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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.utils;
  
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.Set;
  
  public class AtlasPerfMetrics {
      private final Map<String, Metric> metrics     = new LinkedHashMap<>();
      private       long                startTimeMs = -1;
  
      public MetricRecorder getMetricRecorder(String name) {
          return new MetricRecorder(name);
      }
  
      public void recordMetric(MetricRecorder recorder) {
          if (recorder != null) {
              final String name      = recorder.name;
              final long   timeTaken = recorder.getElapsedTime();
  
              if (startTimeMs == -1) {
                  startTimeMs = System.currentTimeMillis();
              }
  
              Metric metric = metrics.computeIfAbsent(name, Metric::new);
  
              metric.invocations++;
              metric.totalTimeMSecs += timeTaken;
          }
      }
  
      public void clear() {
          metrics.clear();
  
          startTimeMs = -1;
      }
  
      public boolean isEmpty() {
          return metrics.isEmpty();
      }
  
      public Set<String> getMetricsNames() {
          return metrics.keySet();
      }
  
      public Metric getMetric(String name) {
          return metrics.get(name);
      }
  
      @Override
      public String toString() {
          StringBuilder sb = new StringBuilder();
  
          sb.append("{");
  
          if (!metrics.isEmpty()) {
              for (Metric metric : metrics.values()) {
                  sb.append("\"").append(metric.getName()).append("\":{\"count\":").append(metric.getInvocations()).append(",\"timeTaken\":").append(metric.getTotalTimeMSecs()).append("},");
              }
  
              sb.append("\"totalTime\":").append(System.currentTimeMillis() - startTimeMs);
          }
  
          sb.append("}");
  
          return sb.toString();
      }
  
      public static class Metric {
          private final String name;
          private       short  invocations;
          private       long   totalTimeMSecs;
  
          public Metric(String name) {
              this.name = name;
          }
  
          public String getName() {
              return name;
          }
  
          public short getInvocations() {
              return invocations;
          }
  
          public long getTotalTimeMSecs() {
              return totalTimeMSecs;
          }
      }
  
      public static class MetricRecorder {
          private final String name;
          private final long   startTimeMs = System.currentTimeMillis();
  
          MetricRecorder(String name) {
              this.name = name;
          }
  
          long getElapsedTime() {
              return System.currentTimeMillis() - startTimeMs;
          }
      }
  }
  