Redis Cache

redis_example.py

import redis

class ResourceCache(object):
    """Uses a local directory as a store for cached files.
    """
    def __init__(self, redis_host='localhost', redis_port=6379, redis_db=0):
        self.cache = redis.Redis(host=redis_host, port=redis_port, db=redis_db)

    def get_resource_params(self, resource_key):
        if self.cache.sismember("resource_key", resource_key):
            resource_type = self.cache.hget("resource_key:%s" % resource_key, "resource_type")
            etag = self.cache.hget("resource_key:%s" % resource_key, "etag")
            last_modified = self.cache.hget("resource_key:%s" % resource_key, "last_modified")
            return resource_key, resource_type, etag, last_modified
        else:
            return None, None, None, None

    def update_resource_params(self, resource_key, resource_type, etag, last_modified):
        if etag is None:
            etag = ""
        if last_modified is None:
            last_modified = ""
        self.cache.sadd("resource_key", resource_key)
        self.cache.hset("resource_key:%s" % resource_key, "resource_type", resource_type)
        self.cache.hset("resource_key:%s" % resource_key, "etag", etag)
        self.cache.hset("resource_key:%s" % resource_key, "last_modified", last_modified)

    def delete_resource(self, resource_key):
        if self.cache.sismembers("resource_key", resource_key):
            self.cache.srem("resource_key", resource_key)
            self.cache.delete("resource_key:%s" % resource_key)

if __name__ == "__main__":
    r = ResourceCache()
    #~r.update_resource_params('EEW34BT-Eb-twoXwfl_S9A==', 'mp3',
                            #~'flask-1306167922.0-20375-2401376856',
                            #~'Mon, 23 May 2011 16:25:22 GMT')
    r.update_resource_params('EEW34BT-Eb-twoXwfl_S9A==', 'mp3',
                            None,
                            None)
    print r.get_resource_params('EEW34BT-Eb-twoXwfl_S9A==')
    print r.get_resource_params('EEW34BT-Eb-twoXwfl_XS9A==')