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.
# blackbox.py - log repository events to a file for post-mortem debugging
#
# Copyright 2010 Nicolas Dumazet
# Copyright 2013 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.
"""log repository events to a blackbox for debugging
Logs event information to .hg/blackbox.log to help debug and diagnose problems.
The events that get logged can be configured via the blackbox.track and
blackbox.ignore config keys.
Examples::
[blackbox]
track = *
ignore = pythonhook
# dirty is *EXPENSIVE* (slow);
# each log entry indicates `+` if the repository is dirty, like :hg:`id`.
dirty = True
# record the source of log messages
logsource = True
[blackbox]
track = command, commandfinish, commandexception, exthook, pythonhook
[blackbox]
track = incoming
[blackbox]
# limit the size of a log file
maxsize = 1.5 MB
# rotate up to N log files when the current one gets too big
maxfiles = 3
[blackbox]
# Include microseconds in log entries with %f (see Python function
# datetime.datetime.strftime)
date-format = %Y-%m-%d @ %H:%M:%S.%f
"""
import re
from mercurial.i18n import _
from mercurial.node import hex
from mercurial import (
encoding,
loggingutil,
registrar,
)
from mercurial.utils import (
dateutil,
procutil,
)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'
cmdtable = {}
command = registrar.command(cmdtable)
configtable = {}
configitem = registrar.configitem(configtable)
configitem(
b'blackbox',
b'dirty',
default=False,
)
configitem(
b'blackbox',
b'maxsize',
default=b'1 MB',
)
configitem(
b'blackbox',
b'logsource',
default=False,
)
configitem(
b'blackbox',
b'maxfiles',
default=7,
)
configitem(
b'blackbox',
b'track',
default=lambda: [b'*'],
)
configitem(
b'blackbox',
b'ignore',
default=lambda: [b'chgserver', b'cmdserver', b'extension'],
)
configitem(b'blackbox', b'date-format', default=b'')
_lastlogger = loggingutil.proxylogger()
class blackboxlogger:
def __init__(self, ui, repo):
self._repo = repo
self._trackedevents = set(ui.configlist(b'blackbox', b'track'))
self._ignoredevents = set(ui.configlist(b'blackbox', b'ignore'))
self._maxfiles = ui.configint(b'blackbox', b'maxfiles')
self._maxsize = ui.configbytes(b'blackbox', b'maxsize')
self._inlog = False
def tracked(self, event):
return (
b'*' in self._trackedevents and event not in self._ignoredevents
) or event in self._trackedevents
def log(self, ui, event, msg, opts):
# self._log() -> ctx.dirty() may create new subrepo instance, which
# ui is derived from baseui. So the recursion guard in ui.log()
# doesn't work as it's local to the ui instance.
if self._inlog:
return
self._inlog = True
try:
self._log(ui, event, msg, opts)
finally:
self._inlog = False
def _log(self, ui, event, msg, opts):
default = ui.configdate(b'devel', b'default-date')
dateformat = ui.config(b'blackbox', b'date-format')
if dateformat:
date = dateutil.datestr(default, dateformat)
else:
# We want to display milliseconds (more precision seems
# unnecessary). Since %.3f is not supported, use %f and truncate
# microseconds.
date = dateutil.datestr(default, b'%Y-%m-%d %H:%M:%S.%f')[:-3]
user = procutil.getuser()
pid = b'%d' % procutil.getpid()
changed = b''
ctx = self._repo[None]
parents = ctx.parents()
rev = b'+'.join([hex(p.node()) for p in parents])
if ui.configbool(b'blackbox', b'dirty') and ctx.dirty(
missing=True, merge=False, branch=False
):
changed = b'+'
if ui.configbool(b'blackbox', b'logsource'):
src = b' [%s]' % event
else:
src = b''
try:
fmt = b'%s %s @%s%s (%s)%s> %s'
args = (date, user, rev, changed, pid, src, msg)
with loggingutil.openlogfile(
ui,
self._repo.vfs,
name=b'blackbox.log',
maxfiles=self._maxfiles,
maxsize=self._maxsize,
) as fp:
fp.write(fmt % args)
except (IOError, OSError) as err:
# deactivate this to avoid failed logging again
self._trackedevents.clear()
ui.debug(
b'warning: cannot write to blackbox.log: %s\n'
% encoding.strtolocal(err.strerror)
)
return
_lastlogger.logger = self
def uipopulate(ui):
ui.setlogger(b'blackbox', _lastlogger)
def reposetup(ui, repo):
# During 'hg pull' a httppeer repo is created to represent the remote repo.
# It doesn't have a .hg directory to put a blackbox in, so we don't do
# the blackbox setup for it.
if not repo.local():
return
# Since blackbox.log is stored in the repo directory, the logger should be
# instantiated per repository.
logger = blackboxlogger(ui, repo)
ui.setlogger(b'blackbox', logger)
# Set _lastlogger even if ui.log is not called. This gives blackbox a
# fallback place to log
if _lastlogger.logger is None:
_lastlogger.logger = logger
repo._wlockfreeprefix.add(b'blackbox.log')
@command(
b'blackbox',
[
(b'l', b'limit', 10, _(b'the number of events to show')),
],
_(b'hg blackbox [OPTION]...'),
helpcategory=command.CATEGORY_MAINTENANCE,
helpbasic=True,
)
def blackbox(ui, repo, *revs, **opts):
"""view the recent repository events"""
if not repo.vfs.exists(b'blackbox.log'):
return
limit = opts.get('limit')
fp = repo.vfs(b'blackbox.log', b'r')
lines = fp.read().split(b'\n')
count = 0
output = []
for line in reversed(lines):
if count >= limit:
break
# count the commands by matching lines like:
# 2013/01/23 19:13:36 root>
# 2013/01/23 19:13:36 root (1234)>
# 2013/01/23 19:13:36 root @0000000000000000000000000000000000000000 (1234)>
# 2013-01-23 19:13:36.000 root @0000000000000000000000000000000000000000 (1234)>
if re.match(
br'^\d{4}[-/]\d{2}[-/]\d{2} \d{2}:\d{2}:\d{2}(.\d*)? .*> .*', line
):
count += 1
output.append(line)
ui.status(b'\n'.join(reversed(output)))