Implementing Table.exists().

This corresponds to the GetTable method in the table
service.

gcloud_bigtable/cluster.py

@@ -199,6 +199,15 @@ def project_id(self):
         """
         return self._client.project_id
 
+    @property
+    def credentials(self):
+        """Getter for cluster's credentials.
+
+        :rtype: :class:`oauth2client.client.OAuth2Credentials`
+        :returns: The credentials stored on the cluster's client.
+        """
+        return self._client.credentials
+
     @property
     def name(self):
         """Cluster name used in requests.
@@ -250,7 +259,7 @@ def reload(self, timeout_seconds=TIMEOUT_SECONDS):
                                 If not passed, defaults to ``TIMEOUT_SECONDS``.
         """
         request_pb = messages_pb2.GetClusterRequest(name=self.name)
-        stub = make_stub(self.client._credentials, CLUSTER_STUB_FACTORY,
+        stub = make_stub(self.credentials, CLUSTER_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.GetCluster.async(request_pb, timeout_seconds)
@@ -278,7 +287,7 @@ def operation_finished(self, timeout_seconds=TIMEOUT_SECONDS):
         operation_name = ('operations/' + self.name +
                           '/operations/%d' % (self._operation_id,))
         request_pb = operations_pb2.GetOperationRequest(name=operation_name)
-        stub = make_stub(self.client._credentials, OPERATIONS_STUB_FACTORY,
+        stub = make_stub(self.credentials, OPERATIONS_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.GetOperation.async(request_pb, timeout_seconds)
@@ -315,7 +324,7 @@ def create(self, timeout_seconds=TIMEOUT_SECONDS):
                                 If not passed, defaults to ``TIMEOUT_SECONDS``.
         """
         request_pb = _prepare_create_request(self)
-        stub = make_stub(self.client._credentials, CLUSTER_STUB_FACTORY,
+        stub = make_stub(self.credentials, CLUSTER_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.CreateCluster.async(request_pb, timeout_seconds)
@@ -350,7 +359,7 @@ def update(self, timeout_seconds=TIMEOUT_SECONDS):
             display_name=self.display_name,
             serve_nodes=self.serve_nodes,
         )
-        stub = make_stub(self.client._credentials, CLUSTER_STUB_FACTORY,
+        stub = make_stub(self.credentials, CLUSTER_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.UpdateCluster.async(request_pb, timeout_seconds)
@@ -369,7 +378,7 @@ def delete(self, timeout_seconds=TIMEOUT_SECONDS):
                                 If not passed, defaults to ``TIMEOUT_SECONDS``.
         """
         request_pb = messages_pb2.DeleteClusterRequest(name=self.name)
-        stub = make_stub(self.client._credentials, CLUSTER_STUB_FACTORY,
+        stub = make_stub(self.credentials, CLUSTER_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.DeleteCluster.async(request_pb, timeout_seconds)
@@ -384,7 +393,7 @@ def undelete(self, timeout_seconds=TIMEOUT_SECONDS):
                                 If not passed, defaults to ``TIMEOUT_SECONDS``.
         """
         request_pb = messages_pb2.UndeleteClusterRequest(name=self.name)
-        stub = make_stub(self.client._credentials, CLUSTER_STUB_FACTORY,
+        stub = make_stub(self.credentials, CLUSTER_STUB_FACTORY,
                          CLUSTER_ADMIN_HOST, CLUSTER_ADMIN_PORT)
         with stub:
             response = stub.UndeleteCluster.async(request_pb, timeout_seconds)

gcloud_bigtable/table.py

@@ -15,9 +15,40 @@
 """User friendly container for Google Cloud Bigtable Table."""
 
 
+from gcloud_bigtable._generated import (
+    bigtable_table_service_messages_pb2 as messages_pb2)
+from gcloud_bigtable._generated import bigtable_table_service_pb2
+from gcloud_bigtable.connection import TIMEOUT_SECONDS
+from gcloud_bigtable.connection import make_stub
+
+
+TABLE_STUB_FACTORY = (bigtable_table_service_pb2.
+                      early_adopter_create_BigtableTableService_stub)
+TABLE_ADMIN_HOST = 'bigtabletableadmin.googleapis.com'
+"""Table Admin API request host."""
+TABLE_ADMIN_PORT = 443
+"""Table Admin API request port."""
+
+
 class Table(object):
     """Representation of a Google Cloud Bigtable Table.
 
+    .. note::
+
+        We don't define any properties on a table other than the name. As
+        the proto says, in a request:
+
+          "The `name` field of the Table and all of its ColumnFamilies must
+           be left blank, and will be populated in the response."
+
+        This leaves only the ``current_operation`` and ``granularity``
+        fields. The ``current_operation`` is only used for responses while
+        ``granularity`` is an enum with only one value.
+
+    We can use a :class:`Table` to:
+
+    * Check if it :meth:`Table.exists`
+
     :type table_id: string
     :param table_id: The ID of the table.
 
@@ -38,6 +69,15 @@ def cluster(self):
         """
         return self._cluster
 
+    @property
+    def credentials(self):
+        """Getter for table's credentials.
+
+        :rtype: :class:`oauth2client.client.OAuth2Credentials`
+        :returns: The credentials stored on the table's client.
+        """
+        return self._cluster.credentials
+
     @property
     def name(self):
         """Table name used in requests.
@@ -53,3 +93,24 @@ def name(self):
         :returns: The table name.
         """
         return self.cluster.name + '/tables/' + self.table_id
+
+    def exists(self, timeout_seconds=TIMEOUT_SECONDS):
+        """Reload the metadata for this table.
+
+        :type timeout_seconds: integer
+        :param timeout_seconds: Number of seconds for request time-out.
+                                If not passed, defaults to ``TIMEOUT_SECONDS``.
+
+        :rtype: boolean
+        :returns: Boolean indicating if this table exists. If it does not
+                  exist, an exception will be thrown by the API call.
+        """
+        request_pb = messages_pb2.GetTableRequest(name=self.name)
+        stub = make_stub(self.credentials, TABLE_STUB_FACTORY,
+                         TABLE_ADMIN_HOST, TABLE_ADMIN_PORT)
+        with stub:
+            response = stub.GetTable.async(request_pb, timeout_seconds)
+            # We expect a `._generated.bigtable_table_data_pb2.Table`
+            response.result()
+
+        return True

gcloud_bigtable/test_table.py

@@ -13,13 +13,32 @@
 # limitations under the License.
 
 
-import unittest2
+from gcloud_bigtable._grpc_mocks import GRPCMockTestMixin
 
 
+PROJECT_ID = 'project-id'
 TABLE_ID = 'table-id'
 
 
-class TestTable(unittest2.TestCase):
+class TestTable(GRPCMockTestMixin):
+
+    @classmethod
+    def setUpClass(cls):
+        from gcloud_bigtable import client
+        from gcloud_bigtable import table as MUT
+        cls._MUT = MUT
+        cls._STUB_SCOPES = [client.DATA_SCOPE]
+        cls._STUB_FACTORY_NAME = 'TABLE_STUB_FACTORY'
+        cls._STUB_HOST = MUT.TABLE_ADMIN_HOST
+        cls._STUB_PORT = MUT.TABLE_ADMIN_PORT
+
+    @classmethod
+    def tearDownClass(cls):
+        del cls._MUT
+        del cls._STUB_SCOPES
+        del cls._STUB_FACTORY_NAME
+        del cls._STUB_HOST
+        del cls._STUB_PORT
 
     def _getTargetClass(self):
         from gcloud_bigtable.table import Table
@@ -46,6 +65,36 @@ def test_name_property(self):
         expected_name = cluster_name + '/tables/' + TABLE_ID
         self.assertEqual(table.name, expected_name)
 
+    def test_exists(self):
+        from gcloud_bigtable._generated import (
+            bigtable_table_service_messages_pb2 as messages_pb2)
+
+        zone = 'zone'
+        cluster_id = 'cluster-id'
+
+        # Create request_pb
+        table_name = ('projects/' + PROJECT_ID + '/zones/' + zone +
+                      '/clusters/' + cluster_id + '/tables/' + TABLE_ID)
+        request_pb = messages_pb2.GetTableRequest(name=table_name)
+
+        # Create response_pb
+        response_pb = None
+
+        # Create expected_result.
+        expected_result = True
+
+        # We must create the cluster with the client passed in.
+        TEST_CASE = self
+
+        def result_method(client):
+            cluster = client.cluster(zone, cluster_id)
+            table = TEST_CASE._makeOne(TABLE_ID, cluster)
+            return table.exists()
+
+        self._grpc_client_test_helper('GetTable', result_method,
+                                      request_pb, response_pb, expected_result,
+                                      PROJECT_ID)
+
 
 class _Cluster(object):