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# Copyright (C) 2006, 2007 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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"""Wire-level encoding and decoding of requests and responses for the smart
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from cStringIO import StringIO
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from bzrlib import debug
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from bzrlib import errors
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from bzrlib.smart import message, request
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from bzrlib.trace import log_exception_quietly, mutter
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from bzrlib.util.bencode import bdecode, bencode
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# Protocol version strings. These are sent as prefixes of bzr requests and
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# responses to identify the protocol version being used. (There are no version
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# one strings because that version doesn't send any).
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REQUEST_VERSION_TWO = 'bzr request 2\n'
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RESPONSE_VERSION_TWO = 'bzr response 2\n'
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MESSAGE_VERSION_THREE = 'bzr message 3 (bzr 1.6)\n'
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RESPONSE_VERSION_THREE = REQUEST_VERSION_THREE = MESSAGE_VERSION_THREE
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def _recv_tuple(from_file):
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req_line = from_file.readline()
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return _decode_tuple(req_line)
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def _decode_tuple(req_line):
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if req_line is None or req_line == '':
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if req_line[-1] != '\n':
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raise errors.SmartProtocolError("request %r not terminated" % req_line)
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return tuple(req_line[:-1].split('\x01'))
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def _encode_tuple(args):
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"""Encode the tuple args to a bytestream."""
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return '\x01'.join(args) + '\n'
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class Requester(object):
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"""Abstract base class for an object that can issue requests on a smart
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def call(self, *args):
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"""Make a remote call.
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:param args: the arguments of this call.
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raise NotImplementedError(self.call)
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def call_with_body_bytes(self, args, body):
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"""Make a remote call with a body.
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:param args: the arguments of this call.
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:param body: the body to send with the request.
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raise NotImplementedError(self.call_with_body_bytes)
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def call_with_body_readv_array(self, args, body):
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"""Make a remote call with a readv array.
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:param args: the arguments of this call.
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:type body: iterable of (start, length) tuples.
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:param body: the readv ranges to send with this request.
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raise NotImplementedError(self.call_with_body_readv_array)
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def set_headers(self, headers):
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raise NotImplementedError(self.set_headers)
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class SmartProtocolBase(object):
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"""Methods common to client and server"""
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# TODO: this only actually accomodates a single block; possibly should
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# support multiple chunks?
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def _encode_bulk_data(self, body):
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"""Encode body as a bulk data chunk."""
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return ''.join(('%d\n' % len(body), body, 'done\n'))
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def _serialise_offsets(self, offsets):
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"""Serialise a readv offset list."""
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for start, length in offsets:
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txt.append('%d,%d' % (start, length))
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return '\n'.join(txt)
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class SmartServerRequestProtocolOne(SmartProtocolBase):
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"""Server-side encoding and decoding logic for smart version 1."""
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def __init__(self, backing_transport, write_func, root_client_path='/'):
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self._backing_transport = backing_transport
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self._root_client_path = root_client_path
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self.unused_data = ''
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self._finished = False
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self._has_dispatched = False
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self._body_decoder = None
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self._write_func = write_func
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def accept_bytes(self, bytes):
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"""Take bytes, and advance the internal state machine appropriately.
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:param bytes: must be a byte string
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if not isinstance(bytes, str):
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raise ValueError(bytes)
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self.in_buffer += bytes
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if not self._has_dispatched:
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if '\n' not in self.in_buffer:
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# no command line yet
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self._has_dispatched = True
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first_line, self.in_buffer = self.in_buffer.split('\n', 1)
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req_args = _decode_tuple(first_line)
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self.request = request.SmartServerRequestHandler(
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self._backing_transport, commands=request.request_handlers,
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root_client_path=self._root_client_path)
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self.request.dispatch_command(req_args[0], req_args[1:])
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if self.request.finished_reading:
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self.unused_data = self.in_buffer
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self._send_response(self.request.response)
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except KeyboardInterrupt:
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except errors.UnknownSmartMethod, err:
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protocol_error = errors.SmartProtocolError(
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"bad request %r" % (err.verb,))
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failure = request.FailedSmartServerResponse(
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('error', str(protocol_error)))
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self._send_response(failure)
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except Exception, exception:
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# everything else: pass to client, flush, and quit
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log_exception_quietly()
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self._send_response(request.FailedSmartServerResponse(
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('error', str(exception))))
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if self._has_dispatched:
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# nothing to do.XXX: this routine should be a single state
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self.unused_data += self.in_buffer
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if self._body_decoder is None:
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self._body_decoder = LengthPrefixedBodyDecoder()
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self._body_decoder.accept_bytes(self.in_buffer)
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self.in_buffer = self._body_decoder.unused_data
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body_data = self._body_decoder.read_pending_data()
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self.request.accept_body(body_data)
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if self._body_decoder.finished_reading:
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self.request.end_of_body()
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if not self.request.finished_reading:
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raise AssertionError("no more body, request not finished")
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if self.request.response is not None:
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self._send_response(self.request.response)
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self.unused_data = self.in_buffer
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if self.request.finished_reading:
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raise AssertionError(
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"no response and we have finished reading.")
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def _send_response(self, response):
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"""Send a smart server response down the output stream."""
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raise AssertionError('response already sent')
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self._finished = True
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self._write_protocol_version()
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self._write_success_or_failure_prefix(response)
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self._write_func(_encode_tuple(args))
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if not isinstance(body, str):
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raise ValueError(body)
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bytes = self._encode_bulk_data(body)
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self._write_func(bytes)
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def _write_protocol_version(self):
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"""Write any prefixes this protocol requires.
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Version one doesn't send protocol versions.
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def _write_success_or_failure_prefix(self, response):
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"""Write the protocol specific success/failure prefix.
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For SmartServerRequestProtocolOne this is omitted but we
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call is_successful to ensure that the response is valid.
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response.is_successful()
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def next_read_size(self):
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if self._body_decoder is None:
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return self._body_decoder.next_read_size()
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class SmartServerRequestProtocolTwo(SmartServerRequestProtocolOne):
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r"""Version two of the server side of the smart protocol.
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This prefixes responses with the value of RESPONSE_VERSION_TWO.
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response_marker = RESPONSE_VERSION_TWO
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request_marker = REQUEST_VERSION_TWO
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def _write_success_or_failure_prefix(self, response):
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"""Write the protocol specific success/failure prefix."""
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if response.is_successful():
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self._write_func('success\n')
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self._write_func('failed\n')
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def _write_protocol_version(self):
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r"""Write any prefixes this protocol requires.
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Version two sends the value of RESPONSE_VERSION_TWO.
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self._write_func(self.response_marker)
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def _send_response(self, response):
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"""Send a smart server response down the output stream."""
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raise AssertionError('response already sent')
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self._finished = True
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self._write_protocol_version()
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self._write_success_or_failure_prefix(response)
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self._write_func(_encode_tuple(response.args))
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if response.body is not None:
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if not isinstance(response.body, str):
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raise AssertionError('body must be a str')
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if not (response.body_stream is None):
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raise AssertionError(
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'body_stream and body cannot both be set')
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bytes = self._encode_bulk_data(response.body)
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self._write_func(bytes)
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elif response.body_stream is not None:
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_send_stream(response.body_stream, self._write_func)
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def _send_stream(stream, write_func):
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write_func('chunked\n')
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_send_chunks(stream, write_func)
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def _send_chunks(stream, write_func):
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if isinstance(chunk, str):
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bytes = "%x\n%s" % (len(chunk), chunk)
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elif isinstance(chunk, request.FailedSmartServerResponse):
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_send_chunks(chunk.args, write_func)
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raise errors.BzrError(
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'Chunks must be str or FailedSmartServerResponse, got %r'
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class _NeedMoreBytes(Exception):
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"""Raise this inside a _StatefulDecoder to stop decoding until more bytes
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def __init__(self, count=None):
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:param count: the total number of bytes needed by the current state.
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May be None if the number of bytes needed is unknown.
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class _StatefulDecoder(object):
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"""Base class for writing state machines to decode byte streams.
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Subclasses should provide a self.state_accept attribute that accepts bytes
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and, if appropriate, updates self.state_accept to a different function.
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accept_bytes will call state_accept as often as necessary to make sure the
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state machine has progressed as far as possible before it returns.
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See ProtocolThreeDecoder for an example subclass.
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self.finished_reading = False
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self._in_buffer_list = []
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self._in_buffer_len = 0
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self.unused_data = ''
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self.bytes_left = None
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self._number_needed_bytes = None
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def _get_in_buffer(self):
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if len(self._in_buffer_list) == 1:
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return self._in_buffer_list[0]
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in_buffer = ''.join(self._in_buffer_list)
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if len(in_buffer) != self._in_buffer_len:
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raise AssertionError(
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"Length of buffer did not match expected value: %s != %s"
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% self._in_buffer_len, len(in_buffer))
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self._in_buffer_list = [in_buffer]
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def _get_in_bytes(self, count):
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"""Grab X bytes from the input_buffer.
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Callers should have already checked that self._in_buffer_len is >
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count. Note, this does not consume the bytes from the buffer. The
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caller will still need to call _get_in_buffer() and then
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_set_in_buffer() if they actually need to consume the bytes.
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# check if we can yield the bytes from just the first entry in our list
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if len(self._in_buffer_list) == 0:
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raise AssertionError('Callers must be sure we have buffered bytes'
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' before calling _get_in_bytes')
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if len(self._in_buffer_list[0]) > count:
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return self._in_buffer_list[0][:count]
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# We can't yield it from the first buffer, so collapse all buffers, and
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in_buf = self._get_in_buffer()
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return in_buf[:count]
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def _set_in_buffer(self, new_buf):
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if new_buf is not None:
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self._in_buffer_list = [new_buf]
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self._in_buffer_len = len(new_buf)
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self._in_buffer_list = []
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self._in_buffer_len = 0
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def accept_bytes(self, bytes):
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"""Decode as much of bytes as possible.
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If 'bytes' contains too much data it will be appended to
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finished_reading will be set when no more data is required. Further
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data will be appended to self.unused_data.
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# accept_bytes is allowed to change the state
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self._number_needed_bytes = None
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# lsprof puts a very large amount of time on this specific call for
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self._in_buffer_list.append(bytes)
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self._in_buffer_len += len(bytes)
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# Run the function for the current state.
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current_state = self.state_accept
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while current_state != self.state_accept:
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# The current state has changed. Run the function for the new
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# current state, so that it can:
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# - decode any unconsumed bytes left in a buffer, and
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# - signal how many more bytes are expected (via raising
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current_state = self.state_accept
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except _NeedMoreBytes, e:
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self._number_needed_bytes = e.count
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class ChunkedBodyDecoder(_StatefulDecoder):
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"""Decoder for chunked body data.
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This is very similar the HTTP's chunked encoding. See the description of
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streamed body data in `doc/developers/network-protocol.txt` for details.
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_StatefulDecoder.__init__(self)
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self.state_accept = self._state_accept_expecting_header
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self.chunk_in_progress = None
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self.chunks = collections.deque()
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self.error_in_progress = None
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def next_read_size(self):
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# Note: the shortest possible chunk is 2 bytes: '0\n', and the
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# end-of-body marker is 4 bytes: 'END\n'.
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if self.state_accept == self._state_accept_reading_chunk:
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# We're expecting more chunk content. So we're expecting at least
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# the rest of this chunk plus an END chunk.
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return self.bytes_left + 4
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elif self.state_accept == self._state_accept_expecting_length:
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if self._in_buffer_len == 0:
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# We're expecting a chunk length. There's at least two bytes
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# left: a digit plus '\n'.
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# We're in the middle of reading a chunk length. So there's at
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# least one byte left, the '\n' that terminates the length.
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elif self.state_accept == self._state_accept_reading_unused:
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elif self.state_accept == self._state_accept_expecting_header:
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return max(0, len('chunked\n') - self._in_buffer_len)
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raise AssertionError("Impossible state: %r" % (self.state_accept,))
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def read_next_chunk(self):
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return self.chunks.popleft()
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def _extract_line(self):
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in_buf = self._get_in_buffer()
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pos = in_buf.find('\n')
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# We haven't read a complete line yet, so request more bytes before
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raise _NeedMoreBytes(1)
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# Trim the prefix (including '\n' delimiter) from the _in_buffer.
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self._set_in_buffer(in_buf[pos+1:])
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self.unused_data = self._get_in_buffer()
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self._in_buffer_list = []
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self._in_buffer_len = 0
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self.state_accept = self._state_accept_reading_unused
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error_args = tuple(self.error_in_progress)
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self.chunks.append(request.FailedSmartServerResponse(error_args))
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self.error_in_progress = None
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self.finished_reading = True
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def _state_accept_expecting_header(self):
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prefix = self._extract_line()
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if prefix == 'chunked':
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self.state_accept = self._state_accept_expecting_length
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raise errors.SmartProtocolError(
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'Bad chunked body header: "%s"' % (prefix,))
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def _state_accept_expecting_length(self):
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prefix = self._extract_line()
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self.error_in_progress = []
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self._state_accept_expecting_length()
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elif prefix == 'END':
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# We've read the end-of-body marker.
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# Any further bytes are unused data, including the bytes left in
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self.bytes_left = int(prefix, 16)
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self.chunk_in_progress = ''
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self.state_accept = self._state_accept_reading_chunk
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def _state_accept_reading_chunk(self):
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in_buf = self._get_in_buffer()
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in_buffer_len = len(in_buf)
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self.chunk_in_progress += in_buf[:self.bytes_left]
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self._set_in_buffer(in_buf[self.bytes_left:])
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self.bytes_left -= in_buffer_len
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if self.bytes_left <= 0:
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# Finished with chunk
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self.bytes_left = None
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self.error_in_progress.append(self.chunk_in_progress)
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self.chunks.append(self.chunk_in_progress)
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self.chunk_in_progress = None
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self.state_accept = self._state_accept_expecting_length
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def _state_accept_reading_unused(self):
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self.unused_data += self._get_in_buffer()
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self._in_buffer_list = []
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class LengthPrefixedBodyDecoder(_StatefulDecoder):
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"""Decodes the length-prefixed bulk data."""
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_StatefulDecoder.__init__(self)
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self.state_accept = self._state_accept_expecting_length
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self.state_read = self._state_read_no_data
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self._trailer_buffer = ''
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def next_read_size(self):
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if self.bytes_left is not None:
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# Ideally we want to read all the remainder of the body and the
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return self.bytes_left + 5
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elif self.state_accept == self._state_accept_reading_trailer:
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# Just the trailer left
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return 5 - len(self._trailer_buffer)
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elif self.state_accept == self._state_accept_expecting_length:
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# There's still at least 6 bytes left ('\n' to end the length, plus
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# Reading excess data. Either way, 1 byte at a time is fine.
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def read_pending_data(self):
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"""Return any pending data that has been decoded."""
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return self.state_read()
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def _state_accept_expecting_length(self):
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in_buf = self._get_in_buffer()
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pos = in_buf.find('\n')
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self.bytes_left = int(in_buf[:pos])
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self._set_in_buffer(in_buf[pos+1:])
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self.state_accept = self._state_accept_reading_body
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self.state_read = self._state_read_body_buffer
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def _state_accept_reading_body(self):
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in_buf = self._get_in_buffer()
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self.bytes_left -= len(in_buf)
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self._set_in_buffer(None)
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if self.bytes_left <= 0:
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if self.bytes_left != 0:
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self._trailer_buffer = self._body[self.bytes_left:]
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self._body = self._body[:self.bytes_left]
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self.bytes_left = None
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self.state_accept = self._state_accept_reading_trailer
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def _state_accept_reading_trailer(self):
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self._trailer_buffer += self._get_in_buffer()
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self._set_in_buffer(None)
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# TODO: what if the trailer does not match "done\n"? Should this raise
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# a ProtocolViolation exception?
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if self._trailer_buffer.startswith('done\n'):
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self.unused_data = self._trailer_buffer[len('done\n'):]
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self.state_accept = self._state_accept_reading_unused
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self.finished_reading = True
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def _state_accept_reading_unused(self):
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self.unused_data += self._get_in_buffer()
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self._set_in_buffer(None)
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def _state_read_no_data(self):
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def _state_read_body_buffer(self):
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class SmartClientRequestProtocolOne(SmartProtocolBase, Requester,
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message.ResponseHandler):
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"""The client-side protocol for smart version 1."""
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def __init__(self, request):
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"""Construct a SmartClientRequestProtocolOne.
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:param request: A SmartClientMediumRequest to serialise onto and
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self._request = request
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self._body_buffer = None
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self._request_start_time = None
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self._last_verb = None
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def set_headers(self, headers):
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self._headers = dict(headers)
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def call(self, *args):
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if 'hpss' in debug.debug_flags:
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mutter('hpss call: %s', repr(args)[1:-1])
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if getattr(self._request._medium, 'base', None) is not None:
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mutter(' (to %s)', self._request._medium.base)
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self._request_start_time = time.time()
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self._write_args(args)
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self._request.finished_writing()
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self._last_verb = args[0]
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def call_with_body_bytes(self, args, body):
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"""Make a remote call of args with body bytes 'body'.
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After calling this, call read_response_tuple to find the result out.
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if 'hpss' in debug.debug_flags:
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mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
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if getattr(self._request._medium, '_path', None) is not None:
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mutter(' (to %s)', self._request._medium._path)
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mutter(' %d bytes', len(body))
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self._request_start_time = time.time()
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if 'hpssdetail' in debug.debug_flags:
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mutter('hpss body content: %s', body)
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self._write_args(args)
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bytes = self._encode_bulk_data(body)
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self._request.accept_bytes(bytes)
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self._request.finished_writing()
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self._last_verb = args[0]
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def call_with_body_readv_array(self, args, body):
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"""Make a remote call with a readv array.
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The body is encoded with one line per readv offset pair. The numbers in
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each pair are separated by a comma, and no trailing \n is emitted.
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if 'hpss' in debug.debug_flags:
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mutter('hpss call w/readv: %s', repr(args)[1:-1])
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if getattr(self._request._medium, '_path', None) is not None:
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mutter(' (to %s)', self._request._medium._path)
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self._request_start_time = time.time()
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self._write_args(args)
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readv_bytes = self._serialise_offsets(body)
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bytes = self._encode_bulk_data(readv_bytes)
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self._request.accept_bytes(bytes)
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self._request.finished_writing()
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if 'hpss' in debug.debug_flags:
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mutter(' %d bytes in readv request', len(readv_bytes))
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self._last_verb = args[0]
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def cancel_read_body(self):
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"""After expecting a body, a response code may indicate one otherwise.
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This method lets the domain client inform the protocol that no body
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will be transmitted. This is a terminal method: after calling it the
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protocol is not able to be used further.
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self._request.finished_reading()
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def _read_response_tuple(self):
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result = self._recv_tuple()
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if 'hpss' in debug.debug_flags:
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if self._request_start_time is not None:
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mutter(' result: %6.3fs %s',
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time.time() - self._request_start_time,
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self._request_start_time = None
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mutter(' result: %s', repr(result)[1:-1])
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def read_response_tuple(self, expect_body=False):
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"""Read a response tuple from the wire.
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This should only be called once.
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result = self._read_response_tuple()
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self._response_is_unknown_method(result)
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self._raise_args_if_error(result)
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self._request.finished_reading()
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def _raise_args_if_error(self, result_tuple):
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# Later protocol versions have an explicit flag in the protocol to say
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# if an error response is "failed" or not. In version 1 we don't have
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# that luxury. So here is a complete list of errors that can be
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# returned in response to existing version 1 smart requests. Responses
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# starting with these codes are always "failed" responses.
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'UnicodeEncodeError',
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'UnicodeDecodeError',
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'UnlockableTransport',
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if result_tuple[0] in v1_error_codes:
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self._request.finished_reading()
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raise errors.ErrorFromSmartServer(result_tuple)
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def _response_is_unknown_method(self, result_tuple):
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"""Raise UnexpectedSmartServerResponse if the response is an 'unknonwn
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method' response to the request.
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:param response: The response from a smart client call_expecting_body
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:param verb: The verb used in that call.
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:raises: UnexpectedSmartServerResponse
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if (result_tuple == ('error', "Generic bzr smart protocol error: "
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"bad request '%s'" % self._last_verb) or
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result_tuple == ('error', "Generic bzr smart protocol error: "
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"bad request u'%s'" % self._last_verb)):
734
# The response will have no body, so we've finished reading.
735
self._request.finished_reading()
736
raise errors.UnknownSmartMethod(self._last_verb)
738
def read_body_bytes(self, count=-1):
739
"""Read bytes from the body, decoding into a byte stream.
741
We read all bytes at once to ensure we've checked the trailer for
742
errors, and then feed the buffer back as read_body_bytes is called.
744
if self._body_buffer is not None:
745
return self._body_buffer.read(count)
746
_body_decoder = LengthPrefixedBodyDecoder()
748
while not _body_decoder.finished_reading:
749
bytes = self._request.read_bytes(_body_decoder.next_read_size())
751
# end of file encountered reading from server
752
raise errors.ConnectionReset(
753
"Connection lost while reading response body.")
754
_body_decoder.accept_bytes(bytes)
755
self._request.finished_reading()
756
self._body_buffer = StringIO(_body_decoder.read_pending_data())
757
# XXX: TODO check the trailer result.
758
if 'hpss' in debug.debug_flags:
759
mutter(' %d body bytes read',
760
len(self._body_buffer.getvalue()))
761
return self._body_buffer.read(count)
763
def _recv_tuple(self):
764
"""Receive a tuple from the medium request."""
765
return _decode_tuple(self._request.read_line())
767
def query_version(self):
768
"""Return protocol version number of the server."""
770
resp = self.read_response_tuple()
771
if resp == ('ok', '1'):
773
elif resp == ('ok', '2'):
776
raise errors.SmartProtocolError("bad response %r" % (resp,))
778
def _write_args(self, args):
779
self._write_protocol_version()
780
bytes = _encode_tuple(args)
781
self._request.accept_bytes(bytes)
783
def _write_protocol_version(self):
784
"""Write any prefixes this protocol requires.
786
Version one doesn't send protocol versions.
790
class SmartClientRequestProtocolTwo(SmartClientRequestProtocolOne):
791
"""Version two of the client side of the smart protocol.
793
This prefixes the request with the value of REQUEST_VERSION_TWO.
796
response_marker = RESPONSE_VERSION_TWO
797
request_marker = REQUEST_VERSION_TWO
799
def read_response_tuple(self, expect_body=False):
800
"""Read a response tuple from the wire.
802
This should only be called once.
804
version = self._request.read_line()
805
if version != self.response_marker:
806
self._request.finished_reading()
807
raise errors.UnexpectedProtocolVersionMarker(version)
808
response_status = self._request.read_line()
809
result = SmartClientRequestProtocolOne._read_response_tuple(self)
810
self._response_is_unknown_method(result)
811
if response_status == 'success\n':
812
self.response_status = True
814
self._request.finished_reading()
816
elif response_status == 'failed\n':
817
self.response_status = False
818
self._request.finished_reading()
819
raise errors.ErrorFromSmartServer(result)
821
raise errors.SmartProtocolError(
822
'bad protocol status %r' % response_status)
824
def _write_protocol_version(self):
825
"""Write any prefixes this protocol requires.
827
Version two sends the value of REQUEST_VERSION_TWO.
829
self._request.accept_bytes(self.request_marker)
831
def read_streamed_body(self):
832
"""Read bytes from the body, decoding into a byte stream.
834
# Read no more than 64k at a time so that we don't risk error 10055 (no
835
# buffer space available) on Windows.
836
_body_decoder = ChunkedBodyDecoder()
837
while not _body_decoder.finished_reading:
838
bytes = self._request.read_bytes(_body_decoder.next_read_size())
840
# end of file encountered reading from server
841
raise errors.ConnectionReset(
842
"Connection lost while reading streamed body.")
843
_body_decoder.accept_bytes(bytes)
844
for body_bytes in iter(_body_decoder.read_next_chunk, None):
845
if 'hpss' in debug.debug_flags and type(body_bytes) is str:
846
mutter(' %d byte chunk read',
849
self._request.finished_reading()
852
def build_server_protocol_three(backing_transport, write_func,
854
request_handler = request.SmartServerRequestHandler(
855
backing_transport, commands=request.request_handlers,
856
root_client_path=root_client_path)
857
responder = ProtocolThreeResponder(write_func)
858
message_handler = message.ConventionalRequestHandler(request_handler, responder)
859
return ProtocolThreeDecoder(message_handler)
862
class ProtocolThreeDecoder(_StatefulDecoder):
864
response_marker = RESPONSE_VERSION_THREE
865
request_marker = REQUEST_VERSION_THREE
867
def __init__(self, message_handler, expect_version_marker=False):
868
_StatefulDecoder.__init__(self)
869
self._has_dispatched = False
871
if expect_version_marker:
872
self.state_accept = self._state_accept_expecting_protocol_version
873
# We're expecting at least the protocol version marker + some
875
self._number_needed_bytes = len(MESSAGE_VERSION_THREE) + 4
877
self.state_accept = self._state_accept_expecting_headers
878
self._number_needed_bytes = 4
879
self.decoding_failed = False
880
self.request_handler = self.message_handler = message_handler
882
def accept_bytes(self, bytes):
883
self._number_needed_bytes = None
885
_StatefulDecoder.accept_bytes(self, bytes)
886
except KeyboardInterrupt:
888
except errors.SmartMessageHandlerError, exception:
889
# We do *not* set self.decoding_failed here. The message handler
890
# has raised an error, but the decoder is still able to parse bytes
891
# and determine when this message ends.
892
log_exception_quietly()
893
self.message_handler.protocol_error(exception.exc_value)
894
# The state machine is ready to continue decoding, but the
895
# exception has interrupted the loop that runs the state machine.
896
# So we call accept_bytes again to restart it.
897
self.accept_bytes('')
898
except Exception, exception:
899
# The decoder itself has raised an exception. We cannot continue
901
self.decoding_failed = True
902
if isinstance(exception, errors.UnexpectedProtocolVersionMarker):
903
# This happens during normal operation when the client tries a
904
# protocol version the server doesn't understand, so no need to
905
# log a traceback every time.
906
# Note that this can only happen when
907
# expect_version_marker=True, which is only the case on the
911
log_exception_quietly()
912
self.message_handler.protocol_error(exception)
914
def _extract_length_prefixed_bytes(self):
915
if self._in_buffer_len < 4:
916
# A length prefix by itself is 4 bytes, and we don't even have that
918
raise _NeedMoreBytes(4)
919
(length,) = struct.unpack('!L', self._get_in_bytes(4))
920
end_of_bytes = 4 + length
921
if self._in_buffer_len < end_of_bytes:
922
# We haven't yet read as many bytes as the length-prefix says there
924
raise _NeedMoreBytes(end_of_bytes)
925
# Extract the bytes from the buffer.
926
in_buf = self._get_in_buffer()
927
bytes = in_buf[4:end_of_bytes]
928
self._set_in_buffer(in_buf[end_of_bytes:])
931
def _extract_prefixed_bencoded_data(self):
932
prefixed_bytes = self._extract_length_prefixed_bytes()
934
decoded = bdecode(prefixed_bytes)
936
raise errors.SmartProtocolError(
937
'Bytes %r not bencoded' % (prefixed_bytes,))
940
def _extract_single_byte(self):
941
if self._in_buffer_len == 0:
942
# The buffer is empty
943
raise _NeedMoreBytes(1)
944
in_buf = self._get_in_buffer()
946
self._set_in_buffer(in_buf[1:])
949
def _state_accept_expecting_protocol_version(self):
950
needed_bytes = len(MESSAGE_VERSION_THREE) - self._in_buffer_len
951
in_buf = self._get_in_buffer()
953
# We don't have enough bytes to check if the protocol version
954
# marker is right. But we can check if it is already wrong by
955
# checking that the start of MESSAGE_VERSION_THREE matches what
957
# [In fact, if the remote end isn't bzr we might never receive
958
# len(MESSAGE_VERSION_THREE) bytes. So if the bytes we have so far
959
# are wrong then we should just raise immediately rather than
961
if not MESSAGE_VERSION_THREE.startswith(in_buf):
962
# We have enough bytes to know the protocol version is wrong
963
raise errors.UnexpectedProtocolVersionMarker(in_buf)
964
raise _NeedMoreBytes(len(MESSAGE_VERSION_THREE))
965
if not in_buf.startswith(MESSAGE_VERSION_THREE):
966
raise errors.UnexpectedProtocolVersionMarker(in_buf)
967
self._set_in_buffer(in_buf[len(MESSAGE_VERSION_THREE):])
968
self.state_accept = self._state_accept_expecting_headers
970
def _state_accept_expecting_headers(self):
971
decoded = self._extract_prefixed_bencoded_data()
972
if type(decoded) is not dict:
973
raise errors.SmartProtocolError(
974
'Header object %r is not a dict' % (decoded,))
975
self.state_accept = self._state_accept_expecting_message_part
977
self.message_handler.headers_received(decoded)
979
raise errors.SmartMessageHandlerError(sys.exc_info())
981
def _state_accept_expecting_message_part(self):
982
message_part_kind = self._extract_single_byte()
983
if message_part_kind == 'o':
984
self.state_accept = self._state_accept_expecting_one_byte
985
elif message_part_kind == 's':
986
self.state_accept = self._state_accept_expecting_structure
987
elif message_part_kind == 'b':
988
self.state_accept = self._state_accept_expecting_bytes
989
elif message_part_kind == 'e':
992
raise errors.SmartProtocolError(
993
'Bad message kind byte: %r' % (message_part_kind,))
995
def _state_accept_expecting_one_byte(self):
996
byte = self._extract_single_byte()
997
self.state_accept = self._state_accept_expecting_message_part
999
self.message_handler.byte_part_received(byte)
1001
raise errors.SmartMessageHandlerError(sys.exc_info())
1003
def _state_accept_expecting_bytes(self):
1004
# XXX: this should not buffer whole message part, but instead deliver
1005
# the bytes as they arrive.
1006
prefixed_bytes = self._extract_length_prefixed_bytes()
1007
self.state_accept = self._state_accept_expecting_message_part
1009
self.message_handler.bytes_part_received(prefixed_bytes)
1011
raise errors.SmartMessageHandlerError(sys.exc_info())
1013
def _state_accept_expecting_structure(self):
1014
structure = self._extract_prefixed_bencoded_data()
1015
self.state_accept = self._state_accept_expecting_message_part
1017
self.message_handler.structure_part_received(structure)
1019
raise errors.SmartMessageHandlerError(sys.exc_info())
1022
self.unused_data = self._get_in_buffer()
1023
self._set_in_buffer(None)
1024
self.state_accept = self._state_accept_reading_unused
1026
self.message_handler.end_received()
1028
raise errors.SmartMessageHandlerError(sys.exc_info())
1030
def _state_accept_reading_unused(self):
1031
self.unused_data = self._get_in_buffer()
1032
self._set_in_buffer(None)
1034
def next_read_size(self):
1035
if self.state_accept == self._state_accept_reading_unused:
1037
elif self.decoding_failed:
1038
# An exception occured while processing this message, probably from
1039
# self.message_handler. We're not sure that this state machine is
1040
# in a consistent state, so just signal that we're done (i.e. give
1044
if self._number_needed_bytes is not None:
1045
return self._number_needed_bytes - self._in_buffer_len
1047
raise AssertionError("don't know how many bytes are expected!")
1050
class _ProtocolThreeEncoder(object):
1052
response_marker = request_marker = MESSAGE_VERSION_THREE
1054
def __init__(self, write_func):
1056
self._real_write_func = write_func
1058
def _write_func(self, bytes):
1063
self._real_write_func(self._buf)
1066
def _serialise_offsets(self, offsets):
1067
"""Serialise a readv offset list."""
1069
for start, length in offsets:
1070
txt.append('%d,%d' % (start, length))
1071
return '\n'.join(txt)
1073
def _write_protocol_version(self):
1074
self._write_func(MESSAGE_VERSION_THREE)
1076
def _write_prefixed_bencode(self, structure):
1077
bytes = bencode(structure)
1078
self._write_func(struct.pack('!L', len(bytes)))
1079
self._write_func(bytes)
1081
def _write_headers(self, headers):
1082
self._write_prefixed_bencode(headers)
1084
def _write_structure(self, args):
1085
self._write_func('s')
1088
if type(arg) is unicode:
1089
utf8_args.append(arg.encode('utf8'))
1091
utf8_args.append(arg)
1092
self._write_prefixed_bencode(utf8_args)
1094
def _write_end(self):
1095
self._write_func('e')
1098
def _write_prefixed_body(self, bytes):
1099
self._write_func('b')
1100
self._write_func(struct.pack('!L', len(bytes)))
1101
self._write_func(bytes)
1103
def _write_error_status(self):
1104
self._write_func('oE')
1106
def _write_success_status(self):
1107
self._write_func('oS')
1110
class ProtocolThreeResponder(_ProtocolThreeEncoder):
1112
def __init__(self, write_func):
1113
_ProtocolThreeEncoder.__init__(self, write_func)
1114
self.response_sent = False
1115
self._headers = {'Software version': bzrlib.__version__}
1117
def send_error(self, exception):
1118
if self.response_sent:
1119
raise AssertionError(
1120
"send_error(%s) called, but response already sent."
1122
if isinstance(exception, errors.UnknownSmartMethod):
1123
failure = request.FailedSmartServerResponse(
1124
('UnknownMethod', exception.verb))
1125
self.send_response(failure)
1127
self.response_sent = True
1128
self._write_protocol_version()
1129
self._write_headers(self._headers)
1130
self._write_error_status()
1131
self._write_structure(('error', str(exception)))
1134
def send_response(self, response):
1135
if self.response_sent:
1136
raise AssertionError(
1137
"send_response(%r) called, but response already sent."
1139
self.response_sent = True
1140
self._write_protocol_version()
1141
self._write_headers(self._headers)
1142
if response.is_successful():
1143
self._write_success_status()
1145
self._write_error_status()
1146
self._write_structure(response.args)
1147
if response.body is not None:
1148
self._write_prefixed_body(response.body)
1149
elif response.body_stream is not None:
1150
for chunk in response.body_stream:
1151
self._write_prefixed_body(chunk)
1156
class ProtocolThreeRequester(_ProtocolThreeEncoder, Requester):
1158
def __init__(self, medium_request):
1159
_ProtocolThreeEncoder.__init__(self, medium_request.accept_bytes)
1160
self._medium_request = medium_request
1163
def set_headers(self, headers):
1164
self._headers = headers.copy()
1166
def call(self, *args):
1167
if 'hpss' in debug.debug_flags:
1168
mutter('hpss call: %s', repr(args)[1:-1])
1169
base = getattr(self._medium_request._medium, 'base', None)
1170
if base is not None:
1171
mutter(' (to %s)', base)
1172
self._request_start_time = time.time()
1173
self._write_protocol_version()
1174
self._write_headers(self._headers)
1175
self._write_structure(args)
1177
self._medium_request.finished_writing()
1179
def call_with_body_bytes(self, args, body):
1180
"""Make a remote call of args with body bytes 'body'.
1182
After calling this, call read_response_tuple to find the result out.
1184
if 'hpss' in debug.debug_flags:
1185
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
1186
path = getattr(self._medium_request._medium, '_path', None)
1187
if path is not None:
1188
mutter(' (to %s)', path)
1189
mutter(' %d bytes', len(body))
1190
self._request_start_time = time.time()
1191
self._write_protocol_version()
1192
self._write_headers(self._headers)
1193
self._write_structure(args)
1194
self._write_prefixed_body(body)
1196
self._medium_request.finished_writing()
1198
def call_with_body_readv_array(self, args, body):
1199
"""Make a remote call with a readv array.
1201
The body is encoded with one line per readv offset pair. The numbers in
1202
each pair are separated by a comma, and no trailing \n is emitted.
1204
if 'hpss' in debug.debug_flags:
1205
mutter('hpss call w/readv: %s', repr(args)[1:-1])
1206
path = getattr(self._medium_request._medium, '_path', None)
1207
if path is not None:
1208
mutter(' (to %s)', path)
1209
self._request_start_time = time.time()
1210
self._write_protocol_version()
1211
self._write_headers(self._headers)
1212
self._write_structure(args)
1213
readv_bytes = self._serialise_offsets(body)
1214
if 'hpss' in debug.debug_flags:
1215
mutter(' %d bytes in readv request', len(readv_bytes))
1216
self._write_prefixed_body(readv_bytes)
1218
self._medium_request.finished_writing()
added
removed
bzrlib/smart/protocol.py
