com.google.common.collect.JdkBackedImmutableMap Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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/*
* Copyright (C) 2018 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.base.Preconditions.checkNotNull;
import static com.google.common.collect.RegularImmutableMap.makeImmutable;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.HashMap;
import java.util.Map;
import java.util.function.BiConsumer;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* Implementation of ImmutableMap backed by a JDK HashMap, which has smartness protecting against
* hash flooding.
*/
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableMap extends ImmutableMap {
/**
* Creates an {@code ImmutableMap} backed by a JDK HashMap. Used when probable hash flooding is
* detected. This implementation may replace the entries in entryArray with its own entry objects
* (though they will have the same key/value contents), and will take ownership of entryArray.
*/
static ImmutableMap create(
int n, @Nullable Entry[] entryArray, boolean throwIfDuplicateKeys) {
Map delegateMap = Maps.newHashMapWithExpectedSize(n);
// If duplicates are allowed, this map will track the last value for each duplicated key.
// A second pass will retain only the first entry for that key, but with this last value. The
// value will then be replaced by null, signaling that later entries with the same key should
// be deleted.
Map duplicates = null;
int dupCount = 0;
for (int i = 0; i < n; i++) {
// requireNonNull is safe because the first `n` elements have been filled in.
entryArray[i] = makeImmutable(requireNonNull(entryArray[i]));
K key = entryArray[i].getKey();
V value = entryArray[i].getValue();
V oldValue = delegateMap.put(key, value);
if (oldValue != null) {
if (throwIfDuplicateKeys) {
throw conflictException("key", entryArray[i], entryArray[i].getKey() + "=" + oldValue);
}
if (duplicates == null) {
duplicates = new HashMap<>();
}
duplicates.put(key, value);
dupCount++;
}
}
if (duplicates != null) {
@SuppressWarnings({"rawtypes", "unchecked"})
Entry[] newEntryArray = new Entry[n - dupCount];
for (int inI = 0, outI = 0; inI < n; inI++) {
Entry entry = requireNonNull(entryArray[inI]);
K key = entry.getKey();
if (duplicates.containsKey(key)) {
V value = duplicates.get(key);
if (value == null) {
continue; // delete this duplicate
}
entry = new ImmutableMapEntry<>(key, value);
duplicates.put(key, null);
}
newEntryArray[outI++] = entry;
}
entryArray = newEntryArray;
}
return new JdkBackedImmutableMap<>(delegateMap, ImmutableList.asImmutableList(entryArray, n));
}
private final transient Map delegateMap;
private final transient ImmutableList> entries;
JdkBackedImmutableMap(Map delegateMap, ImmutableList> entries) {
this.delegateMap = delegateMap;
this.entries = entries;
}
@Override
public int size() {
return entries.size();
}
@Override
@CheckForNull
public V get(@CheckForNull Object key) {
return delegateMap.get(key);
}
@Override
ImmutableSet> createEntrySet() {
return new ImmutableMapEntrySet.RegularEntrySet<>(this, entries);
}
@Override
public void forEach(BiConsumer super K, ? super V> action) {
checkNotNull(action);
entries.forEach(e -> action.accept(e.getKey(), e.getValue()));
}
@Override
ImmutableSet createKeySet() {
return new ImmutableMapKeySet<>(this);
}
@Override
ImmutableCollection createValues() {
return new ImmutableMapValues<>(this);
}
@Override
boolean isPartialView() {
return false;
}
// redeclare to help optimizers with b/310253115
@SuppressWarnings("RedundantOverride")
@Override
@J2ktIncompatible // serialization
@GwtIncompatible // serialization
Object writeReplace() {
return super.writeReplace();
}
}