Mercurial > hg
view mercurial/sshpeer.py @ 32151:4d504e541d3d
rebase: use matcher to optimize manifestmerge
The old merge code would call manifestmerge and calculate the complete diff
between the source to the destination. In many cases, like rebase, the vast
majority of differences between the source and destination are irrelevant
because they are differences between the destination and the common ancestor
only, and therefore don't affect the merge. Since most actions are 'keep', all
the effort to compute them is wasted.
Instead, let's compute the difference between the source and the common ancestor
and only perform the diff of those files against the merge destination. When
using treemanifest, this lets us avoid loading almost the entire tree when
rebasing from a very old ancestor. This speeds up rebase of an old stack of 27
commits by 20x.
In mozilla-central, without treemanifest, when rebasing a commit from
default~100000 to default, this speeds up the manifestmerge step from 2.6s to
1.2s. However, the additional diff adds an overhead to all manifestmerge calls,
especially for flat manifests. When rebasing a commit from default~1 to default
it appears to add 100ms in mozilla-central. While we could put this optimization
behind a flag, I think the fact that it makes merge O(number of changes being
applied) instead of O(number of changes between X and Y) justifies it.
author | Durham Goode <durham@fb.com> |
---|---|
date | Wed, 03 May 2017 10:43:59 -0700 |
parents | ad6c5497cd15 |
children | 05906b8e1d23 f93975a5ebe8 |
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# sshpeer.py - ssh repository proxy class for mercurial # # Copyright 2005, 2006 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 re from .i18n import _ from . import ( error, util, wireproto, ) class remotelock(object): def __init__(self, repo): self.repo = repo def release(self): self.repo.unlock() self.repo = None def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): if self.repo: self.release() def __del__(self): if self.repo: self.release() def _serverquote(s): if not s: return s '''quote a string for the remote shell ... which we assume is sh''' if re.match('[a-zA-Z0-9@%_+=:,./-]*$', s): return s return "'%s'" % s.replace("'", "'\\''") def _forwardoutput(ui, pipe): """display all data currently available on pipe as remote output. This is non blocking.""" s = util.readpipe(pipe) if s: for l in s.splitlines(): ui.status(_("remote: "), l, '\n') class doublepipe(object): """Operate a side-channel pipe in addition of a main one The side-channel pipe contains server output to be forwarded to the user input. The double pipe will behave as the "main" pipe, but will ensure the content of the "side" pipe is properly processed while we wait for blocking call on the "main" pipe. If large amounts of data are read from "main", the forward will cease after the first bytes start to appear. This simplifies the implementation without affecting actual output of sshpeer too much as we rarely issue large read for data not yet emitted by the server. The main pipe is expected to be a 'bufferedinputpipe' from the util module that handle all the os specific bits. This class lives in this module because it focus on behavior specific to the ssh protocol.""" def __init__(self, ui, main, side): self._ui = ui self._main = main self._side = side def _wait(self): """wait until some data are available on main or side return a pair of boolean (ismainready, issideready) (This will only wait for data if the setup is supported by `util.poll`) """ if getattr(self._main, 'hasbuffer', False): # getattr for classic pipe return (True, True) # main has data, assume side is worth poking at. fds = [self._main.fileno(), self._side.fileno()] try: act = util.poll(fds) except NotImplementedError: # non supported yet case, assume all have data. act = fds return (self._main.fileno() in act, self._side.fileno() in act) def write(self, data): return self._call('write', data) def read(self, size): r = self._call('read', size) if size != 0 and not r: # We've observed a condition that indicates the # stdout closed unexpectedly. Check stderr one # more time and snag anything that's there before # letting anyone know the main part of the pipe # closed prematurely. _forwardoutput(self._ui, self._side) return r def readline(self): return self._call('readline') def _call(self, methname, data=None): """call <methname> on "main", forward output of "side" while blocking """ # data can be '' or 0 if (data is not None and not data) or self._main.closed: _forwardoutput(self._ui, self._side) return '' while True: mainready, sideready = self._wait() if sideready: _forwardoutput(self._ui, self._side) if mainready: meth = getattr(self._main, methname) if data is None: return meth() else: return meth(data) def close(self): return self._main.close() def flush(self): return self._main.flush() class sshpeer(wireproto.wirepeer): def __init__(self, ui, path, create=False): self._url = path self.ui = ui self.pipeo = self.pipei = self.pipee = None u = util.url(path, parsequery=False, parsefragment=False) if u.scheme != 'ssh' or not u.host or u.path is None: self._abort(error.RepoError(_("couldn't parse location %s") % path)) self.user = u.user if u.passwd is not None: self._abort(error.RepoError(_("password in URL not supported"))) self.host = u.host self.port = u.port self.path = u.path or "." sshcmd = self.ui.config("ui", "ssh", "ssh") remotecmd = self.ui.config("ui", "remotecmd", "hg") args = util.sshargs(sshcmd, _serverquote(self.host), _serverquote(self.user), _serverquote(self.port)) if create: cmd = '%s %s %s' % (sshcmd, args, util.shellquote("%s init %s" % (_serverquote(remotecmd), _serverquote(self.path)))) ui.debug('running %s\n' % cmd) res = ui.system(cmd, blockedtag='sshpeer') if res != 0: self._abort(error.RepoError(_("could not create remote repo"))) self._validaterepo(sshcmd, args, remotecmd) def url(self): return self._url def _validaterepo(self, sshcmd, args, remotecmd): # cleanup up previous run self.cleanup() cmd = '%s %s %s' % (sshcmd, args, util.shellquote("%s -R %s serve --stdio" % (_serverquote(remotecmd), _serverquote(self.path)))) self.ui.debug('running %s\n' % cmd) cmd = util.quotecommand(cmd) # while self.subprocess isn't used, having it allows the subprocess to # to clean up correctly later # # no buffer allow the use of 'select' # feel free to remove buffering and select usage when we ultimately # move to threading. sub = util.popen4(cmd, bufsize=0) self.pipeo, self.pipei, self.pipee, self.subprocess = sub self.pipei = util.bufferedinputpipe(self.pipei) self.pipei = doublepipe(self.ui, self.pipei, self.pipee) self.pipeo = doublepipe(self.ui, self.pipeo, self.pipee) # skip any noise generated by remote shell self._callstream("hello") r = self._callstream("between", pairs=("%s-%s" % ("0"*40, "0"*40))) lines = ["", "dummy"] max_noise = 500 while lines[-1] and max_noise: l = r.readline() self.readerr() if lines[-1] == "1\n" and l == "\n": break if l: self.ui.debug("remote: ", l) lines.append(l) max_noise -= 1 else: self._abort(error.RepoError(_('no suitable response from ' 'remote hg'))) self._caps = set() for l in reversed(lines): if l.startswith("capabilities:"): self._caps.update(l[:-1].split(":")[1].split()) break def _capabilities(self): return self._caps def readerr(self): _forwardoutput(self.ui, self.pipee) def _abort(self, exception): self.cleanup() raise exception def cleanup(self): if self.pipeo is None: return self.pipeo.close() self.pipei.close() try: # read the error descriptor until EOF for l in self.pipee: self.ui.status(_("remote: "), l) except (IOError, ValueError): pass self.pipee.close() __del__ = cleanup def _submitbatch(self, req): rsp = self._callstream("batch", cmds=wireproto.encodebatchcmds(req)) available = self._getamount() # TODO this response parsing is probably suboptimal for large # batches with large responses. toread = min(available, 1024) work = rsp.read(toread) available -= toread chunk = work while chunk: while ';' in work: one, work = work.split(';', 1) yield wireproto.unescapearg(one) toread = min(available, 1024) chunk = rsp.read(toread) available -= toread work += chunk yield wireproto.unescapearg(work) def _callstream(self, cmd, **args): self.ui.debug("sending %s command\n" % cmd) self.pipeo.write("%s\n" % cmd) _func, names = wireproto.commands[cmd] keys = names.split() wireargs = {} for k in keys: if k == '*': wireargs['*'] = args break else: wireargs[k] = args[k] del args[k] for k, v in sorted(wireargs.iteritems()): self.pipeo.write("%s %d\n" % (k, len(v))) if isinstance(v, dict): for dk, dv in v.iteritems(): self.pipeo.write("%s %d\n" % (dk, len(dv))) self.pipeo.write(dv) else: self.pipeo.write(v) self.pipeo.flush() return self.pipei def _callcompressable(self, cmd, **args): return self._callstream(cmd, **args) def _call(self, cmd, **args): self._callstream(cmd, **args) return self._recv() def _callpush(self, cmd, fp, **args): r = self._call(cmd, **args) if r: return '', r for d in iter(lambda: fp.read(4096), ''): self._send(d) self._send("", flush=True) r = self._recv() if r: return '', r return self._recv(), '' def _calltwowaystream(self, cmd, fp, **args): r = self._call(cmd, **args) if r: # XXX needs to be made better raise error.Abort(_('unexpected remote reply: %s') % r) for d in iter(lambda: fp.read(4096), ''): self._send(d) self._send("", flush=True) return self.pipei def _getamount(self): l = self.pipei.readline() if l == '\n': self.readerr() msg = _('check previous remote output') self._abort(error.OutOfBandError(hint=msg)) self.readerr() try: return int(l) except ValueError: self._abort(error.ResponseError(_("unexpected response:"), l)) def _recv(self): return self.pipei.read(self._getamount()) def _send(self, data, flush=False): self.pipeo.write("%d\n" % len(data)) if data: self.pipeo.write(data) if flush: self.pipeo.flush() self.readerr() def lock(self): self._call("lock") return remotelock(self) def unlock(self): self._call("unlock") def addchangegroup(self, cg, source, url, lock=None): '''Send a changegroup to the remote server. Return an integer similar to unbundle(). DEPRECATED, since it requires locking the remote.''' d = self._call("addchangegroup") if d: self._abort(error.RepoError(_("push refused: %s") % d)) for d in iter(lambda: cg.read(4096), ''): self.pipeo.write(d) self.readerr() self.pipeo.flush() self.readerr() r = self._recv() if not r: return 1 try: return int(r) except ValueError: self._abort(error.ResponseError(_("unexpected response:"), r)) instance = sshpeer