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[log4perl-devel] Fwd: Timezone offset support for Log::Log4perl::DateFormat
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From: Mike S. <msc...@ao...> - 2003-08-28 01:15:18
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-------- Original Message --------
Subject: Timezone offset support for Log::Log4perl::DateFormat
Date: 8/27/2003, 4:00 PM
From: Mac Yang <ma...@pr...>
To: log...@pe...
Hi,
I have added the support for timezone offset (the Z option). Please take
a look and let me know if you could incorporate the offset support into
the next release.
On a separate thread, is it safe to use log4perl (with FileRotate
appender) with a program that forks subprocesses (log4perl are called
from both the parent and children processes)? Does log4perl performs any
sort of file locking? There was a similar question posted to the
log4j-user list about a month ago, but no answer so far.
Thanks in advance,
mac
###########################################
package Log::Log4perl::DateFormat;
###########################################
use warnings;
use strict;
our $GMTIME = 0;
my @MONTH_NAMES = qw(
January February March April May June July
August September October November December);
my @WEEK_DAYS = qw(
Sunday Monday Tuesday Wednesday Thursday Friday);
###########################################
sub new {
###########################################
my($class, $format) = @_;
my $self = {
stack => [],
fmt => undef,
};
bless $self, $class;
# Predefined formats
if($format eq "ABSOLUTE") {
$format = "HH:mm:ss,SSS";
} elsif($format eq "DATE") {
$format = "dd MMM yyyy HH:mm:ss,SSS";
} elsif($format eq "ISO8601") {
$format = "yyyy-MM-dd HH:mm:ss,SSS";
}
if($format) {
$self->prepare($format);
}
return $self;
}
###########################################
sub prepare {
###########################################
my($self, $format) = @_;
$format =~ s/(([GyMdhHmsSEDFwWakKzZ])\2*)/rep($self, $1)/ge;
$self->{fmt} = $format;
}
###########################################
sub rep {
###########################################
my ($self, $string) = @_;
my $first = substr $string, 0, 1;
my $len = length $string;
my $time=time();
my @g = gmtime($time);
my @t = localtime($time);
my $z =
$t[1]-$g[1]+($t[2]-$g[2])*60+($t[7]-$g[7])*1440+($t[5]-$g[5])*525600;
my $offset = sprintf("%+.2d%.2d", $z/60, "00");
#my ($s,$mi,$h,$d,$mo,$y,$wd,$yd,$dst) = localtime($time);
# Here's how this works:
# Detect what kind of parameter we're dealing with and determine
# what type of sprintf-placeholder to return (%d, %02d, %s or
whatever).
# Then, we're setting up an array, specific to the current format,
# that can be used later on to compute the components of the
placeholders
# one by one when we get the components of the current time later on
# via localtime.
# So, we're parsing the "yyyy/MM" format once, replace it by, say
# "%04d:%02d" and store an array that says "for the first placeholder,
# get the localtime-parameter on index #5 (which is years since the
# epoch), add 1900 to it and pass it on to sprintf(). For the 2nd
# placeholder, get the localtime component at index #2 (which is hours)
# and pass it on unmodified to sprintf.
# So, the array to compute the time format at logtime contains
# as many elements as the original SimpleDateFormat contained. Each
# entry is a arrary ref, holding an array with 2 elements: The index
# into the localtime to obtain the value and a reference to a
subroutine
# to do computations eventually. The subroutine expects the orginal
# localtime() time component (like year since the epoch) and returns
# the desired value for sprintf (like y+1900).
# This way, we're parsing the original format only once (during system
# startup) and during runtime all we do is call localtime *once* and
# run a number of blazingly fast computations, according to the number
# of placeholders in the format.
###########
#G - epoch#
###########
if($first eq "G") {
# Always constant
return "AD";
##########
#y - year#
##########
} elsif($first eq "y") {
if($len >= 4) {
# 4-digit year
push @{$self->{stack}}, [5, sub { return $_[0] + 1900 }];
return "%04d";
} else {
# 2-digit year
push @{$self->{stack}}, [5, sub { $_[0] % 100 }];
return "%02d";
}
###########
#M - month#
###########
} elsif($first eq "M") {
if($len >= 3) {
# Use month name
push @{$self->{stack}}, [4, sub { return $MONTH_NAMES[$_[0]]
}];
return "%s";
} elsif($len == 2) {
# Use zero-padded month number
push @{$self->{stack}}, [4, sub { $_[0]+1 }];
return "%02d";
} else {
# Use zero-padded month number
push @{$self->{stack}}, [4, sub { $_[0]+1 }];
return "%d";
}
##################
#d - day of month#
##################
} elsif($first eq "d") {
push @{$self->{stack}}, [3, sub { return $_[0] }];
return "%0" . $len . "d";
##################
#h - am/pm hour#
##################
} elsif($first eq "h") {
push @{$self->{stack}}, [2, sub { ($_[0] % 12) || 12 }];
return "%0" . $len . "d";
##################
#H - 24 hour#
##################
} elsif($first eq "H") {
push @{$self->{stack}}, [2, sub { return $_[0] }];
return "%0" . $len . "d";
##################
#m - minute#
##################
} elsif($first eq "m") {
push @{$self->{stack}}, [1, sub { return $_[0] }];
return "%0" . $len . "d";
##################
#s - second#
##################
} elsif($first eq "s") {
push @{$self->{stack}}, [0, sub { return $_[0] }];
return "%0" . $len . "d";
##################
#E - day of week #
##################
} elsif($first eq "E") {
push @{$self->{stack}}, [6, sub { $WEEK_DAYS[$_[0]] }];
return "%${len}s";
######################
#D - day of the year #
######################
} elsif($first eq "D") {
push @{$self->{stack}}, [7, sub { $_[0] }];
return "%${len}s";
######################
#a - am/pm marker #
######################
} elsif($first eq "a") {
push @{$self->{stack}}, [2, sub { $_[0] < 12 ? "AM" : "PM" }];
return "%${len}s";
######################
#S - milliseconds #
######################
} elsif($first eq "S") {
push @{$self->{stack}},
[9, sub { substr sprintf("%06d", $_[0]), 0, $len }];
return "%s";
###############################
#Z - RFC 822 time zone -0800 #
###############################
} elsif($first eq "Z") {
push @{$self->{stack}}, [10, sub { $offset }];
return "$offset";
#############################
#Something that's not defined
#(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
#############################
} else {
return "-- '$first' not (yet) implemented --";
}
return $string;
}
###########################################
sub format {
###########################################
my($self, $secs, $msecs) = @_;
$msecs = 0 unless defined $msecs;
my @time;
if($GMTIME) {
@time = gmtime($secs);
} else {
@time = localtime($secs);
}
# add milliseconds
push @time, $msecs;
my @values = ();
for(@{$self->{stack}}) {
my($val, $code) = @$_;
if($code) {
push @values, $code->($time[$val]);
} else {
push @values, $time[$val];
}
}
return sprintf($self->{fmt}, @values);
}
1;
__END__
=head1 NAME
Log::Log4perl::DateFormat - Log4perl advanced date formatter helper class
=head1 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), "\n";
# => "17:02:39,000"
# Advanced time, resultion in milliseconds
use Time::HiRes;
my ($secs, $msecs) = Time::HiRes::gettimeofday();
print $format->format($secs, $msecs), "\n";
# => "17:02:39,959"
=head1 DESCRIPTION
C<Log::Log4perl::DateFormat> is a low-level helper class for the
advanced date formatting functions in
C<Log::Log4perl::Layout::PatternLayout>.
Unless you're writing your own Layout class like
L<Log::Log4perl::Layout::PatternLayout>, there's probably not much use
for you to read this.
C<Log::Log4perl::DateFormat> is a formatter which allows dates to be
formatted according to the log4j spec on
http://jakarta.apache.org/log4j/docs/api/org/apache/log4j/PatternLayout.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
' escape for text (Delimiter)
'' single quote (Literal) '
For example, if you want to format the current Unix time in
C<"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), "\n";
While the C<new()> method is expensive, because it parses the format
strings and sets up all kinds of structures behind the scenes,
followup calls to C<format()> are fast, because C<DateFormat> will
just call C<localtime()> and C<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"
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.
=head2 Known Shortcomings
The following placeholders are currently I<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
Also, C<Log::Log4perl::DateFormat> just knows about English week and
month names, internationalization support has to be added.
=head1 SEE ALSO
=head1 AUTHOR
Mike Schilli, <log...@pe...>
=cut
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