/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.log4j.pattern;
import org.apache.log4j.spi.LoggingEvent;
/**
* Return the relative time in milliseconds since loading of the LoggingEvent
* class.
*
* @author Ceki Gülcü
*/
public class RelativeTimePatternConverter extends LoggingEventPatternConverter {
/**
* Cached formatted timestamp.
*/
private CachedTimestamp lastTimestamp = new CachedTimestamp(0, "");
/**
* Private constructor.
*/
public RelativeTimePatternConverter() {
super("Time", "time");
}
/**
* Obtains an instance of RelativeTimePatternConverter.
* @param options options, currently ignored, may be null.
* @return instance of RelativeTimePatternConverter.
*/
public static RelativeTimePatternConverter newInstance(
final String[] options) {
return new RelativeTimePatternConverter();
}
/**
* {@inheritDoc}
*/
public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
long timestamp = event.timeStamp;
if (!lastTimestamp.format(timestamp, toAppendTo)) {
final String formatted =
Long.toString(timestamp - LoggingEvent.getStartTime());
toAppendTo.append(formatted);
lastTimestamp = new CachedTimestamp(timestamp, formatted);
}
}
/**
* Cached timestamp and formatted value.
*/
private static final class CachedTimestamp {
/**
* Cached timestamp.
*/
private final long timestamp;
/**
* Cached formatted timestamp.
*/
private final String formatted;
/**
* Creates a new instance.
* @param timestamp timestamp.
* @param formatted formatted timestamp.
*/
public CachedTimestamp(long timestamp, final String formatted) {
this.timestamp = timestamp;
this.formatted = formatted;
}
/**
* Appends the cached formatted timestamp to the buffer if timestamps match.
* @param newTimestamp requested timestamp.
* @param toAppendTo buffer to append formatted timestamp.
* @return true if requested timestamp matched cached timestamp.
*/
public boolean format(long newTimestamp, final StringBuffer toAppendTo) {
if (newTimestamp == timestamp) {
toAppendTo.append(formatted);
return true;
}
return false;
}
}
}
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