revset: make use of natively-computed set for 'draft()' and 'secret()' If the computation of a set for each phase (done in C) is available, we use it directly instead of applying a simple filter. This give a massive speed-up in the vast majority of cases. On my mercurial repo with about 15000 out of 40000 draft changesets: revset: draft() plain min first last 0) 0.011201 0.019950 0.009844 0.000074 1) 0.000284 2% 0.000312 1% 0.000314 3% 0.000315 x4.3 Bad performance for "last" come from the handling of the 15000 elements set (memory allocation, filtering hidden changesets (99% of it) etc. compared to applying the filter only on a handfuld of revisions (the first draft changesets being close of tip). This is not seen as an issue since: * Timing is still pretty good and in line with all the other one, * Current user of Vanilla Mercurial will not have 1/3 of their repo draft, This bad effect disappears when phase's set is smaller. (about 200 secrets): revset: secret() plain min first last 0) 0.011181 0.022228 0.010851 0.000452 1) 0.000058 0% 0.000084 0% 0.000087 0% 0.000087 19%