMetadata = discovered.Endpoints[0];
if (discovered.Endpoints.Count > 1 && model.EndpointPreference != null)
{
endpointMetadata = model.EndpointPreference(discovered.Endpoints);
if (endpointMetadata == null)
{
throw new EndpointNotFoundException(string.Format(
"More than one endpoint was discovered for contract {0}. " +
"However, an endpoint could be selected. This is most likely " +
"a bug with the user-defined endpoint prefeence.",
contract.FullName));
}
}
if (binding == null && model.DeriveBinding == false)
{
binding = GetBindingFromMetadata(endpointMetadata);
}
var address = endpointMetadata.Address;
if (model.Identity != null)
{
address = new EndpointAddress(address.Uri, model.Identity, address.Headers);
}
binding = GetEffectiveBinding(binding, address.Uri);
var innerCreator = GetChannel(contract, binding, address);
channelCreator = () =>
{
var channel = (IChannel)innerCreator();
if (channel is IContextChannel)
{
var metadata = new DiscoveredEndpointMetadata(endpointMetadata);
((IContextChannel)channel).Extensions.Add(metadata);
}
return channel;
};
}
else
{
throw new EndpointNotFoundException(string.Format(
"Unable to discover the endpoint for contract {0}. " +
"Either no service exists or it does not support discovery.",
contract.FullName));
}
}
}
void IWcfEndpointVisitor.VisitBindingDiscoveredEndpoint(DiscoveredEndpointModel model)
{
var discoveryEndpoint = model.DiscoveryEndpoint ?? new UdpDiscoveryEndpoint();
DiscoverEndpoint(discoveryEndpoint, model);
}
private static FindCriteria CreateSearchCriteria(Type contract, DiscoveredEndpointModel model)
{
var searchContract = model.SearchContract ?? contract;
var criteria = model.SearchAnyContract ? new FindCriteria() : new FindCriteria(searchContract);
criteria.Duration = model.Duration.GetValueOrDefault(DefaultDuration);
criteria.MaxResults = model.MaxResults;
var discovery = model.Extensions.OfType<WcfInstanceExtension>()
.Select(extension => extension.Instance)
.OfType<WcfEndpointDiscoveryMetadata>()
.FirstOrDefault();
if (discovery != null)
{
criteria.Scopes.AddAll(discovery.Scopes);
if (model.ScopeMatchBy != null)
{
criteria.ScopeMatchBy = model.ScopeMatchBy;
}
criteria.Extensions.AddAll(discovery.Extensions);
}
return criteria;
}
private DiscoveryEndpoint GetDiscoveryEndpoint(DiscoveredEndpointModel model)
{
if (model.DiscoveryEndpoint != null)
{
return model.DiscoveryEndpoint;
}
var provider = model.DiscoveryEndpointProvider ?? DiscoveryEndpointProvider;
if (provider != null)
{
var discoveryEndpoint = provider.GetDiscoveryEndpoint();
if (discoveryEndpoint != null)
{
return discoveryEndpoint;
}
}
return new UdpDiscoveryEndpoint();
}
private void DiscoverEndpoint(DiscoveryEndpoint discoveryEndpoint, DiscoveredEndpointModel model)
{
using (var discover = new DiscoveryClient(discoveryEndpoint))
{
var criteria = CreateSearchCriteria(model);
var discovered = discover.Find(criteria);
if (discovered.Endpoints.Count > 0)
{
var binding = model.Binding;
var endpointMetadata = discovered.Endpoints[0];
if (binding == null && model.DeriveBinding == false)
{
binding = GetBindingFromMetadata(endpointMetadata);
}
var address = endpointMetadata.Address;
binding = GetEffectiveBinding(binding, address.Uri);
channelCreator = GetChannel(contract, binding, address);
}
else
{
throw new EndpointNotFoundException(string.Format(
"Unable to discover the endpoint address for contract {0}. " +
"Either no service exists or it does not support discovery.",
contract.FullName));
}
}
}
