tests/test-import-context.t

revsetbenchmarks: allow running multiple variants per revset

The current benchmarks were only testing the whole iteration. This is suboptimal
because some changes are meaningful for things like first result, minimum or
sorting.

We introduce a "variants" feature that let you systematically add some variants
to all revsets tested.

A typical variants value would be 'plain,min,last,sort'. When testing 'all()' it
will also provide testing for:
- all()
- min(all())
- last(all())
- sort(sort)

and output:

   plain         min            last           sort
0) 0.034568      0.037857       0.000074       0.034238
1) 0.011358  32% 0.020181  53%  0.000080 108%  0.011405  33%

Using revsets (who hit the API) instead of the internal API add some overhead,
but the overhead should be the same everywhere so it still allow comparison.
This is is more simple to implement and allows comparison with older versions
who do not have the same API.

Test applying context diffs

  $ cat > writepatterns.py <<EOF
  > import sys
  > 
  > path = sys.argv[1]
  > lasteol = sys.argv[2] == '1'
  > patterns = sys.argv[3:]
  > 
  > fp = file(path, 'wb')
  > for i, pattern in enumerate(patterns):
  >     count = int(pattern[0:-1])
  >     char = pattern[-1] + '\n'
  >     if not lasteol and i == len(patterns) - 1:
  >         fp.write((char*count)[:-1])
  >     else:
  >         fp.write(char*count)
  > fp.close()
  > EOF
  $ cat > cat.py <<EOF
  > import sys
  > sys.stdout.write(repr(file(sys.argv[1], 'rb').read()) + '\n')
  > EOF

Initialize the test repository

  $ hg init repo
  $ cd repo
  $ python ../writepatterns.py a 0 5A 1B 5C 1D
  $ python ../writepatterns.py b 1 1A 1B
  $ python ../writepatterns.py c 1 5A
  $ python ../writepatterns.py d 1 5A 1B
  $ hg add
  adding a
  adding b
  adding c
  adding d
  $ hg ci -m addfiles

Add file, missing a last end of line

  $ hg import --no-commit - <<EOF
  > *** /dev/null	2010-10-16 18:05:49.000000000 +0200
  > --- b/newnoeol	2010-10-16 18:23:26.000000000 +0200
  > ***************
  > *** 0 ****
  > --- 1,2 ----
  > + a
  > + b
  > \ No newline at end of file
  > *** a/a	Sat Oct 16 16:35:51 2010
  > --- b/a	Sat Oct 16 16:35:51 2010
  > ***************
  > *** 3,12 ****
  >   A
  >   A
  >   A
  > ! B
  >   C
  >   C
  >   C
  >   C
  >   C
  > ! D
  > \ No newline at end of file
  > --- 3,13 ----
  >   A
  >   A
  >   A
  > ! E
  >   C
  >   C
  >   C
  >   C
  >   C
  > ! F
  > ! F
  > 
  > *** a/b	2010-10-16 18:40:38.000000000 +0200
  > --- /dev/null	2010-10-16 18:05:49.000000000 +0200
  > ***************
  > *** 1,2 ****
  > - A
  > - B
  > --- 0 ----
  > *** a/c	Sat Oct 16 21:34:26 2010
  > --- b/c	Sat Oct 16 21:34:27 2010
  > ***************
  > *** 3,5 ****
  > --- 3,7 ----
  >   A
  >   A
  >   A
  > + B
  > + B
  > *** a/d	Sat Oct 16 21:47:20 2010
  > --- b/d	Sat Oct 16 21:47:22 2010
  > ***************
  > *** 2,6 ****
  >   A
  >   A
  >   A
  > - A
  > - B
  > --- 2,4 ----
  > EOF
  applying patch from stdin
  $ hg st
  M a
  M c
  M d
  A newnoeol
  R b

What's in a

  $ python ../cat.py a
  'A\nA\nA\nA\nA\nE\nC\nC\nC\nC\nC\nF\nF\n'
  $ python ../cat.py newnoeol
  'a\nb'
  $ python ../cat.py c
  'A\nA\nA\nA\nA\nB\nB\n'
  $ python ../cat.py d
  'A\nA\nA\nA\n'

  $ cd ..