view hgext/inotify/client.py @ 13158:9e7e24052745

merge: fast-forward merge with descendant

issue2538 gives a case where a changeset is merged with its child (which is on
another branch), and to my surprise the result is a real merge with two
parents, not just a "fast forward" "merge" with only the child as parent.

That is essentially the same as issue619.

Is the existing behaviour as intended and correct?

Or is the following fix correct?

Some extra "created new head" pops up with this fix, but it seems to me like
they could be considered correct. The old branch head has been superseeded by
changes on the other branch, and when the changes on the other branch is merged
back to the branch it will introduce a new head not directly related to the
previous branch head.

(I guess the intention with existing behaviour could be to ensure that the
changesets on the branch are directly connected and that no new heads pops up
on merges.)

# client.py - inotify status client
#
# Copyright 2006, 2007, 2008 Bryan O'Sullivan <[e-mail]>
# Copyright 2007, 2008 Brendan Cully <[e-mail]>
# Copyright 2009 Nicolas Dumazet <[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 mercurial.i18n import _
import common, server
import errno, os, socket, struct

class QueryFailed(Exception):
    pass

def start_server(function):
    """
    Decorator.
    Tries to call function, if it fails, try to (re)start inotify server.
    Raise QueryFailed if something went wrong
    """
    def decorated_function(self, *args):
        try:
            return function(self, *args)
        except (OSError, socket.error), err:
            autostart = self.ui.configbool('inotify', 'autostart', True)

            if err.args[0] == errno.ECONNREFUSED:
                self.ui.warn(_('inotify-client: found dead inotify server '
                               'socket; removing it\n'))
                os.unlink(os.path.join(self.root, '.hg', 'inotify.sock'))
            if err.args[0] in (errno.ECONNREFUSED, errno.ENOENT) and autostart:
                try:
                    try:
                        server.start(self.ui, self.dirstate, self.root,
                                     dict(daemon=True, daemon_pipefds=''))
                    except server.AlreadyStartedException, inst:
                        # another process may have started its own
                        # inotify server while this one was starting.
                        self.ui.debug(str(inst))
                except Exception, inst:
                    self.ui.warn(_('inotify-client: could not start inotify '
                                   'server: %s\n') % inst)
                else:
                    try:
                        return function(self, *args)
                    except socket.error, err:
                        self.ui.warn(_('inotify-client: could not talk to new '
                                       'inotify server: %s\n') % err.args[-1])
            elif err.args[0] in (errno.ECONNREFUSED, errno.ENOENT):
                # silently ignore normal errors if autostart is False
                self.ui.debug('(inotify server not running)\n')
            else:
                self.ui.warn(_('inotify-client: failed to contact inotify '
                               'server: %s\n') % err.args[-1])

        self.ui.traceback()
        raise QueryFailed('inotify query failed')

    return decorated_function


class client(object):
    def __init__(self, ui, repo):
        self.ui = ui
        self.dirstate = repo.dirstate
        self.root = repo.root
        self.sock = socket.socket(socket.AF_UNIX)

    def _connect(self):
        sockpath = os.path.join(self.root, '.hg', 'inotify.sock')
        try:
            self.sock.connect(sockpath)
        except socket.error, err:
            if err.args[0] == "AF_UNIX path too long":
                sockpath = os.readlink(sockpath)
                self.sock.connect(sockpath)
            else:
                raise

    def _send(self, type, data):
        """Sends protocol version number, and the data"""
        self.sock.sendall(chr(common.version) + type + data)

        self.sock.shutdown(socket.SHUT_WR)

    def _receive(self, type):
        """
        Read data, check version number, extract headers,
        and returns a tuple (data descriptor, header)
        Raises QueryFailed on error
        """
        cs = common.recvcs(self.sock)
        try:
            version = ord(cs.read(1))
        except TypeError:
            # empty answer, assume the server crashed
            self.ui.warn(_('inotify-client: received empty answer from inotify '
                           'server'))
            raise QueryFailed('server crashed')

        if version != common.version:
            self.ui.warn(_('(inotify: received response from incompatible '
                      'server version %d)\n') % version)
            raise QueryFailed('incompatible server version')

        readtype = cs.read(4)
        if readtype != type:
            self.ui.warn(_('(inotify: received \'%s\' response when expecting'
                       ' \'%s\')\n') % (readtype, type))
            raise QueryFailed('wrong response type')

        hdrfmt = common.resphdrfmts[type]
        hdrsize = common.resphdrsizes[type]
        try:
            resphdr = struct.unpack(hdrfmt, cs.read(hdrsize))
        except struct.error:
            raise QueryFailed('unable to retrieve query response headers')

        return cs, resphdr

    def query(self, type, req):
        self._connect()

        self._send(type, req)

        return self._receive(type)

    @start_server
    def statusquery(self, names, match, ignored, clean, unknown=True):

        def genquery():
            for n in names:
                yield n
            states = 'almrx!'
            if ignored:
                raise ValueError('this is insanity')
            if clean:
                states += 'c'
            if unknown:
                states += '?'
            yield states

        req = '\0'.join(genquery())

        cs, resphdr = self.query('STAT', req)

        def readnames(nbytes):
            if nbytes:
                names = cs.read(nbytes)
                if names:
                    return filter(match, names.split('\0'))
            return []
        results = tuple(map(readnames, resphdr[:-1]))

        if names:
            nbytes = resphdr[-1]
            vdirs = cs.read(nbytes)
            if vdirs:
                for vdir in vdirs.split('\0'):
                    match.dir(vdir)

        return results

    @start_server
    def debugquery(self):
        cs, resphdr = self.query('DBUG', '')

        nbytes = resphdr[0]
        names = cs.read(nbytes)
        return names.split('\0')