I have a use case to send the hashcode of the payload along with the payload in the request.
My Client is Ruby but Servers are both Rails and Node.
What is the best way to create a hash code for the payload (any Ruby HashMap)?
How can I create the same hashcode on the other server?
>> x = {:name=>"John", :age=>30, :cars=>{:car1=>"Ford", :car2=>"BMW", :car3=>"Fiat"}}
>> x.hash
-4250725627701565010
This is not possible.
The only guarantees that Ruby makes about the hashcode are:
eql? have the same hashcode.Integer. It may be truncated to a fixed-width integer in certain methods.In particular, the following are not guaranteed:
In fact, several Ruby implementations randomize hashcodes for security purposes.
In other words, there isn't even a way in Ruby to know what the hashcode for an object will be at runtime, so there is most definitely no way to know that in ECMAScript.
You could use an alternative hashing algorithm, such as SHA256, this will give the same result in Ruby and Javascript.
One must be careful however, the hashes will only match if the inputs are exactly the same.
Ruby
require 'json'
require 'digest/sha2'
x = {:name=>"John", :age=>30, :cars=>{:car1=>"Ford", :car2=>"BMW", :car3=>"Fiat"}}
json = JSON.generate(x)
print "Hash: " + (Digest::SHA2.hexdigest json)
Node.js
const crypto = require("crypto");
const x = { name: "John", age: 30, cars: { car1: "Ford", car2: "BMW", car3: "Fiat" }};
const json = JSON.stringify(x);
const hash = crypto.createHash("SHA256").update(json, "utf8").digest("hex");
console.log("Hash:", hash);
We'll get the same result in both cases:
Hash: 1b5299251d2e9bf775bc4cf34a017c829d93866ac9563b04e2b14b6b3d291067
JSON.stringify