tests/test-serve.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

#require serve

  $ hgserve()
  > {
  >    hg serve -a localhost -d --pid-file=hg.pid -E errors.log -v $@ \
  >        | sed -e "s/:$HGPORT1\\([^0-9]\\)/:HGPORT1\1/g" \
  >              -e "s/:$HGPORT2\\([^0-9]\\)/:HGPORT2\1/g" \
  >              -e 's/http:\/\/[^/]*\//http:\/\/localhost\//'
  >    cat hg.pid >> "$DAEMON_PIDS"
  >    echo % errors
  >    cat errors.log
  >    killdaemons.py hg.pid
  > }

  $ hg init test
  $ cd test
  $ echo '[web]' > .hg/hgrc
  $ echo 'accesslog = access.log' >> .hg/hgrc
  $ echo "port = $HGPORT1" >> .hg/hgrc

Without -v

  $ hg serve -a localhost -p $HGPORT -d --pid-file=hg.pid -E errors.log
  $ cat hg.pid >> "$DAEMON_PIDS"
  $ if [ -f access.log ]; then
  >     echo 'access log created - .hg/hgrc respected'
  > fi
  access log created - .hg/hgrc respected

errors

  $ cat errors.log

With -v

  $ hgserve
  listening at http://localhost/ (bound to *$LOCALIP*:HGPORT1) (glob) (?)
  % errors

With -v and -p HGPORT2

  $ hgserve -p "$HGPORT2"
  listening at http://localhost/ (bound to *$LOCALIP*:HGPORT2) (glob) (?)
  % errors

With -v and -p daytime (should fail because low port)

#if no-root no-windows
  $ KILLQUIETLY=Y
  $ hgserve -p daytime
  abort: cannot start server at 'localhost:13': Permission denied
  abort: child process failed to start
  % errors
  $ KILLQUIETLY=N
#endif

With --prefix foo

  $ hgserve --prefix foo
  listening at http://localhost/foo/ (bound to *$LOCALIP*:HGPORT1) (glob) (?)
  % errors

With --prefix /foo

  $ hgserve --prefix /foo
  listening at http://localhost/foo/ (bound to *$LOCALIP*:HGPORT1) (glob) (?)
  % errors

With --prefix foo/

  $ hgserve --prefix foo/
  listening at http://localhost/foo/ (bound to *$LOCALIP*:HGPORT1) (glob) (?)
  % errors

With --prefix /foo/

  $ hgserve --prefix /foo/
  listening at http://localhost/foo/ (bound to *$LOCALIP*:HGPORT1) (glob) (?)
  % errors

  $ cd ..