X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=3112cb51d6b8efda9eb26a73952142d601abd6db;hb=81e4dc3d93646a11bee973606a31be412f23cd5f;hp=2c0207e7bc94769e88ab36d04786903bdbfd4d78;hpb=4e9fc3f33df616fb7340d05e304ff985b9cce9cb;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 2c0207e..3112cb5 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -207,11 +207,23 @@ automatically get one from e.g. a L called in scalar context: my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); -IMPORTANT: If called on an object, proxies to new_result instead so +=over + +=item WARNING + +If called on an object, proxies to L instead, so my $cd = $schema->resultset('CD')->new({ title => 'Spoon' }); -will return a CD object, not a ResultSet. +will return a CD object, not a ResultSet, and is equivalent to: + + my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' }); + +Please also keep in mind that many internals call C directly, +so overloading this method with the idea of intercepting new result object +creation B. See also warning pertaining to L. + +=back =cut @@ -829,7 +841,7 @@ sub find { # Run the query, passing the result_class since it should propagate for find my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs}); - if ($rs->_resolved_attrs->{collapse}) { + if (keys %{$rs->_resolved_attrs->{collapse}}) { my $row = $rs->next; carp "Query returned more than one row" if $rs->next; return $row; @@ -1038,9 +1050,11 @@ sub single { my $attrs = $self->_resolved_attrs_copy; - $self->throw_exception( - 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead' - ) if $attrs->{collapse}; + if (keys %{$attrs->{collapse}}) { + $self->throw_exception( + 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead' + ); + } if ($where) { if (defined $attrs->{where}) { @@ -1054,13 +1068,12 @@ sub single { } } - my $data = [ $self->result_source->storage->select_single( + my @data = $self->result_source->storage->select_single( $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs - )]; - return undef unless @$data; - $self->{stashed_rows} = [ $data ]; - $self->_construct_objects->[0]; + ); + + return (@data ? ($self->_construct_object(@data))[0] : undef); } @@ -1217,145 +1230,161 @@ first record from the resultset. sub next { my ($self) = @_; - if (my $cache = $self->get_cache) { $self->{all_cache_position} ||= 0; return $cache->[$self->{all_cache_position}++]; } - if ($self->{attrs}{cache}) { delete $self->{pager}; $self->{all_cache_position} = 1; return ($self->all)[0]; } + if ($self->{stashed_objects}) { + my $obj = shift(@{$self->{stashed_objects}}); + delete $self->{stashed_objects} unless @{$self->{stashed_objects}}; + return $obj; + } + my @row = ( + exists $self->{stashed_row} + ? @{delete $self->{stashed_row}} + : $self->cursor->next + ); + return undef unless (@row); + my ($row, @more) = $self->_construct_object(@row); + $self->{stashed_objects} = \@more if @more; + return $row; +} - return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] }; - - $self->{stashed_objects} = $self->_construct_objects - or return undef; +sub _construct_object { + my ($self, @row) = @_; - return shift @{$self->{stashed_objects}}; + my $info = $self->_collapse_result($self->{_attrs}{as}, \@row) + or return (); + my @new = $self->result_class->inflate_result($self->result_source, @$info); + @new = $self->{_attrs}{record_filter}->(@new) + if exists $self->{_attrs}{record_filter}; + return @new; } -# takes a single DBI-row of data and coinstructs as many objects -# as the resultset attributes call for. -# This can be a bit of an action at a distance - it takes as an argument -# the *current* cursor-row (already taken off the $sth), but if -# collapsing is requested it will keep advancing the cursor either -# until the current row-object is assembled (the collapser was able to -# order the result sensibly) OR until the cursor is exhausted (an -# unordered collapsing resultset effectively triggers ->all) -sub _construct_objects { - my ($self, $fetch_all) = @_; +sub _collapse_result { + my ($self, $as_proto, $row) = @_; - my $rsrc = $self->result_source; - my $attrs = $self->_resolved_attrs; - my $cursor = $self->cursor; - - # this will be used as both initial raw-row collector AND as a RV of - # _construct_objects. Not regrowing the array twice matters a lot... - # a suprising amount actually - my $rows = (delete $self->{stashed_rows}) || []; - if ($fetch_all) { - # FIXME - we can do better, cursor->next/all (well diff. methods) should return a ref - $rows = [ @$rows, $cursor->all ]; - } - elsif (!$attrs->{collapse}) { - push @$rows, do { my @r = $cursor->next; @r ? \@r : () } - unless @$rows; - } - else { - $attrs->{_ordered_for_collapse} ||= (!$attrs->{order_by}) ? undef : do { - my $st = $rsrc->schema->storage; - my @ord_cols = map - { $_->[0] } - ( $st->_extract_order_criteria($attrs->{order_by}) ) - ; + my @copy = @$row; - my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols); + # 'foo' => [ undef, 'foo' ] + # 'foo.bar' => [ 'foo', 'bar' ] + # 'foo.bar.baz' => [ 'foo.bar', 'baz' ] - for (0 .. $#ord_cols) { - if ( - ! $colinfos->{$ord_cols[$_]} - or - $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc - ) { - splice @ord_cols, $_; - last; - } - } + my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto; - # since all we check here are the start of the order_by belonging to the - # top level $rsrc, the order stability check will fail unless the whole - # thing is ordered as we need it - (@ord_cols and $rsrc->_identifying_column_set({ map - { $colinfos->{$_}{-colname} => $colinfos->{$_} } - @ord_cols - })) ? 1 : 0; - }; + my %collapse = %{$self->{_attrs}{collapse}||{}}; - if ($attrs->{_ordered_for_collapse}) { - push @$rows, do { my @r = $cursor->next; @r ? \@r : () }; - } - # instead of looping over ->next, use ->all in stealth mode - elsif (! $cursor->{done}) { - push @$rows, $cursor->all; - $cursor->{done} = 1; - $fetch_all = 1; + my @pri_index; + + # if we're doing collapsing (has_many prefetch) we need to grab records + # until the PK changes, so fill @pri_index. if not, we leave it empty so + # we know we don't have to bother. + + # the reason for not using the collapse stuff directly is because if you + # had for e.g. two artists in a row with no cds, the collapse info for + # both would be NULL (undef) so you'd lose the second artist + + # store just the index so we can check the array positions from the row + # without having to contruct the full hash + + if (keys %collapse) { + my %pri = map { ($_ => 1) } $self->result_source->_pri_cols; + 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, $i); + } + last unless keys %pri; # short circuit (Johnny Five Is Alive!) } } - return undef unless @$rows; + # no need to do an if, it'll be empty if @pri_index is empty anyway - my $res_class = $self->result_class; - my $inflator = $res_class->can ('inflate_result') - or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method"); + my %pri_vals = map { ($_ => $copy[$_]) } @pri_index; - my $infmap = $attrs->{as}; + my @const_rows; - if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) { - # construct a much simpler array->hash folder for the one-table cases right here + do { # no need to check anything at the front, we always want the first row - # FIXME SUBOPTIMAL this is a very very very hot spot - # while rather optimal we can *still* do much better, by - # building a smarter [Row|HRI]::inflate_result(), and - # switch to feeding it data via a much leaner interface - # - # crude unscientific benchmarking indicated the shortcut eval is not worth it for - # this particular resultset size - if (@$rows < 60) { - my @as_idx = 0..$#$infmap; - for my $r (@$rows) { - $r = $inflator->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } @as_idx } ); - } - } - else { - eval sprintf ( - '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows', - join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) - ); + my %const; + + foreach my $this_as (@construct_as) { + $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy); } - } - else { - ($self->{_row_parser} ||= eval sprintf 'sub { %s }', $rsrc->_mk_row_parser({ - inflate_map => $infmap, - selection => $attrs->{select}, - collapse => $attrs->{collapse}, - }) or die $@)->($rows, $fetch_all ? () : ( - sub { my @r = $cursor->next or return; \@r }, - ($self->{stashed_rows} = []), - )); # modify $rows in-place, shrinking/extending as necessary - $_ = $inflator->($res_class, $rsrc, @$_) for @$rows; + 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; + $self->{stashed_row} = \@copy; + + # last thing in do block, counts as true if anything doesn't match + + # check xor defined first for NULL vs. NOT NULL then if one is + # defined the other must be so check string equality - # CDBI compat stuff - if ($attrs->{record_filter}) { - $_ = $attrs->{record_filter}->($_) for @$rows; + 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}; + } + } } - return $rows; + return $info; } =head2 result_source @@ -1526,7 +1555,7 @@ sub _count_subq_rs { # if we multi-prefetch we group_by something unique, as this is what we would # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless - if ( $attrs->{collapse} ) { + if ( keys %{$attrs->{collapse}} ) { $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{ $rsrc->_identifying_column_set || $self->throw_exception( 'Unable to construct a unique group_by criteria properly collapsing the ' @@ -1643,23 +1672,33 @@ Returns all elements in the resultset. sub all { my $self = shift; if(@_) { - $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()"); + $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()"); } - delete $self->{stashed_rows}; - delete $self->{stashed_objects}; - - if (my $c = $self->get_cache) { - return @$c; + return @{ $self->get_cache } if $self->get_cache; + + my @obj; + + if (keys %{$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 + # _construct_object to survive the approach + $self->cursor->reset; + my @row = $self->cursor->next; + while (@row) { + push(@obj, $self->_construct_object(@row)); + @row = (exists $self->{stashed_row} + ? @{delete $self->{stashed_row}} + : $self->cursor->next); + } + } else { + @obj = map { $self->_construct_object(@$_) } $self->cursor->all; } - $self->cursor->reset; - - my $objs = $self->_construct_objects('fetch_all') || []; - - $self->set_cache($objs) if $self->{attrs}{cache}; + $self->set_cache(\@obj) if $self->{attrs}{cache}; - return @$objs; + return @obj; } =head2 reset @@ -1680,10 +1719,7 @@ another query. sub reset { my ($self) = @_; - delete $self->{_attrs}; - delete $self->{stashed_rows}; - delete $self->{stashed_objects}; - + delete $self->{_attrs} if exists $self->{_attrs}; $self->{all_cache_position} = 0; $self->cursor->reset; return $self; @@ -1732,14 +1768,19 @@ sub _rs_update_delete { # simplify the joinmap and maybe decide if a grouping (and thus subquery) is necessary my $relation_classifications; if (ref($attrs->{from}) eq 'ARRAY') { - $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs); - - $relation_classifications = $storage->_resolve_aliastypes_from_select_args ( - [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ], - $attrs->{select}, - $cond, - $attrs - ) unless $needs_group_by_subq; # we already know we need a group, no point of resolving them + if (@{$attrs->{from}} == 1) { + # not a fucking JOIN at all, quit with the dickery + $relation_classifications = {}; + } else { + $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs); + + $relation_classifications = $storage->_resolve_aliastypes_from_select_args ( + [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ], + $attrs->{select}, + $cond, + $attrs + ) unless $needs_group_by_subq; # we already know we need a group, no point of resolving them + } } else { $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst @@ -1757,21 +1798,13 @@ sub _rs_update_delete { ) { # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus # a condition containing 'me' or other table prefixes will not work - # at all. What this code tries to do (badly) is to generate a condition - # with the qualifiers removed, by exploiting the quote mechanism of sqla - # - # this is atrocious and should be replaced by normal sqla introspection - # one sunny day - my ($sql, @bind) = do { - my $sqla = $rsrc->storage->sql_maker; - local $sqla->{_dequalify_idents} = 1; - $sqla->_recurse_where($self->{cond}); - } if $self->{cond}; - + # at all. Tell SQLMaker to dequalify idents via a gross hack. + my $sqla = $rsrc->storage->sql_maker; + local $sqla->{_dequalify_idents} = 1; return $rsrc->storage->$op( $rsrc, $op eq 'update' ? $values : (), - $self->{cond} ? \[$sql, @bind] : (), + $self->{cond}, ); } @@ -1786,7 +1819,7 @@ sub _rs_update_delete { my $existing_group_by = delete $attrs->{group_by}; # make a new $rs selecting only the PKs (that's all we really need for the subq) - delete $attrs->{$_} for qw/collapse select _prefetch_selector_range as/; + delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/; $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ]; $attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins my $subrs = (ref $self)->new($rsrc, $attrs); @@ -2287,7 +2320,11 @@ Passes the hashref of input on to L. sub new_result { my ($self, $values) = @_; - $self->throw_exception( "new_result needs a hash" ) + + $self->throw_exception( "new_result takes only one argument - a hashref of values" ) + if @_ > 2; + + $self->throw_exception( "new_result expects a hashref" ) unless (ref $values eq 'HASH'); my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values); @@ -2622,7 +2659,8 @@ it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a lot of the internals simply never call it, so your override will be bypassed more often than not. Override either L or L depending on how early in the -L process you need to intervene. +L process you need to intervene. See also warning pertaining to +L. =back @@ -3014,7 +3052,7 @@ sub related_resultset { if (my $cache = $self->get_cache) { if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) { - $new_cache = [ map { @{$_->related_resultset($rel)->get_cache||[]} } + $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} } @$cache ]; } } @@ -3317,10 +3355,14 @@ sub _resolved_attrs { if $attrs->{select}; # assume all unqualified selectors to apply to the current alias (legacy stuff) - $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel; + for (@sel) { + $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_"; + } - # disqualify all $alias.col as-bits (inflate-map mandated) - $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as; + # disqualify all $alias.col as-bits (collapser mandated) + for (@as) { + $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_; + } # de-duplicate the result (remove *identical* select/as pairs) # and also die on duplicate {as} pointing to different {select}s @@ -3407,17 +3449,15 @@ sub _resolved_attrs { } } - # generate selections based on the prefetch helper - my $prefetch; - $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} ) - if defined $attrs->{prefetch}; - - if ($prefetch) { + $attrs->{collapse} ||= {}; + if ($attrs->{prefetch}) { $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}") if $attrs->{_dark_selector}; - $attrs->{collapse} = 1; + my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} ); + + my $prefetch_ordering = []; # this is a separate structure (we don't look in {from} directly) # as the resolver needs to shift things off the lists to work @@ -3440,7 +3480,8 @@ sub _resolved_attrs { } } - my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map ); + my @prefetch = + $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} ); # we need to somehow mark which columns came from prefetch if (@prefetch) { @@ -3450,39 +3491,9 @@ sub _resolved_attrs { push @{ $attrs->{select} }, (map { $_->[0] } @prefetch); push @{ $attrs->{as} }, (map { $_->[1] } @prefetch); - } - - $attrs->{_single_object_inflation} = ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}}; - - # 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); - } - - for (@fromlist) { - $attrs->{collapse} = ! $_->[0]{-is_single} - and last; - } - } - else { - # no joins - no collapse - $attrs->{collapse} = 0; - } - } - - if (! $attrs->{order_by} and $attrs->{collapse}) { - # default order for collapsing unless the user asked for something - $attrs->{order_by} = [ map { "$alias.$_" } $source->primary_columns ]; - $attrs->{_ordered_for_collapse} = 1; + push( @{$attrs->{order_by}}, @$prefetch_ordering ); + $attrs->{_collapse_order_by} = \@$prefetch_ordering; } # if both page and offset are specified, produce a combined offset @@ -3707,9 +3718,6 @@ sub STORABLE_freeze { # A cursor in progress can't be serialized (and would make little sense anyway) delete $to_serialize->{cursor}; - # the parser can be regenerated - delete $to_serialize->{_row_parser}; - # nor is it sensical to store a not-yet-fired-count pager if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') { delete $to_serialize->{pager}; @@ -4008,6 +4016,12 @@ to Earth' and a cd with title 'Popular'. If you want to fetch related objects from other tables as well, see C below. + NOTE: An internal join-chain pruner will discard certain joins while + constructing the actual SQL query, as long as the joins in question do not + affect the retrieved result. This for example includes 1:1 left joins + that are not part of the restriction specification (WHERE/HAVING) nor are + a part of the query selection. + For more help on using joins with search, see L. =head2 prefetch @@ -4302,7 +4316,7 @@ attribute, this setting is ignored and an appropriate warning is issued. Adds to the WHERE clause. # only return rows WHERE deleted IS NULL for all searches - __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); ) + __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); Can be overridden by passing C<< { where => undef } >> as an attribute to a resultset. @@ -4333,12 +4347,13 @@ L. =over 4 -=item Value: ( 'update' | 'shared' ) +=item Value: ( 'update' | 'shared' | \$scalar ) =back Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT -... FOR SHARED. +... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the +query. =cut