Added a no_cache override feature plus testcase. Useful in times of memory...

Added a no_cache override feature plus testcase. Useful in times of memory crisis coupled with annoyingly slow lookups of small data.

modules/Bio/EnsEMBL/DBSQL/BaseAdaptor.pm

@@ -752,7 +752,7 @@ sub last_insert_id {
 
 sub _id_cache {
   my ($self) = @_;
-  return if $self->db()->no_cache();
+  return if $self->db()->no_cache() && !$self->ignore_cache_override;
   if(! exists $self->{_id_cache}) {
     $self->{_id_cache} = $self->_build_id_cache();
   }
@@ -774,6 +774,21 @@ sub _no_id_cache {
   return 0;
 }
 
+=head2 ignore_cache_override
+
+    Description : Method to interfere with no_cache directive from Registry on
+                  a per adaptor basis. This method should be called after new()
+                  in order to trigger the _build_id_cache at first query.                  
+    Example     : $adaptor->ignore_cache_override(1);              
+    Returntype  : Boolean
+=cut
+
+sub ignore_cache_override {
+    my $self = shift;
+    $self->{'_override'} = shift if(@_);
+    unless (defined($self->{'_override'})) {return}
+    return $self->{'_override'}; 
+}
 
 #_tables
 #

modules/t/fullIdCaching.t

@@ -74,6 +74,15 @@ sub BEGIN {
   isnt($adaptor->fetch_all_by_dbID_list([$gene_ids->[0]])->[0], $cached_obj, 'Checking two objects are no longer the same as the cache is off');
   $adaptor->db()->no_cache(0);
   
+  # Negating no_cache
+  $cached_obj = $adaptor->fetch_by_dbID($gene_ids->[0]);
+  $adaptor->db()->no_cache(1);
+  $adaptor->ignore_cache_override(1);
+  is($adaptor->fetch_by_dbID($gene_ids->[0]), $cached_obj, 'Checking no_cache can be ignored.');
+  $adaptor->db()->no_cache(0);
+  $adaptor->ignore_cache_override(0);
+  
+  
   #hit seq region cache & check we clear that one out as well
   $adaptor->fetch_all_by_Slice($genes->[0]->slice());
   $adaptor->clear_cache();