Leverage `first_task` in `get_ready_engine_steps` (#1858)

* WIP

* Getting pyl to pass

* WIP

spiffworkflow-backend/src/spiffworkflow_backend/services/process_instance_processor.py

@@ -1569,6 +1569,7 @@ class ProcessInstanceProcessor:
             exit_at,
             save,
             should_schedule_waiting_timer_events=should_schedule_waiting_timer_events,
+            # profile=True,
         )
         self.task_model_mapping, self.bpmn_subprocess_mapping = task_model_delegate.get_guid_to_db_object_mappings()
         self.check_all_tasks()

spiffworkflow-backend/src/spiffworkflow_backend/services/workflow_execution_service.py

@@ -21,7 +21,8 @@ from SpiffWorkflow.bpmn.specs.mixins.events.event_types import CatchingEvent  #
 from SpiffWorkflow.bpmn.workflow import BpmnWorkflow  # type: ignore
 from SpiffWorkflow.exceptions import SpiffWorkflowException  # type: ignore
 from SpiffWorkflow.task import Task as SpiffTask  # type: ignore
-from SpiffWorkflow.util.task import TaskState  # type: ignore
+from SpiffWorkflow.util.task import TaskFilter  # type: ignore
+from SpiffWorkflow.util.task import TaskState
 
 from spiffworkflow_backend.background_processing.celery_tasks.process_instance_task_producer import (
     queue_future_task_if_appropriate,
@@ -95,6 +96,10 @@ class EngineStepDelegate:
     def on_exception(self, bpmn_process_instance: BpmnWorkflow) -> None:
         pass
 
+    @abstractmethod
+    def last_completed_spiff_task(self) -> SpiffTask | None:
+        pass
+
 
 class ExecutionStrategy:
     """Interface of sorts for a concrete execution strategy."""
@@ -195,7 +200,23 @@ class ExecutionStrategy:
         self.delegate.add_object_to_db_session(bpmn_process_instance)
 
     def get_ready_engine_steps(self, bpmn_process_instance: BpmnWorkflow) -> list[SpiffTask]:
-        return [t for t in bpmn_process_instance.get_tasks(state=TaskState.READY) if not t.task_spec.manual]
+        task_filter = TaskFilter(state=TaskState.READY, manual=False)
+
+        steps = list(
+            bpmn_process_instance.get_tasks(
+                first_task=self.delegate.last_completed_spiff_task(),
+                task_filter=task_filter,
+            )
+        )
+
+        if not steps:
+            steps = list(
+                bpmn_process_instance.get_tasks(
+                    task_filter=task_filter,
+                )
+            )
+
+        return steps
 
     def _run_engine_steps_with_threads(
         self, engine_steps: list[SpiffTask], process_instance: ProcessInstanceModel, user: UserModel | None
@@ -261,7 +282,7 @@ class TaskModelSavingDelegate(EngineStepDelegate):
 
         self.current_task_start_in_seconds: float | None = None
 
-        self.last_completed_spiff_task: SpiffTask | None = None
+        self._last_completed_spiff_task: SpiffTask | None = None
         self.spiff_tasks_to_process: set[UUID] = set()
         self.spiff_task_timestamps: dict[UUID, StartAndEndTimes] = {}
 
@@ -293,7 +314,6 @@ class TaskModelSavingDelegate(EngineStepDelegate):
             task_model.start_in_seconds = self.current_task_start_in_seconds
             task_model.end_in_seconds = time.time()
 
-            self.last_completed_spiff_task = spiff_task
         if (
             spiff_task.task_spec.__class__.__name__ in ["StartEvent", "EndEvent", "IntermediateThrowEvent"]
             and spiff_task.task_spec.bpmn_name is not None
@@ -306,6 +326,7 @@ class TaskModelSavingDelegate(EngineStepDelegate):
             elif spiff_task.task_spec.__class__.__name__ == "StartEvent":
                 self.process_instance.last_milestone_bpmn_name = "Started"
         self.process_instance.task_updated_at_in_seconds = round(time.time())
+        self._last_completed_spiff_task = spiff_task
         if self.secondary_engine_step_delegate:
             self.secondary_engine_step_delegate.did_complete_task(spiff_task)
 
@@ -347,6 +368,9 @@ class TaskModelSavingDelegate(EngineStepDelegate):
         """No reason to save task model stuff if the process instance isn't persistent."""
         return self.process_instance.persistence_level != "none"
 
+    def last_completed_spiff_task(self) -> SpiffTask | None:
+        return self._last_completed_spiff_task
+
 
 class GreedyExecutionStrategy(ExecutionStrategy):
     """
@@ -471,6 +495,25 @@ class WorkflowExecutionService:
         exit_at: None = None,
         save: bool = False,
         should_schedule_waiting_timer_events: bool = True,
+        profile: bool = False,
+    ) -> TaskRunnability:
+        if profile:
+            import cProfile
+            from pstats import SortKey
+
+            task_runnability = TaskRunnability.unknown_if_ready_tasks
+            with cProfile.Profile() as pr:
+                task_runnability = self._run_and_save(exit_at, save, should_schedule_waiting_timer_events)
+            pr.print_stats(sort=SortKey.CUMULATIVE)
+            return task_runnability
+
+        return self._run_and_save(exit_at, save, should_schedule_waiting_timer_events)
+
+    def _run_and_save(
+        self,
+        exit_at: None = None,
+        save: bool = False,
+        should_schedule_waiting_timer_events: bool = True,
     ) -> TaskRunnability:
         if self.process_instance_model.persistence_level != "none":
             with safe_assertion(ProcessInstanceLockService.has_lock(self.process_instance_model.id)) as tripped:
@@ -610,24 +653,3 @@ class WorkflowExecutionService:
                 bpmn_process_correlations = self.bpmn_process_instance.correlations
                 bpmn_process.properties_json["correlations"] = bpmn_process_correlations
                 db.session.add(bpmn_process)
-
-
-class ProfiledWorkflowExecutionService(WorkflowExecutionService):
-    """A profiled version of the workflow execution service."""
-
-    def run_and_save(
-        self,
-        exit_at: None = None,
-        save: bool = False,
-        should_schedule_waiting_timer_events: bool = True,
-    ) -> TaskRunnability:
-        import cProfile
-        from pstats import SortKey
-
-        task_runnability = TaskRunnability.unknown_if_ready_tasks
-        with cProfile.Profile() as pr:
-            task_runnability = super().run_and_save(
-                exit_at=exit_at, save=save, should_schedule_waiting_timer_events=should_schedule_waiting_timer_events
-            )
-        pr.print_stats(sort=SortKey.CUMULATIVE)
-        return task_runnability