Method testRewind

test/simpledb/systemtest/ScanTest.java:53–74

Test that rewinding a SeqScan iterator works.

()

    /** Test that rewinding a SeqScan iterator works. */
    @Test public void testRewind() throws IOException, DbException, TransactionAbortedException {
        List<List<Integer>> tuples = new ArrayList<>();
        HeapFile f = SystemTestUtil.createRandomHeapFile(2, 1000, null, tuples);

        TransactionId tid = new TransactionId();
        SeqScan scan = new SeqScan(tid, f.getId(), "table");
        scan.open();
        for (int i = 0; i < 100; ++i) {
            assertTrue(scan.hasNext());
            Tuple t = scan.next();
            assertEquals(tuples.get(i), SystemTestUtil.tupleToList(t));
        }

        scan.rewind();
        for (int i = 0; i < 100; ++i) {
            assertTrue(scan.hasNext());
            Tuple t = scan.next();
            assertEquals(tuples.get(i), SystemTestUtil.tupleToList(t));
        }
        scan.close();
        Database.getBufferPool().transactionComplete(tid);
    }

    /** Verifies that the buffer pool is actually caching data.
     * @throws TransactionAbortedException