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.distributedlog.function;
  
  import java.util.List;
  import java.util.function.Function;
  import org.apache.distributedlog.DistributedLogConstants;
  import org.apache.distributedlog.LogSegmentMetadata;
  
  /**
   * Retrieve the last tx id from list of log segments.
   */
  public class GetLastTxIdFunction implements Function<List<LogSegmentMetadata>, Long> {
  
      public static final GetLastTxIdFunction INSTANCE = new GetLastTxIdFunction();
  
      private GetLastTxIdFunction() {}
  
      @Override
      public Long apply(List<LogSegmentMetadata> segmentList) {
          long lastTxId = DistributedLogConstants.INVALID_TXID;
          for (LogSegmentMetadata l : segmentList) {
              lastTxId = Math.max(lastTxId, l.getLastTxId());
          }
          return lastTxId;
      }
  }
  