enhanced_txredis.py

# Enhanced txRedis that handles setting up auth and DB
class ERedis(Redis):
    
    def __init__(self, db=None, charset='utf8', errors='strict', passwd=None):
        self.charset = charset
        self.db = db
        self.errors = errors
        self._buffer = ''
        self._bulk_length = None
        self._disconnected = False
        self._multi_bulk_length = None
        self._multi_bulk_reply = []
        self._request_queue = deque()
        self.passwd = passwd
        
        print self.db
    
    def connectionMade(self):
        Redis.connectionMade(self)
        
        # Authenticate if requested, and select DB
        if self.passwd:
            return self.init_auth().addCallback(self.select_db)
        else:
            return self.select_db()
    
    @defer.inlineCallbacks
    def init_auth(self, *args):
        while self.transport == None:
            yield task.deferLater(reactor, 1.0, defer.passthru, None)
         
        try:
            res = yield self.auth(self.passwd)
        except Exception, e:
            raise Exception("Unexpected error authenticating with Redis backend: %s" % str(e))
        if res != "OK":
            raise Exception("Invalid Redis password supplied for authentication.")
    
    @defer.inlineCallbacks
    def select_db(self, *args):
        while self.transport == None:
            yield task.deferLater(reactor, 1.0, defer.passthru, None)
        
        try:
            res = yield self.select(self.db)
            res = str(res)
            
            if res == "operation not permitted":
                raise Exception("Error selecting DB %s. Redis password required." % self.redis_db)
            elif res == "invalid DB index":
                raise Exception("Invalid DB index (%s)." % self.redis_db)
            elif res != "OK":
                raise Exception("Unexpected error selecting DB %s." % self.redis_db)
        except error.ConnectionRefusedError, e:
            raise Exception("Unexpected connection error selecting Redis DB %s: %s" % (self.redis_db,
                                                                                       str(e)))
        return