view mercurial/sshrepo.py @ 12296:d7fff529d85d

clone: only use stream when we understand the revlog format

This patch fixes issues with stream cloning in the presense of parentdelta,
lwcopy and similar additions that change the interpretation of the revlog
format, or the format itself.

Currently, the stream capability is sent like this:
stream=<version of changelog>

But the client doesn't actually check the version number; also, it only checks
the changelog and it doesn't capture the interpretation-changes and
flag-changes in parentdelta and lwcopy.

This patch removes the 'stream' capability whenever we use a non-basic revlog
format, to prevent old clients from receiving incorrect data. In those cases,
a new capability called 'streamreqs' is added instead. Instead of a revlog
version, it comes with a list of revlog-format relevant requirements, which
are a subset of the repository requirements, excluding things that are not
relevant for stream.

New clients use this to determine whether or not they can stream. Old clients
only look for the 'stream' capability, as always. New servers will still send
this when serving old repositories.

# sshrepo.py - ssh repository proxy class for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import util, error, wireproto
import re

class remotelock(object):
    def __init__(self, repo):
        self.repo = repo
    def release(self):
        self.repo.unlock()
        self.repo = None
    def __del__(self):
        if self.repo:
            self.release()

class sshrepository(wireproto.wirerepository):
    def __init__(self, ui, path, create=0):
        self._url = path
        self.ui = ui

        m = re.match(r'^ssh://(([^@]+)@)?([^:/]+)(:(\d+))?(/(.*))?$', path)
        if not m:
            self._abort(error.RepoError(_("couldn't parse location %s") % path))

        self.user = m.group(2)
        self.host = m.group(3)
        self.port = m.group(5)
        self.path = m.group(7) or "."

        sshcmd = self.ui.config("ui", "ssh", "ssh")
        remotecmd = self.ui.config("ui", "remotecmd", "hg")

        args = util.sshargs(sshcmd, self.host, self.user, self.port)

        if create:
            cmd = '%s %s "%s init %s"'
            cmd = cmd % (sshcmd, args, remotecmd, self.path)

            ui.note(_('running %s\n') % cmd)
            res = util.system(cmd)
            if res != 0:
                self._abort(error.RepoError(_("could not create remote repo")))

        self.validate_repo(ui, sshcmd, args, remotecmd)

    def url(self):
        return self._url

    def validate_repo(self, ui, sshcmd, args, remotecmd):
        # cleanup up previous run
        self.cleanup()

        cmd = '%s %s "%s -R %s serve --stdio"'
        cmd = cmd % (sshcmd, args, remotecmd, self.path)

        cmd = util.quotecommand(cmd)
        ui.note(_('running %s\n') % cmd)
        self.pipeo, self.pipei, self.pipee = util.popen3(cmd)

        # 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:
                ui.debug("remote: ", l)
            lines.append(l)
            max_noise -= 1
        else:
            self._abort(error.RepoError(_("no suitable response from remote hg")))

        self.capabilities = set()
        for l in reversed(lines):
            if l.startswith("capabilities:"):
                self.capabilities.update(l[:-1].split(":")[1].split())
                break

    def readerr(self):
        while 1:
            size = util.fstat(self.pipee).st_size
            if size == 0:
                break
            l = self.pipee.readline()
            if not l:
                break
            self.ui.status(_("remote: "), l)

    def _abort(self, exception):
        self.cleanup()
        raise exception

    def cleanup(self):
        try:
            self.pipeo.close()
            self.pipei.close()
            # read the error descriptor until EOF
            for l in self.pipee:
                self.ui.status(_("remote: "), l)
            self.pipee.close()
        except:
            pass

    __del__ = cleanup

    def _callstream(self, cmd, **args):
        self.ui.debug("sending %s command\n" % cmd)
        self.pipeo.write("%s\n" % cmd)
        for k, v in sorted(args.iteritems()):
            self.pipeo.write("%s %d\n" % (k, len(v)))
            self.pipeo.write(v)
        self.pipeo.flush()

        return self.pipei

    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
        while 1:
            d = fp.read(4096)
            if not d:
                break
            self._send(d)
        self._send("", flush=True)
        r = self._recv()
        if r:
            return '', r
        return self._recv(), ''

    def _decompress(self, stream):
        return stream

    def _recv(self):
        l = self.pipei.readline()
        self.readerr()
        try:
            l = int(l)
        except:
            self._abort(error.ResponseError(_("unexpected response:"), l))
        return self.pipei.read(l)

    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):
        '''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))
        while 1:
            d = cg.read(4096)
            if not d:
                break
            self.pipeo.write(d)
            self.readerr()

        self.pipeo.flush()

        self.readerr()
        r = self._recv()
        if not r:
            return 1
        try:
            return int(r)
        except:
            self._abort(error.ResponseError(_("unexpected response:"), r))

instance = sshrepository