node.js store objects in redis


Question

Here is the thing - I want to store native JS (node.js) objects (flash sockets references) in redis under a certain key. When I do that with simple client.set() it's stored as a string. When I try to get value I get [object Object] - just a string.

Any chance to get this working? Here's my code:

  addSocket : function(sid, socket) {
    client.set(sid, socket);
  },

  getSocket : function(sid) {
    client.get(sid, function(err, reply) {
      // cant't get an object here. All I get is useless string
    });
  },
1
45
1/1/2012 7:05:50 PM

Accepted Answer

Downvoters: the context here is SET command and ability to store arbitrary objects.

No, you can't do that. You should accept the fact that Redis stores everything as a string (the protocol is text-based, after all). Redis may perform some optimizations and convert some values to integers, but that's its business, not yours.

If you want to store arbitrary objects in Redis, make sure that you serialize them before saving and de-serialize after retrieving.

I'm not sure if you can do that with socket objects, though. They simply describe a system resource (an open connection), after all (TCP sockets, for example). If you manage to serialize the description and deserialize it on another machine, that other machine won't have the connection.

33
5/5/2018 4:31:48 PM

Since the socket is of type Object, you need to convert the object to a string before storing and when retrieving the socket, need to convert it back to an object.

You can use

JSON.stringify(socket) 

to convert to a string and

JSON.parse(socketstr) 

to convert back to an object.

Edit:

Since the release of version 2.0.0, we are able to store objects as hashes into Redis.

client.hmset("hosts", "mjr", "1", "another", "23", "home", "1234");

client.hgetall("hosts", function (err, obj) {
    console.dir(obj);
});

https://redis.io/commands/hset

https://github.com/NodeRedis/node_redis


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