com.bigdata.rwstore.RWWriteCacheService Maven / Gradle / Ivy
/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
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 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}.
*
* 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 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) opener, fileExtent,
null/* BufferedWrite */);
}
@Override
public boolean removeWriteToAddr(final long address, final int latchedAddr) {
return clearWrite(address, latchedAddr);
}
}