/** Suck up tuples from the source file. */
private Tuple readNextTuple(DataInputStream dis, int slotId) throws NoSuchElementException {
// if associated bit is not set, read forward to the next tuple, and
// return null.
if (!isSlotUsed(slotId)) {
for (int i = 0; i < td.getSize(); i++) {
try {
dis.readByte();
} catch (IOException e) {
throw new NoSuchElementException("error reading empty tuple");
}
}
return null;
}
// read fields in the tuple
Tuple t = new Tuple(td);
RecordId rid = new RecordId(pid, slotId);
t.setRecordId(rid);
try {
for (int j = 0; j < td.numFields(); j++) {
Field f = td.getFieldType(j).parse(dis);
t.setField(j, f);
}
} catch (java.text.ParseException e) {
e.printStackTrace();
throw new NoSuchElementException("parsing error!");
}
return t;
}
/** Unit test for Tuple.getRecordId() and Tuple.setRecordId() */
@Test
public void modifyRecordId() {
Tuple tup1 = new Tuple(Utility.getTupleDesc(1));
HeapPageId pid1 = new HeapPageId(0, 0);
RecordId rid1 = new RecordId(pid1, 0);
tup1.setRecordId(rid1);
try {
assertEquals(rid1, tup1.getRecordId());
} catch (java.lang.UnsupportedOperationException e) {
// rethrow the exception with an explanation
throw new UnsupportedOperationException(
"modifyRecordId() test failed due to "
+ "RecordId.equals() not being implemented. This is not required for Lab 1, "
+ "but should pass when you do implement the RecordId class.");
}
}
/**
* Adds the specified tuple to the page; the tuple should be updated to reflect that it is now
* stored on this page.
*
* @throws DbException if the page is full (no empty slots) or tupledesc is mismatch.
* @param t The tuple to add.
*/
public void insertTuple(Tuple t) throws DbException {
// some code goes here
// not necessary for lab1
RecordId targetrid = t.getRecordId();
if (getNumEmptySlots() == 0 || !td.equals(t.getTupleDesc())) {
throw new DbException("Either page is full or tuple desc doesn't match");
}
for (int i = 0; i < getNumTuples(); i++) {
if (!isSlotUsed(i)) {
markSlotUsed(i, true);
RecordId rid = new RecordId(pid, i);
t.setRecordId(rid);
tuples[i] = t;
return;
}
}
}