org.apache.hadoop.io.BinaryComparable Maven / Gradle / Ivy
/**
* 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.io;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Interface supported by {@link org.apache.hadoop.io.WritableComparable}
* types supporting ordering/permutation by a representative set of bytes.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public abstract class BinaryComparable implements Comparable {
/**
* Return n st bytes 0..n-1 from {#getBytes()} are valid.
*/
public abstract int getLength();
/**
* Return representative byte array for this instance.
*/
public abstract byte[] getBytes();
/**
* Compare bytes from {#getBytes()}.
* @see org.apache.hadoop.io.WritableComparator#compareBytes(byte[],int,int,byte[],int,int)
*/
@Override
public int compareTo(BinaryComparable other) {
if (this == other)
return 0;
return WritableComparator.compareBytes(getBytes(), 0, getLength(),
other.getBytes(), 0, other.getLength());
}
/**
* Compare bytes from {#getBytes()} to those provided.
*/
public int compareTo(byte[] other, int off, int len) {
return WritableComparator.compareBytes(getBytes(), 0, getLength(),
other, off, len);
}
/**
* Return true if bytes from {#getBytes()} match.
*/
@Override
public boolean equals(Object other) {
if (!(other instanceof BinaryComparable))
return false;
BinaryComparable that = (BinaryComparable)other;
if (this.getLength() != that.getLength())
return false;
return this.compareTo(that) == 0;
}
/**
* Return a hash of the bytes returned from {#getBytes()}.
* @see org.apache.hadoop.io.WritableComparator#hashBytes(byte[],int)
*/
@Override
public int hashCode() {
return WritableComparator.hashBytes(getBytes(), getLength());
}
}