view mercurial/sshserver.py @ 9366:9ff178e7b627

tags: don't crash if unable to write tag cache

This happens with hgweb in real life, if the httpd user is unable to
write in the repository directory. Another case is doing 'hg incoming'
on a repository in the filesystem owned by someone else.

# sshserver.py - ssh protocol server support for mercurial
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

from i18n import _
from node import bin, hex
import streamclone, util, hook
import os, sys, tempfile, urllib

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

        hook.redirect(True)
        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):
        try:
            while self.serve_one(): pass
        finally:
            if self.lock is not None:
                self.lock.release()
        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_lookup(self):
        arg, key = self.getarg()
        assert arg == 'key'
        try:
            r = hex(self.repo.lookup(key))
            success = 1
        except Exception, inst:
            r = str(inst)
            success = 0
        self.respond("%s %s\n" % (success, r))

    def do_branchmap(self):
        branchmap = self.repo.branchmap()
        heads = []
        for branch, nodes in branchmap.iteritems():
            branchname = urllib.quote(branch)
            branchnodes = [hex(node) for node in nodes]
            heads.append('%s %s' % (branchname, ' '.join(branchnodes)))
        self.respond('\n'.join(heads))

    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', 'lookup', 'changegroupsubset', 'branchmap']
        if self.ui.configbool('server', 'uncompressed'):
            caps.append('stream=%d' % self.repo.changelog.version)
        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_changegroupsubset(self):
        argmap = dict([self.getarg(), self.getarg()])
        bases = [bin(n) for n in argmap['bases'].split(' ')]
        heads = [bin(n) for n in argmap['heads'].split(' ')]

        cg = self.repo.changegroupsubset(bases, heads, '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
        tempname = fp = None
        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:
            if fp is not None:
                fp.close()
            if tempname is not None:
                os.unlink(tempname)

    def do_stream_out(self):
        try:
            for chunk in streamclone.stream_out(self.repo):
                self.fout.write(chunk)
            self.fout.flush()
        except streamclone.StreamException, inst:
            self.fout.write(str(inst))
            self.fout.flush()