1 package # hide from the pauses
2 DBIx::Class::ResultSource::RowParser;
7 use base 'DBIx::Class';
9 use DBIx::Class::ResultSource::RowParser::Util qw(
10 assemble_simple_parser
11 assemble_collapsing_parser
13 use DBIx::Class::_Util qw( DUMMY_ALIASPAIR dbic_internal_try dbic_internal_catch );
15 use DBIx::Class::Carp;
17 # FIXME - this should go away
18 # instead Carp::Skip should export usable keywords or something like that
20 BEGIN { $unique_carper = \&carp_unique }
24 # Accepts a prefetch map (one or more relationships for the current source),
25 # returns a set of select/as pairs for each of those relationships. Columns
26 # are fully qualified inflation_slot names
27 sub _resolve_selection_from_prefetch {
28 my ($self, $pre, $alias_map, $pref_path) = @_;
30 # internal recursion marker
33 if (not defined $pre or not length $pre) {
36 elsif( ref $pre eq 'ARRAY' ) {
37 map { $self->_resolve_selection_from_prefetch( $_, $alias_map, [ @$pref_path ] ) }
40 elsif( ref $pre eq 'HASH' ) {
42 $self->_resolve_selection_from_prefetch($_, $alias_map, [ @$pref_path ] ),
43 $self->related_source($_)->_resolve_selection_from_prefetch(
44 $pre->{$_}, $alias_map, [ @$pref_path, $_] )
48 $self->throw_exception(
49 "don't know how to resolve prefetch reftype ".ref($pre));
53 $p = $p->{$_} for @$pref_path, $pre;
55 $self->throw_exception (
56 "Unable to resolve prefetch '$pre' - join alias map does not contain an entry for path: "
57 . join (' -> ', @$pref_path, $pre)
58 ) if (ref $p->{-join_aliases} ne 'ARRAY' or not @{$p->{-join_aliases}} );
60 # this shift() is critical - it is what allows prefetch => [ (foo) x 2 ] to work
61 my $src_alias = shift @{$p->{-join_aliases}};
63 # ordered [select => as] pairs
65 "${src_alias}.$_" => join ( '.',
70 ] } $self->related_source($pre)->columns;
74 sub _resolve_prefetch {
76 'There is no good reason to call this internal deprecated method - '
77 . 'please open a ticket detailing your usage, so that a better plan can '
78 . 'be devised for your case. In either case _resolve_prefetch() is '
79 . 'deprecated in favor of _resolve_selection_from_prefetch(), which has '
80 . 'a greatly simplified arglist.'
83 $_[0]->_resolve_selection_from_prefetch( $_[1], $_[3] );
87 # Takes an arrayref of {as} dbic column aliases and the collapse and select
88 # attributes from the same $rs (the selector requirement is a temporary
89 # workaround... I hope), and returns a coderef capable of:
90 # my $me_pref_clps = $coderef->([$rs->cursor->next/all])
91 # Where the $me_pref_clps arrayref is the future argument to inflate_result()
93 # For an example of this coderef in action (and to see its guts) look at
94 # t/resultset/rowparser_internals.t
96 # This is a huge performance win, as we call the same code for every row
97 # returned from the db, thus avoiding repeated method lookups when traversing
100 # Also since the coderef is completely stateless (the returned structure is
101 # always fresh on every new invocation) this is a very good opportunity for
102 # memoization if further speed improvements are needed
104 # The way we construct this coderef is somewhat fugly, although the result is
105 # really worth it. The final coderef does not perform any kind of recursion -
106 # the entire nested structure constructor is rolled out into a single scope.
108 # In any case - the output of this thing is meticulously micro-tested, so
109 # any sort of adjustment/rewrite should be relatively easy (fsvo relatively)
112 # $args and $attrs are separated to delineate what is core collapser stuff and
113 # what is dbic $rs specific
114 my ($self, $args, $attrs) = @_;
116 die "HRI without pruning makes zero sense"
117 if ( $args->{hri_style} && ! $args->{prune_null_branches} );
120 hri_style => $args->{hri_style},
121 prune_null_branches => $args->{prune_null_branches},
123 { $args->{inflate_map}[$_] => $_ }
124 ( 0 .. $#{$args->{inflate_map}} )
128 my $src = (! $args->{collapse} ) ? assemble_simple_parser(\%common) : do {
129 my $collapse_map = $self->_resolve_collapse ({
131 # only consider real columns (not functions) during collapse resolution
132 # this check shouldn't really be here, as fucktards are not supposed to
133 # alias random crap to existing column names anyway, but still - just in
135 # FIXME !!!! - this does not yet deal with unbalanced selectors correctly
136 # (it is now trivial as the attrs specify where things go out of sync
139 { ref $attrs->{select}[$common{val_index}{$_}] ? () : ( $_ => $common{val_index}{$_} ) }
140 keys %{$common{val_index}}
142 premultiplied => $args->{premultiplied},
145 assemble_collapsing_parser({
147 collapse_map => $collapse_map,
152 if DBIx::Class::_ENV_::STRESSTEST_UTF8_UPGRADE_GENERATED_COLLAPSER_SOURCE;
158 # Takes an arrayref selection list and generates a collapse-map representing
159 # row-object fold-points. Every relationship is assigned a set of unique,
160 # non-nullable columns (which may *not even be* from the same resultset)
161 # and the collapser will use this information to correctly distinguish
162 # data of individual to-be-row-objects. See t/resultset/rowparser_internals.t
163 # for extensive RV examples
164 sub _resolve_collapse {
165 my ($self, $args, $common_args) = @_;
167 # for comprehensible error messages put ourselves at the head of the relationship chain
168 $args->{_rel_chain} ||= [ $self->source_name ];
170 # record top-level fully-qualified column index, signify toplevelness
171 unless ($common_args->{_as_fq_idx}) {
172 $common_args->{_as_fq_idx} = { %{$args->{as}} };
173 $args->{_is_top_level} = 1;
176 my ($my_cols, $rel_cols, $native_cols);
177 for (keys %{$args->{as}}) {
178 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
179 $rel_cols->{$1}{$2} = 1;
182 $native_cols->{$_} = $my_cols->{$_} = {}; # important for ||='s below
187 # run through relationships, collect metadata
188 for my $rel (keys %$rel_cols) {
189 my $inf = $self->relationship_info ($rel);
192 is_single => ( $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi' ),
193 is_inner => ( ( $inf->{attrs}{join_type} || '' ) !~ /^left/i),
194 rsrc => $self->related_source($rel),
197 $self->resolve_relationship_condition(
200 # an API where these are optional would be too cumbersome,
201 # instead always pass in some dummy values
205 dbic_internal_catch {
208 "Resolution of relationship '$rel' failed unexpectedly, "
209 . 'please relay the following error and seek assistance via '
210 . DBIx::Class::_ENV_::HELP_URL . ". Encountered error: $_"
220 # inject non-left fk-bridges from *INNER-JOINED* children (if any)
221 for my $rel (grep { $relinfo->{$_}{is_inner} } keys %$relinfo) {
222 my $ri = $relinfo->{$rel};
223 for (keys %{$ri->{fk_map}} ) {
224 # need to know source from *our* pov, hence $rel.col
225 $my_cols->{$_} ||= { via_fk => "$rel.$ri->{fk_map}{$_}" }
226 if defined $rel_cols->{$rel}{$ri->{fk_map}{$_}} # in fact selected
230 # if the parent is already defined *AND* we have an inner reverse relationship
231 # (i.e. do not exist without it) , assume all of its related FKs are selected
232 # (even if they in fact are NOT in the select list). Keep a record of what we
233 # assumed, and if any such phantom-column becomes part of our own collapser,
234 # throw everything assumed-from-parent away and replace with the collapser of
235 # the parent (whatever it may be)
236 my $assumed_from_parent;
237 if ( ! $args->{_parent_info}{underdefined} and ! $args->{_parent_info}{rev_rel_is_optional} ) {
238 for my $col ( values %{$args->{_parent_info}{rel_condition} || {}} ) {
239 next if exists $my_cols->{$col};
240 $my_cols->{$col} = {};
241 $assumed_from_parent->{columns}{$col}++;
245 # get colinfo for everything
247 my $ci = $self->columns_info;
248 $my_cols->{$_}{colinfo} = $ci->{$_} for keys %$my_cols;
253 # first try to reuse the parent's collapser (i.e. reuse collapser over 1:1)
254 # (makes for a leaner coderef later)
256 ! $collapse_map->{-identifying_columns}
258 $args->{_parent_info}{collapser_reusable}
260 $collapse_map->{-identifying_columns} = $args->{_parent_info}{collapse_on_idcols}
263 # Still don't know how to collapse - in case we are a *single* relationship
264 # AND our parent is defined AND we have any *native* non-nullable pieces: then
265 # we are still good to go
266 # NOTE: it doesn't matter if the nonnullable set is unique or not - it will be
267 # made unique by the parents identifying cols
269 ! $collapse_map->{-identifying_columns}
271 $args->{_parent_info}{is_single}
273 @{ $args->{_parent_info}{collapse_on_idcols} }
275 ( my @native_nonnull_cols = grep {
276 $native_cols->{$_}{colinfo}
278 ! $native_cols->{$_}{colinfo}{is_nullable}
279 } keys %$native_cols )
282 $collapse_map->{-identifying_columns} = [ __unique_numlist(
283 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
285 # FIXME - we don't really need *all* of the columns, $our_nonnull_cols[0]
286 # is sufficient. However map the entire thing to engage the extra nonnull
287 # explicit checks, just to be on the safe side
288 # Remove some day in the future
291 $common_args->{_as_fq_idx}{join ('.',
292 @{$args->{_rel_chain}}[1 .. $#{$args->{_rel_chain}}],
301 # Still don't know how to collapse - try to resolve based on our columns (plus already inserted FK bridges)
303 ! $collapse_map->{-identifying_columns}
307 my $idset = $self->_identifying_column_set ({map { $_ => $my_cols->{$_}{colinfo} } keys %$my_cols})
309 # see if the resulting collapser relies on any implied columns,
310 # and fix stuff up if this is the case
311 my @reduced_set = grep { ! $assumed_from_parent->{columns}{$_} } @$idset;
313 $collapse_map->{-identifying_columns} = [ __unique_numlist(
314 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
319 @{$args->{_rel_chain}}[1 .. $#{$args->{_rel_chain}}],
320 ( $my_cols->{$_}{via_fk} || $_ ),
323 $common_args->{_as_fq_idx}->{$fqc};
330 # Stil don't know how to collapse - keep descending down 1:1 chains - if
331 # a related non-LEFT 1:1 is resolvable - its condition will collapse us
333 unless ($collapse_map->{-identifying_columns}) {
336 for my $rel (keys %$relinfo) {
337 next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
339 if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
340 as => $rel_cols->{$rel},
341 _rel_chain => [ @{$args->{_rel_chain}}, $rel ],
342 _parent_info => { underdefined => 1 },
344 push @candidates, $rel_collapse->{-identifying_columns};
348 # get the set with least amount of columns
349 # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
350 # to a single varchar)
352 ($collapse_map->{-identifying_columns}) = sort { scalar @$a <=> scalar @$b } (@candidates);
356 # Stil don't know how to collapse, and we are the root node. Last ditch
357 # effort in case we are *NOT* premultiplied.
358 # Run through *each multi* all the way down, left or not, and all
359 # *left* singles (a single may become a multi underneath) . When everything
360 # gets back see if all the rels link to us definitively. If this is the
361 # case we are good - either one of them will define us, or if all are NULLs
362 # we know we are "unique" due to the "non-premultiplied" check
364 ! $collapse_map->{-identifying_columns}
366 ! $args->{premultiplied}
368 $args->{_is_top_level}
370 my (@collapse_sets, $uncollapsible_chain);
372 for my $rel (keys %$relinfo) {
374 # we already looked at these higher up
375 next if ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
377 if (my $clps = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
378 as => $rel_cols->{$rel},
379 _rel_chain => [ @{$args->{_rel_chain}}, $rel ],
380 _parent_info => { underdefined => 1 },
383 # for singles use the idcols wholesale (either there or not)
384 if ($relinfo->{$rel}{is_single}) {
385 push @collapse_sets, $clps->{-identifying_columns};
387 elsif (! $relinfo->{$rel}{fk_map}) {
388 $uncollapsible_chain = 1;
392 my $defined_cols_parent_side;
394 for my $fq_col ( grep { /^$rel\.[^\.]+$/ } keys %{$args->{as}} ) {
395 my ($col) = $fq_col =~ /([^\.]+)$/;
397 $defined_cols_parent_side->{$_} = $args->{as}{$fq_col} for grep
398 { $relinfo->{$rel}{fk_map}{$_} eq $col }
399 keys %{$relinfo->{$rel}{fk_map}}
403 if (my $set = $self->_identifying_column_set([ keys %$defined_cols_parent_side ]) ) {
404 push @collapse_sets, [ sort map { $defined_cols_parent_side->{$_} } @$set ];
407 $uncollapsible_chain = 1;
413 $uncollapsible_chain = 1;
418 unless ($uncollapsible_chain) {
419 # if we got here - we are good to go, but the construction is tricky
420 # since our children will want to include our collapse criteria - we
421 # don't give them anything (safe, since they are all collapsible on their own)
422 # in addition we record the individual collapse possibilities
423 # of all left children node collapsers, and merge them in the rowparser
425 $collapse_map->{-identifying_columns} = [];
426 $collapse_map->{-identifying_columns_variants} = [ sort {
427 (scalar @$a) <=> (scalar @$b)
431 ( sort { $b <=> $a } @$a )[0]
433 ( sort { $b <=> $a } @$b )[0]
439 # stop descending into children if we were called by a parent for first-pass
440 # and don't despair if nothing was found (there may be other parallel branches
442 if ($args->{_parent_info}{underdefined}) {
443 return $collapse_map->{-identifying_columns} ? $collapse_map : undef
445 # nothing down the chain resolved - can't calculate a collapse-map
446 elsif (! $collapse_map->{-identifying_columns}) {
447 $self->throw_exception ( sprintf
448 "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
450 @{$args->{_rel_chain}} > 1
451 ? sprintf (' (last member of the %s chain)', join ' -> ', @{$args->{_rel_chain}} )
457 # If we got that far - we are collapsable - GREAT! Now go down all children
458 # a second time, and fill in the rest
460 $collapse_map->{-identifying_columns} = [ __unique_numlist(
461 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
462 @{ $collapse_map->{-identifying_columns} },
465 for my $rel (sort keys %$relinfo) {
467 $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
468 as => { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
469 _rel_chain => [ @{$args->{_rel_chain}}, $rel],
472 collapse_on_idcols => [ @{$collapse_map->{-identifying_columns}} ],
474 rel_condition => $relinfo->{$rel}{fk_map},
476 is_optional => ! $relinfo->{$rel}{is_inner},
478 is_single => $relinfo->{$rel}{is_single},
480 # if there is at least one *inner* reverse relationship ( meaning identity-only )
481 # we can safely assume that the child can not exist without us
482 rev_rel_is_optional => (
484 ($_->{attrs}{join_type}||'') !~ /^left/i
485 } values %{ $self->reverse_relationship_info($rel) } )
490 # if this is a 1:1 our own collapser can be used as a collapse-map
491 # (regardless of left or not)
492 collapser_reusable => (
493 $relinfo->{$rel}{is_single}
495 $relinfo->{$rel}{is_inner}
497 @{$collapse_map->{-identifying_columns}}
502 $collapse_map->{$rel}{-is_single} = 1 if $relinfo->{$rel}{is_single};
503 $collapse_map->{$rel}{-is_optional} ||= 1 unless $relinfo->{$rel}{is_inner};
506 return $collapse_map;
509 # adding a dep on MoreUtils *just* for this is retarded
510 sub __unique_numlist {
511 sort { $a <=> $b } keys %{ {map { $_ => 1 } @_ }}