Mercurial > hg
view tests/test-verify-repo-operations.py @ 44950:f9734b2d59cc
py3: make stdout line-buffered if connected to a TTY
Status messages that are to be shown on the terminal should be written to the
file descriptor before anything further is done, to keep the user updated.
One common way to achieve this is to make stdout line-buffered if it is
connected to a TTY. This is done on Python 2 (except on Windows, where libc,
which the CPython 2 streams depend on, does not properly support this).
Python 3 rolls it own I/O streams. On Python 3, buffered binary streams can't be
set line-buffered. The previous code (added in 227ba1afcb65) incorrectly
assumed that on Python 3, pycompat.stdout (sys.stdout.buffer) is already
line-buffered. However the interpreter initializes it with a block-buffered
stream or an unbuffered stream (when the -u option or the PYTHONUNBUFFERED
environment variable is set), never with a line-buffered stream.
One example where the current behavior is unacceptable is when running
`hg pull https://www.mercurial-scm.org/repo/hg` on Python 3, where the line
"pulling from https://www.mercurial-scm.org/repo/hg" does not appear on the
terminal before the hg process blocks while waiting for the server.
Various approaches to fix this problem are possible, including:
1. Weaken the contract of procutil.stdout to not give any guarantees about
buffering behavior. In this case, users of procutil.stdout need to be
changed to do enough flushes. In particular,
1. either ui must insert enough flushes for ui.write() and friends, or
2. ui.write() and friends get split into flushing and fully buffered
methods, or
3. users of ui.write() and friends must flush explicitly.
2. Make stdout unbuffered.
3. Make stdout line-buffered. Since Python 3 does not natively support that for
binary streams, we must implement it ourselves.
(2.) is problematic because using unbuffered I/O changes the performance
characteristics significantly compared to line-buffered (which is used on
Python 2) and this would be a regression.
(1.2.) and (1.3) are a substantial amount of work. It’s unclear whether the
added complexity would be justified, given that raw performance doesn’t matter
that much when writing to a terminal much faster than the user could read it.
(1.1.) pushes complexity into the ui class instead of separating the concern of
how stdout is buffered. Other users of procutil.stdout would still need to take
care of the flushes.
This patch implements (3.). The general performance considerations are very
similar to (1.1.). The extra method invocation and method forwarding add a
little more overhead if the class is used. In exchange, it doesn’t add overhead
if not used.
For the benchmarks, I compared the previous implementation (incorrect on Python
3), (1.1.), (3.) and (2.). The command was chosen so that the streams were
configured as if they were writing to a TTY, but actually write to a pager,
which is also the default:
HGRCPATH=/dev/null python3 ./hg --cwd ~/vcs/mozilla-central --time --pager yes --config pager.pager='cat > /dev/null' status --all
previous:
time: real 7.880 secs (user 7.290+0.050 sys 0.580+0.170)
time: real 7.830 secs (user 7.220+0.070 sys 0.590+0.140)
time: real 7.800 secs (user 7.210+0.050 sys 0.570+0.170)
(1.1.) using Yuya Nishihara’s patch:
time: real 9.860 secs (user 8.670+0.350 sys 1.160+0.830)
time: real 9.540 secs (user 8.430+0.370 sys 1.100+0.770)
time: real 9.830 secs (user 8.630+0.370 sys 1.180+0.840)
(3.) using this patch:
time: real 9.580 secs (user 8.480+0.350 sys 1.090+0.770)
time: real 9.670 secs (user 8.480+0.330 sys 1.170+0.860)
time: real 9.640 secs (user 8.500+0.350 sys 1.130+0.810)
(2.) using a previous patch by me:
time: real 10.480 secs (user 8.850+0.720 sys 1.590+1.500)
time: real 10.490 secs (user 8.750+0.750 sys 1.710+1.470)
time: real 10.240 secs (user 8.600+0.700 sys 1.590+1.510)
As expected, there’s no difference on Python 2, as exactly the same code paths
are used:
previous:
time: real 6.950 secs (user 5.870+0.330 sys 1.070+0.770)
time: real 7.040 secs (user 6.040+0.360 sys 0.980+0.750)
time: real 7.070 secs (user 5.950+0.360 sys 1.100+0.760)
this patch:
time: real 7.010 secs (user 5.900+0.390 sys 1.070+0.730)
time: real 7.000 secs (user 5.850+0.350 sys 1.120+0.760)
time: real 7.000 secs (user 5.790+0.380 sys 1.170+0.710)
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Wed, 10 Jun 2020 13:02:39 +0200 |
parents | 2372284d9457 |
children | 89a2afe31e82 |
line wrap: on
line source
from __future__ import print_function, absolute_import """Fuzz testing for operations against a Mercurial repository This uses Hypothesis's stateful testing to generate random repository operations and test Mercurial using them, both to see if there are any unexpected errors and to compare different versions of it.""" import os import subprocess import sys # Only run if slow tests are allowed if subprocess.call(['python', '%s/hghave' % os.environ['TESTDIR'], 'slow']): sys.exit(80) # These tests require Hypothesis and pytz to be installed. # Running 'pip install hypothesis pytz' will achieve that. # Note: This won't work if you're running Python < 2.7. try: from hypothesis.extra.datetime import datetimes except ImportError: sys.stderr.write("skipped: hypothesis or pytz not installed" + os.linesep) sys.exit(80) # If you are running an old version of pip you may find that the enum34 # backport is not installed automatically. If so 'pip install enum34' will # fix this problem. try: import enum assert enum # Silence pyflakes except ImportError: sys.stderr.write("skipped: enum34 not installed" + os.linesep) sys.exit(80) import binascii from contextlib import contextmanager import errno import pipes import shutil import silenttestrunner import subprocess from hypothesis.errors import HypothesisException from hypothesis.stateful import ( rule, RuleBasedStateMachine, Bundle, precondition, ) from hypothesis import settings, note, strategies as st from hypothesis.configuration import set_hypothesis_home_dir from hypothesis.database import ExampleDatabase testdir = os.path.abspath(os.environ["TESTDIR"]) # We store Hypothesis examples here rather in the temporary test directory # so that when rerunning a failing test this always results in refinding the # previous failure. This directory is in .hgignore and should not be checked in # but is useful to have for development. set_hypothesis_home_dir(os.path.join(testdir, ".hypothesis")) runtests = os.path.join(os.environ["RUNTESTDIR"], "run-tests.py") testtmp = os.environ["TESTTMP"] assert os.path.isdir(testtmp) generatedtests = os.path.join(testdir, "hypothesis-generated") try: os.makedirs(generatedtests) except OSError: pass # We write out generated .t files to a file in order to ease debugging and to # give a starting point for turning failures Hypothesis finds into normal # tests. In order to ensure that multiple copies of this test can be run in # parallel we use atomic file create to ensure that we always get a unique # name. file_index = 0 while True: file_index += 1 savefile = os.path.join( generatedtests, "test-generated-%d.t" % (file_index,) ) try: os.close(os.open(savefile, os.O_CREAT | os.O_EXCL | os.O_WRONLY)) break except OSError as e: if e.errno != errno.EEXIST: raise assert os.path.exists(savefile) hgrc = os.path.join(".hg", "hgrc") filecharacters = ( "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" "[]^_`;=@{}~ !#$%&'()+,-" ) files = ( st.text(filecharacters, min_size=1) .map(lambda x: x.strip()) .filter(bool) .map(lambda s: s.encode('ascii')) ) safetext = st.text( st.characters( min_codepoint=1, max_codepoint=127, blacklist_categories=('Cc', 'Cs') ), min_size=1, ).map(lambda s: s.encode('utf-8')) extensions = st.sampled_from(('shelve', 'mq', 'blackbox',)) @contextmanager def acceptableerrors(*args): """Sometimes we know an operation we're about to perform might fail, and we're OK with some of the failures. In those cases this may be used as a context manager and will swallow expected failures, as identified by substrings of the error message Mercurial emits.""" try: yield except subprocess.CalledProcessError as e: if not any(a in e.output for a in args): note(e.output) raise reponames = st.text("abcdefghijklmnopqrstuvwxyz01234556789", min_size=1).map( lambda s: s.encode('ascii') ) class verifyingstatemachine(RuleBasedStateMachine): """This defines the set of acceptable operations on a Mercurial repository using Hypothesis's RuleBasedStateMachine. The general concept is that we manage multiple repositories inside a repos/ directory in our temporary test location. Some of these are freshly inited, some are clones of the others. Our current working directory is always inside one of these repositories while the tests are running. Hypothesis then performs a series of operations against these repositories, including hg commands, generating contents and editing the .hgrc file. If these operations fail in unexpected ways or behave differently in different configurations of Mercurial, the test will fail and a minimized .t test file will be written to the hypothesis-generated directory to exhibit that failure. Operations are defined as methods with @rule() decorators. See the Hypothesis documentation at http://hypothesis.readthedocs.org/en/release/stateful.html for more details.""" # A bundle is a reusable collection of previously generated data which may # be provided as arguments to future operations. repos = Bundle('repos') paths = Bundle('paths') contents = Bundle('contents') branches = Bundle('branches') committimes = Bundle('committimes') def __init__(self): super(verifyingstatemachine, self).__init__() self.repodir = os.path.join(testtmp, "repos") if os.path.exists(self.repodir): shutil.rmtree(self.repodir) os.chdir(testtmp) self.log = [] self.failed = False self.configperrepo = {} self.all_extensions = set() self.non_skippable_extensions = set() self.mkdirp("repos") self.cd("repos") self.mkdirp("repo1") self.cd("repo1") self.hg("init") def teardown(self): """On teardown we clean up after ourselves as usual, but we also do some additional testing: We generate a .t file based on our test run using run-test.py -i to get the correct output. We then test it in a number of other configurations, verifying that each passes the same test.""" super(verifyingstatemachine, self).teardown() try: shutil.rmtree(self.repodir) except OSError: pass ttest = os.linesep.join(" " + l for l in self.log) os.chdir(testtmp) path = os.path.join(testtmp, "test-generated.t") with open(path, 'w') as o: o.write(ttest + os.linesep) with open(os.devnull, "w") as devnull: rewriter = subprocess.Popen( [runtests, "--local", "-i", path], stdin=subprocess.PIPE, stdout=devnull, stderr=devnull, ) rewriter.communicate("yes") with open(path, 'r') as i: ttest = i.read() e = None if not self.failed: try: output = subprocess.check_output( [runtests, path, "--local", "--pure"], stderr=subprocess.STDOUT, ) assert "Ran 1 test" in output, output for ext in self.all_extensions - self.non_skippable_extensions: tf = os.path.join( testtmp, "test-generated-no-%s.t" % (ext,) ) with open(tf, 'w') as o: for l in ttest.splitlines(): if l.startswith(" $ hg"): l = l.replace( "--config %s=" % (extensionconfigkey(ext),), "", ) o.write(l + os.linesep) with open(tf, 'r') as r: t = r.read() assert ext not in t, t output = subprocess.check_output( [runtests, tf, "--local",], stderr=subprocess.STDOUT ) assert "Ran 1 test" in output, output except subprocess.CalledProcessError as e: note(e.output) if self.failed or e is not None: with open(savefile, "wb") as o: o.write(ttest) if e is not None: raise e def execute_step(self, step): try: return super(verifyingstatemachine, self).execute_step(step) except (HypothesisException, KeyboardInterrupt): raise except Exception: self.failed = True raise # Section: Basic commands. def mkdirp(self, path): if os.path.exists(path): return self.log.append( "$ mkdir -p -- %s" % (pipes.quote(os.path.relpath(path)),) ) os.makedirs(path) def cd(self, path): path = os.path.relpath(path) if path == ".": return os.chdir(path) self.log.append("$ cd -- %s" % (pipes.quote(path),)) def hg(self, *args): extra_flags = [] for key, value in self.config.items(): extra_flags.append("--config") extra_flags.append("%s=%s" % (key, value)) self.command("hg", *(tuple(extra_flags) + args)) def command(self, *args): self.log.append("$ " + ' '.join(map(pipes.quote, args))) subprocess.check_output(args, stderr=subprocess.STDOUT) # Section: Set up basic data # This section has no side effects but generates data that we will want # to use later. @rule( target=paths, source=st.lists(files, min_size=1).map(lambda l: os.path.join(*l)), ) def genpath(self, source): return source @rule( target=committimes, when=datetimes(min_year=1970, max_year=2038) | st.none(), ) def gentime(self, when): return when @rule( target=contents, content=st.one_of( st.binary(), st.text().map(lambda x: x.encode('utf-8')) ), ) def gencontent(self, content): return content @rule( target=branches, name=safetext, ) def genbranch(self, name): return name @rule(target=paths, source=paths) def lowerpath(self, source): return source.lower() @rule(target=paths, source=paths) def upperpath(self, source): return source.upper() # Section: Basic path operations @rule(path=paths, content=contents) def writecontent(self, path, content): self.unadded_changes = True if os.path.isdir(path): return parent = os.path.dirname(path) if parent: try: self.mkdirp(parent) except OSError: # It may be the case that there is a regular file that has # previously been created that has the same name as an ancestor # of the current path. This will cause mkdirp to fail with this # error. We just turn this into a no-op in that case. return with open(path, 'wb') as o: o.write(content) self.log.append( ( "$ python -c 'import binascii; " "print(binascii.unhexlify(\"%s\"))' > %s" ) % (binascii.hexlify(content), pipes.quote(path),) ) @rule(path=paths) def addpath(self, path): if os.path.exists(path): self.hg("add", "--", path) @rule(path=paths) def forgetpath(self, path): if os.path.exists(path): with acceptableerrors("file is already untracked",): self.hg("forget", "--", path) @rule(s=st.none() | st.integers(0, 100)) def addremove(self, s): args = ["addremove"] if s is not None: args.extend(["-s", str(s)]) self.hg(*args) @rule(path=paths) def removepath(self, path): if os.path.exists(path): with acceptableerrors( 'file is untracked', 'file has been marked for add', 'file is modified', ): self.hg("remove", "--", path) @rule( message=safetext, amend=st.booleans(), when=committimes, addremove=st.booleans(), secret=st.booleans(), close_branch=st.booleans(), ) def maybecommit( self, message, amend, when, addremove, secret, close_branch ): command = ["commit"] errors = ["nothing changed"] if amend: errors.append("cannot amend public changesets") command.append("--amend") command.append("-m" + pipes.quote(message)) if secret: command.append("--secret") if close_branch: command.append("--close-branch") errors.append("can only close branch heads") if addremove: command.append("--addremove") if when is not None: if when.year == 1970: errors.append('negative date value') if when.year == 2038: errors.append('exceeds 32 bits') command.append( "--date=%s" % (when.strftime('%Y-%m-%d %H:%M:%S %z'),) ) with acceptableerrors(*errors): self.hg(*command) # Section: Repository management @property def currentrepo(self): return os.path.basename(os.getcwd()) @property def config(self): return self.configperrepo.setdefault(self.currentrepo, {}) @rule( target=repos, source=repos, name=reponames, ) def clone(self, source, name): if not os.path.exists(os.path.join("..", name)): self.cd("..") self.hg("clone", source, name) self.cd(name) return name @rule( target=repos, name=reponames, ) def fresh(self, name): if not os.path.exists(os.path.join("..", name)): self.cd("..") self.mkdirp(name) self.cd(name) self.hg("init") return name @rule(name=repos) def switch(self, name): self.cd(os.path.join("..", name)) assert self.currentrepo == name assert os.path.exists(".hg") @rule(target=repos) def origin(self): return "repo1" @rule() def pull(self, repo=repos): with acceptableerrors( "repository default not found", "repository is unrelated", ): self.hg("pull") @rule(newbranch=st.booleans()) def push(self, newbranch): with acceptableerrors( "default repository not configured", "no changes found", ): if newbranch: self.hg("push", "--new-branch") else: with acceptableerrors("creates new branches"): self.hg("push") # Section: Simple side effect free "check" operations @rule() def log(self): self.hg("log") @rule() def verify(self): self.hg("verify") @rule() def diff(self): self.hg("diff", "--nodates") @rule() def status(self): self.hg("status") @rule() def export(self): self.hg("export") # Section: Branch management @rule() def checkbranch(self): self.hg("branch") @rule(branch=branches) def switchbranch(self, branch): with acceptableerrors( 'cannot use an integer as a name', 'cannot be used in a name', 'a branch of the same name already exists', 'is reserved', ): self.hg("branch", "--", branch) @rule(branch=branches, clean=st.booleans()) def update(self, branch, clean): with acceptableerrors( 'unknown revision', 'parse error', ): if clean: self.hg("update", "-C", "--", branch) else: self.hg("update", "--", branch) # Section: Extension management def hasextension(self, extension): return extensionconfigkey(extension) in self.config def commandused(self, extension): assert extension in self.all_extensions self.non_skippable_extensions.add(extension) @rule(extension=extensions) def addextension(self, extension): self.all_extensions.add(extension) self.config[extensionconfigkey(extension)] = "" @rule(extension=extensions) def removeextension(self, extension): self.config.pop(extensionconfigkey(extension), None) # Section: Commands from the shelve extension @rule() @precondition(lambda self: self.hasextension("shelve")) def shelve(self): self.commandused("shelve") with acceptableerrors("nothing changed"): self.hg("shelve") @rule() @precondition(lambda self: self.hasextension("shelve")) def unshelve(self): self.commandused("shelve") with acceptableerrors("no shelved changes to apply"): self.hg("unshelve") class writeonlydatabase(ExampleDatabase): def __init__(self, underlying): super(ExampleDatabase, self).__init__() self.underlying = underlying def fetch(self, key): return () def save(self, key, value): self.underlying.save(key, value) def delete(self, key, value): self.underlying.delete(key, value) def close(self): self.underlying.close() def extensionconfigkey(extension): return "extensions." + extension settings.register_profile( 'default', settings(timeout=300, stateful_step_count=50, max_examples=10,) ) settings.register_profile( 'fast', settings( timeout=10, stateful_step_count=20, max_examples=5, min_satisfying_examples=1, max_shrinks=0, ), ) settings.register_profile( 'continuous', settings( timeout=-1, stateful_step_count=1000, max_examples=10 ** 8, max_iterations=10 ** 8, database=writeonlydatabase(settings.default.database), ), ) settings.load_profile(os.getenv('HYPOTHESIS_PROFILE', 'default')) verifyingtest = verifyingstatemachine.TestCase verifyingtest.settings = settings.default if __name__ == '__main__': try: silenttestrunner.main(__name__) finally: # So as to prevent proliferation of useless test files, if we never # actually wrote a failing test we clean up after ourselves and delete # the file for doing so that we owned. if os.path.exists(savefile) and os.path.getsize(savefile) == 0: os.unlink(savefile)