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.psagent.matrix.storage;
  
  /**
   * The storage for a single matrix.
   */
  
  import com.tencent.angel.ml.math2.vector.Vector;
  
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  public class MatrixStorage {
    /**
     * row index to row map
     */
    private final ConcurrentHashMap<Integer, Vector> rowIndexToRowMap;
    private final ReentrantReadWriteLock lock;
  
    /**
     * Create a new MatrixStorage.
     */
    public MatrixStorage() {
      rowIndexToRowMap = new ConcurrentHashMap<>();
      lock = new ReentrantReadWriteLock();
    }
  
    /**
     * Get the row from the storage.
     *
     * @param rowIndex row index
     * @return TVector row
     */
    public Vector getRow(int rowIndex) {
      return rowIndexToRowMap.get(rowIndex);
    }
  
    /**
     * Add the row to the storage.
     *
     * @param rowIndex row index
     * @param row
     */
    public void addRow(int rowIndex, Vector row) {
      rowIndexToRowMap.put(rowIndex, row);
    }
  
    /**
     * Remove the row from the storage.
     *
     * @param rowIndex row index
     */
    public void removeRow(int rowIndex) {
      rowIndexToRowMap.remove(rowIndex);
    }
  
    public ReentrantReadWriteLock getLock() {
      return lock;
    }
  }
  