Share the JavaScript based LinkedHashMap implementation between constant maps and the LinkedHashMap…

sdk/lib/_internal/compiler/js_lib/collection_patch.dart

 // Copyright (c) 2013, 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.
 
 // Patch file for dart:collection classes.
 import 'dart:_foreign_helper' show JS;
 import 'dart:_js_helper' show
-    fillLiteralMap, InternalMap, NoInline, NoThrows, patch;
+    fillLiteralMap, InternalMap, NoInline, NoThrows, patch, JsLinkedHashMap,
+    LinkedHashMapCell, LinkedHashMapKeyIterable, LinkedHashMapKeyIterator;
 
 @patch
 class HashMap<K, V> {
   @patch
   factory HashMap({ bool equals(K key1, K key2),
                     int hashCode(K key),
                     bool isValidKey(potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
@@ skipping 465 matching lines @@
 
 @patch
 class LinkedHashMap<K, V> {
   @patch
   factory LinkedHashMap({ bool equals(K key1, K key2),
                           int hashCode(K key),
                           bool isValidKey(potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
-          return new _LinkedHashMap<K, V>();
+          return new JsLinkedHashMap<K, V>();
         }
         hashCode = _defaultHashCode;
       } else {
         if (identical(identityHashCode, hashCode) &&
             identical(identical, equals)) {
           return new _LinkedIdentityHashMap<K, V>();
         }
         if (equals == null) {
           equals = _defaultEquals;
         }
       }
     } else {
       if (hashCode == null) {
         hashCode = _defaultHashCode;
       }
       if (equals == null) {
         equals = _defaultEquals;
       }
     }
     return new _LinkedCustomHashMap<K, V>(equals, hashCode, isValidKey);
   }
 
   @patch
   factory LinkedHashMap.identity() = _LinkedIdentityHashMap<K, V>;
 
   // Private factory constructor called by generated code for map literals.
   @NoInline()
   factory LinkedHashMap._literal(List keyValuePairs) {
-    return fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>());
+    return fillLiteralMap(keyValuePairs, new JsLinkedHashMap<K, V>());
   }
 
   // Private factory constructor called by generated code for map literals.
   @NoThrows() @NoInline()
   factory LinkedHashMap._empty() {
-    return new _LinkedHashMap<K, V>();
+    return new JsLinkedHashMap<K, V>();
   }
 }
 
-class _LinkedHashMap<K, V> implements LinkedHashMap<K, V>, InternalMap {
-  int _length = 0;
-
-  // The hash map contents are divided into three parts: one part for
-  // string keys, one for numeric keys, and one for the rest. String
-  // and numeric keys map directly to their linked cells, but the rest
-  // of the entries are stored in bucket lists of the form:
-  //
-  //    [cell-0, cell-1, ...]
-  //
-  // where all keys in the same bucket share the same hash code.
-  var _strings;
-  var _nums;
-  var _rest;
-
-  // The keys and values are stored in cells that are linked together
-  // to form a double linked list.
-  LinkedHashMapCell _first;
-  LinkedHashMapCell _last;
-
-  // We track the number of modifications done to the key set of the
-  // hash map to be able to throw when the map is modified while being
-  // iterated over.
-  int _modifications = 0;
-
-  _LinkedHashMap();
-
-
-  int get length => _length;
-  bool get isEmpty => _length == 0;
-  bool get isNotEmpty => !isEmpty;
-
-  Iterable<K> get keys {
-    return new LinkedHashMapKeyIterable<K>(this);
-  }
-
-  Iterable<V> get values {
-    return new MappedIterable<K, V>(keys, (each) => this[each]);
-  }
-
-  bool containsKey(Object key) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) return false;
-      LinkedHashMapCell cell = _getTableEntry(strings, key);
-      return cell != null;
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) return false;
-      LinkedHashMapCell cell = _getTableEntry(nums, key);
-      return cell != null;
-    } else {
-      return _containsKey(key);
-    }
-  }
-
-  bool _containsKey(Object key) {
-    var rest = _rest;
-    if (rest == null) return false;
-    var bucket = _getBucket(rest, key);
-    return _findBucketIndex(bucket, key) >= 0;
-  }
-
-  bool containsValue(Object value) {
-    return keys.any((each) => this[each] == value);
-  }
-
-  void addAll(Map<K, V> other) {
-    other.forEach((K key, V value) {
-      this[key] = value;
-    });
-  }
-
-  V operator[](Object key) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) return null;
-      LinkedHashMapCell cell = _getTableEntry(strings, key);
-      return (cell == null) ? null : cell._value;
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) return null;
-      LinkedHashMapCell cell = _getTableEntry(nums, key);
-      return (cell == null) ? null : cell._value;
-    } else {
-      return _get(key);
-    }
-  }
-
-  V _get(Object key) {
-    var rest = _rest;
-    if (rest == null) return null;
-    var bucket = _getBucket(rest, key);
-    int index = _findBucketIndex(bucket, key);
-    if (index < 0) return null;
-    LinkedHashMapCell cell = JS('var', '#[#]', bucket, index);
-    return cell._value;
-  }
-
-  void operator[]=(K key, V value) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) _strings = strings = _newHashTable();
-      _addHashTableEntry(strings, key, value);
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) _nums = nums = _newHashTable();
-      _addHashTableEntry(nums, key, value);
-    } else {
-      _set(key, value);
-    }
-  }
-
-  void _set(K key, V value) {
-    var rest = _rest;
-    if (rest == null) _rest = rest = _newHashTable();
-    var hash = _computeHashCode(key);
-    var bucket = JS('var', '#[#]', rest, hash);
-    if (bucket == null) {
-      LinkedHashMapCell cell = _newLinkedCell(key, value);
-      _setTableEntry(rest, hash, JS('var', '[#]', cell));
-    } else {
-      int index = _findBucketIndex(bucket, key);
-      if (index >= 0) {
-        LinkedHashMapCell cell = JS('var', '#[#]', bucket, index);
-        cell._value = value;
-      } else {
-        LinkedHashMapCell cell = _newLinkedCell(key, value);
-        JS('void', '#.push(#)', bucket, cell);
-      }
-    }
-  }
-
-  V putIfAbsent(K key, V ifAbsent()) {
-    if (containsKey(key)) return this[key];
-    V value = ifAbsent();
-    this[key] = value;
-    return value;
-  }
-
-  V remove(Object key) {
-    if (_isStringKey(key)) {
-      return _removeHashTableEntry(_strings, key);
-    } else if (_isNumericKey(key)) {
-      return _removeHashTableEntry(_nums, key);
-    } else {
-      return _remove(key);
-    }
-  }
-
-  V _remove(Object key) {
-    var rest = _rest;
-    if (rest == null) return null;
-    var bucket = _getBucket(rest, key);
-    int index = _findBucketIndex(bucket, key);
-    if (index < 0) return null;
-    // Use splice to remove the [cell] element at the index and
-    // unlink the cell before returning its value.
-    LinkedHashMapCell cell = JS('var', '#.splice(#, 1)[0]', bucket, index);
-    _unlinkCell(cell);
-    // TODO(kasperl): Consider getting rid of the bucket list when
-    // the length reaches zero.
-    return cell._value;
-  }
-
-  void clear() {
-    if (_length > 0) {
-      _strings = _nums = _rest = _first = _last = null;
-      _length = 0;
-      _modified();
-    }
-  }
-
-  void forEach(void action(K key, V value)) {
-    LinkedHashMapCell cell = _first;
-    int modifications = _modifications;
-    while (cell != null) {
-      action(cell._key, cell._value);
-      if (modifications != _modifications) {
-        throw new ConcurrentModificationError(this);
-      }
-      cell = cell._next;
-    }
-  }
-
-  void _addHashTableEntry(var table, K key, V value) {
-    LinkedHashMapCell cell = _getTableEntry(table, key);
-    if (cell == null) {
-      _setTableEntry(table, key, _newLinkedCell(key, value));
-    } else {
-      cell._value = value;
-    }
-  }
-
-  V _removeHashTableEntry(var table, Object key) {
-    if (table == null) return null;
-    LinkedHashMapCell cell = _getTableEntry(table, key);
-    if (cell == null) return null;
-    _unlinkCell(cell);
-    _deleteTableEntry(table, key);
-    return cell._value;
-  }
-
-  void _modified() {
-    // Value cycles after 2^30 modifications. If you keep hold of an
-    // iterator for that long, you might miss a modification
-    // detection, and iteration can go sour. Don't do that.
-    _modifications = (_modifications + 1) & 0x3ffffff;
-  }
-
-  // Create a new cell and link it in as the last one in the list.
-  LinkedHashMapCell _newLinkedCell(K key, V value) {
-    LinkedHashMapCell cell = new LinkedHashMapCell(key, value);
-    if (_first == null) {
-      _first = _last = cell;
-    } else {
-      LinkedHashMapCell last = _last;
-      cell._previous = last;
-      _last = last._next = cell;
-    }
-    _length++;
-    _modified();
-    return cell;
-  }
-
-  // Unlink the given cell from the linked list of cells.
-  void _unlinkCell(LinkedHashMapCell cell) {
-    LinkedHashMapCell previous = cell._previous;
-    LinkedHashMapCell next = cell._next;
-    if (previous == null) {
-      assert(cell == _first);
-      _first = next;
-    } else {
-      previous._next = next;
-    }
-    if (next == null) {
-      assert(cell == _last);
-      _last = previous;
-    } else {
-      next._previous = previous;
-    }
-    _length--;
-    _modified();
-  }
-
-  static bool _isStringKey(var key) {
-    return key is String && key != '__proto__';
-  }
-
-  static bool _isNumericKey(var key) {
-    // Only treat unsigned 30-bit integers as numeric keys. This way,
-    // we avoid converting them to strings when we use them as keys in
-    // the JavaScript hash table object.
-    return key is num && JS('bool', '(# & 0x3ffffff) === #', key, key);
-  }
-
-  int _computeHashCode(var key) {
-    // We force the hash codes to be unsigned 30-bit integers to avoid
-    // issues with problematic keys like '__proto__'. Another option
-    // would be to throw an exception if the hash code isn't a number.
-    return JS('int', '# & 0x3ffffff', key.hashCode);
-  }
-
-  static _getTableEntry(var table, var key) {
-    return JS('var', '#[#]', table, key);
-  }
-
-  static void _setTableEntry(var table, var key, var value) {
-    assert(value != null);
-    JS('void', '#[#] = #', table, key, value);
-  }
-
-  static void _deleteTableEntry(var table, var key) {
-    JS('void', 'delete #[#]', table, key);
-  }
-
-  List _getBucket(var table, var key) {
-    var hash = _computeHashCode(key);
-    return JS('var', '#[#]', table, hash);
-  }
-
-  int _findBucketIndex(var bucket, var key) {
-    if (bucket == null) return -1;
-    int length = JS('int', '#.length', bucket);
-    for (int i = 0; i < length; i++) {
-      LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (cell._key == key) return i;
-    }
-    return -1;
-  }
-
-  static _newHashTable() {
-    // Create a new JavaScript object to be used as a hash table. Use
-    // Object.create to avoid the properties on Object.prototype
-    // showing up as entries.
-    var table = JS('var', 'Object.create(null)');
-    // Attempt to force the hash table into 'dictionary' mode by
-    // adding a property to it and deleting it again.
-    var temporaryKey = '<non-identifier-key>';
-    _setTableEntry(table, temporaryKey, table);
-    _deleteTableEntry(table, temporaryKey);
-    return table;
-  }
-
-  String toString() => Maps.mapToString(this);
-}
-
-class _LinkedIdentityHashMap<K, V> extends _LinkedHashMap<K, V> {
-  int _computeHashCode(var key) {
+class _LinkedIdentityHashMap<K, V> extends JsLinkedHashMap<K, V> {
+  int internalComputeHashCode(var key) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', identityHashCode(key));
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int internalFindBucketIndex(var bucket, var key) {

[sra1, 2015/05/15 22:59:33]

Can this be rewritten to avoid public names that are not part of an interface?

[Johnni Winther, 2015/05/18 07:11:30]

If not, maybe we should make named of injected members implicitly private within
the internal libraries.

     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
       LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (identical(cell._key, key)) return i;
+      if (identical(cell.key, key)) return i;
     }
     return -1;
   }
 }
 
-class _LinkedCustomHashMap<K, V> extends _LinkedHashMap<K, V> {
+class _LinkedCustomHashMap<K, V> extends JsLinkedHashMap<K, V> {
   final _Equality<K> _equals;
   final _Hasher<K> _hashCode;
   final _Predicate _validKey;
   _LinkedCustomHashMap(this._equals, this._hashCode,
                        bool validKey(potentialKey))
       : _validKey = (validKey != null) ? validKey : ((v) => v is K);
 
   V operator[](Object key) {
     if (!_validKey(key)) return null;
-    return super._get(key);
+    return super.internalGet(key);
   }
 
   void operator[]=(K key, V value) {
-    super._set(key, value);
+    super.internalSet(key, value);
   }
 
   bool containsKey(Object key) {
     if (!_validKey(key)) return false;
-    return super._containsKey(key);
+    return super.internalContainsKey(key);
   }
 
   V remove(Object key) {
     if (!_validKey(key)) return null;
-    return super._remove(key);
+    return super.internalRemove(key);
   }
 
-  int _computeHashCode(var key) {
+  int internalComputeHashCode(var key) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', _hashCode(key));
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int internalFindBucketIndex(var bucket, var key) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
       LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (_equals(cell._key, key)) return i;
+      if (_equals(cell.key, key)) return i;
     }
     return -1;
   }
 }
 
-class LinkedHashMapCell {
-  final _key;
-  var _value;
-
-  LinkedHashMapCell _next;
-  LinkedHashMapCell _previous;
-
-  LinkedHashMapCell(this._key, this._value);
-}
-
-class LinkedHashMapKeyIterable<E> extends IterableBase<E>
-                                  implements EfficientLength {
-  final _map;
-  LinkedHashMapKeyIterable(this._map);
-
-  int get length => _map._length;
-  bool get isEmpty => _map._length == 0;
-
-  Iterator<E> get iterator {
-    return new LinkedHashMapKeyIterator<E>(_map, _map._modifications);
-  }
-
-  bool contains(Object element) {
-    return _map.containsKey(element);
-  }
-
-  void forEach(void f(E element)) {
-    LinkedHashMapCell cell = _map._first;
-    int modifications = _map._modifications;
-    while (cell != null) {
-      f(cell._key);
-      if (modifications != _map._modifications) {
-        throw new ConcurrentModificationError(_map);
-      }
-      cell = cell._next;
-    }
-  }
-}
-
-class LinkedHashMapKeyIterator<E> implements Iterator<E> {
-  final _map;
-  final int _modifications;
-  LinkedHashMapCell _cell;
-  E _current;
-
-  LinkedHashMapKeyIterator(this._map, this._modifications) {
-    _cell = _map._first;
-  }
-
-  E get current => _current;
-
-  bool moveNext() {
-    if (_modifications != _map._modifications) {
-      throw new ConcurrentModificationError(_map);
-    } else if (_cell == null) {
-      _current = null;
-      return false;
-    } else {
-      _current = _cell._key;
-      _cell = _cell._next;
-      return true;
-    }
-  }
-}
-
 @patch
 class HashSet<E> {
   @patch
   factory HashSet({ bool equals(E e1, E e2),
                     int hashCode(E e),
                     bool isValidKey(potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
           return new _HashSet<E>();
@@ skipping 850 matching lines @@
     } else if (_cell == null) {
       _current = null;
       return false;
     } else {
       _current = _cell._element;
       _cell = _cell._next;
       return true;
     }
   }
 }