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.io.compress.Compression;
23 import org.apache.hadoop.hbase.io.hfile.BlockType;
24
25 /**
26 * An encoding context that is created by a writer's encoder, and is shared
27 * across the writer's whole lifetime.
28 *
29 * @see HFileBlockDecodingContext for decoding
30 *
31 */
32 public interface HFileBlockEncodingContext {
33
34 /**
35 * @return OutputStream to which encoded data is written
36 */
37 OutputStream getOutputStreamForEncoder();
38
39 /**
40 * @return encoded and compressed bytes with header which are ready to write
41 * out to disk
42 */
43 byte[] getOnDiskBytesWithHeader();
44
45 /**
46 * @return encoded but not heavily compressed bytes with header which can be
47 * cached in block cache
48 */
49 byte[] getUncompressedBytesWithHeader();
50
51 /**
52 * @return the block type after encoding
53 */
54 BlockType getBlockType();
55
56 /**
57 * @return the compression algorithm used by this encoding context
58 */
59 Compression.Algorithm getCompression();
60
61 /**
62 * sets the dummy header bytes
63 */
64 void setDummyHeader(byte[] headerBytes);
65
66 /**
67 * @return the {@link DataBlockEncoding} encoding used
68 */
69 DataBlockEncoding getDataBlockEncoding();
70
71 /**
72 * Do any action that needs to be performed after the encoding.
73 * Compression is also included if {@link #getCompression()} returns non-null
74 * compression algorithm
75 *
76 * @param blockType
77 * @throws IOException
78 */
79 void postEncoding(BlockType blockType) throws IOException;
80
81 /**
82 * Releases the resources used.
83 */
84 void close();
85
86 }