EaglerForge/sources/main/java/com/google/common/collect/ImmutableMapEntry.java

73 lines
2.0 KiB
Java

/*
* Copyright (C) 2013 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 static com.google.common.collect.CollectPreconditions.checkEntryNotNull;
import javax.annotation.Nullable;
import com.google.common.annotations.GwtIncompatible;
/**
* Implementation of {@code Map.Entry} for {@link ImmutableMap} that adds extra
* methods to traverse hash buckets for the key and the value. This allows reuse
* in {@link RegularImmutableMap} and {@link RegularImmutableBiMap}, which don't
* have to recopy the entries created by their {@code Builder} implementations.
*
* @author Louis Wasserman
*/
@GwtIncompatible("unnecessary")
abstract class ImmutableMapEntry<K, V> extends ImmutableEntry<K, V> {
ImmutableMapEntry(K key, V value) {
super(key, value);
checkEntryNotNull(key, value);
}
ImmutableMapEntry(ImmutableMapEntry<K, V> contents) {
super(contents.getKey(), contents.getValue());
// null check would be redundant
}
@Nullable
abstract ImmutableMapEntry<K, V> getNextInKeyBucket();
@Nullable
abstract ImmutableMapEntry<K, V> getNextInValueBucket();
static final class TerminalEntry<K, V> extends ImmutableMapEntry<K, V> {
TerminalEntry(ImmutableMapEntry<K, V> contents) {
super(contents);
}
TerminalEntry(K key, V value) {
super(key, value);
}
@Override
@Nullable
ImmutableMapEntry<K, V> getNextInKeyBucket() {
return null;
}
@Override
@Nullable
ImmutableMapEntry<K, V> getNextInValueBucket() {
return null;
}
}
}