objectid-split.js

function analyseObjectId(/** @type {import('bson').ObjectId} */ oid) {
  const randomidBuffer = Buffer.from(
    oid.buffer.buffer,
    oid.buffer.byteOffset + 4,
    5,
  );
  const counterBuffer = Buffer.alloc(4);
  oid.buffer.copy(counterBuffer, 1, 9);
  return {
    timestamp: oid.buffer.readInt32BE(0),
    randomprocid: randomidBuffer.toString("hex"),
    counter: counterBuffer.readUInt32BE(),
  };
}