mine method

MineResult mine(String data, BigInt target, { int maxAttempts = 1000000, bool shouldStop()?, })

Mine data until hash <= target or maxAttempts reached.

shouldStop is checked every iteration and may be used to cancel long-running mining from a caller (for example a UI or timeout).

Implementation

MineResult mine(
  String data,
  BigInt target, {
  int maxAttempts = 1000000,
  bool Function()? shouldStop,
}) {
  if (target < BigInt.zero) throw ArgumentError('target must be >= 0');
  BigInt bestHash = BigInt.from(1) << 255; // large sentinel
  int bestNonce = 0;
  for (var i = 0; i < maxAttempts; i++) {
    if (shouldStop != null && shouldStop()) {
      return MineResult(bestNonce, bestHash, i, success: false);
    }
    final nonce = _rand.nextInt(1 << 30);
    final h = hashFn(data, nonce);
    if (h < bestHash) {
      bestHash = h;
      bestNonce = nonce;
    }
    if (h <= target) return MineResult(nonce, h, i + 1, success: true);
  }
  return MineResult(bestNonce, bestHash, maxAttempts, success: false);
}