1 files changed, 63 insertions, 0 deletions
diff --git a/webapp/django/db/__init__.py b/webapp/django/db/__init__.py
new file mode 100644
index 0000000000..d15fd3238e
--- /dev/null
+++ b/webapp/django/db/__init__.py
@@ -0,0 +1,63 @@
+import os
+from django.conf import settings
+from django.core import signals
+from django.core.exceptions import ImproperlyConfigured
+from django.utils.functional import curry
+
+__all__ = ('backend', 'connection', 'DatabaseError', 'IntegrityError')
+
+if not settings.DATABASE_ENGINE:
+    settings.DATABASE_ENGINE = 'dummy'
+
+try:
+    # Most of the time, the database backend will be one of the official
+    # backends that ships with Django, so look there first.
+    _import_path = 'django.db.backends.'
+    backend = __import__('%s%s.base' % (_import_path, settings.DATABASE_ENGINE), {}, {}, [''])
+except ImportError, e:
+    # If the import failed, we might be looking for a database backend
+    # distributed external to Django. So we'll try that next.
+    try:
+        _import_path = ''
+        backend = __import__('%s.base' % settings.DATABASE_ENGINE, {}, {}, [''])
+    except ImportError, e_user:
+        # The database backend wasn't found. Display a helpful error message
+        # listing all possible (built-in) database backends.
+        backend_dir = os.path.join(__path__[0], 'backends')
+        try:
+            available_backends = [f for f in os.listdir(backend_dir) if not f.startswith('_') and not f.startswith('.') and not f.endswith('.py') and not f.endswith('.pyc')]
+        except EnvironmentError:
+            available_backends = []
+        available_backends.sort()
+        if settings.DATABASE_ENGINE not in available_backends:
+            raise ImproperlyConfigured, "%r isn't an available database backend. Available options are: %s\nError was: %s" % \
+                (settings.DATABASE_ENGINE, ", ".join(map(repr, available_backends)), e_user)
+        else:
+            raise # If there's some other error, this must be an error in Django itself.
+
+# Convenient aliases for backend bits.
+connection = backend.DatabaseWrapper(**settings.DATABASE_OPTIONS)
+DatabaseError = backend.DatabaseError
+IntegrityError = backend.IntegrityError
+
+# Register an event that closes the database connection
+# when a Django request is finished.
+def close_connection(**kwargs):
+    connection.close()
+signals.request_finished.connect(close_connection)
+
+# Register an event that resets connection.queries
+# when a Django request is started.
+def reset_queries(**kwargs):
+    connection.queries = []
+signals.request_started.connect(reset_queries)
+
+# Register an event that rolls back the connection
+# when a Django request has an exception.
+def _rollback_on_exception(**kwargs):
+    from django.db import transaction
+    try:
+        transaction.rollback_unless_managed()
+    except DatabaseError:
+        pass
+signals.got_request_exception.connect(_rollback_on_exception)