lib/web_ui/lib/hash_codes.dart

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

part of ui;

class _HashEnd {
  const _HashEnd();
}

const _HashEnd _hashEnd = _HashEnd();

// Jenkins hash function, optimized for small integers.
//
// Borrowed from the dart sdk: sdk/lib/math/jenkins_smi_hash.dart.
abstract class _Jenkins {
  // This class is not meant to be instantiated or extended; this constructor
  // prevents instantiation and extension.
  _Jenkins._();

  static int combine(int hash, Object? o) {
    assert(o is! Iterable);
    hash = 0x1fffffff & (hash + o.hashCode);
    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
    hash = hash ^ (hash >> 6);
    return hash;
  }

  static int finish(int hash) {
    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
    hash = hash ^ (hash >> 11);
    hash = 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
    return hash;
  }
}

int hashValues(
  Object? arg01,
  Object? arg02, [
  Object? arg03 = _hashEnd,
  Object? arg04 = _hashEnd,
  Object? arg05 = _hashEnd,
  Object? arg06 = _hashEnd,
  Object? arg07 = _hashEnd,
  Object? arg08 = _hashEnd,
  Object? arg09 = _hashEnd,
  Object? arg10 = _hashEnd,
  Object? arg11 = _hashEnd,
  Object? arg12 = _hashEnd,
  Object? arg13 = _hashEnd,
  Object? arg14 = _hashEnd,
  Object? arg15 = _hashEnd,
  Object? arg16 = _hashEnd,
  Object? arg17 = _hashEnd,
  Object? arg18 = _hashEnd,
  Object? arg19 = _hashEnd,
  Object? arg20 = _hashEnd,
]) {
  int result = 0;
  result = _Jenkins.combine(result, arg01);
  result = _Jenkins.combine(result, arg02);
  if (arg03 != _hashEnd) {
    result = _Jenkins.combine(result, arg03);
    if (arg04 != _hashEnd) {
      result = _Jenkins.combine(result, arg04);
      if (arg05 != _hashEnd) {
        result = _Jenkins.combine(result, arg05);
        if (arg06 != _hashEnd) {
          result = _Jenkins.combine(result, arg06);
          if (arg07 != _hashEnd) {
            result = _Jenkins.combine(result, arg07);
            if (arg08 != _hashEnd) {
              result = _Jenkins.combine(result, arg08);
              if (arg09 != _hashEnd) {
                result = _Jenkins.combine(result, arg09);
                if (arg10 != _hashEnd) {
                  result = _Jenkins.combine(result, arg10);
                  if (arg11 != _hashEnd) {
                    result = _Jenkins.combine(result, arg11);
                    if (arg12 != _hashEnd) {
                      result = _Jenkins.combine(result, arg12);
                      if (arg13 != _hashEnd) {
                        result = _Jenkins.combine(result, arg13);
                        if (arg14 != _hashEnd) {
                          result = _Jenkins.combine(result, arg14);
                          if (arg15 != _hashEnd) {
                            result = _Jenkins.combine(result, arg15);
                            if (arg16 != _hashEnd) {
                              result = _Jenkins.combine(result, arg16);
                              if (arg17 != _hashEnd) {
                                result = _Jenkins.combine(result, arg17);
                                if (arg18 != _hashEnd) {
                                  result = _Jenkins.combine(result, arg18);
                                  if (arg19 != _hashEnd) {
                                    result = _Jenkins.combine(result, arg19);
                                    if (arg20 != _hashEnd) {
                                      result = _Jenkins.combine(result, arg20);
                                      // I can see my house from here!
                                    }
                                  }
                                }
                              }
                            }
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return _Jenkins.finish(result);
}

int hashList(Iterable<Object?>? arguments) {
  int result = 0;
  if (arguments != null) {
    for (final Object? argument in arguments)
      result = _Jenkins.combine(result, argument);
  }
  return _Jenkins.finish(result);
}