log::log4perl::util::timetracker(3pm) [debian man page]

Util::TimeTracker(3pm)					User Contributed Perl Documentation				    Util::TimeTracker(3pm)

NAME

       Log::Log4perl::Util::TimeTracker - Track time elapsed

SYNOPSIS

	 use Log::Log4perl::Util::TimeTracker;

	 my $timer = Log::Log4perl::Util::TimeTracker->new();

	   # equivalent to Time::HiRes::gettimeofday(), regardless
	   # if Time::HiRes is present or not.
	 my($seconds, $microseconds) = $timer->gettimeofday();

	   # reset internal timer
	 $timer->reset();

	   # return milliseconds since last reset
	 $msecs = $timer->milliseconds();

	   # return milliseconds since last call
	 $msecs = $timer->delta_milliseconds();

DESCRIPTION

       This utility module helps tracking time elapsed for PatternLayout's date and time placeholders. Its accuracy depends on the availability of
       the Time::HiRes module. If it's available, its granularity is milliseconds, if not, seconds.

       The most common use of this module is calling the gettimeofday() method:

	 my($seconds, $microseconds) = $timer->gettimeofday();

       It returns seconds and microseconds of the current epoch time. If Time::HiRes is installed, it will simply defer to its gettimeofday()
       function, if it's missing, time() will be called instead and $microseconds will always be 0.

       To measure time elapsed in milliseconds, use the reset() method to reset the timer to the current time, followed by one or more calls to
       the milliseconds() method:

	   # reset internal timer
	 $timer->reset();

	   # return milliseconds since last reset
	 $msecs = $timer->milliseconds();

       On top of the time span between the last reset and the current time, the module keeps track of the time between calls to
       delta_milliseconds():

	 $msecs = $timer->delta_milliseconds();

       On the first call, this will return the number of milliseconds since the last reset(), on subsequent calls, it will return the time elapsed
       in milliseconds since the last call to delta_milliseconds() instead. Note that reset() also resets the time of the last call.

       The internal timer of this module gets its time input from the POSIX time() function, or, if the Time::HiRes module is available, from its
       gettimeofday() function. To figure out which one it is, use

	   if( $timer->hires_available() ) {
	       print "Hooray, we get real milliseconds!
";
	   } else {
	       print "Milliseconds are just bogus
";
	   }

       For testing purposes, a different time source can be provided, so test suites can simulate time passing by without actually having to wait:

	 my $start_time = time();

	 my $timer = Log::Log4perl::Util::TimeTracker->new(
		 time_function => sub {
		     return $start_time++;
		 },
	 );

       Every call to $timer->epoch() will then return a time value that is one second ahead of the the value returned on the previous call. This
       also means that every call to delta_milliseconds() will return a value that exceeds the value returned on the previous call by 1000.

COPYRIGHT AND LICENSE

       Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.10.1							    2010-07-21						    Util::TimeTracker(3pm)

DateFormat(3pm) 					User Contributed Perl Documentation					   DateFormat(3pm)

NAME

       Log::Log4perl::DateFormat - Log4perl advanced date formatter helper class

SYNOPSIS

	   use Log::Log4perl::DateFormat;

	   my $format = Log::Log4perl::DateFormat->new("HH:mm:ss,SSS");

	   # Simple time, resolution in seconds
	   my $time = time();
	   print $format->format($time), "
";
	       # => "17:02:39,000"

	   # Advanced time, resultion in milliseconds
	   use Time::HiRes;
	   my ($secs, $msecs) = Time::HiRes::gettimeofday();
	   print $format->format($secs, $msecs), "
";
	       # => "17:02:39,959"

DESCRIPTION

       "Log::Log4perl::DateFormat" is a low-level helper class for the advanced date formatting functions in
       "Log::Log4perl::Layout::PatternLayout".

       Unless you're writing your own Layout class like Log::Log4perl::Layout::PatternLayout, there's probably not much use for you to read this.

       "Log::Log4perl::DateFormat" is a formatter which allows dates to be formatted according to the log4j spec on

	   http://java.sun.com/j2se/1.5.0/docs/api/java/text/SimpleDateFormat.html

       which allows the following placeholders to be recognized and processed:

	   Symbol Meaning	       Presentation    Example
	   ------ -------	       ------------    -------
	   G	  era designator       (Text)	       AD
	   y	  year		       (Number)        1996
	   M	  month in year        (Text & Number) July & 07
	   d	  day in month	       (Number)        10
	   h	  hour in am/pm (1~12) (Number)        12
	   H	  hour in day (0~23)   (Number)        0
	   m	  minute in hour       (Number)        30
	   s	  second in minute     (Number)        55
	   S	  millisecond	       (Number)        978
	   E	  day in week	       (Text)	       Tuesday
	   D	  day in year	       (Number)        189
	   F	  day of week in month (Number)        2 (2nd Wed in July)
	   w	  week in year	       (Number)        27
	   W	  week in month        (Number)        2
	   a	  am/pm marker	       (Text)	       PM
	   k	  hour in day (1~24)   (Number)        24
	   K	  hour in am/pm (0~11) (Number)        0
	   z	  time zone	       (Text)	       Pacific Standard Time
	   Z	  RFC 822 time zone    (Text)	       -0800
	   '	  escape for text      (Delimiter)
	   ''	  single quote	       (Literal)       '

       For example, if you want to format the current Unix time in "MM/dd HH:mm" format, all you have to do is this:

	   use Log::Log4perl::DateFormat;

	   my $format = Log::Log4perl::DateFormat->new("MM/dd HH:mm");

	   my $time = time();
	   print $format->format($time), "
";

       While the "new()" method is expensive, because it parses the format strings and sets up all kinds of structures behind the scenes, followup
       calls to "format()" are fast, because "DateFormat" will just call "localtime()" and "sprintf()" once to return the formatted date/time
       string.

       So, typically, you would initialize the formatter once and then reuse it over and over again to display all kinds of time values.

       Also, for your convenience, the following predefined formats are available, just as outlined in the log4j spec:

	   Format   Equivalent			   Example
	   ABSOLUTE "HH:mm:ss,SSS"		   "15:49:37,459"
	   DATE     "dd MMM yyyy HH:mm:ss,SSS"	   "06 Nov 1994 15:49:37,459"
	   ISO8601  "yyyy-MM-dd HH:mm:ss,SSS"	   "1999-11-27 15:49:37,459"
	   APACHE   "[EEE MMM dd HH:mm:ss yyyy]"   "[Wed Mar 16 15:49:37 2005]"

       So, instead of passing

	   Log::Log4perl::DateFormat->new("HH:mm:ss,SSS");

       you could just as well say

	   Log::Log4perl::DateFormat->new("ABSOLUTE");

       and get the same result later on.

   Known Shortcomings
       The following placeholders are currently not recognized, unless someone (and that could be you :) implements them:

	   F day of week in month
	   w week in year
	   W week in month
	   k hour in day
	   K hour in am/pm
	   z timezone (but we got 'Z' for the numeric time zone value)

       Also, "Log::Log4perl::DateFormat" just knows about English week and month names, internationalization support has to be added.

COPYRIGHT AND LICENSE

       Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.10.1							    2010-07-21							   DateFormat(3pm)