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.metrics;
19
20 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.classification.InterfaceStability;
23
24 /**
25 * A metric which measures the distribution of values.
26 */
27 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
28 @InterfaceStability.Evolving
29 public interface Histogram extends Metric {
30
31 /**
32 * Adds a new value to the distribution.
33 *
34 * @param value The value to add
35 */
36 void update(int value);
37
38 /**
39 * Adds a new value to the distribution.
40 *
41 * @param value The value to add
42 */
43 void update(long value);
44
45 /**
46 * Return the total number of values added to the histogram.
47 * @return the total number of values.
48 */
49 long getCount();
50
51 /**
52 * Snapshot the current values in the Histogram
53 * @return a Snapshot of the distribution.
54 */
55 @InterfaceAudience.Private
56 Snapshot snapshot();
57
58 }