Method insertTuple

src/java/simpledb/storage/HeapFile.java:127–158

(TransactionId tid, Tuple t)

    // see DbFile.java for javadocs
    public List<Page> insertTuple(TransactionId tid, Tuple t)
            throws DbException, IOException, TransactionAbortedException {
        // some code goes here
        if (!getFile().canRead() || !getFile().canWrite()) {
            throw new IOException();
        }
        List<Page> res = new ArrayList<>();
        for(int i=0;i<numPages();i++){
            HeapPageId heapPageId = new HeapPageId(getId(),i);
            HeapPage heapPage = (HeapPage) Database.getBufferPool().getPage(tid,heapPageId,Permissions.READ_ONLY);
            if(heapPage==null){
                Database.getBufferPool().unsafeReleasePage(tid,heapPageId);
                continue;
            }
            if(heapPage.getNumEmptySlots()==0){
                Database.getBufferPool().unsafeReleasePage(tid,heapPageId);
                continue;
            }
            heapPage.insertTuple(t);
            heapPage.markDirty(true,tid);
            res.add(heapPage);
            return res;
        }
        //新建一个page
        HeapPageId heapPageId = new HeapPageId(getId(), numPages());
        HeapPage heapPage = new HeapPage(heapPageId, HeapPage.createEmptyPageData());
        heapPage.insertTuple(t);
        writePage(heapPage);
        res.add(heapPage);
        return res;
        // not necessary for lab1
    }

    // see DbFile.java for javadocs
    public ArrayList<Page> deleteTuple(TransactionId tid, Tuple t) throws DbException,