MessagePack Processing

ES-Runtime provides high-performance native MessagePack parsing via the runtime:serialization module, backed by rmp-serde.

Parsing MessagePack

Use MessagePack.decode to convert a MessagePack byte array directly into a JavaScript object.

JavaScript

import { MessagePack } from "runtime:serialization";

const msgpackBytes = new Uint8Array([0x81, 0xa4, 0x75, 0x73, 0x65, 0x72, 0x82, 0xa2, 0x69, 0x64, 0x01, 0xa4, 0x6e, 0x61, 0x6d, 0x65, 0xa5, 0x41, 0x6c, 0x69, 0x63, 0x65]);

const parsed = MessagePack.decode(msgpackBytes);
console.log(parsed.user.name); // "Alice"
console.log(parsed.user.id);   // 1

Validating MessagePack

Use MessagePack.validate to check if a MessagePack byte array is well-formed.

JavaScript

import { MessagePack } from "runtime:serialization";

const msgpackBytes = new Uint8Array([0x81, 0xa4, 0x75, 0x73, 0x65, 0x72, 0x82, 0xa2, 0x69, 0x64, 0x01, 0xa4, 0x6e, 0x61, 0x6d, 0x65, 0xa5, 0x41, 0x6c, 0x69, 0x63, 0x65]);

if (MessagePack.validate(msgpackBytes)) {
  console.log("MessagePack is valid!");
}

const invalidBytes = new Uint8Array([0xc1]);
const result = MessagePack.validate(invalidBytes, { detailed: true });
console.log(result.valid); // false
console.log(result.error); // "Validation failed: ..."

Building MessagePack

Use MessagePack.encode to convert a JavaScript object back into a MessagePack byte array.

JavaScript

import { MessagePack } from "runtime:serialization";

const obj = {
  user: {
    id: 1,
    name: "Alice"
  }
};

const built = MessagePack.encode(obj);
console.log(built instanceof Uint8Array); // true