view tests/test-logtoprocess.t @ 49000:dd6b67d5c256 stable

rust: fix unsound `OwningDirstateMap`

As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.

The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.

I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.

In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.

Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.

Differential Revision: https://phab.mercurial-scm.org/D12429

#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