*/
package org.opendaylight.yangtools.util;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ForwardingMap;
import java.util.Map;
-
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import org.opendaylight.yangtools.triemap.ImmutableTrieMap;
+import org.opendaylight.yangtools.triemap.MutableTrieMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ForwardingMap;
-import com.romix.scala.collection.concurrent.TrieMap;
-
/**
* A read-only facade in front of a TrieMap. This is what we give out from
* MapAdaptor.optimize(). The idea is that we want our read-only users to
* changes, we can cache it for future reference.
*/
final class ReadOnlyTrieMap<K, V> extends ForwardingMap<K, V> {
+ @SuppressWarnings("rawtypes")
+ private static final AtomicReferenceFieldUpdater<ReadOnlyTrieMap, ImmutableTrieMap> UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(ReadOnlyTrieMap.class, ImmutableTrieMap.class, "readOnly");
private static final Logger LOG = LoggerFactory.getLogger(ReadOnlyTrieMap.class);
- private final TrieMap<K, V> readWrite;
+ private final MutableTrieMap<K, V> readWrite;
private final int size;
- private volatile TrieMap<K, V> readOnly;
+ private volatile ImmutableTrieMap<K, V> readOnly;
- ReadOnlyTrieMap(final TrieMap<K, V> map, final int size) {
- super();
+ ReadOnlyTrieMap(final MutableTrieMap<K, V> map, final int size) {
this.readWrite = Preconditions.checkNotNull(map);
this.size = size;
}
Map<K, V> toReadWrite() {
- final Map<K, V> ret = new ReadWriteTrieMap<>(readWrite.snapshot(), size);
+ final Map<K, V> ret = new ReadWriteTrieMap<>(readWrite.mutableSnapshot(), size);
LOG.trace("Converted read-only TrieMap {} to read-write {}", this, ret);
return ret;
}
@Override
protected Map<K, V> delegate() {
- TrieMap<K, V> ret = readOnly;
+ ImmutableTrieMap<K, V> ret = readOnly;
if (ret == null) {
- synchronized (this) {
+ ret = readWrite.immutableSnapshot();
+ if (!UPDATER.compareAndSet(this, null, ret)) {
ret = readOnly;
- if (ret == null) {
- ret = readWrite.readOnlySnapshot();
- readOnly = ret;
- }
}
}
-
return ret;
}