/tags/release-0.0.0-rc0/hive/external/ql/src/java/org/apache/hadoop/hive/ql/exec/ByteWritable.java

/**
 * 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.hive.ql.exec;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.WritableComparator;

/**
 * ByteWritable.
 *
 */
public class ByteWritable implements WritableComparable {
  private int value;

  public void write(DataOutput out) throws IOException {
    out.writeByte(value);
  }

  public void readFields(DataInput in) throws IOException {
    value = in.readByte();
  }

  public ByteWritable(int b) {
    value = b & 0xff;
  }

  public ByteWritable() {
    value = 0;
  }

  public void set(int b) {
    value = b & 0xff;
  }

  /** Compares two ByteWritables. */
  public int compareTo(Object o) {
    int thisValue = value;
    int thatValue = ((ByteWritable) o).value;
    return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
  }

  @Override
  public boolean equals(Object o) {
    if (!(o instanceof ByteWritable)) {
      return false;
    }
    ByteWritable that = (ByteWritable) o;
    if (this == that) {
      return true;
    }

    if (value == that.value) {
      return true;
    } else {
      return false;
    }
  }

  @Override
  public int hashCode() {
    return (value);
  }

  /** A Comparator optimized for BytesWritable. */
  public static class Comparator extends WritableComparator {
    public Comparator() {
      super(ByteWritable.class);
    }

    /**
     * Compare the buffers in serialized form.
     */
    @Override
    public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
      /**
       * ok - we are implementing a dummy byte int a = b1[s1] & 0xff; int b =
       * b2[s1] & 0xff; if(a!=b) return a -b;
       */
      return 0;
    }
  }

  static {
    // register this comparator
    WritableComparator.define(ByteWritable.class, new Comparator());
  }
}