X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSource%2FRowParser.pm;h=550c9e5b3a6fcb1688593ce36b38df1cdab918ec;hb=571df6765aada245c9882a358cd4269541a178b4;hp=d71ca309ea94467f83e39a3e495d74a956358219;hpb=4e9fc3f33df616fb7340d05e304ff985b9cce9cb;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSource/RowParser.pm b/lib/DBIx/Class/ResultSource/RowParser.pm index d71ca30..550c9e5 100644 --- a/lib/DBIx/Class/ResultSource/RowParser.pm +++ b/lib/DBIx/Class/ResultSource/RowParser.pm @@ -63,11 +63,12 @@ sub _resolve_prefetch { } } -# Takes a selection list and generates a collapse-map representing +# Takes an arrayref 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. +# data of individual to-be-row-objects. See t/resultset/rowparser_internals.t +# for extensive RV examples sub _resolve_collapse { my ($self, $as, $as_fq_idx, $rel_chain, $parent_info, $node_idx_ref) = @_; @@ -270,54 +271,28 @@ sub _resolve_collapse { } # 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. +# attributes from the same $rs (the selector requirement is a temporary +# workaround... I hope), and returns a coderef capable of: +# my $me_pref_clps = $coderef->([$rs->cursor->next/all]) +# Where the $me_pref_clps arrayref is the future argument to inflate_result() # # For an example of this coderef in action (and to see its guts) look at -# t/prefetch/_internals.t +# t/resultset/rowparser_internals.t # -# This is a huge performance win, as we call the same code for -# every row returned from the db, thus avoiding repeated method -# lookups when traversing relationships +# This is a huge performance win, as we call the same code for # every row +# returned from the db, thus avoiding repeated method lookups when traversing +# relationships # # Also since the coderef is completely stateless (the returned structure is # always fresh on every new invocation) this is a very good opportunity for # memoization if further speed improvements are needed # -# The way we construct this coderef is somewhat fugly, although I am not -# sure if the string eval is *that* bad of an idea. The alternative is to -# have a *very* large number of anon coderefs calling each other in a twisty -# maze, whereas the current result is a nice, smooth, single-pass function. +# The way we construct this coderef is somewhat fugly, although the result is +# really worth it. The final coderef does not perform any kind of recursion - +# the entire nested structure constructor is rolled out into a single scope. +# # In any case - the output of this thing is meticulously micro-tested, so -# any sort of rewrite should be relatively easy +# any sort of adjustment/rewrite should be relatively easy (fsvo relatively) # sub _mk_row_parser { my ($self, $args) = @_; @@ -327,8 +302,30 @@ sub _mk_row_parser { ( 0 .. $#{$args->{inflate_map}} ) }; - my ($parser_src); - if ($args->{collapse}) { + my $parser_src; + + # the non-collapsing assembler is easy + # FIXME SUBOPTIMAL there could be a yet faster way to do things here, but + # need to try an actual implementation and benchmark it: + # + # First setup the nested data structure you want for each row + # Then call bind_col() to alias the row fields into the right place in + # the data structure, then to fetch the data do: + # push @rows, dclone($row_data_struct) while ($sth->fetchrow); + # + if (!$args->{collapse}) { + $parser_src = sprintf('$_ = %s for @{$_[0]}', __visit_infmap_simple( + $inflate_index, + { rsrc => $self }, # need the $rsrc to sanity-check inflation map once + )); + + # change the quoted placeholders to unquoted alias-references + $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$_->[$1]"/gex; + } + + # the collapsing parser is more complicated - it needs to keep a lot of state + # + else { my $collapse_map = $self->_resolve_collapse ( # FIXME @@ -337,7 +334,8 @@ sub _mk_row_parser { # alias random crap to existing column names anyway, but still - just in # case # FIXME !!!! - this does not yet deal with unbalanced selectors correctly - # (it is now trivial as the attrs specify where things go out of sync) + # (it is now trivial as the attrs specify where things go out of sync + # needs MOAR tests) { map { ref $args->{selection}[$inflate_index->{$_}] ? () : ( $_ => $inflate_index->{$_} ) } keys %$inflate_index @@ -389,24 +387,16 @@ sub _mk_row_parser { ### END STRING EVAL EOS + # !!! note - different var than the one above # change the quoted placeholders to unquoted alias-references $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$cur_row->[$1]"/gex; $parser_src =~ s/ \' \xFF__IDVALPOS__(\d+)__\xFF \' /"\$cur_row_ids[$1]"/gex; } - else { - $parser_src = sprintf('$_ = %s for @{$_[0]}', __visit_infmap_simple( - $inflate_index, { rsrc => $self }), # need the $rsrc to determine left-ness - ); - - # change the quoted placeholders to unquoted alias-references - # !!! note - different var than the one above - $parser_src =~ s/ \' \xFF__VALPOS__(\d+)__\xFF \' /"\$_->[$1]"/gex; - } - $parser_src; } +# the simple non-collapsing nested structure recursor sub __visit_infmap_simple { my ($val_idx, $args) = @_; @@ -423,18 +413,18 @@ sub __visit_infmap_simple { my @relperl; for my $rel (sort keys %$rel_cols) { - my $rel_rsrc = __get_related_source($args->{rsrc}, $rel, $rel_cols->{$rel}); - + # DISABLEPRUNE #my $optional = $args->{is_optional}; #$optional ||= ($args->{rsrc}->relationship_info($rel)->{attrs}{join_type} || '') =~ /^left/i; push @relperl, join ' => ', perlstring($rel), __visit_infmap_simple($rel_cols->{$rel}, { - non_top => 1, + rsrc => __get_related_source($args->{rsrc}, $rel, $rel_cols->{$rel}), + # DISABLEPRUNE + #non_top => 1, #is_optional => $optional, - rsrc => $rel_rsrc, }); - # FIXME SUBOPTIMAL - disabled to satisfy t/resultset/inflate_result_api.t + # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t #if ($optional and my @branch_null_checks = map # { "(! defined '\xFF__VALPOS__${_}__\xFF')" } # sort { $a <=> $b } values %{$rel_cols->{$rel}} @@ -458,6 +448,7 @@ sub __visit_infmap_simple { ); } +# the collapsing nested structure recursor sub __visit_infmap_collapse { my ($val_idx, $collapse_map, $parent_info) = @_; @@ -512,6 +503,7 @@ sub __visit_infmap_collapse { ); } + # DISABLEPRUNE #my $known_defined = { %{ $parent_info->{known_defined} || {} } }; #$known_defined->{$_}++ for @{$collapse_map->{-node_id}}; @@ -524,10 +516,11 @@ sub __visit_infmap_collapse { node_idx => $collapse_map->{-node_index}, sequenced_node_id => $sequenced_node_id, relname => $rel, + # DISABLEPRUNE #known_defined => $known_defined, }); - # FIXME SUBOPTIMAL - disabled to satisfy t/resultset/inflate_result_api.t + # FIXME SUBOPTIMAL DISABLEPRUNE - disabled to satisfy t/resultset/inflate_result_api.t #if ($collapse_map->{$rel}{-is_optional} and my @null_checks = map # { "(! defined '\xFF__IDVALPOS__${_}__\xFF')" } # sort { $a <=> $b } grep @@ -575,7 +568,7 @@ sub __visit_dump { ($dumper_obj ||= do { require Data::Dumper; Data::Dumper->new([]) - ->Useperl (1) + ->Useperl (0) ->Purity (1) ->Pad ('') ->Useqq (0)