Create and use a decorator for background functions

app/jobs/background_functions.py

@@ -1,9 +0,0 @@
-from ..models import Job
-
-
-def delete_job_(app, job_id):
-    with app.app_context():
-        job = Job.query.get(job_id)
-        if job is None:
-            raise Exception('Job {} not found!'.format(job_id))
-        job.delete()

app/jobs/tasks.py

@@ -0,0 +1,28 @@
+from time import sleep
+from .. import db
+from ..decorators import background
+from ..models import Job
+import os
+import shutil
+
+
+@background
+def delete_job(app, job_id):
+    with app.app_context():
+        job = Job.query.get(job_id)
+        if job is None:
+            return
+        if job.status not in ['complete', 'failed']:
+            job.status = 'canceling'
+            db.session.commit()
+            while job.status != 'canceled':
+                # In case the daemon handled a job in any way
+                if job.status != 'canceling':
+                    job.status = 'canceling'
+                    db.session.commit()
+                sleep(1)
+                db.session.refresh(job)
+        path = os.path.join(app.config['NOPAQUE_STORAGE'], str(job.user_id),
+                            'jobs', str(job.id))
+        shutil.rmtree(path, ignore_errors=True)
+        job.delete()

app/jobs/views.py

@@ -1,9 +1,8 @@
 from flask import (abort, current_app, flash, redirect, render_template,
                    send_from_directory, url_for)
 from flask_login import current_user, login_required
-from threading import Thread
 from . import jobs
-from .background_functions import delete_job_
+from . import tasks
 from ..models import Job, JobInput, JobResult
 import os
 
@@ -23,9 +22,7 @@ def delete_job(job_id):
     job = Job.query.get_or_404(job_id)
     if not (job.creator == current_user or current_user.is_administrator()):
         abort(403)
-    thread = Thread(target=delete_job_,
-                    args=(current_app._get_current_object(), job_id))
-    thread.start()
+    tasks.delete_job(job_id)
     flash('Job has been deleted!')
     return redirect(url_for('main.dashboard'))