modules/core/src/main/java/org/apache/ignite/internal/managers/discovery/ConsistentIdMapper.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.ignite.internal.managers.discovery;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.UUID;
import org.apache.ignite.internal.processors.affinity.AffinityTopologyVersion;
import org.apache.ignite.internal.processors.cluster.BaselineTopology;
import org.apache.ignite.internal.util.typedef.internal.U;
import org.jetbrains.annotations.Nullable;

/**
 * Class is needed for map UUID to consistent id and vice versa.
 */
public class ConsistentIdMapper {
    /** Discovery manager. */
    private final GridDiscoveryManager discoveryMgr;

    /**
     * Create an instance of mapper.
     *
     * @param discoveryMgr Discovery manager.
     */
    public ConsistentIdMapper(GridDiscoveryManager discoveryMgr) {
        this.discoveryMgr = discoveryMgr;
    }

    /**
     * Maps UUID to compact ID for given baseline topology.
     *
     * @param topVer Topology version.
     * @param nodeId UUID of node.
     * @return Compact ID of node for given baseline topology.
     */
    public short mapToCompactId(AffinityTopologyVersion topVer, UUID nodeId) {
        Map<UUID, Short> m = discoveryMgr.consistentId(topVer);

        if (m == null)
            throw new IllegalStateException("Unable to find consistent id map [topVer" + topVer + ']');

        Short constId = m.get(nodeId);

        if (constId == null)
            throw new IllegalStateException("Unable to find consistentId by UUID [nodeId=" + nodeId + ", topVer=" + topVer + ']');

        return constId;
    }

    /**
     * Maps UUID to compact ID for given baseline topology.
     *
     * @param topVer Topology version.
     * @param nodeConstId UUID of node.
     * @return Compact ID of node for given baseline topology.
     */
    public UUID mapToUuid(AffinityTopologyVersion topVer, short nodeConstId) {
        Map<Short, UUID> map = discoveryMgr.nodeIdMap(topVer);

        if (map == null)
            return null;

        UUID constId = map.get(nodeConstId);

        if (constId == null)
            throw new IllegalStateException("Unable to find UUID by constId [nodeId=" + nodeConstId + ", topVer=" + topVer + ']');

        return constId;
    }

    /**
     * Map primary -> backup node compact ID accordingly to baseline topology..
     *
     * @param txNodes Primary -> backup UUID nodes.
     * @return Primary -> backup compact ID nodes.
     */
    public Map<Short, Collection<Short>> mapToCompactIds(
        AffinityTopologyVersion topVer,
        @Nullable Map<UUID, Collection<UUID>> txNodes,
        BaselineTopology baselineTop
    ) {
        if (txNodes == null)
            return null;

        Map<Object, Short> constIdMap = baselineTop.consistentIdMapping();

        Map<UUID, Short> m = discoveryMgr.consistentId(topVer);

        int bltNodes = m.size();

        Map<Short, Collection<Short>> consistentMap = U.newHashMap(txNodes.size());

        int nodeCnt = 0;

        for (Map.Entry<UUID, Collection<UUID>> e : txNodes.entrySet()) {
            UUID node = e.getKey();

            Collection<UUID> backupNodes = e.getValue();

            Collection<Short> backups = new ArrayList<>(backupNodes.size());

            for (UUID backup : backupNodes) {
                if (m.containsKey(backup))
                    nodeCnt++;

                backups.add(mapToCompactId(topVer, backup));
            }

            // Optimization for short store full nodes set.
            if (backups.size() == nodeCnt && nodeCnt == (bltNodes - 1))
                backups = Collections.singletonList(Short.MAX_VALUE);

            consistentMap.put(mapToCompactId(topVer, node), backups);
        }

        return consistentMap;
    }
}