use strict;
package Tangram::Type::Array::FromMany;
use Tangram::Type::Abstract::Array;
use vars qw(@ISA);
@ISA = qw( Tangram::Type::Abstract::Array );
use Carp;
sub reschema
{
my ($self, $members, $class, $schema) = @_;
foreach my $member (keys %$members)
{
my $def = $members->{$member};
unless (ref($def))
{
# XXX - not reached by test suite
$def = { class => $def };
$members->{$member} = $def;
}
$def->{table} ||= $schema->{normalize}->($def->{class} . "_$member", 'tablename');
$def->{coll} ||= 'coll';
$def->{item} ||= 'item';
$def->{slot} ||= 'slot';
}
return keys %$members;
}
sub get_save_closures
{
my ($self, $storage, $obj, $def, $id) = @_;
my ($table, $cc, $ic, $sc) = @{ $def }{ qw( table coll item slot ) };
my $ne = sub { shift() != shift() };
my $eid = $storage->{export_id}->($id);
my $modify = sub
{
my ($slot, $item) = @_;
my $item_id = $storage->export_object($item)
|| croak "element at $slot has no id";
$storage->sql_do(
"UPDATE\n $table\nSET\n $ic = $item_id\nWHERE\n $cc = $eid AND\n $sc = $slot");
};
my $add = sub
{
my ($slot, $item) = @_;
my $item_id = $storage->export_object($item);
$storage->sql_do(
"INSERT INTO $table ($cc, $ic, $sc)\n VALUES ($eid, $item_id, $slot)");
};
my $remove = sub
{
my ($new_size) = @_;
$storage->sql_do(
"DELETE FROM\n $table\nWHERE\n $cc = $eid AND\n $sc >= $new_size");
};
return ($ne, $modify, $add, $remove);
}
sub erase
{
my ($self, $storage, $obj, $members, $coll_id) = @_;
$coll_id = $storage->{export_id}->($coll_id);
foreach my $member (keys %$members)
{
my $def = $members->{$member};
my $table = $def->{table} || $def->{class} . "_$member";
my $coll_col = $def->{coll} || 'coll';
my $sql = "DELETE FROM\n $table\nWHERE\n $coll_col = $coll_id";
if ($def->{aggreg})
{
my @content = @{ $obj->{$member} };
$storage->sql_do($sql);
$storage->erase( @content ) ;
}
else
{
$storage->sql_do($sql);
}
}
}
sub cursor
{
my ($self, $def, $storage, $obj, $member) = @_;
my $cursor = Tangram::Cursor::Coll->new($storage, $def->{class}, $storage->{db});
my $coll_id = $storage->export_object($obj);
my $coll_tid = $storage->alloc_table;
my $table = $def->{table};
my $item_tid = $cursor->{TARGET}->object->root_table;
my $coll_col = $def->{coll};
my $item_col = $def->{item};
my $slot_col = $def->{slot};
$cursor->{-coll_tid} = $coll_tid;
$cursor->{-coll_cols} = "t$coll_tid.$slot_col";
$cursor->{-coll_from} = "$table t$coll_tid";
$cursor->{-coll_where} = "t$coll_tid.$coll_col = $coll_id AND t$coll_tid.$item_col = t$item_tid.$storage->{schema}{sql}{id_col}";
$cursor->{-no_skip_read} = 1;
return $cursor;
}
sub remote_expr
{
my ($self, $obj, $tid) = @_;
Tangram::Expr::Coll::FromMany->new($obj, $self);
}
# XXX - not reached by test suite
sub query_expr
{
my ($self, $obj, $members, $tid) = @_;
map { Tangram::Expr::Coll::FromMany->new($obj, $_); } values %$members;
}
sub prefetch
{
my ($self, $storage, $def, $coll, $class, $member, $filter) = @_;
my $ritem = $storage->remote($def->{class});
# first retrieve the collection-side ids of all objects satisfying $filter
# empty the corresponding prefetch array
my $ids = $storage->my_select_data( cols => [ $coll->{id} ], filter => $filter );
my $prefetch = $storage->{PREFETCH}{$class}{$member} ||= {}; # weakref
while (my ($id) = $ids->fetchrow)
{
$prefetch->{$id} = []
}
undef $ids;
# now fetch the items
my $cursor = Tangram::Cursor->new($storage, $ritem, $storage->{db});
my $includes = $coll->{$member}->includes($ritem);
# also retrieve collection-side id and index of elmt in sequence
$cursor->retrieve($coll->{id},
Tangram::Type::Number->expr("t$includes->{link_tid}.$def->{slot}") );
$cursor->select($filter ? $filter & $includes : $includes);
while (my $item = $cursor->current)
{
my ($coll_id, $slot) = $cursor->residue;
$prefetch->{$coll_id}[$slot] = $item;
$cursor->next;
}
return $prefetch;
}
$Tangram::Schema::TYPES{array} = Tangram::Type::Array::FromMany->new;
#---------------------------------------------------------------------
# Tangram::Type::Array::FromMany->coldefs($cols, $members, $schema, $class, $tables)
#
# Setup column mappings for many to many unordered mappings (link
# table with integer category)
#---------------------------------------------------------------------
sub coldefs
{
my ($self, $cols, $members, $schema, $class, $tables) = @_;
foreach my $member (values %$members)
{
my $COLS = $tables->{ $member->{table} }{COLS} ||= { };
$COLS->{$member->{coll}} = $schema->{sql}{id};
$COLS->{$member->{item}} = $schema->{sql}{id};
$COLS->{$member->{slot}} = "INT $schema->{sql}{default_null}";
}
}
1;