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	# -- 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	# Last Modified On: Sat Apr 27 17:46:53 2002
8	# Language : CPerl
9	# Update Count : 92
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	use BerkeleyDB;
19	use Fcntl;
20
21	sub new {
22	my $type = shift;
23	my $index = shift;
24	my $code = shift;
25	my $cursor;
26
27	# find the first key
28	unless ($cursor = $index->{dbh}->db_cursor()) {
29	require Carp;
30	Carp::croak("Could not open scan");
31	}
32	# Not sure about this. DB_FIRST sets $tid to no-of-records?
33	# $index->{dbh}->seq($first, $tid, DB_NEXT);
34	# register to avoid unnecessary position calls
35
36	bless {code => $code, cursor => $cursor, Index => $index},
37	$type or ref($type);
38	}
39
40	sub next {
41	my $self = shift;
42	my $cursor = $self->{cursor};
43	my ($key, $tid) = ('', '');
44
45	$cursor->c_get($key, $tid, DB_NEXT) == 0 or return;
46
47	my @tuple = split /$;/, $key;
48
49	my %tuple = (_id => $tid);
50	for (@{$self->{Index}->{attr}}) {
51	$tuple{$_} = shift @tuple;
52	}
53
54
55	if ($self->{code}) { # test condition
56	&{$self->{code}}(\%tuple)? %tuple : $self->next;
57	} else {
58	%tuple;
59	}
60	}
61
62	sub close {
63	my $self = shift;
64	delete $self->{cursor};
65	}
66
67	1;