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 package org.apache.hadoop.hbase.codec;
19
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.io.OutputStream;
23
24 import org.apache.hadoop.hbase.classification.InterfaceAudience;
25 import org.apache.hadoop.hbase.Cell;
26 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
27 import org.apache.hadoop.hbase.KeyValueUtil;
28
29 /**
30 * Codec that does KeyValue version 1 serialization.
31 *
32 * <p>Encodes Cell as serialized in KeyValue with total length prefix.
33 * This is how KVs were serialized in Puts, Deletes and Results pre-0.96. Its what would
34 * happen if you called the Writable#write KeyValue implementation. This encoder will fail
35 * if the passed Cell is not an old-school pre-0.96 KeyValue. Does not copy bytes writing.
36 * It just writes them direct to the passed stream.
37 *
38 * <p>If you wrote two KeyValues to this encoder, it would look like this in the stream:
39 * <pre>
40 * length-of-KeyValue1 // A java int with the length of KeyValue1 backing array
41 * KeyValue1 backing array filled with a KeyValue serialized in its particular format
42 * length-of-KeyValue2
43 * KeyValue2 backing array
44 * </pre>
45 */
46 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
47 public class KeyValueCodec implements Codec {
48 public static class KeyValueEncoder extends BaseEncoder {
49 public KeyValueEncoder(final OutputStream out) {
50 super(out);
51 }
52
53 @Override
54 public void write(Cell cell) throws IOException {
55 checkFlushed();
56 // Do not write tags over RPC
57 KeyValueUtil.oswrite(cell, out, false);
58 }
59 }
60
61 public static class KeyValueDecoder extends BaseDecoder {
62 public KeyValueDecoder(final InputStream in) {
63 super(in);
64 }
65
66 @Override
67 protected Cell parseCell() throws IOException {
68 // No tags here
69 return KeyValueUtil.createKeyValueFromInputStream(in, false);
70 }
71 }
72
73 /**
74 * Implementation depends on {@link InputStream#available()}
75 */
76 @Override
77 public Decoder getDecoder(final InputStream is) {
78 return new KeyValueDecoder(is);
79 }
80
81 @Override
82 public Encoder getEncoder(OutputStream os) {
83 return new KeyValueEncoder(os);
84 }
85 }