django的cache

使用文件缓存

#settings.py

 

CACHES = {

 

'default': {

 

'BACKEND': 'django.core.cache.backends.filebased.FileBasedCache',

 

'LOCATION': '/var/tmp/django_cache',

 

'TIMEOUT': 3600,

 

'OPTIONS': {

 

'MAX_ENTRIES': 1000

 

}

 

}

 

}

全站缓存

 

#settings.py

 

CACHE_MIDDLEWARE_ALIAS = "default"

 

CACHE_MIDDLEWARE_SECONDS = 300

 

CACHE_MIDDLEWARE_KEY_PREFIX = '站点名'

 

 

MIDDLEWARE_CLASSES = (

 

'django.middleware.cache.UpdateCacheMiddleware',

 

'django.middleware.common.CommonMiddleware',

 

'django.middleware.cache.FetchFromCacheMiddleware',

 

)

用户页面

用户信息页面在登出后不能继续用缓存页面, 而要刷新

使用@vary_on_cookie装饰器

 

from django.views.decorators.vary import vary_on_cookie

 

from django.contrib.auth.decorators import login_required

 

 

@login_required(login_url="/login/")

 

@vary_on_cookie

 

def profile(request):

 

# do something here...

 

return HttpResponse(...)

页面级缓存

 

from django.views.decorators.cache import cache_page,cache_control

 

 

@cache_page(60*5)

 

@cache_control(must_revalidate=True,max_age=60*5)

 

def profile(request):

 

# do something here...

 

return HttpResponse(...)

基于类的视图缓存

 

from django.views.decorators.cache import cache_page,cache_control

 

from app.views import *

 

 

urlpatterns = [

 

url(r'^$',cache_page(60*5)(cache_control(must_revalidate=True,max_age=60*5)(IndexView.as_view()),name="index")),

 

]

刷新缓存

 

from django.core.cache import cache

 

from django.http import HttpRequest

 

from django.utils.cache import get_cache_key

 

 

def expire_page(request,path):

 

# The cache of request url after 'expire/' will be deleted,

 

# so you will get a fresh page !

 

request2 = HttpRequest()

 

request2.META['SERVER_NAME'] = request.META['SERVER_NAME']

 

request2.META['SERVER_PORT'] = request.META['SERVER_PORT']

 

request2.path = request.get_host()+'/'+path

 

print request2.build_absolute_uri()

 

key = get_cache_key(request2)

 

if cache.has_key(key):

 

cache.delete(key)

 

return HttpResponse("OK, the cache is refreshed")

本质上是利用HttpRequest伪造了一个与想要清除缓存的URL地址相同的请求，通过get_cache_key这个函数生成cache_key，然后删除对应的cache，达到刷新页面的效果。函数可以进一步改进至用户前台输入path，然后清除缓存后通过Ajax返回成功信息...