#!/usr/bin/perl
# TmNetWiki version 0.4 (September 11, 2002)
# Copyright (C) 2002 Adam Brate
#   <ab@adambrate.com> 
# Based on the GPLed UseModWiki 0.92
# Copyright (C) 2000-2001 Clifford A. Adams
#    <caadams@frontiernet.net> or <usemod@usemod.com>
# Based on the GPLed AtisWiki 0.3  (C) 1998 Markus Denker
#    <marcus@ira.uka.de>
# ...which was based on
#    the LGPLed CVWiki CVS-patches (C) 1997 Peter Merel
#    and The Original WikiWikiWeb  (C) Ward Cunningham
#        <ward@c2.com> (code reused with permission)
# Email and ThinLine options by Jim Mahoney <mahoney@marlboro.edu>
#
# This program 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.
#
# This program 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 this program; if not, write to the
#    Free Software Foundation, Inc.
#    59 Temple Place, Suite 330
#    Boston, MA 02111-1307 USA


package Wiki::lock;
use strict;
# needs subs   Wiki::file: CreateDir,
#              Wiki::translate: Ts
# needs consts LockDir
use base 'Exporter';
use Wiki::consts;
use Wiki::file;
use Wiki::translate;
#if ($^V and $^V gt v5.6.0) {
#    our @EXPORT;
#else {
    use vars qw(@EXPORT);
#}
@EXPORT = qw(
  RequestLockDir
  ReleaseLockDir
  RequestLock
  ReleaseLock
  ForceReleaseLock
);

sub RequestLockDir {
  my ($name, $tries, $wait, $errorDie) = @_;
  my ($lockName, $n);

  &CreateDir($TempDir);
  $lockName = $LockDir . $name;
  $n = 0;
  while (mkdir($lockName, 0555) == 0) {
    if ($! != 17) {
      die(Ts('can not make %s', $LockDir) . ": $!\n")  if $errorDie;
      return 0;
    }
    return 0  if ($n++ >= $tries); 
    sleep($wait);
  }
  return 1;
}

sub ReleaseLockDir {
  my ($name) = @_;
  rmdir($LockDir . $name);
}

sub RequestLock {
  # 10 tries, 3 second wait, die on error
  return &RequestLockDir("main", 10, 3, 1);
}

sub ReleaseLock {
  &ReleaseLockDir('main');
}

sub ForceReleaseLock {
  my ($name) = @_;
  my $forced;

  # First try to obtain lock (in case of normal edit lock)
  # 5 tries, 3 second wait, do not die on error
  $forced = !&RequestLockDir($name, 5, 3, 0);
  &ReleaseLockDir($name);  # Release the lock, even if we didn't get it.
  return $forced;
}