How to use Flask-Cache with Flask-Restful
As Flask-Cache
implementation doesn't give you access to the underlying cache
object, you'll have to explicitly instantiate a Redis
client and use it's keys
method (list all cache keys).
- The
cache_key
method is used to override the default key generation in yourcache.cached
decorator. - The
clear_cache
method will clear only the portion of the cache corresponding to the current resource.
This is a solution that was tested only for Redis
and the implementation will probably differ a little when using a different cache engine.
from app import cache # The Flask-Cache object
from config import CACHE_REDIS_HOST, CACHE_REDIS_PORT # The Flask-Cache config
from redis import Redis
from flask import request
import urllib
redis_client = Redis(CACHE_REDIS_HOST, CACHE_REDIS_PORT)
def cache_key():
args = request.args
key = request.path + '?' + urllib.urlencode([
(k, v) for k in sorted(args) for v in sorted(args.getlist(k))
])
return key
@api.resource('/whatever')
class Foo(Resource):
@cache.cached(timeout=10, key_prefix=cache_key)
def get(self):
return expensive_db_operation()
def post(self):
update_db_here()
self.clear_cache()
return something_useful()
def clear_cache(self):
# Note: we have to use the Redis client to delete key by prefix,
# so we can't use the 'cache' Flask extension for this one.
key_prefix = request.path
keys = [key for key in redis_client.keys() if key.startswith(key_prefix)]
nkeys = len(keys)
for key in keys:
redis_client.delete(key)
if nkeys > 0:
log.info("Cleared %s cache keys" % nkeys)
log.info(keys)
You can invalidate cache using cache.clear()
method.
For more detials see: https://pythonhosted.org/Flask-Cache/#flask.ext.cache.Cache.clear and Clearing Cache section in https://pythonhosted.org/Flask-Cache/
Yes, you can use like that.
Maybe you will still need to read: flask-cache memoize URL query string parameters as well