freezer/lib/utils.dart

import 'dart:typed_data';

class Utils {
  static List<int> splitDigits(int number) {
    final digits = <int>[];
    while (number != 0) {
      digits.add(number % 10);
      number = number ~/ 10;
    }

    return digits;
  }

  static Uint8List serializeBigInt(BigInt bi) {
    Uint8List array = Uint8List((bi.bitLength / 8).ceil());
    for (int i = 0; i < array.length; i++) {
      array[i] = (bi >> (i * 8)).toUnsigned(8).toInt();
    }
    return array;
  }

  static BigInt deserializeBigInt(Uint8List array) {
    var bi = BigInt.zero;
    for (var byte in array.reversed) {
      bi <<= 8;
      bi |= BigInt.from(byte);
    }
    return bi;
  }

  /// FOR ISAR, FROM ISAR DOCUMENTATION
  /// FNV-1a 64bit hash algorithm optimized for Dart Strings
  static int fastHash(String string) {
    var hash = 0xcbf29ce484222325;

    var i = 0;
    while (i < string.length) {
      final codeUnit = string.codeUnitAt(i++);
      hash ^= codeUnit >> 8;
      hash *= 0x100000001b3;
      hash ^= codeUnit & 0xFF;
      hash *= 0x100000001b3;
    }

    return hash;
  }
}