io.grpc.ServerStreamTracer Maven / Gradle / Ivy
/*
* Copyright 2017, gRPC Authors All rights reserved.
*
* 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 io.grpc;
import javax.annotation.concurrent.ThreadSafe;
/**
* Listens to events on a stream to collect metrics.
*/
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/2861")
@ThreadSafe
public abstract class ServerStreamTracer extends StreamTracer {
/**
* Called before the interceptors and the call handlers and make changes to the Context object
* if needed.
*/
public Context filterContext(Context context) {
return context;
}
/**
* Called when {@link ServerCall} is created. This is for the tracer to access information about
* the {@code ServerCall}. Called after {@link #filterContext} and before the application call
* handler.
*/
public void serverCallStarted(ServerCall call) {
}
public abstract static class Factory {
/**
* Creates a {@link ServerStreamTracer} for a new server stream.
*
* Called right before the stream is created
*
* @param fullMethodName the fully qualified method name
* @param headers the received request headers. It can be safely mutated within this method.
* It should not be saved because it is not safe for read or write after the method
* returns.
*/
public abstract ServerStreamTracer newServerStreamTracer(
String fullMethodName, Metadata headers);
}
}