Ralf Wildenhues wrote: > * Jim Meyering wrote on Sun, Sep 13, 2009 at 11:17:50AM CEST: >> Ralf Wildenhues wrote: >> > Jim Meyering writes: >> >> Here's post-7.6 NEWS so far: >> >> rm -r deletes deep hierarchies more efficiently. Before, it took >> >> O(N^2) >> >> time, now it takes O(N). >> > >> > What is N? The number of files removed, the number of directories removed, >> > the maximal subdirectory depth? > >> It's the latter, as implied by the preceding "deep hierarchies". > > Thanks. I suggest adding > , with N the subdirectory depth. > > to the NEWS entry. Still two lines, but much more precise now. :-)
alright, alright ;-) I've made a minor correction to the following entry, too: >From 21b617b78b5f53c1b6e1447f1709b1c2aa9f466f Mon Sep 17 00:00:00 2001 From: Jim Meyering <[email protected]> Date: Sun, 13 Sep 2009 11:48:03 +0200 Subject: [PATCH] doc: improve NEWS * NEWS (rm -r, without -f): Mention that the N in "O(N)" represents hierarchy depth. Suggested by Ralf Wildenhues. (rm -r, standards conformance): Make wording more accurate. --- NEWS | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/NEWS b/NEWS index b3c6c8c..ec41ca7 100644 --- a/NEWS +++ b/NEWS @@ -14,14 +14,14 @@ GNU coreutils NEWS -*- outline -*- cases, and slightly slower (20%) in at least one pathological case. rm -r deletes deep hierarchies more efficiently. Before, it took O(N^2) - time, now it takes O(N). However, this improvement is not as pronounced - as might be expected for very deep trees, because prior to this change, for - any relative name length longer than 8KiB, rm -r would sacrifice official - conformance to avoid the disproportionate O(N^2) performance penalty. - Leading to another improvement: + time, now it takes O(N), where N is the depth of the hierarchy. However, + this improvement is not as pronounced as might be expected for very + deep trees, because prior to this change, for any relative name length + longer than 8KiB, rm -r would sacrifice official conformance to avoid the + disproportionate O(N^2) performance penalty. Leading to another improvement: rm -r is now slightly more standards-conformant when operating on - write-protected relative file names longer than 8KiB. + write-protected files with relative names longer than 8KiB. * Noteworthy changes in release 7.6 (2009-09-11) [stable] -- 1.6.5.rc0.190.g15871
