ref: c0d21d35b103e980e658fff1ef07107e72a03364
dir: /sys/src/cmd/hg/hgext/inotify/server.py/
# server.py - inotify status server
#
# Copyright 2006, 2007, 2008 Bryan O'Sullivan <bos@serpentine.com>
# Copyright 2007, 2008 Brendan Cully <brendan@kublai.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.
from mercurial.i18n import _
from mercurial import osutil, util
import common
import errno, os, select, socket, stat, struct, sys, tempfile, time
try:
import linux as inotify
from linux import watcher
except ImportError:
raise
class AlreadyStartedException(Exception): pass
def join(a, b):
if a:
if a[-1] == '/':
return a + b
return a + '/' + b
return b
def split(path):
c = path.rfind('/')
if c == -1:
return '', path
return path[:c], path[c+1:]
walk_ignored_errors = (errno.ENOENT, errno.ENAMETOOLONG)
def walkrepodirs(dirstate, absroot):
'''Iterate over all subdirectories of this repo.
Exclude the .hg directory, any nested repos, and ignored dirs.'''
def walkit(dirname, top):
fullpath = join(absroot, dirname)
try:
for name, kind in osutil.listdir(fullpath):
if kind == stat.S_IFDIR:
if name == '.hg':
if not top:
return
else:
d = join(dirname, name)
if dirstate._ignore(d):
continue
for subdir in walkit(d, False):
yield subdir
except OSError, err:
if err.errno not in walk_ignored_errors:
raise
yield fullpath
return walkit('', True)
def walk(dirstate, absroot, root):
'''Like os.walk, but only yields regular files.'''
# This function is critical to performance during startup.
def walkit(root, reporoot):
files, dirs = [], []
try:
fullpath = join(absroot, root)
for name, kind in osutil.listdir(fullpath):
if kind == stat.S_IFDIR:
if name == '.hg':
if not reporoot:
return
else:
dirs.append(name)
path = join(root, name)
if dirstate._ignore(path):
continue
for result in walkit(path, False):
yield result
elif kind in (stat.S_IFREG, stat.S_IFLNK):
files.append(name)
yield fullpath, dirs, files
except OSError, err:
if err.errno == errno.ENOTDIR:
# fullpath was a directory, but has since been replaced
# by a file.
yield fullpath, dirs, files
elif err.errno not in walk_ignored_errors:
raise
return walkit(root, root == '')
def _explain_watch_limit(ui, dirstate, rootabs):
path = '/proc/sys/fs/inotify/max_user_watches'
try:
limit = int(file(path).read())
except IOError, err:
if err.errno != errno.ENOENT:
raise
raise util.Abort(_('this system does not seem to '
'support inotify'))
ui.warn(_('*** the current per-user limit on the number '
'of inotify watches is %s\n') % limit)
ui.warn(_('*** this limit is too low to watch every '
'directory in this repository\n'))
ui.warn(_('*** counting directories: '))
ndirs = len(list(walkrepodirs(dirstate, rootabs)))
ui.warn(_('found %d\n') % ndirs)
newlimit = min(limit, 1024)
while newlimit < ((limit + ndirs) * 1.1):
newlimit *= 2
ui.warn(_('*** to raise the limit from %d to %d (run as root):\n') %
(limit, newlimit))
ui.warn(_('*** echo %d > %s\n') % (newlimit, path))
raise util.Abort(_('cannot watch %s until inotify watch limit is raised')
% rootabs)
class pollable(object):
"""
Interface to support polling.
The file descriptor returned by fileno() is registered to a polling
object.
Usage:
Every tick, check if an event has happened since the last tick:
* If yes, call handle_events
* If no, call handle_timeout
"""
poll_events = select.POLLIN
instances = {}
poll = select.poll()
def fileno(self):
raise NotImplementedError
def handle_events(self, events):
raise NotImplementedError
def handle_timeout(self):
raise NotImplementedError
def shutdown(self):
raise NotImplementedError
def register(self, timeout):
fd = self.fileno()
pollable.poll.register(fd, pollable.poll_events)
pollable.instances[fd] = self
self.registered = True
self.timeout = timeout
def unregister(self):
pollable.poll.unregister(self)
self.registered = False
@classmethod
def run(cls):
while True:
timeout = None
timeobj = None
for obj in cls.instances.itervalues():
if obj.timeout is not None and (timeout is None or obj.timeout < timeout):
timeout, timeobj = obj.timeout, obj
try:
events = cls.poll.poll(timeout)
except select.error, err:
if err[0] == errno.EINTR:
continue
raise
if events:
by_fd = {}
for fd, event in events:
by_fd.setdefault(fd, []).append(event)
for fd, events in by_fd.iteritems():
cls.instances[fd].handle_pollevents(events)
elif timeobj:
timeobj.handle_timeout()
def eventaction(code):
"""
Decorator to help handle events in repowatcher
"""
def decorator(f):
def wrapper(self, wpath):
if code == 'm' and wpath in self.lastevent and \
self.lastevent[wpath] in 'cm':
return
self.lastevent[wpath] = code
self.timeout = 250
f(self, wpath)
wrapper.func_name = f.func_name
return wrapper
return decorator
class directory(object):
"""
Representing a directory
* path is the relative path from repo root to this directory
* files is a dict listing the files in this directory
- keys are file names
- values are file status
* dirs is a dict listing the subdirectories
- key are subdirectories names
- values are directory objects
"""
def __init__(self, relpath=''):
self.path = relpath
self.files = {}
self.dirs = {}
def dir(self, relpath):
"""
Returns the directory contained at the relative path relpath.
Creates the intermediate directories if necessary.
"""
if not relpath:
return self
l = relpath.split('/')
ret = self
while l:
next = l.pop(0)
try:
ret = ret.dirs[next]
except KeyError:
d = directory(join(ret.path, next))
ret.dirs[next] = d
ret = d
return ret
def walk(self, states):
"""
yield (filename, status) pairs for items in the trees
that have status in states.
filenames are relative to the repo root
"""
for file, st in self.files.iteritems():
if st in states:
yield join(self.path, file), st
for dir in self.dirs.itervalues():
for e in dir.walk(states):
yield e
def lookup(self, states, path):
"""
yield root-relative filenames that match path, and whose
status are in states:
* if path is a file, yield path
* if path is a directory, yield directory files
* if path is not tracked, yield nothing
"""
if path[-1] == '/':
path = path[:-1]
paths = path.split('/')
# we need to check separately for last node
last = paths.pop()
tree = self
try:
for dir in paths:
tree = tree.dirs[dir]
except KeyError:
# path is not tracked
return
try:
# if path is a directory, walk it
for file, st in tree.dirs[last].walk(states):
yield file
except KeyError:
try:
if tree.files[last] in states:
# path is a file
yield path
except KeyError:
# path is not tracked
pass
class repowatcher(pollable):
"""
Watches inotify events
"""
statuskeys = 'almr!?'
mask = (
inotify.IN_ATTRIB |
inotify.IN_CREATE |
inotify.IN_DELETE |
inotify.IN_DELETE_SELF |
inotify.IN_MODIFY |
inotify.IN_MOVED_FROM |
inotify.IN_MOVED_TO |
inotify.IN_MOVE_SELF |
inotify.IN_ONLYDIR |
inotify.IN_UNMOUNT |
0)
def __init__(self, ui, dirstate, root):
self.ui = ui
self.dirstate = dirstate
self.wprefix = join(root, '')
self.prefixlen = len(self.wprefix)
try:
self.watcher = watcher.watcher()
except OSError, err:
raise util.Abort(_('inotify service not available: %s') %
err.strerror)
self.threshold = watcher.threshold(self.watcher)
self.fileno = self.watcher.fileno
self.tree = directory()
self.statcache = {}
self.statustrees = dict([(s, directory()) for s in self.statuskeys])
self.last_event = None
self.lastevent = {}
self.register(timeout=None)
self.ds_info = self.dirstate_info()
self.handle_timeout()
self.scan()
def event_time(self):
last = self.last_event
now = time.time()
self.last_event = now
if last is None:
return 'start'
delta = now - last
if delta < 5:
return '+%.3f' % delta
if delta < 50:
return '+%.2f' % delta
return '+%.1f' % delta
def dirstate_info(self):
try:
st = os.lstat(self.wprefix + '.hg/dirstate')
return st.st_mtime, st.st_ino
except OSError, err:
if err.errno != errno.ENOENT:
raise
return 0, 0
def add_watch(self, path, mask):
if not path:
return
if self.watcher.path(path) is None:
if self.ui.debugflag:
self.ui.note(_('watching %r\n') % path[self.prefixlen:])
try:
self.watcher.add(path, mask)
except OSError, err:
if err.errno in (errno.ENOENT, errno.ENOTDIR):
return
if err.errno != errno.ENOSPC:
raise
_explain_watch_limit(self.ui, self.dirstate, self.wprefix)
def setup(self):
self.ui.note(_('watching directories under %r\n') % self.wprefix)
self.add_watch(self.wprefix + '.hg', inotify.IN_DELETE)
self.check_dirstate()
def filestatus(self, fn, st):
try:
type_, mode, size, time = self.dirstate._map[fn][:4]
except KeyError:
type_ = '?'
if type_ == 'n':
st_mode, st_size, st_mtime = st
if size == -1:
return 'l'
if size and (size != st_size or (mode ^ st_mode) & 0100):
return 'm'
if time != int(st_mtime):
return 'l'
return 'n'
if type_ == '?' and self.dirstate._ignore(fn):
return 'i'
return type_
def updatefile(self, wfn, osstat):
'''
update the file entry of an existing file.
osstat: (mode, size, time) tuple, as returned by os.lstat(wfn)
'''
self._updatestatus(wfn, self.filestatus(wfn, osstat))
def deletefile(self, wfn, oldstatus):
'''
update the entry of a file which has been deleted.
oldstatus: char in statuskeys, status of the file before deletion
'''
if oldstatus == 'r':
newstatus = 'r'
elif oldstatus in 'almn':
newstatus = '!'
else:
newstatus = None
self.statcache.pop(wfn, None)
self._updatestatus(wfn, newstatus)
def _updatestatus(self, wfn, newstatus):
'''
Update the stored status of a file.
newstatus: - char in (statuskeys + 'ni'), new status to apply.
- or None, to stop tracking wfn
'''
root, fn = split(wfn)
d = self.tree.dir(root)
oldstatus = d.files.get(fn)
# oldstatus can be either:
# - None : fn is new
# - a char in statuskeys: fn is a (tracked) file
if self.ui.debugflag and oldstatus != newstatus:
self.ui.note(_('status: %r %s -> %s\n') %
(wfn, oldstatus, newstatus))
if oldstatus and oldstatus in self.statuskeys \
and oldstatus != newstatus:
del self.statustrees[oldstatus].dir(root).files[fn]
if newstatus in (None, 'i'):
d.files.pop(fn, None)
elif oldstatus != newstatus:
d.files[fn] = newstatus
if newstatus != 'n':
self.statustrees[newstatus].dir(root).files[fn] = newstatus
def check_deleted(self, key):
# Files that had been deleted but were present in the dirstate
# may have vanished from the dirstate; we must clean them up.
nuke = []
for wfn, ignore in self.statustrees[key].walk(key):
if wfn not in self.dirstate:
nuke.append(wfn)
for wfn in nuke:
root, fn = split(wfn)
del self.statustrees[key].dir(root).files[fn]
del self.tree.dir(root).files[fn]
def scan(self, topdir=''):
ds = self.dirstate._map.copy()
self.add_watch(join(self.wprefix, topdir), self.mask)
for root, dirs, files in walk(self.dirstate, self.wprefix, topdir):
for d in dirs:
self.add_watch(join(root, d), self.mask)
wroot = root[self.prefixlen:]
for fn in files:
wfn = join(wroot, fn)
self.updatefile(wfn, self.getstat(wfn))
ds.pop(wfn, None)
wtopdir = topdir
if wtopdir and wtopdir[-1] != '/':
wtopdir += '/'
for wfn, state in ds.iteritems():
if not wfn.startswith(wtopdir):
continue
try:
st = self.stat(wfn)
except OSError:
status = state[0]
self.deletefile(wfn, status)
else:
self.updatefile(wfn, st)
self.check_deleted('!')
self.check_deleted('r')
def check_dirstate(self):
ds_info = self.dirstate_info()
if ds_info == self.ds_info:
return
self.ds_info = ds_info
if not self.ui.debugflag:
self.last_event = None
self.ui.note(_('%s dirstate reload\n') % self.event_time())
self.dirstate.invalidate()
self.handle_timeout()
self.scan()
self.ui.note(_('%s end dirstate reload\n') % self.event_time())
def update_hgignore(self):
# An update of the ignore file can potentially change the
# states of all unknown and ignored files.
# XXX If the user has other ignore files outside the repo, or
# changes their list of ignore files at run time, we'll
# potentially never see changes to them. We could get the
# client to report to us what ignore data they're using.
# But it's easier to do nothing than to open that can of
# worms.
if '_ignore' in self.dirstate.__dict__:
delattr(self.dirstate, '_ignore')
self.ui.note(_('rescanning due to .hgignore change\n'))
self.handle_timeout()
self.scan()
def getstat(self, wpath):
try:
return self.statcache[wpath]
except KeyError:
try:
return self.stat(wpath)
except OSError, err:
if err.errno != errno.ENOENT:
raise
def stat(self, wpath):
try:
st = os.lstat(join(self.wprefix, wpath))
ret = st.st_mode, st.st_size, st.st_mtime
self.statcache[wpath] = ret
return ret
except OSError:
self.statcache.pop(wpath, None)
raise
@eventaction('c')
def created(self, wpath):
if wpath == '.hgignore':
self.update_hgignore()
try:
st = self.stat(wpath)
if stat.S_ISREG(st[0]):
self.updatefile(wpath, st)
except OSError:
pass
@eventaction('m')
def modified(self, wpath):
if wpath == '.hgignore':
self.update_hgignore()
try:
st = self.stat(wpath)
if stat.S_ISREG(st[0]):
if self.dirstate[wpath] in 'lmn':
self.updatefile(wpath, st)
except OSError:
pass
@eventaction('d')
def deleted(self, wpath):
if wpath == '.hgignore':
self.update_hgignore()
elif wpath.startswith('.hg/'):
if wpath == '.hg/wlock':
self.check_dirstate()
return
self.deletefile(wpath, self.dirstate[wpath])
def process_create(self, wpath, evt):
if self.ui.debugflag:
self.ui.note(_('%s event: created %s\n') %
(self.event_time(), wpath))
if evt.mask & inotify.IN_ISDIR:
self.scan(wpath)
else:
self.created(wpath)
def process_delete(self, wpath, evt):
if self.ui.debugflag:
self.ui.note(_('%s event: deleted %s\n') %
(self.event_time(), wpath))
if evt.mask & inotify.IN_ISDIR:
tree = self.tree.dir(wpath)
todelete = [wfn for wfn, ignore in tree.walk('?')]
for fn in todelete:
self.deletefile(fn, '?')
self.scan(wpath)
else:
self.deleted(wpath)
def process_modify(self, wpath, evt):
if self.ui.debugflag:
self.ui.note(_('%s event: modified %s\n') %
(self.event_time(), wpath))
if not (evt.mask & inotify.IN_ISDIR):
self.modified(wpath)
def process_unmount(self, evt):
self.ui.warn(_('filesystem containing %s was unmounted\n') %
evt.fullpath)
sys.exit(0)
def handle_pollevents(self, events):
if self.ui.debugflag:
self.ui.note(_('%s readable: %d bytes\n') %
(self.event_time(), self.threshold.readable()))
if not self.threshold():
if self.registered:
if self.ui.debugflag:
self.ui.note(_('%s below threshold - unhooking\n') %
(self.event_time()))
self.unregister()
self.timeout = 250
else:
self.read_events()
def read_events(self, bufsize=None):
events = self.watcher.read(bufsize)
if self.ui.debugflag:
self.ui.note(_('%s reading %d events\n') %
(self.event_time(), len(events)))
for evt in events:
assert evt.fullpath.startswith(self.wprefix)
wpath = evt.fullpath[self.prefixlen:]
# paths have been normalized, wpath never ends with a '/'
if wpath.startswith('.hg/') and evt.mask & inotify.IN_ISDIR:
# ignore subdirectories of .hg/ (merge, patches...)
continue
if evt.mask & inotify.IN_UNMOUNT:
self.process_unmount(wpath, evt)
elif evt.mask & (inotify.IN_MODIFY | inotify.IN_ATTRIB):
self.process_modify(wpath, evt)
elif evt.mask & (inotify.IN_DELETE | inotify.IN_DELETE_SELF |
inotify.IN_MOVED_FROM):
self.process_delete(wpath, evt)
elif evt.mask & (inotify.IN_CREATE | inotify.IN_MOVED_TO):
self.process_create(wpath, evt)
self.lastevent.clear()
def handle_timeout(self):
if not self.registered:
if self.ui.debugflag:
self.ui.note(_('%s hooking back up with %d bytes readable\n') %
(self.event_time(), self.threshold.readable()))
self.read_events(0)
self.register(timeout=None)
self.timeout = None
def shutdown(self):
self.watcher.close()
def debug(self):
"""
Returns a sorted list of relatives paths currently watched,
for debugging purposes.
"""
return sorted(tuple[0][self.prefixlen:] for tuple in self.watcher)
class server(pollable):
"""
Listens for client queries on unix socket inotify.sock
"""
def __init__(self, ui, root, repowatcher, timeout):
self.ui = ui
self.repowatcher = repowatcher
self.sock = socket.socket(socket.AF_UNIX)
self.sockpath = join(root, '.hg/inotify.sock')
self.realsockpath = None
try:
self.sock.bind(self.sockpath)
except socket.error, err:
if err[0] == errno.EADDRINUSE:
raise AlreadyStartedException(_('could not start server: %s')
% err[1])
if err[0] == "AF_UNIX path too long":
tempdir = tempfile.mkdtemp(prefix="hg-inotify-")
self.realsockpath = os.path.join(tempdir, "inotify.sock")
try:
self.sock.bind(self.realsockpath)
os.symlink(self.realsockpath, self.sockpath)
except (OSError, socket.error), inst:
try:
os.unlink(self.realsockpath)
except:
pass
os.rmdir(tempdir)
if inst.errno == errno.EEXIST:
raise AlreadyStartedException(_('could not start server: %s')
% inst.strerror)
raise
else:
raise
self.sock.listen(5)
self.fileno = self.sock.fileno
self.register(timeout=timeout)
def handle_timeout(self):
pass
def answer_stat_query(self, cs):
names = cs.read().split('\0')
states = names.pop()
self.ui.note(_('answering query for %r\n') % states)
if self.repowatcher.timeout:
# We got a query while a rescan is pending. Make sure we
# rescan before responding, or we could give back a wrong
# answer.
self.repowatcher.handle_timeout()
if not names:
def genresult(states, tree):
for fn, state in tree.walk(states):
yield fn
else:
def genresult(states, tree):
for fn in names:
for f in tree.lookup(states, fn):
yield f
return ['\0'.join(r) for r in [
genresult('l', self.repowatcher.statustrees['l']),
genresult('m', self.repowatcher.statustrees['m']),
genresult('a', self.repowatcher.statustrees['a']),
genresult('r', self.repowatcher.statustrees['r']),
genresult('!', self.repowatcher.statustrees['!']),
'?' in states
and genresult('?', self.repowatcher.statustrees['?'])
or [],
[],
'c' in states and genresult('n', self.repowatcher.tree) or [],
]]
def answer_dbug_query(self):
return ['\0'.join(self.repowatcher.debug())]
def handle_pollevents(self, events):
for e in events:
self.handle_pollevent()
def handle_pollevent(self):
sock, addr = self.sock.accept()
cs = common.recvcs(sock)
version = ord(cs.read(1))
if version != common.version:
self.ui.warn(_('received query from incompatible client '
'version %d\n') % version)
try:
# try to send back our version to the client
# this way, the client too is informed of the mismatch
sock.sendall(chr(common.version))
except:
pass
return
type = cs.read(4)
if type == 'STAT':
results = self.answer_stat_query(cs)
elif type == 'DBUG':
results = self.answer_dbug_query()
else:
self.ui.warn(_('unrecognized query type: %s\n') % type)
return
try:
try:
v = chr(common.version)
sock.sendall(v + type + struct.pack(common.resphdrfmts[type],
*map(len, results)))
sock.sendall(''.join(results))
finally:
sock.shutdown(socket.SHUT_WR)
except socket.error, err:
if err[0] != errno.EPIPE:
raise
def shutdown(self):
self.sock.close()
try:
os.unlink(self.sockpath)
if self.realsockpath:
os.unlink(self.realsockpath)
os.rmdir(os.path.dirname(self.realsockpath))
except OSError, err:
if err.errno != errno.ENOENT:
raise
class master(object):
def __init__(self, ui, dirstate, root, timeout=None):
self.ui = ui
self.repowatcher = repowatcher(ui, dirstate, root)
self.server = server(ui, root, self.repowatcher, timeout)
def shutdown(self):
for obj in pollable.instances.itervalues():
obj.shutdown()
def run(self):
self.repowatcher.setup()
self.ui.note(_('finished setup\n'))
if os.getenv('TIME_STARTUP'):
sys.exit(0)
pollable.run()
def start(ui, dirstate, root):
def closefds(ignore):
# (from python bug #1177468)
# close all inherited file descriptors
# Python 2.4.1 and later use /dev/urandom to seed the random module's RNG
# a file descriptor is kept internally as os._urandomfd (created on demand
# the first time os.urandom() is called), and should not be closed
try:
os.urandom(4)
urandom_fd = getattr(os, '_urandomfd', None)
except AttributeError:
urandom_fd = None
ignore.append(urandom_fd)
for fd in range(3, 256):
if fd in ignore:
continue
try:
os.close(fd)
except OSError:
pass
m = master(ui, dirstate, root)
sys.stdout.flush()
sys.stderr.flush()
pid = os.fork()
if pid:
return pid
closefds(pollable.instances.keys())
os.setsid()
fd = os.open('/dev/null', os.O_RDONLY)
os.dup2(fd, 0)
if fd > 0:
os.close(fd)
fd = os.open(ui.config('inotify', 'log', '/dev/null'),
os.O_RDWR | os.O_CREAT | os.O_TRUNC)
os.dup2(fd, 1)
os.dup2(fd, 2)
if fd > 2:
os.close(fd)
try:
m.run()
finally:
m.shutdown()
os._exit(0)