/*
    * 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.client;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.util.Bytes;
  
  /**
   * Performs multiple mutations atomically on a single row.
   * Currently {@link Put} and {@link Delete} are supported.
   *
   * The mutations are performed in the order in which they
   * were added.
   * 
   * <p>We compare and equate mutations based off their row so be careful putting RowMutations
   * into Sets or using them as keys in Maps.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Evolving
  public class RowMutations implements Row {
    private final List<Mutation> mutations = new ArrayList<Mutation>();
    private byte [] row;
  
    /** Constructor for Writable. DO NOT USE */
    public RowMutations() {}
  
    /**
     * Create an atomic mutation for the specified row.
     * @param row row key
     */
    public RowMutations(byte [] row) {
      Mutation.checkRow(row);
      this.row = Bytes.copy(row);
    }
  
    /**
     * Add a {@link Put} operation to the list of mutations
     * @param p The {@link Put} to add
     * @throws IOException
     */
    public void add(Put p) throws IOException {
      internalAdd(p);
    }
  
    /**
     * Add a {@link Delete} operation to the list of mutations
     * @param d The {@link Delete} to add
     * @throws IOException
     */
    public void add(Delete d) throws IOException {
      internalAdd(d);
    }
  
    private void internalAdd(Mutation m) throws IOException {
      int res = Bytes.compareTo(this.row, m.getRow());
      if (res != 0) {
        throw new WrongRowIOException("The row in the recently added Put/Delete <" +
            Bytes.toStringBinary(m.getRow()) + "> doesn't match the original one <" +
            Bytes.toStringBinary(this.row) + ">");
      }
      mutations.add(m);
    }
  
    @Override
    public int compareTo(Row i) {
      return Bytes.compareTo(this.getRow(), i.getRow());
    }
  
    @Override
    public boolean equals(Object obj) {
      if (obj == this) return true;
      if (obj instanceof RowMutations) {
        RowMutations other = (RowMutations)obj;
        return compareTo(other) == 0;
      }
      return false;
    }
 
   @Override
   public int hashCode(){
     return Arrays.hashCode(row);
   }
 
   @Override
   public byte[] getRow() {
     return row;
   }
 
   /**
    * @return An unmodifiable list of the current mutations.
    */
   public List<Mutation> getMutations() {
     return Collections.unmodifiableList(mutations);
   }
 }