merged 0.2 branch into trunk; 0.1 now in sqlalchemy/branches/rel_0_1

1 files changed, 46 insertions, 0 deletions

diff --git a/lib/sqlalchemy/mods/threadlocal.py b/lib/sqlalchemy/mods/threadlocal.py
new file mode 100644
index 000000000..b67329612
--- /dev/null
+++ b/lib/sqlalchemy/mods/threadlocal.py
@@ -0,0 +1,46 @@
+from sqlalchemy import util, engine, mapper
+from sqlalchemy.ext.sessioncontext import SessionContext
+import sqlalchemy.ext.assignmapper as assignmapper
+from sqlalchemy.orm.mapper import global_extensions
+from sqlalchemy.orm.session import Session
+import sqlalchemy
+import sys, types
+
+"""this plugin installs thread-local behavior at the Engine and Session level.
+
+The default Engine strategy will be "threadlocal", producing TLocalEngine instances for create_engine by default.
+With this engine, connect() method will return the same connection on the same thread, if it is already checked out
+from the pool.  this greatly helps functions that call multiple statements to be able to easily use just one connection
+without explicit "close" statements on result handles.
+
+on the Session side, module-level methods will be installed within the objectstore module, such as flush(), delete(), etc.
+which call this method on the thread-local session.
+
+Note: this mod creates a global, thread-local session context named sqlalchemy.objectstore. All mappers created
+while this mod is installed will reference this global context when creating new mapped object instances.
+"""
+
+class Objectstore(SessionContext):
+    def __getattr__(self, key):
+        return getattr(self.current, key)
+    def get_session(self):
+        return self.current
+
+def assign_mapper(class_, *args, **kwargs):
+    assignmapper.assign_mapper(objectstore, class_, *args, **kwargs)
+
+def _mapper_extension():
+    return SessionContext._get_mapper_extension(objectstore)
+
+objectstore = Objectstore(Session)
+def install_plugin():
+    sqlalchemy.objectstore = objectstore
+    global_extensions.append(_mapper_extension)
+    engine.default_strategy = 'threadlocal'
+    sqlalchemy.assign_mapper = assign_mapper
+
+def uninstall_plugin():
+    engine.default_strategy = 'plain'
+    global_extensions.remove(_mapper_extension)
+
+install_plugin()