Function readBigUInt64LE

lib/internal/buffer.js:98–116

(offset = 0)

// Read integers.
function readBigUInt64LE(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 lo = first +
    this[++offset] * 2 ** 8 +
    this[++offset] * 2 ** 16 +
    this[++offset] * 2 ** 24;

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

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

function readBigUInt64BE(offset = 0) {
  validateNumber(offset, 'offset');