Performance: use clipped polygon to draw lines

[nigelzor]

Filled polygon statistics are only drawn in the currently-visible region. Line statistics can re-use this logic, rather than wastefully drawing to areas scrolled out of view.

When working with large GC log files, this is a major performance improvement.

[chewiebug]

Hi Neil,

Thank you for contributing this improvement! I found that GCRectanglesRenderer didn't use any clipping logic as well. I have added another fix for that renderer.

By the way: How large are "large" log files for you? How many gc events do they contain?

Regards, Jörg

[nigelzor]

The application I was looking at had ~350 GC events per minute. A 2-hour log (6 MB) made GCViewer unresponsive and very difficult to scroll.

After these changes, I've looked at 200,000-event log files with no difficulty.

[vlsi]

You rock!
My 28MiB gc log with 200K events renders with no problems.

[chewiebug]

Neil - thank you again for contributing! I am happy to see that the patch helps.

Would one of you be willing to send me a large log file to [email protected] or using http://www.fileconvoy.com/index.php? I'd like to have one for later regression testing.

Regards, Jörg