private DBCursor oplogCursor(final Timestamp<?> timestampOverride) throws SlurperException {
Timestamp<?> time =
timestampOverride == null
? MongoDBRiver.getLastTimestamp(client, definition)
: timestampOverride;
DBObject indexFilter = time.getOplogFilter();
if (indexFilter == null) {
return null;
}
int options =
Bytes.QUERYOPTION_TAILABLE | Bytes.QUERYOPTION_AWAITDATA | Bytes.QUERYOPTION_NOTIMEOUT;
// Using OPLOGREPLAY to improve performance:
// https://jira.mongodb.org/browse/JAVA-771
if (indexFilter.containsField(MongoDBRiver.OPLOG_TIMESTAMP)) {
options = options | Bytes.QUERYOPTION_OPLOGREPLAY;
}
DBCursor cursor = oplogCollection.find(indexFilter).setOptions(options);
isRiverStale(cursor, time);
return cursor;
}
protected boolean isIndexEmpty() {
return MongoDBRiver.getIndexCount(client, definition) == 0;
}
protected boolean riverHasIndexedFromOplog() {
return MongoDBRiver.getLastTimestamp(client, definition) != null;
}
