content: /*
   * 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.beam.runners.dataflow.worker.status;
  
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import java.io.IOException;
  import java.io.InputStream;
  import java.time.Duration;
  import java.util.concurrent.ExecutionException;
  import javax.servlet.ServletOutputStream;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import org.apache.beam.runners.dataflow.worker.util.MemoryMonitor;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.io.ByteStreams;
  
  /**
   * Respond to /jfrz with a page allowing downloading of the JFR profiles.
   *
   * <p><b>Not actually serializable</b>. Its superclass is serializable but this subclass is not.
   */
  @SuppressFBWarnings("SE_BAD_FIELD") // not serializable
  public class JfrzServlet extends BaseStatusServlet {
    private static final Duration DEFAULT_RECORDING_DURATION = Duration.ofMinutes(1);
  
    private final MemoryMonitor memoryMonitor;
  
    public JfrzServlet(MemoryMonitor memoryMonitor) {
      super("jfrz");
      this.memoryMonitor = memoryMonitor;
    }
  
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
      String durationStr = req.getParameter("duration");
      Duration duration;
      if (durationStr == null) {
        duration = DEFAULT_RECORDING_DURATION;
      } else {
        duration = Duration.parse(durationStr);
      }
  
      ServletOutputStream writer = resp.getOutputStream();
  
      try (InputStream jfrStream = memoryMonitor.runJfrProfile(duration).get()) {
        resp.setContentType("application/octet-stream");
        resp.setHeader("Content-Disposition", "attachment; filename=\"profile.jfr\"");
        ByteStreams.copy(jfrStream, writer);
      } catch (ExecutionException | InterruptedException e) {
        throw new RuntimeException(e);
      }
  
      resp.setStatus(HttpServletResponse.SC_OK);
    }
  }
  