Configuration

Cache aliases

The caches module allows to setup cache configurations and then use them either using an alias or retrieving the config explicitly. To set the config, call caches.set_config:

caches.set_config(config)

Set (override) the default config for cache aliases from a dict-like structure. The structure is the following:

{
    'default': {
        'cache': "aiocache.SimpleMemoryCache",
        'serializer': {
            'class': "aiocache.serializers.StringSerializer"
        }
    },
    'redis_alt': {
        'cache': "aiocache.RedisCache",
        'endpoint': "127.0.0.10",
        'port': 6378,
        'serializer': {
            'class': "aiocache.serializers.PickleSerializer"
        },
        'plugins': [
            {'class': "aiocache.plugins.HitMissRatioPlugin"},
            {'class': "aiocache.plugins.TimingPlugin"}
        ]
    }
}

‘default’ key must always exist when passing a new config. Default configuration is:

{
    'default': {
        'cache': "aiocache.SimpleMemoryCache",
        'serializer': {
            'class': "aiocache.serializers.StringSerializer"
        }
    }
}

You can set your own classes there. The class params accept both str and class types.

All keys in the config are optional, if they are not passed the defaults for the specified class will be used.

To retrieve a copy of the current config, you can use caches.get_config or caches.get_alias_config for an alias config.

Next snippet shows an example usage:

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import asyncio

from aiocache import caches, SimpleMemoryCache, RedisCache
from aiocache.serializers import StringSerializer, PickleSerializer

caches.set_config({
    'default': {
        'cache': "aiocache.SimpleMemoryCache",
        'serializer': {
            'class': "aiocache.serializers.StringSerializer"
        }
    },
    'redis_alt': {
        'cache': "aiocache.RedisCache",
        'endpoint': "127.0.0.1",
        'port': 6379,
        'timeout': 1,
        'serializer': {
            'class': "aiocache.serializers.PickleSerializer"
        },
        'plugins': [
            {'class': "aiocache.plugins.HitMissRatioPlugin"},
            {'class': "aiocache.plugins.TimingPlugin"}
        ]
    }
})


async def default_cache():
    cache = caches.get('default')   # This always returns the same instance
    await cache.set("key", "value")

    assert await cache.get("key") == "value"
    assert isinstance(cache, SimpleMemoryCache)
    assert isinstance(cache.serializer, StringSerializer)


async def alt_cache():
    # This generates a new instance every time! You can also use `caches.create('alt')`
    # or even `caches.create('alt', namespace="test", etc...)` to override extra args
    cache = caches.create(**caches.get_alias_config('redis_alt'))
    await cache.set("key", "value")

    assert await cache.get("key") == "value"
    assert isinstance(cache, RedisCache)
    assert isinstance(cache.serializer, PickleSerializer)
    assert len(cache.plugins) == 2
    assert cache.endpoint == "127.0.0.1"
    assert cache.timeout == 1
    assert cache.port == 6379
    await cache.close()


def test_alias():
    loop = asyncio.get_event_loop()
    loop.run_until_complete(default_cache())
    loop.run_until_complete(alt_cache())

    cache = RedisCache()
    loop.run_until_complete(cache.delete("key"))
    loop.run_until_complete(cache.close())

    loop.run_until_complete(caches.get('default').close())


if __name__ == "__main__":
    test_alias()

When you do caches.get('alias_name'), the cache instance is built lazily the first time. Next accesses will return the same instance. If instead of reusing the same instance, you need a new one every time, use caches.create('alias_name'). One of the advantages of caches.create is that it accepts extra args that then are passed to the cache constructor. This way you can override args like namespace, endpoint, etc.