基於賈斯汀莉莉的回答,我創建了一個自定義管理器,它將post_save信號綁定到類的每個孩子,無論是否抽象。
這是一次性的,測試不當的代碼,所以要小心!儘管如此,它仍然有效。
在此示例中,我們允許抽象模型將CachedModelManager定義爲管理器,然後將基本高速緩存功能擴展到模型及其子級。它允許您定義每次保存時應刪除的易失性密鑰列表(因此是post_save信號),並添加一些輔助函數來生成緩存密鑰,以及檢索,設置和刪除密鑰。
這當然假設您有一個緩存後端設置並正常工作。
# helperapp\models.py
# -*- coding: UTF-8
from django.db import models
from django.core.cache import cache
class CachedModelManager(models.Manager):
def contribute_to_class(self, model, name):
super(CachedModelManager, self).contribute_to_class(model, name)
setattr(model, 'volatile_cache_keys',
getattr(model, 'volatile_cache_keys', []))
setattr(model, 'cache_key', getattr(model, 'cache_key', cache_key))
setattr(model, 'get_cache', getattr(model, 'get_cache', get_cache))
setattr(model, 'set_cache', getattr(model, 'set_cache', set_cache))
setattr(model, 'del_cache', getattr(model, 'del_cache', del_cache))
self._bind_flush_signal(model)
def _bind_flush_signal(self, model):
models.signals.post_save.connect(flush_volatile_keys, model)
def flush_volatile_keys(sender, **kwargs):
instance = kwargs.pop('instance', False)
for key in instance.volatile_cache_keys:
instance.del_cache(key)
def cache_key(instance, key):
if not instance.pk:
name = "%s.%s" % (instance._meta.app_label, instance._meta.module_name)
raise models.ObjectDoesNotExist("Can't generate a cache key for " +
"this instance of '%s' " % name +
"before defining a primary key.")
else:
return "%s.%s.%s.%s" % (instance._meta.app_label,
instance._meta.module_name,
instance.pk, key)
def get_cache(instance, key):
result = cache.get(instance.cache_key(key))
return result
def set_cache(instance, key, value, timeout=60*60*24*3):
result = cache.set(instance.cache_key(key), value, timeout)
return result
def del_cache(instance, key):
result = cache.delete(instance.cache_key(key))
return result
# myapp\models.py
from django.contrib.auth.models import User
from django.db import models
from helperapp.models import CachedModelManager
class Abstract(models.Model):
creator = models.ForeignKey(User)
cache = CachedModelManager()
class Meta:
abstract = True
class Community(Abstract):
members = models.ManyToManyField(User)
volatile_cache_keys = ['members_list',]
@property
def members_list(self):
result = self.get_cache('members_list')
if not result:
result = self.members.all()
self.set_cache('members_list', result)
return result
修補程序歡迎!
我明白這個背後的想法,但是你可以用一個例子來闡述一下嗎?這將有助於保持我目前項目的乾爽。 – 2012-05-15 14:47:39
編輯:我試着在你自己的答案中提出你的建議..它適用於我,但我不是100%確定! – 2012-05-15 16:29:33
沒有官方的文檔'contribute_to_class' ... – Raffi 2017-11-13 08:48:30