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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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.bencode import bdecode_as_tuple, 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 call_with_body_stream(self, args, stream):
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# Protocols v1 and v2 don't support body streams. So it's safe to
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# assume that a v1/v2 server doesn't support whatever method we're
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# trying to call with a body stream.
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self._request.finished_writing()
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self._request.finished_reading()
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raise errors.UnknownSmartMethod(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
735
:param verb: The verb used in that call.
736
:raises: UnexpectedSmartServerResponse
738
if (result_tuple == ('error', "Generic bzr smart protocol error: "
739
"bad request '%s'" % self._last_verb) or
740
result_tuple == ('error', "Generic bzr smart protocol error: "
741
"bad request u'%s'" % self._last_verb)):
742
# The response will have no body, so we've finished reading.
743
self._request.finished_reading()
744
raise errors.UnknownSmartMethod(self._last_verb)
746
def read_body_bytes(self, count=-1):
747
"""Read bytes from the body, decoding into a byte stream.
749
We read all bytes at once to ensure we've checked the trailer for
750
errors, and then feed the buffer back as read_body_bytes is called.
752
if self._body_buffer is not None:
753
return self._body_buffer.read(count)
754
_body_decoder = LengthPrefixedBodyDecoder()
756
while not _body_decoder.finished_reading:
757
bytes = self._request.read_bytes(_body_decoder.next_read_size())
759
# end of file encountered reading from server
760
raise errors.ConnectionReset(
761
"Connection lost while reading response body.")
762
_body_decoder.accept_bytes(bytes)
763
self._request.finished_reading()
764
self._body_buffer = StringIO(_body_decoder.read_pending_data())
765
# XXX: TODO check the trailer result.
766
if 'hpss' in debug.debug_flags:
767
mutter(' %d body bytes read',
768
len(self._body_buffer.getvalue()))
769
return self._body_buffer.read(count)
771
def _recv_tuple(self):
772
"""Receive a tuple from the medium request."""
773
return _decode_tuple(self._request.read_line())
775
def query_version(self):
776
"""Return protocol version number of the server."""
778
resp = self.read_response_tuple()
779
if resp == ('ok', '1'):
781
elif resp == ('ok', '2'):
784
raise errors.SmartProtocolError("bad response %r" % (resp,))
786
def _write_args(self, args):
787
self._write_protocol_version()
788
bytes = _encode_tuple(args)
789
self._request.accept_bytes(bytes)
791
def _write_protocol_version(self):
792
"""Write any prefixes this protocol requires.
794
Version one doesn't send protocol versions.
798
class SmartClientRequestProtocolTwo(SmartClientRequestProtocolOne):
799
"""Version two of the client side of the smart protocol.
801
This prefixes the request with the value of REQUEST_VERSION_TWO.
804
response_marker = RESPONSE_VERSION_TWO
805
request_marker = REQUEST_VERSION_TWO
807
def read_response_tuple(self, expect_body=False):
808
"""Read a response tuple from the wire.
810
This should only be called once.
812
version = self._request.read_line()
813
if version != self.response_marker:
814
self._request.finished_reading()
815
raise errors.UnexpectedProtocolVersionMarker(version)
816
response_status = self._request.read_line()
817
result = SmartClientRequestProtocolOne._read_response_tuple(self)
818
self._response_is_unknown_method(result)
819
if response_status == 'success\n':
820
self.response_status = True
822
self._request.finished_reading()
824
elif response_status == 'failed\n':
825
self.response_status = False
826
self._request.finished_reading()
827
raise errors.ErrorFromSmartServer(result)
829
raise errors.SmartProtocolError(
830
'bad protocol status %r' % response_status)
832
def _write_protocol_version(self):
833
"""Write any prefixes this protocol requires.
835
Version two sends the value of REQUEST_VERSION_TWO.
837
self._request.accept_bytes(self.request_marker)
839
def read_streamed_body(self):
840
"""Read bytes from the body, decoding into a byte stream.
842
# Read no more than 64k at a time so that we don't risk error 10055 (no
843
# buffer space available) on Windows.
844
_body_decoder = ChunkedBodyDecoder()
845
while not _body_decoder.finished_reading:
846
bytes = self._request.read_bytes(_body_decoder.next_read_size())
848
# end of file encountered reading from server
849
raise errors.ConnectionReset(
850
"Connection lost while reading streamed body.")
851
_body_decoder.accept_bytes(bytes)
852
for body_bytes in iter(_body_decoder.read_next_chunk, None):
853
if 'hpss' in debug.debug_flags and type(body_bytes) is str:
854
mutter(' %d byte chunk read',
857
self._request.finished_reading()
860
def build_server_protocol_three(backing_transport, write_func,
862
request_handler = request.SmartServerRequestHandler(
863
backing_transport, commands=request.request_handlers,
864
root_client_path=root_client_path)
865
responder = ProtocolThreeResponder(write_func)
866
message_handler = message.ConventionalRequestHandler(request_handler, responder)
867
return ProtocolThreeDecoder(message_handler)
870
class ProtocolThreeDecoder(_StatefulDecoder):
872
response_marker = RESPONSE_VERSION_THREE
873
request_marker = REQUEST_VERSION_THREE
875
def __init__(self, message_handler, expect_version_marker=False):
876
_StatefulDecoder.__init__(self)
877
self._has_dispatched = False
879
if expect_version_marker:
880
self.state_accept = self._state_accept_expecting_protocol_version
881
# We're expecting at least the protocol version marker + some
883
self._number_needed_bytes = len(MESSAGE_VERSION_THREE) + 4
885
self.state_accept = self._state_accept_expecting_headers
886
self._number_needed_bytes = 4
887
self.decoding_failed = False
888
self.request_handler = self.message_handler = message_handler
890
def accept_bytes(self, bytes):
891
self._number_needed_bytes = None
893
_StatefulDecoder.accept_bytes(self, bytes)
894
except KeyboardInterrupt:
896
except errors.SmartMessageHandlerError, exception:
897
# We do *not* set self.decoding_failed here. The message handler
898
# has raised an error, but the decoder is still able to parse bytes
899
# and determine when this message ends.
900
log_exception_quietly()
901
self.message_handler.protocol_error(exception.exc_value)
902
# The state machine is ready to continue decoding, but the
903
# exception has interrupted the loop that runs the state machine.
904
# So we call accept_bytes again to restart it.
905
self.accept_bytes('')
906
except Exception, exception:
907
# The decoder itself has raised an exception. We cannot continue
909
self.decoding_failed = True
910
if isinstance(exception, errors.UnexpectedProtocolVersionMarker):
911
# This happens during normal operation when the client tries a
912
# protocol version the server doesn't understand, so no need to
913
# log a traceback every time.
914
# Note that this can only happen when
915
# expect_version_marker=True, which is only the case on the
919
log_exception_quietly()
920
self.message_handler.protocol_error(exception)
922
def _extract_length_prefixed_bytes(self):
923
if self._in_buffer_len < 4:
924
# A length prefix by itself is 4 bytes, and we don't even have that
926
raise _NeedMoreBytes(4)
927
(length,) = struct.unpack('!L', self._get_in_bytes(4))
928
end_of_bytes = 4 + length
929
if self._in_buffer_len < end_of_bytes:
930
# We haven't yet read as many bytes as the length-prefix says there
932
raise _NeedMoreBytes(end_of_bytes)
933
# Extract the bytes from the buffer.
934
in_buf = self._get_in_buffer()
935
bytes = in_buf[4:end_of_bytes]
936
self._set_in_buffer(in_buf[end_of_bytes:])
939
def _extract_prefixed_bencoded_data(self):
940
prefixed_bytes = self._extract_length_prefixed_bytes()
942
decoded = bdecode_as_tuple(prefixed_bytes)
944
raise errors.SmartProtocolError(
945
'Bytes %r not bencoded' % (prefixed_bytes,))
948
def _extract_single_byte(self):
949
if self._in_buffer_len == 0:
950
# The buffer is empty
951
raise _NeedMoreBytes(1)
952
in_buf = self._get_in_buffer()
954
self._set_in_buffer(in_buf[1:])
957
def _state_accept_expecting_protocol_version(self):
958
needed_bytes = len(MESSAGE_VERSION_THREE) - self._in_buffer_len
959
in_buf = self._get_in_buffer()
961
# We don't have enough bytes to check if the protocol version
962
# marker is right. But we can check if it is already wrong by
963
# checking that the start of MESSAGE_VERSION_THREE matches what
965
# [In fact, if the remote end isn't bzr we might never receive
966
# len(MESSAGE_VERSION_THREE) bytes. So if the bytes we have so far
967
# are wrong then we should just raise immediately rather than
969
if not MESSAGE_VERSION_THREE.startswith(in_buf):
970
# We have enough bytes to know the protocol version is wrong
971
raise errors.UnexpectedProtocolVersionMarker(in_buf)
972
raise _NeedMoreBytes(len(MESSAGE_VERSION_THREE))
973
if not in_buf.startswith(MESSAGE_VERSION_THREE):
974
raise errors.UnexpectedProtocolVersionMarker(in_buf)
975
self._set_in_buffer(in_buf[len(MESSAGE_VERSION_THREE):])
976
self.state_accept = self._state_accept_expecting_headers
978
def _state_accept_expecting_headers(self):
979
decoded = self._extract_prefixed_bencoded_data()
980
if type(decoded) is not dict:
981
raise errors.SmartProtocolError(
982
'Header object %r is not a dict' % (decoded,))
983
self.state_accept = self._state_accept_expecting_message_part
985
self.message_handler.headers_received(decoded)
987
raise errors.SmartMessageHandlerError(sys.exc_info())
989
def _state_accept_expecting_message_part(self):
990
message_part_kind = self._extract_single_byte()
991
if message_part_kind == 'o':
992
self.state_accept = self._state_accept_expecting_one_byte
993
elif message_part_kind == 's':
994
self.state_accept = self._state_accept_expecting_structure
995
elif message_part_kind == 'b':
996
self.state_accept = self._state_accept_expecting_bytes
997
elif message_part_kind == 'e':
1000
raise errors.SmartProtocolError(
1001
'Bad message kind byte: %r' % (message_part_kind,))
1003
def _state_accept_expecting_one_byte(self):
1004
byte = self._extract_single_byte()
1005
self.state_accept = self._state_accept_expecting_message_part
1007
self.message_handler.byte_part_received(byte)
1009
raise errors.SmartMessageHandlerError(sys.exc_info())
1011
def _state_accept_expecting_bytes(self):
1012
# XXX: this should not buffer whole message part, but instead deliver
1013
# the bytes as they arrive.
1014
prefixed_bytes = self._extract_length_prefixed_bytes()
1015
self.state_accept = self._state_accept_expecting_message_part
1017
self.message_handler.bytes_part_received(prefixed_bytes)
1019
raise errors.SmartMessageHandlerError(sys.exc_info())
1021
def _state_accept_expecting_structure(self):
1022
structure = self._extract_prefixed_bencoded_data()
1023
self.state_accept = self._state_accept_expecting_message_part
1025
self.message_handler.structure_part_received(structure)
1027
raise errors.SmartMessageHandlerError(sys.exc_info())
1030
self.unused_data = self._get_in_buffer()
1031
self._set_in_buffer(None)
1032
self.state_accept = self._state_accept_reading_unused
1034
self.message_handler.end_received()
1036
raise errors.SmartMessageHandlerError(sys.exc_info())
1038
def _state_accept_reading_unused(self):
1039
self.unused_data += self._get_in_buffer()
1040
self._set_in_buffer(None)
1042
def next_read_size(self):
1043
if self.state_accept == self._state_accept_reading_unused:
1045
elif self.decoding_failed:
1046
# An exception occured while processing this message, probably from
1047
# self.message_handler. We're not sure that this state machine is
1048
# in a consistent state, so just signal that we're done (i.e. give
1052
if self._number_needed_bytes is not None:
1053
return self._number_needed_bytes - self._in_buffer_len
1055
raise AssertionError("don't know how many bytes are expected!")
1058
class _ProtocolThreeEncoder(object):
1060
response_marker = request_marker = MESSAGE_VERSION_THREE
1062
def __init__(self, write_func):
1064
self._real_write_func = write_func
1066
def _write_func(self, bytes):
1067
self._buf.append(bytes)
1068
if len(self._buf) > 100:
1073
self._real_write_func(''.join(self._buf))
1076
def _serialise_offsets(self, offsets):
1077
"""Serialise a readv offset list."""
1079
for start, length in offsets:
1080
txt.append('%d,%d' % (start, length))
1081
return '\n'.join(txt)
1083
def _write_protocol_version(self):
1084
self._write_func(MESSAGE_VERSION_THREE)
1086
def _write_prefixed_bencode(self, structure):
1087
bytes = bencode(structure)
1088
self._write_func(struct.pack('!L', len(bytes)))
1089
self._write_func(bytes)
1091
def _write_headers(self, headers):
1092
self._write_prefixed_bencode(headers)
1094
def _write_structure(self, args):
1095
self._write_func('s')
1098
if type(arg) is unicode:
1099
utf8_args.append(arg.encode('utf8'))
1101
utf8_args.append(arg)
1102
self._write_prefixed_bencode(utf8_args)
1104
def _write_end(self):
1105
self._write_func('e')
1108
def _write_prefixed_body(self, bytes):
1109
self._write_func('b')
1110
self._write_func(struct.pack('!L', len(bytes)))
1111
self._write_func(bytes)
1113
def _write_chunked_body_start(self):
1114
self._write_func('oC')
1116
def _write_error_status(self):
1117
self._write_func('oE')
1119
def _write_success_status(self):
1120
self._write_func('oS')
1123
class ProtocolThreeResponder(_ProtocolThreeEncoder):
1125
def __init__(self, write_func):
1126
_ProtocolThreeEncoder.__init__(self, write_func)
1127
self.response_sent = False
1128
self._headers = {'Software version': bzrlib.__version__}
1130
def send_error(self, exception):
1131
if self.response_sent:
1132
raise AssertionError(
1133
"send_error(%s) called, but response already sent."
1135
if isinstance(exception, errors.UnknownSmartMethod):
1136
failure = request.FailedSmartServerResponse(
1137
('UnknownMethod', exception.verb))
1138
self.send_response(failure)
1140
self.response_sent = True
1141
self._write_protocol_version()
1142
self._write_headers(self._headers)
1143
self._write_error_status()
1144
self._write_structure(('error', str(exception)))
1147
def send_response(self, response):
1148
if self.response_sent:
1149
raise AssertionError(
1150
"send_response(%r) called, but response already sent."
1152
self.response_sent = True
1153
self._write_protocol_version()
1154
self._write_headers(self._headers)
1155
if response.is_successful():
1156
self._write_success_status()
1158
self._write_error_status()
1159
self._write_structure(response.args)
1160
if response.body is not None:
1161
self._write_prefixed_body(response.body)
1162
elif response.body_stream is not None:
1163
for exc_info, chunk in _iter_with_errors(response.body_stream):
1164
if exc_info is not None:
1165
self._write_error_status()
1166
error_struct = request._translate_error(exc_info[1])
1167
self._write_structure(error_struct)
1170
if isinstance(chunk, request.FailedSmartServerResponse):
1171
self._write_error_status()
1172
self._write_structure(chunk.args)
1174
self._write_prefixed_body(chunk)
1178
def _iter_with_errors(iterable):
1179
"""Handle errors from iterable.next().
1183
for exc_info, value in _iter_with_errors(iterable):
1186
This is a safer alternative to::
1189
for value in iterable:
1194
Because the latter will catch errors from the for-loop body, not just
1197
If an error occurs, exc_info will be a exc_info tuple, and the generator
1198
will terminate. Otherwise exc_info will be None, and value will be the
1199
value from iterable.next(). Note that KeyboardInterrupt and SystemExit
1200
will not be itercepted.
1202
iterator = iter(iterable)
1205
yield None, iterator.next()
1206
except StopIteration:
1208
except (KeyboardInterrupt, SystemExit):
1211
yield sys.exc_info(), None
1215
class ProtocolThreeRequester(_ProtocolThreeEncoder, Requester):
1217
def __init__(self, medium_request):
1218
_ProtocolThreeEncoder.__init__(self, medium_request.accept_bytes)
1219
self._medium_request = medium_request
1222
def set_headers(self, headers):
1223
self._headers = headers.copy()
1225
def call(self, *args):
1226
if 'hpss' in debug.debug_flags:
1227
mutter('hpss call: %s', repr(args)[1:-1])
1228
base = getattr(self._medium_request._medium, 'base', None)
1229
if base is not None:
1230
mutter(' (to %s)', base)
1231
self._request_start_time = time.time()
1232
self._write_protocol_version()
1233
self._write_headers(self._headers)
1234
self._write_structure(args)
1236
self._medium_request.finished_writing()
1238
def call_with_body_bytes(self, args, body):
1239
"""Make a remote call of args with body bytes 'body'.
1241
After calling this, call read_response_tuple to find the result out.
1243
if 'hpss' in debug.debug_flags:
1244
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
1245
path = getattr(self._medium_request._medium, '_path', None)
1246
if path is not None:
1247
mutter(' (to %s)', path)
1248
mutter(' %d bytes', len(body))
1249
self._request_start_time = time.time()
1250
self._write_protocol_version()
1251
self._write_headers(self._headers)
1252
self._write_structure(args)
1253
self._write_prefixed_body(body)
1255
self._medium_request.finished_writing()
1257
def call_with_body_readv_array(self, args, body):
1258
"""Make a remote call with a readv array.
1260
The body is encoded with one line per readv offset pair. The numbers in
1261
each pair are separated by a comma, and no trailing \n is emitted.
1263
if 'hpss' in debug.debug_flags:
1264
mutter('hpss call w/readv: %s', repr(args)[1:-1])
1265
path = getattr(self._medium_request._medium, '_path', None)
1266
if path is not None:
1267
mutter(' (to %s)', path)
1268
self._request_start_time = time.time()
1269
self._write_protocol_version()
1270
self._write_headers(self._headers)
1271
self._write_structure(args)
1272
readv_bytes = self._serialise_offsets(body)
1273
if 'hpss' in debug.debug_flags:
1274
mutter(' %d bytes in readv request', len(readv_bytes))
1275
self._write_prefixed_body(readv_bytes)
1277
self._medium_request.finished_writing()
1279
def call_with_body_stream(self, args, stream):
1280
if 'hpss' in debug.debug_flags:
1281
mutter('hpss call w/body stream: %r', args)
1282
path = getattr(self._medium_request._medium, '_path', None)
1283
if path is not None:
1284
mutter(' (to %s)', path)
1285
self._request_start_time = time.time()
1286
self._write_protocol_version()
1287
self._write_headers(self._headers)
1288
self._write_structure(args)
1289
# TODO: notice if the server has sent an early error reply before we
1290
# have finished sending the stream. We would notice at the end
1291
# anyway, but if the medium can deliver it early then it's good
1292
# to short-circuit the whole request...
1293
for exc_info, part in _iter_with_errors(stream):
1294
if exc_info is not None:
1295
# Iterating the stream failed. Cleanly abort the request.
1296
self._write_error_status()
1297
# Currently the client unconditionally sends ('error',) as the
1299
self._write_structure(('error',))
1301
self._medium_request.finished_writing()
1302
raise exc_info[0], exc_info[1], exc_info[2]
1304
self._write_prefixed_body(part)
1307
self._medium_request.finished_writing()
added
removed
bzrlib/smart/protocol.py
