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Ace/Local.pm  view on Meta::CPAN

sub DESTROY {
  my $self = shift;
  return unless kill 0,$self->{'pid'};
  if ($self->auto_save) {
    # save work for the user...
    $self->query('save'); 
    $self->synch;
  }
  $self->query('quit');

  # just for paranoid reasons. shouldn't be necessary
  close $self->{'write'} if $self->{'write'};  
  close $self->{'read'}  if $self->{'read'};
  waitpid($self->{pid},0) if $self->{'pid'};
}

sub encore {
  my $self = shift;
  return $self->status == STATUS_PENDING;
}

sub auto_save {
  my $self = shift;
  $self->{'auto_save'} = $_[0] if defined $_[0];
  return $self->{'auto_save'};
}

sub status {
  return $_[0]->{'status'};
}

sub error {
  my $self = shift;
  return $self->{'error'};
}

sub query {
  my $self = shift;
  my $query = shift;
  warn "query($query)\n" if $self->debug;
  if ($self->debug) {
    my $msg = $query || '';
    warn "\tquery($msg)";
  }

  return undef if $self->{'status'} == STATUS_ERROR;
  do $self->read() until $self->{'status'} != STATUS_PENDING;
  my $wtr = $self->{'write'};
  print $wtr "$query\n";
  $self->{'status'} = STATUS_PENDING;
}

sub low_read {  # hack to accomodate "uninitialized database" warning from tace
  my $self = shift;
  my $rdr = $self->{'read'};
  return undef unless $self->{'status'} == STATUS_PENDING;
  my $rin = '';
  my $data = '';
  vec($rin,fileno($rdr),1)=1;
  unless (select($rin,undef,undef,1)) {
    $self->{'status'} = STATUS_WAITING;
    return undef;
  }
  sysread($rdr,$data,READSIZE);
  return $data;
}

sub read {
  my $self = shift;
  return undef unless $self->{'status'} == STATUS_PENDING;
  my $rdr  = $self->{'read'};
  my $len  = defined $self->{'buffer'} ? length($self->{'buffer'}) : 0;
  my $plen = length($self->{'prompt'});
  my ($result, $bytes, $pos, $searchfrom);

  while (1) {

    # Read the data directly onto the end of the buffer

    $bytes = sysread($rdr, $self->{'buffer'},
		     READSIZE, $len);

    unless ($bytes > 0) {
      $self->{'status'} = STATUS_ERROR;
      return;
    }

    # check for prompt

    # The following checks were implemented using regexps and $' and
    # friends.  I have changed this to use {r}index and substr (a)
    # because they're much faster than regexps and (b) because using
    # $' and $` causes all regexps in a program to execute
    # very slowly due to excessive and unnecessary pre/post-match
    # copying -- tim.cutts@incyte.com 08 Sep 1999

    # Note, don't need to search the whole buffer for the prompt;
    # just need to search the new data and the prompt length from
    # any previous data.

    $searchfrom = ($len <= $plen) ? 0 : ($len - $plen);

    if (($pos = index($self->{'buffer'},
		      $self->{'prompt'},
		      $searchfrom)) > 0) {
      $self->{'status'} = STATUS_WAITING;
      $result = substr($self->{'buffer'}, 0, $pos);
      $self->{'buffer'} = '';
      return $result;
    }

    # return partial results for paragraph breaks

    if (($pos = rindex($self->{'buffer'}, "\n\n")) > 0) {
      $result = substr($self->{'buffer'}, 0, $pos + 2);
      $self->{'buffer'} = substr($self->{'buffer'},
				 $pos + 2);
      return $result;
    }