1 files changed, 33 insertions, 2 deletions
diff --git a/django/db/transaction.py b/django/db/transaction.py
index cd27cf6044..55fad9e457 100644
--- a/django/db/transaction.py
+++ b/django/db/transaction.py
@@ -19,7 +19,7 @@ except ImportError:
 try:
     from functools import wraps
 except ImportError:
-    from django.utils.functional import wraps  # Python 2.3, 2.4 fallback. 
+    from django.utils.functional import wraps  # Python 2.3, 2.4 fallback.
 from django.db import connection
 from django.conf import settings
 
@@ -30,9 +30,10 @@ class TransactionManagementError(Exception):
     """
     pass
 
-# The state is a dictionary of lists. The key to the dict is the current
+# The states are dictionaries of lists. The key to the dict is the current
 # thread and the list is handled as a stack of values.
 state = {}
+savepoint_state = {}
 
 # The dirty flag is set by *_unless_managed functions to denote that the
 # code under transaction management has changed things to require a
@@ -164,6 +165,36 @@ def rollback():
     connection._rollback()
     set_clean()
 
+def savepoint():
+    """
+    Creates a savepoint (if supported and required by the backend) inside the
+    current transaction. Returns an identifier for the savepoint that will be
+    used for the subsequent rollback or commit.
+    """
+    thread_ident = thread.get_ident()
+    if thread_ident in savepoint_state:
+        savepoint_state[thread_ident].append(None)
+    else:
+        savepoint_state[thread_ident] = [None]
+    tid = str(thread_ident).replace('-', '')
+    sid = "s%s_x%d" % (tid, len(savepoint_state[thread_ident]))
+    connection._savepoint(sid)
+    return sid
+
+def savepoint_rollback(sid):
+    """
+    Rolls back the most recent savepoint (if one exists). Does nothing if
+    savepoints are not supported.
+    """
+    connection._savepoint_rollback(sid)
+
+def savepoint_commit(sid):
+    """
+    Commits the most recent savepoint (if one exists). Does nothing if
+    savepoints are not supported.
+    """
+    connection._savepoint_commit(sid)
+
 ##############
 # DECORATORS #
 ##############