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.spark.ml.tree.util;
  
  public class BufferedBitSetWriter {
  
    //private final SerializableBuffer bytes;
    //private final ByteBuffer bytes;
    private final byte[] bytes;
    private int writeIndex;
    private int writeOffset;
    private int writeBuffer;
  
    public BufferedBitSetWriter(int capacity) {
      int numBytes = (int) Math.ceil(1.0 * capacity / 8);
      //this.bytes = ByteBuffer.allocate(numBytes);
      this.bytes = new byte[numBytes];
    }
  
    //public BufferedBitSetWriter(ByteBuffer bytes) {
    //    this.bytes = bytes;
    //}
  
    public BufferedBitSetWriter(byte[] bytes) {
      this.bytes = bytes;
    }
  
    public void write(boolean bit) {
      writeBuffer = writeBuffer << 1;
      if (bit) {
        writeBuffer |= 1;
      }
      if (++writeOffset == 8) {
        writeToBuffer();
      }
    }
  
    private void writeToBuffer() {
      //bytes.put(writeIndex++, (byte) writeBuffer);
      bytes[writeIndex++] = (byte) writeBuffer;
      writeOffset = 0;
      writeBuffer = 0;
    }
  
    public void complete() {
      if (writeOffset != 0) {
        writeBuffer <<= 8 - writeOffset;
        writeToBuffer();
      }
    }
  
    //public ByteBuffer getBytes() {
    //    return bytes;
    //}
  
  
    public byte[] getBytes() {
      return bytes;
    }
  }
  