/usr/share/perl5/Arch/SharedCache.pm is in libarch-perl 0.5.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | # Arch Perl library, Copyright (C) 2004 Mikhael Goikhman
#
# 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
use 5.005;
use strict;
package Arch::SharedCache;
use base 'Arch::SharedIndex';
use Arch::Util qw(save_file load_file);
sub new ($%) {
my $class = shift;
my %init = @_;
my $dir = $init{dir} or die "No cache directory given\n";
unless (-d $dir) {
mkdir($dir, 0777) or die "Can't create cache directory $dir: $!\n";
}
-d $dir or die "No cache directory ($dir)\n";
my $index_file = $init{index_file} || $init{file} || '.index';
$index_file = "$dir/$index_file" unless $index_file =~ m!^\.?/!;
my $self = $class->SUPER::new(
# default to a more readable serialization output
perl_data_indent => 1,
perl_data_pair => " => ",
%init,
file => $index_file,
);
$self->{dir} = $dir;
$self->{generic_filenames} = $init{generic_filenames} || 0;
return $self;
}
sub generate_unique_token ($) {
my $self = shift;
my $dir = $self->{dir};
my $prefix = time() . "-";
my $token = $prefix . "000000";
return $token unless -e "$dir/$token";
my $tries = 1000000;
do {
$token = $prefix . sprintf("%06d", rand(1000000));
} while -e "$dir/$token" && --$tries;
die "Failed to acquire unused file name $dir/$prefix*\n" unless $tries;
return $token;
}
sub file_name_by_token ($$) {
my $self = shift;
my $token = shift;
$token =~ s!/!%!g;
return "$self->{dir}/$token";
}
sub delete_value ($$$) {
my $self = shift;
my ($key, $token) = @_;
$token = $key if $token eq "";
my $file_name = $self->file_name_by_token($token);
return unless -e $file_name;
unlink($file_name) or warn "Can't unlink $file_name: $!\n";
}
sub fetch_value ($$$) {
my $self = shift;
my ($key, $token) = @_;
$token = $key if $token eq "";
my $file_name = $self->file_name_by_token($token);
my $value = eval { load_file($file_name); };
warn $@ if $@;
$self->decode_value(\$value);
return $value;
}
sub store_value ($$$) {
my $self = shift;
my ($key, $token, $value) = @_;
$token = $key
if defined $token && $token eq "";
$token = $key
if !defined $token && !$self->{generic_filenames};
$token = $self->generate_unique_token
if !defined $token || $token eq "";
my $file_name = $self->file_name_by_token($token);
$self->encode_value(\$value);
eval { save_file($file_name, \$value); };
warn $@ if $@;
$token = "" if $key eq $token;
$token = undef if $@;
return $token;
}
1;
__END__
=head1 NAME
Arch::SharedCache - a synchronized data structure (map) for IPC
=head1 SYNOPSIS
use Arch::SharedCache;
my $cache = Arch::SharedCache->new(
dir => '/tmp/dir-listings',
max_size => 100,
expiration => 600, # 10 minutes
);
sub ls_long { scalar `ls -l $_[0]` }
my $user_dir = '/usr/share';
$cache->store($user_dir => ls_long($user_dir));
$cache->fetch_store(sub { ls_long($_[0]) }, qw(/tmp /bin /usr/share));
printf "Cached listing of $user_dir:\n%s", $cache->fetch($user_dir);
$cache->delete($user_dir);
# examine /tmp/dir-listings/ after running this script
# see also synopsys of Arch::SharedIndex
=head1 DESCRIPTION
Arch::SharedCache provides an Arch::SharedIndex implementation using a
single file per value.
=head1 METHODS
The following methods are available:
B<new>.
Other methods are documented in L<Arch::SharedIndex>.
=over 4
=item B<new> I<options>
Create a new Arch::SharedCache object. I<options> is a hash of options.
=over 4
=item B<dir>
The cache directory used to store data. Will be created if it doesn't exist.
=item B<index_file>
Name of the index file for the cache. Defaults to C<B<dir>/.index>.
=back
=back
=head1 BUGS
Awaiting for your reports.
=head1 AUTHORS
Mikhael Goikhman (migo@homemail.com--Perl-GPL/arch-perl--devel).
Enno Cramer (uebergeek@web.de--2003/arch-perl--devel).
=head1 SEE ALSO
For more information, see L<Arch::SharedIndex>.
=cut
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