~bzr-pqm/bzr/bzr.dev

#! /usr/bin/env python

# Copyright (C) 2005 Canonical Ltd

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Proxy object for access to remote branches.

At the moment remote branches are only for HTTP and only for read

access.

"""

import gzip

from cStringIO import StringIO

import urllib2

from errors import BzrError, BzrCheckError

from branch import Branch, BZR_BRANCH_FORMAT

from trace import mutter

# velocitynet.com.au transparently proxies connections and thereby

# breaks keep-alive -- sucks!

ENABLE_URLGRABBER = True

if ENABLE_URLGRABBER:

    import urlgrabber

    import urlgrabber.keepalive

    urlgrabber.keepalive.DEBUG = 0

    def get_url(path, compressed=False):

        try:

            url = path

            if compressed:

                url += '.gz'

            mutter("grab url %s" % url)

            url_f = urlgrabber.urlopen(url, keepalive=1, close_connection=0)

            if not compressed:

                return url_f

            else:

                return gzip.GzipFile(fileobj=StringIO(url_f.read()))

        except urllib2.URLError, e:

            raise BzrError("remote fetch failed: %r: %s" % (url, e))

else:

    def get_url(url, compressed=False):

        import urllib2

        if compressed:

            url += '.gz'

        mutter("get_url %s" % url)

        url_f = urllib2.urlopen(url)

        if compressed:

            return gzip.GzipFile(fileobj=StringIO(url_f.read()))

        else:

            return url_f

def _find_remote_root(url):

    """Return the prefix URL that corresponds to the branch root."""

    orig_url = url

    while True:

        try:

            ff = get_url(url + '/.bzr/branch-format')

            fmt = ff.read()

            ff.close()

            fmt = fmt.rstrip('\r\n')

            if fmt != BZR_BRANCH_FORMAT.rstrip('\r\n'):

                raise BzrError("sorry, branch format %r not supported at url %s"

                               % (fmt, url))

            return url

        except urllib2.URLError:

            pass

        try:

            idx = url.rindex('/')

        except ValueError:

            raise BzrError('no branch root found for URL %s' % orig_url)

        url = url[:idx]        

class RemoteBranch(Branch):

    def __init__(self, baseurl, find_root=True):

        """Create new proxy for a remote branch."""

        if find_root:

            self.baseurl = _find_remote_root(baseurl)

        else:

            self.baseurl = baseurl

            self._check_format()

        self.inventory_store = RemoteStore(baseurl + '/.bzr/inventory-store/')

        self.text_store = RemoteStore(baseurl + '/.bzr/text-store/')

        self.revision_store = RemoteStore(baseurl + '/.bzr/revision-store/')

    def __str__(self):

        b = getattr(self, 'baseurl', 'undefined')

        return '%s(%r)' % (self.__class__.__name__, b)

    __repr__ = __str__

    def controlfile(self, filename, mode):

        if mode not in ('rb', 'rt', 'r'):

            raise BzrError("file mode %r not supported for remote branches" % mode)

        return get_url(self.baseurl + '/.bzr/' + filename, False)

    def lock_read(self):

        # no locking for remote branches yet

        pass

    def lock_write(self):

        from errors import LockError

        raise LockError("write lock not supported for remote branch %s"

                        % self.baseurl)

    def unlock(self):

        pass

    def relpath(self, path):

        if not path.startswith(self.baseurl):

            raise BzrError('path %r is not under base URL %r'

                           % (path, self.baseurl))

        pl = len(self.baseurl)

        return path[pl:].lstrip('/')

    def get_revision(self, revision_id):

        from bzrlib.revision import Revision

        from bzrlib.xml import unpack_xml

        revf = self.revision_store[revision_id]

        r = unpack_xml(Revision, revf)

        if r.revision_id != revision_id:

            raise BzrCheckError('revision stored as {%s} actually contains {%s}'

                                % (revision_id, r.revision_id))

        return r

class RemoteStore(object):

    def __init__(self, baseurl):

        self._baseurl = baseurl

    def _path(self, name):

        if '/' in name:

            raise ValueError('invalid store id', name)

        return self._baseurl + '/' + name

    def __getitem__(self, fileid):

        p = self._path(fileid)

        return get_url(p, compressed=True)