+from os.path import join, abspath, exists
+from django.db import models
+from waiter.settings import WAITER_ROOT, WAITER_URL
+from django.core.urlresolvers import reverse
+
+class WaitedFile(models.Model):
+ path = models.CharField(max_length=255, unique=True, db_index=True)
+ task = models.CharField(max_length=64, null=True, editable=False)
+ description = models.CharField(max_length=255, null=True, blank=True)
+
+ @staticmethod
+ def abspath(path):
+ abs_path = abspath(join(WAITER_ROOT, path))
+ if not abs_path.startswith(WAITER_ROOT):
+ raise ValueError('Path not inside WAITER_ROOT.')
+ return abs_path
+
+ @classmethod
+ def exists(cls, path):
+ """Returns opened file or None.
+
+ `path` is relative to WAITER_ROOT.
+ Won't open a path leading outside of WAITER_ROOT.
+ """
+ abs_path = cls.abspath(path)
+ # Pre-fetch objects to avoid minor race condition
+ relevant = [o.id for o in cls.objects.filter(path=path)]
+ print abs_path
+ if exists(abs_path):
+ cls.objects.filter(id__in=relevant).delete()
+ return True
+ else:
+ return False
+
+ @classmethod
+ def order(cls, path, task_creator, description=None):
+ """
+ Returns an URL for the user to follow.
+ If the file is ready, returns download URL.
+ If not, starts preparing it and returns waiting URL.
+ """
+ already = cls.exists(path)
+ if not already:
+ waited, created = cls.objects.get_or_create(path=path)
+ if created:
+ # TODO: makedirs
+ waited.task = task_creator(cls.abspath(path))
+ print waited.task
+ waited.description = description
+ waited.save()
+ # TODO: it the task exists, if stale delete, send some mail and restart
+ return reverse("waiter", args=[path])
+ return join(WAITER_URL, path)
fnp / wolnelektury.git / commitdiff