view tests/test-committer.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

  $ unset HGUSER
  $ EMAIL="My Name <[e-mail]>"
  $ export EMAIL

  $ hg init test
  $ cd test
  $ touch asdf
  $ hg add asdf
  $ hg commit -m commit-1
  $ hg tip
  changeset:   0:53f268a58230
  tag:         tip
  user:        My Name <[e-mail]>
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-1
  

  $ unset EMAIL
  $ echo 1234 > asdf
  $ hg commit -u "[e-mail]" -m commit-1
  $ hg tip
  changeset:   1:3871b2a9e9bf
  tag:         tip
  user:        [e-mail]
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-1
  
  $ echo "[ui]" >> .hg/hgrc
  $ echo "username = foobar <[e-mail]>" >> .hg/hgrc
  $ echo 12 > asdf
  $ hg commit -m commit-1
  $ hg tip
  changeset:   2:8eeac6695c1c
  tag:         tip
  user:        foobar <[e-mail]>
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-1
  
  $ echo 1 > asdf
  $ hg commit -u "[e-mail]" -m commit-1
  $ hg tip
  changeset:   3:957606a725e4
  tag:         tip
  user:        [e-mail]
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-1
  
  $ echo 123 > asdf
  $ echo "[ui]" > .hg/hgrc
  $ echo "username = " >> .hg/hgrc
  $ hg commit -m commit-1
  abort: no username supplied
  (use 'hg config --edit' to set your username)
  [255]

# test alternate config var

  $ echo 1234 > asdf
  $ echo "[ui]" > .hg/hgrc
  $ echo "user = Foo Bar II <[e-mail]>" >> .hg/hgrc
  $ hg commit -m commit-1
  $ hg tip
  changeset:   4:6f24bfb4c617
  tag:         tip
  user:        Foo Bar II <[e-mail]>
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-1
  
# test prompt username

  $ cat > .hg/hgrc <<EOF
  > [ui]
  > askusername = True
  > EOF

  $ echo 12345 > asdf
  $ hg commit --config ui.interactive=False -m ask
  enter a commit username: 
  no username found, using '[^']*' instead (re)
  $ hg rollback -q

  $ hg commit --config ui.interactive=True -m ask <<EOF
  > Asked User <[e-mail]>
  > EOF
  enter a commit username: Asked User <[e-mail]>
  $ hg tip
  changeset:   5:84c91d963b70
  tag:         tip
  user:        Asked User <[e-mail]>
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     ask
  

# test no .hg/hgrc (uses generated non-interactive username)

  $ echo space > asdf
  $ rm .hg/hgrc
  $ hg commit -m commit-1 2>&1
  no username found, using '[^']*' instead (re)

  $ echo space2 > asdf
  $ hg commit -u ' ' -m commit-1
  transaction abort!
  rollback completed
  abort: empty username!
  [255]

# don't add tests here, previous test is unstable

  $ cd ..