Function readBigUInt64BE

lib/internal/buffer.js:118–136

(offset = 0)

}

function readBigUInt64BE(offset = 0) {
  validateNumber(offset, 'offset');
  const first = this[offset];
  const last = this[offset + 7];
  if (first === undefined || last === undefined)
    boundsError(offset, this.length - 8);

  const hi = first * 2 ** 24 +
    this[++offset] * 2 ** 16 +
    this[++offset] * 2 ** 8 +
    this[++offset];

  const lo = this[++offset] * 2 ** 24 +
    this[++offset] * 2 ** 16 +
    this[++offset] * 2 ** 8 +
    last;

  return (BigInt(hi) << 32n) + BigInt(lo);
}

function readBigInt64LE(offset = 0) {
  validateNumber(offset, 'offset');