Run build completion in background (#6619)

- Long running tasks pushed to background worker
- Closes https://github.com/inventree/InvenTree/issues/5157

InvenTree/build/models.py

@@ -518,9 +518,25 @@ class Build(InvenTree.models.InvenTreeBarcodeMixin, InvenTree.models.InvenTreeNo
 
         return True
 
+    @transaction.atomic
+    def complete_allocations(self, user):
+        """Complete all stock allocations for this build order.
+
+        - This function is called when a build order is completed
+        """
+        # Remove untracked allocated stock
+        self.subtract_allocated_stock(user)
+
+        # Ensure that there are no longer any BuildItem objects
+        # which point to this Build Order
+        self.allocated_stock.delete()
+
     @transaction.atomic
     def complete_build(self, user):
         """Mark this build as complete."""
+
+        import build.tasks
+
         if self.incomplete_count > 0:
             return
 
@@ -529,12 +545,12 @@ class Build(InvenTree.models.InvenTreeBarcodeMixin, InvenTree.models.InvenTreeNo
         self.status = BuildStatus.COMPLETE.value
         self.save()
 
-        # Remove untracked allocated stock
-        self.subtract_allocated_stock(user)
-
-        # Ensure that there are no longer any BuildItem objects
-        # which point to this Build Order
-        self.allocated_stock.delete()
+        # Offload task to complete build allocations
+        InvenTree.tasks.offload_task(
+            build.tasks.complete_build_allocations,
+            self.pk,
+            user.pk if user else None
+        )
 
         # Register an event
         trigger_event('build.completed', id=self.pk)

InvenTree/build/tasks.py

@@ -4,6 +4,7 @@ from datetime import datetime, timedelta
 from decimal import Decimal
 import logging
 
+from django.contrib.auth.models import User
 from django.utils.translation import gettext_lazy as _
 from django.template.loader import render_to_string
 
@@ -24,6 +25,27 @@ import part.models as part_models
 logger = logging.getLogger('inventree')
 
 
+def complete_build_allocations(build_id: int, user_id: int):
+    """Complete build allocations for a specified BuildOrder."""
+
+    build_order = build.models.Build.objects.filter(pk=build_id).first()
+
+    if user_id:
+        try:
+            user = User.objects.get(pk=user_id)
+        except User.DoesNotExist:
+            logger.warning("Could not complete build allocations for BuildOrder <%s> - User does not exist", build_id)
+            return
+    else:
+        user = None
+
+    if not build_order:
+        logger.warning("Could not complete build allocations for BuildOrder <%s> - BuildOrder does not exist", build_id)
+        return
+
+    build_order.complete_allocations(user)
+
+
 def update_build_order_lines(bom_item_pk: int):
     """Update all BuildOrderLineItem objects which reference a particular BomItem.