[RATIS-471] `LogReader#readNext()` should return null or throw an error when reading off the end of the Log

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Component/s: LogService
• Assignee: Rajeshbabu Chintaguntla
• Reporter: Josh Elser
• Created: 09/Jan/19 16:18
• Updated: 18/Aug/23 00:22
• Resolved: 18/Aug/23 00:22

Description

    @Test
    public void testReadOffEndOfLog() throws Exception {
      try (LogServiceClient client = new LogServiceClient(cluster.getMetaIdentity())) {
        LogStream stream = client.createLog(LogName.of("testReadWrite"));
        LogWriter writer = stream.createWriter();
        String message = "Hello world!";
        ByteBuffer testMessage =  ByteBuffer.wrap(message.getBytes());
        writer.write(testMessage);
        LogReader reader = stream.createReader();
        ByteBuffer res = reader.readNext();
        assertEquals(message, ByteBufferUtils.toStringUtf8(res));
        // readNext() should return `null` when there is no remaining record
        res = reader.readNext();
        assertNull(res);
      }
    }

The above test test should either pass (or throw an exception on the second readNext() call), but hangs indefinitely. We should be able to catch this.

FYI vrodionov, rajeshbabu