Slow to execute over diffs with a large number of changes

[termi]

In some cases JsDiff.diffWords ate more than 500Mb RAM and I had to kill the process where it was launched

I found this in node.js environment but it also produced in browser.

Data for reproducing this bug is here: https://gist.github.com/termi/9875658

[KiNgMaR]

Hi @kpdecker, have you had any chance to look into this? I'm seeing the same issue with createPatch and two text files. Thanks!

[kpdecker]

Any diffing algorithm is going to take time when presented with a lot of options and particularly when those options are very different.

I was able to dramatically improve the runtime of this test case though, dropping the exec time from 18min to 2min on my local machine. The memory use also dropped from GBs to 200-300MB (All of these times are from exec within a Node environment)

There might be some remaining minor optimizations that are available, but short of changing the algorithm or diffing a smaller set of data such as lines, there aren't many alternatives for massive improvement, I fear.

[kpdecker]

Released in 1.2.0