@Override
public void readFields(DataInput input) throws IOException {
// read/write type ordinal, maxLength presence, scale presence and isNullable bit together to
// save space
int typeAndFlag = WritableUtils.readVInt(input);
isNullable = (typeAndFlag & 0x01) != 0;
if ((typeAndFlag & 0x02) != 0) {
scale = WritableUtils.readVInt(input);
}
if ((typeAndFlag & 0x04) != 0) {
maxLength = WritableUtils.readVInt(input);
}
type = PDataType.values()[typeAndFlag >>> 3];
sortOrder = SortOrder.fromSystemValue(WritableUtils.readVInt(input));
}
