I remember reading somewhere (SDF javadoc?) that SDF instances are not thread-safe. I take it that means class instances could mean trouble.
Otis ----- Original Message ---- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, July 21, 2006 4:38:23 PM Subject: svn commit: r424449 - /lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java Author: dnaber Date: Fri Jul 21 13:38:23 2006 New Revision: 424449 URL: http://svn.apache.org/viewvc?rev=424449&view=rev Log: Don't re-create SimpleDateFormat objects, use static ones instead. Gives about a 2x performance increase in a micro benchmark. Modified: lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java Modified: lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java URL: http://svn.apache.org/viewvc/lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java?rev=424449&r1=424448&r2=424449&view=diff ============================================================================== --- lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java (original) +++ lucene/java/trunk/src/java/org/apache/lucene/document/DateTools.java Fri Jul 21 13:38:23 2006 @@ -40,6 +40,26 @@ private final static TimeZone GMT = TimeZone.getTimeZone("GMT"); + private static final SimpleDateFormat YEAR_FORMAT = new SimpleDateFormat("yyyy"); + private static final SimpleDateFormat MONTH_FORMAT = new SimpleDateFormat("yyyyMM"); + private static final SimpleDateFormat DAY_FORMAT = new SimpleDateFormat("yyyyMMdd"); + private static final SimpleDateFormat HOUR_FORMAT = new SimpleDateFormat("yyyyMMddHH"); + private static final SimpleDateFormat MINUTE_FORMAT = new SimpleDateFormat("yyyyMMddHHmm"); + private static final SimpleDateFormat SECOND_FORMAT = new SimpleDateFormat("yyyyMMddHHmmss"); + private static final SimpleDateFormat MILLISECOND_FORMAT = new SimpleDateFormat("yyyyMMddHHmmssSSS"); + static { + // times need to be normalized so the value doesn't depend on the + // location the index is created/used: + YEAR_FORMAT.setTimeZone(GMT); + MONTH_FORMAT.setTimeZone(GMT); + DAY_FORMAT.setTimeZone(GMT); + HOUR_FORMAT.setTimeZone(GMT); + MINUTE_FORMAT.setTimeZone(GMT); + SECOND_FORMAT.setTimeZone(GMT); + MILLISECOND_FORMAT.setTimeZone(GMT); + } + + // cannot create, the class has static methods only private DateTools() {} /** @@ -54,7 +74,7 @@ public static String dateToString(Date date, Resolution resolution) { return timeToString(date.getTime(), resolution); } - + /** * Converts a millisecond time to a string suitable for indexing. * @@ -72,30 +92,41 @@ cal.setTime(new Date(round(time, resolution))); - SimpleDateFormat sdf = new SimpleDateFormat(); - sdf.setTimeZone(GMT); - String pattern = null; + String result; if (resolution == Resolution.YEAR) { - pattern = "yyyy"; + synchronized (YEAR_FORMAT) { + result = YEAR_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.MONTH) { - pattern = "yyyyMM"; + synchronized (MONTH_FORMAT) { + result = MONTH_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.DAY) { - pattern = "yyyyMMdd"; + synchronized (DAY_FORMAT) { + result = DAY_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.HOUR) { - pattern = "yyyyMMddHH"; + synchronized (HOUR_FORMAT) { + result = HOUR_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.MINUTE) { - pattern = "yyyyMMddHHmm"; + synchronized (MINUTE_FORMAT) { + result = MINUTE_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.SECOND) { - pattern = "yyyyMMddHHmmss"; + synchronized (SECOND_FORMAT) { + result = SECOND_FORMAT.format(cal.getTime()); + } } else if (resolution == Resolution.MILLISECOND) { - pattern = "yyyyMMddHHmmssSSS"; + synchronized (MILLISECOND_FORMAT) { + result = MILLISECOND_FORMAT.format(cal.getTime()); + } } else { throw new IllegalArgumentException("unknown resolution " + resolution); } - sdf.applyPattern(pattern); - return sdf.format(cal.getTime()); + return result; } - + /** * Converts a string produced by <code>timeToString</code> or * <code>dateToString</code> back to a time, represented as the @@ -121,26 +152,38 @@ * expected format */ public static Date stringToDate(String dateString) throws ParseException { - String pattern = null; - if (dateString.length() == 4 ) - pattern = "yyyy"; - else if (dateString.length() == 6 ) - pattern = "yyyyMM"; - else if (dateString.length() == 8 ) - pattern = "yyyyMMdd"; - else if (dateString.length() == 10 ) - pattern = "yyyyMMddHH"; - else if (dateString.length() == 12 ) - pattern = "yyyyMMddHHmm"; - else if (dateString.length() == 14 ) - pattern = "yyyyMMddHHmmss"; - else if (dateString.length() == 17 ) - pattern = "yyyyMMddHHmmssSSS"; - else + Date date; + if (dateString.length() == 4) { + synchronized (YEAR_FORMAT) { + date = YEAR_FORMAT.parse(dateString); + } + } else if (dateString.length() == 6) { + synchronized (MONTH_FORMAT) { + date = MONTH_FORMAT.parse(dateString); + } + } else if (dateString.length() == 8) { + synchronized (DAY_FORMAT) { + date = DAY_FORMAT.parse(dateString); + } + } else if (dateString.length() == 10) { + synchronized (HOUR_FORMAT) { + date = HOUR_FORMAT.parse(dateString); + } + } else if (dateString.length() == 12) { + synchronized (MINUTE_FORMAT) { + date = MINUTE_FORMAT.parse(dateString); + } + } else if (dateString.length() == 14) { + synchronized (SECOND_FORMAT) { + date = SECOND_FORMAT.parse(dateString); + } + } else if (dateString.length() == 17) { + synchronized (MILLISECOND_FORMAT) { + date = MILLISECOND_FORMAT.parse(dateString); + } + } else { throw new ParseException("Input is not valid date string: " + dateString, 0); - SimpleDateFormat sdf = new SimpleDateFormat(pattern); - sdf.setTimeZone(GMT); - Date date = sdf.parse(dateString); + } return date; } --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
