/*
    * 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.giraph.utils;
  
  import org.apache.log4j.Logger;
  
  import com.yourkit.api.Controller;
  import com.yourkit.api.ProfilingModes;
  
  /**
   * Helper for YourKit profiling from within the code.
   *
   * See the following for information about usage:
   *  - http://www.yourkit.com/docs/95/help/api.jsp
   *  - http://www.yourkit.com/docs/95/api/index.html
   *
   * This class is a simple helper around the API mentioned above
   * followed by any amount of snapshotX calls and finally
   * {@link YourKitContext#stop()}.
   * See also {@link YourKitContext}.
   *
   * As of 05/2013 YourKit is not publishing their API jars to Maven, but their
   * license allows us to do it, so we have setup a repository to do this.
   * See https://github.com/facebook/sonatype-yourkit for more info.
   */
  public class YourKitProfiler {
    /** Logger */
    private static final Logger LOG = Logger.getLogger(YourKitProfiler.class);
    /** Record every ALLOCATION_RECORDING_INTERVAL'th allocation */
    private static final int ALLOCATION_RECORDING_INTERVAL = 1000;
  
    /** Don't construct, allow inheritance */
    protected YourKitProfiler() { }
  
    /**
     * Create a YourKit controller and do some or all of
     * {@link Controller#enableExceptionTelemetry()}
     * {@link Controller#startCPUProfiling(long, String, String)}
     * {@link Controller#startAllocationRecording(boolean, int, boolean,
     * int, boolean, boolean)}
     * based on boolean config options passed as method parameters
     *
     * @param enableStackTelemetry      enable stack telementry
     * @param enableCPUProfilling       enable CPU profilling
     * @param enableAllocationRecording enable allocation recording
     *
     * @return profiler context, or null if controller cannot be created
     */
    public static YourKitContext startProfile(boolean enableStackTelemetry,
                                              boolean enableCPUProfilling,
                                              boolean enableAllocationRecording) {
      Controller controller;
      try {
        controller = new Controller();
        // CHECKSTYLE: stop IllegalCatch
      } catch (Exception e) {
        // CHECKSTYLE: resume IllegalCatch
        LOG.info("Failed to set up YourKit controller", e);
        return null;
      }
  
      try {
        if (enableStackTelemetry) {
          controller.enableStackTelemetry();
          LOG.info("Enabled Yourkit stack telemetry");
        }
        // CHECKSTYLE: stop IllegalCatch
      } catch (Exception e) {
        // CHECKSTYLE: resume IllegalCatch
        LOG.info("Failed to enable YourKit stack telemetry", e);
      }
  
      try {
        if (enableCPUProfilling) {
          controller.startCPUProfiling(ProfilingModes.CPU_SAMPLING,
            Controller.DEFAULT_FILTERS, Controller.DEFAULT_WALLTIME_SPEC);
          LOG.info("Started YourKit CPU profiling");
        }
        // CHECKSTYLE: stop IllegalCatch
      } catch (Exception e) {
        // CHECKSTYLE: resume IllegalCatch
        LOG.info("Failed to start YourKit CPU profiling", e);
      }
 
     try {
       if (enableAllocationRecording) {
         controller.startAllocationRecording(true, ALLOCATION_RECORDING_INTERVAL,
             false, -1, true, false);
         LOG.info("Started YourKit allocation recording");
       }
       // CHECKSTYLE: stop IllegalCatch
     } catch (Exception e) {
       // CHECKSTYLE: resume IllegalCatch
       LOG.info("Failed to start YourKit allocation recording", e);
     }
 
     return new YourKitContext(controller);
   }
 }