/**

Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016.  All rights reserved.

Contact:
     SYSTAP, LLC DBA Blazegraph
     2501 Calvert ST NW #106
     Washington, DC 20008
     licenses@blazegraph.com

This program 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; version 2 of the License.

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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

package com.bigdata.rwstore;

import java.io.IOException;
import java.nio.channels.Channel;
import java.nio.channels.FileChannel;

import org.apache.log4j.Logger;

import com.bigdata.io.IBufferAccess;
import com.bigdata.io.IReopenChannel;
import com.bigdata.io.writecache.IBackingReader;
import com.bigdata.io.writecache.WriteCache;
import com.bigdata.io.writecache.WriteCache.FileChannelScatteredWriteCache;
import com.bigdata.io.writecache.WriteCacheService;
import com.bigdata.quorum.Quorum;

/**
 * Defines the WriteCacheService to be used by the RWStore.
 * 
 * @author mgc
 */
public class RWWriteCacheService extends WriteCacheService implements IWriteCacheManager {

    protected static final Logger log = Logger.getLogger(RWWriteCacheService.class);
    
    public RWWriteCacheService(final int nbuffers, final int minCleanListSize, final int readBuffers,
            final boolean prefixWrites, final int compactionThreshold,
            final int hotCacheSize, final int hotCacheThreshold,
            final long fileExtent,
            final IReopenChannel<? extends Channel> opener, final Quorum quorum,
            final IBackingReader reader)
            throws InterruptedException, IOException {

        super(nbuffers, minCleanListSize,  readBuffers, prefixWrites, compactionThreshold, hotCacheSize, hotCacheThreshold,
                true/* useChecksum */, fileExtent, opener, quorum, reader);
    }

    /**
     * The scattered write cache supports compaction.
     */
    @Override
    protected final boolean canCompact() {
        return true;
    }

    /**
     * Provide default {@link FileChannelScatteredWriteCache}.
     * <p>
     * Note: This is used by the unit tests, but not by the {@link RWStore}.
     */
    @Override
    public WriteCache newWriteCache(final IBufferAccess buf,
            final boolean useChecksum,
            final boolean bufferHasData,
            final IReopenChannel<? extends Channel> opener,
            final long fileExtent)
            throws InterruptedException {

//        final boolean highlyAvailable = getQuorum() != null
//                && getQuorum().isHighlyAvailable();
        final boolean highlyAvailable = getQuorum() != null;

        return new FileChannelScatteredWriteCache(buf, true/* useChecksum */,
                highlyAvailable,
                bufferHasData,
                (IReopenChannel<FileChannel>) opener, fileExtent,
                null/* BufferedWrite */);

    }

    @Override
    public boolean removeWriteToAddr(final long address, final int latchedAddr) {

        return clearWrite(address, latchedAddr);

    }
    
}