| Index: corelib/src/implementation/hash_map_set.dart
|
| diff --git a/corelib/src/implementation/hash_map_set.dart b/corelib/src/implementation/hash_map_set.dart
|
| deleted file mode 100644
|
| index c3d45790e5f4af5bb17c6c62442fd8e765b925c0..0000000000000000000000000000000000000000
|
| --- a/corelib/src/implementation/hash_map_set.dart
|
| +++ /dev/null
|
| @@ -1,454 +0,0 @@
|
| -// Copyright (c) 2012, 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.
|
| -
|
| -// Hash map implementation with open addressing and quadratic probing.
|
| -class HashMapImplementation<K extends Hashable, V> implements HashMap<K, V> {
|
| -
|
| - // The [_keys] list contains the keys inserted in the map.
|
| - // The [_keys] list must be a raw list because it
|
| - // will contain both elements of type K, and the [_DELETED_KEY] of type
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| - // [_DeletedKeySentinel].
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| - // The alternative of declaring the [_keys] list as of type Object
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| - // does not work, because the HashSetIterator constructor would fail:
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| - // HashSetIterator(HashSet<E> set)
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| - // : _nextValidIndex = -1,
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| - // _entries = set_._backingMap._keys {
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| - // _advance();
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| - // }
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| - // With K being type int, for example, it would fail because
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| - // List<Object> is not assignable to type List<int> of entries.
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| - List _keys;
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| -
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| - // The values inserted in the map. For a filled entry index in this
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| - // list, there is always the corresponding key in the [keys_] list
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| - // at the same entry index.
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| - List<V> _values;
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| -
|
| - // The load limit is the number of entries we allow until we double
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| - // the size of the lists.
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| - int _loadLimit;
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| -
|
| - // The current number of entries in the map. Will never be greater
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| - // than [_loadLimit].
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| - int _numberOfEntries;
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| -
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| - // The current number of deleted entries in the map.
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| - int _numberOfDeleted;
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| -
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| - // The sentinel when a key is deleted from the map.
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| - static final _DeletedKeySentinel _DELETED_KEY = const _DeletedKeySentinel();
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| -
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| - // The initial capacity of a hash map.
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| - static final int _INITIAL_CAPACITY = 8; // must be power of 2
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| -
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| - HashMapImplementation() {
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| - _numberOfEntries = 0;
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| - _numberOfDeleted = 0;
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| - _loadLimit = _computeLoadLimit(_INITIAL_CAPACITY);
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| - _keys = new List(_INITIAL_CAPACITY);
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| - _values = new List<V>(_INITIAL_CAPACITY);
|
| - }
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| -
|
| - factory HashMapImplementation.from(Map<K, V> other) {
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| - Map<K, V> result = new HashMapImplementation<K, V>();
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| - other.forEach((K key, V value) { result[key] = value; });
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| - return result;
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| - }
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| -
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| - static int _computeLoadLimit(int capacity) {
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| - return (capacity * 3) ~/ 4;
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| - }
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| -
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| - static int _firstProbe(int hashCode, int length) {
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| - return hashCode & (length - 1);
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| - }
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| -
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| - static int _nextProbe(int currentProbe, int numberOfProbes, int length) {
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| - return (currentProbe + numberOfProbes) & (length - 1);
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| - }
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| -
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| - int _probeForAdding(K key) {
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| - int hash = _firstProbe(key.hashCode(), _keys.length);
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| - int numberOfProbes = 1;
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| - int initialHash = hash;
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| - // insertionIndex points to a slot where a key was deleted.
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| - int insertionIndex = -1;
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| - while (true) {
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| - // [existingKey] can be either of type [K] or [_DeletedKeySentinel].
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| - Object existingKey = _keys[hash];
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| - if (existingKey === null) {
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| - // We are sure the key is not already in the set.
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| - // If the current slot is empty and we didn't find any
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| - // insertion slot before, return this slot.
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| - if (insertionIndex < 0) return hash;
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| - // If we did find an insertion slot before, return it.
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| - return insertionIndex;
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| - } else if (existingKey == key) {
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| - // The key is already in the map. Return its slot.
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| - return hash;
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| - } else if ((insertionIndex < 0) && (_DELETED_KEY === existingKey)) {
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| - // The slot contains a deleted element. Because previous calls to this
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| - // method may not have had this slot deleted, we must continue iterate
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| - // to find if there is a slot with the given key.
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| - insertionIndex = hash;
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| - }
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| -
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| - // We did not find an insertion slot. Look at the next one.
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| - hash = _nextProbe(hash, numberOfProbes++, _keys.length);
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| - // _ensureCapacity has guaranteed the following cannot happen.
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| - // assert(hash != initialHash);
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| - }
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| - }
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| -
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| - int _probeForLookup(K key) {
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| - int hash = _firstProbe(key.hashCode(), _keys.length);
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| - int numberOfProbes = 1;
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| - int initialHash = hash;
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| - while (true) {
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| - // [existingKey] can be either of type [K] or [_DeletedKeySentinel].
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| - Object existingKey = _keys[hash];
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| - // If the slot does not contain anything (in particular, it does not
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| - // contain a deleted key), we know the key is not in the map.
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| - if (existingKey === null) return -1;
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| - // The key is in the map, return its index.
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| - if (existingKey == key) return hash;
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| - // Go to the next probe.
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| - hash = _nextProbe(hash, numberOfProbes++, _keys.length);
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| - // _ensureCapacity has guaranteed the following cannot happen.
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| - // assert(hash != initialHash);
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| - }
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| - }
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| -
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| - void _ensureCapacity() {
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| - int newNumberOfEntries = _numberOfEntries + 1;
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| - // Test if adding an element will reach the load limit.
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| - if (newNumberOfEntries >= _loadLimit) {
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| - _grow(_keys.length * 2);
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| - return;
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| - }
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| -
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| - // Make sure that we don't have poor performance when a map
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| - // contains lots of deleted entries: we _grow if
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| - // there are more deleted entried than free entries.
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| - int capacity = _keys.length;
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| - int numberOfFreeOrDeleted = capacity - newNumberOfEntries;
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| - int numberOfFree = numberOfFreeOrDeleted - _numberOfDeleted;
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| - // assert(numberOfFree > 0);
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| - if (_numberOfDeleted > numberOfFree) {
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| - _grow(_keys.length);
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| - }
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| - }
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| -
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| - static bool _isPowerOfTwo(int x) {
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| - return ((x & (x - 1)) == 0);
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| - }
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| -
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| - void _grow(int newCapacity) {
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| - assert(_isPowerOfTwo(newCapacity));
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| - int capacity = _keys.length;
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| - _loadLimit = _computeLoadLimit(newCapacity);
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| - List oldKeys = _keys;
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| - List<V> oldValues = _values;
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| - _keys = new List(newCapacity);
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| - _values = new List<V>(newCapacity);
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| - for (int i = 0; i < capacity; i++) {
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| - // [key] can be either of type [K] or [_DeletedKeySentinel].
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| - Object key = oldKeys[i];
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| - // If there is no key, we don't need to deal with the current slot.
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| - if (key === null || key === _DELETED_KEY) {
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| - continue;
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| - }
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| - V value = oldValues[i];
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| - // Insert the {key, value} pair in their new slot.
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| - int newIndex = _probeForAdding(key);
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| - _keys[newIndex] = key;
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| - _values[newIndex] = value;
|
| - }
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| - _numberOfDeleted = 0;
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| - }
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| -
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| - void clear() {
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| - _numberOfEntries = 0;
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| - _numberOfDeleted = 0;
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| - int length = _keys.length;
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| - for (int i = 0; i < length; i++) {
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| - _keys[i] = null;
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| - _values[i] = null;
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| - }
|
| - }
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| -
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| - void operator []=(K key, V value) {
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| - _ensureCapacity();
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| - int index = _probeForAdding(key);
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| - if ((_keys[index] === null) || (_keys[index] === _DELETED_KEY)) {
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| - _numberOfEntries++;
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| - }
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| - _keys[index] = key;
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| - _values[index] = value;
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| - }
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| -
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| - V operator [](K key) {
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| - int index = _probeForLookup(key);
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| - if (index < 0) return null;
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| - return _values[index];
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| - }
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| -
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| - V putIfAbsent(K key, V ifAbsent()) {
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| - int index = _probeForLookup(key);
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| - if (index >=0) return _values[index];
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| -
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| - V value = ifAbsent();
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| - this[key] = value;
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| - return value;
|
| - }
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| -
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| - V remove(K key) {
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| - int index = _probeForLookup(key);
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| - if (index >= 0) {
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| - _numberOfEntries--;
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| - V value = _values[index];
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| - _values[index] = null;
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| - // Set the key to the sentinel to not break the probing chain.
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| - _keys[index] = _DELETED_KEY;
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| - _numberOfDeleted++;
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| - return value;
|
| - }
|
| - return null;
|
| - }
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| -
|
| - bool isEmpty() {
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| - return _numberOfEntries == 0;
|
| - }
|
| -
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| - int get length() {
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| - return _numberOfEntries;
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| - }
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| -
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| - void forEach(void f(K key, V value)) {
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| - int length = _keys.length;
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| - for (int i = 0; i < length; i++) {
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| - var key = _keys[i];
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| - if ((key !== null) && (key !== _DELETED_KEY)) {
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| - f(key, _values[i]);
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| - }
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| - }
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| - }
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| -
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| -
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| - Collection<K> getKeys() {
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| - List<K> list = new List<K>(length);
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| - int i = 0;
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| - forEach(void _(K key, V value) {
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| - list[i++] = key;
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| - });
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| - return list;
|
| - }
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| -
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| - Collection<V> getValues() {
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| - List<V> list = new List<V>(length);
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| - int i = 0;
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| - forEach(void _(K key, V value) {
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| - list[i++] = value;
|
| - });
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| - return list;
|
| - }
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| -
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| - bool containsKey(K key) {
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| - return (_probeForLookup(key) != -1);
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| - }
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| -
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| - bool containsValue(V value) {
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| - int length = _values.length;
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| - for (int i = 0; i < length; i++) {
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| - var key = _keys[i];
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| - if ((key !== null) && (key !== _DELETED_KEY)) {
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| - if (_values[i] == value) return true;
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| - }
|
| - }
|
| - return false;
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| - }
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| -
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| - String toString() {
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| - return Maps.mapToString(this);
|
| - }
|
| -}
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| -
|
| -class HashSetImplementation<E extends Hashable> implements HashSet<E> {
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| -
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| - HashSetImplementation() {
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| - _backingMap = new HashMapImplementation<E, E>();
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| - }
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| -
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| - factory HashSetImplementation.from(Iterable<E> other) {
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| - Set<E> set = new HashSetImplementation<E>();
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| - for (final e in other) {
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| - set.add(e);
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| - }
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| - return set;
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| - }
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| -
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| - void clear() {
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| - _backingMap.clear();
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| - }
|
| -
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| - void add(E value) {
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| - _backingMap[value] = value;
|
| - }
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| -
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| - bool contains(E value) {
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| - return _backingMap.containsKey(value);
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| - }
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| -
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| - bool remove(E value) {
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| - if (!_backingMap.containsKey(value)) return false;
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| - _backingMap.remove(value);
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| - return true;
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| - }
|
| -
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| - void addAll(Collection<E> collection) {
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| - collection.forEach(void _(E value) {
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| - add(value);
|
| - });
|
| - }
|
| -
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| - Set<E> intersection(Collection<E> collection) {
|
| - Set<E> result = new Set<E>();
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| - collection.forEach(void _(E value) {
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| - if (contains(value)) result.add(value);
|
| - });
|
| - return result;
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| - }
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| -
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| - bool isSubsetOf(Collection<E> other) {
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| - return new Set<E>.from(other).containsAll(this);
|
| - }
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| -
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| - void removeAll(Collection<E> collection) {
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| - collection.forEach(void _(E value) {
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| - remove(value);
|
| - });
|
| - }
|
| -
|
| - bool containsAll(Collection<E> collection) {
|
| - return collection.every(bool _(E value) {
|
| - return contains(value);
|
| - });
|
| - }
|
| -
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| - void forEach(void f(E element)) {
|
| - _backingMap.forEach(void _(E key, E value) {
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| - f(key);
|
| - });
|
| - }
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| -
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| - Set map(f(E element)) {
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| - Set result = new Set();
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| - _backingMap.forEach(void _(E key, E value) {
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| - result.add(f(key));
|
| - });
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| - return result;
|
| - }
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| -
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| - Dynamic reduce(Dynamic initialValue,
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| - Dynamic combine(Dynamic previousValue, E element)) {
|
| - return Collections.reduce(this, initialValue, combine);
|
| - }
|
| -
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| - Set<E> filter(bool f(E element)) {
|
| - Set<E> result = new Set<E>();
|
| - _backingMap.forEach(void _(E key, E value) {
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| - if (f(key)) result.add(key);
|
| - });
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| - return result;
|
| - }
|
| -
|
| - bool every(bool f(E element)) {
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| - Collection<E> keys = _backingMap.getKeys();
|
| - return keys.every(f);
|
| - }
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| -
|
| - bool some(bool f(E element)) {
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| - Collection<E> keys = _backingMap.getKeys();
|
| - return keys.some(f);
|
| - }
|
| -
|
| - bool isEmpty() {
|
| - return _backingMap.isEmpty();
|
| - }
|
| -
|
| - int get length() {
|
| - return _backingMap.length;
|
| - }
|
| -
|
| - Iterator<E> iterator() {
|
| - return new HashSetIterator<E>(this);
|
| - }
|
| -
|
| - String toString() {
|
| - return Collections.collectionToString(this);
|
| - }
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| -
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| - // The map backing this set. The associations in this map are all
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| - // of the form element -> element. If a value is not in the map,
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| - // then it is not in the set.
|
| - HashMapImplementation<E, E> _backingMap;
|
| -}
|
| -
|
| -class HashSetIterator<E> implements Iterator<E> {
|
| -
|
| - // TODO(4504458): Replace set_ with set.
|
| - HashSetIterator(HashSetImplementation<E> set_)
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| - : _nextValidIndex = -1,
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| - _entries = set_._backingMap._keys {
|
| - _advance();
|
| - }
|
| -
|
| - bool hasNext() {
|
| - if (_nextValidIndex >= _entries.length) return false;
|
| - if (_entries[_nextValidIndex] === HashMapImplementation._DELETED_KEY) {
|
| - // This happens in case the set was modified in the meantime.
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| - // A modification on the set may make this iterator misbehave,
|
| - // but we should never return the sentinel.
|
| - _advance();
|
| - }
|
| - return _nextValidIndex < _entries.length;
|
| - }
|
| -
|
| - E next() {
|
| - if (!hasNext()) {
|
| - throw const NoMoreElementsException();
|
| - }
|
| - E res = _entries[_nextValidIndex];
|
| - _advance();
|
| - return res;
|
| - }
|
| -
|
| - void _advance() {
|
| - int length = _entries.length;
|
| - var entry;
|
| - final deletedKey = HashMapImplementation._DELETED_KEY;
|
| - do {
|
| - if (++_nextValidIndex >= length) break;
|
| - entry = _entries[_nextValidIndex];
|
| - } while ((entry === null) || (entry === deletedKey));
|
| - }
|
| -
|
| - // The entries in the set. May contain null or the sentinel value.
|
| - List<E> _entries;
|
| -
|
| - // The next valid index in [_entries] or the length of [entries_].
|
| - // If it is the length of [_entries], calling [hasNext] on the
|
| - // iterator will return false.
|
| - int _nextValidIndex;
|
| -}
|
| -
|
| -/**
|
| - * A singleton sentinel used to represent when a key is deleted from the map.
|
| - * We can't use [: const Object() :] as a sentinel because it would end up
|
| - * canonicalized and then we cannot distinguish the deleted key from the
|
| - * canonicalized [: Object() :].
|
| - */
|
| -class _DeletedKeySentinel {
|
| - const _DeletedKeySentinel();
|
| -}
|
|
|