lib/DBM/Deep/Engine/Sector/Null.pm

   1 package DBM::Deep::Engine::Sector::Null;
   2
   3 use 5.006_000;
   4
   5 use strict;
   6 use warnings FATAL => 'all';
   7
   8 use base qw( DBM::Deep::Engine::Sector::Data );
   9
  10 sub type { $_[0]{engine}->SIG_NULL }
  11 sub data_length { 0 }
  12 sub data { return }
  13
  14 sub _init {
  15     my $self = shift;
  16
  17     my $engine = $self->engine;
  18
  19     unless ( $self->offset ) {
  20         my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1;
  21
  22         $self->{offset} = $engine->_request_data_sector( $self->size );
  23         $engine->storage->print_at( $self->offset, $self->type ); # Sector type
  24         # Skip staleness counter
  25         $engine->storage->print_at( $self->offset + $self->base_size,
  26             pack( $StP{$engine->byte_size}, 0 ),  # Chain loc
  27             pack( $StP{1}, $self->data_length ),  # Data length
  28             chr(0) x $leftover,                   # Zero-fill the rest
  29         );
  30
  31         return;
  32     }
  33 }
  34
  35 1;
  36 __END__