######################################################################
# YukiWikiDB.pm - This is PyukiWiki, yet another Wiki clone.
# $Id: YukiWikiDB.pm,v 1.95 2011/12/21 05:00:58 papu Exp $
#
# "Yuki::YukiWikiDB" version 2.1.2a $$
# Author: Hiroshi Yuki
# http://www.hyuki.com/
# Copyright (C) 2004-2011 by Nekyo.
# http://nekyo.qp.land.to/
# Copyright (C) 2005-2011 PyukiWiki Developers Team
# http://pyukiwiki.sfjp.jp/
# Based on YukiWiki http://www.hyuki.com/yukiwiki/
# Powerd by PukiWiki http://pukiwiki.sfjp.jp/
# License: GPL2 and/or Artistic or each later version
#
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
# Return:LF Code=UTF-8 1TAB=4Spaces
######################################################################

package Yuki::YukiWikiDB;
$VERSION="2.1.2a";

use strict;
use Fcntl ':flock';

# Constructor
sub new {
	return shift->TIEHASH(@_);
}

# tying
sub TIEHASH {
	my ($class, $dbname) = @_;
	my $self = {
		dir => $dbname,
		keys => [],
	};
	if (not -d $self->{dir}) {
		if (!mkdir($self->{dir}, 0777)) {
			die "mkdir(" . $self->{dir} . ") fail";
		}
	}
	return bless($self, $class);
}

# Store
sub STORE {
	my ($self, $key, $value) = @_;
	my $filename = &make_filename($self, $key);
	&lock_store($filename, $value);
	return $value;
}

# Fetch
sub FETCH {
	my ($self, $key) = @_;
	my $filename = &make_filename($self, $key);
	my $value = &lock_fetch($filename);
	return $value;
}

# Exists
sub EXISTS {
	my ($self, $key) = @_;
	my $filename = &make_filename($self, $key);
	return -e($filename);
}

# Delete
sub DELETE {
	my ($self, $key) = @_;
	my $filename = &make_filename($self, $key);
	unlink $filename;
	# return delete $self->{$key};
}

sub FIRSTKEY {
	my ($self) = @_;
	opendir(DIR, $self->{dir}) or die $self->{dir};
	@{$self->{keys}} = grep /\.txt$/, readdir(DIR);
	foreach my $name (@{$self->{keys}}) {
		$name =~ s/\.txt$//;
		$name =~ s/[0-9A-F][0-9A-F]/pack("C", hex($&))/eg;
	}
	return shift @{$self->{keys}};
}

sub NEXTKEY {
	my ($self) = @_;
	return shift @{$self->{keys}};
}

sub make_filename {
	my ($self, $key) = @_;
	my $enkey = '';
	foreach my $ch (split(//, $key)) {
		$enkey .= sprintf("%02X", ord($ch));
	}
	return $self->{dir} . "/$enkey.txt";
}

sub lock_store {
	my ($filename, $value) = @_;
	open(FILE, "+< $filename") or open(FILE, "> $filename") or die "$filename cannot be created";
	eval("flock(FILE, LOCK_EX)");
	if ($@) {
		# Your platform does not support flock.
		# Implement another EXCLUSIVE LOCK here.
	}
	truncate(FILE, 0);
	# binmode(FILE);
	$value =~ s/\x0D\x0A/\n/g;
	print FILE $value;
	eval("flock(FILE, LOCK_UN)");
	if ($@) {
		# Your platform does not support flock.
		# Implement another UNLOCK here.
	}
	close(FILE);
}

sub lock_fetch {
	my ($filename) = @_;
	open(FILE, "$filename") or return(undef);
	eval("flock(FILE, LOCK_SH)");
	if ($@) {
		# Your platform does not support flock.
		# Implement another SHARED LOCK here.
	}
	local $/;
	my $value = <FILE>;
	eval("flock(FILE, LOCK_UN)");
	if ($@) {
		# Your platform does not support flock.
		# Implement another UNLOCK here.
	}
	close(FILE);
	return $value;
}

1;
