org.eclipse.milo.opcua.sdk.client.NodeCache Maven / Gradle / Ivy
/*
* Copyright (c) 2019 the Eclipse Milo Authors
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which is available at https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*/
package org.eclipse.milo.opcua.sdk.client;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;
import javax.annotation.Nullable;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.eclipse.milo.opcua.sdk.client.nodes.UaNode;
import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
public class NodeCache {
private final Cache cachedNodes;
private final ConcurrentMap canonicalNodes;
public NodeCache() {
this(b -> {});
}
public NodeCache(Consumer> consumer) {
CacheBuilder builder = CacheBuilder.newBuilder()
.expireAfterWrite(2, TimeUnit.MINUTES)
.maximumSize(16384)
.recordStats();
consumer.accept(builder);
this.cachedNodes = builder.build();
this.canonicalNodes = new ConcurrentHashMap<>();
}
/**
* Canonicalize {@code node} in the NodeCache and return it.
*
* If a canonical {@link UaNode} by the same {@link NodeId} already exists that instance is
* returned.
*
* @param node the {@link UaNode} to canonicalize.
* @return the canonical node instance.
*/
public UaNode canonicalize(UaNode node) {
NodeId nodeId = node.getNodeId();
UaNode prev = canonicalNodes.putIfAbsent(nodeId, node);
return prev != null ? prev : node;
}
@Nullable
public UaNode getIfPresent(NodeId nodeId) {
return canonicalNodes.getOrDefault(
nodeId,
cachedNodes.getIfPresent(nodeId)
);
}
public void put(NodeId nodeId, UaNode node) {
cachedNodes.put(nodeId, node);
}
public void invalidate(NodeId nodeId) {
canonicalNodes.remove(nodeId);
cachedNodes.invalidate(nodeId);
}
}