reachableroots: default to the C implementation
This patch is part of a series of patches to speed up the computation of
revset.reachableroots by introducing a C implementation. The main motivation is to
speed up smartlog on big repositories. At the end of the series, on our big
repositories the computation of reachableroots is 10-50x faster and smartlog on is
2x-5x faster.
Before this patch, reachableroots was computed in pure Python by default. This
patch makes the C implementation the default and provides a speedup for
reachableroots.
% lazy ancestor set for [], stoprev = 0, inclusive = False
membership: []
iteration: []
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = False
membership: [7, 8, 3, 4, 1, 0]
iteration: [3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [1, 3], stoprev = 0, inclusive = False
membership: [1, 0]
iteration: [0, 1]
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = True
membership: [11, 13, 7, 8, 3, 4, 1, 0]
iteration: [11, 13, 3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = False
membership: [7, 8]
iteration: [7, 8]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = True
membership: [11, 13, 7, 8]
iteration: [11, 13, 7, 8]