view tests/test-logtoprocess.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

#require no-windows

ATTENTION: logtoprocess runs commands asynchronously. Be sure to append "| cat"
to hg commands, to wait for the output, if you want to test its output.
Otherwise the test will be flaky.

Test if logtoprocess correctly captures command-related log calls.

  $ hg init
  $ cat > $TESTTMP/foocommand.py << EOF
  > from __future__ import absolute_import
  > from mercurial import registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > configtable = {}
  > configitem = registrar.configitem(configtable)
  > configitem(b'logtoprocess', b'foo',
  >     default=None,
  > )
  > @command(b'foobar', [])
  > def foo(ui, repo):
  >     ui.log(b'foo', b'a message: %s\n', b'spam')
  > EOF
  $ cp $HGRCPATH $HGRCPATH.bak
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > logtoprocess=
  > foocommand=$TESTTMP/foocommand.py
  > [logtoprocess]
  > command=(echo 'logtoprocess command output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1") > $TESTTMP/command.log
  > commandfinish=(echo 'logtoprocess commandfinish output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1";
  >     echo "canonical: \$OPT_CANONICAL_COMMAND") > $TESTTMP/commandfinish.log
  > foo=(echo 'logtoprocess foo output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1") > $TESTTMP/foo.log
  > EOF

Running a command triggers both a ui.log('command') and a
ui.log('commandfinish') call. The foo command also uses ui.log.

Use sort to avoid ordering issues between the various processes we spawn:
  $ hg fooba
  $ sleep 1
  $ cat $TESTTMP/command.log | sort
  
  command
  fooba
  logtoprocess command output:

#if no-chg
  $ cat $TESTTMP/commandfinish.log | sort
  
  canonical: foobar
  commandfinish
  fooba exited 0 after * seconds (glob)
  logtoprocess commandfinish output:
  $ cat $TESTTMP/foo.log | sort
  
  a message: spam
  foo
  logtoprocess foo output:
#endif

Confirm that logging blocked time catches stdio properly:
  $ cp $HGRCPATH.bak $HGRCPATH
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > logtoprocess=
  > pager=
  > [logtoprocess]
  > uiblocked=echo "\$EVENT stdio \$OPT_STDIO_BLOCKED ms command \$OPT_COMMAND_DURATION ms" > $TESTTMP/uiblocked.log
  > [ui]
  > logblockedtimes=True
  > EOF

  $ hg log
  $ sleep 1
  $ cat $TESTTMP/uiblocked.log
  uiblocked stdio [0-9]+.[0-9]* ms command [0-9]+.[0-9]* ms (re)

Try to confirm that pager wait on logtoprocess:

Add a script that wait on a file to appears for 5 seconds, if it sees it touch
another file or die after 5 seconds. If the scripts is awaited by hg, the
script will die after the timeout before we could touch the file and the
resulting file will not exists. If not, we will touch the file and see it.

  $ cat >> fakepager.py <<EOF
  > import sys
  > printed = False
  > for line in sys.stdin:
  >     sys.stdout.write(line)
  >     printed = True
  > if not printed:
  >     sys.stdout.write('paged empty output!\n')
  > EOF

  $ cat > $TESTTMP/wait-output.sh << EOF
  > #!/bin/sh
  > for i in \`$TESTDIR/seq.py 50\`; do
  >   if [ -f "$TESTTMP/wait-for-touched" ];
  >   then
  >     touch "$TESTTMP/touched";
  >     break;
  >   else
  >     sleep 0.1;
  >   fi
  > done
  > EOF
  $ chmod +x $TESTTMP/wait-output.sh

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > logtoprocess=
  > pager=
  > [pager]
  > pager = "$PYTHON" $TESTTMP/fakepager.py
  > [logtoprocess]
  > commandfinish=$TESTTMP/wait-output.sh
  > EOF
  $ hg version -q --pager=always
  Mercurial Distributed SCM (version *) (glob)
  $ touch $TESTTMP/wait-for-touched
  $ sleep 0.2
  $ test -f $TESTTMP/touched && echo "SUCCESS Pager is not waiting on ltp" || echo "FAIL Pager is waiting on ltp"
  SUCCESS Pager is not waiting on ltp