1 /**
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19 package org.apache.hadoop.hbase.filter;
20
21 import org.apache.hadoop.hbase.util.ByteStringer;
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23 import org.apache.hadoop.hbase.classification.InterfaceStability;
24 import org.apache.hadoop.hbase.exceptions.DeserializationException;
25 import org.apache.hadoop.hbase.protobuf.generated.ComparatorProtos;
26 import org.apache.hadoop.hbase.util.Bytes;
27
28
29 /** Base class for byte array comparators */
30 @InterfaceAudience.Public
31 @InterfaceStability.Stable
32 public abstract class ByteArrayComparable implements Comparable<byte[]> {
33
34 byte[] value;
35
36 /**
37 * Constructor.
38 * @param value the value to compare against
39 */
40 public ByteArrayComparable(byte [] value) {
41 this.value = value;
42 }
43
44 public byte[] getValue() {
45 return value;
46 }
47
48 /**
49 * @return The comparator serialized using pb
50 */
51 public abstract byte [] toByteArray();
52
53 ComparatorProtos.ByteArrayComparable convert() {
54 ComparatorProtos.ByteArrayComparable.Builder builder =
55 ComparatorProtos.ByteArrayComparable.newBuilder();
56 if (value != null) builder.setValue(ByteStringer.wrap(value));
57 return builder.build();
58 }
59
60 /**
61 * @param pbBytes A pb serialized {@link ByteArrayComparable} instance
62 * @return An instance of {@link ByteArrayComparable} made from <code>bytes</code>
63 * @throws DeserializationException
64 * @see #toByteArray
65 */
66 public static ByteArrayComparable parseFrom(final byte [] pbBytes)
67 throws DeserializationException {
68 throw new DeserializationException(
69 "parseFrom called on base ByteArrayComparable, but should be called on derived type");
70 }
71
72 /**
73 * @param other
74 * @return true if and only if the fields of the comparator that are serialized
75 * are equal to the corresponding fields in other. Used for testing.
76 */
77 boolean areSerializedFieldsEqual(ByteArrayComparable other) {
78 if (other == this) return true;
79
80 return Bytes.equals(this.getValue(), other.getValue());
81 }
82
83 @Override
84 public int compareTo(byte [] value) {
85 return compareTo(value, 0, value.length);
86 }
87
88 /**
89 * Special compareTo method for subclasses, to avoid
90 * copying byte[] unnecessarily.
91 * @param value byte[] to compare
92 * @param offset offset into value
93 * @param length number of bytes to compare
94 * @return a negative integer, zero, or a positive integer as this object
95 * is less than, equal to, or greater than the specified object.
96 */
97 public abstract int compareTo(byte [] value, int offset, int length);
98 }