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Posted to dev@tomcat.apache.org by al...@locus.apache.org on 2000/07/11 05:01:57 UTC
cvs commit: jakarta-tomcat/src/share/org/apache/tomcat/util FastDateFormat.java
alex 00/07/10 20:01:57
Added: src/share/org/apache/tomcat/util FastDateFormat.java
Log:
Fast date formatter that caches recently formatted date information
and uses it to avoid too-frequent calls to the underlying
formatter.
Original code thanks to Stan Bailes
Alex made it actually extend DateFormat (so you can theoretically use
it anywhere you would use a SimpleDateFormat) and tried unsuccessfully
to work around a bug in SimpleDateFormat involving msec FieldPosition
Revision Changes Path
1.1 jakarta-tomcat/src/share/org/apache/tomcat/util/FastDateFormat.java
Index: FastDateFormat.java
===================================================================
/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* Original code Copyright 2000 Quadcap Software:
* This software may be freely redistributed in source or binary form
* for any purpose.
*
*/
package org.apache.tomcat.util;
import java.util.Date;
import java.text.DateFormat;
import java.text.FieldPosition;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
/**
* Fast date formatter that caches recently formatted date information
* and uses it to avoid too-frequent calls to the underlying
* formatter. Note: breaks fieldPosition param of format(Date,
* StringBuffer, FieldPosition). If you care about the field
* position, call the underlying DateFormat directly.
*
* @author Stan Bailes
* @author Alex Chaffee
**/
public class FastDateFormat extends DateFormat {
DateFormat df;
long lastSec = -1;
StringBuffer sb = new StringBuffer();
FieldPosition fp = new FieldPosition(DateFormat.MILLISECOND_FIELD);
public FastDateFormat(DateFormat df) {
this.df = df;
}
public Date parse(String text, ParsePosition pos) {
return df.parse(text, pos);
}
/**
* Note: breaks functionality of fieldPosition param. Also:
* there's a bug in SimpleDateFormat with "S" and "SS", use "SSS"
* instead if you want a msec field.
**/
public StringBuffer format(Date date, StringBuffer toAppendTo,
FieldPosition fieldPosition) {
long dt = date.getTime();
long ds = dt / 1000;
if (ds != lastSec) {
sb.setLength(0);
df.format(date, sb, fp);
lastSec = ds;
} else {
// munge current msec into existing string
int ms = (int)(dt % 1000);
int pos = fp.getEndIndex();
int begin = fp.getBeginIndex();
if (pos > 0) {
if (pos > begin)
sb.setCharAt(--pos, Character.forDigit(ms % 10, 10));
ms /= 10;
if (pos > begin)
sb.setCharAt(--pos, Character.forDigit(ms % 10, 10));
ms /= 10;
if (pos > begin)
sb.setCharAt(--pos, Character.forDigit(ms % 10, 10));
}
}
toAppendTo.append(sb.toString());
return toAppendTo;
}
public static void main(String[] args) {
String format = "yyyy-MM-dd HH:mm:ss.SSS";
if (args.length > 0)
format = args[0];
SimpleDateFormat sdf = new SimpleDateFormat(format);
FastDateFormat fdf = new FastDateFormat(sdf);
Date d = new Date();
d.setTime(1); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(20); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(500); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(543); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(999); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(1050); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(2543); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(12345); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
d.setTime(12340); System.out.println(fdf.format(d) + "\t" + sdf.format(d));
final int reps = 100000;
{
long start = System.currentTimeMillis();
for (int i = 0; i < reps; i++) {
d.setTime(System.currentTimeMillis());
fdf.format(d);
}
long elap = System.currentTimeMillis() - start;
System.out.println("fast: " + elap + " elapsed");
System.out.println(fdf.format(d));
}
{
long start = System.currentTimeMillis();
for (int i = 0; i < reps; i++) {
d.setTime(System.currentTimeMillis());
sdf.format(d);
}
long elap = System.currentTimeMillis() - start;
System.out.println("slow: " + elap + " elapsed");
System.out.println(sdf.format(d));
}
}
}