47 lines
1.4 KiB
Python
47 lines
1.4 KiB
Python
from __future__ import absolute_import
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import datetime
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from django.db import close_connection
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from django.db import (models, transaction, DatabaseError)
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from django.utils.translation import ugettext_lazy as _
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from .managers import LockManager
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#from .settings import DEFAULT_LOCK_TIMEOUT
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DEFAULT_LOCK_TIMEOUT = 60
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class Lock(models.Model):
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creation_datetime = models.DateTimeField(verbose_name=_(u'creation datetime'))
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timeout = models.IntegerField(default=DEFAULT_LOCK_TIMEOUT, verbose_name=_(u'timeout'))
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name = models.CharField(max_length=48, verbose_name=_(u'name'), unique=True)
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objects = LockManager()
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def __unicode__(self):
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return self.name
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def save(self, *args, **kwargs):
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self.creation_datetime = datetime.datetime.now()
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if not self.timeout and not kwargs.get('timeout'):
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self.timeout = DEFAULT_LOCK_TIMEOUT
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super(Lock, self).save(*args, **kwargs)
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@transaction.commit_on_success
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def release(self):
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try:
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close_connection()
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lock = Lock.objects.get(name=self.name, creation_datetime=self.creation_datetime)
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lock.delete()
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except Lock.DoesNotExist:
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# Lock expired and was reassigned
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pass
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except DatabaseError:
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transaction.rollback()
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finally:
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close_connection()
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class Meta:
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verbose_name = _(u'lock')
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verbose_name_plural = _(u'locks')
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