# __init__.py - fsmonitor initialization and overrides
#
# Copyright 2013-2016 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.
'''Faster status operations with the Watchman file monitor (EXPERIMENTAL)
Integrates the file-watching program Watchman with Mercurial to produce faster
status results.
On a particular Linux system, for a real-world repository with over 400,000
files hosted on ext4, vanilla `hg status` takes 1.3 seconds. On the same
system, with fsmonitor it takes about 0.3 seconds.
fsmonitor requires no configuration -- it will tell Watchman about your
repository as necessary. You'll need to install Watchman from
https://facebook.github.io/watchman/ and make sure it is in your PATH.
fsmonitor is incompatible with the largefiles and eol extensions, and
will disable itself if any of those are active.
The following configuration options exist:
::
[fsmonitor]
mode = {off, on, paranoid}
When `mode = off`, fsmonitor will disable itself (similar to not loading the
extension at all). When `mode = on`, fsmonitor will be enabled (the default).
When `mode = paranoid`, fsmonitor will query both Watchman and the filesystem,
and ensure that the results are consistent.
::
[fsmonitor]
timeout = (float)
A value, in seconds, that determines how long fsmonitor will wait for Watchman
to return results. Defaults to `2.0`.
::
[fsmonitor]
blacklistusers = (list of userids)
A list of usernames for which fsmonitor will disable itself altogether.
::
[fsmonitor]
walk_on_invalidate = (boolean)
Whether or not to walk the whole repo ourselves when our cached state has been
invalidated, for example when Watchman has been restarted or .hgignore rules
have been changed. Walking the repo in that case can result in competing for
I/O with Watchman. For large repos it is recommended to set this value to
false. You may wish to set this to true if you have a very fast filesystem
that can outpace the IPC overhead of getting the result data for the full repo
from Watchman. Defaults to false.
::
[fsmonitor]
warn_when_unused = (boolean)
Whether to print a warning during certain operations when fsmonitor would be
beneficial to performance but isn't enabled.
::
[fsmonitor]
warn_update_file_count = (integer)
If ``warn_when_unused`` is set and fsmonitor isn't enabled, a warning will
be printed during working directory updates if this many files will be
created.
'''
# Platforms Supported
# ===================
#
# **Linux:** *Stable*. Watchman and fsmonitor are both known to work reliably,
# even under severe loads.
#
# **Mac OS X:** *Stable*. The Mercurial test suite passes with fsmonitor
# turned on, on case-insensitive HFS+. There has been a reasonable amount of
# user testing under normal loads.
#
# **Solaris, BSD:** *Alpha*. watchman and fsmonitor are believed to work, but
# very little testing has been done.
#
# **Windows:** *Alpha*. Not in a release version of watchman or fsmonitor yet.
#
# Known Issues
# ============
#
# * fsmonitor will disable itself if any of the following extensions are
# enabled: largefiles, inotify, eol; or if the repository has subrepos.
# * fsmonitor will produce incorrect results if nested repos that are not
# subrepos exist. *Workaround*: add nested repo paths to your `.hgignore`.
#
# The issues related to nested repos and subrepos are probably not fundamental
# ones. Patches to fix them are welcome.
from __future__ import absolute_import
import codecs
import hashlib
import os
import stat
import sys
import weakref
from mercurial.i18n import _
from mercurial.node import (
hex,
)
from mercurial import (
context,
encoding,
error,
extensions,
localrepo,
merge,
pathutil,
pycompat,
registrar,
scmutil,
util,
)
from mercurial import match as matchmod
from . import (
pywatchman,
state,
watchmanclient,
)
# 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 = 'ships-with-hg-core'
configtable = {}
configitem = registrar.configitem(configtable)
configitem('fsmonitor', 'mode',
default='on',
)
configitem('fsmonitor', 'walk_on_invalidate',
default=False,
)
configitem('fsmonitor', 'timeout',
default='2',
)
configitem('fsmonitor', 'blacklistusers',
default=list,
)
configitem('experimental', 'fsmonitor.transaction_notify',
default=False,
)
# This extension is incompatible with the following blacklisted extensions
# and will disable itself when encountering one of these:
_blacklist = ['largefiles', 'eol']
def _handleunavailable(ui, state, ex):
"""Exception handler for Watchman interaction exceptions"""
if isinstance(ex, watchmanclient.Unavailable):
if ex.warn:
ui.warn(str(ex) + '\n')
if ex.invalidate:
state.invalidate()
ui.log('fsmonitor', 'Watchman unavailable: %s\n', ex.msg)
else:
ui.log('fsmonitor', 'Watchman exception: %s\n', ex)
def _hashignore(ignore):
"""Calculate hash for ignore patterns and filenames
If this information changes between Mercurial invocations, we can't
rely on Watchman information anymore and have to re-scan the working
copy.
"""
sha1 = hashlib.sha1()
sha1.update(repr(ignore))
return sha1.hexdigest()
_watchmanencoding = pywatchman.encoding.get_local_encoding()
_fsencoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
_fixencoding = codecs.lookup(_watchmanencoding) != codecs.lookup(_fsencoding)
def _watchmantofsencoding(path):
"""Fix path to match watchman and local filesystem encoding
watchman's paths encoding can differ from filesystem encoding. For example,
on Windows, it's always utf-8.
"""
try:
decoded = path.decode(_watchmanencoding)
except UnicodeDecodeError as e:
raise error.Abort(str(e), hint='watchman encoding error')
try:
encoded = decoded.encode(_fsencoding, 'strict')
except UnicodeEncodeError as e:
raise error.Abort(str(e))
return encoded
def overridewalk(orig, self, match, subrepos, unknown, ignored, full=True):
'''Replacement for dirstate.walk, hooking into Watchman.
Whenever full is False, ignored is False, and the Watchman client is
available, use Watchman combined with saved state to possibly return only a
subset of files.'''
def bail(reason):
self._ui.debug('fsmonitor: fallback to core status, %s\n' % reason)
return orig(match, subrepos, unknown, ignored, full=True)
if full:
return bail('full rewalk requested')
if ignored:
return bail('listing ignored files')
if not self._watchmanclient.available():
return bail('client unavailable')
state = self._fsmonitorstate
clock, ignorehash, notefiles = state.get()
if not clock:
if state.walk_on_invalidate:
return bail('no clock')
# Initial NULL clock value, see
# https://facebook.github.io/watchman/docs/clockspec.html
clock = 'c:0:0'
notefiles = []
def fwarn(f, msg):
self._ui.warn('%s: %s\n' % (self.pathto(f), msg))
return False
def badtype(mode):
kind = _('unknown')
if stat.S_ISCHR(mode):
kind = _('character device')
elif stat.S_ISBLK(mode):
kind = _('block device')
elif stat.S_ISFIFO(mode):
kind = _('fifo')
elif stat.S_ISSOCK(mode):
kind = _('socket')
elif stat.S_ISDIR(mode):
kind = _('directory')
return _('unsupported file type (type is %s)') % kind
ignore = self._ignore
dirignore = self._dirignore
if unknown:
if _hashignore(ignore) != ignorehash and clock != 'c:0:0':
# ignore list changed -- can't rely on Watchman state any more
if state.walk_on_invalidate:
return bail('ignore rules changed')
notefiles = []
clock = 'c:0:0'
else:
# always ignore
ignore = util.always
dirignore = util.always
matchfn = match.matchfn
matchalways = match.always()
dmap = self._map
if util.safehasattr(dmap, '_map'):
# for better performance, directly access the inner dirstate map if the
# standard dirstate implementation is in use.
dmap = dmap._map
nonnormalset = self._map.nonnormalset
copymap = self._map.copymap
getkind = stat.S_IFMT
dirkind = stat.S_IFDIR
regkind = stat.S_IFREG
lnkkind = stat.S_IFLNK
join = self._join
normcase = util.normcase
fresh_instance = False
exact = skipstep3 = False
if match.isexact(): # match.exact
exact = True
dirignore = util.always # skip step 2
elif match.prefix(): # match.match, no patterns
skipstep3 = True
if not exact and self._checkcase:
# note that even though we could receive directory entries, we're only
# interested in checking if a file with the same name exists. So only
# normalize files if possible.
normalize = self._normalizefile
skipstep3 = False
else:
normalize = None
# step 1: find all explicit files
results, work, dirsnotfound = self._walkexplicit(match, subrepos)
skipstep3 = skipstep3 and not (work or dirsnotfound)
work = [d for d in work if not dirignore(d[0])]
if not work and (exact or skipstep3):
for s in subrepos:
del results[s]
del results['.hg']
return results
# step 2: query Watchman
try:
# Use the user-configured timeout for the query.
# Add a little slack over the top of the user query to allow for
# overheads while transferring the data
self._watchmanclient.settimeout(state.timeout + 0.1)
result = self._watchmanclient.command('query', {
'fields': ['mode', 'mtime', 'size', 'exists', 'name'],
'since': clock,
'expression': [
'not', [
'anyof', ['dirname', '.hg'],
['name', '.hg', 'wholename']
]
],
'sync_timeout': int(state.timeout * 1000),
'empty_on_fresh_instance': state.walk_on_invalidate,
})
except Exception as ex:
_handleunavailable(self._ui, state, ex)
self._watchmanclient.clearconnection()
return bail('exception during run')
else:
# We need to propagate the last observed clock up so that we
# can use it for our next query
state.setlastclock(result['clock'])
if result['is_fresh_instance']:
if state.walk_on_invalidate:
state.invalidate()
return bail('fresh instance')
fresh_instance = True
# Ignore any prior noteable files from the state info
notefiles = []
# for file paths which require normalization and we encounter a case
# collision, we store our own foldmap
if normalize:
foldmap = dict((normcase(k), k) for k in results)
switch_slashes = pycompat.ossep == '\\'
# The order of the results is, strictly speaking, undefined.
# For case changes on a case insensitive filesystem we may receive
# two entries, one with exists=True and another with exists=False.
# The exists=True entries in the same response should be interpreted
# as being happens-after the exists=False entries due to the way that
# Watchman tracks files. We use this property to reconcile deletes
# for name case changes.
for entry in result['files']:
fname = entry['name']
if _fixencoding:
fname = _watchmantofsencoding(fname)
if switch_slashes:
fname = fname.replace('\\', '/')
if normalize:
normed = normcase(fname)
fname = normalize(fname, True, True)
foldmap[normed] = fname
fmode = entry['mode']
fexists = entry['exists']
kind = getkind(fmode)
if not fexists:
# if marked as deleted and we don't already have a change
# record, mark it as deleted. If we already have an entry
# for fname then it was either part of walkexplicit or was
# an earlier result that was a case change
if fname not in results and fname in dmap and (
matchalways or matchfn(fname)):
results[fname] = None
elif kind == dirkind:
if fname in dmap and (matchalways or matchfn(fname)):
results[fname] = None
elif kind == regkind or kind == lnkkind:
if fname in dmap:
if matchalways or matchfn(fname):
results[fname] = entry
elif (matchalways or matchfn(fname)) and not ignore(fname):
results[fname] = entry
elif fname in dmap and (matchalways or matchfn(fname)):
results[fname] = None
# step 3: query notable files we don't already know about
# XXX try not to iterate over the entire dmap
if normalize:
# any notable files that have changed case will already be handled
# above, so just check membership in the foldmap
notefiles = set((normalize(f, True, True) for f in notefiles
if normcase(f) not in foldmap))
visit = set((f for f in notefiles if (f not in results and matchfn(f)
and (f in dmap or not ignore(f)))))
if not fresh_instance:
if matchalways:
visit.update(f for f in nonnormalset if f not in results)
visit.update(f for f in copymap if f not in results)
else:
visit.update(f for f in nonnormalset
if f not in results and matchfn(f))
visit.update(f for f in copymap
if f not in results and matchfn(f))
else:
if matchalways:
visit.update(f for f, st in dmap.iteritems() if f not in results)
visit.update(f for f in copymap if f not in results)
else:
visit.update(f for f, st in dmap.iteritems()
if f not in results and matchfn(f))
visit.update(f for f in copymap
if f not in results and matchfn(f))
audit = pathutil.pathauditor(self._root, cached=True).check
auditpass = [f for f in visit if audit(f)]
auditpass.sort()
auditfail = visit.difference(auditpass)
for f in auditfail:
results[f] = None
nf = iter(auditpass).next
for st in util.statfiles([join(f) for f in auditpass]):
f = nf()
if st or f in dmap:
results[f] = st
for s in subrepos:
del results[s]
del results['.hg']
return results
def overridestatus(
orig, self, node1='.', node2=None, match=None, ignored=False,
clean=False, unknown=False, listsubrepos=False):
listignored = ignored
listclean = clean
listunknown = unknown
def _cmpsets(l1, l2):
try:
if 'FSMONITOR_LOG_FILE' in encoding.environ:
fn = encoding.environ['FSMONITOR_LOG_FILE']
f = open(fn, 'wb')
else:
fn = 'fsmonitorfail.log'
f = self.opener(fn, 'wb')
except (IOError, OSError):
self.ui.warn(_('warning: unable to write to %s\n') % fn)
return
try:
for i, (s1, s2) in enumerate(zip(l1, l2)):
if set(s1) != set(s2):
f.write('sets at position %d are unequal\n' % i)
f.write('watchman returned: %s\n' % s1)
f.write('stat returned: %s\n' % s2)
finally:
f.close()
if isinstance(node1, context.changectx):
ctx1 = node1
else:
ctx1 = self[node1]
if isinstance(node2, context.changectx):
ctx2 = node2
else:
ctx2 = self[node2]
working = ctx2.rev() is None
parentworking = working and ctx1 == self['.']
match = match or matchmod.always(self.root, self.getcwd())
# Maybe we can use this opportunity to update Watchman's state.
# Mercurial uses workingcommitctx and/or memctx to represent the part of
# the workingctx that is to be committed. So don't update the state in
# that case.
# HG_PENDING is set in the environment when the dirstate is being updated
# in the middle of a transaction; we must not update our state in that
# case, or we risk forgetting about changes in the working copy.
updatestate = (parentworking and match.always() and
not isinstance(ctx2, (context.workingcommitctx,
context.memctx)) and
'HG_PENDING' not in encoding.environ)
try:
if self._fsmonitorstate.walk_on_invalidate:
# Use a short timeout to query the current clock. If that
# takes too long then we assume that the service will be slow
# to answer our query.
# walk_on_invalidate indicates that we prefer to walk the
# tree ourselves because we can ignore portions that Watchman
# cannot and we tend to be faster in the warmer buffer cache
# cases.
self._watchmanclient.settimeout(0.1)
else:
# Give Watchman more time to potentially complete its walk
# and return the initial clock. In this mode we assume that
# the filesystem will be slower than parsing a potentially
# very large Watchman result set.
self._watchmanclient.settimeout(
self._fsmonitorstate.timeout + 0.1)
startclock = self._watchmanclient.getcurrentclock()
except Exception as ex:
self._watchmanclient.clearconnection()
_handleunavailable(self.ui, self._fsmonitorstate, ex)
# boo, Watchman failed. bail
return orig(node1, node2, match, listignored, listclean,
listunknown, listsubrepos)
if updatestate:
# We need info about unknown files. This may make things slower the
# first time, but whatever.
stateunknown = True
else:
stateunknown = listunknown
if updatestate:
ps = poststatus(startclock)
self.addpostdsstatus(ps)
r = orig(node1, node2, match, listignored, listclean, stateunknown,
listsubrepos)
modified, added, removed, deleted, unknown, ignored, clean = r
if not listunknown:
unknown = []
# don't do paranoid checks if we're not going to query Watchman anyway
full = listclean or match.traversedir is not None
if self._fsmonitorstate.mode == 'paranoid' and not full:
# run status again and fall back to the old walk this time
self.dirstate._fsmonitordisable = True
# shut the UI up
quiet = self.ui.quiet
self.ui.quiet = True
fout, ferr = self.ui.fout, self.ui.ferr
self.ui.fout = self.ui.ferr = open(os.devnull, 'wb')
try:
rv2 = orig(
node1, node2, match, listignored, listclean, listunknown,
listsubrepos)
finally:
self.dirstate._fsmonitordisable = False
self.ui.quiet = quiet
self.ui.fout, self.ui.ferr = fout, ferr
# clean isn't tested since it's set to True above
_cmpsets([modified, added, removed, deleted, unknown, ignored, clean],
rv2)
modified, added, removed, deleted, unknown, ignored, clean = rv2
return scmutil.status(
modified, added, removed, deleted, unknown, ignored, clean)
class poststatus(object):
def __init__(self, startclock):
self._startclock = startclock
def __call__(self, wctx, status):
clock = wctx.repo()._fsmonitorstate.getlastclock() or self._startclock
hashignore = _hashignore(wctx.repo().dirstate._ignore)
notefiles = (status.modified + status.added + status.removed +
status.deleted + status.unknown)
wctx.repo()._fsmonitorstate.set(clock, hashignore, notefiles)
def makedirstate(repo, dirstate):
class fsmonitordirstate(dirstate.__class__):
def _fsmonitorinit(self, repo):
# _fsmonitordisable is used in paranoid mode
self._fsmonitordisable = False
self._fsmonitorstate = repo._fsmonitorstate
self._watchmanclient = repo._watchmanclient
self._repo = weakref.proxy(repo)
def walk(self, *args, **kwargs):
orig = super(fsmonitordirstate, self).walk
if self._fsmonitordisable:
return orig(*args, **kwargs)
return overridewalk(orig, self, *args, **kwargs)
def rebuild(self, *args, **kwargs):
self._fsmonitorstate.invalidate()
return super(fsmonitordirstate, self).rebuild(*args, **kwargs)
def invalidate(self, *args, **kwargs):
self._fsmonitorstate.invalidate()
return super(fsmonitordirstate, self).invalidate(*args, **kwargs)
dirstate.__class__ = fsmonitordirstate
dirstate._fsmonitorinit(repo)
def wrapdirstate(orig, self):
ds = orig(self)
# only override the dirstate when Watchman is available for the repo
if util.safehasattr(self, '_fsmonitorstate'):
makedirstate(self, ds)
return ds
def extsetup(ui):
extensions.wrapfilecache(
localrepo.localrepository, 'dirstate', wrapdirstate)
if pycompat.isdarwin:
# An assist for avoiding the dangling-symlink fsevents bug
extensions.wrapfunction(os, 'symlink', wrapsymlink)
extensions.wrapfunction(merge, 'update', wrapupdate)
def wrapsymlink(orig, source, link_name):
''' if we create a dangling symlink, also touch the parent dir
to encourage fsevents notifications to work more correctly '''
try:
return orig(source, link_name)
finally:
try:
os.utime(os.path.dirname(link_name), None)
except OSError:
pass
class state_update(object):
''' This context manager is responsible for dispatching the state-enter
and state-leave signals to the watchman service. The enter and leave
methods can be invoked manually (for scenarios where context manager
semantics are not possible). If parameters oldnode and newnode are None,
they will be populated based on current working copy in enter and
leave, respectively. Similarly, if the distance is none, it will be
calculated based on the oldnode and newnode in the leave method.'''
def __init__(self, repo, name, oldnode=None, newnode=None, distance=None,
partial=False):
self.repo = repo.unfiltered()
self.name = name
self.oldnode = oldnode
self.newnode = newnode
self.distance = distance
self.partial = partial
self._lock = None
self.need_leave = False
def __enter__(self):
self.enter()
def enter(self):
# Make sure we have a wlock prior to sending notifications to watchman.
# We don't want to race with other actors. In the update case,
# merge.update is going to take the wlock almost immediately. We are
# effectively extending the lock around several short sanity checks.
if self.oldnode is None:
self.oldnode = self.repo['.'].node()
if self.repo.currentwlock() is None:
if util.safehasattr(self.repo, 'wlocknostateupdate'):
self._lock = self.repo.wlocknostateupdate()
else:
self._lock = self.repo.wlock()
self.need_leave = self._state(
'state-enter',
hex(self.oldnode))
return self
def __exit__(self, type_, value, tb):
abort = True if type_ else False
self.exit(abort=abort)
def exit(self, abort=False):
try:
if self.need_leave:
status = 'failed' if abort else 'ok'
if self.newnode is None:
self.newnode = self.repo['.'].node()
if self.distance is None:
self.distance = calcdistance(
self.repo, self.oldnode, self.newnode)
self._state(
'state-leave',
hex(self.newnode),
status=status)
finally:
self.need_leave = False
if self._lock:
self._lock.release()
def _state(self, cmd, commithash, status='ok'):
if not util.safehasattr(self.repo, '_watchmanclient'):
return False
try:
self.repo._watchmanclient.command(cmd, {
'name': self.name,
'metadata': {
# the target revision
'rev': commithash,
# approximate number of commits between current and target
'distance': self.distance if self.distance else 0,
# success/failure (only really meaningful for state-leave)
'status': status,
# whether the working copy parent is changing
'partial': self.partial,
}})
return True
except Exception as e:
# Swallow any errors; fire and forget
self.repo.ui.log(
'watchman', 'Exception %s while running %s\n', e, cmd)
return False
# Estimate the distance between two nodes
def calcdistance(repo, oldnode, newnode):
anc = repo.changelog.ancestor(oldnode, newnode)
ancrev = repo[anc].rev()
distance = (abs(repo[oldnode].rev() - ancrev)
+ abs(repo[newnode].rev() - ancrev))
return distance
# Bracket working copy updates with calls to the watchman state-enter
# and state-leave commands. This allows clients to perform more intelligent
# settling during bulk file change scenarios
# https://facebook.github.io/watchman/docs/cmd/subscribe.html#advanced-settling
def wrapupdate(orig, repo, node, branchmerge, force, ancestor=None,
mergeancestor=False, labels=None, matcher=None, **kwargs):
distance = 0
partial = True
oldnode = repo['.'].node()
newnode = repo[node].node()
if matcher is None or matcher.always():
partial = False
distance = calcdistance(repo.unfiltered(), oldnode, newnode)
with state_update(repo, name="hg.update", oldnode=oldnode, newnode=newnode,
distance=distance, partial=partial):
return orig(
repo, node, branchmerge, force, ancestor, mergeancestor,
labels, matcher, **kwargs)
def reposetup(ui, repo):
# We don't work with largefiles or inotify
exts = extensions.enabled()
for ext in _blacklist:
if ext in exts:
ui.warn(_('The fsmonitor extension is incompatible with the %s '
'extension and has been disabled.\n') % ext)
return
if repo.local():
# We don't work with subrepos either.
#
# if repo[None].substate can cause a dirstate parse, which is too
# slow. Instead, look for a file called hgsubstate,
if repo.wvfs.exists('.hgsubstate') or repo.wvfs.exists('.hgsub'):
return
fsmonitorstate = state.state(repo)
if fsmonitorstate.mode == 'off':
return
try:
client = watchmanclient.client(repo)
except Exception as ex:
_handleunavailable(ui, fsmonitorstate, ex)
return
repo._fsmonitorstate = fsmonitorstate
repo._watchmanclient = client
dirstate, cached = localrepo.isfilecached(repo, 'dirstate')
if cached:
# at this point since fsmonitorstate wasn't present,
# repo.dirstate is not a fsmonitordirstate
makedirstate(repo, dirstate)
class fsmonitorrepo(repo.__class__):
def status(self, *args, **kwargs):
orig = super(fsmonitorrepo, self).status
return overridestatus(orig, self, *args, **kwargs)
def wlocknostateupdate(self, *args, **kwargs):
return super(fsmonitorrepo, self).wlock(*args, **kwargs)
def wlock(self, *args, **kwargs):
l = super(fsmonitorrepo, self).wlock(*args, **kwargs)
if not ui.configbool(
"experimental", "fsmonitor.transaction_notify"):
return l
if l.held != 1:
return l
origrelease = l.releasefn
def staterelease():
if origrelease:
origrelease()
if l.stateupdate:
l.stateupdate.exit()
l.stateupdate = None
try:
l.stateupdate = None
l.stateupdate = state_update(self, name="hg.transaction")
l.stateupdate.enter()
l.releasefn = staterelease
except Exception as e:
# Swallow any errors; fire and forget
self.ui.log(
'watchman', 'Exception in state update %s\n', e)
return l
repo.__class__ = fsmonitorrepo