__init__.py 文件源码

def create_grpc_channel(target, credentials, ssl_credentials_file=None,
                        grpc_channel_options=[]):
    """Create and return a gRPC channel.

    Args:
      credentials(google.oauth2.credentials.Credentials): OAuth2 credentials.
      ssl_credentials_file(str): Path to SSL credentials.pem file
        (for testing).
      grpc_channel_options([(option_name, option_val)]): gRPC channel options.
    Returns:
      grpc.Channel.
    """
    ssl_credentials = None
    if ssl_credentials_file:
        with open(ssl_credentials_file) as f:
            ssl_credentials = grpc.ssl_channel_credentials(f.read())
    http_request = google.auth.transport.requests.Request()
    # TODO(proppy): figure out if/why we need to force a refresh.
    # if yes, consider remove access token from serialized credentials.
    credentials.refresh(http_request)
    return google.auth.transport.grpc.secure_authorized_channel(
        credentials, http_request, target,
        ssl_credentials=ssl_credentials,
        options=grpc_channel_options)