[svn r74] make a subclass of db_pool that uses tpool.Proxy instead of saranwrap. Unit tests for all possible combinations thereof.

eventlet/db_pool.py

@@ -33,12 +33,15 @@ class DatabaseConnector(object):
     """\
 @brief This is an object which will maintain a collection of database
 connection pools keyed on host,databasename"""
-    def __init__(self, module, credentials, min_size = 0, max_size = 4, *args, **kwargs):
+    def __init__(self, module, credentials, min_size = 0, max_size = 4, conn_pool=None, *args, **kwargs):
         """\
         @brief constructor
         @param min_size the minimum size of a child pool.
         @param max_size the maximum size of a child pool."""
         assert(module)
+        self._conn_pool_class = conn_pool
+        if self._conn_pool_class is None:
+            self._conn_pool_class = ConnectionPool
         self._module = module
         self._min_size = min_size
         self._max_size = max_size
@@ -60,33 +63,35 @@ connection pools keyed on host,databasename"""
             new_kwargs['db'] = dbname
             new_kwargs['host'] = host
             new_kwargs.update(self.credentials_for(host))
-            dbpool = ConnectionPool(self._module, self._min_size, self._max_size, *self._args, **new_kwargs)
+            dbpool = self._conn_pool_class(self._module, self._min_size, self._max_size, *self._args, **new_kwargs)
             self._databases[key] = dbpool
 
         return self._databases[key]
 
-
-class ConnectionPool(Pool):
-    """A pool which gives out saranwrapped database connections from a pool
-    """
-    def __init__(self, module, min_size = 0, max_size = 4, *args, **kwargs):
-        assert(module)
-        self._module = module
+class BaseConnectionPool(Pool):
+    # *TODO: we need to expire and close connections if they've been
+    # idle for a while, so that system-wide connection count doesn't
+    # monotonically increase forever
+    def __init__(self, db_module, min_size = 0, max_size = 4, *args, **kwargs):
+        assert(db_module)
+        self._db_module = db_module
         self._args = args
         self._kwargs = kwargs
-        super(ConnectionPool, self).__init__(min_size, max_size)
+        super(BaseConnectionPool, self).__init__(min_size, max_size)
 
-    def create(self):
-        return saranwrap.wrap(self._module).connect(*self._args, **self._kwargs)
+    def get(self):
+        # wrap the connection for easier use
+        conn = super(BaseConnectionPool, self).get()
+        return PooledConnectionWrapper(conn, self)
 
     def put(self, conn):
         # rollback any uncommitted changes, so that the next client
-        # has a clean slate.  This also pokes the process to see if
+        # has a clean slate.  This also pokes the connection to see if
         # it's dead or None
         try:
             conn.rollback()
         except AttributeError, e:
-            # this means it's already been destroyed
+            # this means it's already been destroyed, so we don't need to print anything
             conn = None
         except:
             # we don't care what the exception was, we just know the
@@ -104,14 +109,32 @@ class ConnectionPool(Pool):
                 conn = None
                 
         if conn is not None:
-            super(ConnectionPool, self).put(conn)
+            super(BaseConnectionPool, self).put(conn)
         else:
             self.current_size -= 1
+    
 
-    def get(self):
-        # wrap the connection for easier use
-        conn = super(ConnectionPool, self).get()
-        return PooledConnectionWrapper(conn, self)
+class SaranwrappedConnectionPool(BaseConnectionPool):
+    """A pool which gives out saranwrapped database connections from a pool
+    """
+    def create(self):
+        return saranwrap.wrap(self._db_module).connect(*self._args, **self._kwargs)
+
+class TpooledConnectionPool(BaseConnectionPool):
+    """A pool which gives out tpool.Proxy-based database connections from a pool.
+    """
+    def create(self):
+        from eventlet import tpool
+        try:
+            # *FIX: this is a huge hack that will probably only work for MySQLdb
+            autowrap = (self._db_module.cursors.DictCursor,)
+        except:
+            autowrap = ()
+        return tpool.Proxy(self._db_module.connect(*self._args, **self._kwargs),
+                           autowrap=autowrap)
+
+# default connection pool is the tpool one
+ConnectionPool = TpooledConnectionPool
 
 
 class GenericConnectionWrapper(object):
@@ -188,4 +211,3 @@ class PooledConnectionWrapper(GenericConnectionWrapper):
     
     def __del__(self):
         self.close()
-

eventlet/db_pool_test.py

@@ -79,9 +79,6 @@ class TestDBConnectionPool(DBTester):
         self.pool.put(self.connection)
         super(TestDBConnectionPool, self).tearDown()
 
-    def create_pool(self, max_items = 1):
-        return db_pool.ConnectionPool(self._dbmodule, 0, max_items, **self._auth)
-
     def assert_cursor_works(self, cursor):
         cursor.execute("show full processlist")
         rows = cursor.fetchall()
@@ -253,7 +250,17 @@ class TestDBConnectionPool(DBTester):
         results.sort()
         self.assertEqual([1, 2], results)
 
-class TestMysqlConnectionPool(TestDBConnectionPool, unittest.TestCase):
+
+class TestTpoolConnectionPool(TestDBConnectionPool):
+    def create_pool(self, max_items = 1):
+        return db_pool.TpooledConnectionPool(self._dbmodule, 0, max_items, **self._auth)
+
+
+class TestSaranwrapConnectionPool(TestDBConnectionPool):
+    def create_pool(self, max_items = 1):
+        return db_pool.SaranwrappedConnectionPool(self._dbmodule, 0, max_items, **self._auth)
+
+class TestMysqlConnectionPool(object):
     def setUp(self):
         import MySQLdb
         self._dbmodule = MySQLdb
@@ -286,6 +293,12 @@ class TestMysqlConnectionPool(TestDBConnectionPool, unittest.TestCase):
         db.close()
         del db
 
+class TestMysqlTpool(TestMysqlConnectionPool, TestTpoolConnectionPool, unittest.TestCase):
+    pass
+
+class TestMysqlSaranwrap(TestMysqlConnectionPool, TestSaranwrapConnectionPool, unittest.TestCase):
+    pass
+
 
 if __name__ == '__main__':
     unittest.main()