Add async version of durabletask client

.github/workflows/pr-validation.yml

@@ -28,7 +28,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest
+        pip install flake8 pytest pytest-cov pytest-asyncio
         pip install -r requirements.txt
     - name: Lint with flake8
       run: |

dev-requirements.txt

@@ -1 +1 @@
-grpcio-tools==1.62.3 # 1.62.X is the latest version before protobuf 1.26.X is used which has breaking changes for Python
+grpcio-tools==1.62.3 # 1.62.X is the latest version before protobuf 1.26.X is used which has breaking changes for Python # supports protobuf 6.x and aligns with generated code

durabletask/aio/__init__.py

@@ -0,0 +1,5 @@
+from .client import AsyncTaskHubGrpcClient
+
+__all__ = [
+    "AsyncTaskHubGrpcClient",
+]

durabletask/aio/client.py

@@ -0,0 +1,170 @@
+# Copyright (c) The Dapr Authors.
+# Licensed under the MIT License.
+
+import logging
+import uuid
+from datetime import datetime
+from typing import Any, Optional, Sequence, Union
+
+import grpc
+from google.protobuf import wrappers_pb2
+
+import durabletask.internal.helpers as helpers
+import durabletask.internal.orchestrator_service_pb2 as pb
+import durabletask.internal.orchestrator_service_pb2_grpc as stubs
+import durabletask.internal.shared as shared
+from durabletask.aio.internal.shared import get_grpc_aio_channel, ClientInterceptor
+from durabletask import task
+from durabletask.client import OrchestrationState, OrchestrationStatus, new_orchestration_state, TInput, TOutput
+from durabletask.aio.internal.grpc_interceptor import DefaultClientInterceptorImpl
+
+
+class AsyncTaskHubGrpcClient:
+
+    def __init__(self, *,
+                 host_address: Optional[str] = None,
+                 metadata: Optional[list[tuple[str, str]]] = None,
+                 log_handler: Optional[logging.Handler] = None,
+                 log_formatter: Optional[logging.Formatter] = None,
+                 secure_channel: bool = False,
+                 interceptors: Optional[Sequence[ClientInterceptor]] = None):
+
+        if interceptors is not None:
+            interceptors = list(interceptors)
+            if metadata is not None:
+                interceptors.append(DefaultClientInterceptorImpl(metadata))
+        elif metadata is not None:
+            interceptors = [DefaultClientInterceptorImpl(metadata)]
+        else:
+            interceptors = None
+
+        channel = get_grpc_aio_channel(
+            host_address=host_address,
+            secure_channel=secure_channel,
+            interceptors=interceptors
+        )
+        self._channel = channel
+        self._stub = stubs.TaskHubSidecarServiceStub(channel)
+        self._logger = shared.get_logger("client", log_handler, log_formatter)
+
+    async def aclose(self):
+        await self._channel.close()
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        await self.aclose()
+        return False
+
+    async def schedule_new_orchestration(self, orchestrator: Union[task.Orchestrator[TInput, TOutput], str], *,
+                                         input: Optional[TInput] = None,
+                                         instance_id: Optional[str] = None,
+                                         start_at: Optional[datetime] = None,
+                                         reuse_id_policy: Optional[pb.OrchestrationIdReusePolicy] = None) -> str:
+
+        name = orchestrator if isinstance(orchestrator, str) else task.get_name(orchestrator)
+
+        req = pb.CreateInstanceRequest(
+            name=name,
+            instanceId=instance_id if instance_id else uuid.uuid4().hex,
+            input=wrappers_pb2.StringValue(value=shared.to_json(input)) if input is not None else None,
+            scheduledStartTimestamp=helpers.new_timestamp(start_at) if start_at else None,
+            version=helpers.get_string_value(None),
+            orchestrationIdReusePolicy=reuse_id_policy,
+        )
+
+        self._logger.info(f"Starting new '{name}' instance with ID = '{req.instanceId}'.")
+        res: pb.CreateInstanceResponse = await self._stub.StartInstance(req)
+        return res.instanceId
+
+    async def get_orchestration_state(self, instance_id: str, *, fetch_payloads: bool = True) -> Optional[OrchestrationState]:
+        req = pb.GetInstanceRequest(instanceId=instance_id, getInputsAndOutputs=fetch_payloads)
+        res: pb.GetInstanceResponse = await self._stub.GetInstance(req)
+        return new_orchestration_state(req.instanceId, res)
+
+    async def wait_for_orchestration_start(self, instance_id: str, *,
+                                           fetch_payloads: bool = False,
+                                           timeout: int = 0) -> Optional[OrchestrationState]:
+        req = pb.GetInstanceRequest(instanceId=instance_id, getInputsAndOutputs=fetch_payloads)
+        try:
+            grpc_timeout = None if timeout == 0 else timeout
+            self._logger.info(
+                f"Waiting {'indefinitely' if timeout == 0 else f'up to {timeout}s'} for instance '{instance_id}' to start.")
+            res: pb.GetInstanceResponse = await self._stub.WaitForInstanceStart(req, timeout=grpc_timeout)
+            return new_orchestration_state(req.instanceId, res)
+        except grpc.RpcError as rpc_error:
+            if rpc_error.code() == grpc.StatusCode.DEADLINE_EXCEEDED:  # type: ignore
+                # Replace gRPC error with the built-in TimeoutError
+                raise TimeoutError("Timed-out waiting for the orchestration to start")
+            else:
+                raise
+
+    async def wait_for_orchestration_completion(self, instance_id: str, *,
+                                                fetch_payloads: bool = True,
+                                                timeout: int = 0) -> Optional[OrchestrationState]:
+        req = pb.GetInstanceRequest(instanceId=instance_id, getInputsAndOutputs=fetch_payloads)
+        try:
+            grpc_timeout = None if timeout == 0 else timeout
+            self._logger.info(
+                f"Waiting {'indefinitely' if timeout == 0 else f'up to {timeout}s'} for instance '{instance_id}' to complete.")
+            res: pb.GetInstanceResponse = await self._stub.WaitForInstanceCompletion(req, timeout=grpc_timeout)
+            state = new_orchestration_state(req.instanceId, res)
+            if not state:
+                return None
+
+            if state.runtime_status == OrchestrationStatus.FAILED and state.failure_details is not None:
+                details = state.failure_details
+                self._logger.info(f"Instance '{instance_id}' failed: [{details.error_type}] {details.message}")
+            elif state.runtime_status == OrchestrationStatus.TERMINATED:
+                self._logger.info(f"Instance '{instance_id}' was terminated.")
+            elif state.runtime_status == OrchestrationStatus.COMPLETED:
+                self._logger.info(f"Instance '{instance_id}' completed.")
+
+            return state
+        except grpc.RpcError as rpc_error:
+            if rpc_error.code() == grpc.StatusCode.DEADLINE_EXCEEDED:  # type: ignore
+                # Replace gRPC error with the built-in TimeoutError
+                raise TimeoutError("Timed-out waiting for the orchestration to complete")
+            else:
+                raise
+
+    async def raise_orchestration_event(
+            self,
+            instance_id: str,
+            event_name: str,
+            *,
+            data: Optional[Any] = None):
+        req = pb.RaiseEventRequest(
+            instanceId=instance_id,
+            name=event_name,
+            input=wrappers_pb2.StringValue(value=shared.to_json(data)) if data else None)
+
+        self._logger.info(f"Raising event '{event_name}' for instance '{instance_id}'.")
+        await self._stub.RaiseEvent(req)
+
+    async def terminate_orchestration(self, instance_id: str, *,
+                                      output: Optional[Any] = None,
+                                      recursive: bool = True):
+        req = pb.TerminateRequest(
+            instanceId=instance_id,
+            output=wrappers_pb2.StringValue(value=shared.to_json(output)) if output else None,
+            recursive=recursive)
+
+        self._logger.info(f"Terminating instance '{instance_id}'.")
+        await self._stub.TerminateInstance(req)
+
+    async def suspend_orchestration(self, instance_id: str):
+        req = pb.SuspendRequest(instanceId=instance_id)
+        self._logger.info(f"Suspending instance '{instance_id}'.")
+        await self._stub.SuspendInstance(req)
+
+    async def resume_orchestration(self, instance_id: str):
+        req = pb.ResumeRequest(instanceId=instance_id)
+        self._logger.info(f"Resuming instance '{instance_id}'.")
+        await self._stub.ResumeInstance(req)
+
+    async def purge_orchestration(self, instance_id: str, recursive: bool = True):
+        req = pb.PurgeInstancesRequest(instanceId=instance_id, recursive=recursive)
+        self._logger.info(f"Purging instance '{instance_id}'.")
+        await self._stub.PurgeInstances(req)

durabletask/aio/internal/grpc_interceptor.py

@@ -0,0 +1,58 @@
+# Copyright (c) The Dapr Authors.
+# Licensed under the MIT License.
+
+from collections import namedtuple
+
+from grpc import aio as grpc_aio
+
+
+class _ClientCallDetails(
+        namedtuple(
+            '_ClientCallDetails',
+            ['method', 'timeout', 'metadata', 'credentials', 'wait_for_ready', 'compression']),
+        grpc_aio.ClientCallDetails):
+    pass
+
+
+class DefaultClientInterceptorImpl(
+        grpc_aio.UnaryUnaryClientInterceptor, grpc_aio.UnaryStreamClientInterceptor,
+        grpc_aio.StreamUnaryClientInterceptor, grpc_aio.StreamStreamClientInterceptor):
+    """Async gRPC client interceptor to add metadata to all calls."""
+
+    def __init__(self, metadata: list[tuple[str, str]]):
+        super().__init__()
+        self._metadata = metadata
+
+    def _intercept_call(self, client_call_details: _ClientCallDetails) -> grpc_aio.ClientCallDetails:
+        if self._metadata is None:
+            return client_call_details
+
+        if client_call_details.metadata is not None:
+            metadata = list(client_call_details.metadata)
+        else:
+            metadata = []
+
+        metadata.extend(self._metadata)
+        return _ClientCallDetails(
+            client_call_details.method,
+            client_call_details.timeout,
+            metadata,
+            client_call_details.credentials,
+            client_call_details.wait_for_ready,
+            client_call_details.compression)
+
+    async def intercept_unary_unary(self, continuation, client_call_details, request):
+        new_client_call_details = self._intercept_call(client_call_details)
+        return await continuation(new_client_call_details, request)
+
+    async def intercept_unary_stream(self, continuation, client_call_details, request):
+        new_client_call_details = self._intercept_call(client_call_details)
+        return await continuation(new_client_call_details, request)
+
+    async def intercept_stream_unary(self, continuation, client_call_details, request_iterator):
+        new_client_call_details = self._intercept_call(client_call_details)
+        return await continuation(new_client_call_details, request_iterator)
+
+    async def intercept_stream_stream(self, continuation, client_call_details, request_iterator):
+        new_client_call_details = self._intercept_call(client_call_details)
+        return await continuation(new_client_call_details, request_iterator)

durabletask/aio/internal/shared.py

@@ -0,0 +1,49 @@
+# Copyright (c) The Dapr Authors.
+# Licensed under the MIT License.
+
+from typing import Optional, Sequence, Union
+
+import grpc
+from grpc import aio as grpc_aio
+
+from durabletask.internal.shared import (
+    get_default_host_address,
+    SECURE_PROTOCOLS,
+    INSECURE_PROTOCOLS,
+)
+
+
+ClientInterceptor = Union[
+    grpc_aio.UnaryUnaryClientInterceptor,
+    grpc_aio.UnaryStreamClientInterceptor,
+    grpc_aio.StreamUnaryClientInterceptor,
+    grpc_aio.StreamStreamClientInterceptor
+]
+
+
+def get_grpc_aio_channel(
+        host_address: Optional[str],
+        secure_channel: bool = False,
+        interceptors: Optional[Sequence[ClientInterceptor]] = None) -> grpc_aio.Channel:
+
+    if host_address is None:
+        host_address = get_default_host_address()
+
+    for protocol in SECURE_PROTOCOLS:
+        if host_address.lower().startswith(protocol):
+            secure_channel = True
+            host_address = host_address[len(protocol):]
+            break
+
+    for protocol in INSECURE_PROTOCOLS:
+        if host_address.lower().startswith(protocol):
+            secure_channel = False
+            host_address = host_address[len(protocol):]
+            break
+
+    if secure_channel:
+        channel = grpc_aio.secure_channel(host_address, grpc.ssl_channel_credentials(), interceptors=interceptors)
+    else:
+        channel = grpc_aio.insecure_channel(host_address, interceptors=interceptors)
+
+    return channel

durabletask/task.py

@@ -283,13 +283,18 @@ def get_tasks(self) -> list[Task]:
     def on_child_completed(self, task: Task[T]):
         pass
 
+
 class WhenAllTask(CompositeTask[list[T]]):
     """A task that completes when all of its child tasks complete."""
 
     def __init__(self, tasks: list[Task[T]]):
         super().__init__(tasks)
         self._completed_tasks = 0
         self._failed_tasks = 0
+        # If there are no child tasks, this composite should complete immediately
+        if len(self._tasks) == 0:
+            self._result = []  # type: ignore[assignment]
+            self._is_complete = True
 
     @property
     def pending_tasks(self) -> int:
@@ -387,6 +392,10 @@ class WhenAnyTask(CompositeTask[Task]):
 
     def __init__(self, tasks: list[Task]):
         super().__init__(tasks)
+        # If there are no child tasks, complete immediately with an empty result
+        if len(self._tasks) == 0:
+            self._result = []  # type: ignore[assignment]
+            self._is_complete = True
 
     def on_child_completed(self, task: Task):
         # The first task to complete is the result of the WhenAnyTask.

durabletask/worker.py

@@ -880,13 +880,13 @@ class ExecutionResults:
     actions: list[pb.OrchestratorAction]
     encoded_custom_status: Optional[str]
 
-
     def __init__(
             self, actions: list[pb.OrchestratorAction], encoded_custom_status: Optional[str]
     ):
         self.actions = actions
         self.encoded_custom_status = encoded_custom_status
 
+
 class _OrchestrationExecutor:
     _generator: Optional[task.Orchestrator] = None
 

requirements.txt

@@ -1,6 +1,8 @@
 autopep8
 grpcio>=1.60.0 # 1.60.0 is the version introducing protobuf 1.25.X support, newer versions are backwards compatible
 protobuf
+asyncio
 pytest
 pytest-cov
-asyncio
+pytest-asyncio
+flake8

tests/durabletask/test_client.py

@@ -21,6 +21,7 @@ def test_get_grpc_channel_secure():
         get_grpc_channel(HOST_ADDRESS, True, interceptors=INTERCEPTORS)
         mock_channel.assert_called_once_with(HOST_ADDRESS, mock_credentials.return_value)
 
+
 def test_get_grpc_channel_default_host_address():
     with patch('grpc.insecure_channel') as mock_channel:
         get_grpc_channel(None, False, interceptors=INTERCEPTORS)