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 import java.io.OutputStream;
21
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23 import org.apache.hadoop.hbase.io.hfile.BlockType;
24 import org.apache.hadoop.hbase.io.hfile.HFileContext;
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 OutputStream to which encoded data is written
38 */
39 OutputStream getOutputStreamForEncoder();
40
41 /**
42 * @return encoded and compressed bytes with header which are ready to write
43 * out to disk
44 */
45 byte[] getOnDiskBytesWithHeader();
46
47 /**
48 * @return encoded but not heavily compressed bytes with header which can be
49 * cached in block cache
50 */
51 byte[] getUncompressedBytesWithHeader();
52
53 /**
54 * @return the block type after encoding
55 */
56 BlockType getBlockType();
57
58 /**
59 * sets the dummy header bytes
60 */
61 void setDummyHeader(byte[] headerBytes);
62
63 /**
64 * @return the {@link DataBlockEncoding} encoding used
65 */
66 DataBlockEncoding getDataBlockEncoding();
67
68 /**
69 * Do any action that needs to be performed after the encoding.
70 * Compression is also included if a non-null compression algorithm is used
71 *
72 * @param blockType
73 * @throws IOException
74 */
75 void postEncoding(BlockType blockType) throws IOException;
76
77 /**
78 * Releases the resources used.
79 */
80 void close();
81
82 /**
83 * @return HFile context information
84 */
85 HFileContext getHFileContext();
86 }