This library is an extension of buffer-backed-object with a more OO implementation and a replaceable buffer.
import * as BBO from "buffer-backed-object"
import { BinaryMessage } from "@dimensionalpocket/binary-message"
class MyBinaryMessage extends BinaryMessage {
constructor (size = null, buffer = null) {
// Define your schema as if you were using buffer-backed-object (BBO).
// If not provided, size is automatically calculated (if possible) based on provided schema.
super({
id: BBO.BufferBackedObject.Uint16({ endianness: "big" }),
position: BBO.NestedBufferBackedObject({
x: BBO.Float32(),
y: BBO.Float32(),
z: BBO.Float32(),
}),
normal: BBO.NestedBufferBackedObject({
x: BBO.Float32(),
y: BBO.Float32(),
z: BBO.Float32(),
}),
textureId: BBO.Uint8(),
})
if (buffer) this.buffer = buffer
}
}
// Initialize an instance of your object.
// It will automatically create a buffer if you don't provide one.
var message = new MyMessage()
// Access message properties as you would normally do with BBO.
message.id
message.position.x
message.normal.y
message.textureId
// Get the underlying buffer.
message.buffer
// Replace the underlying buffer.
// Object properties will then return the values from new buffer.
message.buffer = new ArrayBuffer(...)The primary use case for this would be Web Worker messaging performance.
Being able to replace the buffer would allow a single instance of your message object to be reused, without the overhead of instancing a new one.
// ---------------------
// ---- CLIENT SIDE ----
// ---------------------
// Create a persistent client message object with an 8MB size.
// It will be reused every time the client sends a message to the worker.
const clientMessage = new MyBinaryMessage(1024 * 1024 * 8)
console.log(clientMessage.buffer.byteLength) // 8388608
// Fill your message properties with data.
clientMessage.id = 123
clientMessage.position.x = 456
// etc
// Transfer the underlying buffer to a web worker.
worker.postMessage(clientMessage.buffer, [clientMessage.buffer]);
// The buffer will be gone after this.
console.log(clientMessage.buffer.byteLength) // 0
// clientMessage properties will be reset, but the instance will still be alive.
// You can then either provide a new buffer...
clientMessage.buffer = new ArrayBuffer(clientMessage.byteLength)
// ... or recreate it.
clientMessage.resetBuffer()
console.log(clientMessage.buffer.byteLength) // 8388608
// Then reuse the object normally.
clientMessage.id = 789
clientMessage.position.x = 123
// etc
// -------------------------
// ---- WEB WORKER SIDE ----
// -------------------------
// Create a persistent message object with an 8MB size
// that will "parse" buffers from the client.
const workerMessage = new MyBinaryMessage(1024 * 1024 * 8)
console.log(workerMessage.buffer.byteLength) // 8388608
self.onmessage = function (transferredArrayBuffer) => {
workerMessage.buffer = transferredArrayBuffer
// You can then read the message properties
// from the transferred buffer.
workerMessage.id // <= 123
workerMessage.position.x // <= 456
})MIT