feat: update batchmap and mapstream to use Map proto (#200)

Signed-off-by: Sidhant Kohli <sidhant.kohli@gmail.com>
Co-authored-by: Vigith Maurice <vigith@gmail.com>

pynumaflow/batchmapper/_dtypes.py

@@ -4,7 +4,6 @@
 from datetime import datetime
 from typing import TypeVar, Callable, Union, Optional
 from collections.abc import AsyncIterable
-from collections.abc import Awaitable
 
 from pynumaflow._constants import DROP
 
@@ -222,5 +221,9 @@ async def handler(self, datums: AsyncIterable[Datum]) -> BatchResponses:
         pass
 
 
-BatchMapAsyncCallable = Callable[[AsyncIterable[Datum]], Awaitable[BatchResponses]]
+BatchMapAsyncCallable = Callable[[AsyncIterable[Datum]], BatchResponses]
 BatchMapCallable = Union[BatchMapper, BatchMapAsyncCallable]
+
+
+class BatchMapError(Exception):
+    """To Raise an error while executing a BatchMap call"""

pynumaflow/batchmapper/async_server.py

@@ -18,7 +18,7 @@
     MINIMUM_NUMAFLOW_VERSION,
     ContainerType,
 )
-from pynumaflow.proto.batchmapper import batchmap_pb2_grpc
+from pynumaflow.proto.mapper import map_pb2_grpc
 from pynumaflow.shared.server import NumaflowServer, start_async_server
 
 
@@ -103,7 +103,7 @@ async def aexec(self):
         # Create a new async server instance and add the servicer to it
         server = grpc.aio.server(options=self._server_options)
         server.add_insecure_port(self.sock_path)
-        batchmap_pb2_grpc.add_BatchMapServicer_to_server(
+        map_pb2_grpc.add_MapServicer_to_server(
             self.servicer,
             server,
         )

pynumaflow/batchmapper/servicer/async_servicer.py

@@ -5,40 +5,19 @@
 from google.protobuf import empty_pb2 as _empty_pb2
 
 from pynumaflow.batchmapper import Datum
-from pynumaflow.batchmapper._dtypes import BatchMapCallable
-from pynumaflow.proto.batchmapper import batchmap_pb2, batchmap_pb2_grpc
+from pynumaflow.batchmapper._dtypes import BatchMapCallable, BatchMapError
+from pynumaflow.proto.mapper import map_pb2, map_pb2_grpc
 from pynumaflow.shared.asynciter import NonBlockingIterator
 from pynumaflow.shared.server import exit_on_error
 from pynumaflow.types import NumaflowServicerContext
 from pynumaflow._constants import _LOGGER, STREAM_EOF
 
 
-async def datum_generator(
-    request_iterator: AsyncIterable[batchmap_pb2.BatchMapRequest],
-) -> AsyncIterable[Datum]:
-    """
-    This function is used to create an async generator
-    from the gRPC request iterator.
-    It yields a Datum instance for each request received which is then
-    forwarded to the UDF.
-    """
-    async for d in request_iterator:
-        request = Datum(
-            keys=d.keys,
-            value=d.value,
-            event_time=d.event_time.ToDatetime(),
-            watermark=d.watermark.ToDatetime(),
-            headers=dict(d.headers),
-            id=d.id,
-        )
-        yield request
-
-
-class AsyncBatchMapServicer(batchmap_pb2_grpc.BatchMapServicer):
+class AsyncBatchMapServicer(map_pb2_grpc.MapServicer):
     """
     This class is used to create a new grpc Batch Map Servicer instance.
-    It implements the BatchMapServicer interface from the proto
-    batchmap_pb2_grpc.py file.
+    It implements the MapServicer interface from the proto
+    map_pb2_grpc.py file.
     Provides the functionality for the required rpc methods.
     """
 
@@ -49,41 +28,74 @@ def __init__(
         self.background_tasks = set()
         self.__batch_map_handler: BatchMapCallable = handler
 
-    async def BatchMapFn(
+    async def MapFn(
         self,
-        request_iterator: AsyncIterable[batchmap_pb2.BatchMapRequest],
+        request_iterator: AsyncIterable[map_pb2.MapRequest],
         context: NumaflowServicerContext,
-    ) -> batchmap_pb2.BatchMapResponse:
+    ) -> AsyncIterable[map_pb2.MapResponse]:
         """
-        Applies a batch map function to a BatchMapRequest stream in a batching mode.
-        The pascal case function name comes from the proto batchmap_pb2_grpc.py file.
+        Applies a batch map function to a MapRequest stream in a batching mode.
+        The pascal case function name comes from the proto map_pb2_grpc.py file.
         """
-        # Create an async iterator from the request iterator
-        datum_iterator = datum_generator(request_iterator=request_iterator)
-
         try:
-            # invoke the UDF call for batch map
-            responses, request_counter = await self.invoke_batch_map(datum_iterator)
-
-            # If the number of responses received does not align with the request batch size,
-            # we will not be able to process the data correctly.
-            # This should be marked as an error and raised to the user.
-            if len(responses) != request_counter:
-                err_msg = "batchMapFn: mismatch between length of batch requests and responses"
-                raise Exception(err_msg)
-
-            # iterate over the responses received and covert to the required proto format
-            for batch_response in responses:
-                single_req_resp = []
-                for msg in batch_response.messages:
-                    single_req_resp.append(
-                        batchmap_pb2.BatchMapResponse.Result(
-                            keys=msg.keys, value=msg.value, tags=msg.tags
-                        )
+            # The first message to be received should be a valid handshake
+            req = await request_iterator.__anext__()
+            # check if it is a valid handshake req
+            if not (req.handshake and req.handshake.sot):
+                raise BatchMapError("BatchMapFn: expected handshake as the first message")
+            yield map_pb2.MapResponse(handshake=map_pb2.Handshake(sot=True))
+
+            # cur_task is used to track the task (coroutine) processing
+            # the current batch of messages.
+            cur_task = None
+            # iterate of the incoming messages ot the sink
+            async for d in request_iterator:
+                # if we do not have any active task currently processing the batch
+                # we need to create one and call the User function for processing the same.
+                if cur_task is None:
+                    req_queue = NonBlockingIterator()
+                    cur_task = asyncio.create_task(
+                        self.__batch_map_handler(req_queue.read_iterator())
                     )
-
-                # send the response for a given ID back to the stream
-                yield batchmap_pb2.BatchMapResponse(id=batch_response.id, results=single_req_resp)
+                    self.background_tasks.add(cur_task)
+                    cur_task.add_done_callback(self.background_tasks.discard)
+                # when we have end of transmission message, we need to stop the processing the
+                # current batch and wait for the next batch of messages.
+                # We will also wait for the current task to finish processing the current batch.
+                # We mark the current task as None to indicate that we are
+                # ready to process the next batch.
+                if d.status and d.status.eot:
+                    await req_queue.put(STREAM_EOF)
+                    await cur_task
+                    ret = cur_task.result()
+
+                    # iterate over the responses received and covert to the required proto format
+                    for batch_response in ret:
+                        single_req_resp = []
+                        for msg in batch_response.messages:
+                            single_req_resp.append(
+                                map_pb2.MapResponse.Result(
+                                    keys=msg.keys, value=msg.value, tags=msg.tags
+                                )
+                            )
+                        # send the response for a given ID back to the stream
+                        yield map_pb2.MapResponse(id=batch_response.id, results=single_req_resp)
+
+                    # send EOT after each finishing Batch responses
+                    yield map_pb2.MapResponse(status=map_pb2.TransmissionStatus(eot=True))
+                    cur_task = None
+                    continue
+
+                # if we have a valid message, we will add it to the request queue for processing.
+                datum = Datum(
+                    keys=list(d.request.keys),
+                    value=d.request.value,
+                    event_time=d.request.event_time.ToDatetime(),
+                    watermark=d.request.watermark.ToDatetime(),
+                    headers=dict(d.request.headers),
+                    id=d.id,
+                )
+                await req_queue.put(datum)
 
         except BaseException as err:
             _LOGGER.critical("UDFError, re-raising the error", exc_info=True)
@@ -93,42 +105,11 @@ async def BatchMapFn(
             exit_on_error(context, repr(err))
             return
 
-    async def invoke_batch_map(self, datum_iterator: AsyncIterable[Datum]):
-        """
-        # iterate over the incoming requests, and keep sending to the user code
-        # once all messages have been sent, we wait for the responses
-        """
-        # create a message queue to send to the user code
-        niter = NonBlockingIterator()
-        riter = niter.read_iterator()
-        # create a task for invoking the UDF handler
-        task = asyncio.create_task(self.__batch_map_handler(riter))
-        # Save a reference to the result of this function, to avoid a
-        # task disappearing mid-execution.
-        self.background_tasks.add(task)
-        task.add_done_callback(lambda t: self.background_tasks.remove(t))
-
-        req_count = 0
-        # start streaming the messages to the UDF code, and increment the request counter
-        async for datum in datum_iterator:
-            await niter.put(datum)
-            req_count += 1
-
-        # once all messages have been exhausted, send an EOF to indicate end of messages
-        # to the UDF
-        await niter.put(STREAM_EOF)
-
-        # wait for all the responses
-        await task
-
-        # return the result from the UDF, along with the request_counter
-        return task.result(), req_count
-
     async def IsReady(
         self, request: _empty_pb2.Empty, context: NumaflowServicerContext
-    ) -> batchmap_pb2.ReadyResponse:
+    ) -> map_pb2.ReadyResponse:
         """
         IsReady is the heartbeat endpoint for gRPC.
         The pascal case function name comes from the proto batchmap_pb2_grpc.py file.
         """
-        return batchmap_pb2.ReadyResponse(ready=True)
+        return map_pb2.ReadyResponse(ready=True)

pynumaflow/mapstreamer/_dtypes.py

@@ -201,3 +201,7 @@ async def handler(self, keys: list[str], datum: Datum) -> AsyncIterable[Message]
 
 MapStreamAsyncCallable = Callable[[list[str], Datum], AsyncIterable[Message]]
 MapStreamCallable = Union[MapStreamer, MapStreamAsyncCallable]
+
+
+class MapStreamError(Exception):
+    """To Raise an error while executing a MapStream call"""

pynumaflow/mapstreamer/async_server.py

@@ -9,7 +9,7 @@
     ContainerType,
 )
 from pynumaflow.mapstreamer.servicer.async_servicer import AsyncMapStreamServicer
-from pynumaflow.proto.mapstreamer import mapstream_pb2_grpc
+from pynumaflow.proto.mapper import map_pb2_grpc
 
 from pynumaflow._constants import (
     MAP_STREAM_SOCK_PATH,
@@ -122,7 +122,7 @@ async def aexec(self):
         # Create a new async server instance and add the servicer to it
         server = grpc.aio.server(options=self._server_options)
         server.add_insecure_port(self.sock_path)
-        mapstream_pb2_grpc.add_MapStreamServicer_to_server(
+        map_pb2_grpc.add_MapServicer_to_server(
             self.servicer,
             server,
         )

pynumaflow/mapstreamer/servicer/async_servicer.py

@@ -3,18 +3,18 @@
 from google.protobuf import empty_pb2 as _empty_pb2
 
 from pynumaflow.mapstreamer import Datum
-from pynumaflow.mapstreamer._dtypes import MapStreamCallable
-from pynumaflow.proto.mapstreamer import mapstream_pb2_grpc, mapstream_pb2
+from pynumaflow.mapstreamer._dtypes import MapStreamCallable, MapStreamError
+from pynumaflow.proto.mapper import map_pb2_grpc, map_pb2
 from pynumaflow.shared.server import exit_on_error
 from pynumaflow.types import NumaflowServicerContext
 from pynumaflow._constants import _LOGGER
 
 
-class AsyncMapStreamServicer(mapstream_pb2_grpc.MapStreamServicer):
+class AsyncMapStreamServicer(map_pb2_grpc.MapServicer):
     """
     This class is used to create a new grpc Map Stream Servicer instance.
     It implements the SyncMapServicer interface from the proto
-    mapstream_pb2_grpc.py file.
+    map_pb2_grpc.py file.
     Provides the functionality for the required rpc methods.
     """
 
@@ -24,52 +24,58 @@ def __init__(
     ):
         self.__map_stream_handler: MapStreamCallable = handler
 
-    async def MapStreamFn(
+    async def MapFn(
         self,
-        request: mapstream_pb2.MapStreamRequest,
+        request_iterator: AsyncIterable[map_pb2.MapRequest],
         context: NumaflowServicerContext,
-    ) -> AsyncIterable[mapstream_pb2.MapStreamResponse]:
+    ) -> AsyncIterable[map_pb2.MapResponse]:
         """
         Applies a map function to a datum stream in streaming mode.
-        The pascal case function name comes from the proto mapstream_pb2_grpc.py file.
+        The pascal case function name comes from the proto map_pb2_grpc.py file.
         """
-
         try:
-            async for res in self.__invoke_map_stream(
-                list(request.keys),
-                Datum(
-                    keys=list(request.keys),
-                    value=request.value,
-                    event_time=request.event_time.ToDatetime(),
-                    watermark=request.watermark.ToDatetime(),
-                    headers=dict(request.headers),
-                ),
-                context,
-            ):
-                yield mapstream_pb2.MapStreamResponse(result=res)
+            # The first message to be received should be a valid handshake
+            req = await request_iterator.__anext__()
+            # check if it is a valid handshake req
+            if not (req.handshake and req.handshake.sot):
+                raise MapStreamError("MapStreamFn: expected handshake as the first message")
+            yield map_pb2.MapResponse(handshake=map_pb2.Handshake(sot=True))
+
+            # read for each input request
+            async for req in request_iterator:
+                # yield messages as received from the UDF
+                async for res in self.__invoke_map_stream(
+                    list(req.request.keys),
+                    Datum(
+                        keys=list(req.request.keys),
+                        value=req.request.value,
+                        event_time=req.request.event_time.ToDatetime(),
+                        watermark=req.request.watermark.ToDatetime(),
+                        headers=dict(req.request.headers),
+                    ),
+                ):
+                    yield map_pb2.MapResponse(results=[res], id=req.id)
+                # send EOT to indicate end of transmission for a given message
+                yield map_pb2.MapResponse(status=map_pb2.TransmissionStatus(eot=True), id=req.id)
         except BaseException as err:
             _LOGGER.critical("UDFError, re-raising the error", exc_info=True)
             exit_on_error(context, repr(err))
             return
 
-    async def __invoke_map_stream(
-        self, keys: list[str], req: Datum, context: NumaflowServicerContext
-    ):
+    async def __invoke_map_stream(self, keys: list[str], req: Datum):
         try:
+            # Invoke the user handler for map stream
             async for msg in self.__map_stream_handler(keys, req):
-                yield mapstream_pb2.MapStreamResponse.Result(
-                    keys=msg.keys, value=msg.value, tags=msg.tags
-                )
+                yield map_pb2.MapResponse.Result(keys=msg.keys, value=msg.value, tags=msg.tags)
         except BaseException as err:
             _LOGGER.critical("UDFError, re-raising the error", exc_info=True)
-            exit_on_error(context, repr(err))
             raise err
 
     async def IsReady(
         self, request: _empty_pb2.Empty, context: NumaflowServicerContext
-    ) -> mapstream_pb2.ReadyResponse:
+    ) -> map_pb2.ReadyResponse:
         """
         IsReady is the heartbeat endpoint for gRPC.
-        The pascal case function name comes from the proto mapstream_pb2_grpc.py file.
+        The pascal case function name comes from the proto map_pb2_grpc.py file.
         """
-        return mapstream_pb2.ReadyResponse(ready=True)
+        return map_pb2.ReadyResponse(ready=True)