[IMP] api, models: _write performances on import

Followup from the previous commit: before this, _write takes 32% of
total runtime, of which 13.7% is ultimately assignable to add_todo.

Turns out for the test case we mostly keep adding records to recorsets
where they're already present, so the 13.7% of runtime in add_todo are
mostly spent creating orderedsets (11.17) then converting those back
into recordsets (1.75%) with some time spent creating lists and
appending records (already present) in them.

Checking if the records are already present before merging them in
decreases add_todo's runtime cost to 0.5%, and ultimately _write to
20%.

As many of the ignorable calls were merging a singleton or an empty
recorset into the parent recordset, optimising for these cases was
added to BaseModel's <= and >=.

1 files changed, 5 insertions, 1 deletions

diff --git a/odoo/api.py b/odoo/api.py
index 688b301cf02..22b82d17147 100644
--- a/odoo/api.py
+++ b/odoo/api.py
@@ -955,7 +955,11 @@ class Environment(Mapping):
         recs_list = self.all.todo.setdefault(field, [])
         for i, recs in enumerate(recs_list):
             if recs.env == records.env:
-                recs_list[i] |= records
+                # only add records if not already in the recordset, much much
+                # cheaper in case recs is big and records is a singleton
+                # already present
+                if not records <= recs:
+                    recs_list[i] |= records
                 break
         else:
             recs_list.append(records)