content: /*
   * Tencent is pleased to support the open source community by making Angel available.
   *
   * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
   *
   * 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
   *
   * https://opensource.org/licenses/Apache-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.tencent.angel.sona.tree.basic;
  
  import com.tencent.angel.sona.tree.basic.split.SplitEntry;
  
  import java.io.Serializable;
  
  /**
   * The abstract class for tree node.
   *
   */
  public abstract class TNode implements Serializable {
      /**
       * Metadata for tree node. Tree node index starts from 0.
       */
      private final int nid;
      private final TNode parent;
      private TNode leftChild;
      private TNode rightChild;
      private SplitEntry splitEntry;
      private boolean isLeaf;
  
      public TNode(int nid, TNode parent, TNode leftChild, TNode rightChild) {
          this.nid = nid;
          this.parent = parent;
          this.leftChild = leftChild;
          this.rightChild = rightChild;
          this.isLeaf = false;
      }
  
      public TNode(int nid, TNode parent) {
          this(nid, parent, null, null);
      }
  
      public int getNid() {
          return nid;
      }
  
      public TNode getParent() {
          return parent;
      }
  
      public TNode getLeftChild() {
          return leftChild;
      }
  
      public void setLeftChild(TNode leftChild) {
          this.leftChild = leftChild;
      }
  
      public TNode getRightChild() {
          return rightChild;
      }
  
      public void setRightChild(TNode rightChild) {
          this.rightChild = rightChild;
      }
  
      public SplitEntry getSplitEntry() {
          return splitEntry;
      }
  
      public void setSplitEntry(SplitEntry splitEntry) {
          this.splitEntry = splitEntry;
      }
  
      public boolean isLeaf() {
          return isLeaf;
      }
  
      public void chgToLeaf() {
          isLeaf = true;
      }
  
  }
  