lib/WAIT/IndexScan.pm

#                              -*- Mode: Perl -*- 
# IndexScan.pm -- 
# ITIID           : $ITI$ $Header $__Header$
# Author          : Ulrich Pfeifer
# Created On      : Mon Aug 12 14:05:14 1996
# Last Modified By: Ulrich Pfeifer
# Last Modified On: Sat Apr 27 17:46:53 2002
# Language        : CPerl
# Update Count    : 92
# Status          : Unknown, Use with caution!
# 
# Copyright (c) 1996-1997, Ulrich Pfeifer
# 

package WAIT::IndexScan;

use strict;
use BerkeleyDB;
use Fcntl;

sub new {
  my $type  = shift;
  my $index = shift;
  my $code  = shift;
  my $cursor;

  # find the first key
  unless ($cursor = $index->{dbh}->db_cursor()) {
    require Carp;
    Carp::croak("Could not open scan");
  }
  # Not sure about this. DB_FIRST sets $tid to no-of-records?
  # $index->{dbh}->seq($first, $tid, DB_NEXT);
  # register to avoid unnecessary position calls

  bless {code  => $code, cursor => $cursor, Index => $index},
         $type or ref($type);
}

sub next {
  my $self = shift;
  my $cursor = $self->{cursor};
  my ($key, $tid) = ('', '');

  $cursor->c_get($key, $tid, DB_NEXT) == 0 or return;

  my @tuple = split /$;/, $key;

  my %tuple = (_id => $tid);
  for (@{$self->{Index}->{attr}}) {
    $tuple{$_} = shift @tuple;
  }


  if ($self->{code}) {        # test condition
    &{$self->{code}}(\%tuple)? %tuple : $self->next;
  } else {
    %tuple;
  }
}

sub close {
  my $self = shift;
  delete $self->{cursor};
}

1;
1	ulpfr	10	# -- Mode: Perl --
2			# IndexScan.pm --
3			# ITIID : $ITI$ $Header $__Header$
4			# Author : Ulrich Pfeifer
5			# Created On : Mon Aug 12 14:05:14 1996
6			# Last Modified By: Ulrich Pfeifer
7	ulpfr	85	# Last Modified On: Sat Apr 27 17:46:53 2002
8	ulpfr	10	# Language : CPerl
9	ulpfr	85	# Update Count : 92
10	ulpfr	10	# Status : Unknown, Use with caution!
11			#
12			# Copyright (c) 1996-1997, Ulrich Pfeifer
13			#
14
15			package WAIT::IndexScan;
16
17			use strict;
18	ulpfr	85	use BerkeleyDB;
19	ulpfr	10	use Fcntl;
20
21			sub new {
22			my $type = shift;
23			my $index = shift;
24			my $code = shift;
25	ulpfr	85	my $cursor;
26	ulpfr	10
27			# find the first key
28	ulpfr	85	unless ($cursor = $index->{dbh}->db_cursor()) {
29	ulpfr	13	require Carp;
30			Carp::croak("Could not open scan");
31			}
32	ulpfr	85	# Not sure about this. DB_FIRST sets $tid to no-of-records?
33			# $index->{dbh}->seq($first, $tid, DB_NEXT);
34	ulpfr	10	# register to avoid unnecessary position calls
35
36	ulpfr	85	bless {code => $code, cursor => $cursor, Index => $index},
37			$type or ref($type);
38	ulpfr	10	}
39
40			sub next {
41			my $self = shift;
42	ulpfr	85	my $cursor = $self->{cursor};
43			my ($key, $tid) = ('', '');
44	ulpfr	10
45	ulpfr	85	$cursor->c_get($key, $tid, DB_NEXT) == 0 or return;
46	ulpfr	13
47	ulpfr	85	my @tuple = split /$;/, $key;
48	ulpfr	13
49	ulpfr	85	my %tuple = (_id => $tid);
50			for (@{$self->{Index}->{attr}}) {
51			$tuple{$_} = shift @tuple;
52			}
53	ulpfr	10
54	ulpfr	85
55			if ($self->{code}) { # test condition
56			&{$self->{code}}(\%tuple)? %tuple : $self->next;
57	ulpfr	10	} else {
58	ulpfr	85	%tuple;
59	ulpfr	10	}
60			}
61
62	ulpfr	85	sub close {
63			my $self = shift;
64			delete $self->{cursor};
65	ulpfr	10	}
66
67			1;