=head1 NAME
-DBIx::Class::ResultClass::HashRefInflator
+DBIx::Class::ResultClass::HashRefInflator - Get raw hashrefs from a resultset
=head1 SYNOPSIS
- my $rs = $schema->resultset('CD');
+ use DBIx::Class::ResultClass::HashRefInflator;
+ my $rs = $schema->resultset('CD');
$rs->result_class('DBIx::Class::ResultClass::HashRefInflator');
+ while (my $hashref = $rs->next) {
+ ...
+ }
=head1 DESCRIPTION
-DBIx::Class is not built for speed: it's built for convenience and
-ease of use. But sometimes you just need to get the data, and skip the
-fancy objects. That is what this class provides.
+DBIx::Class is faster than older ORMs like Class::DBI but it still isn't
+designed primarily for speed. Sometimes you need to quickly retrieve the data
+from a massive resultset, while skipping the creation of fancy row objects.
+Specifying this class as a C<result_class> for a resultset will change C<< $rs->next >>
+to return a plain data hash-ref (or a list of such hash-refs if C<< $rs->all >> is used).
-There are two ways of using this class.
+There are two ways of applying this class to a resultset:
=over
=back
-=head1 AUTOMATICALLY INFLATING COLUMN VALUES
-
-So you want to skip the DBIx::Class object creation part, but you still want
-all your data to be inflated according to the rules you defined in your table
-classes. Setting the global variable
-C<$DBIx::Class::ResultClass::HashRefInflator::inflate_data> to a true value
-will instruct L<mk_hash> to interrogate the processed columns and apply any
-inflation methods declared via L<DBIx::Class::InflateColumn/inflate_column>.
-
-For increased speed the inflation method lookups are cached in
-C<%DBIx::Class::ResultClass::HashRefInflator::inflator_cache>. Make sure to
-reset this hash if you modify column inflators at run time.
-
-=head1 METHODS
-
-=head2 inflate_result
-
-Inflates the result and prefetched data into a hash-ref using L<mk_hash>.
-
-=cut
-
-sub inflate_result {
- my ($self, $source, $me, $prefetch) = @_;
-
- my $hashref = mk_hash($me, $prefetch);
- return $hashref;
-}
-
-=head2 mk_hash
-
-This does all the work of inflating the (pre)fetched data.
-
=cut
##############
# NOTE
#
-# Generally people use this to gain as much speed as possible. If a new mk_hash is
+# Generally people use this to gain as much speed as possible. If a new &mk_hash is
# implemented, it should be benchmarked using the maint/benchmark_hashrefinflator.pl
-# script (in addition to passing all tests of course :). Additional instructions are
+# script (in addition to passing all tests of course :). Additional instructions are
# provided in the script itself.
#
-sub mk_hash {
+# This coderef is a simple recursive function
+# Arguments: ($me, $prefetch) from inflate_result() below
+my $mk_hash;
+$mk_hash = sub {
if (ref $_[0] eq 'ARRAY') { # multi relationship
- return [ map { mk_hash (@$_) || () } (@_) ];
+ return [ map { $mk_hash->(@$_) || () } (@_) ];
}
else {
my $hash = {
# the second arg is a hash of arrays for each prefetched relation
map
- { $_ => mk_hash( @{$_[1]->{$_}} ) }
+ { $_ => $mk_hash->( @{$_[1]->{$_}} ) }
( $_[1] ? (keys %{$_[1]}) : () )
};
# if there is at least one defined column consider the resultset real
# (and not an emtpy has_many rel containing one empty hashref)
+ # an empty arrayref is an empty multi-sub-prefetch - don't consider
+ # those either
for (values %$hash) {
- return $hash if defined $_;
+ if (ref $_ eq 'ARRAY') {
+ return $hash if @$_;
+ }
+ elsif (defined $_) {
+ return $hash;
+ }
}
return undef;
}
+};
+
+=head1 METHODS
+
+=head2 inflate_result
+
+Inflates the result and prefetched data into a hash-ref (invoked by L<DBIx::Class::ResultSet>)
+
+=cut
+
+##################################################################################
+# inflate_result is invoked as:
+# HRI->inflate_result ($resultsource_instance, $main_data_hashref, $prefetch_data_hashref)
+sub inflate_result {
+ return $mk_hash->($_[2], $_[3]);
}
-=head1 CAVEAT
+
+=head1 CAVEATS
+
+=over
+
+=item *
This will not work for relationships that have been prefetched. Consider the
following:
HashRefInflator only affects resultsets at inflation time, and prefetch causes
relations to be inflated when the master C<$artist> row is inflated.
+=item *
+
+Column value inflation, e.g., using modules like
+L<DBIx::Class::InflateColumn::DateTime>, is not performed.
+The returned hash contains the raw database values.
+
+=back
+
=cut
1;
projects / dbsrgits/DBIx-Class.git / blobdiff