resolve #305 abstract models

.gitignore

@@ -30,4 +30,5 @@ cover/
 htmlcov/
 coverage.xml
 .env
-*.ignore
+*.ignore
+.vscode

django_celery_results/admin.py

@@ -10,7 +10,10 @@
     ALLOW_EDITS = False
     pass
 
-from .models import GroupResult, TaskResult
+from .models.helpers import get_group_result_model, get_task_result_model
+
+GroupResult = get_group_result_model()
+TaskResult = get_task_result_model()
 
 
 class TaskResultAdmin(admin.ModelAdmin):

django_celery_results/backends/database.py

@@ -12,9 +12,12 @@
 from django.db.utils import InterfaceError
 from kombu.exceptions import DecodeError
 
-from ..models import ChordCounter
-from ..models import GroupResult as GroupResultModel
-from ..models import TaskResult
+from ..models.helpers import (
+    get_chord_counter_model,
+    get_group_result_model,
+    get_task_result_model,
+)
+from ..settings import get_task_props_extension
 
 EXCEPTIONS_TO_CATCH = (InterfaceError,)
 
@@ -30,8 +33,9 @@
 class DatabaseBackend(BaseDictBackend):
     """The Django database backend, using models to store task state."""
 
-    TaskModel = TaskResult
-    GroupModel = GroupResultModel
+    TaskModel = get_task_result_model()
+    GroupModel = get_group_result_model()
+    ChordCounterModel = get_chord_counter_model()
     subpolling_interval = 0.5
 
     def exception_safe_to_retry(self, exc):
@@ -80,6 +84,14 @@ def _get_extended_properties(self, request, traceback):
                 # task protocol 1
                 task_kwargs = getattr(request, 'kwargs', None)
 
+            # TODO: We assume that task protocol 1 could be always in use. :/
+            extra_fields = get_task_props_extension(
+                request,
+                getattr(request, 'kwargs', None)
+            )
+            if extra_fields:
+                extended_props.update({"extra_fields": extra_fields})
+
             # Encode input arguments
             if task_args is not None:
                 _, _, task_args = self.encode_content(task_args)
@@ -141,9 +153,8 @@ def _store_result(
             'using': using,
         }
 
-        task_props.update(
-            self._get_extended_properties(request, traceback)
-        )
+        task_props.update(self._get_extended_properties(request, traceback))
+        task_props.update(get_task_props_extension(request, dict(task_props)))
 
         if status == states.STARTED:
             task_props['date_started'] = Now()
@@ -242,7 +253,7 @@ def apply_chord(self, header_result_args, body, **kwargs):
         results = [r.as_tuple() for r in header_result]
         chord_size = body.get("chord_size", None) or len(results)
         data = json.dumps(results)
-        ChordCounter.objects.create(
+        self.ChordCounterModel.objects.create(
             group_id=header_result.id, sub_tasks=data, count=chord_size
         )
 
@@ -252,17 +263,19 @@ def on_chord_part_return(self, request, state, result, **kwargs):
         if not gid or not tid:
             return
         call_callback = False
-        with transaction.atomic(using=router.db_for_write(ChordCounter)):
+        with transaction.atomic(
+            using=router.db_for_write(self.ChordCounterModel)
+        ):
             # We need to know if `count` hits 0.
             # wrap the update in a transaction
             # with a `select_for_update` lock to prevent race conditions.
             # SELECT FOR UPDATE is not supported on all databases
             try:
                 chord_counter = (
-                    ChordCounter.objects.select_for_update()
+                    self.ChordCounterModel.objects.select_for_update()
                     .get(group_id=gid)
                 )
-            except ChordCounter.DoesNotExist:
+            except self.ChordCounterModel.DoesNotExist:
                 logger.warning("Can't find ChordCounter for Group %s", gid)
                 return
             chord_counter.count -= 1

django_celery_results/managers.py

@@ -125,7 +125,7 @@ def store_result(self, content_type, content_encoding,
                      traceback=None, meta=None,
                      periodic_task_name=None,
                      task_name=None, task_args=None, task_kwargs=None,
-                     worker=None, using=None, **kwargs):
+                     worker=None, using=None, extra_fields=None, **kwargs):
         """Store the result and status of a task.
 
         Arguments:
@@ -146,6 +146,7 @@ def store_result(self, content_type, content_encoding,
                 exception (only passed if the task failed).
             meta (str): Serialized result meta data (this contains e.g.
                 children).
+            extra_fields (dict, optional): Extra (model) fields to store.
 
         Keyword Arguments:
             exception_retry_count (int): How many times to retry by
@@ -165,8 +166,12 @@ def store_result(self, content_type, content_encoding,
             'task_name': task_name,
             'task_args': task_args,
             'task_kwargs': task_kwargs,
-            'worker': worker
+            'worker': worker,
         }
+
+        if extra_fields is not None:
+            fields.update(extra_fields)
+
         if 'date_started' in kwargs:
             fields['date_started'] = kwargs['date_started']
 

django_celery_results/models/__init__.py

@@ -0,0 +1,3 @@
+from .generic import ChordCounter, GroupResult, TaskResult
+
+__all__ = ["ChordCounter", "GroupResult", "TaskResult"]

django_celery_results/models.py → django_celery_results/models/abstract.py

@@ -1,4 +1,4 @@
-"""Database models."""
+"""Abstract models."""
 
 import json
 
@@ -9,14 +9,14 @@
 from django.db import models
 from django.utils.translation import gettext_lazy as _
 
-from . import managers
+from .. import managers
 
 ALL_STATES = sorted(states.ALL_STATES)
 TASK_STATE_CHOICES = sorted(zip(ALL_STATES, ALL_STATES))
 
 
-class TaskResult(models.Model):
-    """Task result/status."""
+class AbstractTaskResult(models.Model):
+    """Abstract Task result/status."""
 
     task_id = models.CharField(
         max_length=getattr(
@@ -97,8 +97,8 @@ class TaskResult(models.Model):
     class Meta:
         """Table information."""
 
+        abstract = True
         ordering = ['-date_done']
-
         verbose_name = _('task result')
         verbose_name_plural = _('task results')
 
@@ -136,14 +136,15 @@ def __str__(self):
         return '<Task: {0.task_id} ({0.status})>'.format(self)
 
 
-class ChordCounter(models.Model):
-    """Chord synchronisation."""
+class AbstractChordCounter(models.Model):
+    """Abstract Chord synchronisation."""
 
     group_id = models.CharField(
         max_length=getattr(
             settings,
             "DJANGO_CELERY_RESULTS_TASK_ID_MAX_LENGTH",
-            255),
+            255
+        ),
         unique=True,
         verbose_name=_("Group ID"),
         help_text=_("Celery ID for the Chord header group"),
@@ -161,12 +162,17 @@ class ChordCounter(models.Model):
         )
     )
 
+    class Meta:
+        """Table information."""
+
+        abstract = True
+
     def group_result(self, app=None):
-        """Return the :class:`celery.result.GroupResult` of self.
+        """Return the GroupResult of self.
 
         Arguments:
-            app (celery.app.base.Celery): app instance to create the
-               :class:`celery.result.GroupResult` with.
+        ---------
+            app (Celery): app instance to create the GroupResult with.
 
         """
         return CeleryGroupResult(
@@ -177,8 +183,8 @@ def group_result(self, app=None):
         )
 
 
-class GroupResult(models.Model):
-    """Task Group result/status."""
+class AbstractGroupResult(models.Model):
+    """Abstract Task Group result/status."""
 
     group_id = models.CharField(
         max_length=getattr(
@@ -231,10 +237,10 @@ def __str__(self):
     class Meta:
         """Table information."""
 
-        ordering = ['-date_done']
-
+        abstract = True
         verbose_name = _('group result')
         verbose_name_plural = _('group results')
+        ordering = ['-date_done']
 
         # Explicit names to solve https://code.djangoproject.com/ticket/33483
         indexes = [

django_celery_results/models/generic.py

@@ -0,0 +1,40 @@
+"""Database models."""
+
+from django_celery_results.models.abstract import (
+    AbstractChordCounter,
+    AbstractGroupResult,
+    AbstractTaskResult,
+)
+
+
+class TaskResult(AbstractTaskResult):
+    """Task result/status."""
+
+    class Meta(AbstractTaskResult.Meta):
+        """Table information."""
+
+        abstract = False
+        app_label = "django_celery_results"
+        swappable = "CELERY_RESULTS_TASKRESULT_MODEL"
+
+
+class ChordCounter(AbstractChordCounter):
+    """Chord synchronisation."""
+
+    class Meta(AbstractChordCounter.Meta):
+        """Table information."""
+
+        abstract = False
+        app_label = "django_celery_results"
+        swappable = "CELERY_RESULTS_CHORDCOUNTER_MODEL"
+
+
+class GroupResult(AbstractGroupResult):
+    """Task Group result/status."""
+
+    class Meta(AbstractGroupResult.Meta):
+        """Table information."""
+
+        abstract = False
+        app_label = "django_celery_results"
+        swappable = "CELERY_RESULTS_GROUPRESULT_MODEL"

django_celery_results/models/helpers.py

@@ -0,0 +1,72 @@
+from django.apps import apps
+from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
+
+from .generic import ChordCounter, GroupResult, TaskResult
+
+
+def get_task_result_model():
+    """Return the TaskResult model that is active in this project."""
+    if not hasattr(settings, 'CELERY_RESULTS_TASKRESULT_MODEL'):
+        return TaskResult
+
+    try:
+        return apps.get_model(
+            settings.CELERY_RESULTS_TASKRESULT_MODEL
+        )
+    except ValueError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_TASKRESULT_MODEL must be of the form "
+            "'app_label.model_name'"
+        )
+    except LookupError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_TASKRESULT_MODEL refers to model "
+            f"'{settings.CELERY_RESULTS_TASKRESULT_MODEL}' that has not "
+            "been installed"
+        )
+
+
+def get_chord_counter_model():
+    """Return the ChordCounter model that is active in this project."""
+
+    if not hasattr(settings, 'CELERY_RESULTS_CHORDCOUNTER_MODEL'):
+        return ChordCounter
+
+    try:
+        return apps.get_model(
+            settings.CELERY_RESULTS_CHORDCOUNTER_MODEL
+        )
+    except ValueError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_CHORDCOUNTER_MODEL must be of the form "
+            "'app_label.model_name'"
+        )
+    except LookupError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_CHORDCOUNTER_MODEL refers to model "
+            f"'{settings.CELERY_RESULTS_CHORDCOUNTER_MODEL}' that has not "
+            "been installed"
+        )
+
+
+def get_group_result_model():
+    """Return the GroupResult model that is active in this project."""
+    if not hasattr(settings, 'CELERY_RESULTS_GROUPRESULT_MODEL'):
+        return GroupResult
+
+    try:
+        return apps.get_model(
+            settings.CELERY_RESULTS_GROUPRESULT_MODEL
+        )
+    except ValueError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_GROUPRESULT_MODEL must be of the form "
+            "'app_label.model_name'"
+        )
+    except LookupError:
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_GROUPRESULT_MODEL refers to model "
+            f"'{settings.CELERY_RESULTS_GROUPRESULT_MODEL}' that has not "
+            "been installed"
+        )

django_celery_results/settings.py

@@ -0,0 +1,35 @@
+from collections.abc import Mapping
+
+from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
+
+
+def get_callback_function(settings_name, default=None):
+    """Return the callback function for the given settings name."""
+    callback = getattr(settings, settings_name, None)
+    if not callback:
+        return default
+
+    if not callable(callback):
+        raise ImproperlyConfigured(f"{settings_name} must be callable.")
+
+    return callback
+
+
+extend_task_props_callback = get_callback_function(
+    "CELERY_RESULTS_EXTEND_TASK_PROPS_CALLBACK"
+)
+
+
+def get_task_props_extension(request, task_props):
+    """Extend the task properties with custom props to fill custom models."""
+    if not extend_task_props_callback:
+        return {}
+
+    task_props_extension = extend_task_props_callback(request, task_props) or {}  # noqa E501
+    if not isinstance(task_props_extension, Mapping):
+        raise ImproperlyConfigured(
+            "CELERY_RESULTS_EXTEND_TASK_PROPS_CALLBACK must return a Mapping."
+        )
+
+    return task_props_extension