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.ipc;
19
20 import java.util.List;
21
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23 import org.apache.hadoop.hbase.CellScannable;
24 import org.apache.hadoop.hbase.CellScanner;
25 import org.apache.hadoop.hbase.CellUtil;
26 import org.apache.hadoop.hbase.HConstants;
27 import org.apache.hadoop.hbase.TableName;
28
29 /**
30 * Optionally carries Cells across the proxy/service interface down into ipc. On its
31 * way out it optionally carries a set of result Cell data. We stick the Cells here when we want
32 * to avoid having to protobuf them. This class is used ferrying data across the proxy/protobuf
33 * service chasm. Used by client and server ipc'ing.
34 */
35 @InterfaceAudience.Private
36 public class PayloadCarryingRpcController
37 extends TimeLimitedRpcController implements CellScannable {
38
39 public static final int PRIORITY_UNSET = -1;
40 /**
41 * Priority to set on this request. Set it here in controller so available composing the
42 * request. This is the ordained way of setting priorities going forward. We will be
43 * undoing the old annotation-based mechanism.
44 */
45 private int priority = PRIORITY_UNSET;
46
47 /**
48 * They are optionally set on construction, cleared after we make the call, and then optionally
49 * set on response with the result. We use this lowest common denominator access to Cells because
50 * sometimes the scanner is backed by a List of Cells and other times, it is backed by an
51 * encoded block that implements CellScanner.
52 */
53 private CellScanner cellScanner;
54
55 public PayloadCarryingRpcController() {
56 this((CellScanner)null);
57 }
58
59 public PayloadCarryingRpcController(final CellScanner cellScanner) {
60 this.cellScanner = cellScanner;
61 }
62
63 public PayloadCarryingRpcController(final List<CellScannable> cellIterables) {
64 this.cellScanner = cellIterables == null? null: CellUtil.createCellScanner(cellIterables);
65 }
66
67 /**
68 * @return One-shot cell scanner (you cannot back it up and restart)
69 */
70 @Override
71 public CellScanner cellScanner() {
72 return cellScanner;
73 }
74
75 public void setCellScanner(final CellScanner cellScanner) {
76 this.cellScanner = cellScanner;
77 }
78
79 /**
80 * @param priority Priority for this request; should fall roughly in the range
81 * {@link HConstants#NORMAL_QOS} to {@link HConstants#HIGH_QOS}
82 */
83 public void setPriority(int priority) {
84 this.priority = priority;
85 }
86
87 /**
88 * @param tn Set priority based off the table we are going against.
89 */
90 public void setPriority(final TableName tn) {
91 this.priority =
92 (tn != null && tn.isSystemTable())? HConstants.SYSTEMTABLE_QOS: HConstants.NORMAL_QOS;
93 }
94
95 /**
96 * @return The priority of this request
97 */
98 public int getPriority() {
99 return priority;
100 }
101
102 @Override public void reset() {
103 super.reset();
104 priority = 0;
105 cellScanner = null;
106 }
107 }