- proof of concept

1 files changed, 26 insertions, 2 deletions

diff --git a/lib/sqlalchemy/orm/unitofwork.py b/lib/sqlalchemy/orm/unitofwork.py
index 71e61827b..8df24e95a 100644
--- a/lib/sqlalchemy/orm/unitofwork.py
+++ b/lib/sqlalchemy/orm/unitofwork.py
@@ -16,6 +16,7 @@ organizes them in order of dependency, and executes.
 from .. import util, event
 from ..util import topological
 from . import attributes, persistence, util as orm_util
+import itertools
 
 
 def track_cascade_events(descriptor, prop):
@@ -379,14 +380,37 @@ class UOWTransaction(object):
         execute() method has succeeded and the transaction has been committed.
 
         """
+        if not self.states:
+            return
+
         states = set(self.states)
         isdel = set(
             s for (s, (isdelete, listonly)) in self.states.items()
             if isdelete
         )
         other = states.difference(isdel)
-        self.session._remove_newly_deleted(isdel)
-        self.session._register_newly_persistent(other)
+        if isdel:
+            self.session._remove_newly_deleted(isdel)
+        if other:
+            self.session._register_newly_persistent(other)
+
+    def bulk_save(self, objects):
+        for (base_mapper, in_session), states in itertools.groupby(
+                (attributes.instance_state(obj) for obj in objects),
+                lambda state:
+                (
+                    state.mapper.base_mapper,
+                    state.key is self.session.hash_key
+                )):
+
+            persistence.save_obj(
+                base_mapper, list(states), self, bookkeeping=in_session)
+
+            if in_session:
+                self.states.update(
+                    (state, (False, False))
+                    for state in states
+                )
 
 
 class IterateMappersMixin(object):