Mercurial > hg
view mercurial/sshserver.py @ 31956:c13ff31818b0
ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
author | Bryan O'Sullivan <bryano@fb.com> |
---|---|
date | Tue, 11 Apr 2017 14:54:12 -0700 |
parents | a150173da1c1 |
children | 5326e4ef1dab |
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# sshserver.py - ssh protocol server support for mercurial # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.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 sys from .i18n import _ from . import ( encoding, error, hook, util, wireproto, ) class sshserver(wireproto.abstractserverproto): def __init__(self, ui, repo): self.ui = ui self.repo = repo self.lock = None self.fin = ui.fin self.fout = ui.fout self.name = 'ssh' hook.redirect(True) ui.fout = repo.ui.fout = ui.ferr # Prevent insertion/deletion of CRs util.setbinary(self.fin) util.setbinary(self.fout) def getargs(self, args): data = {} keys = args.split() for n in xrange(len(keys)): argline = self.fin.readline()[:-1] arg, l = argline.split() if arg not in keys: raise error.Abort(_("unexpected parameter %r") % arg) if arg == '*': star = {} for k in xrange(int(l)): argline = self.fin.readline()[:-1] arg, l = argline.split() val = self.fin.read(int(l)) star[arg] = val data['*'] = star else: val = self.fin.read(int(l)) data[arg] = val return [data[k] for k in keys] def getarg(self, name): return self.getargs(name)[0] def getfile(self, fpout): self.sendresponse('') count = int(self.fin.readline()) while count: fpout.write(self.fin.read(count)) count = int(self.fin.readline()) def redirect(self): pass def sendresponse(self, v): self.fout.write("%d\n" % len(v)) self.fout.write(v) self.fout.flush() def sendstream(self, source): write = self.fout.write if source.reader: gen = iter(lambda: source.reader.read(4096), '') else: gen = source.gen for chunk in gen: write(chunk) self.fout.flush() def sendpushresponse(self, rsp): self.sendresponse('') self.sendresponse(str(rsp.res)) def sendpusherror(self, rsp): self.sendresponse(rsp.res) def sendooberror(self, rsp): self.ui.ferr.write('%s\n-\n' % rsp.message) self.ui.ferr.flush() self.fout.write('\n') self.fout.flush() def serve_forever(self): try: while self.serve_one(): pass finally: if self.lock is not None: self.lock.release() sys.exit(0) handlers = { str: sendresponse, wireproto.streamres: sendstream, wireproto.pushres: sendpushresponse, wireproto.pusherr: sendpusherror, wireproto.ooberror: sendooberror, } def serve_one(self): cmd = self.fin.readline()[:-1] if cmd and cmd in wireproto.commands: rsp = wireproto.dispatch(self.repo, self, cmd) self.handlers[rsp.__class__](self, rsp) elif cmd: impl = getattr(self, 'do_' + cmd, None) if impl: r = impl() if r is not None: self.sendresponse(r) else: self.sendresponse("") return cmd != '' def _client(self): client = encoding.environ.get('SSH_CLIENT', '').split(' ', 1)[0] return 'remote:ssh:' + client