modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/MvccVersion.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.processors.cache.mvcc;

import org.jetbrains.annotations.NotNull;

/**
 * MVCC version. This is unique version allowing to order all reads and writes within a cluster. Consists of two parts:
 * - coordinator version - number which increases on every coordinator change;
 * - counter - local coordinator counter which is increased on every update.
 */
public interface MvccVersion extends Comparable<MvccVersion> {
    /**
     * @return Coordinator version.
     */
    public long coordinatorVersion();

    /**
     * @return Local counter.
     */
    public long counter();

    /**
     * @return Operation id in scope of current transaction.
     */
    public int operationCounter();

    /** {@inheritDoc} */
    @Override default int compareTo(@NotNull MvccVersion another) {
        return MvccUtils.compare(coordinatorVersion(), counter(), operationCounter(),
            another.coordinatorVersion(), another.counter(), another.operationCounter());
    }
}