1 files changed, 138 insertions, 0 deletions
diff --git a/contrib/perl5/lib/Time/Local.pm b/contrib/perl5/lib/Time/Local.pm
new file mode 100644
index 0000000..eef412d
--- /dev/null
+++ b/contrib/perl5/lib/Time/Local.pm
@@ -0,0 +1,138 @@
+package Time::Local;
+require 5.000;
+require Exporter;
+use Carp;
+
+@ISA = qw(Exporter);
+@EXPORT = qw(timegm timelocal);
+
+=head1 NAME
+
+Time::Local - efficiently compute time from local and GMT time
+
+=head1 SYNOPSIS
+
+    $time = timelocal($sec,$min,$hours,$mday,$mon,$year);
+    $time = timegm($sec,$min,$hours,$mday,$mon,$year);
+
+=head1 DESCRIPTION
+
+These routines are quite efficient and yet are always guaranteed to agree
+with localtime() and gmtime().  We manage this by caching the start times
+of any months we've seen before.  If we know the start time of the month,
+we can always calculate any time within the month.  The start times
+themselves are guessed by successive approximation starting at the
+current time, since most dates seen in practice are close to the
+current date.  Unlike algorithms that do a binary search (calling gmtime
+once for each bit of the time value, resulting in 32 calls), this algorithm
+calls it at most 6 times, and usually only once or twice.  If you hit
+the month cache, of course, it doesn't call it at all.
+
+timelocal is implemented using the same cache.  We just assume that we're
+translating a GMT time, and then fudge it when we're done for the timezone
+and daylight savings arguments.  The timezone is determined by examining
+the result of localtime(0) when the package is initialized.  The daylight
+savings offset is currently assumed to be one hour.
+
+Both routines return -1 if the integer limit is hit. I.e. for dates
+after the 1st of January, 2038 on most machines.
+
+=cut
+
+BEGIN {
+    $SEC  = 1;
+    $MIN  = 60 * $SEC;
+    $HR   = 60 * $MIN;
+    $DAY  = 24 * $HR;
+    $epoch = (localtime(2*$DAY))[5];	# Allow for bugs near localtime == 0.
+
+    $YearFix = ((gmtime(946684800))[5] == 100) ? 100 : 0;
+
+}
+
+sub timegm {
+    $ym = pack(C2, @_[5,4]);
+    $cheat = $cheat{$ym} || &cheat;
+    return -1 if $cheat<0 and $^O ne 'VMS';
+    $cheat + $_[0] * $SEC + $_[1] * $MIN + $_[2] * $HR + ($_[3]-1) * $DAY;
+}
+
+sub timelocal {
+    my $t = &timegm;
+    my $tt = $t;
+
+    my (@lt) = localtime($t);
+    my (@gt) = gmtime($t);
+    if ($t < $DAY and ($lt[5] >= 70 or $gt[5] >= 70 )) {
+      # Wrap error, too early a date
+      # Try a safer date
+      $tt = $DAY;
+      @lt = localtime($tt);
+      @gt = gmtime($tt);
+    }
+
+    my $tzsec = ($gt[1] - $lt[1]) * $MIN + ($gt[2] - $lt[2]) * $HR;
+
+    my($lday,$gday) = ($lt[7],$gt[7]);
+    if($lt[5] > $gt[5]) {
+	$tzsec -= $DAY;
+    }
+    elsif($gt[5] > $lt[5]) {
+	$tzsec += $DAY;
+    }
+    else {
+	$tzsec += ($gt[7] - $lt[7]) * $DAY;
+    }
+
+    $tzsec += $HR if($lt[8]);
+    
+    $time = $t + $tzsec;
+    return -1 if $cheat<0 and $^O ne 'VMS';
+    @test = localtime($time + ($tt - $t));
+    $time -= $HR if $test[2] != $_[2];
+    $time;
+}
+
+sub cheat {
+    $year = $_[5];
+    $year -= 1900
+    	if $year > 1900;
+    $month = $_[4];
+    croak "Month '$month' out of range 0..11"	if $month > 11 || $month < 0;
+    croak "Day '$_[3]' out of range 1..31"	if $_[3] > 31 || $_[3] < 1;
+    croak "Hour '$_[2]' out of range 0..23"	if $_[2] > 23 || $_[2] < 0;
+    croak "Minute '$_[1]' out of range 0..59"	if $_[1] > 59 || $_[1] < 0;
+    croak "Second '$_[0]' out of range 0..59"	if $_[0] > 59 || $_[0] < 0;
+    $guess = $^T;
+    @g = gmtime($guess);
+    $year += $YearFix if $year < $epoch;
+    $lastguess = "";
+    $counter = 0;
+    while ($diff = $year - $g[5]) {
+	croak "Can't handle date (".join(", ",@_).")" if ++$counter > 255;
+	$guess += $diff * (363 * $DAY);
+	@g = gmtime($guess);
+	if (($thisguess = "@g") eq $lastguess){
+	    return -1; #date beyond this machine's integer limit
+	}
+	$lastguess = $thisguess;
+    }
+    while ($diff = $month - $g[4]) {
+	croak "Can't handle date (".join(", ",@_).")" if ++$counter > 255;
+	$guess += $diff * (27 * $DAY);
+	@g = gmtime($guess);
+	if (($thisguess = "@g") eq $lastguess){
+	    return -1; #date beyond this machine's integer limit
+	}
+	$lastguess = $thisguess;
+    }
+    @gfake = gmtime($guess-1); #still being sceptic
+    if ("@gfake" eq $lastguess){
+	return -1; #date beyond this machine's integer limit
+    }
+    $g[3]--;
+    $guess -= $g[0] * $SEC + $g[1] * $MIN + $g[2] * $HR + $g[3] * $DAY;
+    $cheat{$ym} = $guess;
+}
+
+1;