mercurial/sshserver.py

avoid calling (cd ...) with `nil' as a directory name

When (hg-root) cannot determine the current Mercurial root, print an
error message instead of trying to evaluate (cd nil).

# sshserver.py - ssh protocol server support for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from demandload import demandload
from i18n import gettext as _
from node import *
demandload(globals(), "os streamclone sys tempfile util")

class sshserver(object):
    def __init__(self, ui, repo):
        self.ui = ui
        self.repo = repo
        self.lock = None
        self.fin = sys.stdin
        self.fout = sys.stdout

        sys.stdout = sys.stderr

        # Prevent insertion/deletion of CRs
        util.set_binary(self.fin)
        util.set_binary(self.fout)

    def getarg(self):
        argline = self.fin.readline()[:-1]
        arg, l = argline.split()
        val = self.fin.read(int(l))
        return arg, val

    def respond(self, v):
        self.fout.write("%d\n" % len(v))
        self.fout.write(v)
        self.fout.flush()

    def serve_forever(self):
        while self.serve_one(): pass
        sys.exit(0)

    def serve_one(self):
        cmd = self.fin.readline()[:-1]
        if cmd:
            impl = getattr(self, 'do_' + cmd, None)
            if impl: impl()
            else: self.respond("")
        return cmd != ''

    def do_heads(self):
        h = self.repo.heads()
        self.respond(" ".join(map(hex, h)) + "\n")

    def do_hello(self):
        '''the hello command returns a set of lines describing various
        interesting things about the server, in an RFC822-like format.
        Currently the only one defined is "capabilities", which
        consists of a line in the form:

        capabilities: space separated list of tokens
        '''

        caps = ['unbundle']
        if self.ui.configbool('server', 'uncompressed'):
            caps.append('stream=%d' % self.repo.revlogversion)
        self.respond("capabilities: %s\n" % (' '.join(caps),))

    def do_lock(self):
        '''DEPRECATED - allowing remote client to lock repo is not safe'''

        self.lock = self.repo.lock()
        self.respond("")

    def do_unlock(self):
        '''DEPRECATED'''

        if self.lock:
            self.lock.release()
        self.lock = None
        self.respond("")

    def do_branches(self):
        arg, nodes = self.getarg()
        nodes = map(bin, nodes.split(" "))
        r = []
        for b in self.repo.branches(nodes):
            r.append(" ".join(map(hex, b)) + "\n")
        self.respond("".join(r))

    def do_between(self):
        arg, pairs = self.getarg()
        pairs = [map(bin, p.split("-")) for p in pairs.split(" ")]
        r = []
        for b in self.repo.between(pairs):
            r.append(" ".join(map(hex, b)) + "\n")
        self.respond("".join(r))

    def do_changegroup(self):
        nodes = []
        arg, roots = self.getarg()
        nodes = map(bin, roots.split(" "))

        cg = self.repo.changegroup(nodes, 'serve')
        while True:
            d = cg.read(4096)
            if not d:
                break
            self.fout.write(d)

        self.fout.flush()

    def do_addchangegroup(self):
        '''DEPRECATED'''

        if not self.lock:
            self.respond("not locked")
            return

        self.respond("")
        r = self.repo.addchangegroup(self.fin, 'serve', self.client_url())
        self.respond(str(r))

    def client_url(self):
        client = os.environ.get('SSH_CLIENT', '').split(' ', 1)[0]
        return 'remote:ssh:' + client
        
    def do_unbundle(self):
        their_heads = self.getarg()[1].split()

        def check_heads():
            heads = map(hex, self.repo.heads())
            return their_heads == [hex('force')] or their_heads == heads

        # fail early if possible
        if not check_heads():
            self.respond(_('unsynced changes'))
            return

        self.respond('')

        # write bundle data to temporary file because it can be big

        try:
            fd, tempname = tempfile.mkstemp(prefix='hg-unbundle-')
            fp = os.fdopen(fd, 'wb+')

            count = int(self.fin.readline())
            while count:
                fp.write(self.fin.read(count))
                count = int(self.fin.readline())

            was_locked = self.lock is not None
            if not was_locked:
                self.lock = self.repo.lock()
            try:
                if not check_heads():
                    # someone else committed/pushed/unbundled while we
                    # were transferring data
                    self.respond(_('unsynced changes'))
                    return
                self.respond('')

                # push can proceed

                fp.seek(0)
                r = self.repo.addchangegroup(fp, 'serve', self.client_url())
                self.respond(str(r))
            finally:
                if not was_locked:
                    self.lock.release()
                    self.lock = None
        finally:
            fp.close()
            os.unlink(tempname)

    def do_stream_out(self):
        streamclone.stream_out(self.repo, self.fout)