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;
  
  /**
   * The position of an entry, identified by log segment sequence number and entry id.
   */
  class EntryPosition {
  
      private long lssn;
      private long entryId;
  
      EntryPosition(long lssn, long entryId) {
          this.lssn = lssn;
          this.entryId = entryId;
      }
  
      public synchronized long getLogSegmentSequenceNumber() {
          return lssn;
      }
  
      public synchronized long getEntryId() {
          return entryId;
      }
  
      public synchronized boolean advance(long lssn, long entryId) {
          if (lssn == this.lssn) {
              if (entryId <= this.entryId) {
                  return false;
              }
              this.entryId = entryId;
              return true;
          } else if (lssn > this.lssn) {
              this.lssn = lssn;
              this.entryId = entryId;
              return true;
          } else {
              return false;
          }
      }
  
      @Override
      public String toString() {
          StringBuilder sb = new StringBuilder();
          sb.append("(").append(lssn).append(", ").append(entryId).append(")");
          return sb.toString();
      }
  }
  