1 /* 2 * Copyright (C) 2007 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.collect; 18 19 import com.google.common.annotations.GwtCompatible; 20 import com.google.common.annotations.VisibleForTesting; 21 import com.google.common.collect.ImmutableSet.ArrayImmutableSet; 22 23 /** 24 * Implementation of {@link ImmutableSet} with two or more elements. 25 * 26 * @author Kevin Bourrillion 27 */ 28 @GwtCompatible(serializable = true, emulated = true) 29 @SuppressWarnings("serial") // uses writeReplace(), not default serialization 30 final class RegularImmutableSet<E> extends ArrayImmutableSet<E> { 31 // the same elements in hashed positions (plus nulls) 32 @VisibleForTesting final transient Object[] table; 33 // 'and' with an int to get a valid table index. 34 private final transient int mask; 35 private final transient int hashCode; 36 37 RegularImmutableSet( 38 Object[] elements, int hashCode, Object[] table, int mask) { 39 super(elements); 40 this.table = table; 41 this.mask = mask; 42 this.hashCode = hashCode; 43 } 44 45 @Override public boolean contains(Object target) { 46 if (target == null) { 47 return false; 48 } 49 for (int i = Hashing.smear(target.hashCode()); true; i++) { 50 Object candidate = table[i & mask]; 51 if (candidate == null) { 52 return false; 53 } 54 if (candidate.equals(target)) { 55 return true; 56 } 57 } 58 } 59 60 @Override public int hashCode() { 61 return hashCode; 62 } 63 64 @Override boolean isHashCodeFast() { 65 return true; 66 } 67 } 68
