protobuf/lib/src/protobuf/pb_list.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:collection' show ListBase;
import 'dart:math' as math;

import 'internal.dart';
import 'utils.dart';

@pragma('dart2js:tryInline')
@pragma('vm:prefer-inline')
@pragma('wasm:prefer-inline')
PbList<E> newPbList<E>({CheckFunc<E>? check}) => PbList._(check: check);

@pragma('dart2js:tryInline')
@pragma('vm:prefer-inline')
@pragma('wasm:prefer-inline')
PbList<E> newUnmodifiablePbList<E>({CheckFunc<E>? check}) =>
    PbList._unmodifiable();

/// A [ListBase] implementation used for protobuf `repeated` fields.
class PbList<E> extends ListBase<E> {
  /// The actual list storing the elements.
  ///
  /// Note: We want only one [List] implementation class to be stored here to
  /// make sure the list operations are monomorphic and can be inlined. In
  /// constructors make sure initializers for this field all return the same
  /// implementation class. (e.g. `_GrowableList` on the VM)
  final List<E> _wrappedList;

  /// A growable list, to be used in `unmodifiable` constructor to avoid
  /// allocating a list every time.
  ///
  /// We can't use `const []` as it makes the `_wrappedList` field polymorphic.
  static final _emptyList = <Never>[];

  final CheckFunc<E>? _check;

  bool _isReadOnly = false;

  bool get isFrozen => _isReadOnly;

  PbList._({CheckFunc<E>? check}) : _wrappedList = <E>[], _check = check;

  PbList._unmodifiable()
    : _wrappedList = _emptyList,
      _check = null,
      _isReadOnly = true;

  @override
  @pragma('dart2js:never-inline')
  void add(E element) {
    _checkModifiable('add');
    if (_check != null) {
      _check(element);
    }
    _wrappedList.add(element);
  }

  @pragma('dart2js:tryInline')
  @pragma('vm:prefer-inline')
  @pragma('wasm:prefer-inline')
  void _addUnchecked(E element) {
    _wrappedList.add(element);
  }

  @override
  @pragma('dart2js:never-inline')
  void addAll(Iterable<E> iterable) {
    _checkModifiable('addAll');
    if (_check != null) {
      for (final e in iterable) {
        _check(e);
        _addUnchecked(e);
      }
    } else {
      _wrappedList.addAll(iterable);
    }
  }

  @override
  Iterable<E> get reversed => _wrappedList.reversed;

  @override
  void sort([int Function(E a, E b)? compare]) {
    _checkModifiable('sort');
    _wrappedList.sort(compare);
  }

  @override
  void shuffle([math.Random? random]) {
    _checkModifiable('shuffle');
    _wrappedList.shuffle(random);
  }

  @override
  @pragma('dart2js:never-inline')
  void clear() {
    _checkModifiable('clear');
    _wrappedList.clear();
  }

  @override
  void insert(int index, E element) {
    _checkModifiable('insert');
    if (_check != null) {
      _check(element);
    }
    _wrappedList.insert(index, element);
  }

  @override
  void insertAll(int index, Iterable<E> iterable) {
    _checkModifiable('insertAll');
    if (_check != null) {
      _wrappedList.insertAll(
        index,
        iterable.map((E e) {
          _check(e);
          return e;
        }),
      );
    } else {
      _wrappedList.insertAll(index, iterable);
    }
  }

  @override
  void setAll(int index, Iterable<E> iterable) {
    _checkModifiable('setAll');
    if (_check != null) {
      _wrappedList.setAll(
        index,
        iterable.map((E e) {
          _check(e);
          return e;
        }),
      );
    } else {
      _wrappedList.setAll(index, iterable);
    }
  }

  @override
  bool remove(Object? element) {
    _checkModifiable('remove');
    return _wrappedList.remove(element);
  }

  @override
  E removeAt(int index) {
    _checkModifiable('removeAt');
    return _wrappedList.removeAt(index);
  }

  @override
  E removeLast() {
    _checkModifiable('removeLast');
    return _wrappedList.removeLast();
  }

  @override
  void removeWhere(bool Function(E element) test) {
    _checkModifiable('removeWhere');
    return _wrappedList.removeWhere(test);
  }

  @override
  void retainWhere(bool Function(E element) test) {
    _checkModifiable('retainWhere');
    return _wrappedList.retainWhere(test);
  }

  @override
  void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
    _checkModifiable('setRange');
    if (_check != null) {
      _wrappedList.setRange(
        start,
        end,
        iterable.skip(skipCount).map((E e) {
          _check(e);
          return e;
        }),
        0,
      );
    } else {
      _wrappedList.setRange(start, end, iterable, skipCount);
    }
  }

  @override
  void removeRange(int start, int end) {
    _checkModifiable('removeRange');
    _wrappedList.removeRange(start, end);
  }

  @override
  void fillRange(int start, int end, [E? fill]) {
    _checkModifiable('fillRange');
    if (_check != null) {
      _check(fill);
    }
    _wrappedList.fillRange(start, end, fill);
  }

  @override
  void replaceRange(int start, int end, Iterable<E> newContents) {
    _checkModifiable('replaceRange');
    if (_check != null) {
      _wrappedList.replaceRange(
        start,
        end,
        newContents.map((E e) {
          _check(e);
          return e;
        }),
      );
    } else {
      _wrappedList.replaceRange(start, end, newContents);
    }
  }

  @override
  int get length => _wrappedList.length;

  @override
  bool get isEmpty => _wrappedList.isEmpty;

  @override
  bool get isNotEmpty => _wrappedList.isNotEmpty;

  @override
  @pragma('dart2js:never-inline')
  Iterator<E> get iterator => _wrappedList.iterator;

  @override
  set length(int newLength) {
    _checkModifiable('set length');
    if (newLength > length) {
      throw UnsupportedError('Extending protobuf lists is not supported');
    }
    _wrappedList.length = newLength;
  }

  @override
  E operator [](int index) => _wrappedList[index];

  @override
  void operator []=(int index, E value) {
    _checkModifiable('set element');
    if (_check != null) {
      _check(value);
    }
    _wrappedList[index] = value;
  }

  @override
  bool operator ==(Object other) =>
      other is PbList && areListsEqual(other, this);

  @override
  int get hashCode => HashUtils.hashObjects(_wrappedList);

  void freeze() {
    if (_isReadOnly) {
      return;
    }

    _isReadOnly = true;

    // Per spec `repeated map<..>` and `repeated repeated ..` are not allowed
    // so we only check for messages
    if (_wrappedList.isNotEmpty && _wrappedList[0] is GeneratedMessage) {
      for (final elem in _wrappedList as Iterable<GeneratedMessage>) {
        elem.freeze();
      }
    }
  }

  void _checkModifiable(String methodName) {
    if (_isReadOnly) {
      _readOnlyError(methodName);
    }
  }

  static Never _readOnlyError(String methodName) {
    throw UnsupportedError("'$methodName' on a read-only list");
  }

  PbList<E> _deepCopy() {
    final newList = PbList<E>._(check: _check);
    final wrappedList = _wrappedList;
    final newWrappedList = newList._wrappedList;
    if (wrappedList.isNotEmpty) {
      if (wrappedList[0] is GeneratedMessage) {
        for (final message in wrappedList) {
          newWrappedList.add((message as GeneratedMessage).deepCopy() as E);
        }
      } else {
        newWrappedList.addAll(wrappedList);
      }
    }
    return newList;
  }
}

extension PbListInternalExtension<E> on PbList<E> {
  @pragma('dart2js:tryInline')
  @pragma('vm:prefer-inline')
  @pragma('wasm:prefer-inline')
  void checkModifiable(String methodName) => _checkModifiable(methodName);

  @pragma('dart2js:tryInline')
  @pragma('vm:prefer-inline')
  @pragma('wasm:prefer-inline')
  void addUnchecked(E element) => _addUnchecked(element);

  @pragma('dart2js:tryInline')
  @pragma('vm:prefer-inline')
  @pragma('wasm:prefer-inline')
  PbList<E> deepCopy() => _deepCopy();
}