procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
$ hg init test
$ cd test
$ echo foo>foo
$ hg addremove
adding foo
$ hg commit -m "1"
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ hg clone . ../branch
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ../branch
$ hg co
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo bar>>foo
$ hg commit -m "2" -d '1 0'
$ cd ../test
$ hg pull ../branch
pulling from ../branch
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 84b9316f7b31
1 local changesets published
(run 'hg update' to get a working copy)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
$ hg co
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat foo
foo
bar
$ hg manifest --debug
6f4310b00b9a147241b071a60c28a650827fb03d 644 foo
update to rev 0 with a date
$ hg upd -d foo 0
abort: you can't specify a revision and a date
[10]
update by date
$ hg update -d '<1970-01-01 00:00:02 +0000'
found revision 1 from Thu Jan 01 00:00:01 1970 +0000
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg update -d '<1970-01-01 00:00:01 +0000'
found revision 1 from Thu Jan 01 00:00:01 1970 +0000
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg update -d '<1970-01-01 00:00:00 +0000'
found revision 0 from Thu Jan 01 00:00:00 1970 +0000
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg update -d '>1970-01-01 00:00:02 +0000'
abort: revision matching date not found
[10]
$ hg update -d '>1970-01-01 00:00:01 +0000'
found revision 1 from Thu Jan 01 00:00:01 1970 +0000
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg update -d '>1970-01-01 00:00:00 +0000'
found revision 1 from Thu Jan 01 00:00:01 1970 +0000
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
update to default destination (with empty revspec)
$ hg update -q null
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg id
84b9316f7b31 tip
$ hg update -q null
$ hg update -r ''
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg id
84b9316f7b31 tip
$ hg update -q null
$ hg update ''
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg id
84b9316f7b31 tip
$ cd ..
update with worker processes
#if no-windows
$ cat <<EOF > forceworker.py
> from mercurial import extensions, worker
> def nocost(orig, ui, costperop, nops, threadsafe=True):
> return worker._numworkers(ui) > 1
> def uisetup(ui):
> extensions.wrapfunction(worker, 'worthwhile', nocost)
> EOF
$ hg init worker
$ cd worker
$ cat <<EOF >> .hg/hgrc
> [extensions]
> forceworker = $TESTTMP/forceworker.py
> [worker]
> numcpus = 4
> EOF
$ for i in `"$PYTHON" $TESTDIR/seq.py 1 100`; do
> echo $i > $i
> done
$ hg ci -qAm 'add 100 files'
$ hg update null
0 files updated, 0 files merged, 100 files removed, 0 files unresolved
$ hg update -v | grep 100
getting 100
100 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg status
$ cd ..
#endif