1 /**
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19 package org.apache.hadoop.hbase.client;
20
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.classification.InterfaceStability;
23 import org.apache.hadoop.hbase.HRegionLocation;
24 import org.apache.hadoop.hbase.TableName;
25 import org.apache.hadoop.hbase.util.Pair;
26
27 import java.io.Closeable;
28 import java.io.IOException;
29 import java.util.List;
30
31 /**
32 * Used to view region location information for a single HBase table.
33 * Obtain an instance from an {@link Connection}.
34 *
35 * @see ConnectionFactory
36 * @see Connection
37 * @see Table
38 * @since 0.99.0
39 */
40 @InterfaceAudience.Public
41 @InterfaceStability.Evolving
42 public interface RegionLocator extends Closeable {
43 /**
44 * Finds the region on which the given row is being served. Does not reload the cache.
45 * @param row Row to find.
46 * @return Location of the row.
47 * @throws IOException if a remote or network exception occurs
48 */
49 public HRegionLocation getRegionLocation(final byte [] row) throws IOException;
50
51 /**
52 * Finds the region on which the given row is being served.
53 * @param row Row to find.
54 * @param reload true to reload information or false to use cached information
55 * @return Location of the row.
56 * @throws IOException if a remote or network exception occurs
57 */
58 public HRegionLocation getRegionLocation(final byte [] row, boolean reload)
59 throws IOException;
60
61 /**
62 * Retrieves all of the regions associated with this table.
63 * @return a {@link List} of all regions associated with this table.
64 * @throws IOException if a remote or network exception occurs
65 */
66 public List<HRegionLocation> getAllRegionLocations()
67 throws IOException;
68
69 /**
70 * Gets the starting row key for every region in the currently open table.
71 * <p>
72 * This is mainly useful for the MapReduce integration.
73 * @return Array of region starting row keys
74 * @throws IOException if a remote or network exception occurs
75 */
76 public byte [][] getStartKeys() throws IOException;
77
78 /**
79 * Gets the ending row key for every region in the currently open table.
80 * <p>
81 * This is mainly useful for the MapReduce integration.
82 * @return Array of region ending row keys
83 * @throws IOException if a remote or network exception occurs
84 */
85 public byte[][] getEndKeys() throws IOException;
86
87 /**
88 * Gets the starting and ending row keys for every region in the currently
89 * open table.
90 * <p>
91 * This is mainly useful for the MapReduce integration.
92 * @return Pair of arrays of region starting and ending row keys
93 * @throws IOException if a remote or network exception occurs
94 */
95 public Pair<byte[][],byte[][]> getStartEndKeys() throws IOException;
96
97 /**
98 * Gets the fully qualified table name instance of this table.
99 */
100 TableName getName();
101 }