reactive-grpc 0.0.2
Python reactive gRPC support
License: MIT
Keywords: reactive reactive-programming grpc protobuf

|build status|

reactive-grpc
=============

A simple gRPC bridge to reactive streams.

Example: Given the following Protocol buffers definition:

::

    syntax = "proto3";

    package rxgrpc.test;

    service TestService {
      rpc GetOneToOne(TestRequest) returns (TestResponse) {}
      rpc GetOneToStream(TestRequest) returns (stream TestResponse) {}
      rpc GetStreamToOne(stream TestRequest) returns (TestResponse) {}
      rpc GetStreamToStream(stream TestRequest) returns (stream TestResponse) {}
    }

    message TestRequest {
      string message = 1;
    }

    message TestResponse {
      string message = 1;
    }

and a simple Servicer class:

.. code:: python

    from test.proto.test_pb2_grpc import TestServiceServicer
    from test.proto import test_pb2


    class _Servicer(TestServiceServicer):
        def GetOneToOne(self, request: test_pb2.TestRequest, context):
            return test_pb2.TestResponse(message='response: {}'.format(request.message))

        def GetOneToStream(self, request, context):
            for i in range(3):
                yield test_pb2.TestResponse(message='response {}: {}'.format(i, request.message))

        def GetStreamToOne(self, request_iterator, context):
            return test_pb2.TestResponse(
                message='response: {}'.format(
                    ', '.join(map(lambda d: d.message, request_iterator))
                )
            )

        def GetStreamToStream(self, request_iterator, context):
            yield from map(
                lambda d: test_pb2.TestResponse(message='response: {}'.format(d.message)),
                request_iterator
            )

A simple gRPC reactive server where request messages are transformed can
be created as follows:

.. code:: python

    from test.proto import test_pb2_grpc, test_pb2
    from rxgrpc import server, mappers
    from rx import operators
    from test.proto.test_pb2_grpc import TestServiceServicer


    class _Servicer(TestServiceServicer):
        # ...
        pass


    workers = 3
    rx_server = server.create_server(test_pb2, workers)
    test_pb2_grpc.add_TestServiceServicer_to_server(_Servicer(), rx_server)
    rx_server.add_insecure_port('[::]:50051')

    def _transform_message(m: test_pb2.TestRequest) -> test_pb2.TestRequest:
        return test_pb2.TestRequest(message='TRANSFORMED {}'.format(m.message))

    rx_server.set_grpc_observable(
        rx_server.grpc_pipe(
            operators.map(mappers.grpc_invocation_map(_transform_message)),
            method_name='/rxgrpc.test.TestService/GetOneToOne'),
        method_name='/rxgrpc.test.TestService/GetOneToOne'
    )

    rx_server.start()

Here it is an example of a filter for a streaming input:

.. code:: python

    from rxgrpc import operators
    from test.proto import test_pb2


    def _filter_message(m: test_pb2.TestRequest) -> test_pb2.TestRequest:
        return bool(int(m.message[-1]) % 2)

    server = ...
    server.set_grpc_observable(
        server.grpc_pipe(
            operators.filter(_filter_message),
            method_name='/rxgrpc.test.TestService/GetStreamToOne'),
        method_name='/rxgrpc.test.TestService/GetStreamToOne'
    )

.. |build status| image:: https://img.shields.io/travis/fcracker79/reactive-grpc/master.svg?style=flat-square
   :target: https://travis-ci.org/fcracker79/reactive-grpc