Move code to instructor_task Django app.

lms/djangoapps/instructor_task/models.py

@@ -0,0 +1,63 @@
+"""
+WE'RE USING MIGRATIONS!
+
+If you make changes to this model, be sure to create an appropriate migration
+file and check it in at the same time as your model changes. To do that,
+
+1. Go to the edx-platform dir
+2. ./manage.py schemamigration courseware --auto description_of_your_change
+ 3. Add the migration file created in edx-platform/lms/djangoapps/instructor_task/migrations/
+
+
+ASSUMPTIONS: modules have unique IDs, even across different module_types
+
+"""
+from django.contrib.auth.models import User
+from django.db import models
+
+
+class InstructorTask(models.Model):
+    """
+    Stores information about background tasks that have been submitted to
+    perform work by an instructor (or course staff).
+    Examples include grading and rescoring.
+
+    `task_type` identifies the kind of task being performed, e.g. rescoring.
+    `course_id` uses the course run's unique id to identify the course.
+    `task_input` stores input arguments as JSON-serialized dict, for reporting purposes.
+        Examples include url of problem being rescored, id of student if only one student being rescored.
+    `task_key` stores relevant input arguments encoded into key value for testing to see
+           if the task is already running (together with task_type and course_id).
+
+    `task_id` stores the id used by celery for the background task.
+    `task_state` stores the last known state of the celery task
+    `task_output` stores the output of the celery task.
+        Format is a JSON-serialized dict.  Content varies by task_type and task_state.
+
+    `requester` stores id of user who submitted the task
+    `created` stores date that entry was first created
+    `updated` stores date that entry was last modified
+    """
+    task_type = models.CharField(max_length=50, db_index=True)
+    course_id = models.CharField(max_length=255, db_index=True)
+    task_key = models.CharField(max_length=255, db_index=True)
+    task_input = models.CharField(max_length=255)
+    task_id = models.CharField(max_length=255, db_index=True)  # max_length from celery_taskmeta
+    task_state = models.CharField(max_length=50, null=True, db_index=True)  # max_length from celery_taskmeta
+    task_output = models.CharField(max_length=1024, null=True)
+    requester = models.ForeignKey(User, db_index=True)
+    created = models.DateTimeField(auto_now_add=True, null=True)
+    updated = models.DateTimeField(auto_now=True)
+
+    def __repr__(self):
+        return 'InstructorTask<%r>' % ({
+            'task_type': self.task_type,
+            'course_id': self.course_id,
+            'task_input': self.task_input,
+            'task_id': self.task_id,
+            'task_state': self.task_state,
+            'task_output': self.task_output,
+        },)
+
+    def __unicode__(self):
+        return unicode(repr(self))