@Override
public void readFields(DataInput in) throws IOException {
// read head (rows, cols)
_numRows = in.readInt();
int numCols = in.readInt();
// read columns (value type, data)
_schema.clear();
_coldata.clear();
for (int j = 0; j < numCols; j++) {
ValueType vt = ValueType.values()[in.readByte()];
String name = in.readUTF();
Array arr = null;
switch (vt) {
case STRING:
arr = new StringArray(new String[_numRows]);
break;
case BOOLEAN:
arr = new BooleanArray(new boolean[_numRows]);
break;
case INT:
arr = new LongArray(new long[_numRows]);
break;
case DOUBLE:
arr = new DoubleArray(new double[_numRows]);
break;
default:
throw new IOException("Unsupported value type: " + vt);
}
arr.readFields(in);
_schema.add(vt);
_colnames.add(name);
_coldata.add(arr);
}
}