/brz/remove-bazaar

# Copyright (C) 2006, 2007 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

"""Basic server-side logic for dealing with requests."""

import tempfile

from bzrlib import (

    bzrdir,

    errors,

    revision

    )

from bzrlib.bundle.serializer import write_bundle

class SmartServerResponse(object):

    """Response generated by SmartServerRequestHandler."""

    def __init__(self, args, body=None):

        self.args = args

        self.body = body

# XXX: TODO: Create a SmartServerRequestHandler which will take the responsibility

# for delivering the data for a request. This could be done with as the

# StreamServer, though that would create conflation between request and response

# which may be undesirable.

class SmartServerRequestHandler(object):

    """Protocol logic for smart server.

    This doesn't handle serialization at all, it just processes requests and

    creates responses.

    """

    # IMPORTANT FOR IMPLEMENTORS: It is important that SmartServerRequestHandler

    # not contain encoding or decoding logic to allow the wire protocol to vary

    # from the object protocol: we will want to tweak the wire protocol separate

    # from the object model, and ideally we will be able to do that without

    # having a SmartServerRequestHandler subclass for each wire protocol, rather

    # just a Protocol subclass.

    # TODO: Better way of representing the body for commands that take it,

    # and allow it to be streamed into the server.

    def __init__(self, backing_transport):

        self._backing_transport = backing_transport

        self._converted_command = False

        self.finished_reading = False

        self._body_bytes = ''

        self.response = None

    def accept_body(self, bytes):

        """Accept body data.

        This should be overriden for each command that desired body data to

        handle the right format of that data. I.e. plain bytes, a bundle etc.

        The deserialisation into that format should be done in the Protocol

        object. Set self.desired_body_format to the format your method will

        handle.

        """

        # default fallback is to accumulate bytes.

        self._body_bytes += bytes

    def _end_of_body_handler(self):

        """An unimplemented end of body handler."""

        raise NotImplementedError(self._end_of_body_handler)

    def do_hello(self):

        """Answer a version request with my version."""

        return SmartServerResponse(('ok', '1'))

    def do_has(self, relpath):

        r = self._backing_transport.has(relpath) and 'yes' or 'no'

        return SmartServerResponse((r,))

    def do_get(self, relpath):

        backing_bytes = self._backing_transport.get_bytes(relpath)

        return SmartServerResponse(('ok',), backing_bytes)

    def _deserialise_optional_mode(self, mode):

        # XXX: FIXME this should be on the protocol object.

        if mode == '':

            return None

        else:

            return int(mode)

    def do_append(self, relpath, mode):

        self._converted_command = True

        self._relpath = relpath

        self._mode = self._deserialise_optional_mode(mode)

        self._end_of_body_handler = self._handle_do_append_end

    def _handle_do_append_end(self):

        old_length = self._backing_transport.append_bytes(

            self._relpath, self._body_bytes, self._mode)

        self.response = SmartServerResponse(('appended', '%d' % old_length))

    def do_delete(self, relpath):

        self._backing_transport.delete(relpath)

    def do_iter_files_recursive(self, relpath):

        transport = self._backing_transport.clone(relpath)

        filenames = transport.iter_files_recursive()

        return SmartServerResponse(('names',) + tuple(filenames))

    def do_list_dir(self, relpath):

        filenames = self._backing_transport.list_dir(relpath)

        return SmartServerResponse(('names',) + tuple(filenames))

    def do_mkdir(self, relpath, mode):

        self._backing_transport.mkdir(relpath,

                                      self._deserialise_optional_mode(mode))

    def do_move(self, rel_from, rel_to):

        self._backing_transport.move(rel_from, rel_to)

    def do_put(self, relpath, mode):

        self._converted_command = True

        self._relpath = relpath

        self._mode = self._deserialise_optional_mode(mode)

        self._end_of_body_handler = self._handle_do_put

    def _handle_do_put(self):

        self._backing_transport.put_bytes(self._relpath,

                self._body_bytes, self._mode)

        self.response = SmartServerResponse(('ok',))

    def _deserialise_offsets(self, text):

        # XXX: FIXME this should be on the protocol object.

        offsets = []

        for line in text.split('\n'):

            if not line:

                continue

            start, length = line.split(',')

            offsets.append((int(start), int(length)))

        return offsets

    def do_put_non_atomic(self, relpath, mode, create_parent, dir_mode):

        self._converted_command = True

        self._end_of_body_handler = self._handle_put_non_atomic

        self._relpath = relpath

        self._dir_mode = self._deserialise_optional_mode(dir_mode)

        self._mode = self._deserialise_optional_mode(mode)

        # a boolean would be nicer XXX

        self._create_parent = (create_parent == 'T')

    def _handle_put_non_atomic(self):

        self._backing_transport.put_bytes_non_atomic(self._relpath,

                self._body_bytes,

                mode=self._mode,

                create_parent_dir=self._create_parent,

                dir_mode=self._dir_mode)

        self.response = SmartServerResponse(('ok',))

    def do_readv(self, relpath):

        self._converted_command = True

        self._end_of_body_handler = self._handle_readv_offsets

        self._relpath = relpath

    def end_of_body(self):

        """No more body data will be received."""

        self._run_handler_code(self._end_of_body_handler, (), {})

        # cannot read after this.

        self.finished_reading = True

    def _handle_readv_offsets(self):

        """accept offsets for a readv request."""

        offsets = self._deserialise_offsets(self._body_bytes)

        backing_bytes = ''.join(bytes for offset, bytes in

            self._backing_transport.readv(self._relpath, offsets))

        self.response = SmartServerResponse(('readv',), backing_bytes)

    def do_rename(self, rel_from, rel_to):

        self._backing_transport.rename(rel_from, rel_to)

    def do_rmdir(self, relpath):

        self._backing_transport.rmdir(relpath)

    def do_stat(self, relpath):

        stat = self._backing_transport.stat(relpath)

        return SmartServerResponse(('stat', str(stat.st_size), oct(stat.st_mode)))

    def do_get_bundle(self, path, revision_id):

        # open transport relative to our base

        t = self._backing_transport.clone(path)

        control, extra_path = bzrdir.BzrDir.open_containing_from_transport(t)

        repo = control.open_repository()

        tmpf = tempfile.TemporaryFile()

        base_revision = revision.NULL_REVISION

        write_bundle(repo, revision_id, base_revision, tmpf)

        tmpf.seek(0)

        return SmartServerResponse((), tmpf.read())

    def dispatch_command(self, cmd, args):

        """Deprecated compatibility method.""" # XXX XXX

        func = getattr(self, 'do_' + cmd, None)

        if func is None:

            raise errors.SmartProtocolError("bad request %r" % (cmd,))

        self._run_handler_code(func, args, {})

    def _run_handler_code(self, callable, args, kwargs):

        """Run some handler specific code 'callable'.

        If a result is returned, it is considered to be the commands response,

        and finished_reading is set true, and its assigned to self.response.

        Any exceptions caught are translated and a response object created

        from them.

        """

        result = self._call_converting_errors(callable, args, kwargs)

        if result is not None:

            self.response = result

            self.finished_reading = True

        # handle unconverted commands

        if not self._converted_command:

            self.finished_reading = True

            if result is None:

                self.response = SmartServerResponse(('ok',))

    def _call_converting_errors(self, callable, args, kwargs):

        """Call callable converting errors to Response objects."""

        try:

            return callable(*args, **kwargs)

        except errors.NoSuchFile, e:

            return SmartServerResponse(('NoSuchFile', e.path))

        except errors.FileExists, e:

            return SmartServerResponse(('FileExists', e.path))

        except errors.DirectoryNotEmpty, e:

            return SmartServerResponse(('DirectoryNotEmpty', e.path))

        except errors.ShortReadvError, e:

            return SmartServerResponse(('ShortReadvError',

                e.path, str(e.offset), str(e.length), str(e.actual)))

        except UnicodeError, e:

            # If it is a DecodeError, than most likely we are starting

            # with a plain string

            str_or_unicode = e.object

            if isinstance(str_or_unicode, unicode):

                # XXX: UTF-8 might have \x01 (our seperator byte) in it.  We

                # should escape it somehow.

                val = 'u:' + str_or_unicode.encode('utf-8')

            else:

                val = 's:' + str_or_unicode.encode('base64')

            # This handles UnicodeEncodeError or UnicodeDecodeError

            return SmartServerResponse((e.__class__.__name__,

                    e.encoding, val, str(e.start), str(e.end), e.reason))

        except errors.TransportNotPossible, e:

            if e.msg == "readonly transport":

                return SmartServerResponse(('ReadOnlyError', ))

            else:

                raise