This file is indexed.

/usr/share/perl5/Cache/File/Heap.pm is in libcache-perl 2.11-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
=head1 NAME

Cache::File::Heap - A file based heap for use by Cache::File

=head1 SYNOPSIS

  use Cache::File::Heap;

  $heap = Cache::File::Heap->new('/path/to/some/heap/file');
  $heap->add($key, $val);
  ($key, $val) = $heap->minimum;
  ($key, $val) = $heap->extract_minimum;
  $heap->delete($key, $val);

=head1 DESCRIPTION

This module is a wrapper around a Berkeley DB using a btree structure to
implement a heap.  It is specifically for use by Cache::File for storing
expiry times (although with a bit of work it could be made more general).

See LIMITATIONS below.

=cut
package Cache::File::Heap;

require 5.006;
use strict;
use warnings;
use DB_File;
use Carp;

use fields qw(db dbhash);

our $VERSION = '2.11';

# common info object
my $BTREEINFO = new DB_File::BTREEINFO;
$BTREEINFO->{compare} = \&_Num_Compare;
$BTREEINFO->{flags} = R_DUP;


=head1 CONSTRUCTOR

  my $heap = Cache::File::Heap->new( [$dbfile] );

The heap constructor takes an optional argument which is the name of the
database file to open.  If specified, it will attempt to open the database
during construction.  A new Cache::File::Heap blessed reference will be
returned, or undef if the open failed.

=cut

sub new {
    my Cache::File::Heap $self = shift;

    $self = fields::new($self) unless ref $self;

    if (@_) {
        $self->open(@_) or return undef;
    }

    return $self;
}


=head1 METHODS

=over

=item $h->open($dbfile)

Opens the specified database file.

=cut

sub open {
    my Cache::File::Heap $self = shift;
    my ($dbfile) = @_;

    $self->close();

    my %dbhash;
    my $db = tie %dbhash, 'DB_File', $dbfile, O_CREAT|O_RDWR, 0666, $BTREEINFO
        or return undef;

    $self->{db} = $db;
    $self->{dbhash} = \%dbhash;

    return 1;
}

=item $h->close()

Closes a previously opened heap database.  Note that the database will be
automatically closed when the heap reference is destroyed.

=cut

sub close {
    my Cache::File::Heap $self = shift;
    $self->{db} = undef;
    untie %{$self->{dbhash}};
    $self->{dbhash} = undef;
}

=item $h->add($key, $val)

Adds a key and value pair to the heap.  Currently the key should be a number,
whilst the value may be any scalar.  Invokes 'die' on failure (use eval to
catch it).

=cut

sub add {
    my Cache::File::Heap $self = shift;
    my ($key, $val) = @_;
    defined $key or croak "key undefined";
    defined $val or croak "value undefined";
    # return code from DB_File is 0 on success.....
    $self->_db->put($key, $val) and die "Heap add failed: $@";
}

=item $h->delete($key, $val)

Removes a key and value pair from the heap.  Returns 1 if the pair was found
and removed, or 0 otherwise.

=cut

sub delete {
    my Cache::File::Heap $self = shift;
    my ($key, $val) = @_;
    defined $key or croak "key undefined";
    defined $val or croak "value undefined";
    # return code from DB_File is 0 on success.....
    $self->_db->del_dup($key, $val) and return 0;
    return 1;
}

=item ($key, $val) = $h->minimum()

In list context, returns the smallest key and value pair from the heap.  In
scalar context only the key is returned.  Note smallest is defined via a
numerical comparison (hence keys should always be numbers).

=cut

sub minimum {
    my Cache::File::Heap $self = shift;
    my ($key, $val) = (0,0);
    $self->_db->seq($key, $val, R_FIRST)
        and return undef;
    return wantarray? ($key, $val) : $key;
}

=item ($key, $vals) = $h->minimum_dup()

In list context, returns the smallest key and an array reference containing
all the values for that key from the heap.  In scalar context only the key is
returned.

=cut

sub minimum_dup {
    my Cache::File::Heap $self = shift;
    my $db = $self->_db;
    my ($key, $val) = (0,0);
    $db->seq($key, $val, R_FIRST)
        and return undef;
    return wantarray? ($key, [ $db->get_dup($key) ]) : $key;
}

=item ($key, $val) = $h->extract_minimum()

As for $h->minimum(), but the key and value pair is removed from the heap.

=cut

sub extract_minimum {
    my Cache::File::Heap $self = shift;
    my $db = $self->_db;
    my ($key, $val) = (0,0);
    $db->seq($key, $val, R_FIRST)
        and return undef;
    $db->del_dup($key, $val);
    return wantarray? ($key, $val) : $key;
}

=item ($key, $vals) = $h->extract_minimum_dup()

As for $h->minimum_dup(), but all the values are removed from the heap.

=cut

sub extract_minimum_dup {
    my Cache::File::Heap $self = shift;
    my $db = $self->_db;
    my ($key, $val) = (0,0);
    $db->seq($key, $val, R_FIRST)
        and return undef;
    my @values = $db->get_dup($key) if wantarray;
    $db->del($key);
    # bugfix for broken db1 - not all values are removed the first time
    $db->del($key);
    return wantarray? ($key, \@values) : $key;
}

=back

=cut


sub _db {
    my Cache::File::Heap $self = shift;
    my $db = $self->{db};
    croak "Heap not opened" unless $db;
}

sub _Num_Compare {
    my ($key1, $key2) = @_;

    # somehow we can get undefined keys here?  Probably a db bug.

    if (not defined $key1 and not defined $key2) {
        return 0
    }
    elsif (defined $key1 and not defined $key2) {
        return 1;
    }
    elsif (not defined $key1 and defined $key2) {
        return -1;
    }
    else {
        return $key1 <=> $key2;
    }
}


1;
__END__

=head1 SEE ALSO

Cache::File

=head1 AUTHOR

 Chris Leishman <chris@leishman.org>
 Based on work by DeWitt Clinton <dewitt@unto.net>

=head1 COPYRIGHT

 Copyright (C) 2003-2006 Chris Leishman.  All Rights Reserved.

This module is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND,
either expressed or implied. This program is free software; you can
redistribute or modify it under the same terms as Perl itself.

$Id: Heap.pm,v 1.6 2006/01/31 15:23:58 caleishm Exp $

=cut