/**
* Delete the specified tuple from the page; the tuple should be updated to reflect that it is no
* longer stored on any page.
*
* @throws DbException if this tuple is not on this page, or tuple slot is already empty.
* @param t The tuple to delete
*/
public void deleteTuple(Tuple t) throws DbException {
// some code goes here
// not necessary for lab1
RecordId targetrid = t.getRecordId();
int tslotnum = targetrid.tupleno();
if (!targetrid.getPageId().equals(pid) || !isSlotUsed(tslotnum)) {
throw new DbException("Either wrong page number or requested tuple didn't exist");
}
markSlotUsed(tslotnum, false);
tuples[tslotnum] = null;
}
// see DbFile.java for javadocs
public Page deleteTuple(TransactionId tid, Tuple t)
throws DbException, TransactionAbortedException {
// some code goes here
BufferPool bp = Database.getBufferPool();
RecordId rid = t.getRecordId();
if (rid == null) {
throw new DbException("Tuple is not a member of this file");
}
HeapPage p = (HeapPage) bp.getPage(tid, rid.getPageId(), Permissions.READ_WRITE);
p.deleteTuple(t);
return p;
}
/**
* 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;
}
}
}
/** 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.");
}
}
