Storing string data with compressed (buffer) data together on Redis - node.js

Question

Is there any chance to store Buffer data with a string data together on Redis.
Pseudo code:
// Data compression
var user = { name: "Xyz" }
var userString = JSON.stringify(user)
var userBuffer = new Buffer(userString, "utf8")
var compressed = zlib.gzip(userBuffer)
// Adding data onto Redis
var data = { id: 1, compressed: compressed }
var dataString = JSON.stringify(data)
redis.set("test", dataString)
Although it seems impossible I wanna ask.
Is there any chance to store compressed data with string together?
Edit:
After storing compressed data with uncompressed data in the same key, I cannot decompress the user data above.
Pseudo code:
var dataString = redis.get("test")
var data = JSON.parse(dataString)
console.log(data)
// writes { id:1, compressed: { type: Buffer, data: [31, 139, 8...] } }
var compressed = data.compressed
var user = zlib.gunzip(compressed)
// user would be undefined here

Answer 1

const zlib = require('zlib');
const redis = require('redis').createClient();
var user = { name: "Xyz" }
var userString = JSON.stringify(user)
var userBuffer = new Buffer(userString, "utf8")
var compressed = zlib.gzipSync(userBuffer)
var data = { id: 1, compressed: compressed }
var dataString = JSON.stringify(data)
console.log('Compressed', dataString);
redis.set('mykey', dataString, err => {
if (err) throw err;
redis.get('mykey', (err, dataString) => {
if (err) throw err;
var data = JSON.parse(dataString)
var buffer = Buffer.from(data.compressed);
var uncompressed = zlib.gunzipSync(buffer);
console.log('Uncompressed', JSON.parse(uncompressed));
redis.end(false);
})
});
The key is to convert the string-representation of the Buffer back to a proper instance before decompressing it (using Buffer.from()).
However, the JSON-representation of a Buffer isn't very concise, so you probably should look into an alternative way of storing the data in Redis (one where you don't have to stringify the buffer). Perhaps using a hash.