#!/usr/bin/perl
package KiokuDB::GC::Naive::Mark;
use Moose;
use namespace::clean -except => 'meta';
with 'KiokuDB::Role::Scan' => { result_class => "KiokuDB::GC::Naive::Mark::Results" };
{
package KiokuDB::GC::Naive::Mark::Results;
use Moose;
use Set::Object;
has [qw(seen root)] => (
isa => "Set::Object",
is => "ro",
default => sub { Set::Object->new },
);
__PACKAGE__->meta->make_immutable;
}
has '+scan_all' => ( default => 0 );
has chunk_size => (
isa => "Int",
is => "ro",
default => 100,
);
sub process_block {
my ( $self, %args ) = @_;
my ( $block, $res ) = @args{qw(block results)};
my ( $seen, $root ) = map { $res->$_ } qw(seen root);
my ( $backend, $chunk_size ) = ( $self->backend, $self->chunk_size );
$root->insert(map { $_->id } @$block);
@$block = grep { not $seen->includes($_->id) } @$block;
$seen->insert(map { $_->id } @$block);
my @queue;
# recursively walk the entries making note of all seen entries
loop: {
foreach my $entry ( @$block ) {
croak("ERROR: Missing entry. Run FSCK") unless $entry;
my $id = $entry->id;
my @candidates = grep { not $seen->includes($_) } $entry->referenced_ids;
# even though we technically haven't seen them yet, insert into the
# set so that we scan less data
$seen->insert(@candidates);
push @queue, @candidates;
}
if ( @queue ) {
my @ids = ( @queue > $chunk_size ) ? ( splice @queue, -$chunk_size ) : splice @queue;
# reuse the block array so that we throw away unnecessary data
@$block = $backend->get(@ids);
redo loop;
}
}
}
__PACKAGE__->meta->make_immutable;
__PACKAGE__
__END__