org.fakereplace.com.google.common.collect.RegularImmutableSet Maven / Gradle / Ivy

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/*
 * Copyright (C) 2007 Google Inc.
 *
 * Licensed 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.fakereplace.com.google.common.collect;

import org.fakereplace.com.google.common.annotations.GwtCompatible;
import org.fakereplace.com.google.common.annotations.VisibleForTesting;

/**
 * Implementation of {@link ImmutableSet} with two or more elements.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(serializable = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableSet extends ImmutableSet.ArrayImmutableSet {
    // the same elements in hashed positions (plus nulls)
    @VisibleForTesting
    final transient Object[] table;
    // 'and' with an int to get a valid table index.
    private final transient int mask;
    private final transient int hashCode;

    RegularImmutableSet(
            Object[] elements, int hashCode, Object[] table, int mask) {
        super(elements);
        this.table = table;
        this.mask = mask;
        this.hashCode = hashCode;
    }

    @Override
    public boolean contains(Object target) {
        if (target == null) {
            return false;
        }
        for (int i = Hashing.smear(target.hashCode()); true; i++) {
            Object candidate = table[i & mask];
            if (candidate == null) {
                return false;
            }
            if (candidate.equals(target)) {
                return true;
            }
        }
    }

    @Override
    public int hashCode() {
        return hashCode;
    }

    @Override
    boolean isHashCodeFast() {
        return true;
    }
}