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.KeyValue;
28 import org.apache.hadoop.hbase.KeyValueUtil;
29
30 /**
31 * Codec that does KeyValue version 1 serialization.
32 *
33 * <p>Encodes Cell as serialized in KeyValue with total length prefix.
34 * This is how KVs were serialized in Puts, Deletes and Results pre-0.96. Its what would
35 * happen if you called the Writable#write KeyValue implementation. This encoder will fail
36 * if the passed Cell is not an old-school pre-0.96 KeyValue. Does not copy bytes writing.
37 * It just writes them direct to the passed stream.
38 *
39 * <p>If you wrote two KeyValues to this encoder, it would look like this in the stream:
40 * <pre>
41 * length-of-KeyValue1 // A java int with the length of KeyValue1 backing array
42 * KeyValue1 backing array filled with a KeyValue serialized in its particular format
43 * length-of-KeyValue2
44 * KeyValue2 backing array
45 * </pre>
46 */
47 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
48 public class KeyValueCodec implements Codec {
49 public static class KeyValueEncoder extends BaseEncoder {
50 public KeyValueEncoder(final OutputStream out) {
51 super(out);
52 }
53
54 @Override
55 public void write(Cell cell) throws IOException {
56 checkFlushed();
57 // Do not write tags over RPC
58 KeyValueUtil.oswrite(cell, out, false);
59 }
60 }
61
62 public static class KeyValueDecoder extends BaseDecoder {
63 public KeyValueDecoder(final InputStream in) {
64 super(in);
65 }
66
67 protected Cell parseCell() throws IOException {
68 return KeyValue.iscreate(in);
69 }
70 }
71
72 /**
73 * Implementation depends on {@link InputStream#available()}
74 */
75 @Override
76 public Decoder getDecoder(final InputStream is) {
77 return new KeyValueDecoder(is);
78 }
79
80 @Override
81 public Encoder getEncoder(OutputStream os) {
82 return new KeyValueEncoder(os);
83 }
84 }