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Tomcat10 Slf4j Logback Integration
/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2015, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package org.apache.juli.logging.ch.qos.logback.core.util;
import java.time.Instant;
import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
import java.util.concurrent.atomic.AtomicReference;
/**
* A CAS implementation of DateTimeFormatter (previously SimpleDateFormat) which
* caches results for the duration of a millisecond.
*
* @author Ceki Gülcü
* @since 0.9.29
*/
public class CachingDateFormatter {
final DateTimeFormatter dtf;
final ZoneId zoneId;
final AtomicReference atomicReference;
static class CacheTuple {
final long lastTimestamp;
final String cachedStr;
public CacheTuple(long lastTimestamp, String cachedStr) {
super();
this.lastTimestamp = lastTimestamp;
this.cachedStr = cachedStr;
}
}
public CachingDateFormatter(String pattern) {
this(pattern, null);
}
public CachingDateFormatter(String pattern, ZoneId aZoneId) {
this(pattern, aZoneId, null);
}
public CachingDateFormatter(String pattern, ZoneId aZoneId, Locale aLocale) {
if (aZoneId == null) {
this.zoneId = ZoneId.systemDefault();
} else {
this.zoneId = aZoneId;
}
Locale locale = aLocale != null ? aLocale : Locale.getDefault();
dtf = DateTimeFormatter.ofPattern(pattern).withZone(this.zoneId).withLocale(locale);
CacheTuple cacheTuple = new CacheTuple(-1, null);
this.atomicReference = new AtomicReference<>(cacheTuple);
}
public final String format(long now) {
CacheTuple localCacheTuple = atomicReference.get();
CacheTuple oldCacheTuple = localCacheTuple;
if (now != localCacheTuple.lastTimestamp) {
Instant instant = Instant.ofEpochMilli(now);
String result = dtf.format(instant);
localCacheTuple = new CacheTuple(now, result);
// allow a single thread to update the cache reference
atomicReference.compareAndSet(oldCacheTuple, localCacheTuple);
}
return localCacheTuple.cachedStr;
}
}