2 * (C) Copyright 2016 Pantheon Technologies, s.r.o. and others.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.opendaylight.yangtools.triemap;
18 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
20 abstract class MainNode<K, V> extends BasicNode {
21 static final int NO_SIZE = -1;
23 @SuppressWarnings("rawtypes")
24 private static final AtomicReferenceFieldUpdater<MainNode, MainNode> PREV_UPDATER =
25 AtomicReferenceFieldUpdater.newUpdater(MainNode.class, MainNode.class, "prev");
27 private volatile MainNode<K, V> prev;
33 MainNode(final MainNode<K, V> prev) {
38 * Return the number of entries in this node, or {@link #NO_SIZE} if it is not known.
40 abstract int trySize();
43 * Return the number of entries in this node, traversing it if need be. This method should be invoked only
44 * on immutable snapshots.
46 * @param ct TrieMap reference
47 * @return The actual number of entries.
49 abstract int size(ImmutableTrieMap<?, ?> ct);
51 final boolean casPrev(final MainNode<K, V> oldval, final MainNode<K, V> nval) {
52 return PREV_UPDATER.compareAndSet(this, oldval, nval);
55 final void writePrev(final MainNode<K, V> nval) {
59 final MainNode<K, V> readPrev() {