001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.log4j.pattern; 019 020import org.apache.log4j.spi.LoggingEvent; 021 022 023/** 024 * Return the relative time in milliseconds since loading of the LoggingEvent 025 * class. 026 * 027 * @author Ceki Gülcü 028 */ 029public class RelativeTimePatternConverter extends LoggingEventPatternConverter { 030 /** 031 * Cached formatted timestamp. 032 */ 033 private CachedTimestamp lastTimestamp = new CachedTimestamp(0, ""); 034 035 /** 036 * Private constructor. 037 */ 038 public RelativeTimePatternConverter() { 039 super("Time", "time"); 040 } 041 042 /** 043 * Obtains an instance of RelativeTimePatternConverter. 044 * @param options options, currently ignored, may be null. 045 * @return instance of RelativeTimePatternConverter. 046 */ 047 public static RelativeTimePatternConverter newInstance( 048 final String[] options) { 049 return new RelativeTimePatternConverter(); 050 } 051 052 /** 053 * {@inheritDoc} 054 */ 055 public void format(final LoggingEvent event, final StringBuffer toAppendTo) { 056 long timestamp = event.timeStamp; 057 058 if (!lastTimestamp.format(timestamp, toAppendTo)) { 059 final String formatted = 060 Long.toString(timestamp - LoggingEvent.getStartTime()); 061 toAppendTo.append(formatted); 062 lastTimestamp = new CachedTimestamp(timestamp, formatted); 063 } 064 } 065 066 /** 067 * Cached timestamp and formatted value. 068 */ 069 private static final class CachedTimestamp { 070 /** 071 * Cached timestamp. 072 */ 073 private final long timestamp; 074 075 /** 076 * Cached formatted timestamp. 077 */ 078 private final String formatted; 079 080 /** 081 * Creates a new instance. 082 * @param timestamp timestamp. 083 * @param formatted formatted timestamp. 084 */ 085 public CachedTimestamp(long timestamp, final String formatted) { 086 this.timestamp = timestamp; 087 this.formatted = formatted; 088 } 089 090 /** 091 * Appends the cached formatted timestamp to the buffer if timestamps match. 092 * @param newTimestamp requested timestamp. 093 * @param toAppendTo buffer to append formatted timestamp. 094 * @return true if requested timestamp matched cached timestamp. 095 */ 096 public boolean format(long newTimestamp, final StringBuffer toAppendTo) { 097 if (newTimestamp == timestamp) { 098 toAppendTo.append(formatted); 099 100 return true; 101 } 102 103 return false; 104 } 105 } 106}