}
# Run the query
- my $rs = $self->search ($query, $attrs);
- if (keys %{$rs->_resolved_attrs->{collapse}}) {
+ my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs});
+ if ($rs->_resolved_attrs->{collapse}) {
my $row = $rs->next;
carp "Query returned more than one row" if $rs->next;
return $row;
my $attrs = $self->_resolved_attrs_copy;
- if (keys %{$attrs->{collapse}}) {
+ if ($attrs->{collapse}) {
$self->throw_exception(
'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
);
return @new;
}
-sub _collapse_result {
- my ($self, $as_proto, $row) = @_;
-
- my @copy = @$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
+# 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. $collapse
+# indicates that. The do-while loop will run once if we do not need
+# to collapse the result and will run as long as _merge_result returns
+# a true value. It will return undef if the current added row does not
+# match the previous row. A bit of stashing and cursor magic is
+# required so that the cursor is not mixed up.
- # store just the index so we can check the array positions from the row
- # without having to contruct the full hash
+# "$rows" is a bit misleading. In the end, there should only be one
+# element in this arrayref.
- 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!)
+sub _collapse_result {
+ my ( $self, $as_proto, $row_ref ) = @_;
+ my $has_def;
+ for (@$row_ref) {
+ if ( defined $_ ) {
+ $has_def++;
+ last;
+ }
}
- }
-
- # no need to do an if, it'll be empty if @pri_index is empty anyway
-
- my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
-
- my @const_rows;
-
- do { # no need to check anything at the front, we always want the first row
-
- my %const;
-
- foreach my $this_as (@construct_as) {
- $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
+ return undef unless $has_def;
+
+ my $collapse = $self->_resolved_attrs->{collapse};
+ my $rows = [];
+ my @row = @$row_ref;
+ do {
+ my $i = 0;
+ my $row = { map { $_ => $row[ $i++ ] } @$as_proto };
+ $row = $self->result_source->_parse_row($row, $collapse);
+ unless ( scalar @$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} )
+ {
+
+ $match = 0;
+ last;
+ }
+ }
+ if ($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]
+ );
- 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;
- }
- }
- }
- if (exists $collapse{$cur}) {
- $target = $target->[-1];
- }
}
- $target->[0] = $data;
- } else {
- $info->[0] = $const->{$key};
- }
+
+ }
+ else {
+ push( @$rows, $row );
+ return undef;
}
- }
- return $info;
+ return 1;
}
+
=head2 result_source
=over 4
# if we multi-prefetch we group_by primary keys only as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
- if ( keys %{$attrs->{collapse}} ) {
+ if ( $attrs->{collapse} ) {
$sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
}
my @obj;
- if (keys %{$self->_resolved_attrs->{collapse}}) {
+ if ($self->_resolved_attrs->{collapse}) {
# Using $self->cursor->all is really just an optimisation.
# If we're collapsing has_many prefetches it probably makes
# very little difference, and this is cleaner than hacking
}
}
else {
-
# otherwise we intialise select & as to empty
$attrs->{select} = [];
$attrs->{as} = [];
}
}
- $attrs->{collapse} ||= {};
if ( my $prefetch = delete $attrs->{prefetch} ) {
- $prefetch = $self->_merge_attr( {}, $prefetch );
+ $attrs->{collapse} = 1;
my $prefetch_ordering = [];
}
}
- my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
+ my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering );
# we need to somehow mark which columns came from prefetch
$attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
$attrs->{_collapse_order_by} = \@$prefetch_ordering;
}
+ # run through the resulting joinstructure (starting from our current slot)
+ # and unset collapse if proven unnesessary
+ if ($attrs->{collapse} && ref $attrs->{from} eq 'ARRAY') {
+
+ if (@{$attrs->{from}} > 1) {
+
+ # find where our table-spec starts and consider only things after us
+ my @fromlist = @{$attrs->{from}};
+ while (@fromlist) {
+ my $t = shift @fromlist;
+ $t = $t->[0] if ref $t eq 'ARRAY'; #me vs join from-spec mismatch
+ last if ($t->{-alias} && $t->{-alias} eq $alias);
+ }
+
+ if (@fromlist) {
+ $attrs->{collapse} = scalar grep { ! $_->[0]{-is_single} } (@fromlist);
+ }
+ }
+ else {
+ # no joins - no collapse
+ $attrs->{collapse} = 0;
+ }
+ }
+
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# been doing
projects / dbsrgits/DBIx-Class.git / blobdiff