Page History

 public static final byte NULL_ARRAY = -1; // array is null
  /**
   * @since GemFire 5.7
   */
  private static final byte SHORT_ARRAY_LEN = -2; // array len encoded as unsigned short in next 2
                                                  // bytes
  /**
   * @since GemFire 5.7
   */
  public static final byte INT_ARRAY_LEN = -3; // array len encoded as int in next 4 bytes
  private static final int MAX_BYTE_ARRAY_LEN = ((byte) -4) & 0xFF;
  public static void writeArrayLength(int len, DataOutput out) throws IOException {
    if (len == -1) {
      out.writeByte(NULL_ARRAY);
    } else if (len <= MAX_BYTE_ARRAY_LEN) {
      out.writeByte(len);
    } else if (len <= 0xFFFF) {
      out.writeByte(SHORT_ARRAY_LEN);
      out.writeShort(len);
    } else {
      out.writeByte(INT_ARRAY_LEN);
      out.writeInt(len);
    }
  }

  public static int readArrayLength(DataInput in) throws IOException {
    byte code = in.readByte();
    if (code == NULL_ARRAY) {
      return -1;
    } else {
      int result = ubyteToInt(code);
      if (result > MAX_BYTE_ARRAY_LEN) {
        if (code == SHORT_ARRAY_LEN) {
          result = in.readUnsignedShort();
        } else if (code == INT_ARRAY_LEN) {
          result = in.readInt();
        } else {
          throw new IllegalStateException("unexpected array length code=" + code);
        }
      }
      return result;
    }
  }