# 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 (keys %{$rs->_resolved_attrs->{collapse}}) {
+ if ($rs->_resolved_attrs->{collapse}) {
my $row = $rs->next;
carp "Query returned more than one row" if $rs->next;
return $row;
my $attrs = $self->_resolved_attrs_copy;
- if (keys %{$attrs->{collapse}}) {
- $self->throw_exception(
- 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
- );
- }
+ $self->throw_exception(
+ 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ ) if $attrs->{collapse};
if ($where) {
if (defined $attrs->{where}) {
}
}
- my @data = $self->result_source->storage->select_single(
+ my $data = [ $self->result_source->storage->select_single(
$attrs->{from}, $attrs->{select},
$attrs->{where}, $attrs
- );
-
- return (@data ? ($self->_construct_object(@data))[0] : undef);
+ )];
+ return undef unless @$data;
+ $self->{stashed_rows} = [ $data ];
+ $self->_construct_objects->[0];
}
sub next {
my ($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 $row;
-}
-
-sub _construct_object {
- my ($self, @row) = @_;
- 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 $self->{_attrs}{record_filter};
- return @new;
-}
+ return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] };
-sub _collapse_result {
- my ($self, $as_proto, $row) = @_;
+ $self->{stashed_objects} = $self->_construct_objects
+ or return undef;
- my @copy = @$row;
-
- # 'foo' => [ undef, 'foo' ]
- # 'foo.bar' => [ 'foo', 'bar' ]
- # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
-
- my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
-
- my %collapse = %{$self->{_attrs}{collapse}||{}};
-
- my @pri_index;
-
- # if we're doing collapsing (has_many prefetch) we need to grab records
- # until the PK changes, so fill @pri_index. if not, we leave it empty so
- # we know we don't have to bother.
-
- # the reason for not using the collapse stuff directly is because if you
- # had for e.g. two artists in a row with no cds, the collapse info for
- # both would be NULL (undef) so you'd lose the second artist
+ return shift @{$self->{stashed_objects}};
+}
- # store just the index so we can check the array positions from the row
- # without having to contruct the full hash
+# Constructs as many objects as it can in one pass while respecting
+# cursor laziness. Several modes of operation:
+#
+# * Always builds everything present in @{$self->{stashed_rows}}
+# * If called with $fetch_all true - pulls everything off the cursor and
+# builds all objects in one pass
+# * If $self->_resolved_attrs->{collapse} is true, checks the order_by
+# and if the resultset is ordered properly by the left side:
+# * Fetches stuff off the cursor until the "master object" changes,
+# and saves the last extra row (if any) in @{$self->{stashed_rows}}
+# OR
+# * Just fetches, and collapses/constructs everything as if $fetch_all
+# was requested (there is no other way to collapse except for an
+# eager cursor)
+# * If no collapse is requested - just get the next row, construct and
+# return
+sub _construct_objects {
+ my ($self, $fetch_all) = @_;
- if (keys %collapse) {
- my %pri = map { ($_ => 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!)
- }
+ 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 SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ $rows = [ @$rows, $cursor->all ];
}
+ elsif (!$attrs->{collapse}) {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ 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}) )
+ ;
- # no need to do an if, it'll be empty if @pri_index is empty anyway
-
- my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
-
- my @const_rows;
+ my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
- do { # no need to check anything at the front, we always want the first row
+ for (0 .. $#ord_cols) {
+ if (
+ ! $colinfos->{$ord_cols[$_]}
+ or
+ $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
+ ) {
+ splice @ord_cols, $_;
+ last;
+ }
+ }
- my %const;
+ # 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 tsable manner
+ (@ord_cols and $rsrc->_identifying_column_set({ map
+ { $colinfos->{$_}{-colname} => $colinfos->{$_} }
+ @ord_cols
+ })) ? 1 : 0;
+ };
- foreach my $this_as (@construct_as) {
- $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
+ if ($attrs->{_ordered_for_collapse}) {
+ push @$rows, do { my @r = $cursor->next; @r ? \@r : () };
}
+ # instead of looping over ->next, use ->all in stealth mode
+ # FIXME - encapsulation breach, got to be a better way
+ elsif (! $cursor->{done}) {
+ push @$rows, $cursor->all;
+ $cursor->{done} = 1;
+ $fetch_all = 1;
+ }
+ }
- push(@const_rows, \%const);
-
- } until ( # no pri_index => no collapse => drop straight out
- !@pri_index
- or
- do { # get another row, stash it, drop out if different PK
+ return undef unless @$rows;
- @copy = $self->cursor->next;
- $self->{stashed_row} = \@copy;
+ 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");
- # last thing in do block, counts as true if anything doesn't match
+ my $infmap = $attrs->{as};
- # check xor defined first for NULL vs. NOT NULL then if one is
- # defined the other must be so check string equality
+ if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) {
+ # construct a much simpler array->hash folder for the one-table cases right here
- grep {
- (defined $pri_vals{$_} ^ defined $copy[$_])
- || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
- } @pri_index;
+ # 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 } );
}
- );
-
- my $alias = $self->{attrs}{alias};
- my $info = [];
-
- my %collapse_pos;
+ }
+ else {
+ eval sprintf (
+ '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows',
+ join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
+ );
+ }
+ }
+ 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 ? () : (
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
+ ($self->{stashed_rows} = []), # where does it stuff excess
+ )); # modify $rows in-place, shrinking/extending as necessary
+
+ $_ = $inflator->($res_class, $rsrc, @$_) for @$rows;
- 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};
- }
- }
+ # CDBI compat stuff
+ if ($attrs->{record_filter}) {
+ $_ = $attrs->{record_filter}->($_) for @$rows;
}
- return $info;
+ return $rows;
}
=head2 result_source
# if we multi-prefetch we group_by something unique, as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
- if ( keys %{$attrs->{collapse}} ) {
+ if ( $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 '
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()");
}
- 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;
+ delete $self->{stashed_rows};
+ delete $self->{stashed_objects};
+
+ if (my $c = $self->get_cache) {
+ return @$c;
}
- $self->set_cache(\@obj) if $self->{attrs}{cache};
+ $self->cursor->reset;
+
+ my $objs = $self->_construct_objects('fetch_all') || [];
- return @obj;
+ $self->set_cache($objs) if $self->{attrs}{cache};
+
+ return @$objs;
}
=head2 reset
sub reset {
my ($self) = @_;
- delete $self->{_attrs} if exists $self->{_attrs};
+ delete $self->{_attrs};
+ delete $self->{stashed_rows};
+ delete $self->{stashed_objects};
+
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
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 _collapse_order_by select _prefetch_selector_range as/;
+ delete $attrs->{$_} for qw/collapse 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);
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 ];
}
}
if $attrs->{select};
# assume all unqualified selectors to apply to the current alias (legacy stuff)
- for (@sel) {
- $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
- }
+ $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
- # disqualify all $alias.col as-bits (collapser mandated)
- for (@as) {
- $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
- }
+ # disqualify all $alias.col as-bits (inflate-map mandated)
+ $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
# de-duplicate the result (remove *identical* select/as pairs)
# and also die on duplicate {as} pointing to different {select}s
}
}
- $attrs->{collapse} ||= {};
- if ($attrs->{prefetch}) {
+ # generate selections based on the prefetch helper
+ my $prefetch;
+ $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
+ if defined $attrs->{prefetch};
+
+ if ($prefetch) {
$self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
if $attrs->{_dark_selector};
- my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
-
- my $prefetch_ordering = [];
+ $attrs->{collapse} = 1;
# this is a separate structure (we don't look in {from} directly)
# as the resolver needs to shift things off the lists to work
}
}
- my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
+ my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
# we need to somehow mark which columns came from prefetch
if (@prefetch) {
push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
+ }
+
+ $attrs->{_single_object_inflation} = ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}};
- push( @{$attrs->{order_by}}, @$prefetch_ordering );
- $attrs->{_collapse_order_by} = \@$prefetch_ordering;
+ # 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;
+ }
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# 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};
Specifies the (zero-based) row number for the first row to be returned, or the
of the first row of the first page if paging is used.
+=head2 software_limit
+
+=over 4
+
+=item Value: (0 | 1)
+
+=back
+
+When combined with L</rows> and/or L</offset> the generated SQL will not
+include any limit dialect stanzas. Instead the entire result will be selected
+as if no limits were specified, and DBIC will perform the limit locally, by
+artificially advancing and finishing the resulting L</cursor>.
+
+This is the recommended way of performing resultset limiting when no sane RDBMS
+implementation is available (e.g.
+L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
+L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
+
=head2 group_by
=over 4
projects / dbsrgits/DBIx-Class.git / blobdiff