Caching

New in version 1.3.

There is a Superdesk wrapper for Hermes cache.

Basic usage is:

from superdesk.cache import cache

@cache(ttl=30)
def some_func(foo):
    return foo * 5


class Service():

    @cache(ttl=50)
    def foo(self):
        return

Cache providers

Redis

This one is enabled by default, using REDIS_URL for config.

Memcached

In order to use memcached:

• install python3-memcached library

• set SUPERDESK_CACHE_URL env var to your memcached instance, or set it via CACHE_URL in settings.

App Context

It requires flask.app for the config, you can still annotate methods/functions before the app is created, but you can not call these methods before there is an app context in place.

Serialization

Cache handles superdesk data encoding/decoding so you will get datetime and ObjectId instances. However, it doesn’t handle yet more complex types - like Cursor objects returned after mongo/elastic queries:

@cache(ttl=50)
def return_from_db():
    return get_resource_service('foo').get()

Will raise an error. What you can do instead:

@cache(ttl=50)
def return_from_db():
    return [doc for doc in get_resource_service('foo').get()]