[AMIEQueue] Add progress bar for each generation

[falcaopetri]

This PR modifies the AMIEQueue such that it reports the mining progress using a progress bar (if -verbose).
I've used the most active Java CLI progress bar I cound find (https://github.com/ctongfei/progressbar).

One (minor?) issue is that AMIE's logging conflicts with the line breaks, yielding some lines with both progressbar and AMIE logging. I think the only solution would be to use some logging module and redirect the different output types to different files.

I've also used a heuristic to set how often the progress bar should be updated. It seems to work on my small experiments, but I will still test it with bigger datasets.

I'm not sure yet about the overhead added by this (i) if verbose is not set, (ii) if verbose is set.

[falcaopetri]

Note that I've implemented the Progress Bar to update during AMIEQueue.dequeue. This means that the progress bar can reach 100%, while we still have rules being processed. In that case, the timer will continue to advance.

I did not realize that at implementation time. My consideration was only that:

• Only AMIEQueue knows about the next generation (and I wanted one progress bar for each generation)
• AMIEQueue.dequeue is already synchronized between all workers

An alternative implementation would move the responsibility of the ProgressBar to AMIE. This would require adding a lock (which is easy to do). This way, we would reach 100% only after processing all available rules.

[lajus]

Hi,

I like the idea of the progress bar. I also think AMIEQueue.dequeue is the place to do that.

As for the 100% progress problem, the number of processed rules should always be equal to: "number of dequeues" - "number of active threads" and this last number is always equal to maxThreads - waitingThreads if I am correct.

Jonathan