# $RedRiver: Cached.pm,v 1.11 2005/05/21 00:05:13 andrew Exp $
use strict;
package BT::MetaInfo::Cached;
require 5.6.0;
use vars qw( $VERSION @ISA );
use Cache::FileCache;
use File::Basename;
use Digest::MD5;
use BT::MetaInfo;
use base 'BT::MetaInfo';
$VERSION = do { my @r = (q$Id: Cached.pm,v 1.12 2006/05/15 18:47:04 andrew Exp $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
sub new
{
my $class = shift;
my $file = shift;
my $cache_settings = shift;
if (ref $file eq 'HASH') {
$cache_settings = $file;
$file = undef;
}
$cache_settings->{namespace} ||= 'BT::MetaInfo::Cached';
$cache_settings->{default_expires_in} ||= 7 * 24 * 60 * 60;
$cache_settings->{auto_purge_interval} ||= 1 * 1 * 10 * 60;
my $cache = new Cache::FileCache( $cache_settings );
my $obj = (defined($file)) ? _load($file, $cache) : {};
bless($obj, $class);
$obj->{cache} = $cache;
return $obj;
}
sub _load {
my $file = shift;
my $cache = shift;
my $basename = basename($file);
my $info = $cache->get( $basename );
my $md5;
if (defined $info && $info->{'md5'}) {
my $old_md5 = delete $info->{'md5'};
my $cur_md5 = _MD5_file($file);
if ($old_md5 ne $cur_md5) {
$cache->remove( $basename );
$info = undef;
}
$md5 = $cur_md5;
}
unless (defined $info) {
$info = BT::MetaInfo::_load($file);
$info->{'md5'} = $md5;
$cache->set( $basename, $info );
delete $info->{'md5'};
}
return $info;
}
sub save
{
my $self = shift;
my $file = shift;
my $basename = basename($file);
my $cache = delete $self->{'cache'};
if ( $self->SUPER::save($file, @_) ) {
my %info_hash = %$self; # unbless
$info_hash{'md5'} = _MD5_file($file);
$cache->set($basename, \%info_hash)
}
$self->{'cache'} = $cache;
return 1;
}
sub _MD5_file
{
my $file = shift;
my $ctx = Digest::MD5->new;
open my $fh, $file or die "Couldn't open FILE '$file': $!";
binmode $fh;
$ctx->addfile($fh);
close $fh;
return $ctx->hexdigest;
}