1 package # hide from the pauses
2 DBIx::Class::ResultSource::RowParser;
8 use List::Util 'first';
13 use base 'DBIx::Class';
15 # Accepts one or more relationships for the current source and returns an
16 # array of column names for each of those relationships. Column names are
17 # prefixed relative to the current source, in accordance with where they appear
18 # in the supplied relationships.
19 sub _resolve_prefetch {
20 my ($self, $pre, $alias, $alias_map, $order, $pref_path) = @_;
23 if (not defined $pre or not length $pre) {
26 elsif( ref $pre eq 'ARRAY' ) {
28 map { $self->_resolve_prefetch( $_, $alias, $alias_map, $order, [ @$pref_path ] ) }
31 elsif( ref $pre eq 'HASH' ) {
34 $self->_resolve_prefetch($_, $alias, $alias_map, $order, [ @$pref_path ] ),
35 $self->related_source($_)->_resolve_prefetch(
36 $pre->{$_}, "${alias}.$_", $alias_map, $order, [ @$pref_path, $_] )
41 $self->throw_exception(
42 "don't know how to resolve prefetch reftype ".ref($pre));
46 $p = $p->{$_} for (@$pref_path, $pre);
48 $self->throw_exception (
49 "Unable to resolve prefetch '$pre' - join alias map does not contain an entry for path: "
50 . join (' -> ', @$pref_path, $pre)
51 ) if (ref $p->{-join_aliases} ne 'ARRAY' or not @{$p->{-join_aliases}} );
53 my $as = shift @{$p->{-join_aliases}};
55 my $rel_info = $self->relationship_info( $pre );
56 $self->throw_exception( $self->source_name . " has no such relationship '$pre'" )
59 my $as_prefix = ($alias =~ /^.*?\.(.+)$/ ? $1.'.' : '');
61 return map { [ "${as}.$_", "${as_prefix}${pre}.$_", ] }
62 $self->related_source($pre)->columns;
66 # Takes an arrayref selection list and generates a collapse-map representing
67 # row-object fold-points. Every relationship is assigned a set of unique,
68 # non-nullable columns (which may *not even be* from the same resultset)
69 # and the collapser will use this information to correctly distinguish
70 # data of individual to-be-row-objects. See t/resultset/rowparser_internals.t
71 # for extensive RV examples
72 sub _resolve_collapse {
73 my ($self, $args, $common_args) = @_;
75 # for comprehensible error messages put ourselves at the head of the relationship chain
76 $args->{_rel_chain} ||= [ $self->source_name ];
78 # record top-level fully-qualified column index, start nodecount
80 _as_fq_idx => { %{$args->{as}} },
81 _node_idx => 1, # this is *deliberately* not 0-based
84 my ($my_cols, $rel_cols);
85 for (keys %{$args->{as}}) {
86 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
87 $rel_cols->{$1}{$2} = 1;
90 $my_cols->{$_} = {}; # important for ||= below
95 # run through relationships, collect metadata, inject non-left fk-bridges from
96 # *INNER-JOINED* children (if any)
97 for my $rel (keys %$rel_cols) {
98 my $rel_src = __get_related_source($self, $rel, $rel_cols->{$rel});
100 my $inf = $self->relationship_info ($rel);
102 $relinfo->{$rel}{is_single} = $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi';
103 $relinfo->{$rel}{is_inner} = ( $inf->{attrs}{join_type} || '' ) !~ /^left/i;
104 $relinfo->{$rel}{rsrc} = $rel_src;
106 my $cond = $inf->{cond};
113 ! first { $_ !~ /^foreign\./ } (keys %$cond)
115 ! first { $_ !~ /^self\./ } (values %$cond)
117 for my $f (keys %$cond) {
119 $_ =~ s/^ (?: foreign | self ) \.//x for ($f, $s);
120 $relinfo->{$rel}{fk_map}{$s} = $f;
122 # need to know source from *our* pov, hence $rel.
123 $my_cols->{$s} ||= { via_fk => "$rel.$f" } if (
124 defined $rel_cols->{$rel}{$f} # in fact selected
126 $relinfo->{$rel}{is_inner}
132 # if the parent is already defined, assume all of its related FKs are selected
133 # (even if they in fact are NOT in the select list). Keep a record of what we
134 # assumed, and if any such phantom-column becomes part of our own collapser,
135 # throw everything assumed-from-parent away and replace with the collapser of
136 # the parent (whatever it may be)
137 my $assumed_from_parent;
138 unless ($args->{_parent_info}{underdefined}) {
139 $assumed_from_parent->{columns} = { map
140 # only add to the list if we do not already select said columns
141 { ! exists $my_cols->{$_} ? ( $_ => 1 ) : () }
142 values %{$args->{_parent_info}{rel_condition} || {}}
145 $my_cols->{$_} = { via_collapse => $args->{_parent_info}{collapse_on} }
146 for keys %{$assumed_from_parent->{columns}};
149 # get colinfo for everything
151 my $ci = $self->columns_info;
152 $my_cols->{$_}{colinfo} = $ci->{$_} for keys %$my_cols;
157 # try to resolve based on our columns (plus already inserted FK bridges)
161 my $idset = $self->_identifying_column_set ({map { $_ => $my_cols->{$_}{colinfo} } keys %$my_cols})
163 # see if the resulting collapser relies on any implied columns,
164 # and fix stuff up if this is the case
165 my @reduced_set = grep { ! $assumed_from_parent->{columns}{$_} } @$idset;
167 $collapse_map->{-node_id} = __unique_numlist(
168 (@reduced_set != @$idset) ? @{$args->{_parent_info}{collapse_on}} : (),
172 @{$args->{_rel_chain}}[1 .. $#{$args->{_rel_chain}}],
173 ( $my_cols->{$_}{via_fk} || $_ ),
176 $common_args->{_as_fq_idx}->{$fqc};
183 # Stil don't know how to collapse - keep descending down 1:1 chains - if
184 # a related non-LEFT 1:1 is resolvable - its condition will collapse us
186 unless ($collapse_map->{-node_id}) {
189 for my $rel (keys %$relinfo) {
190 next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
192 if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
193 as => $rel_cols->{$rel},
194 _rel_chain => [ @{$args->{_rel_chain}}, $rel ],
195 _parent_info => { underdefined => 1 },
197 push @candidates, $rel_collapse->{-node_id};
201 # get the set with least amount of columns
202 # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
203 # to a single varchar)
205 ($collapse_map->{-node_id}) = sort { scalar @$a <=> scalar @$b } (@candidates);
209 # Still dont know how to collapse - see if the parent passed us anything
210 # (i.e. reuse collapser over 1:1)
211 unless ($collapse_map->{-node_id}) {
212 $collapse_map->{-node_id} = $args->{_parent_info}{collapse_on}
213 if $args->{_parent_info}{collapser_reusable};
216 # stop descending into children if we were called by a parent for first-pass
217 # and don't despair if nothing was found (there may be other parallel branches
219 if ($args->{_parent_info}{underdefined}) {
220 return $collapse_map->{-node_id} ? $collapse_map : undef
222 # nothing down the chain resolved - can't calculate a collapse-map
223 elsif (! $collapse_map->{-node_id}) {
224 $self->throw_exception ( sprintf
225 "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
227 @{$args->{_rel_chain}} > 1
228 ? sprintf (' (last member of the %s chain)', join ' -> ', @{$args->{_rel_chain}} )
234 # If we got that far - we are collapsable - GREAT! Now go down all children
235 # a second time, and fill in the rest
237 $collapse_map->{-is_optional} = 1 if $args->{_parent_info}{is_optional};
238 $collapse_map->{-node_index} = $common_args->{_node_idx}++;
240 my (@id_sets, $multis_in_chain);
241 for my $rel (sort keys %$relinfo) {
243 $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
244 as => { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
245 _rel_chain => [ @{$args->{_rel_chain}}, $rel],
247 collapse_on => [ @{$collapse_map->{-node_id}} ],
249 rel_condition => $relinfo->{$rel}{fk_map},
251 is_optional => $collapse_map->{-is_optional},
253 # if this is a 1:1 our own collapser can be used as a collapse-map
254 # (regardless of left or not)
255 collapser_reusable => $relinfo->{$rel}{is_single},
259 $collapse_map->{$rel}{-is_single} = 1 if $relinfo->{$rel}{is_single};
260 $collapse_map->{$rel}{-is_optional} ||= 1 unless $relinfo->{$rel}{is_inner};
261 push @id_sets, @{ $collapse_map->{$rel}{-branch_id} };
264 $collapse_map->{-branch_id} = __unique_numlist( @id_sets, @{$collapse_map->{-node_id}} );
266 return $collapse_map;
269 # Takes an arrayref of {as} dbic column aliases and the collapse and select
270 # attributes from the same $rs (the selector requirement is a temporary
271 # workaround... I hope), and returns a coderef capable of:
272 # my $me_pref_clps = $coderef->([$rs->cursor->next/all])
273 # Where the $me_pref_clps arrayref is the future argument to inflate_result()
275 # For an example of this coderef in action (and to see its guts) look at
276 # t/resultset/rowparser_internals.t
278 # This is a huge performance win, as we call the same code for # every row
279 # returned from the db, thus avoiding repeated method lookups when traversing
282 # Also since the coderef is completely stateless (the returned structure is
283 # always fresh on every new invocation) this is a very good opportunity for
284 # memoization if further speed improvements are needed
286 # The way we construct this coderef is somewhat fugly, although the result is
287 # really worth it. The final coderef does not perform any kind of recursion -
288 # the entire nested structure constructor is rolled out into a single scope.
290 # In any case - the output of this thing is meticulously micro-tested, so
291 # any sort of adjustment/rewrite should be relatively easy (fsvo relatively)
294 my ($self, $args) = @_;
296 my $inflate_index = { map
297 { $args->{inflate_map}[$_] => $_ }
298 ( 0 .. $#{$args->{inflate_map}} )
303 # the non-collapsing assembler is easy
304 # FIXME SUBOPTIMAL there could be a yet faster way to do things here, but
305 # need to try an actual implementation and benchmark it:
307 # <timbunce_> First setup the nested data structure you want for each row
308 # Then call bind_col() to alias the row fields into the right place in
309 # the data structure, then to fetch the data do:
310 # push @rows, dclone($row_data_struct) while ($sth->fetchrow);
312 if (!$args->{collapse}) {
313 $parser_src = sprintf('$_ = %s for @{$_[0]}', __visit_infmap_simple(
315 { rsrc => $self }, # need the $rsrc to sanity-check inflation map once
318 # change the quoted placeholders to unquoted alias-references
319 $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$_->[$1]"/gex;
322 # the collapsing parser is more complicated - it needs to keep a lot of state
326 my $collapse_map = $self->_resolve_collapse ({
328 # only consider real columns (not functions) during collapse resolution
329 # this check shouldn't really be here, as fucktards are not supposed to
330 # alias random crap to existing column names anyway, but still - just in
332 # FIXME !!!! - this does not yet deal with unbalanced selectors correctly
333 # (it is now trivial as the attrs specify where things go out of sync
336 { ref $args->{selection}[$inflate_index->{$_}] ? () : ( $_ => $inflate_index->{$_} ) }
341 my $top_branch_idx_list = join (', ', @{$collapse_map->{-branch_id}});
343 my $top_node_id_path = join ('', map
344 { "{'\xFF__IDVALPOS__${_}__\xFF'}" }
345 @{$collapse_map->{-node_id}}
348 my $rel_assemblers = __visit_infmap_collapse (
349 $inflate_index, $collapse_map
352 $parser_src = sprintf (<<'EOS', $top_branch_idx_list, $top_node_id_path, $rel_assemblers);
353 ### BEGIN STRING EVAL
355 my ($rows_pos, $result_pos, $cur_row, @cur_row_ids, @collapse_idx, $is_new_res) = (0,0);
357 # this loop is a bit arcane - the rationale is that the passed in
358 # $_[0] will either have only one row (->next) or will have all
359 # rows already pulled in (->all and/or unordered). Given that the
360 # result can be rather large - we reuse the same already allocated
361 # array, since the collapsed prefetch is smaller by definition.
362 # At the end we cut the leftovers away and move on.
364 ( ( $rows_pos >= 0 and $_[0][$rows_pos++] ) or do { $rows_pos = -1; undef } )
366 ($_[1] and $_[1]->())
369 $cur_row_ids[$_] = defined $cur_row->[$_] ? $cur_row->[$_] : "\xFF\xFFN\xFFU\xFFL\xFFL\xFF\xFF"
370 for (%1$s); # the top branch_id includes all id values
372 $is_new_res = ! $collapse_idx[1]%2$s and (
373 $_[1] and $result_pos and (unshift @{$_[2]}, $cur_row) and last
378 $_[0][$result_pos++] = $collapse_idx[1]%2$s
382 splice @{$_[0]}, $result_pos; # truncate the passed in array for cases of collapsing ->all()
386 # !!! note - different var than the one above
387 # change the quoted placeholders to unquoted alias-references
388 $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$cur_row->[$1]"/gex;
389 $parser_src =~ s/ \' \xFF__IDVALPOS__(\d+)__\xFF \' /"\$cur_row_ids[$1]"/gex;
395 # the simple non-collapsing nested structure recursor
396 sub __visit_infmap_simple {
397 my ($val_idx, $args) = @_;
401 for (keys %$val_idx) {
402 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
403 $rel_cols->{$1}{$2} = $val_idx->{$_};
406 $my_cols->{$_} = $val_idx->{$_};
410 for my $rel (sort keys %$rel_cols) {
413 #my $optional = $args->{is_optional};
414 #$optional ||= ($args->{rsrc}->relationship_info($rel)->{attrs}{join_type} || '') =~ /^left/i;
416 push @relperl, join ' => ', perlstring($rel), __visit_infmap_simple($rel_cols->{$rel}, {
417 rsrc => __get_related_source($args->{rsrc}, $rel, $rel_cols->{$rel}),
420 #is_optional => $optional,
423 # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t
424 #if ($optional and my @branch_null_checks = map
425 # { "(! defined '\xFF__VALPOS__${_}__\xFF')" }
426 # sort { $a <=> $b } values %{$rel_cols->{$rel}}
428 # $relperl[-1] = sprintf ( '(%s) ? ( %s => [] ) : ( %s )',
429 # join (' && ', @branch_null_checks ),
436 my $me_struct = keys %$my_cols
437 ? __visit_dump({ map { $_ => "\xFF__VALPOS__$my_cols->{$_}__\xFF" } (keys %$my_cols) })
441 return sprintf '[%s]', join (',',
443 @relperl ? sprintf ('{ %s }', join (',', @relperl)) : (),
447 # the collapsing nested structure recursor
448 sub __visit_infmap_collapse {
450 my ($val_idx, $collapse_map, $parent_info) = @_;
454 for (keys %$val_idx) {
455 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
456 $rel_cols->{$1}{$2} = $val_idx->{$_};
459 $my_cols->{$_} = $val_idx->{$_};
463 my $sequenced_node_id = join ('', map
464 { "{'\xFF__IDVALPOS__${_}__\xFF'}" }
465 @{$collapse_map->{-node_id}}
468 my $me_struct = keys %$my_cols
469 ? __visit_dump([{ map { $_ => "\xFF__VALPOS__$my_cols->{$_}__\xFF" } (keys %$my_cols) }])
472 my $node_idx_ref = sprintf '$collapse_idx[%d]%s', $collapse_map->{-node_index}, $sequenced_node_id;
474 my $parent_idx_ref = sprintf( '$collapse_idx[%d]%s[1]{%s}',
475 @{$parent_info}{qw/node_idx sequenced_node_id/},
476 perlstring($parent_info->{relname}),
480 if ($collapse_map->{-node_index} == 1) {
481 push @src, sprintf( '%s ||= %s;',
486 elsif ($collapse_map->{-is_single}) {
487 push @src, sprintf ( '%s ||= %s%s;',
490 $me_struct ? " ||= $me_struct" : '',
494 push @src, sprintf('push @{%s}, %s%s unless %s;',
497 $me_struct ? " ||= $me_struct" : '',
503 #my $known_defined = { %{ $parent_info->{known_defined} || {} } };
504 #$known_defined->{$_}++ for @{$collapse_map->{-node_id}};
506 for my $rel (sort keys %$rel_cols) {
508 push @src, sprintf( '%s[1]{%s} ||= [];', $node_idx_ref, perlstring($rel) )
509 unless $collapse_map->{$rel}{-is_single};
511 push @src, __visit_infmap_collapse($rel_cols->{$rel}, $collapse_map->{$rel}, {
512 node_idx => $collapse_map->{-node_index},
513 sequenced_node_id => $sequenced_node_id,
516 #known_defined => $known_defined,
519 # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t
520 #if ($collapse_map->{$rel}{-is_optional} and my @null_checks = map
521 # { "(! defined '\xFF__IDVALPOS__${_}__\xFF')" }
522 # sort { $a <=> $b } grep
523 # { ! $known_defined->{$_} }
524 # @{$collapse_map->{$rel}{-node_id}}
526 # $src[-1] = sprintf( '(%s) or %s',
527 # join (' || ', @null_checks ),
536 # adding a dep on MoreUtils *just* for this is retarded
537 sub __unique_numlist {
538 [ sort { $a <=> $b } keys %{ {map { $_ => 1 } @_ }} ]
541 # This error must be thrown from two distinct codepaths, joining them is
542 # rather hard. Go for this hack instead.
543 sub __get_related_source {
544 my ($rsrc, $rel, $relcols) = @_;
546 $rsrc->related_source ($rel)
548 $rsrc->throw_exception(sprintf(
549 "Can't inflate prefetch into non-existent relationship '%s' from '%s', "
550 . "check the inflation specification (columns/as) ending in '...%s.%s'.",
554 (sort { length($a) <=> length ($b) } keys %$relcols)[0],
558 # keep our own DD object around so we don't have to fitz with quoting
561 # we actually will be producing functional perl code here,
562 # thus no second-guessing of what these globals might have
563 # been set to. DO NOT CHANGE!
564 ($dumper_obj ||= do {
565 require Data::Dumper;
566 Data::Dumper->new([])
576 ->Indent (0) # faster but harder to read, perhaps leave at 1 ?
577 })->Values ([$_[0]])->Dump;