view tests/test-issue4074.t @ 33003:f63d111258da

revset: add startdepth limit to ancestors() as internal option

This is necessary to implement the set{gen} (set subscript) operator. For
example, set{-n} will be translated to ancestors(set, depth=n, startdepth=n).

https://www.mercurial-scm.org/wiki/RevsetOperatorPlan#ideas_from_mpm

The UI is undecided and I doubt if the startdepth option would be actually
useful, so the option is hidden for now. 'depth' could be extended to take
min:max range, in which case, integer depth should select a single generation.

  ancestors(set, depth=:y)  # scan up to y-th generation
  ancestors(set, depth=x:)  # skip until (x-1)-th generation
  ancestors(set, depth=x)   # select only x-th generation

Any ideas are welcomed.

  # reverse(ancestors(tip)) using hg repo
  3) 0.075951
  4) 0.076175

#require no-pure

A script to generate nasty diff worst-case scenarios:

  $ cat > s.py <<EOF
  > import random
  > for x in xrange(100000):
  >     print
  >     if random.randint(0, 100) >= 50:
  >         x += 1
  >     print hex(x)
  > EOF

  $ hg init a
  $ cd a

Check in a big file:

  $ $PYTHON ../s.py > a
  $ hg ci -qAm0

Modify it:

  $ $PYTHON ../s.py > a

Time a check-in, should never take more than 10 seconds user time:

  $ hg ci --time -m1
  time: real .* secs .user [0-9][.].* sys .* (re)