package proj.zoie.api.impl.util;
/**
* 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 java.io.IOException;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
public class ArrayDocIdSet extends DocIdSet
{
private final int[] _docids;
private final int _lengthminusone;
public ArrayDocIdSet(int[] docids)
{
_docids = docids;
if (docids!=null)
_lengthminusone = docids.length - 1;
else
_lengthminusone = -1;
}
final private static int binarySearch(int[] a, int key) {
return binarySearch(a, key, 0, a.length-1);
}
final private static int binarySearch(int[] a, int key, int low, int high) {
while (low <= high) {
int mid = (low + high) >>> 1;
int midVal = a[mid];
int cmp;
cmp = midVal - key;
if (cmp < 0)
low = mid + 1;
else if (cmp > 0)
high = mid - 1;
else
return mid;
}
return -(low + 1);
}
@Override
public DocIdSetIterator iterator()
{
return new DocIdSetIterator()
{
int doc = -1;
int current = -1;
int largest = _lengthminusone;
@Override
public int docID()
{
return doc;
}
@Override
public int nextDoc() throws IOException
{
if (current<_lengthminusone)
{
current++;
doc = _docids[current];
return doc;
}
return DocIdSetIterator.NO_MORE_DOCS;
}
@Override
public int advance(int target) throws IOException
{
int idx = current < 0 ? binarySearch(_docids,target) : binarySearch(_docids,target,current,largest);
// int idx = Arrays.binarySearch(_docids,target);
if (idx < 0)
{
idx = -(idx+1);
if (idx>=_docids.length) return DocIdSetIterator.NO_MORE_DOCS;
}
current = idx;
doc = _docids[current];
return doc;
}
};
}
}