feat: add AppendRowsStream helper to append rows with a BigQueryWriteClient

docs/bigquery_storage_v1beta2/library.rst

@@ -4,3 +4,7 @@ Bigquery Storage v1beta2 API Library
 .. automodule:: google.cloud.bigquery_storage_v1beta2.client
     :members:
     :inherited-members:
+
+.. automodule:: google.cloud.bigquery_storage_v1beta2.writer
+    :members:
+    :inherited-members:

google/cloud/bigquery_storage_v1beta2/__init__.py

@@ -30,10 +30,15 @@ class BigQueryReadClient(client.BigQueryReadClient):
     __doc__ = client.BigQueryReadClient.__doc__
 
 
+class BigQueryWriteClient(client.BigQueryWriteClient):
+    __doc__ = client.BigQueryWriteClient.__doc__
+
+
 __all__ = (
     # google.cloud.bigquery_storage_v1beta2
     "__version__",
     "types",
     # google.cloud.bigquery_storage_v1beta2.client
     "BigQueryReadClient",
+    "BigQueryWriteClient",
 )

google/cloud/bigquery_storage_v1beta2/client.py

@@ -19,12 +19,14 @@
 This is the base from which all interactions with the API occur.
 """
 
-from __future__ import absolute_import
-
 import google.api_core.gapic_v1.method
+import google.api_core.retry
 
 from google.cloud.bigquery_storage_v1 import reader
-from google.cloud.bigquery_storage_v1beta2.services import big_query_read
+from google.cloud.bigquery_storage_v1beta2.services import (
+    big_query_read,
+    big_query_write,
+)
 
 
 _SCOPES = (
@@ -135,3 +137,7 @@ def read_rows(
             offset,
             {"retry": retry, "timeout": timeout, "metadata": metadata},
         )
+
+
+class BigQueryWriteClient(big_query_write.BigQueryWriteClient):
+    __doc__ = big_query_write.BigQueryWriteClient.__doc__

google/cloud/bigquery_storage_v1beta2/exceptions.py

@@ -0,0 +1,17 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+class StreamClosedError(Exception):
+    """Operation not supported while stream is closed."""