package org.infinispan.lucene.impl;
import java.io.Closeable;
import java.io.IOException;
import org.apache.lucene.store.Lock;
import org.infinispan.Cache;
import org.infinispan.context.Flag;
import org.infinispan.lucene.FileCacheKey;
import org.infinispan.lucene.InvalidLockException;
import org.infinispan.remoting.transport.Address;
import org.infinispan.remoting.transport.LocalModeAddress;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
/**
* Inter-IndexWriter Lucene index lock based on Infinispan.
* This implementation is not bound to and does not need a TransactionManager,
* is more suited for large batch work and index optimization.
*
* @since 4.0
* @author Sanne Grinovero
* @see org.apache.lucene.store.Lock
*/
@SuppressWarnings("unchecked")
class BaseLuceneLock extends Lock implements Closeable, ObtainableLock {
private static final Log log = LogFactory.getLog(BaseLuceneLock.class);
private static final boolean trace = log.isTraceEnabled();
private final Cache<Object, Object> noCacheStoreCache;
private final String lockName;
private final String indexName;
private final FileCacheKey keyOfLock;
private final Address valueOfLock;
BaseLuceneLock(Cache<?, ?> cache, String indexName, String lockName, int affinitySegmentId) {
this.noCacheStoreCache = (Cache<Object, Object>) cache.getAdvancedCache().withFlags(Flag.SKIP_CACHE_STORE, Flag.SKIP_CACHE_LOAD);
this.lockName = lockName;
this.indexName = indexName;
this.keyOfLock = new FileCacheKey(indexName, lockName, affinitySegmentId);
Address address = noCacheStoreCache.getCacheManager().getAddress();
this.valueOfLock = address == null ? LocalModeAddress.INSTANCE : address;
}
@Override
public boolean obtain() {
Object previousValue = noCacheStoreCache.putIfAbsent(keyOfLock, valueOfLock);
if (trace) log.tracef("Result of lock acquiring %s", previousValue);
if (previousValue == null) {
if (trace) {
log.tracef("Lock: %s acquired for index: %s from %s", lockName, indexName, valueOfLock);
}
// we own the lock:
return true;
} else {
if (trace) {
log.tracef("Lock: %s not acquired for index: %s from %s, was taken already by %s.", lockName,
indexName, valueOfLock, previousValue);
}
return false;
}
}
public void clearLock() {
Object lockOwner = noCacheStoreCache.get(keyOfLock);
if (lockOwner == null || valueOfLock.equals(lockOwner)) {
Object previousValue = noCacheStoreCache.remove(keyOfLock);
log.tracef("Lock: %s removed for index: %s from %s (was %s)", lockName, indexName, valueOfLock, previousValue);
} else {
log.tracef("Lock: %s not cleared for index: %s from %s, was taken already by %s.", lockName,
indexName, valueOfLock, lockOwner);
}
}
public boolean isLocked() {
return noCacheStoreCache.containsKey(keyOfLock);
}
/**
* Since Lucene 4.7, method release() was renamed to close()
*/
@Override
public void close() {
clearLock();
}
@Override
public void ensureValid() throws IOException {
if (!isLocked()) {
throw new InvalidLockException("This lock is no longer being held");
}
}
}