Koha/C4/Scheduler.pm

164 lines
3.9 KiB
Perl

package C4::Scheduler;
# Copyright 2007 Liblime Ltd
#
# This file is part of Koha.
#
# Koha is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# Koha is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with Koha; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
use strict;
#use warnings; FIXME - Bug 2505
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
use C4::Context;
use Schedule::At;
BEGIN {
# set the version for version checking
$VERSION = 0.02;
require Exporter;
@ISA = qw(Exporter);
@EXPORT =
qw(get_jobs get_at_jobs get_at_job add_at_job remove_at_job);
}
=head1 NAME
C4::Scheduler - Module for running jobs with the unix at command
=head1 SYNOPSIS
use C4::Scheduler;
=head1 DESCRIPTION
=head1 METHODS
=over 2
=cut
=item get_jobs();
This will return all scheduled jobs
=cut
sub get_jobs {
my $jobs = get_at_jobs();
# add call to get cron jobs here too
return ($jobs);
}
=item get_at_jobs();
This will return all At scheduled jobs
=cut
sub get_at_jobs {
my %jobs = Schedule::At::getJobs();
return (\%jobs);
}
=item get_at_job($id)
This will return the At job with the given id
=cut
sub get_at_job {
my ($id)=@_;
my %jobs = Schedule::At::getJobs(JOBID => $id);
}
=item add_at_job ($time,$command)
Given a timestamp and a command this will schedule the job to run at that time.
Returns true if the job is added to the queue and false otherwise.
=cut
sub add_at_job {
my ($time,$command) = @_;
# FIXME - a description of the task to be run
# may be a better tag, since the tag is displayed
# in the job list that the administrator sees - e.g.,
# "run report foo, send to foo@bar.com"
Schedule::At::add(TIME => $time, COMMAND => $command, TAG => $command);
# FIXME - this method of checking whether the job was added
# to the queue is less than perfect:
#
# 1. Since the command is the tag, it is possible that there is
# already a job in the queue with the same tag. However, since
# the tag is what displays in the job list, we can't just
# give it a unique ID.
# 2. Schedule::At::add() is supposed to return a non-zero
# value if it fails to add a job - however, it does
# not check all error conditions - in particular, it does
# not check the return value of the "at" run; it basically
# complains only if it can't find at.
# 3. Similary, Schedule::At::add() does not do something more useful,
# such as returning the job ID. To be fair, it is possible
# that 'at' does not allow this in any portable way.
# 4. Although unlikely, it is possible that a job could be added
# and completed instantly, thus dropping off the queue.
my $job_found = 0;
eval {
my %jobs = Schedule::At::getJobs(TAG => $command);
$job_found = scalar(keys %jobs) > 0;
};
if ($@) {
return 0;
} else {
return $job_found;
}
}
sub remove_at_job {
my ($jobid)=@_;
Schedule::At::remove(JOBID => $jobid);
}
1;
__END__
=back
=head1 BUGS
At some point C<C4::Scheduler> should be refactored:
=over 4
=item At and C<Schedule::At> does not work on Win32.
=item At is not installed by default on all platforms.
=item The At queue used by Koha is owned by the httpd user. If multiple
Koha databases share an Apache instance on a server, everybody can
see everybody's jobs.
=item There is no support for scheduling a job to run more than once.
=back
=head1 AUTHOR
Chris Cormack <crc@liblime.com>
=cut