Speed up the changes module

[GoogleCodeExporter]

It should be possible to slightly speed up analysis in the changes module by 
threading the operation and separating the git log in "chunks" of equal size 
distributed over all available cores.

/Adam Waldenberg

Original issue reported on code.google.com by [email protected] on 30 Jul 2013 at 12:57

[GoogleCodeExporter]

Original comment by [email protected] on 30 Jul 2013 at 1:15

• Changed state: Accepted

[GoogleCodeExporter]

Original comment by [email protected] on 24 Nov 2014 at 8:02

• Added labels: Milestone-Release0.4.1

[adam-waldenberg]

Some benchmarks shows the speed up achieved:

jquery repo before with -H ....................... 31.391s
jquery repo after with -H ........................ 28.558s

pango repo before with -H ........................ 27.749s
pango repo after with -H ......................... 20.703s

django repo before with -H ....................... 11m41.246s
django repo after with -H ........................ 08m37.141s

This is with the full analysis runing, including the blame output, which is consuming most of the elapsed time.