structure saas with tools

.venv/lib/python3.10/site-packages/google/cloud/bigquery/dbapi/connection.py

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+# Copyright 2017 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
+#
+#     http://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.
+
+"""Connection for the Google BigQuery DB-API."""
+
+import weakref
+
+from google.cloud import bigquery
+from google.cloud.bigquery.dbapi import cursor
+from google.cloud.bigquery.dbapi import _helpers
+
+
+@_helpers.raise_on_closed("Operating on a closed connection.")
+class Connection(object):
+    """DB-API Connection to Google BigQuery.
+
+    Args:
+        client (Optional[google.cloud.bigquery.Client]):
+            A REST API client used to connect to BigQuery. If not passed, a
+            client is created using default options inferred from the environment.
+        bqstorage_client(\
+            Optional[google.cloud.bigquery_storage_v1.BigQueryReadClient] \
+        ):
+            A client that uses the faster BigQuery Storage API to fetch rows from
+            BigQuery. If not passed, it is created using the same credentials
+            as ``client`` (provided that BigQuery Storage dependencies are installed).
+        prefer_bqstorage_client (Optional[bool]):
+            Prefer the BigQuery Storage client over the REST client. If Storage
+            client isn't available, fall back to the REST client. Defaults to
+            ``True``.
+    """
+
+    def __init__(
+        self,
+        client=None,
+        bqstorage_client=None,
+        prefer_bqstorage_client=True,
+    ):
+        if client is None:
+            client = bigquery.Client()
+            self._owns_client = True
+        else:
+            self._owns_client = False
+
+        # A warning is already raised by the BQ Storage client factory factory if
+        # instantiation fails, or if the given BQ Storage client instance is outdated.
+        if not prefer_bqstorage_client:
+            bqstorage_client = None
+            self._owns_bqstorage_client = False
+        elif bqstorage_client is None:
+            bqstorage_client = client._ensure_bqstorage_client()
+            self._owns_bqstorage_client = bqstorage_client is not None
+        else:
+            self._owns_bqstorage_client = False
+            bqstorage_client = client._ensure_bqstorage_client(bqstorage_client)
+
+        self._client = client
+        self._bqstorage_client = bqstorage_client
+
+        self._closed = False
+        self._cursors_created = weakref.WeakSet()
+
+    def close(self):
+        """Close the connection and any cursors created from it.
+
+        Any BigQuery clients explicitly passed to the constructor are *not*
+        closed, only those created by the connection instance itself.
+        """
+        self._closed = True
+
+        if self._owns_client:
+            self._client.close()
+
+        if self._owns_bqstorage_client:
+            # There is no close() on the BQ Storage client itself.
+            self._bqstorage_client._transport.grpc_channel.close()
+
+        for cursor_ in self._cursors_created:
+            if not cursor_._closed:
+                cursor_.close()
+
+    def commit(self):
+        """No-op, but for consistency raise an error if connection is closed."""
+
+    def cursor(self):
+        """Return a new cursor object.
+
+        Returns:
+            google.cloud.bigquery.dbapi.Cursor: A DB-API cursor that uses this connection.
+        """
+        new_cursor = cursor.Cursor(self)
+        self._cursors_created.add(new_cursor)
+        return new_cursor
+
+
+def connect(client=None, bqstorage_client=None, prefer_bqstorage_client=True):
+    """Construct a DB-API connection to Google BigQuery.
+
+    Args:
+        client (Optional[google.cloud.bigquery.Client]):
+            A REST API client used to connect to BigQuery. If not passed, a
+            client is created using default options inferred from the environment.
+        bqstorage_client(\
+            Optional[google.cloud.bigquery_storage_v1.BigQueryReadClient] \
+        ):
+            A client that uses the faster BigQuery Storage API to fetch rows from
+            BigQuery. If not passed, it is created using the same credentials
+            as ``client`` (provided that BigQuery Storage dependencies are installed).
+        prefer_bqstorage_client (Optional[bool]):
+            Prefer the BigQuery Storage client over the REST client. If Storage
+            client isn't available, fall back to the REST client. Defaults to
+            ``True``.
+
+    Returns:
+        google.cloud.bigquery.dbapi.Connection: A new DB-API connection to BigQuery.
+    """
+    return Connection(client, bqstorage_client, prefer_bqstorage_client)