/*
Copyright (c) 2012 LinkedIn Corp.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package com.linkedin.d2.balancer.clients;
import com.linkedin.common.callback.Callback;
import com.linkedin.common.util.None;
import com.linkedin.d2.balancer.D2Client;
import com.linkedin.d2.balancer.Facilities;
import com.linkedin.d2.balancer.LoadBalancer;
import com.linkedin.d2.balancer.ServiceUnavailableException;
import com.linkedin.d2.balancer.properties.ServiceProperties;
import com.linkedin.d2.balancer.util.LoadBalancerUtil;
import com.linkedin.d2.discovery.event.PropertyEventThread.PropertyEventShutdownCallback;
import com.linkedin.r2.message.RequestContext;
import com.linkedin.r2.message.rest.RestRequest;
import com.linkedin.r2.message.rest.RestResponse;
import com.linkedin.r2.message.rpc.RpcRequest;
import com.linkedin.r2.message.rpc.RpcResponse;
import com.linkedin.r2.transport.common.AbstractClient;
import com.linkedin.r2.transport.common.bridge.client.TransportClient;
import com.linkedin.r2.transport.common.bridge.client.TransportClientAdapter;
import java.net.URI;
import java.util.Collections;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static com.linkedin.d2.discovery.util.LogUtil.debug;
import static com.linkedin.d2.discovery.util.LogUtil.error;
import static com.linkedin.d2.discovery.util.LogUtil.info;
import static com.linkedin.d2.discovery.util.LogUtil.trace;
import static com.linkedin.d2.discovery.util.LogUtil.warn;
public class DynamicClient extends AbstractClient implements D2Client
{
private static final Logger _log = LoggerFactory.getLogger(DynamicClient.class);
private final LoadBalancer _balancer;
private final Facilities _facilities;
public DynamicClient(LoadBalancer balancer, Facilities facilities)
{
_balancer = balancer;
_facilities = facilities;
debug(_log, "created dynamic client: ", this);
}
@Override
public void restRequest(RestRequest request,
RequestContext requestContext,
final Callback<RestResponse> callback)
{
Callback<RestResponse> transportCallback;
if (_log.isTraceEnabled())
{
trace(_log, "rest request: ", request);
transportCallback = new Callback<RestResponse>()
{
@Override
public void onError(Throwable e)
{
callback.onError(e);
trace(_log, "rest response error: ", e);
}
@Override
public void onSuccess(RestResponse result)
{
callback.onSuccess(result);
trace(_log, "rest response success: ", result);
}
};
}
else
{
transportCallback = callback;
}
try
{
TransportClient client = _balancer.getClient(request, requestContext);
if (client != null)
{
new TransportClientAdapter(client).restRequest(request, requestContext, transportCallback);
}
else
{
throw new ServiceUnavailableException("unknown: " + request.getURI(),
"got null client from load balancer");
}
}
catch (ServiceUnavailableException e)
{
callback.onError(e);
warn(_log, "unable to find service for: ", extractLogInfo(request));
}
}
@Override
@Deprecated
@SuppressWarnings("deprecation")
public void rpcRequest(RpcRequest request,
RequestContext requestContext,
Callback<RpcResponse> callback)
{
trace(_log, "rpc request: ", request);
try
{
TransportClient client = _balancer.getClient(request, requestContext);
if (client != null)
{
new TransportClientAdapter(client).rpcRequest(request, requestContext, callback);
}
else
{
throw new ServiceUnavailableException("unknown: " + request.getURI(),
"got null client from load balancer");
}
}
catch (ServiceUnavailableException e)
{
callback.onError(e);
warn(_log, "unable to find service for: ", request);
}
}
@Override
public void start(Callback<None> callback)
{
_log.info("starting D2 client");
_balancer.start(callback);
}
@Override
public void shutdown(final Callback<None> callback)
{
info(_log, "shutting down dynamic client");
_balancer.shutdown(new PropertyEventShutdownCallback()
{
@Override
public void done()
{
info(_log, "dynamic client shutdown complete");
callback.onSuccess(None.none());
}
});
}
@Override
public Facilities getFacilities()
{
return _facilities;
}
@Override
public Map<String, Object> getMetadata(URI uri)
{
if (_balancer != null)
{
try
{
String serviceName = LoadBalancerUtil.getServiceNameFromUri(uri);
ServiceProperties serviceProperties = _balancer.getLoadBalancedServiceProperties(serviceName);
if (serviceProperties != null)
{
return Collections.unmodifiableMap(serviceProperties.getServiceMetadataProperties());
}
}
catch (ServiceUnavailableException e)
{
error(_log, e);
}
}
return Collections.emptyMap();
}
private static String extractLogInfo(RestRequest request)
{
return "Rest Request: [" +
"Service: " + LoadBalancerUtil.getServiceNameFromUri(request.getURI()) + ", " +
"Method: " + request.getMethod() +
"]";
}
}