2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.util;
12 import org.slf4j.Logger;
13 import org.slf4j.LoggerFactory;
15 import com.google.common.base.Preconditions;
16 import com.google.common.collect.ForwardingMap;
17 import com.romix.scala.collection.concurrent.TrieMap;
20 * A read-only facade in front of a TrieMap. This is what we give out from
21 * MapAdaptor.optimize(). The idea is that we want our read-only users to
22 * share a single snapshot. That snapshot is instantiated lazily either on
23 * first access. Since we never leak the TrieMap and track its size as it
24 * changes, we can cache it for future reference.
26 final class ReadOnlyTrieMap<K, V> extends ForwardingMap<K, V> {
27 private static final Logger LOG = LoggerFactory.getLogger(ReadOnlyTrieMap.class);
28 private final TrieMap<K, V> readWrite;
29 private final int size;
30 private TrieMap<K, V> readOnly;
32 ReadOnlyTrieMap(final TrieMap<K, V> map, final int size) {
34 this.readWrite = Preconditions.checkNotNull(map);
38 Map<K, V> toReadWrite() {
39 final Map<K, V> ret = new ReadWriteTrieMap<>(readWrite.snapshot(), size);
40 LOG.trace("Converted read-only TrieMap {} to read-write {}", this, ret);
45 protected Map<K, V> delegate() {
46 if (readOnly == null) {
48 if (readOnly == null) {
49 readOnly = readWrite.readOnlySnapshot();