1 package DBM::Deep::Engine::Sector;
6 use warnings FATAL => 'all';
11 my $self = bless $_[1], $_[0];
12 Scalar::Util::weaken( $self->{engine} );
14 if ( $self->offset ) {
15 $self->{string} = $self->engine->storage->read_at(
16 $self->offset, $self->size,
20 $self->{string} = chr(0) x $self->size;
25 # Add new sectors to the sector cache.
26 $self->engine->sector_cache->{$self->offset} = $self;
32 #sub clone { DBM::Deep->_throw_error( "Must be implemented in the child class" ); }
34 sub engine { $_[0]{engine} }
35 sub offset { $_[0]{offset} }
36 sub type { $_[0]{type} }
41 return $self->engine->SIG_SIZE + $DBM::Deep::Engine::STALE_SIZE;
47 my $e = $self->engine;
49 $self->write( 0, $e->SIG_FREE );
50 $self->write( $self->base_size, chr(0) x ($self->size - $self->base_size) );
54 # $e->storage->print_at( $self->offset, $e->SIG_FREE );
55 # # Skip staleness counter
56 # $e->storage->print_at( $self->offset + $self->base_size,
57 # chr(0) x ($self->size - $self->base_size),
60 #TODO When freeing two sectors, we cannot flush them right away! This means the following:
61 # 1) The header has to understand about unflushed items.
62 # 2) Loading a sector has to go through a cache to make sure we see what's already been loaded.
63 # 3) The header should be cached.
65 my $free_meth = $self->free_meth;
66 $e->$free_meth( $self->offset, $self->size );
73 my ($start, $length) = @_;
75 return substr( $self->{string}, $start, $length );
78 return substr( $self->{string}, $start );
84 my ($start, $text) = @_;
86 substr( $self->{string}, $start, length($text) ) = $text;
93 $self->engine->add_dirty_sector( $self );
98 $self->engine->storage->print_at( $self->offset, $self->{string} );