From 9bdcc71733105a49636f74a99130112ef96d0bce Mon Sep 17 00:00:00 2001
From: Vishvananda Ishaya <vishvananda@gmail.com>
Date: Fri, 21 Jan 2011 15:48:10 -0800
Subject: wrap sqlalchemy exceptions in a generic error

---
 nova/db/api.py                |  1 -
 nova/db/sqlalchemy/session.py |  3 +++
 nova/exception.py             | 18 ++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

(limited to 'nova')

diff --git a/nova/db/api.py b/nova/db/api.py
index f9d561587..8afe74eea 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -71,7 +71,6 @@ class NoMoreTargets(exception.Error):
     """No more available blades"""
     pass
 
-
 ###################
 
 
diff --git a/nova/db/sqlalchemy/session.py b/nova/db/sqlalchemy/session.py
index c3876c02a..dc885f138 100644
--- a/nova/db/sqlalchemy/session.py
+++ b/nova/db/sqlalchemy/session.py
@@ -22,6 +22,7 @@ Session Handling for SQLAlchemy backend
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
+from nova import exception
 from nova import flags
 
 FLAGS = flags.FLAGS
@@ -43,4 +44,6 @@ def get_session(autocommit=True, expire_on_commit=False):
                                 autocommit=autocommit,
                                 expire_on_commit=expire_on_commit))
     session = _MAKER()
+    session.query = exception.wrap_db_error(session.query)
+    session.flush = exception.wrap_db_error(session.flush)
     return session
diff --git a/nova/exception.py b/nova/exception.py
index ecd814e5d..f36ffaee1 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -80,6 +80,24 @@ class TimeoutException(Error):
     pass
 
 
+class DBError(Error):
+    """Wraps an implementation specific exception"""
+    def __init__(self, inner_exception):
+        self.inner_exception = inner_exception
+        super(DBError, self).__init__(str(inner_exception))
+
+
+def wrap_db_error(f):
+    def _wrap(*args, **kwargs):
+        try:
+            return f(*args, **kwargs)
+        except Exception, e:
+            LOG.exception(_('DB exception wrapped'))
+            raise DBError(e)
+    return _wrap
+    _wrap.func_name = f.func_name
+
+
 def wrap_exception(f):
     def _wrap(*args, **kw):
         try:
-- 
cgit