modules/core/src/main/java/org/apache/ignite/internal/processors/cache/persistence/evict/FairFifoPageEvictionTracker.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.persistence.evict;

import java.util.LinkedList;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.IgniteException;
import org.apache.ignite.configuration.DataRegionConfiguration;
import org.apache.ignite.internal.pagemem.PageIdUtils;
import org.apache.ignite.internal.pagemem.impl.PageMemoryNoStoreImpl;
import org.apache.ignite.internal.processors.cache.GridCacheSharedContext;

/**
 * On-heap FIFO page eviction tracker. Only for test purposes.
 */
public class FairFifoPageEvictionTracker extends PageAbstractEvictionTracker {
    /** Page usage deque. */
    private final LinkedList<Integer> pageUsageList = new LinkedList<>();

    /**
     * @param pageMem Page memory.
     * @param plcCfg Data region configuration.
     * @param sharedCtx Shared context.
     */
    public FairFifoPageEvictionTracker(
        PageMemoryNoStoreImpl pageMem,
        DataRegionConfiguration plcCfg,
        GridCacheSharedContext sharedCtx) {
        super(pageMem, plcCfg, sharedCtx);
    }

    /** {@inheritDoc} */
    @Override public void start() throws IgniteException {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override public void stop() throws IgniteException {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override public synchronized void touchPage(long pageId) throws IgniteCheckedException {
        pageUsageList.addLast(PageIdUtils.pageIndex(pageId));
    }

    /** {@inheritDoc} */
    @Override public synchronized void evictDataPage() throws IgniteCheckedException {
        evictDataPage(pageUsageList.pollFirst());
    }

    /** {@inheritDoc} */
    @Override public synchronized void forgetPage(long pageId) throws IgniteCheckedException {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override protected synchronized boolean checkTouch(long pageId) {
        return true;
    }
}