Files
mayan-edms/apps/queue_manager/models.py
2012-07-29 05:31:45 -04:00

96 lines
2.9 KiB
Python
Executable File

from __future__ import absolute_import
from datetime import datetime
from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.simplejson import loads, dumps
from django.db import IntegrityError
from .exceptions import QueuePushError
queue_labels = {}
class QueueManager(models.Manager):
def get_or_create(self, *args, **kwargs):
queue_labels[kwargs.get('name')] = kwargs.get('defaults', {}).get('label')
return super(QueueManager, self).get_or_create(*args, **kwargs)
class Queue(models.Model):
# Internal name
name = models.CharField(max_length=32, verbose_name=_(u'name'), unique=True)
unique_names = models.BooleanField(verbose_name=_(u'unique names'), default=False)
objects = QueueManager()
def __unicode__(self):
return unicode(self.label) or self.name
@property
def label(self):
return queue_labels.get(self.name)
def push(self, data, name=None): # TODO: add replace flag
if not name:
name = u''
queue_item = QueueItem(queue=self, name=name, data=dumps(data))
queue_item.save()
return queue_item
def pull(self):
queue_item_qs = QueueItem.objects.filter(queue=self).order_by('-creation_datetime')
if queue_item_qs:
queue_item = queue_item_qs[0]
queue_item.delete()
return loads(queue_item.data)
@property
def items(self):
return self.queueitem_set
def empty(self):
self.items.all().delete()
def save(self, *args, **kwargs):
label = getattr(self, 'label', None)
if label:
queue_labels[self.name] = label
return super(Queue, self).save(*args, **kwargs)
# TODO: custom runtime methods
class Meta:
verbose_name = _(u'queue')
verbose_name_plural = _(u'queues')
class QueueItem(models.Model):
queue = models.ForeignKey(Queue, verbose_name=_(u'queue'))
creation_datetime = models.DateTimeField(verbose_name=_(u'creation datetime'), editable=False)
unique_name = models.CharField(blank=True, max_length=32, verbose_name=_(u'name'), unique=True, editable=False)
name = models.CharField(blank=True, max_length=32, verbose_name=_(u'name'))
data = models.TextField(verbose_name=_(u'data'))
def __unicode__(self):
return self.name
def save(self, *args, **kwargs):
self.creation_datetime = datetime.now()
if self.queue.unique_names:
self.unique_name = self.name
else:
self.unique_name = unicode(self.creation_datetime)
try:
super(QueueItem, self).save(*args, **kwargs)
except IntegrityError:
# TODO: Maybe replace instead or rasining exception w/ replace flag
raise QueuePushError
class Meta:
verbose_name = _(u'queue item')
verbose_name_plural = _(u'queue items')