| /* |
| * Copyright 2017 HugeGraph Authors |
| * |
| * 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 com.baidu.hugegraph.iterator; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import com.baidu.hugegraph.util.InsertionOrderUtil; |
| |
| public class ListIterator<T> extends WrappedIterator<T> { |
| |
| private final Iterator<T> originIterator; |
| private final Iterator<T> resultsIterator; |
| private final Collection<T> results; |
| |
| public ListIterator(long capacity, Iterator<T> origin) { |
| List<T> results = InsertionOrderUtil.newList(); |
| while (origin.hasNext()) { |
| if (capacity >= 0L && results.size() >= capacity) { |
| throw new IllegalArgumentException( |
| "The iterator exceeded capacity " + capacity); |
| } |
| results.add(origin.next()); |
| } |
| this.originIterator = origin; |
| this.results = Collections.unmodifiableList(results); |
| this.resultsIterator = this.results.iterator(); |
| } |
| |
| public ListIterator(Collection<T> origin) { |
| this.originIterator = origin.iterator(); |
| this.results = origin instanceof List ? |
| Collections.unmodifiableList((List<T>) origin) : |
| Collections.unmodifiableCollection(origin); |
| this.resultsIterator = this.results.iterator(); |
| } |
| |
| @Override |
| public void remove() { |
| this.resultsIterator.remove(); |
| } |
| |
| public Collection<T> list() { |
| return this.results; |
| } |
| |
| @Override |
| protected boolean fetch() { |
| assert this.current == none(); |
| if (!this.resultsIterator.hasNext()) { |
| return false; |
| } |
| this.current = this.resultsIterator.next(); |
| return true; |
| } |
| |
| @Override |
| protected Iterator<T> originIterator() { |
| return this.originIterator; |
| } |
| } |