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TimedLogger xref
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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  
19  package org.apache.giraph.utils;
20  
21  import org.apache.log4j.Logger;
22  
23  /**
24   * Print log messages only if the time is met.  Thread-safe.
25   */
26  public class TimedLogger {
27    /** Last time printed */
28    private volatile long lastPrint = System.currentTimeMillis();
29    /** Minimum interval of time to wait before printing */
30    private final int msecs;
31    /** Logger */
32    private final Logger log;
33  
34    /**
35     * Constructor of the timed logger
36     *
37     * @param msecs Msecs to wait before printing again
38     * @param log Logger to print to
39     */
40    public TimedLogger(int msecs, Logger log) {
41      this.msecs = msecs;
42      this.log = log;
43    }
44  
45    /**
46     * Print to the info log level if the minimum waiting time was reached.
47     *
48     * @param msg Message to print
49     */
50    public void info(String msg) {
51      if (isPrintable()) {
52        log.info(msg);
53      }
54    }
55  
56    /**
57     * Is the log message printable (minimum interval met)?
58     *
59     * @return True if the message is printable
60     */
61    public boolean isPrintable() {
62      if (System.currentTimeMillis() > lastPrint + msecs) {
63        lastPrint = System.currentTimeMillis();
64        return true;
65      }
66  
67      return false;
68    }
69  }