40 lines
1.2 KiB
Python
40 lines
1.2 KiB
Python
from __future__ import unicode_literals
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from django.db import models
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from django.utils.encoding import python_2_unicode_compatible
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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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@python_2_unicode_compatible
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class Lock(models.Model):
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creation_datetime = models.DateTimeField(auto_now_add=True, verbose_name=_('Creation datetime'))
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timeout = models.IntegerField(default=DEFAULT_LOCK_TIMEOUT, verbose_name=_('Timeout'))
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name = models.CharField(max_length=64, unique=True, verbose_name=_('Name'))
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objects = LockManager()
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def __str__(self):
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return self.name
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def save(self, *args, **kwargs):
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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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def release(self):
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try:
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lock = Lock.objects.get(name=self.name, creation_datetime=self.creation_datetime)
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except Lock.DoesNotExist:
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# Our lock has expired and was reassigned
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pass
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else:
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lock.delete()
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class Meta:
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verbose_name = _('Lock')
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verbose_name_plural = _('Locks')
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