[Bast-commits] r7372 - in DBIx-Class/0.08/branches/prefetch: lib/DBIx/Class t/prefetch

mo at dev.catalyst.perl.org mo at dev.catalyst.perl.org
Mon Aug 24 13:11:57 GMT 2009


Author: mo
Date: 2009-08-24 13:11:52 +0000 (Mon, 24 Aug 2009)
New Revision: 7372

Modified:
   DBIx-Class/0.08/branches/prefetch/lib/DBIx/Class/ResultSet.pm
   DBIx-Class/0.08/branches/prefetch/t/prefetch/multiple_hasmany.t
Log:
cleaned up test and added XOR comparison

Modified: DBIx-Class/0.08/branches/prefetch/lib/DBIx/Class/ResultSet.pm
===================================================================
--- DBIx-Class/0.08/branches/prefetch/lib/DBIx/Class/ResultSet.pm	2009-08-24 12:42:57 UTC (rev 7371)
+++ DBIx-Class/0.08/branches/prefetch/lib/DBIx/Class/ResultSet.pm	2009-08-24 13:11:52 UTC (rev 7372)
@@ -1020,23 +1020,24 @@
         && do { @row = $self->cursor->next; $self->{stashed_row} = \@row if @row; }
       );
 
-    #use Data::Dumper; $Data::Dumper::Indent = 1; warn Dumper $rows->[0];
-
     return $rows->[0];
 
 }
 
+#use List::Util qw(first);
+
 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 $columns->{$column} # TODO: XOR!
+            if (   defined $seen->[0]->{$column} ^ defined $columns->{$column}
+                or defined $columns->{$column}
                 && $seen->[0]->{$column} ne $columns->{$column} )
             {
+
                 $match = 0;
                 last;
             }

Modified: DBIx-Class/0.08/branches/prefetch/t/prefetch/multiple_hasmany.t
===================================================================
--- DBIx-Class/0.08/branches/prefetch/t/prefetch/multiple_hasmany.t	2009-08-24 12:42:57 UTC (rev 7371)
+++ DBIx-Class/0.08/branches/prefetch/t/prefetch/multiple_hasmany.t	2009-08-24 13:11:52 UTC (rev 7372)
@@ -1,5 +1,5 @@
 use strict;
-use warnings;  
+use warnings;
 
 use Test::More;
 use Test::Exception;
@@ -7,190 +7,84 @@
 use DBICTest;
 use IO::File;
 
-plan tests => 10;
-
 my $schema = DBICTest->init_schema();
 my $sdebug = $schema->storage->debug;
 
+local $TODO =
+'Prefetch of multiple has_many rels at the same level (currently warn to protect the clueless git)';
 
-# 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/], } );
 
-    #( 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 $tracks_rs = $cd_rs->first->tracks;
-    my $tracks_count = $tracks_rs->count;
+my ( $pr_tracks_rs, $pr_tracks_count );
 
-    my ($pr_tracks_rs, $pr_tracks_count);
+my $queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
 
-    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;
 
-    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)'
+);
 
-    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($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)'
+);
 
-    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/] }, } );
 
-    #( 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 $tags_rs = $note_rs->first->cd->tags;
-    my $tags_count = $tags_rs->count;
+my ( $pr_tags_rs, $pr_tags_count );
 
-    my ($pr_tags_rs, $pr_tags_count);
+$queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
 
-    $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 $m_o_mm_warn;
 {
-    my $warn_re = qr/will explode the number of row objects retrievable via/;
+    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;
 
-    my (@w, @dummy);
-    local $SIG{__WARN__} = sub { $_[0] =~ $warn_re ? push @w, @_ : warn @_ };
+ok( !$m_o_mm_warn,
+'no warning on attempt to prefetch several same level has_many\'s (M -> 1 -> M + M)'
+);
 
-    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)');
+is( $queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query' );
+$schema->storage->debugcb(undef);
+$schema->storage->debug($sdebug);
 
-    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)');
-}
-
-
-# Illustration purposes only
-
-{
-  package Inf::Dump;
-  sub inflate_result {
-    return [ @_[2,3] ];
-  }
-}
-
-my $cd = $schema->resultset ('CD')->create ({
-  artist => 1,
-  title => 'bad cd',
-  year => 1313,
-  tags => [ map { { tag => "bad tag $_" } } (1 .. 3) ],
-  tracks => [
-    { title => 'bad track 1', cd_single => {
-      artist => 1,
-      title => 'bad_single',
-      year => 1313,
-    }},
-    map { { title => "bad track $_" } } (2 .. 3),
-  ],
-});
-
-my $rs = $schema->resultset ('CD')->search (
-  { 'me.cdid' => $cd->id },
-  { prefetch => [ 'tags', { tracks => 'cd_single' } ], result_class => 'Inf::Dump' },
+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)'
+);
 
-use Text::Table;
-my $query = ${$rs->as_query}->[0];
-my ($cols) = ( $query =~ /SELECT (.+) FROM/);
-my $tb = Text::Table->new (map { $_ => \ ' | ' } (split /,\s*/, $cols) );
+done_testing;
 
-my $c = $rs->cursor;
-while (my @stuff = $c->next) {
-  $tb->add (map { defined $_ ? $_ : 'NULL' } (@stuff) );
-}
-
-$rs->reset;
-use Data::Dumper;
-diag Dumper [
-  "\n$query",
-  "\n$tb",
-  $rs->next
-];
-
-
-
-
-__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).




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