| /* |
| * 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.flink.runtime.state.heap; |
| |
| import org.apache.flink.annotation.VisibleForTesting; |
| import org.apache.flink.util.Preconditions; |
| |
| import static org.apache.flink.runtime.state.heap.SkipListUtils.DEFAULT_LEVEL; |
| import static org.apache.flink.runtime.state.heap.SkipListUtils.MAX_LEVEL; |
| import static org.apache.flink.runtime.state.heap.SkipListUtils.NIL_NODE; |
| |
| /** Implementation of {@link LevelIndexHeader} which stores index on heap. */ |
| public class OnHeapLevelIndexHeader implements LevelIndexHeader { |
| |
| /** The level index array where each position stores the next node id of the level. */ |
| private volatile long[] levelIndex; |
| |
| /** The topmost level currently. */ |
| private volatile int topLevel; |
| |
| /** Next node at level 0. */ |
| private volatile long nextNode; |
| |
| OnHeapLevelIndexHeader() { |
| this(DEFAULT_LEVEL); |
| } |
| |
| private OnHeapLevelIndexHeader(int maxLevel) { |
| Preconditions.checkArgument( |
| maxLevel >= 1 && maxLevel <= MAX_LEVEL, |
| "maxLevel(" + maxLevel + ") must be non-negative and no more than " + MAX_LEVEL); |
| this.topLevel = 1; |
| this.nextNode = NIL_NODE; |
| this.levelIndex = new long[maxLevel]; |
| initLevelIndex(levelIndex); |
| } |
| |
| private void initLevelIndex(long[] levelIndex) { |
| for (int i = 0; i < levelIndex.length; i++) { |
| levelIndex[i] = NIL_NODE; |
| } |
| } |
| |
| @Override |
| public int getLevel() { |
| return topLevel; |
| } |
| |
| @Override |
| public void updateLevel(int level) { |
| Preconditions.checkArgument( |
| level >= 0 && level <= MAX_LEVEL, |
| "level(" + level + ") must be non-negative and no more than " + MAX_LEVEL); |
| Preconditions.checkArgument( |
| level <= this.topLevel + 1, |
| "top level " |
| + topLevel |
| + " must be updated level by level, but new level is " |
| + level); |
| |
| if (levelIndex.length < level) { |
| long[] newLevelIndex = new long[this.levelIndex.length * 2]; |
| initLevelIndex(newLevelIndex); |
| System.arraycopy(this.levelIndex, 0, newLevelIndex, 0, this.levelIndex.length); |
| this.levelIndex = newLevelIndex; |
| } |
| |
| if (topLevel < level) { |
| topLevel = level; |
| } |
| } |
| |
| @Override |
| public long getNextNode(int level) { |
| Preconditions.checkArgument( |
| level >= 0 && level <= topLevel, |
| "invalid level " + level + " current top level is " + topLevel); |
| |
| if (level == 0) { |
| return nextNode; |
| } |
| return levelIndex[level - 1]; |
| } |
| |
| @Override |
| public void updateNextNode(int level, long node) { |
| Preconditions.checkArgument( |
| level >= 0 && level <= topLevel, |
| "invalid level " + level + " current top level is " + topLevel); |
| |
| if (level == 0) { |
| nextNode = node; |
| } else { |
| levelIndex[level - 1] = node; |
| } |
| } |
| |
| @VisibleForTesting |
| long[] getLevelIndex() { |
| return levelIndex; |
| } |
| } |