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.asterix.common.storage;
  
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import com.fasterxml.jackson.annotation.JsonCreator;
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  import com.fasterxml.jackson.core.JsonProcessingException;
  import com.fasterxml.jackson.databind.ObjectMapper;
  
  @JsonIgnoreProperties(ignoreUnknown = true)
  public class IndexCheckpoint {
  
      private static final Logger LOGGER = LogManager.getLogger();
      private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
      private static final long INITIAL_CHECKPOINT_ID = 0;
      // TODO(mblow): remove this marker & related logic once we no longer are able to read indexes prior to the fix
      private static final long HAS_NULL_MISSING_VALUES_FIX = -3;
      private long id;
      private long validComponentSequence;
      private long lowWatermark;
      private long lastComponentId;
      private Map<Long, Long> masterNodeFlushMap;
      private String masterNodeId;
      private long masterValidSeq;
  
      public static IndexCheckpoint first(long lastComponentSequence, long lowWatermark, long validComponentId,
              String masterNodeId) {
          IndexCheckpoint firstCheckpoint = new IndexCheckpoint();
          firstCheckpoint.id = INITIAL_CHECKPOINT_ID;
          firstCheckpoint.lowWatermark = lowWatermark;
          firstCheckpoint.validComponentSequence = lastComponentSequence;
          firstCheckpoint.lastComponentId = validComponentId;
          firstCheckpoint.masterNodeFlushMap = new HashMap<>();
          firstCheckpoint.masterNodeFlushMap.put(HAS_NULL_MISSING_VALUES_FIX, HAS_NULL_MISSING_VALUES_FIX);
          firstCheckpoint.masterNodeId = masterNodeId;
          firstCheckpoint.masterValidSeq = lastComponentSequence;
          return firstCheckpoint;
      }
  
      public static IndexCheckpoint next(IndexCheckpoint latest, long lowWatermark, long validComponentSequence,
              long lastComponentId, String masterNodeId) {
          if (lowWatermark < latest.getLowWatermark()) {
              if (LOGGER.isErrorEnabled()) {
                  LOGGER.error("low watermark {} less than the latest checkpoint low watermark {}", lowWatermark, latest);
              }
              throw new IllegalStateException("Low watermark should always be increasing");
          }
          IndexCheckpoint next = new IndexCheckpoint();
          next.id = latest.getId() + 1;
          next.lowWatermark = lowWatermark;
          next.lastComponentId = lastComponentId;
          next.validComponentSequence = validComponentSequence;
          next.masterNodeFlushMap = latest.getMasterNodeFlushMap();
          if (masterNodeId != null) {
              next.masterNodeId = masterNodeId;
              next.masterValidSeq = validComponentSequence;
          } else {
              next.masterNodeId = latest.getMasterNodeId();
              next.masterValidSeq = latest.getMasterValidSeq();
          }
          // remove any lsn from the map that wont be used anymore
          next.masterNodeFlushMap.values().removeIf(lsn -> lsn < lowWatermark && lsn != HAS_NULL_MISSING_VALUES_FIX);
          return next;
      }
  
      @JsonCreator
      private IndexCheckpoint() {
      }
  
      public long getValidComponentSequence() {
          return validComponentSequence;
      }
  
      public long getLowWatermark() {
          return lowWatermark;
      }
  
      public long getLastComponentId() {
          return lastComponentId;
      }
  
      public Map<Long, Long> getMasterNodeFlushMap() {
          return masterNodeFlushMap;
      }
  
      public long getId() {
          return id;
      }
  
      public boolean hasNullMissingValuesFix() {
          return masterNodeFlushMap.containsKey(HAS_NULL_MISSING_VALUES_FIX);
      }
  
      public String asJson() throws HyracksDataException {
          try {
              return OBJECT_MAPPER.writeValueAsString(this);
          } catch (JsonProcessingException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      public String getMasterNodeId() {
          return masterNodeId;
      }
  
      public long getMasterValidSeq() {
          return masterValidSeq;
      }
  
      public static IndexCheckpoint fromJson(String json) throws HyracksDataException {
          try {
              return OBJECT_MAPPER.readValue(json, IndexCheckpoint.class);
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      @Override
      public String toString() {
          try {
              return asJson();
          } catch (HyracksDataException e) {
              throw new IllegalStateException(e);
          }
      }
  }
  