Latest data point not plotted after a disconnect #2727
Merged
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An issue was introduced in #2713 where we attempted to show PV disconnections in the data browser. In the current implementation we attempt to detect a 'disconnect' messages in the metadata of a data item and add an extra data point to signal this. On the following
next()
call to the iterator it uses the previous message (which was just replaced with the disconnect) to make sure no data is missed.It turns out there is a particular case that causes a problem when it is the final message from the archiver that contains the disconnect. What this means is that now the
next()
function never gets called as the iterator is empty (sohasNext()
returnsfalse
) and so we can miss the following (i.e. latest) value. This means that the value after the last disconnect does not get plotted.This PR contains a fix for this where I have updated the
hasNext()
method of the iterator to returntrue
if we still need to process the most recent message (meaning thatnext()
will be called one final time).