Stefan Monnier <[EMAIL PROTECTED]> writes: >> How 'bout the patch below which makes no assumption (that I know of) about >> substitute-in-file-name, and will thus work correctly even with weird >> magic file name handlers. > > Regarding performance of my code: I just bumped into a performance > problem. The problem is that substitute-in-file-name can take a > non-negligible amount of time to execute when there's a "~user" in > the file name, because it calls getpwnam to figure out whether > "user" actually exists or not. > > At least here with 8K users in our YP database, my code causes > file-name-shadow-mode to take around 0.5-1s to refresh the screen > after each key stroke if there's a ~user in the file name I'm > editing.
You have seen Richard's proposal of going backwards linearly from the end and only checking at the "critical" characters like ~, / and $? It should also be possible to cache a piece of the last shadowing action and don't look again if no "critical" character has been added after the previous one in the nonshadowed section. But actually, I think my proposal about a C level interface into substitute-in-file-name would be most efficient, robust and unproblematic in the long run, and possibly useful for other applications as well. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum _______________________________________________ Emacs-devel mailing list Emacs-devel@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-devel
