push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
#!/usr/bin/env python3
# fsmonitor-run-tests.py - Run Mercurial tests with fsmonitor enabled
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# This is a wrapper around run-tests.py that spins up an isolated instance of
# Watchman and runs the Mercurial tests against it. This ensures that the global
# version of Watchman isn't affected by anything this test does.
import argparse
import contextlib
import json
import os
import shutil
import subprocess
import sys
import tempfile
import uuid
osenvironb = getattr(os, 'environb', os.environ)
if sys.version_info > (3, 5, 0):
PYTHON3 = True
def _sys2bytes(p):
return p.encode('utf-8')
elif sys.version_info >= (3, 0, 0):
print(
'%s is only supported on Python 3.5+ and 2.7, not %s'
% (sys.argv[0], '.'.join(str(v) for v in sys.version_info[:3]))
)
sys.exit(70) # EX_SOFTWARE from `man 3 sysexit`
else:
PYTHON3 = False
# In python 2.x, path operations are generally done using
# bytestrings by default, so we don't have to do any extra
# fiddling there. We define the wrapper functions anyway just to
# help keep code consistent between platforms.
def _sys2bytes(p):
return p
def getparser():
"""Obtain the argument parser used by the CLI."""
parser = argparse.ArgumentParser(
description='Run tests with fsmonitor enabled.',
epilog='Unrecognized options are passed to run-tests.py.',
)
# - keep these sorted
# - none of these options should conflict with any in run-tests.py
parser.add_argument(
'--keep-fsmonitor-tmpdir',
action='store_true',
help='keep temporary directory with fsmonitor state',
)
parser.add_argument(
'--watchman',
help='location of watchman binary (default: watchman in PATH)',
default='watchman',
)
return parser
@contextlib.contextmanager
def watchman(args):
basedir = tempfile.mkdtemp(prefix='hg-fsmonitor')
try:
# Much of this configuration is borrowed from Watchman's test harness.
cfgfile = os.path.join(basedir, 'config.json')
# TODO: allow setting a config
with open(cfgfile, 'w') as f:
f.write(json.dumps({}))
logfile = os.path.join(basedir, 'log')
clilogfile = os.path.join(basedir, 'cli-log')
if os.name == 'nt':
sockfile = '\\\\.\\pipe\\watchman-test-%s' % uuid.uuid4().hex
else:
sockfile = os.path.join(basedir, 'sock')
pidfile = os.path.join(basedir, 'pid')
statefile = os.path.join(basedir, 'state')
argv = [
args.watchman,
'--sockname',
sockfile,
'--logfile',
logfile,
'--pidfile',
pidfile,
'--statefile',
statefile,
'--foreground',
'--log-level=2', # debug logging for watchman
]
envb = osenvironb.copy()
envb[b'WATCHMAN_CONFIG_FILE'] = _sys2bytes(cfgfile)
with open(clilogfile, 'wb') as f:
proc = subprocess.Popen(
argv, env=envb, stdin=None, stdout=f, stderr=f
)
try:
yield sockfile
finally:
proc.terminate()
proc.kill()
finally:
if args.keep_fsmonitor_tmpdir:
print('fsmonitor dir available at %s' % basedir)
else:
shutil.rmtree(basedir, ignore_errors=True)
def run():
parser = getparser()
args, runtestsargv = parser.parse_known_args()
with watchman(args) as sockfile:
osenvironb[b'WATCHMAN_SOCK'] = _sys2bytes(sockfile)
# Indicate to hghave that we're running with fsmonitor enabled.
osenvironb[b'HGFSMONITOR_TESTS'] = b'1'
runtestdir = os.path.dirname(__file__)
runtests = os.path.join(runtestdir, 'run-tests.py')
blacklist = os.path.join(runtestdir, 'blacklists', 'fsmonitor')
runtestsargv.insert(0, runtests)
runtestsargv.extend(
[
'--extra-config',
'extensions.fsmonitor=',
# specify fsmonitor.mode=paranoid always in order to force
# fsmonitor extension execute "paranoid" code path
#
# TODO: make fsmonitor-run-tests.py accept specific options
'--extra-config',
'fsmonitor.mode=paranoid',
'--blacklist',
blacklist,
]
)
return subprocess.call(runtestsargv)
if __name__ == '__main__':
sys.exit(run())