private List<GridEvent> getNextSlice(long elapsed) {
List<GridEvent> slice = new ArrayList<GridEvent>();
if (elapsed <= 0) return slice;
this.totalElapsed += elapsed;
log.trace("getNextSlice, prevElapsed={}, totalElapsed={}", prevElapsed, totalElapsed);
if (prevElapsed >= totalElapsed) {
log.warn(
"No slice possible with (prevElapsed={}, totalElapsed={})", prevElapsed, totalElapsed);
return slice;
}
long start = prevElapsed;
long end = totalElapsed;
SortedMap<Long, List<Event>> eventSlice = timeline.getEvents(start, end);
if (!eventSlice.isEmpty()) {
// We only move the start of the window up when we find an event. This done because the
// database might
// have gaps if the incoming events cannot be processed in real-time. In that case, we don't
// want to
// miss any events if they come late.
this.prevElapsed = totalElapsed;
log.trace("Timeline has {} offset buckets", timeline.getNumOffsets());
log.info(
"Requested slice where {}<=t<{} and got " + eventSlice.size() + " buckets", start, end);
}
if (!eventSlice.isEmpty()) {
for (Long offset : eventSlice.keySet()) {
log.trace("Got offset bucket {}", offset);
if (offset >= totalElapsed) {
log.warn(
"Timeline returned grid events outside the requested frame: {}>{}",
offset,
totalElapsed);
break;
}
List<Event> events = eventSlice.get(offset);
synchronized (events) {
if (events.isEmpty()) {
log.trace("Got empty offset bucket for offset {}", offset);
}
for (Event event : events) {
if (event instanceof GridEvent) {
GridEvent gridEvent = (GridEvent) event;
log.trace("Got grid event {}", gridEvent);
slice.add(gridEvent);
} else if (event instanceof SnapshotEvent) {
SnapshotEvent gridEvent = (SnapshotEvent) event;
log.trace("Got snapshot event {}", gridEvent);
} else {
log.trace("Got unrecognized event {}", event);
}
}
}
}
}
return slice;
}
