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
14 use DBIx::Class::Carp;
18 # Accepts a prefetch map (one or more relationships for the current source),
19 # returns a set of select/as pairs for each of those relationships. Columns
20 # are fully qualified inflation_slot names
21 sub _resolve_selection_from_prefetch {
22 my ($self, $pre, $alias_map, $pref_path) = @_;
24 # internal recursion marker
27 if (not defined $pre or not length $pre) {
30 elsif( ref $pre eq 'ARRAY' ) {
31 map { $self->_resolve_selection_from_prefetch( $_, $alias_map, [ @$pref_path ] ) }
34 elsif( ref $pre eq 'HASH' ) {
36 $self->_resolve_selection_from_prefetch($_, $alias_map, [ @$pref_path ] ),
37 $self->related_source($_)->_resolve_selection_from_prefetch(
38 $pre->{$_}, $alias_map, [ @$pref_path, $_] )
42 $self->throw_exception(
43 "don't know how to resolve prefetch reftype ".ref($pre));
47 $p = $p->{$_} for @$pref_path, $pre;
49 $self->throw_exception (
50 "Unable to resolve prefetch '$pre' - join alias map does not contain an entry for path: "
51 . join (' -> ', @$pref_path, $pre)
52 ) if (ref $p->{-join_aliases} ne 'ARRAY' or not @{$p->{-join_aliases}} );
54 # this shift() is critical - it is what allows prefetch => [ (foo) x 2 ] to work
55 my $src_alias = shift @{$p->{-join_aliases}};
57 # ordered [select => as] pairs
59 "${src_alias}.$_" => join ( '.',
64 ] } $self->related_source($pre)->columns;
68 sub _resolve_prefetch {
70 'There is no good reason to call this internal deprecated method - '
71 . 'please open a ticket detailing your usage, so that a better plan can '
72 . 'be devised for your case. In either case _resolve_prefetch() is '
73 . 'deprecated in favor of _resolve_selection_from_prefetch(), which has '
74 . 'a greatly simplified arglist.'
77 $_[0]->_resolve_selection_from_prefetch( $_[1], $_[3] );
81 # Takes an arrayref of {as} dbic column aliases and the collapse and select
82 # attributes from the same $rs (the selector requirement is a temporary
83 # workaround... I hope), and returns a coderef capable of:
84 # my $me_pref_clps = $coderef->([$rs->cursor->next/all])
85 # Where the $me_pref_clps arrayref is the future argument to inflate_result()
87 # For an example of this coderef in action (and to see its guts) look at
88 # t/resultset/rowparser_internals.t
90 # This is a huge performance win, as we call the same code for every row
91 # returned from the db, thus avoiding repeated method lookups when traversing
94 # Also since the coderef is completely stateless (the returned structure is
95 # always fresh on every new invocation) this is a very good opportunity for
96 # memoization if further speed improvements are needed
98 # The way we construct this coderef is somewhat fugly, although the result is
99 # really worth it. The final coderef does not perform any kind of recursion -
100 # the entire nested structure constructor is rolled out into a single scope.
102 # In any case - the output of this thing is meticulously micro-tested, so
103 # any sort of adjustment/rewrite should be relatively easy (fsvo relatively)
106 # $args and $attrs are separated to delineate what is core collapser stuff and
107 # what is dbic $rs specific
108 my ($self, $args, $attrs) = @_;
110 die "HRI without pruning makes zero sense"
111 if ( $args->{hri_style} && ! $args->{prune_null_branches} );
114 hri_style => $args->{hri_style},
115 prune_null_branches => $args->{prune_null_branches},
117 { $args->{inflate_map}[$_] => $_ }
118 ( 0 .. $#{$args->{inflate_map}} )
122 my $src = (! $args->{collapse} ) ? assemble_simple_parser(\%common) : do {
123 my $collapse_map = $self->_resolve_collapse ({
125 # only consider real columns (not functions) during collapse resolution
126 # this check shouldn't really be here, as fucktards are not supposed to
127 # alias random crap to existing column names anyway, but still - just in
129 # FIXME !!!! - this does not yet deal with unbalanced selectors correctly
130 # (it is now trivial as the attrs specify where things go out of sync
133 { ref $attrs->{select}[$common{val_index}{$_}] ? () : ( $_ => $common{val_index}{$_} ) }
134 keys %{$common{val_index}}
136 premultiplied => $args->{premultiplied},
139 assemble_collapsing_parser({
141 collapse_map => $collapse_map,
146 if DBIx::Class::_ENV_::STRESSTEST_UTF8_UPGRADE_GENERATED_COLLAPSER_SOURCE;
152 # Takes an arrayref selection list and generates a collapse-map representing
153 # row-object fold-points. Every relationship is assigned a set of unique,
154 # non-nullable columns (which may *not even be* from the same resultset)
155 # and the collapser will use this information to correctly distinguish
156 # data of individual to-be-row-objects. See t/resultset/rowparser_internals.t
157 # for extensive RV examples
158 sub _resolve_collapse {
159 my ($self, $args, $common_args) = @_;
161 # for comprehensible error messages put ourselves at the head of the relationship chain
162 $args->{_rel_chain} ||= [ $self->source_name ];
164 # record top-level fully-qualified column index, signify toplevelness
165 unless ($common_args->{_as_fq_idx}) {
166 $common_args->{_as_fq_idx} = { %{$args->{as}} };
167 $args->{_is_top_level} = 1;
170 my ($my_cols, $rel_cols, $native_cols);
171 for (keys %{$args->{as}}) {
172 if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
173 $rel_cols->{$1}{$2} = 1;
176 $native_cols->{$_} = $my_cols->{$_} = {}; # important for ||='s below
181 # run through relationships, collect metadata
182 for my $rel (keys %$rel_cols) {
183 my $inf = $self->relationship_info ($rel);
186 is_single => ( $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi' ),
187 is_inner => ( ( $inf->{attrs}{join_type} || '' ) !~ /^left/i),
188 rsrc => $self->related_source($rel),
189 fk_map => $self->_resolve_relationship_condition(
191 self_alias => "\xFE", # irrelevant
192 foreign_alias => "\xFF", # irrelevant
197 # inject non-left fk-bridges from *INNER-JOINED* children (if any)
198 for my $rel (grep { $relinfo->{$_}{is_inner} } keys %$relinfo) {
199 my $ri = $relinfo->{$rel};
200 for (keys %{$ri->{fk_map}} ) {
201 # need to know source from *our* pov, hence $rel.col
202 $my_cols->{$_} ||= { via_fk => "$rel.$ri->{fk_map}{$_}" }
203 if defined $rel_cols->{$rel}{$ri->{fk_map}{$_}} # in fact selected
207 # if the parent is already defined *AND* we have an inner reverse relationship
208 # (i.e. do not exist without it) , assume all of its related FKs are selected
209 # (even if they in fact are NOT in the select list). Keep a record of what we
210 # assumed, and if any such phantom-column becomes part of our own collapser,
211 # throw everything assumed-from-parent away and replace with the collapser of
212 # the parent (whatever it may be)
213 my $assumed_from_parent;
214 if ( ! $args->{_parent_info}{underdefined} and ! $args->{_parent_info}{rev_rel_is_optional} ) {
215 for my $col ( values %{$args->{_parent_info}{rel_condition} || {}} ) {
216 next if exists $my_cols->{$col};
217 $my_cols->{$col} = {};
218 $assumed_from_parent->{columns}{$col}++;
222 # get colinfo for everything
224 my $ci = $self->columns_info;
225 $my_cols->{$_}{colinfo} = $ci->{$_} for keys %$my_cols;
230 # first try to reuse the parent's collapser (i.e. reuse collapser over 1:1)
231 # (makes for a leaner coderef later)
233 ! $collapse_map->{-identifying_columns}
235 $args->{_parent_info}{collapser_reusable}
237 $collapse_map->{-identifying_columns} = $args->{_parent_info}{collapse_on_idcols}
240 # Still don't know how to collapse - in case we are a *single* relationship
241 # AND our parent is defined AND we have any *native* non-nullable pieces: then
242 # we are still good to go
243 # NOTE: it doesn't matter if the nonnullable set is unique or not - it will be
244 # made unique by the parents identifying cols
246 ! $collapse_map->{-identifying_columns}
248 $args->{_parent_info}{is_single}
250 @{ $args->{_parent_info}{collapse_on_idcols} }
252 ( my @native_nonnull_cols = grep {
253 $native_cols->{$_}{colinfo}
255 ! $native_cols->{$_}{colinfo}{is_nullable}
256 } keys %$native_cols )
259 $collapse_map->{-identifying_columns} = [ __unique_numlist(
260 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
262 # FIXME - we don't really need *all* of the columns, $our_nonnull_cols[0]
263 # is sufficient. However map the entire thing to engage the extra nonnull
264 # explicit checks, just to be on the safe side
265 # Remove some day in the future
268 $common_args->{_as_fq_idx}{join ('.',
269 @{$args->{_rel_chain}}[1 .. $#{$args->{_rel_chain}}],
278 # Still don't know how to collapse - try to resolve based on our columns (plus already inserted FK bridges)
280 ! $collapse_map->{-identifying_columns}
284 my $idset = $self->_identifying_column_set ({map { $_ => $my_cols->{$_}{colinfo} } keys %$my_cols})
286 # see if the resulting collapser relies on any implied columns,
287 # and fix stuff up if this is the case
288 my @reduced_set = grep { ! $assumed_from_parent->{columns}{$_} } @$idset;
290 $collapse_map->{-identifying_columns} = [ __unique_numlist(
291 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
296 @{$args->{_rel_chain}}[1 .. $#{$args->{_rel_chain}}],
297 ( $my_cols->{$_}{via_fk} || $_ ),
300 $common_args->{_as_fq_idx}->{$fqc};
307 # Stil don't know how to collapse - keep descending down 1:1 chains - if
308 # a related non-LEFT 1:1 is resolvable - its condition will collapse us
310 unless ($collapse_map->{-identifying_columns}) {
313 for my $rel (keys %$relinfo) {
314 next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
316 if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
317 as => $rel_cols->{$rel},
318 _rel_chain => [ @{$args->{_rel_chain}}, $rel ],
319 _parent_info => { underdefined => 1 },
321 push @candidates, $rel_collapse->{-identifying_columns};
325 # get the set with least amount of columns
326 # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
327 # to a single varchar)
329 ($collapse_map->{-identifying_columns}) = sort { scalar @$a <=> scalar @$b } (@candidates);
333 # Stil don't know how to collapse, and we are the root node. Last ditch
334 # effort in case we are *NOT* premultiplied.
335 # Run through *each multi* all the way down, left or not, and all
336 # *left* singles (a single may become a multi underneath) . When everything
337 # gets back see if all the rels link to us definitively. If this is the
338 # case we are good - either one of them will define us, or if all are NULLs
339 # we know we are "unique" due to the "non-premultiplied" check
341 ! $collapse_map->{-identifying_columns}
343 ! $args->{premultiplied}
345 $args->{_is_top_level}
347 my (@collapse_sets, $uncollapsible_chain);
349 for my $rel (keys %$relinfo) {
351 # we already looked at these higher up
352 next if ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
354 if (my $clps = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
355 as => $rel_cols->{$rel},
356 _rel_chain => [ @{$args->{_rel_chain}}, $rel ],
357 _parent_info => { underdefined => 1 },
360 # for singles use the idcols wholesale (either there or not)
361 if ($relinfo->{$rel}{is_single}) {
362 push @collapse_sets, $clps->{-identifying_columns};
364 elsif (! $relinfo->{$rel}{fk_map}) {
365 $uncollapsible_chain = 1;
369 my $defined_cols_parent_side;
371 for my $fq_col ( grep { /^$rel\.[^\.]+$/ } keys %{$args->{as}} ) {
372 my ($col) = $fq_col =~ /([^\.]+)$/;
374 $defined_cols_parent_side->{$_} = $args->{as}{$fq_col} for grep
375 { $relinfo->{$rel}{fk_map}{$_} eq $col }
376 keys %{$relinfo->{$rel}{fk_map}}
380 if (my $set = $self->_identifying_column_set([ keys %$defined_cols_parent_side ]) ) {
381 push @collapse_sets, [ sort map { $defined_cols_parent_side->{$_} } @$set ];
384 $uncollapsible_chain = 1;
390 $uncollapsible_chain = 1;
395 unless ($uncollapsible_chain) {
396 # if we got here - we are good to go, but the construction is tricky
397 # since our children will want to include our collapse criteria - we
398 # don't give them anything (safe, since they are all collapsible on their own)
399 # in addition we record the individual collapse possibilities
400 # of all left children node collapsers, and merge them in the rowparser
402 $collapse_map->{-identifying_columns} = [];
403 $collapse_map->{-identifying_columns_variants} = [ sort {
404 (scalar @$a) <=> (scalar @$b)
408 ( sort { $b <=> $a } @$a )[0]
410 ( sort { $b <=> $a } @$b )[0]
416 # stop descending into children if we were called by a parent for first-pass
417 # and don't despair if nothing was found (there may be other parallel branches
419 if ($args->{_parent_info}{underdefined}) {
420 return $collapse_map->{-identifying_columns} ? $collapse_map : undef
422 # nothing down the chain resolved - can't calculate a collapse-map
423 elsif (! $collapse_map->{-identifying_columns}) {
424 $self->throw_exception ( sprintf
425 "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
427 @{$args->{_rel_chain}} > 1
428 ? sprintf (' (last member of the %s chain)', join ' -> ', @{$args->{_rel_chain}} )
434 # If we got that far - we are collapsable - GREAT! Now go down all children
435 # a second time, and fill in the rest
437 $collapse_map->{-identifying_columns} = [ __unique_numlist(
438 @{ $args->{_parent_info}{collapse_on_idcols}||[] },
439 @{ $collapse_map->{-identifying_columns} },
442 for my $rel (sort keys %$relinfo) {
444 $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse ({
445 as => { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
446 _rel_chain => [ @{$args->{_rel_chain}}, $rel],
449 collapse_on_idcols => [ @{$collapse_map->{-identifying_columns}} ],
451 rel_condition => $relinfo->{$rel}{fk_map},
453 is_optional => ! $relinfo->{$rel}{is_inner},
455 is_single => $relinfo->{$rel}{is_single},
457 # if there is at least one *inner* reverse relationship which is HASH-based (equality only)
458 # we can safely assume that the child can not exist without us
459 rev_rel_is_optional => ( grep
460 { ref $_->{cond} eq 'HASH' and ($_->{attrs}{join_type}||'') !~ /^left/i }
461 values %{ $self->reverse_relationship_info($rel) },
464 # if this is a 1:1 our own collapser can be used as a collapse-map
465 # (regardless of left or not)
466 collapser_reusable => (
467 $relinfo->{$rel}{is_single}
469 $relinfo->{$rel}{is_inner}
471 @{$collapse_map->{-identifying_columns}}
476 $collapse_map->{$rel}{-is_single} = 1 if $relinfo->{$rel}{is_single};
477 $collapse_map->{$rel}{-is_optional} ||= 1 unless $relinfo->{$rel}{is_inner};
480 return $collapse_map;
483 # adding a dep on MoreUtils *just* for this is retarded
484 sub __unique_numlist {
485 sort { $a <=> $b } keys %{ {map { $_ => 1 } @_ }}