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, $as, $as_fq_idx, $rel_chain, $parent_info, $node_idx_ref) = @_;
75 # for comprehensible error messages put ourselves at the head of the relationship chain
76 $rel_chain ||= [ $self->source_name ];
78 # record top-level fully-qualified column index
79 $as_fq_idx ||= { %$as };
81 my ($my_cols, $rel_cols);
83 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
84 $rel_cols->{$1}{$2} = 1;
87 $my_cols->{$_} = {}; # important for ||= below
92 # run through relationships, collect metadata, inject non-left fk-bridges from
93 # *INNER-JOINED* children (if any)
94 for my $rel (keys %$rel_cols) {
95 my $rel_src = __get_related_source($self, $rel, $rel_cols->{$rel});
97 my $inf = $self->relationship_info ($rel);
99 $relinfo->{$rel}{is_single} = $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi';
100 $relinfo->{$rel}{is_inner} = ( $inf->{attrs}{join_type} || '' ) !~ /^left/i;
101 $relinfo->{$rel}{rsrc} = $rel_src;
103 my $cond = $inf->{cond};
110 ! first { $_ !~ /^foreign\./ } (keys %$cond)
112 ! first { $_ !~ /^self\./ } (values %$cond)
114 for my $f (keys %$cond) {
116 $_ =~ s/^ (?: foreign | self ) \.//x for ($f, $s);
117 $relinfo->{$rel}{fk_map}{$s} = $f;
119 # need to know source from *our* pov, hence $rel.
120 $my_cols->{$s} ||= { via_fk => "$rel.$f" } if (
121 defined $rel_cols->{$rel}{$f} # in fact selected
123 $relinfo->{$rel}{is_inner}
129 # if the parent is already defined, assume all of its related FKs are selected
130 # (even if they in fact are NOT in the select list). Keep a record of what we
131 # assumed, and if any such phantom-column becomes part of our own collapser,
132 # throw everything assumed-from-parent away and replace with the collapser of
133 # the parent (whatever it may be)
134 my $assumed_from_parent;
135 unless ($parent_info->{underdefined}) {
136 $assumed_from_parent->{columns} = { map
137 # only add to the list if we do not already select said columns
138 { ! exists $my_cols->{$_} ? ( $_ => 1 ) : () }
139 values %{$parent_info->{rel_condition} || {}}
142 $my_cols->{$_} = { via_collapse => $parent_info->{collapse_on} }
143 for keys %{$assumed_from_parent->{columns}};
146 # get colinfo for everything
148 my $ci = $self->columns_info;
149 $my_cols->{$_}{colinfo} = $ci->{$_} for keys %$my_cols;
154 # try to resolve based on our columns (plus already inserted FK bridges)
158 my $idset = $self->_identifying_column_set ({map { $_ => $my_cols->{$_}{colinfo} } keys %$my_cols})
160 # see if the resulting collapser relies on any implied columns,
161 # and fix stuff up if this is the case
162 my @reduced_set = grep { ! $assumed_from_parent->{columns}{$_} } @$idset;
164 $collapse_map->{-node_id} = __unique_numlist(
165 (@reduced_set != @$idset) ? @{$parent_info->{collapse_on}} : (),
169 @{$rel_chain}[1 .. $#$rel_chain],
170 ( $my_cols->{$_}{via_fk} || $_ ),
180 # Stil don't know how to collapse - keep descending down 1:1 chains - if
181 # a related non-LEFT 1:1 is resolvable - its condition will collapse us
183 unless ($collapse_map->{-node_id}) {
186 for my $rel (keys %$relinfo) {
187 next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
189 if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse (
192 [ @$rel_chain, $rel ],
193 { underdefined => 1 }
195 push @candidates, $rel_collapse->{-node_id};
199 # get the set with least amount of columns
200 # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
201 # to a single varchar)
203 ($collapse_map->{-node_id}) = sort { scalar @$a <=> scalar @$b } (@candidates);
207 # Still dont know how to collapse - see if the parent passed us anything
208 # (i.e. reuse collapser over 1:1)
209 unless ($collapse_map->{-node_id}) {
210 $collapse_map->{-node_id} = $parent_info->{collapse_on}
211 if $parent_info->{collapser_reusable};
214 # stop descending into children if we were called by a parent for first-pass
215 # and don't despair if nothing was found (there may be other parallel branches
217 if ($parent_info->{underdefined}) {
218 return $collapse_map->{-node_id} ? $collapse_map : undef
220 # nothing down the chain resolved - can't calculate a collapse-map
221 elsif (! $collapse_map->{-node_id}) {
222 $self->throw_exception ( sprintf
223 "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
226 ? sprintf (' (last member of the %s chain)', join ' -> ', @$rel_chain )
232 # If we got that far - we are collapsable - GREAT! Now go down all children
233 # a second time, and fill in the rest
235 $collapse_map->{-is_optional} = 1 if $parent_info->{is_optional};
236 $collapse_map->{-node_index} = ${ $node_idx_ref ||= \do { my $x = 1 } }++; # this is *deliberately* not 0-based
238 my (@id_sets, $multis_in_chain);
239 for my $rel (sort keys %$relinfo) {
241 $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse (
242 { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
246 [ @$rel_chain, $rel],
249 collapse_on => [ @{$collapse_map->{-node_id}} ],
251 rel_condition => $relinfo->{$rel}{fk_map},
253 is_optional => $collapse_map->{-is_optional},
255 # if this is a 1:1 our own collapser can be used as a collapse-map
256 # (regardless of left or not)
257 collapser_reusable => $relinfo->{$rel}{is_single},
263 $collapse_map->{$rel}{-is_single} = 1 if $relinfo->{$rel}{is_single};
264 $collapse_map->{$rel}{-is_optional} ||= 1 unless $relinfo->{$rel}{is_inner};
265 push @id_sets, @{ $collapse_map->{$rel}{-branch_id} };
268 $collapse_map->{-branch_id} = __unique_numlist( @id_sets, @{$collapse_map->{-node_id}} );
270 return $collapse_map;
273 # Takes an arrayref of {as} dbic column aliases and the collapse and select
274 # attributes from the same $rs (the selector requirement is a temporary
275 # workaround... I hope), and returns a coderef capable of:
276 # my $me_pref_clps = $coderef->([$rs->cursor->next/all])
277 # Where the $me_pref_clps arrayref is the future argument to inflate_result()
279 # For an example of this coderef in action (and to see its guts) look at
280 # t/resultset/rowparser_internals.t
282 # This is a huge performance win, as we call the same code for # every row
283 # returned from the db, thus avoiding repeated method lookups when traversing
286 # Also since the coderef is completely stateless (the returned structure is
287 # always fresh on every new invocation) this is a very good opportunity for
288 # memoization if further speed improvements are needed
290 # The way we construct this coderef is somewhat fugly, although the result is
291 # really worth it. The final coderef does not perform any kind of recursion -
292 # the entire nested structure constructor is rolled out into a single scope.
294 # In any case - the output of this thing is meticulously micro-tested, so
295 # any sort of adjustment/rewrite should be relatively easy (fsvo relatively)
298 my ($self, $args) = @_;
300 my $inflate_index = { map
301 { $args->{inflate_map}[$_] => $_ }
302 ( 0 .. $#{$args->{inflate_map}} )
307 # the non-collapsing assembler is easy
308 # FIXME SUBOPTIMAL there could be a yet faster way to do things here, but
309 # need to try an actual implementation and benchmark it:
311 # <timbunce_> First setup the nested data structure you want for each row
312 # Then call bind_col() to alias the row fields into the right place in
313 # the data structure, then to fetch the data do:
314 # push @rows, dclone($row_data_struct) while ($sth->fetchrow);
316 if (!$args->{collapse}) {
317 $parser_src = sprintf('$_ = %s for @{$_[0]}', __visit_infmap_simple(
319 { rsrc => $self }, # need the $rsrc to sanity-check inflation map once
322 # change the quoted placeholders to unquoted alias-references
323 $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$_->[$1]"/gex;
326 # the collapsing parser is more complicated - it needs to keep a lot of state
330 my $collapse_map = $self->_resolve_collapse (
332 # only consider real columns (not functions) during collapse resolution
333 # this check shouldn't really be here, as fucktards are not supposed to
334 # alias random crap to existing column names anyway, but still - just in
336 # FIXME !!!! - this does not yet deal with unbalanced selectors correctly
337 # (it is now trivial as the attrs specify where things go out of sync
340 { ref $args->{selection}[$inflate_index->{$_}] ? () : ( $_ => $inflate_index->{$_} ) }
345 my $top_branch_idx_list = join (', ', @{$collapse_map->{-branch_id}});
347 my $top_node_id_path = join ('', map
348 { "{'\xFF__IDVALPOS__${_}__\xFF'}" }
349 @{$collapse_map->{-node_id}}
352 my $rel_assemblers = __visit_infmap_collapse (
353 $inflate_index, $collapse_map
356 $parser_src = sprintf (<<'EOS', $top_branch_idx_list, $top_node_id_path, $rel_assemblers);
357 ### BEGIN STRING EVAL
359 my ($rows_pos, $result_pos, $cur_row, @cur_row_ids, @collapse_idx, $is_new_res) = (0,0);
361 # this loop is a bit arcane - the rationale is that the passed in
362 # $_[0] will either have only one row (->next) or will have all
363 # rows already pulled in (->all and/or unordered). Given that the
364 # result can be rather large - we reuse the same already allocated
365 # array, since the collapsed prefetch is smaller by definition.
366 # At the end we cut the leftovers away and move on.
368 ( ( $rows_pos >= 0 and $_[0][$rows_pos++] ) or do { $rows_pos = -1; undef } )
370 ($_[1] and $_[1]->())
373 $cur_row_ids[$_] = defined $cur_row->[$_] ? $cur_row->[$_] : "\xFF\xFFN\xFFU\xFFL\xFFL\xFF\xFF"
374 for (%1$s); # the top branch_id includes all id values
376 $is_new_res = ! $collapse_idx[1]%2$s and (
377 $_[1] and $result_pos and (unshift @{$_[2]}, $cur_row) and last
382 $_[0][$result_pos++] = $collapse_idx[1]%2$s
386 splice @{$_[0]}, $result_pos; # truncate the passed in array for cases of collapsing ->all()
390 # !!! note - different var than the one above
391 # change the quoted placeholders to unquoted alias-references
392 $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$cur_row->[$1]"/gex;
393 $parser_src =~ s/ \' \xFF__IDVALPOS__(\d+)__\xFF \' /"\$cur_row_ids[$1]"/gex;
399 # the simple non-collapsing nested structure recursor
400 sub __visit_infmap_simple {
401 my ($val_idx, $args) = @_;
405 for (keys %$val_idx) {
406 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
407 $rel_cols->{$1}{$2} = $val_idx->{$_};
410 $my_cols->{$_} = $val_idx->{$_};
414 for my $rel (sort keys %$rel_cols) {
417 #my $optional = $args->{is_optional};
418 #$optional ||= ($args->{rsrc}->relationship_info($rel)->{attrs}{join_type} || '') =~ /^left/i;
420 push @relperl, join ' => ', perlstring($rel), __visit_infmap_simple($rel_cols->{$rel}, {
421 rsrc => __get_related_source($args->{rsrc}, $rel, $rel_cols->{$rel}),
424 #is_optional => $optional,
427 # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t
428 #if ($optional and my @branch_null_checks = map
429 # { "(! defined '\xFF__VALPOS__${_}__\xFF')" }
430 # sort { $a <=> $b } values %{$rel_cols->{$rel}}
432 # $relperl[-1] = sprintf ( '(%s) ? ( %s => [] ) : ( %s )',
433 # join (' && ', @branch_null_checks ),
440 my $me_struct = keys %$my_cols
441 ? __visit_dump({ map { $_ => "\xFF__VALPOS__$my_cols->{$_}__\xFF" } (keys %$my_cols) })
445 return sprintf '[%s]', join (',',
447 @relperl ? sprintf ('{ %s }', join (',', @relperl)) : (),
451 # the collapsing nested structure recursor
452 sub __visit_infmap_collapse {
454 my ($val_idx, $collapse_map, $parent_info) = @_;
458 for (keys %$val_idx) {
459 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
460 $rel_cols->{$1}{$2} = $val_idx->{$_};
463 $my_cols->{$_} = $val_idx->{$_};
467 my $sequenced_node_id = join ('', map
468 { "{'\xFF__IDVALPOS__${_}__\xFF'}" }
469 @{$collapse_map->{-node_id}}
472 my $me_struct = keys %$my_cols
473 ? __visit_dump([{ map { $_ => "\xFF__VALPOS__$my_cols->{$_}__\xFF" } (keys %$my_cols) }])
476 my $node_idx_ref = sprintf '$collapse_idx[%d]%s', $collapse_map->{-node_index}, $sequenced_node_id;
478 my $parent_idx_ref = sprintf( '$collapse_idx[%d]%s[1]{%s}',
479 @{$parent_info}{qw/node_idx sequenced_node_id/},
480 perlstring($parent_info->{relname}),
484 if ($collapse_map->{-node_index} == 1) {
485 push @src, sprintf( '%s ||= %s;',
490 elsif ($collapse_map->{-is_single}) {
491 push @src, sprintf ( '%s ||= %s%s;',
494 $me_struct ? " ||= $me_struct" : '',
498 push @src, sprintf('push @{%s}, %s%s unless %s;',
501 $me_struct ? " ||= $me_struct" : '',
507 #my $known_defined = { %{ $parent_info->{known_defined} || {} } };
508 #$known_defined->{$_}++ for @{$collapse_map->{-node_id}};
510 for my $rel (sort keys %$rel_cols) {
512 push @src, sprintf( '%s[1]{%s} ||= [];', $node_idx_ref, perlstring($rel) )
513 unless $collapse_map->{$rel}{-is_single};
515 push @src, __visit_infmap_collapse($rel_cols->{$rel}, $collapse_map->{$rel}, {
516 node_idx => $collapse_map->{-node_index},
517 sequenced_node_id => $sequenced_node_id,
520 #known_defined => $known_defined,
523 # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t
524 #if ($collapse_map->{$rel}{-is_optional} and my @null_checks = map
525 # { "(! defined '\xFF__IDVALPOS__${_}__\xFF')" }
526 # sort { $a <=> $b } grep
527 # { ! $known_defined->{$_} }
528 # @{$collapse_map->{$rel}{-node_id}}
530 # $src[-1] = sprintf( '(%s) or %s',
531 # join (' || ', @null_checks ),
540 # adding a dep on MoreUtils *just* for this is retarded
541 sub __unique_numlist {
542 [ sort { $a <=> $b } keys %{ {map { $_ => 1 } @_ }} ]
545 # This error must be thrown from two distinct codepaths, joining them is
546 # rather hard. Go for this hack instead.
547 sub __get_related_source {
548 my ($rsrc, $rel, $relcols) = @_;
550 $rsrc->related_source ($rel)
552 $rsrc->throw_exception(sprintf(
553 "Can't inflate prefetch into non-existent relationship '%s' from '%s', "
554 . "check the inflation specification (columns/as) ending in '...%s.%s'.",
558 (sort { length($a) <=> length ($b) } keys %$relcols)[0],
562 # keep our own DD object around so we don't have to fitz with quoting
565 # we actually will be producing functional perl code here,
566 # thus no second-guessing of what these globals might have
567 # been set to. DO NOT CHANGE!
568 ($dumper_obj ||= do {
569 require Data::Dumper;
570 Data::Dumper->new([])
580 ->Indent (0) # faster but harder to read, perhaps leave at 1 ?
581 })->Values ([$_[0]])->Dump;