Allow negative priorities

This allows both promoting and demoting of jobs

Author: RealOrangeOne

django_dbq/migrations/0003_auto_20180426_1024.py renamed to django_dbq/migrations/0003_auto_20180713_1000.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-# Generated by Django 1.11 on 2018-04-26 10:24
+# Generated by Django 1.11 on 2018-07-13 10:00
 from __future__ import unicode_literals
 
 from django.db import migrations, models
@@ -19,6 +19,6 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='job',
             name='priority',
-            field=models.PositiveSmallIntegerField(db_index=True, default=0),
+            field=models.SmallIntegerField(db_index=True, default=0),
         ),
     ]

django_dbq/models.py

@@ -71,7 +71,7 @@ class Job(models.Model):
     next_task = models.CharField(max_length=100, blank=True)
     workspace = JSONField(null=True)
     queue_name = models.CharField(max_length=20, default='default', db_index=True)
-    priority = models.PositiveSmallIntegerField(default=0, db_index=True)
+    priority = models.SmallIntegerField(default=0, db_index=True)
 
     class Meta:
         ordering = ['-priority', 'created']

django_dbq/tests.py

@@ -113,6 +113,19 @@ def test_gets_jobs_in_priority_order(self):
         self.assertEqual(Job.objects.get_ready_or_none('default'), job_3)
         self.assertFalse(Job.objects.to_process('default').filter(id=job_2.id).exists())
 
+    def test_gets_jobs_in_negative_priority_order(self):
+        job_1 = Job.objects.create(name='testjob')
+        job_2 = Job.objects.create(name='testjob', state=Job.STATES.PROCESSING)
+        job_3 = Job.objects.create(name='testjob', priority=-2)
+        job_4 = Job.objects.create(name='testjob', priority=1)
+        self.assertEqual({
+            job for job in Job.objects.to_process('default')
+        }, {
+            job_4, job_3, job_1
+        })
+        self.assertEqual(Job.objects.get_ready_or_none('default'), job_4)
+        self.assertFalse(Job.objects.to_process('default').filter(id=job_2.id).exists())
+
     def test_gets_jobs_in_priority_and_date_order(self):
         job_1 = Job.objects.create(name='testjob', priority=3)
         job_2 = Job.objects.create(name='testjob', state=Job.STATES.PROCESSING, priority=3)