Add queue manager app

apps/queue_manager/__init__.py

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+from queue_manager.models import Queue as QueueModel, QueuePushError
+
+class Queue(object):
+    @classmethod
+    def __new__(cls, name, queue_name, label=None, unique_names=False):
+        name = queue_name
+        if not label:
+            label=u''
+        queue, created = QueueModel.objects.get_or_create(
+            name=name,
+            defaults={
+                'label': label,
+                'unique_names': unique_names
+            }
+        )
+        if not created:
+            queue.label = label
+            queue.unique_names = unique_names
+            queue.save()
+        return queue

apps/queue_manager/admin.py

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+from django.contrib import admin
+
+from django.utils.translation import ugettext_lazy as _
+
+from queue_manager.models import Queue, QueueItem
+
+
+class QueueItemInline(admin.StackedInline):
+    model = QueueItem
+
+
+class QueueAdmin(admin.ModelAdmin):
+    model = Queue
+    list_display = ('name', 'label', 'total_items')
+    inlines = [QueueItemInline]
+
+    def total_items(self, obj):
+        return obj.items.all().count()
+    total_items.short_description = _(u'total items')
+
+
+admin.site.register(Queue, QueueAdmin)

apps/queue_manager/exceptions.py

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+class QueueException(Exception):
+    pass
+
+    
+class QueuePushError(QueueException):
+    pass

apps/queue_manager/migrations/0001_initial.py

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+# -*- coding: utf-8 -*-
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'Queue'
+        db.create_table('queue_manager_queue', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('name', self.gf('django.db.models.fields.CharField')(unique=True, max_length=32)),
+            ('unique_names', self.gf('django.db.models.fields.BooleanField')(default=False)),
+        ))
+        db.send_create_signal('queue_manager', ['Queue'])
+
+        # Adding model 'QueueItem'
+        db.create_table('queue_manager_queueitem', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('queue', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['queue_manager.Queue'])),
+            ('creation_datetime', self.gf('django.db.models.fields.DateTimeField')()),
+            ('unique_name', self.gf('django.db.models.fields.CharField')(unique=True, max_length=32, blank=True)),
+            ('name', self.gf('django.db.models.fields.CharField')(max_length=32, blank=True)),
+            ('data', self.gf('django.db.models.fields.TextField')()),
+        ))
+        db.send_create_signal('queue_manager', ['QueueItem'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'Queue'
+        db.delete_table('queue_manager_queue')
+
+        # Deleting model 'QueueItem'
+        db.delete_table('queue_manager_queueitem')
+
+
+    models = {
+        'queue_manager.queue': {
+            'Meta': {'object_name': 'Queue'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32'}),
+            'unique_names': ('django.db.models.fields.BooleanField', [], {'default': 'False'})
+        },
+        'queue_manager.queueitem': {
+            'Meta': {'object_name': 'QueueItem'},
+            'creation_datetime': ('django.db.models.fields.DateTimeField', [], {}),
+            'data': ('django.db.models.fields.TextField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '32', 'blank': 'True'}),
+            'queue': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['queue_manager.Queue']"}),
+            'unique_name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32', 'blank': 'True'})
+        }
+    }
+
+    complete_apps = ['queue_manager']

apps/queue_manager/models.py

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+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')
+    

apps/queue_manager/views.py

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+# Create your views here.