_compression.py
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# 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",
)