1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. 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,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.log4j.pattern;
19
20 import org.apache.log4j.spi.LoggingEvent;
21
22
23 /**
24 * Return the relative time in milliseconds since loading of the LoggingEvent
25 * class.
26 *
27 * @author Ceki Gülcü
28 */
29 public class RelativeTimePatternConverter extends LoggingEventPatternConverter {
30 /**
31 * Cached formatted timestamp.
32 */
33 private CachedTimestamp lastTimestamp = new CachedTimestamp(0, "");
34
35 /**
36 * Private constructor.
37 */
38 public RelativeTimePatternConverter() {
39 super("Time", "time");
40 }
41
42 /**
43 * Obtains an instance of RelativeTimePatternConverter.
44 * @param options options, currently ignored, may be null.
45 * @return instance of RelativeTimePatternConverter.
46 */
47 public static RelativeTimePatternConverter newInstance(
48 final String[] options) {
49 return new RelativeTimePatternConverter();
50 }
51
52 /**
53 * {@inheritDoc}
54 */
55 public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
56 long timestamp = event.timeStamp;
57
58 if (!lastTimestamp.format(timestamp, toAppendTo)) {
59 final String formatted =
60 Long.toString(timestamp - LoggingEvent.getStartTime());
61 toAppendTo.append(formatted);
62 lastTimestamp = new CachedTimestamp(timestamp, formatted);
63 }
64 }
65
66 /**
67 * Cached timestamp and formatted value.
68 */
69 private static final class CachedTimestamp {
70 /**
71 * Cached timestamp.
72 */
73 private final long timestamp;
74
75 /**
76 * Cached formatted timestamp.
77 */
78 private final String formatted;
79
80 /**
81 * Creates a new instance.
82 * @param timestamp timestamp.
83 * @param formatted formatted timestamp.
84 */
85 public CachedTimestamp(long timestamp, final String formatted) {
86 this.timestamp = timestamp;
87 this.formatted = formatted;
88 }
89
90 /**
91 * Appends the cached formatted timestamp to the buffer if timestamps match.
92 * @param newTimestamp requested timestamp.
93 * @param toAppendTo buffer to append formatted timestamp.
94 * @return true if requested timestamp matched cached timestamp.
95 */
96 public boolean format(long newTimestamp, final StringBuffer toAppendTo) {
97 if (newTimestamp == timestamp) {
98 toAppendTo.append(formatted);
99
100 return true;
101 }
102
103 return false;
104 }
105 }
106 }