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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.
package Bugzilla::Bloomfilter;
use 5.10.1;
use strict;
use warnings;
use Bugzilla::Constants;
use Algorithm::BloomFilter;
use File::Temp qw(tempfile);
sub _new_bloom_filter {
my ($n) = @_;
my $p = 0.01;
my $m = $n * abs(log $p) / log(2) ** 2;
my $k = $m / $n * log(2);
return Algorithm::BloomFilter->new($m, $k);
}
sub _filename {
my ($name) = @_;
my $datadir = bz_locations->{datadir};
return sprintf("%s/%s.bloom", $datadir, $name);
}
sub populate {
my ($class, $name, $items) = @_;
my $memcached = Bugzilla->memcached;
my $filter = _new_bloom_filter(@$items + 0);
foreach my $item (@$items) {
$filter->add($item);
}
my ($fh, $filename) = tempfile( "${name}XXXXXX", DIR => bz_locations->{datadir}, UNLINK => 0);
binmode $fh, ':bytes';
print $fh $filter->serialize;
close $fh;
rename($filename, _filename($name)) or die "failed to rename $filename: $!";
$memcached->clear_bloomfilter({name => $name});
}
sub lookup {
my ($class, $name) = @_;
my $memcached = Bugzilla->memcached;
my $filename = _filename($name);
my $filter_data = $memcached->get_bloomfilter( { name => $name } );
if (!$filter_data && -f $filename) {
open my $fh, '<:bytes', $filename;
local $/ = undef;
$filter_data = <$fh>;
close $fh;
$memcached->set_bloomfilter({ name => $name, filter => $filter_data });
}
return Algorithm::BloomFilter->deserialize($filter_data);
}
1;
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