return @new;
}
-sub _collapse_result {
- my ($self, $as_proto, $row) = @_;
-
- # if the first row that ever came in is totally empty - this means we got
- # hit by a smooth^Wempty left-joined resultset. Just noop in that case
- # instead of producing a {}
- #
- my $has_def;
- for (@$row) {
- if (defined $_) {
- $has_def++;
- last;
+# _unflatten_result takes a row hashref which looks like this:
+# $VAR1 = {
+# 'cd.artist.artistid' => '1',
+# 'cd.artist' => '1',
+# 'cd_id' => '1',
+# 'cd.genreid' => undef,
+# 'cd.year' => '1999',
+# 'cd.title' => 'Spoonful of bees',
+# 'cd.single_track' => undef,
+# 'cd.artist.name' => 'Caterwauler McCrae',
+# 'cd.artist.rank' => '13',
+# 'cd.artist.charfield' => undef,
+# 'cd.cdid' => '1'
+# };
+
+# and generates the following structure:
+
+# $VAR1 = [
+# {
+# 'cd_id' => '1'
+# },
+# {
+# 'cd' => [
+# {
+# 'single_track' => undef,
+# 'cdid' => '1',
+# 'artist' => '1',
+# 'title' => 'Spoonful of bees',
+# 'year' => '1999',
+# 'genreid' => undef
+# },
+# {
+# 'artist' => [
+# {
+# 'artistid' => '1',
+# 'charfield' => undef,
+# 'name' => 'Caterwauler McCrae',
+# 'rank' => '13'
+# }
+# ]
+# }
+# ]
+# }
+# ];
+
+# It returns one row object which consists of an arrayref with two
+# elements. The first contains the plain column data, the second
+# contains the data of relationships. Those are row arrayrefs, themselves.
+
+# it's a recursive function. It needs to request the relationship_info
+# to decide whether to put the data of a relationship in a hashref
+# (i.e. belongs_to) or an arrayref (i.e. has_many).
+
+sub _unflatten_result {
+ my ( $self, $row ) = @_;
+
+ my $columns = {};
+ my $rels = {};
+
+ foreach my $column ( sort keys %$row ) {
+ if ( $column =~ /^(.*?)\.(.*)$/ ) {
+ $rels->{$1} ||= {};
+ $rels->{$1}->{$2} = $row->{$column};
+ }
+ else {
+ $columns->{$column} = $row->{$column};
+ }
}
- }
- return undef unless $has_def;
-
- my @copy = @$row;
-
- # 'foo' => [ undef, 'foo' ]
- # 'foo.bar' => [ 'foo', 'bar' ]
- # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
-
- my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
-
- my %collapse = %{$self->{_attrs}{collapse}||{}};
-
- my @pri_index;
- # if we're doing collapsing (has_many prefetch) we need to grab records
- # until the PK changes, so fill @pri_index. if not, we leave it empty so
- # we know we don't have to bother.
-
- # the reason for not using the collapse stuff directly is because if you
- # had for e.g. two artists in a row with no cds, the collapse info for
- # both would be NULL (undef) so you'd lose the second artist
-
- # store just the index so we can check the array positions from the row
- # without having to contruct the full hash
-
- if (keys %collapse) {
- my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
- foreach my $i (0 .. $#construct_as) {
- next if defined($construct_as[$i][0]); # only self table
- if (delete $pri{$construct_as[$i][1]}) {
- push(@pri_index, $i);
- }
- last unless keys %pri; # short circuit (Johnny Five Is Alive!)
+ foreach my $rel ( sort keys %$rels ) {
+ my $rel_info = $self->result_source->relationship_info($rel);
+ $rels->{$rel} =
+ $self->related_resultset($rel)->_unflatten_result( $rels->{$rel} );
+ $rels->{$rel} = [ $rels->{$rel} ]
+ if ( $rel_info->{attrs}->{accessor} eq 'multi' );
}
- }
-
- # no need to do an if, it'll be empty if @pri_index is empty anyway
-
- my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
- my @const_rows;
+ return keys %$rels ? [ $columns, $rels ] : [$columns];
+}
- do { # no need to check anything at the front, we always want the first row
+# two arguments: $as_proto is an arrayref of column names,
+# $row_ref is an arrayref of the data. If none of the row data
+# is defined we return undef (that's copied from the old
+# _collapse_result). Next we decide whether we need to collapse
+# the resultset (i.e. we prefetch something) or not. $collapse
+# indicates that. The do-while loop will run once if we do not need
+# to collapse the result and will run as long as _merge_result returns
+# a true value. It will return undef if the current added row does not
+# match the previous row. A bit of stashing and cursor magic is
+# required so that the cursor is not mixed up.
- my %const;
+# "$rows" is a bit misleading. In the end, there should only be one
+# element in this arrayref.
- foreach my $this_as (@construct_as) {
- $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
+sub _collapse_result {
+ my ( $self, $as_proto, $row_ref ) = @_;
+ my $has_def;
+ for (@$row_ref) {
+ if ( defined $_ ) {
+ $has_def++;
+ last;
+ }
}
-
- push(@const_rows, \%const);
-
- } until ( # no pri_index => no collapse => drop straight out
- !@pri_index
- or
- do { # get another row, stash it, drop out if different PK
-
- @copy = $self->cursor->next;
- $self->{stashed_row} = \@copy;
-
- # last thing in do block, counts as true if anything doesn't match
-
- # check xor defined first for NULL vs. NOT NULL then if one is
- # defined the other must be so check string equality
-
- grep {
- (defined $pri_vals{$_} ^ defined $copy[$_])
- || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
- } @pri_index;
- }
- );
-
- my $alias = $self->{attrs}{alias};
- my $info = [];
-
- my %collapse_pos;
-
- my @const_keys;
-
- foreach my $const (@const_rows) {
- scalar @const_keys or do {
- @const_keys = sort { length($a) <=> length($b) } keys %$const;
- };
- foreach my $key (@const_keys) {
- if (length $key) {
- my $target = $info;
- my @parts = split(/\./, $key);
- my $cur = '';
- my $data = $const->{$key};
- foreach my $p (@parts) {
- $target = $target->[1]->{$p} ||= [];
- $cur .= ".${p}";
- if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
- # collapsing at this point and on final part
- my $pos = $collapse_pos{$cur};
- CK: foreach my $ck (@ckey) {
- if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
- $collapse_pos{$cur} = $data;
- delete @collapse_pos{ # clear all positioning for sub-entries
- grep { m/^\Q${cur}.\E/ } keys %collapse_pos
- };
- push(@$target, []);
- last CK;
- }
+ return undef unless $has_def;
+
+ my $collapse = keys %{ $self->{_attrs}{collapse} || {} };
+ my $rows = [];
+ my @row = @$row_ref;
+ do {
+ my $i = 0;
+ my $row = { map { $_ => $row[ $i++ ] } @$as_proto };
+ $row = $self->_unflatten_result($row);
+ unless ( scalar @$rows ) {
+ push( @$rows, $row );
+ }
+ $collapse = undef unless ( $self->_merge_result( $rows, $row ) );
+ } while (
+ $collapse
+ && do { @row = $self->cursor->next; $self->{stashed_row} = \@row if @row; }
+ );
+
+ return $rows->[0];
+
+}
+
+# _merge_result accepts an arrayref of rows objects (again, an arrayref of two elements)
+# and a row object which should be merged into the first object.
+# First we try to find out whether $row is already in $rows. If this is the case
+# we try to merge them by iteration through their relationship data. We call
+# _merge_result again on them, so they get merged.
+
+# If we don't find the $row in $rows, we append it to $rows and return undef.
+# _merge_result returns 1 otherwise (i.e. $row has been found in $rows).
+
+sub _merge_result {
+ my ( $self, $rows, $row ) = @_;
+ my ( $columns, $rels ) = @$row;
+ my $found = undef;
+ foreach my $seen (@$rows) {
+ my $match = 1;
+ foreach my $column ( keys %$columns ) {
+ if ( defined $seen->[0]->{$column} ^ defined $columns->{$column}
+ or defined $columns->{$column}
+ && $seen->[0]->{$column} ne $columns->{$column} )
+ {
+
+ $match = 0;
+ last;
}
- }
- if (exists $collapse{$cur}) {
- $target = $target->[-1];
- }
}
- $target->[0] = $data;
- } else {
- $info->[0] = $const->{$key};
- }
+ if ($match) {
+ $found = $seen;
+ last;
+ }
}
- }
+ if ($found) {
+ foreach my $rel ( keys %$rels ) {
+ my $old_rows = $found->[1]->{$rel};
+ $self->_merge_result(
+ ref $found->[1]->{$rel}->[0] eq 'HASH' ? [ $found->[1]->{$rel} ]
+ : $found->[1]->{$rel},
+ ref $rels->{$rel}->[0] eq 'HASH' ? [ $rels->{$rel}->[0], $rels->{$rel}->[1] ]
+ : $rels->{$rel}->[0]
+ );
+
+ }
- return $info;
+ }
+ else {
+ push( @$rows, $row );
+ return undef;
+ }
+
+ return 1;
}
+
=head2 result_source
=over 4
"Can't prefetch has_many ${pre} (join cond too complex)")
unless ref($rel_info->{cond}) eq 'HASH';
my $dots = @{[$as_prefix =~ m/\./g]} + 1; # +1 to match the ".${as_prefix}"
- if (my ($fail) = grep { @{[$_ =~ m/\./g]} == $dots }
- keys %{$collapse}) {
- my ($last) = ($fail =~ /([^\.]+)$/);
- carp (
- "Prefetching multiple has_many rels ${last} and ${pre} "
- .(length($as_prefix)
- ? "at the same level (${as_prefix}) "
- : "at top level "
- )
- . 'will explode the number of row objects retrievable via ->next or ->all. '
- . 'Use at your own risk.'
- );
- }
+
#my @col = map { (/^self\.(.+)$/ ? ("${as_prefix}.$1") : ()); }
# values %{$rel_info->{cond}};
$collapse->{".${as_prefix}${pre}"} = [ $rel_source->primary_columns ];
"Can't prefetch has_many ${pre} (join cond too complex)")
unless ref($rel_info->{cond}) eq 'HASH';
my $dots = @{[$as_prefix =~ m/\./g]} + 1; # +1 to match the ".${as_prefix}"
- if (my ($fail) = grep { @{[$_ =~ m/\./g]} == $dots }
- keys %{$collapse}) {
- my ($last) = ($fail =~ /([^\.]+)$/);
- carp (
- "Prefetching multiple has_many rels ${last} and ${pre} "
- .(length($as_prefix)
- ? "at the same level (${as_prefix}) "
- : "at top level "
- )
- . 'will explode the number of row objects retrievable via ->next or ->all. '
- . 'Use at your own risk.'
- );
- }
+
#my @col = map { (/^self\.(.+)$/ ? ("${as_prefix}.$1") : ()); }
# values %{$rel_info->{cond}};
$collapse->{".${as_prefix}${pre}"} = [ $rel_source->primary_columns ];
my $schema = DBICTest->init_schema();
-plan tests => 24;
+plan tests => 23;
my $rs = $schema->resultset('CD')->search({},
{
}
);
-is_deeply (
- $sub_rs->single,
- {
- artist => 1,
- track_position => 2,
- tracks =>
- {
- trackid => 17,
- title => 'Apiary',
- },
- },
- 'columns/select/as fold properly on sub-searches',
-);
-
-TODO: {
- local $TODO = "Multi-collapsing still doesn't work right - HRI should be getting an arrayref, not an individual hash";
- is_deeply (
+is_deeply(
$sub_rs->single,
{
- artist => 1,
- track_position => 2,
- tracks => [
- {
- trackid => 17,
- title => 'Apiary',
- },
- ],
+ artist => 1,
+ track_position => 2,
+ tracks => [
+ {
+ trackid => 17,
+ title => 'Apiary',
+ },
+ ],
},
'columns/select/as fold properly on sub-searches',
- );
-}
+);
+
+
my $datahashref = $hashrefinf[$index];
is ($track->cd->artist->name, $datahashref->{name}, 'Brought back correct artist');
- for my $col (keys %{$datahashref->{cds}{tracks}}) {
- is ($track->get_column ($col), $datahashref->{cds}{tracks}{$col}, "Correct track '$col'");
+ for my $col (keys %{$datahashref->{cds}[0]{tracks}[0]}) {
+ is ($track->get_column ($col), $datahashref->{cds}[0]{tracks}[0]{$col}, "Correct track '$col'");
}
}
is($artwork->cd->artist->artistid, 1, $name . ', correct artist_id over cd');
is($artwork->artwork_to_artist->first->artist->artistid, 2, $name . ', correct artist_id over A2A');
}
-}
\ No newline at end of file
+}
'(
SELECT me.cd, me.track_count, cd.cdid, cd.artist, cd.title, cd.year, cd.genreid, cd.single_track
FROM (
- SELECT me.cd, COUNT (me.trackid) AS track_count,
+ SELECT me.cd, COUNT (me.trackid) AS track_count
FROM track me
JOIN cd cd ON cd.cdid = me.cd
WHERE ( me.cd IN ( ?, ?, ?, ?, ? ) )
GROUP BY me.cd
- ) as me
+ ) me
JOIN cd cd ON cd.cdid = me.cd
WHERE ( me.cd IN ( ?, ?, ?, ?, ? ) )
)',
tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at, tracks.small_dt,
liner_notes.liner_id, liner_notes.notes
FROM (
- SELECT me.cdid, COUNT( tracks.trackid ) AS track_count, MAX( tracks.trackid ) AS maxtr,
+ SELECT me.cdid, COUNT( tracks.trackid ) AS track_count, MAX( tracks.trackid ) AS maxtr
FROM cd me
LEFT JOIN track tracks ON tracks.cd = me.cdid
WHERE ( me.cdid IS NOT NULL )
$rs->as_query,
'(
SELECT me.cdid, me.artist, me.title, me.year, me.genreid, me.single_track,
- tags.tagid, tags.cd, tags.tag
+ tags.tagid, tags.cd, tags.tag
FROM (
SELECT me.cdid, me.artist, me.title, me.year, me.genreid, me.single_track
FROM cd me
use strict;
-use warnings;
+use warnings;
use Test::More;
use Test::Exception;
use DBICTest;
use IO::File;
-plan tests => 10;
-
my $schema = DBICTest->init_schema();
my $sdebug = $schema->storage->debug;
+#( 1 -> M + M )
+my $cd_rs = $schema->resultset('CD')->search( { 'me.title' => 'Forkful of bees' } );
+my $pr_cd_rs = $cd_rs->search( {}, { prefetch => [qw/tracks tags/], } );
-# once the following TODO is complete, remove the 2 warning tests immediately
-# after the TODO block
-# (the TODO block itself contains tests ensuring that the warns are removed)
-TODO: {
- local $TODO = 'Prefetch of multiple has_many rels at the same level (currently warn to protect the clueless git)';
-
- #( 1 -> M + M )
- my $cd_rs = $schema->resultset('CD')->search ({ 'me.title' => 'Forkful of bees' });
- my $pr_cd_rs = $cd_rs->search ({}, {
- prefetch => [qw/tracks tags/],
- });
-
- my $tracks_rs = $cd_rs->first->tracks;
- my $tracks_count = $tracks_rs->count;
-
- my ($pr_tracks_rs, $pr_tracks_count);
-
- my $queries = 0;
- $schema->storage->debugcb(sub { $queries++ });
- $schema->storage->debug(1);
-
- my $o_mm_warn;
- {
- local $SIG{__WARN__} = sub { $o_mm_warn = shift };
- $pr_tracks_rs = $pr_cd_rs->first->tracks;
- };
- $pr_tracks_count = $pr_tracks_rs->count;
-
- ok(! $o_mm_warn, 'no warning on attempt to prefetch several same level has_many\'s (1 -> M + M)');
-
- is($queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query');
- $schema->storage->debugcb (undef);
- $schema->storage->debug ($sdebug);
+my $tracks_rs = $cd_rs->first->tracks;
+my $tracks_count = $tracks_rs->count;
- is($pr_tracks_count, $tracks_count, 'equal count of prefetched relations over several same level has_many\'s (1 -> M + M)');
- is ($pr_tracks_rs->all, $tracks_rs->all, 'equal amount of objects returned with and without prefetch over several same level has_many\'s (1 -> M + M)');
+my ( $pr_tracks_rs, $pr_tracks_count );
- #( M -> 1 -> M + M )
- my $note_rs = $schema->resultset('LinerNotes')->search ({ notes => 'Buy Whiskey!' });
- my $pr_note_rs = $note_rs->search ({}, {
- prefetch => {
- cd => [qw/tracks tags/]
- },
- });
+my $queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
- my $tags_rs = $note_rs->first->cd->tags;
- my $tags_count = $tags_rs->count;
-
- my ($pr_tags_rs, $pr_tags_count);
-
- $queries = 0;
- $schema->storage->debugcb(sub { $queries++ });
- $schema->storage->debug(1);
-
- my $m_o_mm_warn;
- {
- local $SIG{__WARN__} = sub { $m_o_mm_warn = shift };
- $pr_tags_rs = $pr_note_rs->first->cd->tags;
- };
- $pr_tags_count = $pr_tags_rs->count;
-
- ok(! $m_o_mm_warn, 'no warning on attempt to prefetch several same level has_many\'s (M -> 1 -> M + M)');
-
- is($queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query');
- $schema->storage->debugcb (undef);
- $schema->storage->debug ($sdebug);
-
- is($pr_tags_count, $tags_count, 'equal count of prefetched relations over several same level has_many\'s (M -> 1 -> M + M)');
- is($pr_tags_rs->all, $tags_rs->all, 'equal amount of objects with and without prefetch over several same level has_many\'s (M -> 1 -> M + M)');
-}
-
-# remove this closure once the TODO above is working
+my $o_mm_warn;
+{
+ local $SIG{__WARN__} = sub { $o_mm_warn = shift };
+ $pr_tracks_rs = $pr_cd_rs->first->tracks;
+};
+$pr_tracks_count = $pr_tracks_rs->count;
+
+ok( !$o_mm_warn,
+'no warning on attempt to prefetch several same level has_many\'s (1 -> M + M)'
+);
+
+is( $queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query' );
+$schema->storage->debugcb(undef);
+$schema->storage->debug($sdebug);
+
+is( $pr_tracks_count, $tracks_count,
+'equal count of prefetched relations over several same level has_many\'s (1 -> M + M)'
+);
+is( $pr_tracks_rs->all, $tracks_rs->all,
+'equal amount of objects returned with and without prefetch over several same level has_many\'s (1 -> M + M)'
+);
+
+#( M -> 1 -> M + M )
+my $note_rs =
+ $schema->resultset('LinerNotes')->search( { notes => 'Buy Whiskey!' } );
+my $pr_note_rs =
+ $note_rs->search( {}, { prefetch => { cd => [qw/tracks tags/] }, } );
+
+my $tags_rs = $note_rs->first->cd->tags;
+my $tags_count = $tags_rs->count;
+
+my ( $pr_tags_rs, $pr_tags_count );
+
+$queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
+
+my $m_o_mm_warn;
{
- my $warn_re = qr/will explode the number of row objects retrievable via/;
-
- my (@w, @dummy);
- local $SIG{__WARN__} = sub { $_[0] =~ $warn_re ? push @w, @_ : warn @_ };
-
- my $rs = $schema->resultset('CD')->search ({ 'me.title' => 'Forkful of bees' }, { prefetch => [qw/tracks tags/] });
- @w = ();
- @dummy = $rs->first;
- is (@w, 1, 'warning on attempt prefetching several same level has_manys (1 -> M + M)');
-
- my $rs2 = $schema->resultset('LinerNotes')->search ({ notes => 'Buy Whiskey!' }, { prefetch => { cd => [qw/tags tracks/] } });
- @w = ();
- @dummy = $rs2->first;
- is (@w, 1, 'warning on attempt prefetching several same level has_manys (M -> 1 -> M + M)');
-}
-
-__END__
-The solution is to rewrite ResultSet->_collapse_result() and
-ResultSource->resolve_prefetch() to focus on the final results from the collapse
-of the data. Right now, the code doesn't treat the columns from the various
-tables as grouped entities. While there is a concept of hierarchy (so that
-prefetching down relationships does work as expected), there is no idea of what
-the final product should look like and how the various columns in the row would
-play together. So, the actual prefetch datastructure from the search would be
-very useful in working through this problem. We already have access to the PKs
-and sundry for those. So, when collapsing the search result, we know we are
-looking for 1 cd object. We also know we're looking for tracks and tags records
--independently- of each other. So, we can grab the data for tracks and data for
-tags separately, uniqueing on the PK as appropriate. Then, when we're done with
-the given cd object's datastream, we know we're good. This should work for all
-the various scenarios.
-
-My reccommendation is the row's data is preprocessed first, breaking it up into
-the data for each of the component tables. (This could be done in the single
-table case, too, but probably isn't necessary.) So, starting with something
-like:
- my $row = {
- t1.col1 => 1,
- t1.col2 => 2,
- t2.col1 => 3,
- t2.col2 => 4,
- t3.col1 => 5,
- t3.col2 => 6,
- };
-it is massaged to look something like:
- my $row_massaged = {
- t1 => { col1 => 1, col2 => 2 },
- t2 => { col1 => 3, col2 => 4 },
- t3 => { col1 => 5, col2 => 6 },
- };
-At this point, find the stuff that's different is easy enough to do and slotting
-things into the right spot is, likewise, pretty straightforward. Instead of
-storing things in a AoH, store them in a HoH keyed on the PKs of the the table,
-then convert to an AoH after all collapsing is done.
-
-This implies that the collapse attribute can probably disappear or, at the
-least, be turned into a boolean (which is how it's used in every other place).
+ local $SIG{__WARN__} = sub { $m_o_mm_warn = shift };
+ $pr_tags_rs = $pr_note_rs->first->cd->tags;
+};
+$pr_tags_count = $pr_tags_rs->count;
+
+ok( !$m_o_mm_warn,
+'no warning on attempt to prefetch several same level has_many\'s (M -> 1 -> M + M)'
+);
+
+is( $queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query' );
+$schema->storage->debugcb(undef);
+$schema->storage->debug($sdebug);
+
+is( $pr_tags_count, $tags_count,
+'equal count of prefetched relations over several same level has_many\'s (M -> 1 -> M + M)'
+);
+is( $pr_tags_rs->all, $tags_rs->all,
+'equal amount of objects with and without prefetch over several same level has_many\'s (M -> 1 -> M + M)'
+);
+
+done_testing;
# try with double limit
my $artist2 = $use_prefetch->search({'cds.title' => { '!=' => $artist_many_cds->cds->first->title } })->slice (0,0)->next;
is($artist2->cds->count, 2, "count on search limiting prefetched has_many");
-
projects / dbsrgits/DBIx-Class.git / commitdiff