| # Copyright 2017 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. |
| """API metadata conversion utilities.""" |
| |
| import collections |
| |
| _Metadatum = collections.namedtuple('_Metadatum', ('key', 'value',)) |
| |
| |
| def _beta_metadatum(key, value): |
| beta_key = key if isinstance(key, (bytes,)) else key.encode('ascii') |
| beta_value = value if isinstance(value, (bytes,)) else value.encode('ascii') |
| return _Metadatum(beta_key, beta_value) |
| |
| |
| def _metadatum(beta_key, beta_value): |
| key = beta_key if isinstance(beta_key, (str,)) else beta_key.decode('utf8') |
| if isinstance(beta_value, (str,)) or key[-4:] == '-bin': |
| value = beta_value |
| else: |
| value = beta_value.decode('utf8') |
| return _Metadatum(key, value) |
| |
| |
| def beta(metadata): |
| if metadata is None: |
| return () |
| else: |
| return tuple(_beta_metadatum(key, value) for key, value in metadata) |
| |
| |
| def unbeta(beta_metadata): |
| if beta_metadata is None: |
| return () |
| else: |
| return tuple( |
| _metadatum(beta_key, beta_value) |
| for beta_key, beta_value in beta_metadata) |