Refactored Sector:: out from under Engine:: and into its own area

[dbsrgits/DBM-Deep.git] / lib / DBM / Deep / Sector / File.pm

diff --git a/lib/DBM/Deep/Sector/File.pm b/lib/DBM/Deep/Sector/File.pm
new file mode 100644 (file)
index 0000000..21f6273
--- /dev/null
+++ b/lib/DBM/Deep/Sector/File.pm
@@ -0,0 +1,104 @@
+package DBM::Deep::Sector::File;
+
+use 5.006_000;
+
+use strict;
+use warnings FATAL => 'all';
+
+use base qw( DBM::Deep::Sector );
+
+use DBM::Deep::Sector::File::Reference;
+use DBM::Deep::Sector::File::BucketList;
+use DBM::Deep::Sector::File::Index;
+use DBM::Deep::Sector::File::Null;
+use DBM::Deep::Sector::File::Scalar;
+
+my $STALE_SIZE = 2;
+
+sub base_size {
+    my $self = shift;
+    return $self->engine->SIG_SIZE + $STALE_SIZE;
+}
+
+sub free_meth { die "free_meth must be implemented in a child class" }
+
+sub free {
+    my $self = shift;
+
+    my $e = $self->engine;
+
+    $e->storage->print_at( $self->offset, $e->SIG_FREE );
+    # Skip staleness counter
+    $e->storage->print_at( $self->offset + $self->base_size,
+        chr(0) x ($self->size - $self->base_size),
+    );
+
+    my $free_meth = $self->free_meth;
+    $e->$free_meth( $self->offset, $self->size );
+
+    return;
+}
+
+=head2 load( $offset )
+
+This will instantiate and return the sector object that represents the data
+found at $offset.
+
+=cut
+
+sub load {
+    my $self = shift;
+    my ($engine, $offset) = @_;
+
+    # Add a catch for offset of 0 or 1
+    return if !$offset || $offset <= 1;
+
+    my $type = $engine->storage->read_at( $offset, 1 );
+    return if $type eq chr(0);
+
+    if ( $type eq $engine->SIG_ARRAY || $type eq $engine->SIG_HASH ) {
+        return DBM::Deep::Sector::File::Reference->new({
+            engine => $engine,
+            type   => $type,
+            offset => $offset,
+        });
+    }
+    # XXX Don't we need key_md5 here?
+    elsif ( $type eq $engine->SIG_BLIST ) {
+        return DBM::Deep::Sector::File::BucketList->new({
+            engine => $engine,
+            type   => $type,
+            offset => $offset,
+        });
+    }
+    elsif ( $type eq $engine->SIG_INDEX ) {
+        return DBM::Deep::Sector::File::Index->new({
+            engine => $engine,
+            type   => $type,
+            offset => $offset,
+        });
+    }
+    elsif ( $type eq $engine->SIG_NULL ) {
+        return DBM::Deep::Sector::File::Null->new({
+            engine => $engine,
+            type   => $type,
+            offset => $offset,
+        });
+    }
+    elsif ( $type eq $engine->SIG_DATA ) {
+        return DBM::Deep::Sector::File::Scalar->new({
+            engine => $engine,
+            type   => $type,
+            offset => $offset,
+        });
+    }
+    # This was deleted from under us, so just return and let the caller figure it out.
+    elsif ( $type eq $engine->SIG_FREE ) {
+        return;
+    }
+
+    DBM::Deep->_throw_error( "'$offset': Don't know what to do with type '$type'" );
+}
+
+1;
+__END__