The command hg log --template "{bookmarks}" runs very slowly on repositories with large numbers of bookmarks and revisions. For each revision, the "{bookmarks}" template iterates over every bookmark, picking out the ones that match the revision, doing a total of O(number of revisions * number of bookmarks) work. It seems like it should be possible to reduce this to O(number of revisions + number of bookmarks) by computing a mapping from revisions to bookmarks and reusing that for each revision.
Fixed by https://mercurial-scm.org/repo/hg/rev/04ceb267271a Yuya Nishihara <yuya@tcha.org> bookmarks: cache reverse mapping (issue5868) I chose a simpler implementation. If the initial cost of building reverse mapping is significant, we'll have to move it under @propertycache. The nodemap could be a dict of sets, but I think keeping a sorted list is better since each node is likely to have zero/one bookmark. Micro-benchmark with 1001 bookmarks and 1001 revisions: $ for n in `seq 0 1000`; do touch $n; hg book book$n; hg ci -qAm$n; done $ hg bookmarks --time > /dev/null (orig) time: real 0.040 secs (user 0.050+0.000 sys 0.000+0.000) (new) time: real 0.040 secs (user 0.040+0.000 sys 0.010+0.000) $ hg log -T '{bookmarks}\n' --time > /dev/null (orig) time: real 0.160 secs (user 0.160+0.000 sys 0.000+0.000) (new) time: real 0.090 secs (user 0.100+0.000 sys 0.000+0.000) (please test the fix)
I've tested revision 04ceb267271a, and it does resolve the problem. Thank you!