| Current File : //proc/thread-self/root/usr/share/perl5/DateTime/TimeZone/OlsonDB.pm |
package DateTime::TimeZone::OlsonDB;
use strict;
use warnings;
use namespace::autoclean;
our $VERSION = '2.62';
use DateTime::Duration;
use DateTime::TimeZone::OlsonDB::Rule;
use DateTime::TimeZone::OlsonDB::Zone;
my $x = 1;
our %MONTHS = map { $_ => $x++ } qw( Jan Feb Mar Apr May Jun
Jul Aug Sep Oct Nov Dec);
$x = 1;
our %DAYS = map { $_ => $x++ } qw( Mon Tue Wed Thu Fri Sat Sun );
our $PLUS_ONE_DAY_DUR = DateTime::Duration->new( days => 1 );
our $MINUS_ONE_DAY_DUR = DateTime::Duration->new( days => -1 );
sub new {
my $class = shift;
return bless {
rules => {},
zones => {},
links => {},
}, $class;
}
sub parse_file {
my $self = shift;
my $file = shift;
open my $fh, '<', $file
or die "Cannot read $file: $!";
while (<$fh>) {
chomp;
$self->_parse_line($_);
}
close $fh or die $!;
}
sub _parse_line {
my $self = shift;
my $line = shift;
return if $line =~ /^\s+$/;
return if $line =~ /^#/;
# remove any comments at the end of the line
$line =~ s/\s*#.+$//;
if ( $self->{in_zone} && $line =~ /^[ \t]/ ) {
$self->_parse_zone( $line, $self->{in_zone} );
return;
}
foreach (qw( Rule Zone Link )) {
if ( substr( $line, 0, 4 ) eq $_ ) {
my $m = '_parse_' . lc $_;
$self->$m($line);
}
}
}
## no critic (Subroutines::ProhibitUnusedPrivateSubroutines)
sub _parse_rule {
my $self = shift;
my $rule = shift;
my @items = split /\s+/, $rule, 10;
shift @items;
my $name = shift @items;
my %rule;
@rule{qw( from to type in on at save letter )} = @items;
delete $rule{letter} if $rule{letter} eq '-';
# As of the 2003a data, there are no rules with a type set
delete $rule{type} if $rule{type} eq '-';
push @{ $self->{rules}{$name} },
DateTime::TimeZone::OlsonDB::Rule->new( name => $name, %rule );
undef $self->{in_zone};
}
sub _parse_zone {
my $self = shift;
my $zone = shift;
my $name = shift;
my $expect = $name ? 5 : 6;
my @items = grep { defined && length } split /\s+/, $zone, $expect;
my %obs;
unless ($name) {
shift @items; # remove "Zone"
$name = shift @items;
}
@obs{qw( gmtoff rules format until )} = @items;
if ( $obs{rules} =~ /\d\d?:\d\d/ ) {
$obs{offset_from_std} = delete $obs{rules};
}
else {
delete $obs{rules} if $obs{rules} eq '-';
}
delete $obs{until} unless defined $obs{until};
push @{ $self->{zones}{$name} }, \%obs;
$self->{in_zone} = $name;
}
sub _parse_link {
my $self = shift;
my $link = shift;
my @items = split /\s+/, $link, 3;
$self->{links}{ $items[2] } = $items[1];
undef $self->{in_zone};
}
## use critic
sub links { %{ $_[0]->{links} } }
sub zone_names { keys %{ $_[0]->{zones} } }
sub zone {
my $self = shift;
my $name = shift;
die "Invalid zone name $name"
unless exists $self->{zones}{$name};
return DateTime::TimeZone::OlsonDB::Zone->new(
name => $name,
observances => $self->{zones}{$name},
olson_db => $self,
);
}
sub expanded_zone {
my $self = shift;
my %p = @_;
$p{expand_to_year} ||= (localtime)[5] + 1910;
my $zone = $self->zone( $p{name} );
$zone->expand_observances( $self, $p{expand_to_year} );
return $zone;
}
sub rules_by_name {
my $self = shift;
my $name = shift;
return unless defined $name;
die "Invalid rule name $name"
unless exists $self->{rules}{$name};
return @{ $self->{rules}{$name} };
}
sub parse_day_spec {
my ( $day, $month, $year ) = @_;
return ( $month, $day ) if $day =~ /^\d+$/;
if ( $day =~ /^last(\w\w\w)$/ ) {
my $dow = $DAYS{$1};
my $last_day = DateTime->last_day_of_month(
year => $year,
month => $month,
time_zone => 'floating',
);
my $dt = DateTime->new(
year => $year,
month => $month,
day => $last_day->day,
time_zone => 'floating',
);
while ( $dt->day_of_week != $dow ) {
$dt -= $PLUS_ONE_DAY_DUR;
}
return ( $dt->month, $dt->day );
}
elsif ( $day =~ /^(\w\w\w)([><])=(\d\d?)$/ ) {
my $dow = $DAYS{$1};
my $dt = DateTime->new(
year => $year,
month => $month,
day => $3,
time_zone => 'floating',
);
my $dur = $2 eq '<' ? $MINUS_ONE_DAY_DUR : $PLUS_ONE_DAY_DUR;
while ( $dt->day_of_week != $dow ) {
$dt += $dur;
}
return ( $dt->month, $dt->day );
}
else {
die "Invalid on spec for rule: $day\n";
}
}
sub utc_datetime_for_time_spec {
my %p = @_;
# 'w'all - ignore it, because that's the default
$p{spec} =~ s/w$//;
# 'g'reenwich, 'u'tc, or 'z'ulu
my $is_utc = $p{spec} =~ s/[guz]$//;
# 's'tandard time - ignore DS offset
my $is_std = $p{spec} =~ s/s$//;
## no critic (NamingConventions::ProhibitAmbiguousNames)
my ( $hour, $minute, $second ) = split /:/, $p{spec};
$minute = 0 unless defined $minute;
$second = 0 unless defined $second;
my $add_day = 0;
if ( $hour >= 24 ) {
$hour = $hour - 24;
$add_day = 1;
}
my $utc;
if ($is_utc) {
$utc = DateTime->new(
year => $p{year},
month => $p{month},
day => $p{day},
hour => $hour,
minute => $minute,
second => $second,
time_zone => 'floating',
);
}
else {
my $local = DateTime->new(
year => $p{year},
month => $p{month},
day => $p{day},
hour => $hour,
minute => $minute,
second => $second,
time_zone => 'floating',
);
$p{offset_from_std} = 0 if $is_std;
my $dur = DateTime::Duration->new(
seconds => $p{offset_from_utc} + $p{offset_from_std} );
$utc = $local - $dur;
}
$utc->add( days => 1 ) if $add_day;
return $utc;
}
1;
# ABSTRACT: An object to represent an Olson time zone database
__END__
=pod
=encoding UTF-8
=head1 NAME
DateTime::TimeZone::OlsonDB - An object to represent an Olson time zone database
=head1 VERSION
version 2.62
=head1 SYNOPSIS
none yet
=head1 DESCRIPTION
This module parses the Olson database time zone definition files and creates
various objects representing time zone data.
Each time zone is broken down into several parts. The first piece is an
observance, which is an offset from UTC and an abbreviation. A single zone may
contain many observances, reflecting historical changes in that time zone over
time. An observance may also refer to a set of rules.
Rules are named, and may apply to many different zones. For example, the "US"
rules apply to most of the time zones in the US, unsurprisingly. Rules are
made of an offset from standard time and a definition of when that offset
changes. Changes can be a one time thing, or they can recur at regular times
through a span of years.
Each rule may have an associated letter, which is used to generate an
abbreviated name for the time zone, along with the offset's abbreviation. For
example, if the offset's abbreviation is "C%sT", and the a rule specifies the
letter "S", then the abbreviation when that rule is in effect is "CST".
=head1 USAGE
Not yet documented. This stuff is a mess.
=head1 SUPPORT
Bugs may be submitted at L<https://github.com/houseabsolute/DateTime-TimeZone/issues>.
=head1 SOURCE
The source code repository for DateTime-TimeZone can be found at L<https://github.com/houseabsolute/DateTime-TimeZone>.
=head1 AUTHOR
Dave Rolsky <autarch@urth.org>
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2024 by Dave Rolsky.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
The full text of the license can be found in the
F<LICENSE> file included with this distribution.
=cut