/*
*
* * Copyright 2014 Orient Technologies LTD (info(at)orientechnologies.com)
* *
* * Licensed 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.
* *
* * For more information: http://www.orientechnologies.com
*
*/
package com.orientechnologies.orient.core.db.record;
import java.util.Iterator;
import com.orientechnologies.common.collection.OLazyIterator;
import com.orientechnologies.common.log.OLogManager;
import com.orientechnologies.common.util.OResettable;
import com.orientechnologies.orient.core.db.ODatabaseRecordThreadLocal;
import com.orientechnologies.orient.core.id.ORecordId;
import com.orientechnologies.orient.core.record.ORecord;
/**
* Lazy implementation of Iterator that load the records only when accessed. It keep also track of changes to the source record
* avoiding to call setDirty() by hand.
*
* @author Luca Garulli (l.garulli--at--orientechnologies.com)
*
*/
public class OLazyRecordIterator implements OLazyIterator<OIdentifiable>, OResettable {
final private ORecord sourceRecord;
final private Iterable<? extends OIdentifiable> source;
private Iterator<? extends OIdentifiable> underlying;
final private boolean autoConvert2Record;
public OLazyRecordIterator(final Iterator<? extends OIdentifiable> iIterator, final boolean iConvertToRecord) {
this.sourceRecord = null;
this.underlying = iIterator;
this.autoConvert2Record = iConvertToRecord;
this.source = null;
}
public OLazyRecordIterator(final ORecord iSourceRecord, final Iterator<? extends OIdentifiable> iIterator,
final boolean iConvertToRecord) {
this.sourceRecord = iSourceRecord;
this.underlying = iIterator;
this.autoConvert2Record = iConvertToRecord;
this.source = null;
}
public OLazyRecordIterator(final Iterable<? extends OIdentifiable> iSource, final boolean iConvertToRecord) {
this.sourceRecord = null;
this.autoConvert2Record = iConvertToRecord;
this.source = iSource;
this.underlying = iSource.iterator();
}
@SuppressWarnings("unchecked")
public OIdentifiable next() {
OIdentifiable value = underlying.next();
if (value == null)
return null;
if (value instanceof ORecordId && autoConvert2Record && ODatabaseRecordThreadLocal.INSTANCE.isDefined()) {
try {
final ORecord rec = ((ORecordId) value).getRecord();
if (underlying instanceof OLazyIterator<?>)
((OLazyIterator<OIdentifiable>) underlying).update(rec);
value = rec;
} catch (Exception e) {
OLogManager.instance().error(this, "Error on iterating record collection", e);
value = null;
}
}
return value;
}
public boolean hasNext() {
return underlying.hasNext();
}
@SuppressWarnings("unchecked")
public OIdentifiable update(final OIdentifiable iValue) {
if (underlying instanceof OLazyIterator) {
final OIdentifiable old = ((OLazyIterator<OIdentifiable>) underlying).update(iValue);
if (sourceRecord != null && !old.equals(iValue))
sourceRecord.setDirty();
return old;
} else
throw new UnsupportedOperationException("Underlying iterator not supports lazy updates (Interface OLazyIterator");
}
public void remove() {
underlying.remove();
if (sourceRecord != null)
sourceRecord.setDirty();
}
@Override
public void reset() {
if (underlying instanceof OResettable)
((OResettable) underlying).reset();
else if (source != null) {
underlying = source.iterator();
}
}
}