/
RegularImmutableSet.java
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/
RegularImmutableSet.java
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/*
* Copyright (C) 2007 The Guava Authors
*
* 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 com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.annotations.VisibleForTesting;
import java.util.Spliterator;
import java.util.Spliterators;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* Implementation of {@link ImmutableSet} with two or more elements.
*
* @author Kevin Bourrillion
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
@ElementTypesAreNonnullByDefault
final class RegularImmutableSet<E> extends ImmutableSet.CachingAsList<E> {
private static final Object[] EMPTY_ARRAY = new Object[0];
static final RegularImmutableSet<Object> EMPTY =
new RegularImmutableSet<>(EMPTY_ARRAY, 0, EMPTY_ARRAY, 0);
private final transient Object[] elements;
private final transient int hashCode;
// the same values as `elements` in hashed positions (plus nulls)
@VisibleForTesting final transient @Nullable Object[] table;
// 'and' with an int to get a valid table index.
private final transient int mask;
RegularImmutableSet(Object[] elements, int hashCode, @Nullable Object[] table, int mask) {
this.elements = elements;
this.hashCode = hashCode;
this.table = table;
this.mask = mask;
}
@Override
public boolean contains(@CheckForNull Object target) {
@Nullable Object[] table = this.table;
if (target == null || table.length == 0) {
return false;
}
for (int i = Hashing.smearedHash(target); ; i++) {
i &= mask;
Object candidate = table[i];
if (candidate == null) {
return false;
} else if (candidate.equals(target)) {
return true;
}
}
}
@Override
public int size() {
return elements.length;
}
// We're careful to put only E instances into the array in the mainline.
// (In the backport, we don't need this suppression, but we keep it to minimize diffs.)
@SuppressWarnings("unchecked")
@Override
public UnmodifiableIterator<E> iterator() {
return (UnmodifiableIterator<E>) Iterators.forArray(elements);
}
@Override
public Spliterator<E> spliterator() {
return Spliterators.spliterator(elements, SPLITERATOR_CHARACTERISTICS);
}
@Override
Object[] internalArray() {
return elements;
}
@Override
int internalArrayStart() {
return 0;
}
@Override
int internalArrayEnd() {
return elements.length;
}
@Override
int copyIntoArray(@Nullable Object[] dst, int offset) {
System.arraycopy(elements, 0, dst, offset, elements.length);
return offset + elements.length;
}
@Override
ImmutableList<E> createAsList() {
return (table.length == 0)
? ImmutableList.<E>of()
: new RegularImmutableAsList<E>(this, elements);
}
@Override
boolean isPartialView() {
return false;
}
@Override
public int hashCode() {
return hashCode;
}
@Override
boolean isHashCodeFast() {
return true;
}
// redeclare to help optimizers with b/310253115
@SuppressWarnings("RedundantOverride")
@Override
@J2ktIncompatible // serialization
@GwtIncompatible // serialization
Object writeReplace() {
return super.writeReplace();
}
}