io.grpc.internal.ApplicationThreadDeframerListener Maven / Gradle / Ivy
/*
* Copyright 2019 The gRPC Authors
*
* 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.internal;
import static com.google.common.base.Preconditions.checkNotNull;
import java.io.InputStream;
import java.util.ArrayDeque;
import java.util.Queue;
/**
* Listener for when deframing on the application thread, which calls the real listener on the
* transport thread. May only be called on the application thread.
*
* Does not call the delegate's {@code messagesAvailable()}. It's expected that
* {@code messageReadQueuePoll()} is called on the application thread from within a message producer
* managed elsewhere.
*/
final class ApplicationThreadDeframerListener implements MessageDeframer.Listener {
public interface TransportExecutor {
void runOnTransportThread(Runnable r);
}
private final TransportExecutor transportExecutor;
private final MessageDeframer.Listener storedListener;
/** Queue for messages returned by the deframer when deframing in the application thread. */
private final Queue messageReadQueue = new ArrayDeque<>();
public ApplicationThreadDeframerListener(
MessageDeframer.Listener listener, TransportExecutor transportExecutor) {
this.storedListener = checkNotNull(listener, "listener");
this.transportExecutor = checkNotNull(transportExecutor, "transportExecutor");
}
@Override
public void bytesRead(final int numBytes) {
transportExecutor.runOnTransportThread(
new Runnable() {
@Override
public void run() {
storedListener.bytesRead(numBytes);
}
});
}
@Override
public void messagesAvailable(StreamListener.MessageProducer producer) {
InputStream message;
while ((message = producer.next()) != null) {
messageReadQueue.add(message);
}
}
@Override
public void deframerClosed(final boolean hasPartialMessage) {
transportExecutor.runOnTransportThread(
new Runnable() {
@Override
public void run() {
storedListener.deframerClosed(hasPartialMessage);
}
});
}
@Override
public void deframeFailed(final Throwable cause) {
transportExecutor.runOnTransportThread(
new Runnable() {
@Override
public void run() {
storedListener.deframeFailed(cause);
}
});
}
public InputStream messageReadQueuePoll() {
return messageReadQueue.poll();
}
}