package org.apache.lucene.index.codecs;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
import org.apache.lucene.index.DocsEnum;
import org.apache.lucene.index.MultiDocsEnum;
import java.io.IOException;
/**
* Exposes flex API, merged from flex API of sub-segments,
* remapping docIDs (this is used for segment merging).
*
* @lucene.experimental
*/
public final class MappingMultiDocsEnum extends DocsEnum {
private MultiDocsEnum.EnumWithSlice[] subs;
int numSubs;
int upto;
int[] currentMap;
DocsEnum current;
int currentBase;
int doc = -1;
private MergeState mergeState;
MappingMultiDocsEnum reset(MultiDocsEnum docsEnum) throws IOException {
this.numSubs = docsEnum.getNumSubs();
this.subs = docsEnum.getSubs();
upto = -1;
current = null;
return this;
}
public void setMergeState(MergeState mergeState) {
this.mergeState = mergeState;
}
@Override
public int freq() {
return current.freq();
}
@Override
public int docID() {
return doc;
}
@Override
public int advance(int target) throws IOException {
throw new UnsupportedOperationException();
}
@Override
public int nextDoc() throws IOException {
while(true) {
if (current == null) {
if (upto == numSubs-1) {
return this.doc = NO_MORE_DOCS;
} else {
upto++;
final int reader = subs[upto].slice.readerIndex;
current = subs[upto].docsEnum;
currentBase = mergeState.docBase[reader];
currentMap = mergeState.docMaps[reader];
}
}
int doc = current.nextDoc();
if (doc != NO_MORE_DOCS) {
if (currentMap != null) {
// compact deletions
doc = currentMap[doc];
if (doc == -1) {
continue;
}
}
return this.doc = currentBase + doc;
} else {
current = null;
}
}
}
}