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/*
* Copyright (C) 2012 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.base.Preconditions.checkPositionIndex;
import static java.util.Collections.emptyList;
import static java.util.Collections.emptySet;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.j2objc.annotations.WeakOuter;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.checker.signedness.qual.UnknownSignedness;
/**
* Implementation of {@link Multimaps#filterKeys(Multimap, Predicate)}.
*
* @author Louis Wasserman
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
class FilteredKeyMultimap
extends AbstractMultimap implements FilteredMultimap {
final Multimap unfiltered;
final Predicate keyPredicate;
FilteredKeyMultimap(Multimap unfiltered, Predicate keyPredicate) {
this.unfiltered = checkNotNull(unfiltered);
this.keyPredicate = checkNotNull(keyPredicate);
}
@Override
public Multimap unfiltered() {
return unfiltered;
}
@Override
public Predicate> entryPredicate() {
return Maps.keyPredicateOnEntries(keyPredicate);
}
@Override
public int size() {
int size = 0;
for (Collection collection : asMap().values()) {
size += collection.size();
}
return size;
}
@Override
public boolean containsKey(@CheckForNull @UnknownSignedness Object key) {
if (unfiltered.containsKey(key)) {
@SuppressWarnings("unchecked") // k is equal to a K, if not one itself
K k = (K) key;
return keyPredicate.apply(k);
}
return false;
}
@Override
public Collection removeAll(@CheckForNull Object key) {
return containsKey(key) ? unfiltered.removeAll(key) : unmodifiableEmptyCollection();
}
Collection unmodifiableEmptyCollection() {
if (unfiltered instanceof SetMultimap) {
return emptySet();
} else {
return emptyList();
}
}
@Override
public void clear() {
keySet().clear();
}
@Override
Set createKeySet() {
return Sets.filter(unfiltered.keySet(), keyPredicate);
}
@Override
public Collection get(@ParametricNullness K key) {
if (keyPredicate.apply(key)) {
return unfiltered.get(key);
} else if (unfiltered instanceof SetMultimap) {
return new AddRejectingSet<>(key);
} else {
return new AddRejectingList<>(key);
}
}
static class AddRejectingSet
extends ForwardingSet {
@ParametricNullness final K key;
AddRejectingSet(@ParametricNullness K key) {
this.key = key;
}
@Override
public boolean add(@ParametricNullness V element) {
throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
}
@Override
public boolean addAll(Collection collection) {
checkNotNull(collection);
throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
}
@Override
protected Set delegate() {
return Collections.emptySet();
}
}
static class AddRejectingList
extends ForwardingList {
@ParametricNullness final K key;
AddRejectingList(@ParametricNullness K key) {
this.key = key;
}
@Override
public boolean add(@ParametricNullness V v) {
add(0, v);
return true;
}
@Override
public void add(int index, @ParametricNullness V element) {
checkPositionIndex(index, 0);
throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
}
@Override
public boolean addAll(Collection collection) {
addAll(0, collection);
return true;
}
@CanIgnoreReturnValue
@Override
public boolean addAll(int index, Collection elements) {
checkNotNull(elements);
checkPositionIndex(index, 0);
throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
}
@Override
protected List delegate() {
return Collections.emptyList();
}
}
@Override
Iterator> entryIterator() {
throw new AssertionError("should never be called");
}
@Override
Collection> createEntries() {
return new Entries();
}
@WeakOuter
class Entries extends ForwardingCollection> {
@Override
protected Collection> delegate() {
return Collections2.filter(unfiltered.entries(), entryPredicate());
}
@Override
@SuppressWarnings("unchecked")
public boolean remove(@CheckForNull @UnknownSignedness Object o) {
if (o instanceof Entry) {
Entry entry = (Entry) o;
if (unfiltered.containsKey(entry.getKey())
// if this holds, then we know entry.getKey() is a K
&& keyPredicate.apply((K) entry.getKey())) {
return unfiltered.remove(entry.getKey(), entry.getValue());
}
}
return false;
}
}
@Override
Collection createValues() {
return new FilteredMultimapValues<>(this);
}
@Override
Map> createAsMap() {
return Maps.filterKeys(unfiltered.asMap(), keyPredicate);
}
@Override
Multiset createKeys() {
return Multisets.filter(unfiltered.keys(), keyPredicate);
}
}