org.neo4j.lock.LockTracer Maven / Gradle / Ivy

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/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [https://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.lock;

@FunctionalInterface
public interface LockTracer {
    LockWaitEvent waitForLock(LockType lockType, ResourceType resourceType, long transactionId, long... resourceIds);

    default LockTracer combine(LockTracer tracer) {
        if (tracer == NONE) {
            return this;
        }
        if (this == NONE) {
            return tracer;
        }
        return new CombinedTracer(this, tracer);
    }

    LockTracer NONE = new LockTracer() {
        @Override
        public LockWaitEvent waitForLock(
                LockType lockType, ResourceType resourceType, long transactionId, long... resourceIds) {
            return LockWaitEvent.NONE;
        }

        @Override
        public LockTracer combine(LockTracer tracer) {
            return tracer;
        }

        @Override
        public String toString() {
            return "LockTracer.NONE";
        }
    };
}