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.pc;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.Set;
  
  public class StatusReporter<T, U> {
      private static final Logger LOG = LoggerFactory.getLogger(StatusReporter.class);
  
      private final Map<T, U> producedItems = new LinkedHashMap<>();
      private final Set<T>    processedSet  = new HashSet<>();
      private final long      timeoutDuration;
      private       long      lastAck;
  
      public StatusReporter() {
          this.timeoutDuration = -1;
      }
  
      public StatusReporter(long timeoutDurationInMs) {
          this.timeoutDuration = timeoutDurationInMs;
      }
  
      public void produced(T item, U index) {
          this.producedItems.put(item, index);
      }
  
      public void processed(T item) {
          this.processedSet.add(item);
      }
  
      public void processed(T[] index) {
          this.processedSet.addAll(Arrays.asList(index));
      }
  
      public U ack() {
          U ack = null;
          U ret;
  
          do {
              Map.Entry<T, U> firstElement = getFirstElement(this.producedItems);
  
              ret = completionIndex(firstElement);
  
              if (ret != null) {
                  ack = ret;
              }
          }
          while (ret != null);
  
          return ack;
      }
  
      public int getProducedCount() {
          return this.producedItems.size();
      }
  
      public int getProcessedCount() {
          return this.processedSet.size();
      }
  
      private Map.Entry<T, U> getFirstElement(Map<T, U> map) {
          if (map.isEmpty()) {
              return null;
          }
  
          return map.entrySet().iterator().next();
      }
  
      private U completionIndex(Map.Entry<T, U> lookFor) {
          U ack = null;
  
          if (lookFor == null) {
              return ack;
          }
  
          if (hasTimeoutDurationReached(System.currentTimeMillis())) {
              LOG.warn("Ack: Timeout: {} - {}", lookFor.getKey(), lookFor.getValue());
  
              return acknowledged(lookFor);
          }
  
          if (!processedSet.contains(lookFor.getKey())) {
              return ack;
          }
  
          return acknowledged(lookFor);
      }
  
      private U acknowledged(Map.Entry<T, U> lookFor) {
          U ack = lookFor.getValue();
  
          producedItems.remove(lookFor.getKey());
          processedSet.remove(lookFor.getKey());
  
          return ack;
      }
  
      private boolean hasTimeoutDurationReached(long now) {
          boolean b = (this.timeoutDuration > -1) && (this.lastAck != 0) && ((now - this.lastAck) >= timeoutDuration);
  
          lastAck = System.currentTimeMillis();
  
          return b;
      }
  }
  