@Test
public void whenBlock_whenNoSpace() {
for (int k = 0; k < ringbuffer.capacity(); k++) {
topic.publish("old");
}
final long tail = ringbuffer.tailSequence();
final long head = ringbuffer.headSequence();
// add the item
final Future f =
spawn(
new Runnable() {
@Override
public void run() {
topic.publish("new");
}
});
assertTrueAllTheTime(
new AssertTask() {
@Override
public void run() throws Exception {
assertFalse(f.isDone());
assertEquals(tail, ringbuffer.tailSequence());
assertEquals(head, ringbuffer.headSequence());
}
},
5);
// assert that message is published eventually
assertCompletesEventually(f);
}
public static void main(String[] args) throws Exception {
HazelcastInstance hz = Hazelcast.newHazelcastInstance();
Ringbuffer<Long> rb = hz.getRingbuffer("rb");
// we start from the oldest item.
// if you want to start from the next item, call rb.tailSequence()+1
long sequence = rb.headSequence();
System.out.println("Start reading from: " + sequence);
while (true) {
long item = rb.readOne(sequence);
sequence++;
System.out.println("Read: " + item);
}
}
@Test
public void whenDiscardOldest_whenNoSpace() {
for (int k = 0; k < ringbuffer.capacity(); k++) {
topic.publish("old");
}
long tail = ringbuffer.tailSequence();
long head = ringbuffer.headSequence();
topic.publish("new");
// check that an item has been added
assertEquals(tail + 1, ringbuffer.tailSequence());
assertEquals(head + 1, ringbuffer.headSequence());
}
@Test
public void whenDiscardNewest_whenNoSpace() {
for (int k = 0; k < ringbuffer.capacity(); k++) {
topic.publish("old");
}
long tail = ringbuffer.tailSequence();
long head = ringbuffer.headSequence();
topic.publish("new");
// check that nothing has changed
assertEquals(tail, ringbuffer.tailSequence());
assertEquals(head, ringbuffer.headSequence());
}
@Test
public void test_whenSpace() throws Exception {
topic.publish("foo");
ReliableTopicMessage msg = ringbuffer.readOne(0);
assertEquals("foo", serializationService.toObject(msg.getPayload()));
}
@Test
public void whenError_andNoSpace() {
for (int k = 0; k < ringbuffer.capacity(); k++) {
topic.publish("old");
}
long tail = ringbuffer.tailSequence();
long head = ringbuffer.headSequence();
try {
topic.publish("new");
fail();
} catch (TopicOverloadException expected) {
EmptyStatement.ignore(expected);
}
assertEquals(tail, ringbuffer.tailSequence());
assertEquals(head, ringbuffer.headSequence());
}
@Test
public void whenBlock_whenNoSpace() {
for (int k = 0; k < ringbuffer.capacity(); k++) {
topic.publish("old");
}
final long tail = ringbuffer.tailSequence();
final long head = ringbuffer.headSequence();
// add the item
final Future f =
spawn(
new Runnable() {
@Override
public void run() {
topic.publish("new");
}
});
// make sure it doesn't complete within 3 seconds. We have a 2 second error margin to prevent
// spurious test failures
assertTrueAllTheTime(
new AssertTask() {
@Override
public void run() throws Exception {
assertFalse(f.isDone());
assertEquals(tail, ringbuffer.tailSequence());
assertEquals(head, ringbuffer.headSequence());
}
},
3);
assertCompletesEventually(f);
assertEquals(tail + 1, ringbuffer.tailSequence());
// since the ringbuffer got cleaned, the head is at the tail
assertEquals(tail + 1, ringbuffer.headSequence());
}