RemoteInterpreterEventPoller.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.zeppelin.interpreter.remote;

import com.google.gson.Gson;
import org.apache.thrift.TException;
import org.apache.zeppelin.display.AngularObject;
import org.apache.zeppelin.display.AngularObjectRegistry;
import org.apache.zeppelin.interpreter.InterpreterContextRunner;
import org.apache.zeppelin.interpreter.InterpreterGroup;
import org.apache.zeppelin.interpreter.thrift.RemoteInterpreterEvent;
import org.apache.zeppelin.interpreter.thrift.RemoteInterpreterEventType;
import org.apache.zeppelin.interpreter.thrift.RemoteInterpreterService.Client;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 */
public class RemoteInterpreterEventPoller extends Thread {
  private static final Logger logger = LoggerFactory.getLogger(RemoteInterpreterEventPoller.class);

  private volatile boolean shutdown;

  private RemoteInterpreterProcess interpreterProcess;
  private InterpreterGroup interpreterGroup;

  public RemoteInterpreterEventPoller() {
    shutdown = false;
  }

  public void setInterpreterProcess(RemoteInterpreterProcess interpreterProcess) {
    this.interpreterProcess = interpreterProcess;
  }

  public void setInterpreterGroup(InterpreterGroup interpreterGroup) {
    this.interpreterGroup = interpreterGroup;
  }

  @Override
  public void run() {
    Client client = null;

    while (!shutdown && interpreterProcess.isRunning()) {
      try {
        client = interpreterProcess.getClient();
      } catch (Exception e1) {
        logger.error("Can't get RemoteInterpreterEvent", e1);
        waitQuietly();
        continue;
      }

      RemoteInterpreterEvent event = null;
      boolean broken = false;
      try {
        event = client.getEvent();
      } catch (TException e) {
        broken = true;
        logger.error("Can't get RemoteInterpreterEvent", e);
        waitQuietly();
        continue;
      } finally {
        interpreterProcess.releaseClient(client, broken);
      }

      Gson gson = new Gson();

      AngularObjectRegistry angularObjectRegistry = interpreterGroup.getAngularObjectRegistry();

      try {
        if (event.getType() == RemoteInterpreterEventType.NO_OP) {
          continue;
        } else if (event.getType() == RemoteInterpreterEventType.ANGULAR_OBJECT_ADD) {
          AngularObject angularObject = gson.fromJson(event.getData(), AngularObject.class);
          angularObjectRegistry.add(angularObject.getName(),
              angularObject.get(), angularObject.getNoteId());
        } else if (event.getType() == RemoteInterpreterEventType.ANGULAR_OBJECT_UPDATE) {
          AngularObject angularObject = gson.fromJson(event.getData(),
              AngularObject.class);
          AngularObject localAngularObject = angularObjectRegistry.get(
              angularObject.getName(), angularObject.getNoteId());
          if (localAngularObject instanceof RemoteAngularObject) {
            // to avoid ping-pong loop
            ((RemoteAngularObject) localAngularObject).set(
                angularObject.get(), true, false);
          } else {
            localAngularObject.set(angularObject.get());
          }
        } else if (event.getType() == RemoteInterpreterEventType.ANGULAR_OBJECT_REMOVE) {
          AngularObject angularObject = gson.fromJson(event.getData(), AngularObject.class);
          angularObjectRegistry.remove(angularObject.getName(), angularObject.getNoteId());
        } else if (event.getType() == RemoteInterpreterEventType.RUN_INTERPRETER_CONTEXT_RUNNER) {
          InterpreterContextRunner runnerFromRemote = gson.fromJson(
              event.getData(), RemoteInterpreterContextRunner.class);

          interpreterProcess.getInterpreterContextRunnerPool().run(
              runnerFromRemote.getNoteId(), runnerFromRemote.getParagraphId());
        }
        logger.debug("Event from remoteproceess {}", event.getType());
      } catch (Exception e) {
        logger.error("Can't handle event " + event, e);
      }
    }
  }

  private void waitQuietly() {
    try {
      synchronized (this) {
        wait(1000);
      }
    } catch (InterruptedException ignored) {
    }
  }

  public void shutdown() {
    shutdown = true;
    synchronized (this) {
      notify();
    }
  }
}