REDIS file caching

redisfile.py

import hashlib
from redis import Redis

#
# automatically cache file access to a redis instance 
# check if file changed via md5
#

class RedisFileManager(object):
    """ cache file access to a redis instance """
    def __init__(self, *args, **kwargs):
        self.redis = Redis(*args, **kwargs)

    def get(self, path):
        file_key = self._key(path)
        contents = self.redis.get(file_key)
        if contents is None:
            # cache new file in redis
            contents = open(path, 'rb').read()
            self.redis.set(file_key, contents)
        return contents

    def delete(self, path):
        self.redis.delete(self._key(path))

    def _key(self, path):
        return 'file:%s' % self._md5sum(path)

    def _md5sum(self, path):
        """ get file md5 quickly """
        md5 = hashlib.md5()
        with open(path,'rb') as f: 
            for chunk in iter(lambda: f.read(128*md5.block_size), b''): 
                 md5.update(chunk)
        return md5.hexdigest()


srv = RedisFileManager(host='redishost.com', port=6379, password='myPassWord')
data = srv.get('/path/to/local/file')
print "GOT CONTENT", len(data)

If you have to get the md5 checksum of the file to generate its lookup key, wouldn't it be faster to just read the file?