Hi, On Wed, 7 Jan 2009, Davide Libenzi wrote: > On Wed, 7 Jan 2009, Johannes Schindelin wrote: > > > Could it be that you misread my patch, and assumed that I faked an > > xdfenv? > > > > I did not, but instead faked two mmfiles, which is only as simple as I did > > it because in git.git, we only have contiguous mmfiles. (I recall that > > libxdiff allows for ropes instead of arrays.) > > > > The way I did it has one big shortcoming: I need to prepare an xdfenv for > > the subfiles even if I already prepared one for the complete files. IOW > > the lines are rehashed all over again. > > I told you I just glanced at the code :) > In that way, if you guys decide to merge this new algo, you'll need to > split the prepare from the optimize, and feed it with an already prepared > env. Right. > Before going that way, have you ever tried to tweak xdl_cleanup_records > and xdl_clean_mmatch to reduce the level of optimization, and see the > results you get? It is possible that you won't need two different algos > inside git. No, I hadn't thought that libxdiff already determines uniqueness before actually running xdl_do_diff(). I also have to admit that I am not as clever as other people, and had quite a hard time figuring out as much as I did (for example, that rchg[i] == 1 means that this line is to be added/deleted, and that i is in the range 0, ..., N - 1 rather than 1, ..., N). So it is quite possible that something patience-like can be done earlier. However, I do not see a way to implement the recursion necessary for the patience diff. Remember: patience(line range): find unique lines if no unique lines found: resort to classical diff return extract the longest common sequence of unique common lines between those, recurse When recursing, previously non-unique lines can turn unique, of course. And I do not see how that recursion could be done before xdl_clean_mmatch(), short of redoing the hashing and cleaning records up. Of course, it might well be possible, but I am already out of my depth reading something like "rdis0" and "rpdis1", and being close to despair. :') 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
