| /* |
| * 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.lucene.search.suggest; |
| |
| import java.io.IOException; |
| import java.util.Random; |
| import java.util.Set; |
| |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.BytesRefBuilder; |
| |
| /** |
| * This wrapper buffers the incoming elements and makes sure they are in |
| * random order. |
| * @lucene.experimental |
| */ |
| public class UnsortedInputIterator extends BufferedInputIterator { |
| // TODO keep this for now |
| private final int[] ords; |
| private int currentOrd = -1; |
| private final BytesRefBuilder spare = new BytesRefBuilder(); |
| private final BytesRefBuilder payloadSpare = new BytesRefBuilder(); |
| /** |
| * Creates a new iterator, wrapping the specified iterator and |
| * returning elements in a random order. |
| */ |
| public UnsortedInputIterator(InputIterator source) throws IOException { |
| super(source); |
| ords = new int[entries.size()]; |
| Random random = new Random(); |
| for (int i = 0; i < ords.length; i++) { |
| ords[i] = i; |
| } |
| for (int i = 0; i < ords.length; i++) { |
| int randomPosition = random.nextInt(ords.length); |
| int temp = ords[i]; |
| ords[i] = ords[randomPosition]; |
| ords[randomPosition] = temp; |
| } |
| } |
| |
| @Override |
| public long weight() { |
| assert currentOrd == ords[curPos]; |
| return freqs[currentOrd]; |
| } |
| |
| @Override |
| public BytesRef next() throws IOException { |
| if (++curPos < entries.size()) { |
| currentOrd = ords[curPos]; |
| return entries.get(spare, currentOrd); |
| } |
| return null; |
| } |
| |
| @Override |
| public BytesRef payload() { |
| if (hasPayloads() && curPos < payloads.size()) { |
| assert currentOrd == ords[curPos]; |
| return payloads.get(payloadSpare, currentOrd); |
| } |
| return null; |
| } |
| |
| @Override |
| public Set<BytesRef> contexts() { |
| if (hasContexts() && curPos < contextSets.size()) { |
| assert currentOrd == ords[curPos]; |
| return contextSets.get(currentOrd); |
| } |
| return null; |
| } |
| } |