Hi, On Wed, 23 Apr 2008, Avery Pennarun wrote: > From: Jeff King <peff@xxxxxxxx> > > On Tue, Apr 22, 2008 at 12:51:14PM -0400, Avery Pennarun wrote: > > > Do you think git would benefit from having a generalized version of > > this script? Basically, the user provides a "munge" script on the > > command line, and there's a git-filter-branch mode for auto-munging > > (with a cache) every file in every checkin. Even if it's *only* ever > > used for CRLF, I can imagine this being useful to a lot of people. > > It was easy enough to work up the patch below, which allows > > git filter-branch --blob-filter 'tr a-z A-Z' > > However, it's _still_ horribly slow. Shell script is nice and flexible, > but running a tight loop like this is just painful. I suspect > filter-branch in something like perl would be a lot faster and just as > flexible (you could even do it in C, but you'd probably have to invent a > little domain-specific scripting language). > > It is still much better performance than a tree filter, though: > > $ cd git && time git filter-branch --tree-filter ' > find . -type f | while read f; do > tr a-z A-Z <"$f" >tmp > mv tmp "$f" > done > ' HEAD~10..HEAD > > real 4m38.626s > user 1m32.726s > sys 2m51.163s > > $ cd git && git filter-branch --blob-filter 'tr a-z A-Z' HEAD~10..HEAD > real 1m40.809s > user 0m36.822s > sys 1m14.273s > > Lots of system time in both. I'm sure we spend a fair bit of time > hitting our very large map and blob-cache directories, which would be > much more nicely implemented as associative arrays in memory (if we were > using a more featureful language). > > Anyway, here is the patch. I don't know if it is even worth applying, > since it is still painfully slow. Not all of this belongs in the commit messaage. > Acked-by: Johannes Schindelin <johannes.schindelin@xxxxxx> This does. A good general rule is: if you think it would be funny/strange to read this message in the output of "git log", it should be changed. Ciao, Dscho -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
