/*
    * 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.hadoop.hbase.codec.prefixtree.decode;
  
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellComparator;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.KeyValueUtil;
  import org.apache.hadoop.hbase.SettableSequenceId;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  /**
   * As the PrefixTreeArrayScanner moves through the tree bytes, it changes the values in the fields
   * of this class so that Cell logic can be applied, but without allocating new memory for every Cell
   * iterated through.
   */
  @InterfaceAudience.Private
  public class PrefixTreeCell implements Cell, SettableSequenceId, Comparable<Cell> {
  
    /********************** static **********************/
  
    public static final KeyValue.Type[] TYPES = new KeyValue.Type[256];
    static {
      for (KeyValue.Type type : KeyValue.Type.values()) {
        TYPES[type.getCode() & 0xff] = type;
      }
    }
  
    //Same as KeyValue constructor.  Only used to avoid NPE's when full cell hasn't been initialized.
    public static final KeyValue.Type DEFAULT_TYPE = KeyValue.Type.Put;
  
    /******************** fields ************************/
  
    protected byte[] block;
    //we could also avoid setting the mvccVersion in the scanner/searcher, but this is simpler
    protected boolean includeMvccVersion;
  
    protected byte[] rowBuffer;
    protected int rowLength;
  
    protected byte[] familyBuffer;
    protected int familyOffset;
    protected int familyLength;
  
    protected byte[] qualifierBuffer;// aligned to the end of the array
    protected int qualifierOffset;
    protected int qualifierLength;
  
    protected Long timestamp;
    protected Long mvccVersion;
  
    protected KeyValue.Type type;
  
    protected int absoluteValueOffset;
    protected int valueLength;
  
    protected byte[] tagsBuffer;
    protected int tagsOffset;
    protected int tagsLength;
  
    /********************** Cell methods ******************/
  
    /**
     * For debugging.  Currently creates new KeyValue to utilize its toString() method.
     */
    @Override
    public String toString() {
      return getKeyValueString();
    }
  
    @Override
    public boolean equals(Object obj) {
      if (!(obj instanceof Cell)) {
        return false;
      }
      //Temporary hack to maintain backwards compatibility with KeyValue.equals
      return CellComparator.equalsIgnoreMvccVersion(this, (Cell)obj);
  
      //TODO return CellComparator.equals(this, (Cell)obj);//see HBASE-6907
    }
  
    @Override
   public int hashCode() {
     return CellComparator.hashCodeIgnoreMvcc(this);
   }
 
   @Override
   public int compareTo(Cell other) {
     return CellComparator.compare(this, other, false);
   }
 
   @Override
   public long getTimestamp() {
     return timestamp;
   }
 
   @Override
   public long getMvccVersion() {
     if (!includeMvccVersion) {
       return 0L;
     }
     return mvccVersion;
   }
 
   @Override
   public long getSequenceId() {
     return getMvccVersion();
   }
 
   @Override
   public int getValueLength() {
     return valueLength;
   }
 
   @Override
   public byte[] getRowArray() {
     return rowBuffer;
   }
 
   @Override
   public int getRowOffset() {
     return 0;
   }
 
   @Override
   public short getRowLength() {
     return (short) rowLength;
   }
 
   @Override
   public byte[] getFamilyArray() {
     return familyBuffer;
   }
 
   @Override
   public int getFamilyOffset() {
     return familyOffset;
   }
 
   @Override
   public byte getFamilyLength() {
     return (byte) familyLength;
   }
 
   @Override
   public byte[] getQualifierArray() {
     return qualifierBuffer;
   }
 
   @Override
   public int getQualifierOffset() {
     return qualifierOffset;
   }
 
   @Override
   public int getQualifierLength() {
     return qualifierLength;
   }
 
   @Override
   public byte[] getValueArray() {
     return block;
   }
 
   @Override
   public int getValueOffset() {
     return absoluteValueOffset;
   }
 
   @Override
   public byte getTypeByte() {
     return type.getCode();
   }
 
   /* Deprecated methods pushed into the Cell interface */
   @Override
   public byte[] getValue() {
     return CellUtil.cloneValue(this);
   }
 
   @Override
   public byte[] getFamily() {
     return CellUtil.cloneFamily(this);
   }
 
   @Override
   public byte[] getQualifier() {
     return CellUtil.cloneQualifier(this);
   }
 
   @Override
   public byte[] getRow() {
     return CellUtil.cloneRow(this);
   }
 
   /************************* helper methods *************************/
 
   /**
    * Need this separate method so we can call it from subclasses' toString() methods
    */
   protected String getKeyValueString(){
     KeyValue kv = KeyValueUtil.copyToNewKeyValue(this);
     return kv.toString();
   }
 
   @Override
   public int getTagsOffset() {
     return tagsOffset;
   }
 
   @Override
   public int getTagsLength() {
     return tagsLength;
   }
 
   @Override
   public byte[] getTagsArray() {
     return this.tagsBuffer;
   }
 
   @Override
   public void setSequenceId(long seqId) {
     mvccVersion = seqId;
   }
 }