// see DbFile.java for javadocs
public ArrayList<Page> insertTuple(TransactionId tid, Tuple t)
throws DbException, IOException, TransactionAbortedException {
// some code goes here
BufferPool bp = Database.getBufferPool();
int id = getId(), i, slots;
ArrayList<Page> retlist = new ArrayList<Page>();
PageId pid = null;
HeapPage p = null;
for (i = 0; i < numPages(); i++) {
pid = new HeapPageId(id, i);
p = (HeapPage) bp.getPage(tid, pid, Permissions.READ_WRITE);
slots = p.getNumEmptySlots();
if (slots > 0) {
p.insertTuple(t);
retlist.add(p);
return retlist;
}
}
// create new page and add tuple to it
pid = new HeapPageId(id, i);
raf.setLength(raf.length() + BufferPool.PAGE_SIZE);
p = (HeapPage) bp.getPage(tid, pid, Permissions.READ_WRITE);
p.insertTuple(t);
retlist.add(p);
return retlist;
}
private Page readPage(int pageNumber)
throws DbException, TransactionAbortedException, IOException {
// File == table because we do one file per table
// System.out.println("readpage:"+_file.id()+" page:"+pageNumber);
int tableId = _file.id();
int pageId = pageNumber;
// System.out.println("Page is now "+pageNumber);
HeapPageId pid = new HeapPageId(tableId, pageId);
return Database.getBufferPool().getPage(_transactionId, pid, Permissions.READ_ONLY);
}
// 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;
}