X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBIHacks.pm;h=26f8dcac1f559a252ba5ba3d69627cf32c8d9c46;hb=8d73fcd44e0441f0252744be32bada6816c5ff6b;hp=8a3cb0279ff273c6e23c686cfab15aaca214a439;hpb=eb58c082cf9c35760d8fc199483d38c1d926b2e4;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm index 8a3cb02..26f8dca 100644 --- a/lib/DBIx/Class/Storage/DBIHacks.pm +++ b/lib/DBIx/Class/Storage/DBIHacks.pm @@ -15,7 +15,8 @@ use mro 'c3'; use List::Util 'first'; use Scalar::Util 'blessed'; -use Sub::Name 'subname'; +use DBIx::Class::_Util 'UNRESOLVABLE_CONDITION'; +use SQL::Abstract qw(is_plain_value is_literal_value); use namespace::clean; # @@ -389,7 +390,6 @@ sub _resolve_aliastypes_from_select_args { my $sql_maker = $self->sql_maker; # these are throw away results, do not pollute the bind stack - local $sql_maker->{select_bind}; local $sql_maker->{where_bind}; local $sql_maker->{group_bind}; local $sql_maker->{having_bind}; @@ -429,15 +429,46 @@ sub _resolve_aliastypes_from_select_args { ), ], selecting => [ - $sql_maker->_recurse_fields ($attrs->{select}), + map { ($sql_maker->_recurse_fields($_))[0] } @{$attrs->{select}}, ], ordering => [ map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker), ], }; - # throw away empty chunks - $_ = [ map { $_ || () } @$_ ] for values %$to_scan; + # throw away empty chunks and all 2-value arrayrefs: the thinking is that these are + # bind value specs left in by the sloppy renderer above. It is ok to do this + # at this point, since we are going to end up rewriting this crap anyway + for my $v (values %$to_scan) { + my @nv; + for (@$v) { + next if ( + ! defined $_ + or + ( + ref $_ eq 'ARRAY' + and + ( @$_ == 0 or @$_ == 2 ) + ) + ); + + if (ref $_) { + require Data::Dumper::Concise; + $self->throw_exception("Unexpected ref in scan-plan: " . Data::Dumper::Concise::Dumper($v) ); + } + + push @nv, $_; + } + + $v = \@nv; + } + + # kill all selectors which look like a proper subquery + # this is a sucky heuristic *BUT* - if we get it wrong the query will simply + # fail to run, so we are relatively safe + $to_scan->{selecting} = [ grep { + $_ !~ / \A \s* \( \s* SELECT \s+ .+? \s+ FROM \s+ .+? \) \s* \z /xsi + } @{ $to_scan->{selecting} || [] } ]; # first see if we have any exact matches (qualified or unqualified) for my $type (keys %$to_scan) { @@ -623,9 +654,10 @@ sub _group_over_selection { } $self->throw_exception ( sprintf - 'A required group_by clause could not be constructed automatically due to a complex ' - . 'order_by criteria (%s). Either order_by columns only (no functions) or construct a suitable ' - . 'group_by by hand', + 'Unable to programatically derive a required group_by from the supplied ' + . 'order_by criteria. To proceed either add an explicit group_by, or ' + . 'simplify your order_by to only include plain columns ' + . '(supplied order_by: %s)', join ', ', map { "'$_'" } @$leftovers, ) if $leftovers; @@ -679,6 +711,9 @@ sub _resolve_ident_sources { # for all sources sub _resolve_column_info { my ($self, $ident, $colnames) = @_; + + return {} if $colnames and ! @$colnames; + my $alias2src = $self->_resolve_ident_sources($ident); my (%seen_cols, @auto_colnames); @@ -749,31 +784,9 @@ sub _resolve_column_info { sub _inner_join_to_node { my ($self, $from, $alias) = @_; - # subqueries and other oddness are naturally not supported - return $from if ( - ref $from ne 'ARRAY' - || - @$from <= 1 - || - ref $from->[0] ne 'HASH' - || - ! $from->[0]{-alias} - || - $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do - ); - - # find the current $alias in the $from structure - my $switch_branch; - JOINSCAN: - for my $j (@{$from}[1 .. $#$from]) { - if ($j->[0]{-alias} eq $alias) { - $switch_branch = $j->[0]{-join_path}; - last JOINSCAN; - } - } + my $switch_branch = $self->_find_join_path_to_node($from, $alias); - # something else went quite wrong - return $from unless $switch_branch; + return $from unless @{$switch_branch||[]}; # So it looks like we will have to switch some stuff around. # local() is useless here as we will be leaving the scope @@ -801,6 +814,29 @@ sub _inner_join_to_node { return \@new_from; } +sub _find_join_path_to_node { + my ($self, $from, $target_alias) = @_; + + # subqueries and other oddness are naturally not supported + return undef if ( + ref $from ne 'ARRAY' + || + ref $from->[0] ne 'HASH' + || + ! defined $from->[0]{-alias} + ); + + # no path - the head is the alias + return [] if $from->[0]{-alias} eq $target_alias; + + for my $i (1 .. $#$from) { + return $from->[$i][0]{-join_path} if ( ($from->[$i][0]{-alias}||'') eq $target_alias ); + } + + # something else went quite wrong + return undef; +} + sub _extract_order_criteria { my ($self, $order_by, $sql_maker) = @_; @@ -850,15 +886,15 @@ sub _order_by_is_stable { my ($self, $ident, $order_by, $where) = @_; my @cols = ( - (map { $_->[0] } $self->_extract_order_criteria($order_by)), - $where ? @{$self->_extract_fixed_condition_columns($where)} :(), - ) or return undef; + ( map { $_->[0] } $self->_extract_order_criteria($order_by) ), + ( $where ? keys %{ $self->_extract_fixed_condition_columns($where) } : () ), + ) or return 0; my $colinfo = $self->_resolve_column_info($ident, \@cols); return keys %$colinfo ? $self->_columns_comprise_identifying_set( $colinfo, \@cols ) - : undef + : 0 ; } @@ -874,115 +910,357 @@ sub _columns_comprise_identifying_set { return 1 if $src->_identifying_column_set($_); } - return undef; + return 0; } -# this is almost identical to the above, except it accepts only +# this is almost similar to _order_by_is_stable, except it takes # a single rsrc, and will succeed only if the first portion of the order # by is stable. # returns that portion as a colinfo hashref on success -sub _main_source_order_by_portion_is_stable { - my ($self, $main_rsrc, $order_by, $where) = @_; +sub _extract_colinfo_of_stable_main_source_order_by_portion { + my ($self, $attrs) = @_; - die "Huh... I expect a blessed result_source..." - if ref($main_rsrc) eq 'ARRAY'; + my $nodes = $self->_find_join_path_to_node($attrs->{from}, $attrs->{alias}); + + return unless defined $nodes; my @ord_cols = map { $_->[0] } - ( $self->_extract_order_criteria($order_by) ) + ( $self->_extract_order_criteria($attrs->{order_by}) ) ; return unless @ord_cols; - my $colinfos = $self->_resolve_column_info($main_rsrc); + my $valid_aliases = { map { $_ => 1 } ( + $attrs->{from}[0]{-alias}, + map { values %$_ } @$nodes, + ) }; - for (0 .. $#ord_cols) { - if ( - ! $colinfos->{$ord_cols[$_]} + my $colinfos = $self->_resolve_column_info($attrs->{from}); + + my ($colinfos_to_return, $seen_main_src_cols); + + for my $col (@ord_cols) { + # if order criteria is unresolvable - there is nothing we can do + my $colinfo = $colinfos->{$col} or last; + + # if we reached the end of the allowed aliases - also nothing we can do + last unless $valid_aliases->{$colinfo->{-source_alias}}; + + $colinfos_to_return->{$col} = $colinfo; + + $seen_main_src_cols->{$colinfo->{-colname}} = 1 + if $colinfo->{-source_alias} eq $attrs->{alias}; + } + + # FIXME the condition may be singling out things on its own, so we + # conceivable could come back wi "stable-ordered by nothing" + # not confient enough in the parser yet, so punt for the time being + return unless $seen_main_src_cols; + + my $main_src_fixed_cols_from_cond = [ $attrs->{where} + ? ( + map + { + ( $colinfos->{$_} and $colinfos->{$_}{-source_alias} eq $attrs->{alias} ) + ? $colinfos->{$_}{-colname} + : () + } + keys %{ $self->_extract_fixed_condition_columns($attrs->{where}) } + ) + : () + ]; + + return $attrs->{result_source}->_identifying_column_set([ + keys %$seen_main_src_cols, + @$main_src_fixed_cols_from_cond, + ]) ? $colinfos_to_return : (); +} + +# Attempts to flatten a passed in SQLA condition as much as possible towards +# a plain hashref, *without* altering its semantics. Required by +# create/populate being able to extract definitive conditions from preexisting +# resultset {where} stacks +# +# FIXME - while relatively robust, this is still imperfect, one of the first +# things to tackle with DQ +sub _collapse_cond { + my ($self, $where, $where_is_anded_array) = @_; + + if (! $where) { + return; + } + elsif ($where_is_anded_array or ref $where eq 'HASH') { + + my @pairs; + + my @pieces = $where_is_anded_array ? @$where : $where; + while (@pieces) { + my $chunk = shift @pieces; + + if (ref $chunk eq 'HASH') { + push @pairs, map { [ $_ => $chunk->{$_} ] } sort keys %$chunk; + } + elsif (ref $chunk eq 'ARRAY') { + push @pairs, [ -or => $chunk ] + if @$chunk; + } + elsif ( ! ref $chunk) { + push @pairs, [ $chunk, shift @pieces ]; + } + else { + push @pairs, [ '', $chunk ]; + } + } + + return unless @pairs; + + my @conds = $self->_collapse_cond_unroll_pairs(\@pairs) + or return; + + # Consolidate various @conds back into something more compact + my $fin; + + for my $c (@conds) { + if (ref $c ne 'HASH') { + push @{$fin->{-and}}, $c; + } + else { + for my $col (sort keys %$c) { + if (exists $fin->{$col}) { + my ($l, $r) = ($fin->{$col}, $c->{$col}); + + (ref $_ ne 'ARRAY' or !@$_) and $_ = [ -and => $_ ] for ($l, $r); + + if (@$l and @$r and $l->[0] eq $r->[0] and $l->[0] eq '-and') { + $fin->{$col} = [ -and => map { @$_[1..$#$_] } ($l, $r) ]; + } + else { + $fin->{$col} = [ -and => $fin->{$col}, $c->{$col} ]; + } + } + else { + $fin->{$col} = $c->{$col}; + } + } + } + } + + if ( ref $fin->{-and} eq 'ARRAY' and @{$fin->{-and}} == 1 ) { + my $piece = (delete $fin->{-and})->[0]; + if (ref $piece eq 'ARRAY') { + $fin->{-or} = $fin->{-or} ? [ $piece, $fin->{-or} ] : $piece; + } + elsif (! exists $fin->{''}) { + $fin->{''} = $piece; + } + } + + return $fin; + } + elsif (ref $where eq 'ARRAY') { + my @w = @$where; + + while ( @w and ( + (ref $w[0] eq 'ARRAY' and ! @{$w[0]} ) or - $colinfos->{$ord_cols[$_]}{-result_source} != $main_rsrc - ) { - $#ord_cols = $_ - 1; - last; + (ref $w[0] eq 'HASH' and ! keys %{$w[0]}) + )) { shift @w }; + + return unless @w; + + if ( @w == 1 ) { + return ( ref $w[0] ) + ? $self->_collapse_cond($w[0]) + : { $w[0] => undef } + ; } + elsif ( @w == 2 and ! ref $w[0]) { + if ( ( $w[0]||'' ) =~ /^\-and$/i ) { + return (ref $w[1] eq 'HASH' or ref $w[1] eq 'ARRAY') + ? $self->_collapse_cond($w[1], (ref $w[1] eq 'ARRAY') ) + : $self->throw_exception("Unsupported top-level op/arg pair: [ $w[0] => $w[1] ]") + ; + } + else { + return $self->_collapse_cond({ @w }); + } + } + else { + return { -or => \@w }; + } + } + else { + # not a hash not an array + return { '' => $where }; } - # we just truncated it above - return unless @ord_cols; + die 'should not get here'; +} - my $order_portion_ci = { map { - $colinfos->{$_}{-colname} => $colinfos->{$_}, - $colinfos->{$_}{-fq_colname} => $colinfos->{$_}, - } @ord_cols }; +sub _collapse_cond_unroll_pairs { + my ($self, $pairs) = @_; - # since all we check here are the start of the order_by belonging to the - # top level $rsrc, a present identifying set will mean that the resultset - # is ordered by its leftmost table in a stable manner - # - # RV of _identifying_column_set contains unqualified names only - my $unqualified_idset = $main_rsrc->_identifying_column_set({ - ( $where ? %{ - $self->_resolve_column_info( - $main_rsrc, $self->_extract_fixed_condition_columns($where) - ) - } : () ), - %$order_portion_ci - }) or return; - - my $ret_info; - my %unqualified_idcols_from_order = map { - $order_portion_ci->{$_} ? ( $_ => $order_portion_ci->{$_} ) : () - } @$unqualified_idset; - - # extra optimization - cut the order_by at the end of the identifying set - # (just in case the user was stupid and overlooked the obvious) - for my $i (0 .. $#ord_cols) { - my $col = $ord_cols[$i]; - my $unqualified_colname = $order_portion_ci->{$col}{-colname}; - $ret_info->{$col} = { %{$order_portion_ci->{$col}}, -idx_in_order_subset => $i }; - delete $unqualified_idcols_from_order{$ret_info->{$col}{-colname}}; - - # we didn't reach the end of the identifying portion yet - return $ret_info unless keys %unqualified_idcols_from_order; - } - - die 'How did we get here...'; + my @conds; + + while (@$pairs) { + my ($lhs, $rhs) = @{ shift @$pairs }; + + if ($lhs eq '') { + push @conds, $self->_collapse_cond($rhs); + } + elsif ( $lhs =~ /^\-and$/i ) { + push @conds, $self->_collapse_cond($rhs, (ref $rhs eq 'ARRAY')); + } + elsif ( $lhs =~ /^\-or$/i ) { + push @conds, $self->_collapse_cond( + (ref $rhs eq 'HASH') ? [ map { $_ => $rhs->{$_} } sort keys %$rhs ] : $rhs + ); + } + else { + if (ref $rhs eq 'HASH' and ! keys %$rhs) { + # FIXME - SQLA seems to be doing... nothing...? + } + elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-ident}) { + push @conds, { $lhs => { '=', $rhs } }; + } + elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-value} and is_plain_value $rhs->{-value}) { + push @conds, { $lhs => $rhs->{-value} }; + } + elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}) { + if( is_literal_value $rhs->{'='}) { + push @conds, { $lhs => $rhs }; + } + else { + for my $p ($self->_collapse_cond_unroll_pairs([ [ $lhs => $rhs->{'='} ] ])) { + + # extra sanity check + if (keys %$p > 1) { + require Data::Dumper::Concise; + local $Data::Dumper::Deepcopy = 1; + $self->throw_exception( + "Internal error: unexpected collapse unroll:" + . Data::Dumper::Concise::Dumper { in => { $lhs => $rhs }, out => $p } + ); + } + + my ($l, $r) = %$p; + + push @conds, ( ! length ref $r or is_plain_value($r) ) + ? { $l => $r } + : { $l => { '=' => $r } } + ; + } + } + } + elsif (ref $rhs eq 'ARRAY') { + # some of these conditionals encounter multi-values - roll them out using + # an unshift, which will cause extra looping in the while{} above + if (! @$rhs ) { + push @conds, { $lhs => [] }; + } + elsif ( ($rhs->[0]||'') =~ /^\-(?:and|or)$/i ) { + $self->throw_exception("Value modifier not followed by any values: $lhs => [ $rhs->[0] ] ") + if @$rhs == 1; + + if( $rhs->[0] =~ /^\-and$/i ) { + unshift @$pairs, map { [ $lhs => $_ ] } @{$rhs}[1..$#$rhs]; + } + # if not an AND then it's an OR + elsif(@$rhs == 2) { + unshift @$pairs, [ $lhs => $rhs->[1] ]; + } + else { + push @conds, { $lhs => $rhs }; + } + } + elsif (@$rhs == 1) { + unshift @$pairs, [ $lhs => $rhs->[0] ]; + } + else { + push @conds, { $lhs => $rhs }; + } + } + else { + push @conds, { $lhs => $rhs }; + } + } + } + + return @conds; } -# returns an arrayref of column names which *definitely* have some -# sort of non-nullable equality requested in the given condition -# specification. This is used to figure out if a resultset is -# constrained to a column which is part of a unique constraint, -# which in turn allows us to better predict how ordering will behave -# etc. +# Analyzes a given condition and attempts to extract all columns +# with a definitive fixed-condition criteria. Returns a hashref +# of k/v pairs suitable to be passed to set_columns(), with a +# MAJOR CAVEAT - multi-value (contradictory) equalities are still +# represented as a reference to the UNRESOVABLE_CONDITION constant +# The reason we do this is that some codepaths only care about the +# codition being stable, as opposed to actually making sense +# +# The normal mode is used to figure out if a resultset is constrained +# to a column which is part of a unique constraint, which in turn +# allows us to better predict how ordering will behave etc. +# +# With the optional "consider_nulls" boolean argument, the function +# is instead used to infer inambiguous values from conditions +# (e.g. the inheritance of resultset conditions on new_result) # -# this is a rudimentary, incomplete, and error-prone extractor -# however this is OK - it is conservative, and if we can not find -# something that is in fact there - the stack will recover gracefully -# Also - DQ and the mst it rode in on will save us all RSN!!! +my $undef_marker = \ do{ my $x = 'undef' }; sub _extract_fixed_condition_columns { - my ($self, $where) = @_; + my ($self, $where, $consider_nulls) = @_; + my $where_hash = $self->_collapse_cond($_[1]); - return unless ref $where eq 'HASH'; + my $res = {}; + my ($c, $v); + for $c (keys %$where_hash) { + my $vals; - my @cols; - for my $lhs (keys %$where) { - if ($lhs =~ /^\-and$/i) { - push @cols, ref $where->{$lhs} eq 'ARRAY' - ? ( map { @{ $self->_extract_fixed_condition_columns($_) } } @{$where->{$lhs}} ) - : @{ $self->_extract_fixed_condition_columns($where->{$lhs}) } - ; + if (!defined ($v = $where_hash->{$c}) ) { + $vals->{$undef_marker} = $v if $consider_nulls + } + elsif ( + ref $v eq 'HASH' + and + keys %$v == 1 + ) { + if (exists $v->{-value}) { + if (defined $v->{-value}) { + $vals->{$v->{-value}} = $v->{-value} + } + elsif( $consider_nulls ) { + $vals->{$undef_marker} = $v->{-value}; + } + } + # do not need to check for plain values - _collapse_cond did it for us + elsif(ref $v->{'='} and is_literal_value($v->{'='}) ) { + $vals->{$v->{'='}} = $v->{'='}; + } + } + elsif ( + ! length ref $v + or + is_plain_value ($v) + ) { + $vals->{$v} = $v; + } + elsif (ref $v eq 'ARRAY' and ($v->[0]||'') eq '-and') { + for ( @{$v}[1..$#$v] ) { + my $subval = $self->_extract_fixed_condition_columns({ $c => $_ }, 'consider nulls'); # always fish nulls out on recursion + next unless exists $subval->{$c}; # didn't find anything + $vals->{defined $subval->{$c} ? $subval->{$c} : $undef_marker} = $subval->{$c}; + } } - elsif ($lhs !~ /^\-/) { - my $val = $where->{$lhs}; - push @cols, $lhs if (defined $val and ( - ! ref $val - or - (ref $val eq 'HASH' and keys %$val == 1 and defined $val->{'='}) - )); + if (keys %$vals == 1) { + ($res->{$c}) = (values %$vals) + unless !$consider_nulls and exists $vals->{$undef_marker}; + } + elsif (keys %$vals > 1) { + $res->{$c} = UNRESOLVABLE_CONDITION; } } - return \@cols; + + $res; } 1;