/usr/share/perl5/RDF/Trine/Iterator/Bindings.pm is in librdf-trine-perl 1.019-1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 | # RDF::Trine::Iterator::Bindings
# -----------------------------------------------------------------------------
=head1 NAME
RDF::Trine::Iterator::Bindings - Iterator class for bindings query results
=head1 VERSION
This document describes RDF::Trine::Iterator::Bindings version 1.019
=head1 SYNOPSIS
use RDF::Trine::Iterator::Bindings;
my $iterator = RDF::Trine::Iterator::Bindings->new( \&data, \@names );
while (my $row = $iterator->next) {
# $row is a HASHref containing variable name -> RDF Term bindings
my @vars = keys %$row;
print $row->{ 'var' }->as_string;
}
=head1 METHODS
Beyond the methods documented below, this class inherits methods from the
L<RDF::Trine::Iterator> class.
=over 4
=cut
package RDF::Trine::Iterator::Bindings;
use utf8;
use strict;
use warnings;
no warnings 'redefine';
use Data::Dumper;
use JSON 2.0;
use Text::Table;
use Log::Log4perl;
use Scalar::Util qw(blessed reftype);
use RDF::Trine::Iterator::Bindings::Materialized;
use RDF::Trine::Serializer::Turtle;
use RDF::Trine::Iterator qw(smap);
use base qw(RDF::Trine::Iterator);
use Carp qw(croak);
our ($VERSION);
BEGIN {
$VERSION = '1.019';
}
=item C<new ( \@results, \@names, %args )>
=item C<new ( \&results, \@names, %args )>
Returns a new SPARQL Result interator object. Results must be either
a reference to an array containing results or a CODE reference that
acts as an iterator, returning successive items when called, and
returning undef when the iterator is exhausted.
=cut
sub new {
my $class = shift;
my $stream = shift || sub { undef };
my $names = shift || [];
my %args = @_;
my $type = 'bindings';
my $self = $class->SUPER::new( $stream, $type, $names, %args );
my $s = $args{ sorted_by } || [];
$self->{sorted_by} = $s;
return $self;
}
sub _new {
my $class = shift;
my $stream = shift;
my $type = shift;
my $names = shift;
my %args = @_;
return $class->new( $stream, $names, %args );
}
=item C<< materialize >>
Returns a materialized version of the current binding iterator.
The materialization process will leave this iterator empty. The materialized
iterator that is returned should be used for any future need for the iterator's
data.
=cut
sub materialize {
my $self = shift;
my @data = $self->get_all;
my @args = $self->construct_args;
return $self->_mclass->_new( \@data, @args );
}
sub _mclass {
return 'RDF::Trine::Iterator::Bindings::Materialized';
}
=item C<< project ( @columns ) >>
Returns a new stream that projects the current bindings to only the given columns.
=cut
sub project {
my $self = shift;
my $class = ref($self);
my @proj = @_;
my $sub = sub {
my $row = $self->next;
return unless ($row);
my $p = { map { $_ => $row->{ $_ } } @proj };
return $p;
};
my $args = $self->_args();
my $proj = $class->new( $sub, [@proj], %$args );
return $proj;
}
=item C<join_streams ( $stream, $stream )>
Performs a natural, nested loop join of the two streams, returning a new stream
of joined results.
=cut
sub join_streams {
my $self = shift;
my $a = shift;
my $b = shift;
# my $bridge = shift;
my %args = @_;
# Carp::confess unless ($a->isa('RDF::Trine::Iterator::Bindings'));
# Carp::confess unless ($b->isa('RDF::Trine::Iterator::Bindings'));
my $l = Log::Log4perl->get_logger("rdf.trine.iterator.bindings");
my @join_sorted_by;
if (my $o = $args{ orderby }) {
my $req_sort = join(',', map { $_->[1]->name => $_->[0] } @$o);
my $a_sort = join(',', $a->sorted_by);
my $b_sort = join(',', $b->sorted_by);
if ($l->is_debug) {
$l->debug('---------------------------');
$l->debug('REQUESTED SORT in JOIN: ' . Dumper($req_sort));
$l->debug('JOIN STREAM SORTED BY: ' . Dumper($a_sort));
$l->debug('JOIN STREAM SORTED BY: ' . Dumper($b_sort));
}
my $actual_sort;
if (substr( $a_sort, 0, length($req_sort) ) eq $req_sort) {
$l->debug("first stream is already sorted. using it in the outer loop.");
} elsif (substr( $b_sort, 0, length($req_sort) ) eq $req_sort) {
$l->debug("second stream is already sorted. using it in the outer loop.");
($a,$b) = ($b,$a);
} else {
my $a_common = join('!', $a_sort, $req_sort);
my $b_common = join('!', $b_sort, $req_sort);
if ($a_common =~ qr[^([^!]+)[^!]*!\1]) { # shared prefix between $a_sort and $req_sort?
$l->debug("first stream is closely sorted ($1).");
} elsif ($b_common =~ qr[^([^!]+)[^!]*!\1]) { # shared prefix between $b_sort and $req_sort?
$l->debug("second stream is closely sorted ($1).");
($a,$b) = ($b,$a);
}
}
@join_sorted_by = ($a->sorted_by, $b->sorted_by);
}
my $stream = $self->nested_loop_join( $a, $b, %args );
$l->debug("JOINED stream is sorted by: " . join(',', @join_sorted_by));
$stream->{sorted_by} = \@join_sorted_by;
return $stream;
}
=item C<< nested_loop_join ( $outer, $inner ) >>
Performs a natural, nested loop join of the two streams, returning a new stream
of joined results.
Note that the values from the C<< $inner >> iterator are fully materialized for
this join, and the results of the join are in the order of values from the
C<< $outer >> iterator. This suggests that:
* If sorting needs to be preserved, the C<< $outer >> iterator should be used to
determine the result ordering.
* If one iterator is much smaller than the other, it should likely be used as
the C<< $inner >> iterator since materialization will require less total memory.
=cut
sub nested_loop_join {
my $self = shift;
my $astream = shift;
my $bstream = shift;
# my $bridge = shift;
my %args = @_;
# Carp::confess unless ($astream->isa('RDF::Trine::Iterator::Bindings'));
# Carp::confess unless ($bstream->isa('RDF::Trine::Iterator::Bindings'));
my $l = Log::Log4perl->get_logger("rdf.trine.iterator.bindings");
my @names = RDF::Trine::_uniq( map { $_->binding_names() } ($astream, $bstream) );
my $a = $astream->project( @names );
my $b = $bstream->project( @names );
my @data = $b->get_all();
no warnings 'uninitialized';
my $inner_index;
my $rowa;
my $need_new_a = 1;
my $sub = sub {
OUTER: while (1) {
if ($need_new_a) {
$l->debug("### fetching new outer tuple");
$rowa = $a->next;
$inner_index = 0;
$need_new_a = 0;
}
$l->debug("OUTER: " . Dumper($rowa));
return unless ($rowa);
LOOP: while ($inner_index <= $#data) {
my $rowb = $data[ $inner_index++ ];
$l->debug("- INNER[ $inner_index ]: " . Dumper($rowb));
$l->debug("[--JOIN--] " . join(' ', map { my $row = $_; '{' . join(', ', map { join('=', $_, ($row->{$_}) ? $row->{$_}->as_string : '(undef)') } (keys %$row)) . '}' } ($rowa, $rowb)));
my %keysa = map {$_=>1} (keys %$rowa);
my @shared = grep { $keysa{ $_ } } (keys %$rowb);
foreach my $key (@shared) {
my $val_a = $rowa->{ $key };
my $val_b = $rowb->{ $key };
my $defined = 0;
foreach my $n ($val_a, $val_b) {
$defined++ if (defined($n));
}
if ($defined == 2) {
my $equal = $val_a->equal( $val_b );
unless ($equal) {
$l->debug("can't join because mismatch of $key (" . join(' <==> ', map {$_->as_string} ($val_a, $val_b)) . ")");
next LOOP;
}
}
}
my $row = { (map { $_ => $rowa->{$_} } grep { defined($rowa->{$_}) } keys %$rowa), (map { $_ => $rowb->{$_} } grep { defined($rowb->{$_}) } keys %$rowb) };
if ($l->is_debug) {
$l->debug("JOINED:");
foreach my $key (keys %$row) {
$l->debug("$key\t=> " . $row->{ $key }->as_string);
}
}
return $row;
}
$need_new_a = 1;
}
};
my $args = $astream->_args;
return $astream->_new( $sub, 'bindings', \@names, %$args );
}
=item C<< sorted_by >>
=cut
sub sorted_by {
my $self = shift;
my $sorted = $self->{sorted_by};
return @$sorted;
}
=item C<< binding_value_by_name ( $name ) >>
Returns the binding of the named variable in the current result.
=cut
sub binding_value_by_name {
my $self = shift;
my $name = shift;
my $row = ($self->open) ? $self->current : $self->next;
if (exists( $row->{ $name } )) {
return $row->{ $name };
} else {
# warn "No variable named '$name' is present in query results.\n";
return;
}
}
=item C<< binding_value ( $i ) >>
Returns the binding of the $i-th variable in the current result.
=cut
sub binding_value {
my $self = shift;
my $val = shift;
my @names = $self->binding_names;
return $self->binding_value_by_name( $names[ $val ] );
}
=item C<binding_values>
Returns a list of the binding values from the current result.
=cut
sub binding_values {
my $self = shift;
my $row = ($self->open) ? $self->current : $self->next;
return @{ $row }{ $self->binding_names };
}
=item C<binding_names>
Returns a list of the binding names.
=cut
sub binding_names {
my $self = shift;
my $names = $self->{_names};
return @$names;
}
=item C<binding_name ( $i )>
Returns the name of the $i-th result column.
=cut
sub binding_name {
my $self = shift;
my $val = shift;
my $names = $self->{_names};
return $names->[ $val ];
}
=item C<bindings_count>
Returns the number of variable bindings in the current result.
=cut
sub bindings_count {
my $self = shift;
my $names = $self->{_names};
return scalar( @$names ) if (scalar(@$names));
return 0;
}
=item C<is_bindings>
Returns true if the underlying result is a set of variable bindings.
=cut
sub is_bindings {
my $self = shift;
return 1;
}
=item C<as_json ( $max_size )>
Returns a JSON serialization of the stream data.
=cut
sub as_json {
my $self = shift;
my $max_result_size = shift || 0;
my $width = $self->bindings_count;
# my $bridge = $self->bridge;
my @variables;
for (my $i=0; $i < $width; $i++) {
my $name = $self->binding_name($i);
push(@variables, $name) if $name;
}
my $count = 0;
my @sorted = $self->sorted_by;
my $order = scalar(@sorted) ? JSON::true : JSON::false;
my $dist = $self->_args->{distinct} ? JSON::true : JSON::false;
my $data = {
head => { vars => \@variables },
results => { ordered => $order, distinct => $dist, bindings => [] },
};
my @bindings;
while (my $row = $self->next) {
my %row = map { format_node_json($row->{$_}, $_) } (keys %$row);
push(@{ $data->{results}{bindings} }, \%row);
last if ($max_result_size and ++$count >= $max_result_size);
}
return to_json( $data );
}
=item C<as_xml ( $max_size )>
Returns an XML serialization of the stream data.
=cut
sub as_xml {
my $self = shift;
my $max_result_size = shift || 0;
my $string = '';
open( my $fh, '>', \$string );
$self->print_xml( $fh, $max_result_size );
close($fh);
return $string;
}
=item C<as_string ( $max_size [, \$count] )>
Returns a string table serialization of the stream data.
=cut
sub as_string {
my $self = shift;
my $max_result_size = shift || 0;
my $rescount = shift;
my @names = $self->binding_names;
my $headers = \@names;
my @rows;
my $count = 0;
while (my $row = $self->next) {
push(@rows, [ map { blessed($_) ? RDF::Trine::Serializer::Turtle->node_as_concise_string($_) : '' } @{ $row }{ @names } ]);
last if ($max_result_size and ++$count >= $max_result_size);
}
if (ref($rescount)) {
$$rescount = scalar(@rows);
}
my @rule = qw(- +);
my @headers = (\q"| ");
push(@headers, map { $_ => \q" | " } @$headers);
pop @headers;
push @headers => (\q" |");
if ('ARRAY' eq ref $rows[0]) {
if (@$headers == @{ $rows[0] }) {
my $table = Text::Table->new(@headers);
$table->rule(@rule);
$table->body_rule(@rule);
$table->load(@rows);
return join('',
$table->rule(@rule),
$table->title,
$table->rule(@rule),
map({ $table->body($_) } 0 .. @rows),
$table->rule(@rule)
);
} else {
die("make_table() rows must be an AoA with rows being same size as headers");
}
} else {
return '';
}
}
=item C<< as_statements ( $pattern | @names ) >>
Returns a L<RDF::Trine::Iterator::Graph> with the statements of the stream.
If C<$pattern>, an RDF::Trine::Pattern object, is given as an argument, each of
its triples are instantiated with variable bindings from each row of the
iterator, and returned as RDF::Trine::Statement objects from a new
RDF::Trine::Iterator::Graph iterator.
If 3 variable C<@names> are supplied, their corresponding variable bindings
in each row of the iterator are used (in order) as the subject, predicate, and
object of new RDF::Trine::Statement objects and returned from a new
RDF::Trine::Iterator::Graph iterator.
=cut
sub as_statements {
my $self = shift;
my @names = @_;
if (scalar(@names) == 1 and $names[0]->can('triples')) {
my $pattern = shift;
my @triples = $pattern->triples;
my @queue;
my $sub = sub {
while (1) {
if (scalar(@queue)) {
return shift(@queue);
}
my $row = $self->next;
return unless (defined $row);
foreach my $t (@triples) {
my $st = $t->bind_variables($row);
if ($st->rdf_compatible) {
push(@queue, $st);
}
}
}
};
return RDF::Trine::Iterator::Graph->new( $sub );
} else {
my $sub = sub {
my $row = $self->next;
return unless (defined $row);
my @values = @{ $row }{ @names };
my $statement = (scalar(@values) == 3 or not(defined($values[3])))
? RDF::Trine::Statement->new( @values[ 0 .. 2 ] )
: RDF::Trine::Statement::Quad->new( @values );
return $statement;
};
return RDF::Trine::Iterator::Graph->new( $sub );
}
}
=item C<< print_xml ( $fh, $max_size ) >>
Prints an XML serialization of the stream data to the filehandle $fh.
=cut
sub print_xml {
my $self = shift;
my $fh = shift;
my $max_result_size = shift || 0;
my $width = $self->bindings_count;
my @variables;
for (my $i=0; $i < $width; $i++) {
my $name = $self->binding_name($i);
push(@variables, $name) if $name;
}
print {$fh} <<"END";
<?xml version="1.0" encoding="utf-8"?>
<sparql xmlns="http://www.w3.org/2005/sparql-results#">
<head>
END
my $t = join("\n", map { qq(\t<variable name="$_"/>) } @variables);
if ($t) {
print {$fh} "${t}\n";
}
print {$fh} <<"END";
</head>
<results>
END
my $count = 0;
while (my $row = $self->next) {
my @row;
print {$fh} "\t\t<result>\n";
for (my $i = 0; $i < $width; $i++) {
my $name = $self->binding_name($i);
my $value = $row->{ $name };
print {$fh} "\t\t\t" . $self->format_node_xml($value, $name) . "\n";
}
print {$fh} "\t\t</result>\n";
last if ($max_result_size and ++$count >= $max_result_size);
}
print {$fh} "</results>\n";
print {$fh} "</sparql>\n";
}
=begin private
=item C<format_node_json ( $node, $name )>
Returns a string representation of C<$node> for use in a JSON serialization.
=end private
=cut
sub format_node_json {
# my $bridge = shift;
# return unless ($bridge);
my $node = shift;
my $name = shift;
my $node_label;
if(!defined $node) {
return;
} elsif ($node->isa('RDF::Trine::Node::Resource')) {
$node_label = $node->uri_value;
return $name => { type => 'uri', value => $node_label };
} elsif ($node->isa('RDF::Trine::Node::Literal')) {
$node_label = $node->literal_value;
return $name => { type => 'literal', value => $node_label };
} elsif ($node->isa('RDF::Trine::Node::Blank')) {
$node_label = $node->blank_identifier;
return $name => { type => 'bnode', value => $node_label };
} else {
return;
}
}
=item C<< construct_args >>
Returns the arguments necessary to pass to the stream constructor _new
to re-create this stream (assuming the same closure as the first
argument).
=cut
sub construct_args {
my $self = shift;
my $type = $self->type;
my @names = $self->binding_names;
my $args = $self->_args || {};
return ($type, \@names, %{ $args });
}
1;
__END__
=back
=head1 DEPENDENCIES
L<JSON|JSON>
L<Scalar::Util|Scalar::Util>
=head1 BUGS
Please report any bugs or feature requests to through the GitHub web interface
at L<https://github.com/kasei/perlrdf/issues>.
=head1 AUTHOR
Gregory Todd Williams C<< <gwilliams@cpan.org> >>
=head1 COPYRIGHT
Copyright (c) 2006-2012 Gregory Todd Williams. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
=cut
|