Mercurial > hg
view mercurial/commandserver.py @ 40924:08cfa77d7288
wireprotov2: unify file revision collection and linknode derivation
The old mechanism for choosing which file revisions to send in the
haveparents=True case was buggy in multiple ways - the most severe
of which being that file revisions were excluded when they shouldn't
have been.
This commit unifies the logic for deriving the filenodes that will
be sent by the "filesdata" command. We now consistently read files
data from manifests. The "haveparents" argument now controls whether
we iterate ctx.files() or use the full manifest to derive relevant
files.
The logic here is still woefully lacking to fully support shallow
clones. It will require an API break to fully address. This commit
should at least make the server APIs emit proper data, which is
strictly better than before.
Differential Revision: https://phab.mercurial-scm.org/D5406
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 10 Dec 2018 18:55:08 +0000 |
parents | 2525faf4ecdb |
children | 042ed354b9eb |
line wrap: on
line source
# commandserver.py - communicate with Mercurial's API over a pipe # # Copyright Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import errno import gc import os import random import signal import socket import struct import traceback try: import selectors selectors.BaseSelector except ImportError: from .thirdparty import selectors2 as selectors from .i18n import _ from . import ( encoding, error, loggingutil, pycompat, util, vfs as vfsmod, ) from .utils import ( cborutil, procutil, ) class channeledoutput(object): """ Write data to out in the following format: data length (unsigned int), data """ def __init__(self, out, channel): self.out = out self.channel = channel @property def name(self): return '<%c-channel>' % self.channel def write(self, data): if not data: return # single write() to guarantee the same atomicity as the underlying file self.out.write(struct.pack('>cI', self.channel, len(data)) + data) self.out.flush() def __getattr__(self, attr): if attr in (r'isatty', r'fileno', r'tell', r'seek'): raise AttributeError(attr) return getattr(self.out, attr) class channeledmessage(object): """ Write encoded message and metadata to out in the following format: data length (unsigned int), encoded message and metadata, as a flat key-value dict. Each message should have 'type' attribute. Messages of unknown type should be ignored. """ # teach ui that write() can take **opts structured = True def __init__(self, out, channel, encodename, encodefn): self._cout = channeledoutput(out, channel) self.encoding = encodename self._encodefn = encodefn def write(self, data, **opts): opts = pycompat.byteskwargs(opts) if data is not None: opts[b'data'] = data self._cout.write(self._encodefn(opts)) def __getattr__(self, attr): return getattr(self._cout, attr) class channeledinput(object): """ Read data from in_. Requests for input are written to out in the following format: channel identifier - 'I' for plain input, 'L' line based (1 byte) how many bytes to send at most (unsigned int), The client replies with: data length (unsigned int), 0 meaning EOF data """ maxchunksize = 4 * 1024 def __init__(self, in_, out, channel): self.in_ = in_ self.out = out self.channel = channel @property def name(self): return '<%c-channel>' % self.channel def read(self, size=-1): if size < 0: # if we need to consume all the clients input, ask for 4k chunks # so the pipe doesn't fill up risking a deadlock size = self.maxchunksize s = self._read(size, self.channel) buf = s while s: s = self._read(size, self.channel) buf += s return buf else: return self._read(size, self.channel) def _read(self, size, channel): if not size: return '' assert size > 0 # tell the client we need at most size bytes self.out.write(struct.pack('>cI', channel, size)) self.out.flush() length = self.in_.read(4) length = struct.unpack('>I', length)[0] if not length: return '' else: return self.in_.read(length) def readline(self, size=-1): if size < 0: size = self.maxchunksize s = self._read(size, 'L') buf = s # keep asking for more until there's either no more or # we got a full line while s and s[-1] != '\n': s = self._read(size, 'L') buf += s return buf else: return self._read(size, 'L') def __iter__(self): return self def next(self): l = self.readline() if not l: raise StopIteration return l __next__ = next def __getattr__(self, attr): if attr in (r'isatty', r'fileno', r'tell', r'seek'): raise AttributeError(attr) return getattr(self.in_, attr) _messageencoders = { b'cbor': lambda v: b''.join(cborutil.streamencode(v)), } def _selectmessageencoder(ui): # experimental config: cmdserver.message-encodings encnames = ui.configlist(b'cmdserver', b'message-encodings') for n in encnames: f = _messageencoders.get(n) if f: return n, f raise error.Abort(b'no supported message encodings: %s' % b' '.join(encnames)) class server(object): """ Listens for commands on fin, runs them and writes the output on a channel based stream to fout. """ def __init__(self, ui, repo, fin, fout, prereposetups=None): self.cwd = encoding.getcwd() if repo: # the ui here is really the repo ui so take its baseui so we don't # end up with its local configuration self.ui = repo.baseui self.repo = repo self.repoui = repo.ui else: self.ui = ui self.repo = self.repoui = None self._prereposetups = prereposetups self.cdebug = channeledoutput(fout, 'd') self.cerr = channeledoutput(fout, 'e') self.cout = channeledoutput(fout, 'o') self.cin = channeledinput(fin, fout, 'I') self.cresult = channeledoutput(fout, 'r') if self.ui.config(b'cmdserver', b'log') == b'-': # switch log stream of server's ui to the 'd' (debug) channel # (don't touch repo.ui as its lifetime is longer than the server) self.ui = self.ui.copy() setuplogging(self.ui, repo=None, fp=self.cdebug) # TODO: add this to help/config.txt when stabilized # ``channel`` # Use separate channel for structured output. (Command-server only) self.cmsg = None if ui.config(b'ui', b'message-output') == b'channel': encname, encfn = _selectmessageencoder(ui) self.cmsg = channeledmessage(fout, b'm', encname, encfn) self.client = fin def cleanup(self): """release and restore resources taken during server session""" def _read(self, size): if not size: return '' data = self.client.read(size) # is the other end closed? if not data: raise EOFError return data def _readstr(self): """read a string from the channel format: data length (uint32), data """ length = struct.unpack('>I', self._read(4))[0] if not length: return '' return self._read(length) def _readlist(self): """read a list of NULL separated strings from the channel""" s = self._readstr() if s: return s.split('\0') else: return [] def runcommand(self): """ reads a list of \0 terminated arguments, executes and writes the return code to the result channel """ from . import dispatch # avoid cycle args = self._readlist() # copy the uis so changes (e.g. --config or --verbose) don't # persist between requests copiedui = self.ui.copy() uis = [copiedui] if self.repo: self.repo.baseui = copiedui # clone ui without using ui.copy because this is protected repoui = self.repoui.__class__(self.repoui) repoui.copy = copiedui.copy # redo copy protection uis.append(repoui) self.repo.ui = self.repo.dirstate._ui = repoui self.repo.invalidateall() for ui in uis: ui.resetstate() # any kind of interaction must use server channels, but chg may # replace channels by fully functional tty files. so nontty is # enforced only if cin is a channel. if not util.safehasattr(self.cin, 'fileno'): ui.setconfig('ui', 'nontty', 'true', 'commandserver') req = dispatch.request(args[:], copiedui, self.repo, self.cin, self.cout, self.cerr, self.cmsg, prereposetups=self._prereposetups) try: ret = dispatch.dispatch(req) & 255 self.cresult.write(struct.pack('>i', int(ret))) finally: # restore old cwd if '--cwd' in args: os.chdir(self.cwd) def getencoding(self): """ writes the current encoding to the result channel """ self.cresult.write(encoding.encoding) def serveone(self): cmd = self.client.readline()[:-1] if cmd: handler = self.capabilities.get(cmd) if handler: handler(self) else: # clients are expected to check what commands are supported by # looking at the servers capabilities raise error.Abort(_('unknown command %s') % cmd) return cmd != '' capabilities = {'runcommand': runcommand, 'getencoding': getencoding} def serve(self): hellomsg = 'capabilities: ' + ' '.join(sorted(self.capabilities)) hellomsg += '\n' hellomsg += 'encoding: ' + encoding.encoding hellomsg += '\n' if self.cmsg: hellomsg += 'message-encoding: %s\n' % self.cmsg.encoding hellomsg += 'pid: %d' % procutil.getpid() if util.safehasattr(os, 'getpgid'): hellomsg += '\n' hellomsg += 'pgid: %d' % os.getpgid(0) # write the hello msg in -one- chunk self.cout.write(hellomsg) try: while self.serveone(): pass except EOFError: # we'll get here if the client disconnected while we were reading # its request return 1 return 0 def setuplogging(ui, repo=None, fp=None): """Set up server logging facility If cmdserver.log is '-', log messages will be sent to the given fp. It should be the 'd' channel while a client is connected, and otherwise is the stderr of the server process. """ # developer config: cmdserver.log logpath = ui.config(b'cmdserver', b'log') if not logpath: return # developer config: cmdserver.track-log tracked = set(ui.configlist(b'cmdserver', b'track-log')) if logpath == b'-' and fp: logger = loggingutil.fileobjectlogger(fp, tracked) elif logpath == b'-': logger = loggingutil.fileobjectlogger(ui.ferr, tracked) else: logpath = os.path.abspath(util.expandpath(logpath)) # developer config: cmdserver.max-log-files maxfiles = ui.configint(b'cmdserver', b'max-log-files') # developer config: cmdserver.max-log-size maxsize = ui.configbytes(b'cmdserver', b'max-log-size') vfs = vfsmod.vfs(os.path.dirname(logpath)) logger = loggingutil.filelogger(vfs, os.path.basename(logpath), tracked, maxfiles=maxfiles, maxsize=maxsize) targetuis = {ui} if repo: targetuis.add(repo.baseui) targetuis.add(repo.ui) for u in targetuis: u.setlogger(b'cmdserver', logger) class pipeservice(object): def __init__(self, ui, repo, opts): self.ui = ui self.repo = repo def init(self): pass def run(self): ui = self.ui # redirect stdio to null device so that broken extensions or in-process # hooks will never cause corruption of channel protocol. with procutil.protectedstdio(ui.fin, ui.fout) as (fin, fout): sv = server(ui, self.repo, fin, fout) try: return sv.serve() finally: sv.cleanup() def _initworkerprocess(): # use a different process group from the master process, in order to: # 1. make the current process group no longer "orphaned" (because the # parent of this process is in a different process group while # remains in a same session) # according to POSIX 2.2.2.52, orphaned process group will ignore # terminal-generated stop signals like SIGTSTP (Ctrl+Z), which will # cause trouble for things like ncurses. # 2. the client can use kill(-pgid, sig) to simulate terminal-generated # SIGINT (Ctrl+C) and process-exit-generated SIGHUP. our child # processes like ssh will be killed properly, without affecting # unrelated processes. os.setpgid(0, 0) # change random state otherwise forked request handlers would have a # same state inherited from parent. random.seed() def _serverequest(ui, repo, conn, createcmdserver, prereposetups): fin = conn.makefile(r'rb') fout = conn.makefile(r'wb') sv = None try: sv = createcmdserver(repo, conn, fin, fout, prereposetups) try: sv.serve() # handle exceptions that may be raised by command server. most of # known exceptions are caught by dispatch. except error.Abort as inst: ui.error(_('abort: %s\n') % inst) except IOError as inst: if inst.errno != errno.EPIPE: raise except KeyboardInterrupt: pass finally: sv.cleanup() except: # re-raises # also write traceback to error channel. otherwise client cannot # see it because it is written to server's stderr by default. if sv: cerr = sv.cerr else: cerr = channeledoutput(fout, 'e') cerr.write(encoding.strtolocal(traceback.format_exc())) raise finally: fin.close() try: fout.close() # implicit flush() may cause another EPIPE except IOError as inst: if inst.errno != errno.EPIPE: raise class unixservicehandler(object): """Set of pluggable operations for unix-mode services Almost all methods except for createcmdserver() are called in the main process. You can't pass mutable resource back from createcmdserver(). """ pollinterval = None def __init__(self, ui): self.ui = ui def bindsocket(self, sock, address): util.bindunixsocket(sock, address) sock.listen(socket.SOMAXCONN) self.ui.status(_('listening at %s\n') % address) self.ui.flush() # avoid buffering of status message def unlinksocket(self, address): os.unlink(address) def shouldexit(self): """True if server should shut down; checked per pollinterval""" return False def newconnection(self): """Called when main process notices new connection""" def createcmdserver(self, repo, conn, fin, fout, prereposetups): """Create new command server instance; called in the process that serves for the current connection""" return server(self.ui, repo, fin, fout, prereposetups) class unixforkingservice(object): """ Listens on unix domain socket and forks server per connection """ def __init__(self, ui, repo, opts, handler=None): self.ui = ui self.repo = repo self.address = opts['address'] if not util.safehasattr(socket, 'AF_UNIX'): raise error.Abort(_('unsupported platform')) if not self.address: raise error.Abort(_('no socket path specified with --address')) self._servicehandler = handler or unixservicehandler(ui) self._sock = None self._oldsigchldhandler = None self._workerpids = set() # updated by signal handler; do not iterate self._socketunlinked = None def init(self): self._sock = socket.socket(socket.AF_UNIX) self._servicehandler.bindsocket(self._sock, self.address) if util.safehasattr(procutil, 'unblocksignal'): procutil.unblocksignal(signal.SIGCHLD) o = signal.signal(signal.SIGCHLD, self._sigchldhandler) self._oldsigchldhandler = o self._socketunlinked = False def _unlinksocket(self): if not self._socketunlinked: self._servicehandler.unlinksocket(self.address) self._socketunlinked = True def _cleanup(self): signal.signal(signal.SIGCHLD, self._oldsigchldhandler) self._sock.close() self._unlinksocket() # don't kill child processes as they have active clients, just wait self._reapworkers(0) def run(self): try: self._mainloop() finally: self._cleanup() def _mainloop(self): exiting = False h = self._servicehandler selector = selectors.DefaultSelector() selector.register(self._sock, selectors.EVENT_READ, self._acceptnewconnection) while True: if not exiting and h.shouldexit(): # clients can no longer connect() to the domain socket, so # we stop queuing new requests. # for requests that are queued (connect()-ed, but haven't been # accept()-ed), handle them before exit. otherwise, clients # waiting for recv() will receive ECONNRESET. self._unlinksocket() exiting = True try: events = selector.select(timeout=h.pollinterval) except OSError as inst: # selectors2 raises ETIMEDOUT if timeout exceeded while # handling signal interrupt. That's probably wrong, but # we can easily get around it. if inst.errno != errno.ETIMEDOUT: raise events = [] if not events: # only exit if we completed all queued requests if exiting: break continue for key, _mask in events: key.data(key.fileobj, selector) selector.close() def _acceptnewconnection(self, sock, selector): h = self._servicehandler try: conn, _addr = sock.accept() except socket.error as inst: if inst.args[0] == errno.EINTR: return raise pid = os.fork() if pid: try: self.ui.log(b'cmdserver', b'forked worker process (pid=%d)\n', pid) self._workerpids.add(pid) h.newconnection() finally: conn.close() # release handle in parent process else: try: selector.close() sock.close() self._runworker(conn) conn.close() os._exit(0) except: # never return, hence no re-raises try: self.ui.traceback(force=True) finally: os._exit(255) def _sigchldhandler(self, signal, frame): self._reapworkers(os.WNOHANG) def _reapworkers(self, options): while self._workerpids: try: pid, _status = os.waitpid(-1, options) except OSError as inst: if inst.errno == errno.EINTR: continue if inst.errno != errno.ECHILD: raise # no child processes at all (reaped by other waitpid()?) self._workerpids.clear() return if pid == 0: # no waitable child processes return self.ui.log(b'cmdserver', b'worker process exited (pid=%d)\n', pid) self._workerpids.discard(pid) def _runworker(self, conn): signal.signal(signal.SIGCHLD, self._oldsigchldhandler) _initworkerprocess() h = self._servicehandler try: _serverequest(self.ui, self.repo, conn, h.createcmdserver, prereposetups=None) # TODO: pass in hook functions finally: gc.collect() # trigger __del__ since worker process uses os._exit