| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.lucene.util.automaton; |
| |
| import java.util.Arrays; |
| import org.apache.lucene.util.hppc.BitMixer; |
| import org.apache.lucene.util.hppc.IntIntHashMap; |
| |
| /** |
| * A thin wrapper of {@link IntIntHashMap} Maps from state in integer representation to its |
| * reference count Whenever the count of a state is 0, that state will be removed from the set |
| */ |
| final class StateSet extends IntSet { |
| |
| private final IntIntHashMap inner; |
| private long hashCode; |
| private boolean hashUpdated = true; |
| private boolean arrayUpdated = true; |
| private int[] arrayCache = new int[0]; |
| |
| StateSet(int capacity) { |
| inner = new IntIntHashMap(capacity); |
| } |
| |
| /** |
| * Add the state into this set, if it is already there, increase its reference count by 1 |
| * |
| * @param state an integer representing this state |
| */ |
| void incr(int state) { |
| if (inner.addTo(state, 1) == 1) { |
| keyChanged(); |
| } |
| } |
| |
| /** |
| * Decrease the reference count of the state, if the count down to 0, remove the state from this |
| * set |
| * |
| * @param state an integer representing this state |
| */ |
| void decr(int state) { |
| assert inner.containsKey(state); |
| int keyIndex = inner.indexOf(state); |
| int count = inner.indexGet(keyIndex) - 1; |
| if (count == 0) { |
| inner.indexRemove(keyIndex); |
| keyChanged(); |
| } else { |
| inner.indexReplace(keyIndex, count); |
| } |
| } |
| |
| /** |
| * Create a snapshot of this int set associated with a given state. The snapshot will not retain |
| * any frequency information about the elements of this set, only existence. |
| * |
| * @param state the state to associate with the frozen set. |
| * @return A new FrozenIntSet with the same values as this set. |
| */ |
| FrozenIntSet freeze(int state) { |
| return new FrozenIntSet(getArray(), longHashCode(), state); |
| } |
| |
| private void keyChanged() { |
| hashUpdated = false; |
| arrayUpdated = false; |
| } |
| |
| @Override |
| int[] getArray() { |
| if (arrayUpdated) { |
| return arrayCache; |
| } |
| arrayCache = new int[inner.size()]; |
| int i = 0; |
| for (IntIntHashMap.IntCursor cursor : inner.keys()) { |
| arrayCache[i++] = cursor.value; |
| } |
| // we need to sort this array since "equals" method depend on this |
| Arrays.sort(arrayCache); |
| arrayUpdated = true; |
| return arrayCache; |
| } |
| |
| @Override |
| int size() { |
| return inner.size(); |
| } |
| |
| @Override |
| long longHashCode() { |
| if (hashUpdated) { |
| return hashCode; |
| } |
| hashCode = inner.size(); |
| for (IntIntHashMap.IntCursor cursor : inner.keys()) { |
| hashCode += BitMixer.mix(cursor.value); |
| } |
| hashUpdated = true; |
| return hashCode; |
| } |
| } |