Max Battcher <m...@worldmaker.net> writes: > It may be "revision 1782" to Trac, but 'show contents --match "hash > 2008..."' is "commute this file to how it would appear if only the > patches preceding or equal to this one with a timestamp from two years > ago were applied" to darcs. (Which ends up being quite possibly not a > "real" historic version at all [snip] Just for the record, this is completely wrong. This operation does no commutation at all. All it does is reconstruct the file as it was the instant after patch "2008..." was applied. The reason it is expensive is that obtaining the set of patches touching that file is O(n) in *repository* history (from 2008... to HEAD) , not in the *file* history.
This will eventually be fixed of course and does not need any DAG data (per Stephen), we just need a repository format that can get the set of primitive patches for a file in O(file_history) instead of O(repository_history). Benedikt's patchindex (formerly known as filecache) is a step in this direction, although it does not solve the problem completely. (What we get with that is O(file_history * biggest_patch_touching_the_file) kinda-sorta.) Of course, you could get down to O(logn) or even O(1) (in history size, it's not going below O(n) in file size, you see) if you stored more pristine copies of the file. But I guess we can look into that when we find out that the above is not enough. Yours, Petr. _______________________________________________ darcs-users mailing list darcs-users@darcs.net http://lists.osuosl.org/mailman/listinfo/darcs-users
