/usr/share/perl5/AtteanX/Store/LDF.pm is in libatteanx-store-ldf-perl 0.04-1.
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 | =head1 NAME
AtteanX::Store::LDF - Linked Data Fragment RDF store
=begin markdown
# STATUS
[![Build Status](https://travis-ci.org/phochste/AtteanX-Store-LDF.svg)](https://travis-ci.org/phochste/AtteanX-Store-LDF)
[![Coverage Status](https://coveralls.io/repos/phochste/AtteanX-Store-LDF/badge.svg)](https://coveralls.io/r/phochste/AtteanX-Store-LDF)
[![Kwalitee Score](http://cpants.cpanauthors.org/dist/AtteanX-Store-LDF.png)](http://cpants.cpanauthors.org/dist/AtteanX-Store-LDF)
=end markdown
=head1 SYNOPSIS
use v5.14;
use Attean;
use Attean::RDF qw(iri blank literal);
use AtteanX::Store::LDF;
my $uri = 'http://fragments.dbpedia.org/2014/en';
my $store = Attean->get_store('LDF')->new(start_url => $uri);
my $iter = $store->get_triples(undef,undef,literal("Albert Einstein"));
while (my $triple = $iter->next) {
say $triple->subject->ntriples_string .
" " .
$triple->predicate->ntriples_string .
" " .
$triple->object->ntriples_string .
" .";
}
=head1 DESCRIPTION
AtteanX::Store::LDF provides a triple-store connected to a Linked Data Fragment server.
For more information on Triple Pattern Fragments consult L<http://linkeddatafragments.org/>
=cut
use v5.14;
use warnings;
package AtteanX::Store::LDF;
our $AUTHORITY = 'cpan:KJETILK';
our $VERSION = '0.04';
use Moo;
use Attean;
use Type::Tiny::Role;
use Types::URI -all;
use RDF::LDF;
use namespace::clean;
use Carp;
with 'Attean::API::TripleStore', 'Attean::API::CostPlanner', 'MooX::Log::Any';
=head1 METHODS
Beyond the methods documented below, this class inherits methods from the
L<Attean::API::TripleStore> class.
=over 4
=item new( start_url => $start_url )
Returns a new LDF-backed storage object. The required C<start_url>
argument is a URL pointing at any Linked Data Fragment. The attribure
will be coerced, so it can be a string, a URI object, etc.
=cut
has start_url => (is => 'ro', isa => Uri, coerce => 1, required => 1);
has endpoint_url => (is => 'ro', lazy => 1, builder => '_croak_on_endpoint');
has ldf => (is => 'ro', lazy => 1, builder => '_ldf');
sub _croak_on_endpoint {
Carp::croak "endpoint_url has been deprecated, use start_url instead";
}
sub _ldf {
my $self = shift;
RDF::LDF->new(url => $self->start_url->as_string);
}
sub _term_as_string {
my ($self,$term) = @_;
if (!defined $term) {
return undef
}
elsif ($term->is_variable) {
return undef;
}
elsif ($term->is_literal) {
return $term->as_string; # includes quotes and any language or datatype
}
else {
return $term->value; # the raw IRI or blank node identifier value, without other syntax
}
}
=item count_triples_estimate( $subject, $predicate, $object )
Return the count of triples matching the specified subject, predicate and
objects.
=cut
sub count_triples_estimate {
my $self = shift;
my ($s_pattern,$p_pattern,$o_pattern) = @_;
my $ldf_iter = $self->ldf->get_statements(
$self->_term_as_string($s_pattern),
$self->_term_as_string($p_pattern),
$self->_term_as_string($o_pattern)
);
return 0 unless defined $ldf_iter;
my ($statement,$info) = $ldf_iter->();
return $info->{'void_triples'};
}
=item get_triples( $subject, $predicate, $object)
Returns a stream object of all statements matching the specified subject,
predicate and objects. Any of the arguments may be undef to match any value.
=cut
sub get_triples {
my $self = shift;
my ($s_pattern,$p_pattern,$o_pattern) = @_;
my $ldf_iter = $self->ldf->get_statements(
$self->_term_as_string($s_pattern),
$self->_term_as_string($p_pattern),
$self->_term_as_string($o_pattern)
);
return Attean::ListIterator->new(values => [] , item_type => 'Attean::API::Triple')
unless $ldf_iter;
my $iter = Attean::CodeIterator->new(
generator => sub {
my $statement = $ldf_iter->();
return () unless defined($statement);
my ($subject,$predicate,$object);
if ($statement->subject->is_resource) {
$subject = Attean::IRI->new($statement->subject->value);
}
else {
$subject = Attean::Blank->new($statement->subject->value);
}
$predicate = Attean::IRI->new($statement->predicate->value);
if ($statement->object->is_resource) {
$object = Attean::IRI->new($statement->object->value);
}
elsif ($statement->object->is_literal) {
$object = Attean::Literal->new($statement->object->value);
}
else {
$object = Attean::Blank->new($statement->object->value);
}
my @res = (
Attean::Triple->new(
subject => $subject ,
predicate => $predicate ,
object => $object
)
);
@res;
},
item_type => 'Attean::API::Triple',
);
return $iter;
}
=item cost_for_plan($plan)
Returns an cost estimation for a single LDF triple based on
estimates. The cost will be in the interval 10-1000 if the supplied
argument is a L<AtteanX::Plan::LDF::Triple>, undef otherwise.
=cut
sub cost_for_plan {
my $self = shift;
my $plan = shift;
if ($plan->isa('AtteanX::Plan::LDF::Triple')) {
my $totals = $self->count_triples_estimate();
if ($totals < 1) {
$self->log->error("Total number of triples in model were $totals, probably an error");
return 10000; # Probably a plan we don't want
}
return 10 + int(990 * $self->count_triples_estimate($plan->values) / $totals)
}
return;
}
=item plans_for_algebra($algebra)
Returns an empty plan since access_plans generates the needed plans.
=cut
sub plans_for_algebra {
return ();
}
1;
__END__
=back
=head1 SEE ALSO
L<Attean> , L<Attean::API::TripleStore>
=head1 BUGS
Please report any bugs or feature requests to through the GitHub web interface
at L<https://github.com/phochste/AtteanX-Store-LDF>.
=head1 AUTHOR
Patrick Hochstenbach C<< <patrick.hochstenbach@ugent.be> >>
Kjetil Kjernsmo E<lt>kjetilk@cpan.orgE<gt>.
=head1 COPYRIGHT
This software is copyright (c) 2015 by Patrick Hochstenbach.
This software is copyright (c) 2016 by Patrick Hochstenbach and Kjetil Kjernsmo.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
|