| // Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| package com.android.tools.r8.utils; |
| |
| import com.android.tools.r8.errors.InternalCompilerError; |
| import com.android.tools.r8.graph.KeyedDexItem; |
| import com.android.tools.r8.graph.PresortedComparable; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| public class OrderedMergingIterator<T extends KeyedDexItem<S>, S extends PresortedComparable<S>> |
| implements Iterator<T> { |
| |
| private final List<T> one; |
| private final List<T> other; |
| private int oneIndex = 0; |
| private int otherIndex = 0; |
| |
| public OrderedMergingIterator(List<T> one, List<T> other) { |
| this.one = one; |
| this.other = other; |
| } |
| |
| private static <T> T getNextChecked(List<T> list, int position) { |
| if (position >= list.size()) { |
| throw new NoSuchElementException(); |
| } |
| return list.get(position); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return oneIndex < one.size() || otherIndex < other.size(); |
| } |
| |
| @Override |
| public T next() { |
| if (oneIndex >= one.size()) { |
| return getNextChecked(other, otherIndex++); |
| } |
| if (otherIndex >= other.size()) { |
| return getNextChecked(one, oneIndex++); |
| } |
| int comparison = one.get(oneIndex).getKey().compareTo(other.get(otherIndex).getKey()); |
| if (comparison < 0) { |
| return one.get(oneIndex++); |
| } |
| if (comparison == 0) { |
| throw new InternalCompilerError("Source arrays are not disjoint."); |
| } |
| return other.get(otherIndex++); |
| } |
| } |