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.
test --time
$ hg --time help -q help 2>&1 | grep time > /dev/null
$ hg init a
$ cd a
Function to check that statprof ran
$ statprofran () {
> egrep 'Sample count:|No samples recorded' > /dev/null
> }
test --profile
$ hg st --profile 2>&1 | statprofran
Abreviated version
$ hg st --prof 2>&1 | statprofran
In alias
$ hg --config "alias.profst=status --profile" profst 2>&1 | statprofran
#if lsprof
$ prof () {
> hg --config profiling.type=ls --profile $@
> }
$ prof st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ prof --config profiling.output=../out st
$ grep CallCount ../out > /dev/null || cat ../out
$ prof --config profiling.output=blackbox --config extensions.blackbox= st
$ grep CallCount .hg/blackbox.log > /dev/null || cat .hg/blackbox.log
$ prof --config profiling.format=text st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ echo "[profiling]" >> $HGRCPATH
$ echo "format=kcachegrind" >> $HGRCPATH
$ prof st 2>../out
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
$ prof --config profiling.output=../out st
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
#endif
#if lsprof serve
Profiling of HTTP requests works
$ prof --config profiling.format=text --config profiling.output=../profile.log serve -d -p $HGPORT --pid-file ../hg.pid -A ../access.log
$ cat ../hg.pid >> $DAEMON_PIDS
$ hg -q clone -U http://localhost:$HGPORT ../clone
A single profile is logged because file logging doesn't append
$ grep CallCount ../profile.log | wc -l
\s*1 (re)
#endif
Install an extension that can sleep and guarantee a profiler has time to run
$ cat >> sleepext_with_a_long_filename.py << EOF
> import time
> from mercurial import registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'sleep', [], b'hg sleep')
> def sleep_for_at_least_one_stat_cycle(ui, *args, **kwargs):
> t = time.time() # don't use time.sleep because we need CPU time
> while time.time() - t < 0.5:
> pass
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> sleep = `pwd`/sleepext_with_a_long_filename.py
> EOF
statistical profiler works
$ hg --profile sleep 2>../out
$ cat ../out | statprofran
Various statprof formatters work
$ hg --profile --config profiling.statformat=byline sleep 2>../out || cat ../out
$ grep -v _path_stat ../out | head -n 3
% cumulative self
time seconds seconds name
* sleepext_with_a_long_filename.py:*:sleep_for_at_least_one_stat_cycle (glob)
$ cat ../out | statprofran
$ hg --profile --config profiling.statformat=bymethod sleep 2>../out || cat ../out
$ head -n 1 ../out
% cumulative self
$ cat ../out | statprofran
Windows real time tracking is broken, only use CPU
#if no-windows
$ hg --profile --config profiling.time-track=real --config profiling.statformat=hotpath sleep 2>../out || cat ../out
$ cat ../out | statprofran
$ grep sleepext_with_a_long_filename.py ../out | head -n 1
.* [0-9.]+% [0-9.]+s sleepext_with_a_long_filename.py:\s*sleep_for_at_least_one_stat_cycle, line \d+:\s+(while|pass).* (re)
#endif
$ hg --profile --config profiling.time-track=cpu --config profiling.statformat=hotpath sleep 2>../out || cat ../out
$ cat ../out | statprofran
$ grep sleepext_with_a_long_filename.py ../out | head -n 1
.* [0-9.]+% [0-9.]+s sleepext_with_a_long_filename.py:\s*sleep_for_at_least_one_stat_cycle, line \d+:\s+(while|pass).* (re)
$ hg --profile --config profiling.statformat=json sleep 2>../out || cat ../out
$ cat ../out
\[\[-?\d+.* (re)
statprof can be used as a standalone module
$ "$PYTHON" -m mercurial.statprof hotpath
must specify --file to load
[1]
$ cd ..
#if no-chg
profiler extension could be loaded before other extensions
$ cat > fooprof.py <<EOF
> import contextlib
> import sys
> @contextlib.contextmanager
> def profile(ui, fp):
> print('fooprof: start profile')
> sys.stdout.flush()
> yield
> print('fooprof: end profile')
> sys.stdout.flush()
> def extsetup(ui):
> ui.write(b'fooprof: loaded\n')
> EOF
$ cat > otherextension.py <<EOF
> def extsetup(ui):
> ui.write(b'otherextension: loaded\n')
> EOF
$ hg init b
$ cd b
$ cat >> .hg/hgrc <<EOF
> [extensions]
> other = $TESTTMP/otherextension.py
> fooprof = $TESTTMP/fooprof.py
> EOF
$ hg root
otherextension: loaded
fooprof: loaded
$TESTTMP/b
$ HGPROF=fooprof hg root --profile
fooprof: loaded
fooprof: start profile
otherextension: loaded
$TESTTMP/b
fooprof: end profile
$ HGPROF=other hg root --profile 2>&1 | head -n 2
otherextension: loaded
unrecognized profiler 'other' - ignored
$ HGPROF=unknown hg root --profile 2>&1 | head -n 1
unrecognized profiler 'unknown' - ignored
$ cd ..
#endif