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# This code is part of Perl distribution Mail-Box version 4.01.
# The POD got stripped from this file by OODoc version 3.05.
# For contributors see file ChangeLog.
# This software is copyright (c) 2001-2025 by Mark Overmeer.
# This is free software; you can redistribute it and/or modify it under
# the same terms as the Perl 5 programming language system itself.
# SPDX-License-Identifier: Artistic-1.0-Perl OR GPL-1.0-or-later
package Mail::Box::Locker;{
our $VERSION = '4.01';
}
use parent 'Mail::Reporter';
use strict;
use warnings;
use Log::Report 'mail-box', import => [ qw/__x error panic/ ];
use Scalar::Util qw/weaken/;
use Devel::GlobalDestruction qw/in_global_destruction/;
#--------------------
my %lockers = (
DOTLOCK => __PACKAGE__ .'::DotLock',
FCNTLLOCK => __PACKAGE__ .'::FcntlLock',
FLOCK => __PACKAGE__ .'::Flock',
MULTI => __PACKAGE__ .'::Multi',
MUTT => __PACKAGE__ .'::Mutt',
NFS => __PACKAGE__ .'::NFS',
NONE => __PACKAGE__,
POSIX => __PACKAGE__ .'::POSIX',
);
sub new(@)
{ my ($class, %args) = @_;
$class eq __PACKAGE__ or return $class->SUPER::new(%args);
# Try to figure out which locking method we really want (bootstrap)
my $method
= ! defined $args{method} ? 'DOTLOCK'
: ref $args{method} eq 'ARRAY' ? 'MULTI'
: uc $args{method};
my $create = $lockers{$method} || $args{$method}
or error __x"no locking method {name} defined: use {avail}.", name => $method, avail => [ keys %lockers ];
# compile the locking module (if needed)
eval "require $create";
error __x"failed to use locking module {class}:\n{error}", class => $create, error => $@ if $@;
$args{use} = $args{method} if ref $args{method} eq 'ARRAY';
$create->SUPER::new(%args);
}
sub init($)
{ my ($self, $args) = @_;
$self->SUPER::init($args);
$self->{MBL_expires} = $args->{expires} || 3600; # one hour
$self->{MBL_timeout} = $args->{timeout} || 10; # ten secs
$self->{MBL_filename} = $args->{file} || $args->{folder}->name;
$self->{MBL_has_lock} = 0;
$self->folder($args->{folder});
$self;
}
#--------------------
sub timeout(;$) { my $self = shift; @_ ? $self->{MBL_timeout} = shift : $self->{MBL_timeout} }
sub expires(;$) { my $self = shift; @_ ? $self->{MBL_expires} = shift : $self->{MBL_expires} }
sub name { $_[0]->notImplemented }
sub lockMethod($$$$) { panic "Method removed: use inheritance to implement own method." }
sub folder(;$)
{ my $self = shift;
@_ && $_[0] or return $self->{MBL_folder};
$self->{MBL_folder} = shift;
weaken $self->{MBL_folder};
}
sub filename(;$) { my $self = shift; @_ ? $self->{MBL_filename} = shift : $self->{MBL_filename} }
#--------------------
sub lock($) { $_[0]->{MBL_has_lock} = 1 }
sub isLocked($) {0}
sub hasLock() { $_[0]->{MBL_has_lock} }
# implementation hazard: the unlock must be self-reliant, without
# help by the folder, because it may be called at global destruction
# after the folder has been removed.
sub unlock() { $_[0]->{MBL_has_lock} = 0 }
#--------------------
sub DESTROY()
{ my $self = shift;
return $self if in_global_destruction;
$self->unlock if $self->hasLock;
$self->SUPER::DESTROY;
$self;
}
1;
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