/*
* 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.
*/
package org.apache.jackrabbit.core.query.lucene.hits;
import java.util.Arrays;
/**
* Uses an integer array to store the hit set. This implementation uses less
* memory than {@link BitSetHits} if the total number of documents is high and
* and the number of hits is low or if your hits doc numbers are mostly in the
* upper part of your doc number range.
* If you don't know about your hit distribution in advance use
* {@link AdaptingHits} instead.
*/
public class ArrayHits implements Hits {
private static final int INITIAL_SIZE = 100;
private int[] hits;
private int index;
private boolean initialized;
public ArrayHits() {
this(INITIAL_SIZE);
}
public ArrayHits(int initialSize) {
hits = new int[initialSize];
index = 0;
initialized = false;
}
private void initialize() {
if (!initialized) {
Arrays.sort(hits);
index = hits.length - index;
initialized = true;
}
}
/**
* {@inheritDoc}
*/
public void set(int doc) {
if (initialized) {
throw new IllegalStateException(
"You must not call set() after next() or skipTo()");
}
if (index >= hits.length) {
int[] resizedHits = new int[hits.length * 2];
System.arraycopy(hits, 0, resizedHits, 0, hits.length);
hits = resizedHits;
}
hits[index++] = doc;
}
/**
* {@inheritDoc}
*/
public int next() {
initialize();
if (index >= hits.length) {
return -1;
} else {
return hits[index++];
}
}
/**
* {@inheritDoc}
*/
public int skipTo(int target) {
initialize();
for (int i = index; i < hits.length; i++) {
int nextDocValue = hits[i];
if (nextDocValue >= target) {
index = i;
return next();
}
}
return -1;
}
}