| /* |
| * Copyright 2000-2010 JetBrains s.r.o. |
| * |
| * Licensed 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.intellij.openapi.editor.impl.softwrap.mapping; |
| |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.util.List; |
| |
| /** |
| * Generic {@link DataProvider} implementation that assumes that target data is available as list. |
| * <p/> |
| * Not thread-safe. |
| * |
| * @author Denis Zhdanov |
| * @since Aug 31, 2010 12:56:58 PM |
| */ |
| public abstract class AbstractListBasedDataProvider<K extends Comparable<? super K>, V> extends AbstractDataProvider<K, V> { |
| |
| private final List<V> myData; |
| private int myIndex; |
| |
| public AbstractListBasedDataProvider(@NotNull K key, @NotNull List<V> data) { |
| super(key); |
| |
| // We use given collection instead of copying it to private list because profiling indicates that as an expensive operation |
| // when performed frequently. |
| myData = data; |
| } |
| |
| @Override |
| protected V doGetData() { |
| if (myIndex < myData.size()) { |
| return myData.get(myIndex); |
| } |
| return null; |
| } |
| |
| @Override |
| public boolean next() { |
| return ++myIndex < myData.size(); |
| } |
| |
| @Override |
| public void advance(int sortingKey) { |
| |
| // We inline binary search here because profiling indicates that as a performance boost. |
| int start = myIndex; |
| int end = myData.size() - 1; |
| |
| // We inline binary search here because profiling indicates that it becomes bottleneck to use Collections.binarySearch(). |
| while (start <= end) { |
| int i = (end + start) >>> 1; |
| V data = myData.get(i); |
| if (getSortingKey(data) < sortingKey) { |
| start = i + 1; |
| continue; |
| } |
| if (getSortingKey(data) > sortingKey) { |
| end = i - 1; |
| continue; |
| } |
| |
| myIndex = i; |
| return; |
| } |
| myIndex = start; |
| } |
| |
| @Override |
| public int getSortingKey() { |
| if (myIndex < myData.size()) { |
| return getSortingKey(myData.get(myIndex)); |
| } |
| return 0; |
| } |
| |
| /** |
| * Sub-classes are expected to be able to derive sorting key for the every data instance. |
| * |
| * @param data target data which sorting key should be returned |
| * @return sorting key for the given data |
| */ |
| protected abstract int getSortingKey(@NotNull V data); |
| } |