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# Copyright (C) 2006 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Basic server-side logic for dealing with requests."""
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from bzrlib import bzrdir, errors, registry, revision
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from bzrlib.bundle.serializer import write_bundle
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class SmartServerRequest(object):
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"""Base class for request handlers.
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def __init__(self, backing_transport):
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self._backing_transport = backing_transport
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def _check_enabled(self):
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"""Raises DisabledMethod if this method is disabled."""
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"""Mandatory extension point for SmartServerRequest subclasses.
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Subclasses must implement this.
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This should return a SmartServerResponse if this command expects to
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raise NotImplementedError(self.do)
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def execute(self, *args):
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"""Public entry point to execute this request.
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It will return a SmartServerResponse if the command does not expect a
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:param *args: the arguments of the request.
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def do_body(self, body_bytes):
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"""Called if the client sends a body with the request.
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Must return a SmartServerResponse.
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# TODO: if a client erroneously sends a request that shouldn't have a
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# body, what to do? Probably SmartServerRequestHandler should catch
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# this NotImplementedError and translate it into a 'bad request' error
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# to send to the client.
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raise NotImplementedError(self.do_body)
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class SmartServerResponse(object):
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"""Response generated by SmartServerRequestHandler."""
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def __init__(self, args, body=None):
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class SmartServerRequestHandler(object):
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"""Protocol logic for smart server.
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This doesn't handle serialization at all, it just processes requests and
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# IMPORTANT FOR IMPLEMENTORS: It is important that SmartServerRequestHandler
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# not contain encoding or decoding logic to allow the wire protocol to vary
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# from the object protocol: we will want to tweak the wire protocol separate
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# from the object model, and ideally we will be able to do that without
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# having a SmartServerRequestHandler subclass for each wire protocol, rather
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# just a Protocol subclass.
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# TODO: Better way of representing the body for commands that take it,
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# and allow it to be streamed into the server.
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def __init__(self, backing_transport, commands):
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:param backing_transport: a Transport to handle requests for.
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:param commands: a registry mapping command names to SmartServerRequest
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subclasses. e.g. bzrlib.transport.smart.vfs.vfs_commands.
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self._backing_transport = backing_transport
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self._commands = commands
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self._body_bytes = ''
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self.finished_reading = False
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def accept_body(self, bytes):
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"""Accept body data."""
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# TODO: This should be overriden for each command that desired body data
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# to handle the right format of that data, i.e. plain bytes, a bundle,
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# etc. The deserialisation into that format should be done in the
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# default fallback is to accumulate bytes.
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self._body_bytes += bytes
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def end_of_body(self):
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"""No more body data will be received."""
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self._run_handler_code(self._command.do_body, (self._body_bytes,), {})
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# cannot read after this.
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self.finished_reading = True
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def dispatch_command(self, cmd, args):
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"""Deprecated compatibility method.""" # XXX XXX
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command = self._commands.get(cmd)
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raise errors.SmartProtocolError("bad request %r" % (cmd,))
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self._command = command(self._backing_transport)
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self._run_handler_code(self._command.execute, args, {})
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def _run_handler_code(self, callable, args, kwargs):
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"""Run some handler specific code 'callable'.
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If a result is returned, it is considered to be the commands response,
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and finished_reading is set true, and its assigned to self.response.
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Any exceptions caught are translated and a response object created
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result = self._call_converting_errors(callable, args, kwargs)
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if result is not None:
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self.response = result
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self.finished_reading = True
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def _call_converting_errors(self, callable, args, kwargs):
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"""Call callable converting errors to Response objects."""
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# XXX: most of this error conversion is VFS-related, and thus ought to
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# be in SmartServerVFSRequestHandler somewhere.
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return callable(*args, **kwargs)
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except errors.NoSuchFile, e:
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return SmartServerResponse(('NoSuchFile', e.path))
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except errors.FileExists, e:
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return SmartServerResponse(('FileExists', e.path))
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except errors.DirectoryNotEmpty, e:
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return SmartServerResponse(('DirectoryNotEmpty', e.path))
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except errors.ShortReadvError, e:
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return SmartServerResponse(('ShortReadvError',
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e.path, str(e.offset), str(e.length), str(e.actual)))
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except UnicodeError, e:
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# If it is a DecodeError, than most likely we are starting
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# with a plain string
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str_or_unicode = e.object
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if isinstance(str_or_unicode, unicode):
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# XXX: UTF-8 might have \x01 (our seperator byte) in it. We
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# should escape it somehow.
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val = 'u:' + str_or_unicode.encode('utf-8')
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val = 's:' + str_or_unicode.encode('base64')
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# This handles UnicodeEncodeError or UnicodeDecodeError
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return SmartServerResponse((e.__class__.__name__,
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e.encoding, val, str(e.start), str(e.end), e.reason))
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except errors.TransportNotPossible, e:
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if e.msg == "readonly transport":
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return SmartServerResponse(('ReadOnlyError', ))
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class HelloRequest(SmartServerRequest):
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"""Answer a version request with my version."""
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return SmartServerResponse(('ok', '1'))
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class GetBundleRequest(SmartServerRequest):
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def do(self, path, revision_id):
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# open transport relative to our base
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t = self._backing_transport.clone(path)
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control, extra_path = bzrdir.BzrDir.open_containing_from_transport(t)
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repo = control.open_repository()
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tmpf = tempfile.TemporaryFile()
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base_revision = revision.NULL_REVISION
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write_bundle(repo, revision_id, base_revision, tmpf)
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return SmartServerResponse((), tmpf.read())
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request_handlers = registry.Registry()
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request_handlers.register_lazy(
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'append', 'bzrlib.smart.vfs', 'AppendRequest')
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request_handlers.register_lazy(
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'delete', 'bzrlib.smart.vfs', 'DeleteRequest')
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request_handlers.register_lazy(
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'get', 'bzrlib.smart.vfs', 'GetRequest')
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request_handlers.register_lazy(
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'get_bundle', 'bzrlib.smart.request', 'GetBundleRequest')
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request_handlers.register_lazy(
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'has', 'bzrlib.smart.vfs', 'HasRequest')
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request_handlers.register_lazy(
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'hello', 'bzrlib.smart.request', 'HelloRequest')
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request_handlers.register_lazy(
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'iter_files_recursive', 'bzrlib.smart.vfs', 'IterFilesRecursive')
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request_handlers.register_lazy(
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'list_dir', 'bzrlib.smart.vfs', 'ListDirRequest')
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request_handlers.register_lazy(
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'mkdir', 'bzrlib.smart.vfs', 'MkdirCommand')
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request_handlers.register_lazy(
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'move', 'bzrlib.smart.vfs', 'MoveCommand')
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request_handlers.register_lazy(
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'put', 'bzrlib.smart.vfs', 'PutCommand')
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request_handlers.register_lazy(
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'put_non_atomic', 'bzrlib.smart.vfs', 'PutNonAtomicCommand')
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request_handlers.register_lazy(
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'readv', 'bzrlib.smart.vfs', 'ReadvCommand')
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request_handlers.register_lazy(
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'rename', 'bzrlib.smart.vfs', 'RenameCommand')
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request_handlers.register_lazy(
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'rmdir', 'bzrlib.smart.vfs', 'RmdirCommand')
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request_handlers.register_lazy(
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'stat', 'bzrlib.smart.vfs', 'StatCommand')