tests/test-debugextensions.t

revset: optimize "draft() & ::x" pattern

The `draft() & ::x` type query could be common for selecting one or more
draft feature branches being worked on.

Before this patch, `::x` may travel through the changelog DAG for a long
distance until it gets a smaller revision number than `min(draft())`. It
could be very slow on long changelog with distant (in terms of revision
numbers) drafts.

This patch adds a fast path for this situation, and will stop traveling the
changelog DAG once `::x` hits a non-draft revision.

The fast path also works for `secret()` and `not public()`.

To measure the performance difference, I used drawdag to create a repo that
emulates distant drafts:

          DRAFT4
           |
          DRAFT3 # draft
          /
  PUBLIC9999 # public
      |
  PUBLIC9998
      |
      .   DRAFT2
      .    |
      .   DRAFT1 # draft
      |   /
  PUBLIC0001 # public

And measured the performance using the repo:

  (BEFORE)
  $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
  ! wall 0.017132 comb 0.010000 user 0.010000 sys 0.000000 (best of 156)
  $ hg perfrevset 'draft() & ::(all())'
  ! wall 0.024221 comb 0.030000 user 0.030000 sys 0.000000 (best of 113)
  (AFTER)
  $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
  ! wall 0.000243 comb 0.000000 user 0.000000 sys 0.000000 (best of 9303)
  $ hg perfrevset 'draft() & ::(all())'
  ! wall 0.004319 comb 0.000000 user 0.000000 sys 0.000000 (best of 655)

Differential Revision: https://phab.mercurial-scm.org/D441

  $ hg debugextensions

  $ debugpath=`pwd`/extwithoutinfos.py

  $ cat > extwithoutinfos.py <<EOF
  > EOF
  $ cat > extwithinfos.py <<EOF
  > testedwith = '3.0 3.1 3.2.1'
  > buglink = 'https://example.org/bts'
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > patchbomb=
  > rebase=
  > mq=
  > ext1 = $debugpath
  > ext2 = `pwd`/extwithinfos.py
  > EOF

  $ hg debugextensions
  ext1 (untested!)
  ext2 (3.2.1!)
  histedit
  mq
  patchbomb
  rebase

  $ hg debugextensions -v
  ext1
    location: */extwithoutinfos.py* (glob)
    bundled: no
  ext2
    location: */extwithinfos.py* (glob)
    bundled: no
    tested with: 3.0 3.1 3.2.1
    bug reporting: https://example.org/bts
  histedit
    location: */hgext/histedit.py* (glob)
    bundled: yes
  mq
    location: */hgext/mq.py* (glob)
    bundled: yes
  patchbomb
    location: */hgext/patchbomb.py* (glob)
    bundled: yes
  rebase
    location: */hgext/rebase.py* (glob)
    bundled: yes

  $ hg debugextensions -Tjson | sed 's|\\\\|/|g'
  [
   {
    "buglink": "",
    "bundled": false,
    "name": "ext1",
    "source": "*/extwithoutinfos.py*", (glob)
    "testedwith": []
   },
   {
    "buglink": "https://example.org/bts",
    "bundled": false,
    "name": "ext2",
    "source": "*/extwithinfos.py*", (glob)
    "testedwith": ["3.0", "3.1", "3.2.1"]
   },
   {
    "buglink": "",
    "bundled": true,
    "name": "histedit",
    "source": "*/hgext/histedit.py*", (glob)
    "testedwith": []
   },
   {
    "buglink": "",
    "bundled": true,
    "name": "mq",
    "source": "*/hgext/mq.py*", (glob)
    "testedwith": []
   },
   {
    "buglink": "",
    "bundled": true,
    "name": "patchbomb",
    "source": "*/hgext/patchbomb.py*", (glob)
    "testedwith": []
   },
   {
    "buglink": "",
    "bundled": true,
    "name": "rebase",
    "source": "*/hgext/rebase.py*", (glob)
    "testedwith": []
   }
  ]

  $ hg debugextensions -T '{ifcontains("3.1", testedwith, "{name}\n")}'
  ext2
  $ hg debugextensions \
  > -T '{ifcontains("3.2", testedwith, "no substring match: {name}\n")}'