Implementing HappyBase Connection.__del__.

This makes sure to close a connection when a connection object is
destroyed.

This required updating our test cluster stubs to have a client
which could be stop()-ed.

gcloud_bigtable/happybase/connection.py

@@ -173,6 +173,8 @@ def __init__(self, host=DEFAULT_HOST, port=DEFAULT_PORT, timeout=None,
         if autoconnect:
             self.open()
 
+        self._initialized = True
+
     def open(self):
         """Open the underlying transport to Cloud Bigtable.
 
@@ -191,6 +193,15 @@ def close(self):
         """
         self._cluster.client.stop()
 
+    def __del__(self):
+        try:
+            self._initialized
+        except AttributeError:
+            # Failure from constructor
+            return
+        else:
+            self.close()
+
     def table(self, name, use_prefix=True):
         """Table factory.
 

gcloud_bigtable/happybase/test_connection.py

@@ -81,12 +81,10 @@ def _makeOne(self, *args, **kwargs):
 
     def test_constructor_defaults(self):
         cluster = _Cluster()  # Avoid implicit environ check.
-        # autoconnect=True is default, so we need a valid client
-        cluster.client = client = _Client()
-        self.assertEqual(client.start_calls, 0)
+        self.assertEqual(cluster.client.start_calls, 0)
         connection = self._makeOne(cluster=cluster)
-        self.assertEqual(client.start_calls, 1)
-        self.assertEqual(client.stop_calls, 0)
+        self.assertEqual(cluster.client.start_calls, 1)
+        self.assertEqual(cluster.client.stop_calls, 0)
 
         self.assertEqual(connection._cluster, cluster)
         self.assertEqual(connection.table_prefix, None)
@@ -103,7 +101,7 @@ def test_constructor_missing_cluster(self):
         from gcloud_bigtable._testing import _Monkey
         from gcloud_bigtable.happybase import connection as MUT
 
-        cluster = object()
+        cluster = _Cluster()
         timeout = object()
         mock_get_cluster = _MockCalled(cluster)
         with _Monkey(MUT, _get_cluster=mock_get_cluster):
@@ -119,7 +117,7 @@ def test_constructor_explicit(self):
         timeout = object()
         table_prefix = 'table-prefix'
         table_prefix_separator = 'sep'
-        cluster_copy = object()
+        cluster_copy = _Cluster()
         cluster = _Cluster(cluster_copy)
 
         connection = self._makeOne(
@@ -168,21 +166,36 @@ def test_constructor_with_protocol(self):
 
     def test_open(self):
         cluster = _Cluster()  # Avoid implicit environ check.
-        cluster.client = client = _Client()
         connection = self._makeOne(autoconnect=False, cluster=cluster)
-        self.assertEqual(client.start_calls, 0)
+        self.assertEqual(cluster.client.start_calls, 0)
         connection.open()
-        self.assertEqual(client.start_calls, 1)
-        self.assertEqual(client.stop_calls, 0)
+        self.assertEqual(cluster.client.start_calls, 1)
+        self.assertEqual(cluster.client.stop_calls, 0)
 
     def test_close(self):
         cluster = _Cluster()  # Avoid implicit environ check.
-        cluster.client = client = _Client()
         connection = self._makeOne(autoconnect=False, cluster=cluster)
-        self.assertEqual(client.stop_calls, 0)
+        self.assertEqual(cluster.client.stop_calls, 0)
         connection.close()
-        self.assertEqual(client.stop_calls, 1)
-        self.assertEqual(client.start_calls, 0)
+        self.assertEqual(cluster.client.stop_calls, 1)
+        self.assertEqual(cluster.client.start_calls, 0)
+
+    def test___del__good_initialization(self):
+        cluster = _Cluster()  # Avoid implicit environ check.
+        connection = self._makeOne(autoconnect=False, cluster=cluster)
+        self.assertEqual(cluster.client.stop_calls, 0)
+        connection.__del__()
+        self.assertEqual(cluster.client.stop_calls, 1)
+
+    def test___del__bad_initialization(self):
+        cluster = _Cluster()  # Avoid implicit environ check.
+        connection = self._makeOne(autoconnect=False, cluster=cluster)
+        # Fake that initialization failed.
+        del connection._initialized
+
+        self.assertEqual(cluster.client.stop_calls, 0)
+        connection.__del__()
+        self.assertEqual(cluster.client.stop_calls, 0)
 
     def test_table(self):
         cluster = _Cluster()  # Avoid implicit environ check.
@@ -277,7 +290,8 @@ class _Cluster(object):
 
     def __init__(self, *copies):
         self.copies = list(copies)
-        self.client = None
+        # Included to support Connection.__del__
+        self.client = _Client()
 
     def copy(self):
         if self.copies:

gcloud_bigtable/happybase/test_pool.py

@@ -31,7 +31,7 @@ def test_constructor_defaults(self):
         from gcloud_bigtable.happybase.connection import Connection
 
         size = 11
-        cluster_copy = object()
+        cluster_copy = _Cluster()
         all_copies = [cluster_copy] * size
         cluster = _Cluster(*all_copies)  # Avoid implicit environ check.
         pool = self._makeOne(size, cluster=cluster)
@@ -77,9 +77,9 @@ def open(self):
                 self._open_called = True
 
         # First make sure the custom Connection class does as expected.
-        cluster_copy1 = object()
-        cluster_copy2 = object()
-        cluster_copy3 = object()
+        cluster_copy1 = _Cluster()
+        cluster_copy2 = _Cluster()
+        cluster_copy3 = _Cluster()
         cluster = _Cluster(cluster_copy1, cluster_copy2, cluster_copy3)
         connection = ConnectionWithOpen(autoconnect=False, cluster=cluster)
         self.assertFalse(connection._open_called)
@@ -105,7 +105,7 @@ def test_constructor_infers_cluster(self):
         from gcloud_bigtable.happybase import pool as MUT
 
         size = 1
-        cluster_copy = object()
+        cluster_copy = _Cluster()
         all_copies = [cluster_copy] * size
         cluster = _Cluster(*all_copies)
 
@@ -144,10 +144,21 @@ def test_connection(self):
             pool.connection(timeout=timeout)
 
 
+class _Client(object):
+
+    def __init__(self):
+        self.stop_calls = 0
+
+    def stop(self):
+        self.stop_calls += 1
+
+
 class _Cluster(object):
 
     def __init__(self, *copies):
         self.copies = list(copies)
+        # Included to support Connection.__del__
+        self.client = _Client()
 
     def copy(self):
         if self.copies: