1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with this
4 * work for additional information regarding copyright ownership. The ASF
5 * licenses this file to you under the Apache License, Version 2.0 (the
6 * "License"); you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14 * License for the specific language governing permissions and limitations
15 * under the License.
16 */
17 package org.apache.hadoop.hbase.io.encoding;
18
19 import java.io.IOException;
20
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.io.hfile.BlockType;
23 import org.apache.hadoop.hbase.io.hfile.HFileContext;
24 import org.apache.hadoop.hbase.util.Bytes;
25
26 /**
27 * An encoding context that is created by a writer's encoder, and is shared
28 * across the writer's whole lifetime.
29 *
30 * @see HFileBlockDecodingContext for decoding
31 *
32 */
33 @InterfaceAudience.Private
34 public interface HFileBlockEncodingContext {
35
36 /**
37 * @return the block type after encoding
38 */
39 BlockType getBlockType();
40
41 /**
42 * @return the {@link DataBlockEncoding} encoding used
43 */
44 DataBlockEncoding getDataBlockEncoding();
45
46 /**
47 * Do any action that needs to be performed after the encoding.
48 * Compression is also included if a non-null compression algorithm is used
49 *
50 * @param blockType
51 * @throws IOException
52 */
53 void postEncoding(BlockType blockType) throws IOException;
54
55 /**
56 * Releases the resources used.
57 */
58 void close();
59
60 /**
61 * @return HFile context information
62 */
63 HFileContext getHFileContext();
64
65 /**
66 * Sets the encoding state.
67 * @param state
68 */
69 void setEncodingState(EncodingState state);
70
71 /**
72 * @return the encoding state
73 */
74 EncodingState getEncodingState();
75
76 /**
77 * @param data encoded bytes with header
78 * @param offset the offset in encoded data to start at
79 * @param length the number of encoded bytes
80 * @return Bytes with header which are ready to write out to disk.
81 * This is compressed and encrypted bytes applying the set compression
82 * algorithm and encryption. The bytes may be changed.
83 * If need a Bytes reference for later use, clone the bytes and use that.
84 * Null if the data doesn't need to be compressed and encrypted.
85 */
86 Bytes compressAndEncrypt(byte[] data, int offset, int length) throws IOException;
87 }