# $Id$
#
+use strict;
+
package Julian;
-use FileHandle;
-use DXDebug;
-use Carp;
-use strict;
+use vars qw(@days @ldays @month);
+@days = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
+@ldays = (31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
+@month = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
-my @days = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
+sub alloc($$$)
+{
+ my ($pkg, $year, $thing) = @_;
+ return bless [$year, $thing], ref($pkg)||$pkg;
+}
-# take a unix date and transform it into a julian day (ie (1998, 13) = 13th day of 1998)
-sub unixtoj
+sub copy
{
- my ($t) = @_;
- my ($day, $mon, $year) = (gmtime($t))[3..5];
- my $jday;
-
- # set the correct no of days for february
- if ($year < 100) {
- $year += ($year < 50) ? 2000 : 1900;
- }
- $days[1] = isleap($year) ? 29 : 28;
- for (my $i = 0, $jday = 0; $i < $mon; $i++) {
- $jday += $days[$i];
- }
- $jday += $day;
- return ($year, $jday);
+ my $old = shift;
+ return $old->alloc(@$old);
}
-# take a julian date and subtract a number of days from it, returning the julian date
-sub sub
+sub cmp($$)
{
- my ($year, $day, $amount) = @_;
- my $diny = isleap($year) ? 366 : 365;
- $day -= $amount;
- while ($day <= 0) {
- $day += $diny;
- $year -= 1;
- $diny = isleap($year) ? 366 : 365;
- }
- return ($year, $day);
+ my ($a, $b) = @_;
+ return $a->[1] - $b->[1] if ($a->[0] == $b->[0]);
+ return $a->[0] - $b->[0];
}
-sub add
+sub year
{
- my ($year, $day, $amount) = @_;
- my $diny = isleap($year) ? 366 : 365;
- $day += $amount;
- while ($day > $diny) {
- $day -= $diny;
- $year += 1;
- $diny = isleap($year) ? 366 : 365;
- }
- return ($year, $day);
-}
+ return $_[0]->[0];
+}
-sub cmp
+sub thing
{
- my ($y1, $d1, $y2, $d2) = @_;
- return $d1 - $d2 if ($y1 == $y2);
- return $y1 - $y2;
+ return $_[0]->[1];
}
+package Julian::Day;
+
+use vars qw(@ISA);
+@ISA = qw(Julian);
+
# is it a leap year?
-sub isleap
+sub _isleap
{
- my $year = shift;
- return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0;
+ my $year = shift;
+ return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0;
}
-# this section deals with files that are julian date based
+sub new($$)
+{
+ my $pkg = shift;
+ my $t = shift;
+ my ($year, $day) = (gmtime($t))[5,7];
+ $year += 1900;
+ return $pkg->SUPER::alloc($year, $day+1);
+}
-# open a data file with prefix $fn/$year/$day.dat and return an object to it
-sub open
+# take a julian date and subtract a number of days from it, returning the julian date
+sub sub($$)
{
- my ($pkg, $fn, $year, $day, $mode) = @_;
-
- # if we are writing, check that the directory exists
- if (defined $mode) {
- my $dir = "$fn/$year";
- mkdir($dir, 0777) if ! -e $dir;
- }
- my $self = {};
- $self->{fn} = sprintf "$fn/$year/%03d.dat", $day;
- $mode = 'r' if !$mode;
- my $fh = new FileHandle $self->{fn}, $mode;
- return undef if !$fh;
- $fh->autoflush(1) if $mode ne 'r'; # make it autoflushing if writable
- $self->{fh} = $fh;
- $self->{year} = $year;
- $self->{day} = $day;
- dbg("julian", "opening $self->{fn}\n");
-
- return bless $self, $pkg;
+ my ($old, $amount) = @_;
+ my $self = $old->copy;
+ my $diny = _isleap($self->[0]) ? 366 : 365;
+ $self->[1] -= $amount;
+ while ($self->[1] <= 0) {
+ $self->[0] -= 1;
+ $diny = _isleap($self->[0]) ? 366 : 365;
+ $self->[1] += $diny;
+ }
+ return $self;
}
-# close the data file
-sub close
+sub add($$)
{
- my $self = shift;
- undef $self->{fh}; # close the filehandle
- delete $self->{fh};
+ my ($old, $amount) = @_;
+ my $self = $old->copy;
+ my $diny = _isleap($self->[0]) ? 366 : 365;
+ $self->[1] += $amount;
+ while ($self->[1] > $diny) {
+ $self->[1] -= $diny;
+ $self->[0] += 1;
+ $diny = _isleap($self->[0]) ? 366 : 365;
+ }
+ return $self;
+}
+
+sub as_string
+{
+ my $self = shift;
+ my $days = $self->[1];
+ my $mon = 0;
+ for (_isleap($self->[0]) ? @Julian::ldays : @Julian::days) {
+ if ($_ < $days) {
+ $days -= $_;
+ $mon++;
+ } else {
+ last;
+ }
+ }
+ return "$days-$Julian::month[$mon]-$self->[0]";
+}
+
+package Julian::Month;
+
+use vars qw(@ISA);
+@ISA = qw(Julian);
+
+sub new($$)
+{
+ my $pkg = shift;
+ my $t = shift;
+ my ($mon, $year) = (gmtime($t))[4,5];
+ $year += 1900;
+ return $pkg->SUPER::alloc($year, $mon+1);
+}
+
+# take a julian month and subtract a number of months from it, returning the julian month
+sub sub($$)
+{
+ my ($old, $amount) = @_;
+ my $self = $old->copy;
+
+ $self->[1] -= $amount;
+ while ($self->[1] <= 0) {
+ $self->[1] += 12;
+ $self->[0] -= 1;
+ }
+ return $self;
}
-sub DESTROY # catch undefs and do what is required further do the tree
+sub add($$)
{
- my $self = shift;
- dbg("julian", "closing $self->{fn}\n");
- undef $self->{fh} if defined $self->{fh};
+ my ($old, $amount) = @_;
+ my $self = $old->copy;
+
+ $self->[1] += $amount;
+ while ($self->[1] > 12) {
+ $self->[1] -= 12;
+ $self->[0] += 1;
+ }
+ return $self;
}
+sub as_string
+{
+ my $self = shift;
+ return "$Julian::month[$self->[1]]-$self->[0]";
+}
+
+
1;
projects / spider.git / blobdiff