Added delete option to database storage.

venv/Lib/site-packages/grpc/_compression.py

@@ -0,0 +1,55 @@
+# Copyright 2019 The gRPC authors.
+#
+# 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.
+
+from grpc._cython import cygrpc
+
+NoCompression = cygrpc.CompressionAlgorithm.none
+Deflate = cygrpc.CompressionAlgorithm.deflate
+Gzip = cygrpc.CompressionAlgorithm.gzip
+
+_METADATA_STRING_MAPPING = {
+    NoCompression: 'identity',
+    Deflate: 'deflate',
+    Gzip: 'gzip',
+}
+
+
+def _compression_algorithm_to_metadata_value(compression):
+    return _METADATA_STRING_MAPPING[compression]
+
+
+def compression_algorithm_to_metadata(compression):
+    return (cygrpc.GRPC_COMPRESSION_REQUEST_ALGORITHM_MD_KEY,
+            _compression_algorithm_to_metadata_value(compression))
+
+
+def create_channel_option(compression):
+    return ((cygrpc.GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM,
+             int(compression)),) if compression else ()
+
+
+def augment_metadata(metadata, compression):
+    if not metadata and not compression:
+        return None
+    base_metadata = tuple(metadata) if metadata else ()
+    compression_metadata = (
+        compression_algorithm_to_metadata(compression),) if compression else ()
+    return base_metadata + compression_metadata
+
+
+__all__ = (
+    "NoCompression",
+    "Deflate",
+    "Gzip",
+)