X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSource.pm;h=6599a4a67586d18909d62ea5929dc2aeda67bbfa;hb=0c11ad0ee5c8407f6b87d6e15c62a1b445076dc0;hp=31b7eec05ad447e87ad8d37cfb7d4f86aae814ad;hpb=fe0708a2d68b5d34b6bc6f7e70164c3e569f1dd0;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSource.pm b/lib/DBIx/Class/ResultSource.pm index 31b7eec..6599a4a 100644 --- a/lib/DBIx/Class/ResultSource.pm +++ b/lib/DBIx/Class/ResultSource.pm @@ -3,19 +3,19 @@ package DBIx::Class::ResultSource; use strict; use warnings; -use base qw/DBIx::Class/; - use DBIx::Class::ResultSet; use DBIx::Class::ResultSourceHandle; use DBIx::Class::Exception; use DBIx::Class::Carp; -use DBIx::Class::GlobalDestruction; +use Devel::GlobalDestruction; use Try::Tiny; use List::Util 'first'; use Scalar::Util qw/blessed weaken isweak/; use namespace::clean; +use base qw/DBIx::Class/; + __PACKAGE__->mk_group_accessors(simple => qw/ source_name name source_info _ordered_columns _columns _primaries _unique_constraints @@ -1751,7 +1751,7 @@ sub _resolve_condition { # prefixed relative to the current source, in accordance with where they appear # in the supplied relationships. sub _resolve_prefetch { - my ($self, $pre, $alias, $alias_map, $order, $pref_path) = @_; + my ($self, $pre, $alias, $alias_map, $order, $collapse, $pref_path) = @_; $pref_path ||= []; if (not defined $pre or not length $pre) { @@ -1759,15 +1759,15 @@ sub _resolve_prefetch { } elsif( ref $pre eq 'ARRAY' ) { return - map { $self->_resolve_prefetch( $_, $alias, $alias_map, $order, [ @$pref_path ] ) } + map { $self->_resolve_prefetch( $_, $alias, $alias_map, $order, $collapse, [ @$pref_path ] ) } @$pre; } elsif( ref $pre eq 'HASH' ) { my @ret = map { - $self->_resolve_prefetch($_, $alias, $alias_map, $order, [ @$pref_path ] ), + $self->_resolve_prefetch($_, $alias, $alias_map, $order, $collapse, [ @$pref_path ] ), $self->related_source($_)->_resolve_prefetch( - $pre->{$_}, "${alias}.$_", $alias_map, $order, [ @$pref_path, $_] ) + $pre->{$_}, "${alias}.$_", $alias_map, $order, $collapse, [ @$pref_path, $_] ) } keys %$pre; return @ret; } @@ -1798,11 +1798,27 @@ sub _resolve_prefetch { 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}"} = [ $rel_source->_pri_cols ]; + # action at a distance. prepending the '.' allows simpler code + # in ResultSet->_collapse_result my @key = map { (/^foreign\.(.+)$/ ? ($1) : ()); } keys %{$rel_info->{cond}}; - push @$order, map { "${as}.$_" } @key; if (my $rel_order = $rel_info->{attrs}{order_by}) { @@ -1837,412 +1853,6 @@ sub _resolve_prefetch { } } -# Takes a selection list and generates a collapse-map representing -# row-object fold-points. Every relationship is assigned a set of unique, -# non-nullable columns (which may *not even be* from the same resultset) -# and the collapser will use this information to correctly distinguish -# data of individual to-be-row-objects. -sub _resolve_collapse { - my ($self, $as, $as_fq_idx, $rel_chain, $parent_info) = @_; - - # for comprehensible error messages put ourselves at the head of the relationship chain - $rel_chain ||= [ $self->source_name ]; - - # record top-level fully-qualified column index - $as_fq_idx ||= { %$as }; - - my ($my_cols, $rel_cols); - for (keys %$as) { - if ($_ =~ /^ ([^\.]+) \. (.+) /x) { - $rel_cols->{$1}{$2} = 1; - } - else { - $my_cols->{$_} = {}; # important for ||= below - } - } - - my $relinfo; - # run through relationships, collect metadata, inject non-left fk-bridges from - # *INNER-JOINED* children (if any) - for my $rel (keys %$rel_cols) { - my $rel_src = $self->related_source ($rel); - my $inf = $self->relationship_info ($rel); - - $relinfo->{$rel}{is_single} = $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi'; - $relinfo->{$rel}{is_inner} = ( $inf->{attrs}{join_type} || '' ) !~ /^left/i; - $relinfo->{$rel}{rsrc} = $rel_src; - - my $cond = $inf->{cond}; - - if ( - ref $cond eq 'HASH' - and - keys %$cond - and - ! List::Util::first { $_ !~ /^foreign\./ } (keys %$cond) - and - ! List::Util::first { $_ !~ /^self\./ } (values %$cond) - ) { - for my $f (keys %$cond) { - my $s = $cond->{$f}; - $_ =~ s/^ (?: foreign | self ) \.//x for ($f, $s); - $relinfo->{$rel}{fk_map}{$s} = $f; - - $my_cols->{$s} ||= { via_fk => "$rel.$f" } # need to know source from *our* pov - if ($relinfo->{$rel}{is_inner} && defined $rel_cols->{$rel}{$f}); # only if it is inner and in fact selected of course - } - } - } - - # if the parent is already defined, assume all of its related FKs are selected - # (even if they in fact are NOT in the select list). Keep a record of what we - # assumed, and if any such phantom-column becomes part of our own collapser, - # throw everything assumed-from-parent away and replace with the collapser of - # the parent (whatever it may be) - my $assumed_from_parent; - unless ($parent_info->{underdefined}) { - $assumed_from_parent->{columns} = { map - # only add to the list if we do not already select said columns - { ! exists $my_cols->{$_} ? ( $_ => 1 ) : () } - values %{$parent_info->{rel_condition} || {}} - }; - - $my_cols->{$_} = { via_collapse => $parent_info->{collapse_on} } - for keys %{$assumed_from_parent->{columns}}; - } - - # get colinfo for everything - if ($my_cols) { - $my_cols->{$_}{colinfo} = ( - $self->has_column ($_) ? $self->column_info ($_) : undef - ) for keys %$my_cols; - } - - my $collapse_map; - - # try to resolve based on our columns (plus already inserted FK bridges) - if ( - $my_cols - and - my $uset = $self->_unique_column_set ($my_cols) - ) { - # see if the resulting collapser relies on any implied columns, - # and fix stuff up if this is the case - - my $parent_collapser_used; - - if (List::Util::first - { exists $assumed_from_parent->{columns}{$_} } - keys %$uset - ) { - # remove implied stuff from the uset, we will inject the equivalent collapser a bit below - delete @{$uset}{keys %{$assumed_from_parent->{columns}}}; - $parent_collapser_used = 1; - } - - $collapse_map->{-collapse_on} = { - %{ $parent_collapser_used ? $parent_info->{collapse_on} : {} }, - (map - { - my $fqc = join ('.', - @{$rel_chain}[1 .. $#$rel_chain], - ( $my_cols->{$_}{via_fk} || $_ ), - ); - - $fqc => $as_fq_idx->{$fqc}; - } - keys %$uset - ), - }; - } - - # don't know how to collapse - keep descending down 1:1 chains - if - # a related non-LEFT 1:1 is resolvable - its condition will collapse us - # too - unless ($collapse_map->{-collapse_on}) { - my @candidates; - - for my $rel (keys %$relinfo) { - next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner}); - - if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse ( - $rel_cols->{$rel}, - $as_fq_idx, - [ @$rel_chain, $rel ], - { underdefined => 1 } - )) { - push @candidates, $rel_collapse->{-collapse_on}; - } - } - - # get the set with least amount of columns - # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints - # to a single varchar) - if (@candidates) { - ($collapse_map->{-collapse_on}) = sort { keys %$a <=> keys %$b } (@candidates); - } - } - - # Still dont know how to collapse - see if the parent passed us anything - # (i.e. reuse collapser over 1:1) - unless ($collapse_map->{-collapse_on}) { - $collapse_map->{-collapse_on} = $parent_info->{collapse_on} - if $parent_info->{collapser_reusable}; - } - - - # stop descending into children if we were called by a parent for first-pass - # and don't despair if nothing was found (there may be other parallel branches - # to dive into) - if ($parent_info->{underdefined}) { - return $collapse_map->{-collapse_on} ? $collapse_map : undef - } - # nothing down the chain resolved - can't calculate a collapse-map - elsif (! $collapse_map->{-collapse_on}) { - $self->throw_exception ( sprintf - "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns", - $self->source_name, - @$rel_chain > 1 - ? sprintf (' (last member of the %s chain)', join ' -> ', @$rel_chain ) - : '' - , - ); - } - - - # If we got that far - we are collapsable - GREAT! Now go down all children - # a second time, and fill in the rest - - for my $rel (keys %$relinfo) { - - $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse ( - { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) }, - - $as_fq_idx, - - [ @$rel_chain, $rel], - - { - collapse_on => { %{$collapse_map->{-collapse_on}} }, - - rel_condition => $relinfo->{$rel}{fk_map}, - - # if this is a 1:1 our own collapser can be used as a collapse-map - # (regardless of left or not) - collapser_reusable => $relinfo->{$rel}{is_single}, - }, - ); - } - - return $collapse_map; -} - -sub _unique_column_set { - my ($self, $cols) = @_; - - my %unique = $self->unique_constraints; - - # always prefer the PK first, and then shortest constraints first - USET: - for my $set (delete $unique{primary}, sort { @$a <=> @$b } (values %unique) ) { - next unless $set && @$set; - - for (@$set) { - next USET unless ($cols->{$_} && $cols->{$_}{colinfo} && !$cols->{$_}{colinfo}{is_nullable} ); - } - - return { map { $_ => 1 } @$set }; - } - - return undef; -} - -# Takes an arrayref of {as} dbic column aliases and the collapse and select -# attributes from the same $rs (the slector requirement is a temporary -# workaround), and returns a coderef capable of: -# my $me_pref_clps = $coderef->([$rs->cursor->next]) -# Where the $me_pref_clps arrayref is the future argument to -# ::ResultSet::_collapse_result. -# -# $me_pref_clps->[0] is always returned (even if as an empty hash with no -# rowdata), however branches of related data in $me_pref_clps->[1] may be -# pruned short of what was originally requested based on {as}, depending -# on: -# -# * If collapse is requested, a definitive collapse map is calculated for -# every relationship "fold-point", consisting of a set of values (which -# may not even be contained in the future 'me' of said relationship -# (for example a cd.artist_id defines the related inner-joined artist)). -# Thus a definedness check is carried on all collapse-condition values -# and if at least one is undef it is assumed that we are dealing with a -# NULLed right-side of a left-join, so we don't return a related data -# container at all, which implies no related objects -# -# * If we are not collapsing, there is no constraint on having a selector -# uniquely identifying all possible objects, and the user might have very -# well requested a column that just *happens* to be all NULLs. What we do -# in this case is fallback to the old behavior (which is a potential FIXME) -# by always returning a data container, but only filling it with columns -# IFF at least one of them is defined. This way we do not get an object -# with a bunch of has_column_loaded to undef, but at the same time do not -# further relationships based off this "null" object (e.g. in case the user -# deliberately skipped link-table values). I am pretty sure there are some -# tests that codify this behavior, need to find the exact testname. -# -# For an example of this coderef in action (and to see its guts) look at -# t/prefetch/_internals.t -# -# This is a huge performance win, as we call the same code for -# every row returned from the db, thus avoiding repeated method -# lookups when traversing relationships -# -# Also since the coderef is completely stateless (the returned structure is -# always fresh on every new invocation) this is a very good opportunity for -# memoization if further speed improvements are needed -# -# The way we construct this coderef is somewhat fugly, although I am not -# sure if the string eval is *that* bad of an idea. The alternative is to -# have a *very* large number of anon coderefs calling each other in a twisty -# maze, whereas the current result is a nice, smooth, single-pass function. -# In any case - the output of this thing is meticulously micro-tested, so -# any sort of rewrite should be relatively easy -# -sub _mk_row_parser { - my ($self, $as, $with_collapse, $select) = @_; - - my $as_indexed = { map - { $as->[$_] => $_ } - ( 0 .. $#$as ) - }; - - # calculate collapse fold-points if needed - my $collapse_on = do { - # FIXME - # only consider real columns (not functions) during collapse resolution - # this check shouldn't really be here, as fucktards are not supposed to - # alias random crap to existing column names anyway, but still - just in - # case (also saves us from select/as mismatches which need fixing as well...) - - my $plain_as = { %$as_indexed }; - for (keys %$plain_as) { - delete $plain_as->{$_} if ref $select->[$plain_as->{$_}]; - } - $self->_resolve_collapse ($plain_as); - - } if $with_collapse; - - my $perl = $self->__visit_as ($as_indexed, $collapse_on); - my $cref = eval "sub { $perl }" - or die "Oops! _mk_row_parser generated invalid perl:\n$@\n\n$perl\n"; - return $cref; -} - -{ - my $visit_as_dumper; # keep our own DD object around so we don't have to fitz with quoting - - sub __visit_as { - my ($self, $as, $collapse_on, $known_defined) = @_; - $known_defined ||= {}; - - # prepopulate the known defined map with our own collapse value positions - # the rationale is that if an Artist needs column 0 to be uniquely - # identified, and related CDs need columns 0 and 1, by the time we get to - # CDs we already know that column 0 is defined (otherwise there would be - # no related CDs as there is no Artist in the 1st place). So we use this - # index to cut on repetitive defined() checks. - $known_defined->{$_}++ for ( values %{$collapse_on->{-collapse_on} || {}} ); - - my $my_cols = {}; - my $rel_cols; - for (keys %$as) { - if ($_ =~ /^ ([^\.]+) \. (.+) /x) { - $rel_cols->{$1}{$2} = $as->{$_}; - } - else { - $my_cols->{$_} = $as->{$_}; - } - } - - my @relperl; - for my $rel (sort keys %$rel_cols) { - my $rel_node = $self->__visit_as($rel_cols->{$rel}, $collapse_on->{$rel}, {%$known_defined} ); - - my @null_checks; - if ($collapse_on->{$rel}{-collapse_on}) { - @null_checks = map - { "(! defined '__VALPOS__${_}__')" } - ( grep - { ! $known_defined->{$_} } - ( sort - { $a <=> $b } - values %{$collapse_on->{$rel}{-collapse_on}} - ) - ) - ; - } - - if (@null_checks) { - push @relperl, sprintf ( '(%s) ? () : ( %s => %s )', - join (' || ', @null_checks ), - $rel, - $rel_node, - ); - } - else { - push @relperl, "$rel => $rel_node"; - } - } - my $rels = @relperl - ? sprintf ('{ %s }', join (',', @relperl)) - : 'undef' - ; - - my $me = { - map { $_ => "__VALPOS__$my_cols->{$_}__" } (keys %$my_cols) - }; - - my $clps = undef; # funny thing, but this prevents a memory leak, I guess it's Data::Dumper#s fault (mo) - $clps = [ - map { "__VALPOS__${_}__" } ( sort { $a <=> $b } (values %{$collapse_on->{-collapse_on}}) ) - ] if $collapse_on->{-collapse_on}; - - # we actually will be producing functional perl code here, - # thus no second-guessing of what these globals might have - # been set to. DO NOT CHANGE! - $visit_as_dumper ||= do { - require Data::Dumper; - Data::Dumper->new([]) - ->Purity (1) - ->Pad ('') - ->Useqq (0) - ->Terse (1) - ->Quotekeys (1) - ->Deepcopy (1) - ->Deparse (0) - ->Maxdepth (0) - ->Indent (0) - }; - for ($me, $clps) { - $_ = $visit_as_dumper->Values ([$_])->Dump; - } - - unless ($collapse_on->{-collapse_on}) { # we are not collapsing, insert a definedness check on 'me' - $me = sprintf ( '(%s) ? %s : {}', - join (' || ', map { "( defined '__VALPOS__${_}__')" } (sort { $a <=> $b } values %$my_cols) ), - $me, - ); - } - - my @rv_list = ($me, $rels, $clps); - pop @rv_list while ($rv_list[-1] eq 'undef'); # strip trailing undefs - - # change the quoted placeholders to unquoted alias-references - $_ =~ s/ \' __VALPOS__(\d+)__ \' /sprintf ('$_[0][%d]', $1)/gex - for grep { defined $_ } @rv_list; - return sprintf '[%s]', join (',', @rv_list); - } -} - =head2 related_source =over 4 @@ -2432,9 +2042,9 @@ metadata from storage as necessary. This is *deprecated*, and should not be used. It will be removed before 1.0. -=head1 AUTHORS +=head1 AUTHOR AND CONTRIBUTORS -Matt S. Trout +See L and L in DBIx::Class =head1 LICENSE