@Override
  public void fromData(DataInput in) throws IOException, ClassNotFoundException {
    className = DataSerializer.readString(in);
    swizzleGemFireClassNames();
    {
      byte bits = in.readByte();
      noDomainClass = (bits & NO_DOMAIN_CLASS_BIT) != 0;
      hasDeletedField = (bits & HAS_DELETED_FIELD_BIT) != 0;
    }

    typeId = in.readInt();
    vlfCount = in.readInt();

    int arrayLen = InternalDataSerializer.readArrayLength(in);

    for (int i = 0; i < arrayLen; i++) {
      PdxField vft = new PdxField();
      vft.fromData(in);
      addField(vft);
    }
  }
A count of the total number of variable length field offsets.
geode-core/src/main/java/org/apache/geode/pdx/internal/PdxType.java