1 | /** |
---|
2 | * Licensed to the Apache Software Foundation (ASF) under one |
---|
3 | * or more contributor license agreements. See the NOTICE file |
---|
4 | * distributed with this work for additional information |
---|
5 | * regarding copyright ownership. The ASF licenses this file |
---|
6 | * to you under the Apache License, Version 2.0 (the |
---|
7 | * "License"); you may not use this file except in compliance |
---|
8 | * with the License. You may obtain a copy of the License at |
---|
9 | * |
---|
10 | * http://www.apache.org/licenses/LICENSE-2.0 |
---|
11 | * |
---|
12 | * Unless required by applicable law or agreed to in writing, software |
---|
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
---|
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
---|
15 | * See the License for the specific language governing permissions and |
---|
16 | * limitations under the License. |
---|
17 | */ |
---|
18 | |
---|
19 | package org.apache.hadoop.io; |
---|
20 | |
---|
21 | /** |
---|
22 | * Interface supported by {@link org.apache.hadoop.io.WritableComparable} |
---|
23 | * types supporting ordering/permutation by a representative set of bytes. |
---|
24 | */ |
---|
25 | public abstract class BinaryComparable implements Comparable<BinaryComparable> { |
---|
26 | |
---|
27 | /** |
---|
28 | * Return n st bytes 0..n-1 from {#getBytes()} are valid. |
---|
29 | */ |
---|
30 | public abstract int getLength(); |
---|
31 | |
---|
32 | /** |
---|
33 | * Return representative byte array for this instance. |
---|
34 | */ |
---|
35 | public abstract byte[] getBytes(); |
---|
36 | |
---|
37 | /** |
---|
38 | * Compare bytes from {#getBytes()}. |
---|
39 | * @see org.apache.hadoop.io.WritableComparator#compareBytes(byte[],int,int,byte[],int,int) |
---|
40 | */ |
---|
41 | public int compareTo(BinaryComparable other) { |
---|
42 | if (this == other) |
---|
43 | return 0; |
---|
44 | return WritableComparator.compareBytes(getBytes(), 0, getLength(), |
---|
45 | other.getBytes(), 0, other.getLength()); |
---|
46 | } |
---|
47 | |
---|
48 | /** |
---|
49 | * Compare bytes from {#getBytes()} to those provided. |
---|
50 | */ |
---|
51 | public int compareTo(byte[] other, int off, int len) { |
---|
52 | return WritableComparator.compareBytes(getBytes(), 0, getLength(), |
---|
53 | other, off, len); |
---|
54 | } |
---|
55 | |
---|
56 | /** |
---|
57 | * Return true if bytes from {#getBytes()} match. |
---|
58 | */ |
---|
59 | public boolean equals(Object other) { |
---|
60 | if (!(other instanceof BinaryComparable)) |
---|
61 | return false; |
---|
62 | BinaryComparable that = (BinaryComparable)other; |
---|
63 | if (this.getLength() != that.getLength()) |
---|
64 | return false; |
---|
65 | return this.compareTo(that) == 0; |
---|
66 | } |
---|
67 | |
---|
68 | /** |
---|
69 | * Return a hash of the bytes returned from {#getBytes()}. |
---|
70 | * @see org.apache.hadoop.io.WritableComparator#hashBytes(byte[],int) |
---|
71 | */ |
---|
72 | public int hashCode() { |
---|
73 | return WritableComparator.hashBytes(getBytes(), getLength()); |
---|
74 | } |
---|
75 | |
---|
76 | } |
---|