/usr/lib/python2.7/dist-packages/bzrlib/smart/protocol.py is in python-bzrlib 2.7.0-2ubuntu3.1.
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#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Wire-level encoding and decoding of requests and responses for the smart
client and server.
"""
from __future__ import absolute_import
import collections
from cStringIO import StringIO
import struct
import sys
import thread
import time
import bzrlib
from bzrlib import (
debug,
errors,
osutils,
)
from bzrlib.smart import message, request
from bzrlib.trace import log_exception_quietly, mutter
from bzrlib.bencode import bdecode_as_tuple, bencode
# Protocol version strings. These are sent as prefixes of bzr requests and
# responses to identify the protocol version being used. (There are no version
# one strings because that version doesn't send any).
REQUEST_VERSION_TWO = 'bzr request 2\n'
RESPONSE_VERSION_TWO = 'bzr response 2\n'
MESSAGE_VERSION_THREE = 'bzr message 3 (bzr 1.6)\n'
RESPONSE_VERSION_THREE = REQUEST_VERSION_THREE = MESSAGE_VERSION_THREE
def _recv_tuple(from_file):
req_line = from_file.readline()
return _decode_tuple(req_line)
def _decode_tuple(req_line):
if req_line is None or req_line == '':
return None
if req_line[-1] != '\n':
raise errors.SmartProtocolError("request %r not terminated" % req_line)
return tuple(req_line[:-1].split('\x01'))
def _encode_tuple(args):
"""Encode the tuple args to a bytestream."""
joined = '\x01'.join(args) + '\n'
if type(joined) is unicode:
# XXX: We should fix things so this never happens! -AJB, 20100304
mutter('response args contain unicode, should be only bytes: %r',
joined)
joined = joined.encode('ascii')
return joined
class Requester(object):
"""Abstract base class for an object that can issue requests on a smart
medium.
"""
def call(self, *args):
"""Make a remote call.
:param args: the arguments of this call.
"""
raise NotImplementedError(self.call)
def call_with_body_bytes(self, args, body):
"""Make a remote call with a body.
:param args: the arguments of this call.
:type body: str
:param body: the body to send with the request.
"""
raise NotImplementedError(self.call_with_body_bytes)
def call_with_body_readv_array(self, args, body):
"""Make a remote call with a readv array.
:param args: the arguments of this call.
:type body: iterable of (start, length) tuples.
:param body: the readv ranges to send with this request.
"""
raise NotImplementedError(self.call_with_body_readv_array)
def set_headers(self, headers):
raise NotImplementedError(self.set_headers)
class SmartProtocolBase(object):
"""Methods common to client and server"""
# TODO: this only actually accomodates a single block; possibly should
# support multiple chunks?
def _encode_bulk_data(self, body):
"""Encode body as a bulk data chunk."""
return ''.join(('%d\n' % len(body), body, 'done\n'))
def _serialise_offsets(self, offsets):
"""Serialise a readv offset list."""
txt = []
for start, length in offsets:
txt.append('%d,%d' % (start, length))
return '\n'.join(txt)
class SmartServerRequestProtocolOne(SmartProtocolBase):
"""Server-side encoding and decoding logic for smart version 1."""
def __init__(self, backing_transport, write_func, root_client_path='/',
jail_root=None):
self._backing_transport = backing_transport
self._root_client_path = root_client_path
self._jail_root = jail_root
self.unused_data = ''
self._finished = False
self.in_buffer = ''
self._has_dispatched = False
self.request = None
self._body_decoder = None
self._write_func = write_func
def accept_bytes(self, bytes):
"""Take bytes, and advance the internal state machine appropriately.
:param bytes: must be a byte string
"""
if not isinstance(bytes, str):
raise ValueError(bytes)
self.in_buffer += bytes
if not self._has_dispatched:
if '\n' not in self.in_buffer:
# no command line yet
return
self._has_dispatched = True
try:
first_line, self.in_buffer = self.in_buffer.split('\n', 1)
first_line += '\n'
req_args = _decode_tuple(first_line)
self.request = request.SmartServerRequestHandler(
self._backing_transport, commands=request.request_handlers,
root_client_path=self._root_client_path,
jail_root=self._jail_root)
self.request.args_received(req_args)
if self.request.finished_reading:
# trivial request
self.unused_data = self.in_buffer
self.in_buffer = ''
self._send_response(self.request.response)
except KeyboardInterrupt:
raise
except errors.UnknownSmartMethod, err:
protocol_error = errors.SmartProtocolError(
"bad request %r" % (err.verb,))
failure = request.FailedSmartServerResponse(
('error', str(protocol_error)))
self._send_response(failure)
return
except Exception, exception:
# everything else: pass to client, flush, and quit
log_exception_quietly()
self._send_response(request.FailedSmartServerResponse(
('error', str(exception))))
return
if self._has_dispatched:
if self._finished:
# nothing to do.XXX: this routine should be a single state
# machine too.
self.unused_data += self.in_buffer
self.in_buffer = ''
return
if self._body_decoder is None:
self._body_decoder = LengthPrefixedBodyDecoder()
self._body_decoder.accept_bytes(self.in_buffer)
self.in_buffer = self._body_decoder.unused_data
body_data = self._body_decoder.read_pending_data()
self.request.accept_body(body_data)
if self._body_decoder.finished_reading:
self.request.end_of_body()
if not self.request.finished_reading:
raise AssertionError("no more body, request not finished")
if self.request.response is not None:
self._send_response(self.request.response)
self.unused_data = self.in_buffer
self.in_buffer = ''
else:
if self.request.finished_reading:
raise AssertionError(
"no response and we have finished reading.")
def _send_response(self, response):
"""Send a smart server response down the output stream."""
if self._finished:
raise AssertionError('response already sent')
args = response.args
body = response.body
self._finished = True
self._write_protocol_version()
self._write_success_or_failure_prefix(response)
self._write_func(_encode_tuple(args))
if body is not None:
if not isinstance(body, str):
raise ValueError(body)
bytes = self._encode_bulk_data(body)
self._write_func(bytes)
def _write_protocol_version(self):
"""Write any prefixes this protocol requires.
Version one doesn't send protocol versions.
"""
def _write_success_or_failure_prefix(self, response):
"""Write the protocol specific success/failure prefix.
For SmartServerRequestProtocolOne this is omitted but we
call is_successful to ensure that the response is valid.
"""
response.is_successful()
def next_read_size(self):
if self._finished:
return 0
if self._body_decoder is None:
return 1
else:
return self._body_decoder.next_read_size()
class SmartServerRequestProtocolTwo(SmartServerRequestProtocolOne):
r"""Version two of the server side of the smart protocol.
This prefixes responses with the value of RESPONSE_VERSION_TWO.
"""
response_marker = RESPONSE_VERSION_TWO
request_marker = REQUEST_VERSION_TWO
def _write_success_or_failure_prefix(self, response):
"""Write the protocol specific success/failure prefix."""
if response.is_successful():
self._write_func('success\n')
else:
self._write_func('failed\n')
def _write_protocol_version(self):
r"""Write any prefixes this protocol requires.
Version two sends the value of RESPONSE_VERSION_TWO.
"""
self._write_func(self.response_marker)
def _send_response(self, response):
"""Send a smart server response down the output stream."""
if (self._finished):
raise AssertionError('response already sent')
self._finished = True
self._write_protocol_version()
self._write_success_or_failure_prefix(response)
self._write_func(_encode_tuple(response.args))
if response.body is not None:
if not isinstance(response.body, str):
raise AssertionError('body must be a str')
if not (response.body_stream is None):
raise AssertionError(
'body_stream and body cannot both be set')
bytes = self._encode_bulk_data(response.body)
self._write_func(bytes)
elif response.body_stream is not None:
_send_stream(response.body_stream, self._write_func)
def _send_stream(stream, write_func):
write_func('chunked\n')
_send_chunks(stream, write_func)
write_func('END\n')
def _send_chunks(stream, write_func):
for chunk in stream:
if isinstance(chunk, str):
bytes = "%x\n%s" % (len(chunk), chunk)
write_func(bytes)
elif isinstance(chunk, request.FailedSmartServerResponse):
write_func('ERR\n')
_send_chunks(chunk.args, write_func)
return
else:
raise errors.BzrError(
'Chunks must be str or FailedSmartServerResponse, got %r'
% chunk)
class _NeedMoreBytes(Exception):
"""Raise this inside a _StatefulDecoder to stop decoding until more bytes
have been received.
"""
def __init__(self, count=None):
"""Constructor.
:param count: the total number of bytes needed by the current state.
May be None if the number of bytes needed is unknown.
"""
self.count = count
class _StatefulDecoder(object):
"""Base class for writing state machines to decode byte streams.
Subclasses should provide a self.state_accept attribute that accepts bytes
and, if appropriate, updates self.state_accept to a different function.
accept_bytes will call state_accept as often as necessary to make sure the
state machine has progressed as far as possible before it returns.
See ProtocolThreeDecoder for an example subclass.
"""
def __init__(self):
self.finished_reading = False
self._in_buffer_list = []
self._in_buffer_len = 0
self.unused_data = ''
self.bytes_left = None
self._number_needed_bytes = None
def _get_in_buffer(self):
if len(self._in_buffer_list) == 1:
return self._in_buffer_list[0]
in_buffer = ''.join(self._in_buffer_list)
if len(in_buffer) != self._in_buffer_len:
raise AssertionError(
"Length of buffer did not match expected value: %s != %s"
% self._in_buffer_len, len(in_buffer))
self._in_buffer_list = [in_buffer]
return in_buffer
def _get_in_bytes(self, count):
"""Grab X bytes from the input_buffer.
Callers should have already checked that self._in_buffer_len is >
count. Note, this does not consume the bytes from the buffer. The
caller will still need to call _get_in_buffer() and then
_set_in_buffer() if they actually need to consume the bytes.
"""
# check if we can yield the bytes from just the first entry in our list
if len(self._in_buffer_list) == 0:
raise AssertionError('Callers must be sure we have buffered bytes'
' before calling _get_in_bytes')
if len(self._in_buffer_list[0]) > count:
return self._in_buffer_list[0][:count]
# We can't yield it from the first buffer, so collapse all buffers, and
# yield it from that
in_buf = self._get_in_buffer()
return in_buf[:count]
def _set_in_buffer(self, new_buf):
if new_buf is not None:
self._in_buffer_list = [new_buf]
self._in_buffer_len = len(new_buf)
else:
self._in_buffer_list = []
self._in_buffer_len = 0
def accept_bytes(self, bytes):
"""Decode as much of bytes as possible.
If 'bytes' contains too much data it will be appended to
self.unused_data.
finished_reading will be set when no more data is required. Further
data will be appended to self.unused_data.
"""
# accept_bytes is allowed to change the state
self._number_needed_bytes = None
# lsprof puts a very large amount of time on this specific call for
# large readv arrays
self._in_buffer_list.append(bytes)
self._in_buffer_len += len(bytes)
try:
# Run the function for the current state.
current_state = self.state_accept
self.state_accept()
while current_state != self.state_accept:
# The current state has changed. Run the function for the new
# current state, so that it can:
# - decode any unconsumed bytes left in a buffer, and
# - signal how many more bytes are expected (via raising
# _NeedMoreBytes).
current_state = self.state_accept
self.state_accept()
except _NeedMoreBytes, e:
self._number_needed_bytes = e.count
class ChunkedBodyDecoder(_StatefulDecoder):
"""Decoder for chunked body data.
This is very similar the HTTP's chunked encoding. See the description of
streamed body data in `doc/developers/network-protocol.txt` for details.
"""
def __init__(self):
_StatefulDecoder.__init__(self)
self.state_accept = self._state_accept_expecting_header
self.chunk_in_progress = None
self.chunks = collections.deque()
self.error = False
self.error_in_progress = None
def next_read_size(self):
# Note: the shortest possible chunk is 2 bytes: '0\n', and the
# end-of-body marker is 4 bytes: 'END\n'.
if self.state_accept == self._state_accept_reading_chunk:
# We're expecting more chunk content. So we're expecting at least
# the rest of this chunk plus an END chunk.
return self.bytes_left + 4
elif self.state_accept == self._state_accept_expecting_length:
if self._in_buffer_len == 0:
# We're expecting a chunk length. There's at least two bytes
# left: a digit plus '\n'.
return 2
else:
# We're in the middle of reading a chunk length. So there's at
# least one byte left, the '\n' that terminates the length.
return 1
elif self.state_accept == self._state_accept_reading_unused:
return 1
elif self.state_accept == self._state_accept_expecting_header:
return max(0, len('chunked\n') - self._in_buffer_len)
else:
raise AssertionError("Impossible state: %r" % (self.state_accept,))
def read_next_chunk(self):
try:
return self.chunks.popleft()
except IndexError:
return None
def _extract_line(self):
in_buf = self._get_in_buffer()
pos = in_buf.find('\n')
if pos == -1:
# We haven't read a complete line yet, so request more bytes before
# we continue.
raise _NeedMoreBytes(1)
line = in_buf[:pos]
# Trim the prefix (including '\n' delimiter) from the _in_buffer.
self._set_in_buffer(in_buf[pos+1:])
return line
def _finished(self):
self.unused_data = self._get_in_buffer()
self._in_buffer_list = []
self._in_buffer_len = 0
self.state_accept = self._state_accept_reading_unused
if self.error:
error_args = tuple(self.error_in_progress)
self.chunks.append(request.FailedSmartServerResponse(error_args))
self.error_in_progress = None
self.finished_reading = True
def _state_accept_expecting_header(self):
prefix = self._extract_line()
if prefix == 'chunked':
self.state_accept = self._state_accept_expecting_length
else:
raise errors.SmartProtocolError(
'Bad chunked body header: "%s"' % (prefix,))
def _state_accept_expecting_length(self):
prefix = self._extract_line()
if prefix == 'ERR':
self.error = True
self.error_in_progress = []
self._state_accept_expecting_length()
return
elif prefix == 'END':
# We've read the end-of-body marker.
# Any further bytes are unused data, including the bytes left in
# the _in_buffer.
self._finished()
return
else:
self.bytes_left = int(prefix, 16)
self.chunk_in_progress = ''
self.state_accept = self._state_accept_reading_chunk
def _state_accept_reading_chunk(self):
in_buf = self._get_in_buffer()
in_buffer_len = len(in_buf)
self.chunk_in_progress += in_buf[:self.bytes_left]
self._set_in_buffer(in_buf[self.bytes_left:])
self.bytes_left -= in_buffer_len
if self.bytes_left <= 0:
# Finished with chunk
self.bytes_left = None
if self.error:
self.error_in_progress.append(self.chunk_in_progress)
else:
self.chunks.append(self.chunk_in_progress)
self.chunk_in_progress = None
self.state_accept = self._state_accept_expecting_length
def _state_accept_reading_unused(self):
self.unused_data += self._get_in_buffer()
self._in_buffer_list = []
class LengthPrefixedBodyDecoder(_StatefulDecoder):
"""Decodes the length-prefixed bulk data."""
def __init__(self):
_StatefulDecoder.__init__(self)
self.state_accept = self._state_accept_expecting_length
self.state_read = self._state_read_no_data
self._body = ''
self._trailer_buffer = ''
def next_read_size(self):
if self.bytes_left is not None:
# Ideally we want to read all the remainder of the body and the
# trailer in one go.
return self.bytes_left + 5
elif self.state_accept == self._state_accept_reading_trailer:
# Just the trailer left
return 5 - len(self._trailer_buffer)
elif self.state_accept == self._state_accept_expecting_length:
# There's still at least 6 bytes left ('\n' to end the length, plus
# 'done\n').
return 6
else:
# Reading excess data. Either way, 1 byte at a time is fine.
return 1
def read_pending_data(self):
"""Return any pending data that has been decoded."""
return self.state_read()
def _state_accept_expecting_length(self):
in_buf = self._get_in_buffer()
pos = in_buf.find('\n')
if pos == -1:
return
self.bytes_left = int(in_buf[:pos])
self._set_in_buffer(in_buf[pos+1:])
self.state_accept = self._state_accept_reading_body
self.state_read = self._state_read_body_buffer
def _state_accept_reading_body(self):
in_buf = self._get_in_buffer()
self._body += in_buf
self.bytes_left -= len(in_buf)
self._set_in_buffer(None)
if self.bytes_left <= 0:
# Finished with body
if self.bytes_left != 0:
self._trailer_buffer = self._body[self.bytes_left:]
self._body = self._body[:self.bytes_left]
self.bytes_left = None
self.state_accept = self._state_accept_reading_trailer
def _state_accept_reading_trailer(self):
self._trailer_buffer += self._get_in_buffer()
self._set_in_buffer(None)
# TODO: what if the trailer does not match "done\n"? Should this raise
# a ProtocolViolation exception?
if self._trailer_buffer.startswith('done\n'):
self.unused_data = self._trailer_buffer[len('done\n'):]
self.state_accept = self._state_accept_reading_unused
self.finished_reading = True
def _state_accept_reading_unused(self):
self.unused_data += self._get_in_buffer()
self._set_in_buffer(None)
def _state_read_no_data(self):
return ''
def _state_read_body_buffer(self):
result = self._body
self._body = ''
return result
class SmartClientRequestProtocolOne(SmartProtocolBase, Requester,
message.ResponseHandler):
"""The client-side protocol for smart version 1."""
def __init__(self, request):
"""Construct a SmartClientRequestProtocolOne.
:param request: A SmartClientMediumRequest to serialise onto and
deserialise from.
"""
self._request = request
self._body_buffer = None
self._request_start_time = None
self._last_verb = None
self._headers = None
def set_headers(self, headers):
self._headers = dict(headers)
def call(self, *args):
if 'hpss' in debug.debug_flags:
mutter('hpss call: %s', repr(args)[1:-1])
if getattr(self._request._medium, 'base', None) is not None:
mutter(' (to %s)', self._request._medium.base)
self._request_start_time = osutils.timer_func()
self._write_args(args)
self._request.finished_writing()
self._last_verb = args[0]
def call_with_body_bytes(self, args, body):
"""Make a remote call of args with body bytes 'body'.
After calling this, call read_response_tuple to find the result out.
"""
if 'hpss' in debug.debug_flags:
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
if getattr(self._request._medium, '_path', None) is not None:
mutter(' (to %s)', self._request._medium._path)
mutter(' %d bytes', len(body))
self._request_start_time = osutils.timer_func()
if 'hpssdetail' in debug.debug_flags:
mutter('hpss body content: %s', body)
self._write_args(args)
bytes = self._encode_bulk_data(body)
self._request.accept_bytes(bytes)
self._request.finished_writing()
self._last_verb = args[0]
def call_with_body_readv_array(self, args, body):
"""Make a remote call with a readv array.
The body is encoded with one line per readv offset pair. The numbers in
each pair are separated by a comma, and no trailing \\n is emitted.
"""
if 'hpss' in debug.debug_flags:
mutter('hpss call w/readv: %s', repr(args)[1:-1])
if getattr(self._request._medium, '_path', None) is not None:
mutter(' (to %s)', self._request._medium._path)
self._request_start_time = osutils.timer_func()
self._write_args(args)
readv_bytes = self._serialise_offsets(body)
bytes = self._encode_bulk_data(readv_bytes)
self._request.accept_bytes(bytes)
self._request.finished_writing()
if 'hpss' in debug.debug_flags:
mutter(' %d bytes in readv request', len(readv_bytes))
self._last_verb = args[0]
def call_with_body_stream(self, args, stream):
# Protocols v1 and v2 don't support body streams. So it's safe to
# assume that a v1/v2 server doesn't support whatever method we're
# trying to call with a body stream.
self._request.finished_writing()
self._request.finished_reading()
raise errors.UnknownSmartMethod(args[0])
def cancel_read_body(self):
"""After expecting a body, a response code may indicate one otherwise.
This method lets the domain client inform the protocol that no body
will be transmitted. This is a terminal method: after calling it the
protocol is not able to be used further.
"""
self._request.finished_reading()
def _read_response_tuple(self):
result = self._recv_tuple()
if 'hpss' in debug.debug_flags:
if self._request_start_time is not None:
mutter(' result: %6.3fs %s',
osutils.timer_func() - self._request_start_time,
repr(result)[1:-1])
self._request_start_time = None
else:
mutter(' result: %s', repr(result)[1:-1])
return result
def read_response_tuple(self, expect_body=False):
"""Read a response tuple from the wire.
This should only be called once.
"""
result = self._read_response_tuple()
self._response_is_unknown_method(result)
self._raise_args_if_error(result)
if not expect_body:
self._request.finished_reading()
return result
def _raise_args_if_error(self, result_tuple):
# Later protocol versions have an explicit flag in the protocol to say
# if an error response is "failed" or not. In version 1 we don't have
# that luxury. So here is a complete list of errors that can be
# returned in response to existing version 1 smart requests. Responses
# starting with these codes are always "failed" responses.
v1_error_codes = [
'norepository',
'NoSuchFile',
'FileExists',
'DirectoryNotEmpty',
'ShortReadvError',
'UnicodeEncodeError',
'UnicodeDecodeError',
'ReadOnlyError',
'nobranch',
'NoSuchRevision',
'nosuchrevision',
'LockContention',
'UnlockableTransport',
'LockFailed',
'TokenMismatch',
'ReadError',
'PermissionDenied',
]
if result_tuple[0] in v1_error_codes:
self._request.finished_reading()
raise errors.ErrorFromSmartServer(result_tuple)
def _response_is_unknown_method(self, result_tuple):
"""Raise UnexpectedSmartServerResponse if the response is an 'unknonwn
method' response to the request.
:param response: The response from a smart client call_expecting_body
call.
:param verb: The verb used in that call.
:raises: UnexpectedSmartServerResponse
"""
if (result_tuple == ('error', "Generic bzr smart protocol error: "
"bad request '%s'" % self._last_verb) or
result_tuple == ('error', "Generic bzr smart protocol error: "
"bad request u'%s'" % self._last_verb)):
# The response will have no body, so we've finished reading.
self._request.finished_reading()
raise errors.UnknownSmartMethod(self._last_verb)
def read_body_bytes(self, count=-1):
"""Read bytes from the body, decoding into a byte stream.
We read all bytes at once to ensure we've checked the trailer for
errors, and then feed the buffer back as read_body_bytes is called.
"""
if self._body_buffer is not None:
return self._body_buffer.read(count)
_body_decoder = LengthPrefixedBodyDecoder()
while not _body_decoder.finished_reading:
bytes = self._request.read_bytes(_body_decoder.next_read_size())
if bytes == '':
# end of file encountered reading from server
raise errors.ConnectionReset(
"Connection lost while reading response body.")
_body_decoder.accept_bytes(bytes)
self._request.finished_reading()
self._body_buffer = StringIO(_body_decoder.read_pending_data())
# XXX: TODO check the trailer result.
if 'hpss' in debug.debug_flags:
mutter(' %d body bytes read',
len(self._body_buffer.getvalue()))
return self._body_buffer.read(count)
def _recv_tuple(self):
"""Receive a tuple from the medium request."""
return _decode_tuple(self._request.read_line())
def query_version(self):
"""Return protocol version number of the server."""
self.call('hello')
resp = self.read_response_tuple()
if resp == ('ok', '1'):
return 1
elif resp == ('ok', '2'):
return 2
else:
raise errors.SmartProtocolError("bad response %r" % (resp,))
def _write_args(self, args):
self._write_protocol_version()
bytes = _encode_tuple(args)
self._request.accept_bytes(bytes)
def _write_protocol_version(self):
"""Write any prefixes this protocol requires.
Version one doesn't send protocol versions.
"""
class SmartClientRequestProtocolTwo(SmartClientRequestProtocolOne):
"""Version two of the client side of the smart protocol.
This prefixes the request with the value of REQUEST_VERSION_TWO.
"""
response_marker = RESPONSE_VERSION_TWO
request_marker = REQUEST_VERSION_TWO
def read_response_tuple(self, expect_body=False):
"""Read a response tuple from the wire.
This should only be called once.
"""
version = self._request.read_line()
if version != self.response_marker:
self._request.finished_reading()
raise errors.UnexpectedProtocolVersionMarker(version)
response_status = self._request.read_line()
result = SmartClientRequestProtocolOne._read_response_tuple(self)
self._response_is_unknown_method(result)
if response_status == 'success\n':
self.response_status = True
if not expect_body:
self._request.finished_reading()
return result
elif response_status == 'failed\n':
self.response_status = False
self._request.finished_reading()
raise errors.ErrorFromSmartServer(result)
else:
raise errors.SmartProtocolError(
'bad protocol status %r' % response_status)
def _write_protocol_version(self):
"""Write any prefixes this protocol requires.
Version two sends the value of REQUEST_VERSION_TWO.
"""
self._request.accept_bytes(self.request_marker)
def read_streamed_body(self):
"""Read bytes from the body, decoding into a byte stream.
"""
# Read no more than 64k at a time so that we don't risk error 10055 (no
# buffer space available) on Windows.
_body_decoder = ChunkedBodyDecoder()
while not _body_decoder.finished_reading:
bytes = self._request.read_bytes(_body_decoder.next_read_size())
if bytes == '':
# end of file encountered reading from server
raise errors.ConnectionReset(
"Connection lost while reading streamed body.")
_body_decoder.accept_bytes(bytes)
for body_bytes in iter(_body_decoder.read_next_chunk, None):
if 'hpss' in debug.debug_flags and type(body_bytes) is str:
mutter(' %d byte chunk read',
len(body_bytes))
yield body_bytes
self._request.finished_reading()
def build_server_protocol_three(backing_transport, write_func,
root_client_path, jail_root=None):
request_handler = request.SmartServerRequestHandler(
backing_transport, commands=request.request_handlers,
root_client_path=root_client_path, jail_root=jail_root)
responder = ProtocolThreeResponder(write_func)
message_handler = message.ConventionalRequestHandler(request_handler, responder)
return ProtocolThreeDecoder(message_handler)
class ProtocolThreeDecoder(_StatefulDecoder):
response_marker = RESPONSE_VERSION_THREE
request_marker = REQUEST_VERSION_THREE
def __init__(self, message_handler, expect_version_marker=False):
_StatefulDecoder.__init__(self)
self._has_dispatched = False
# Initial state
if expect_version_marker:
self.state_accept = self._state_accept_expecting_protocol_version
# We're expecting at least the protocol version marker + some
# headers.
self._number_needed_bytes = len(MESSAGE_VERSION_THREE) + 4
else:
self.state_accept = self._state_accept_expecting_headers
self._number_needed_bytes = 4
self.decoding_failed = False
self.request_handler = self.message_handler = message_handler
def accept_bytes(self, bytes):
self._number_needed_bytes = None
try:
_StatefulDecoder.accept_bytes(self, bytes)
except KeyboardInterrupt:
raise
except errors.SmartMessageHandlerError, exception:
# We do *not* set self.decoding_failed here. The message handler
# has raised an error, but the decoder is still able to parse bytes
# and determine when this message ends.
if not isinstance(exception.exc_value, errors.UnknownSmartMethod):
log_exception_quietly()
self.message_handler.protocol_error(exception.exc_value)
# The state machine is ready to continue decoding, but the
# exception has interrupted the loop that runs the state machine.
# So we call accept_bytes again to restart it.
self.accept_bytes('')
except Exception, exception:
# The decoder itself has raised an exception. We cannot continue
# decoding.
self.decoding_failed = True
if isinstance(exception, errors.UnexpectedProtocolVersionMarker):
# This happens during normal operation when the client tries a
# protocol version the server doesn't understand, so no need to
# log a traceback every time.
# Note that this can only happen when
# expect_version_marker=True, which is only the case on the
# client side.
pass
else:
log_exception_quietly()
self.message_handler.protocol_error(exception)
def _extract_length_prefixed_bytes(self):
if self._in_buffer_len < 4:
# A length prefix by itself is 4 bytes, and we don't even have that
# many yet.
raise _NeedMoreBytes(4)
(length,) = struct.unpack('!L', self._get_in_bytes(4))
end_of_bytes = 4 + length
if self._in_buffer_len < end_of_bytes:
# We haven't yet read as many bytes as the length-prefix says there
# are.
raise _NeedMoreBytes(end_of_bytes)
# Extract the bytes from the buffer.
in_buf = self._get_in_buffer()
bytes = in_buf[4:end_of_bytes]
self._set_in_buffer(in_buf[end_of_bytes:])
return bytes
def _extract_prefixed_bencoded_data(self):
prefixed_bytes = self._extract_length_prefixed_bytes()
try:
decoded = bdecode_as_tuple(prefixed_bytes)
except ValueError:
raise errors.SmartProtocolError(
'Bytes %r not bencoded' % (prefixed_bytes,))
return decoded
def _extract_single_byte(self):
if self._in_buffer_len == 0:
# The buffer is empty
raise _NeedMoreBytes(1)
in_buf = self._get_in_buffer()
one_byte = in_buf[0]
self._set_in_buffer(in_buf[1:])
return one_byte
def _state_accept_expecting_protocol_version(self):
needed_bytes = len(MESSAGE_VERSION_THREE) - self._in_buffer_len
in_buf = self._get_in_buffer()
if needed_bytes > 0:
# We don't have enough bytes to check if the protocol version
# marker is right. But we can check if it is already wrong by
# checking that the start of MESSAGE_VERSION_THREE matches what
# we've read so far.
# [In fact, if the remote end isn't bzr we might never receive
# len(MESSAGE_VERSION_THREE) bytes. So if the bytes we have so far
# are wrong then we should just raise immediately rather than
# stall.]
if not MESSAGE_VERSION_THREE.startswith(in_buf):
# We have enough bytes to know the protocol version is wrong
raise errors.UnexpectedProtocolVersionMarker(in_buf)
raise _NeedMoreBytes(len(MESSAGE_VERSION_THREE))
if not in_buf.startswith(MESSAGE_VERSION_THREE):
raise errors.UnexpectedProtocolVersionMarker(in_buf)
self._set_in_buffer(in_buf[len(MESSAGE_VERSION_THREE):])
self.state_accept = self._state_accept_expecting_headers
def _state_accept_expecting_headers(self):
decoded = self._extract_prefixed_bencoded_data()
if type(decoded) is not dict:
raise errors.SmartProtocolError(
'Header object %r is not a dict' % (decoded,))
self.state_accept = self._state_accept_expecting_message_part
try:
self.message_handler.headers_received(decoded)
except:
raise errors.SmartMessageHandlerError(sys.exc_info())
def _state_accept_expecting_message_part(self):
message_part_kind = self._extract_single_byte()
if message_part_kind == 'o':
self.state_accept = self._state_accept_expecting_one_byte
elif message_part_kind == 's':
self.state_accept = self._state_accept_expecting_structure
elif message_part_kind == 'b':
self.state_accept = self._state_accept_expecting_bytes
elif message_part_kind == 'e':
self.done()
else:
raise errors.SmartProtocolError(
'Bad message kind byte: %r' % (message_part_kind,))
def _state_accept_expecting_one_byte(self):
byte = self._extract_single_byte()
self.state_accept = self._state_accept_expecting_message_part
try:
self.message_handler.byte_part_received(byte)
except:
raise errors.SmartMessageHandlerError(sys.exc_info())
def _state_accept_expecting_bytes(self):
# XXX: this should not buffer whole message part, but instead deliver
# the bytes as they arrive.
prefixed_bytes = self._extract_length_prefixed_bytes()
self.state_accept = self._state_accept_expecting_message_part
try:
self.message_handler.bytes_part_received(prefixed_bytes)
except:
raise errors.SmartMessageHandlerError(sys.exc_info())
def _state_accept_expecting_structure(self):
structure = self._extract_prefixed_bencoded_data()
self.state_accept = self._state_accept_expecting_message_part
try:
self.message_handler.structure_part_received(structure)
except:
raise errors.SmartMessageHandlerError(sys.exc_info())
def done(self):
self.unused_data = self._get_in_buffer()
self._set_in_buffer(None)
self.state_accept = self._state_accept_reading_unused
try:
self.message_handler.end_received()
except:
raise errors.SmartMessageHandlerError(sys.exc_info())
def _state_accept_reading_unused(self):
self.unused_data += self._get_in_buffer()
self._set_in_buffer(None)
def next_read_size(self):
if self.state_accept == self._state_accept_reading_unused:
return 0
elif self.decoding_failed:
# An exception occured while processing this message, probably from
# self.message_handler. We're not sure that this state machine is
# in a consistent state, so just signal that we're done (i.e. give
# up).
return 0
else:
if self._number_needed_bytes is not None:
return self._number_needed_bytes - self._in_buffer_len
else:
raise AssertionError("don't know how many bytes are expected!")
class _ProtocolThreeEncoder(object):
response_marker = request_marker = MESSAGE_VERSION_THREE
BUFFER_SIZE = 1024*1024 # 1 MiB buffer before flushing
def __init__(self, write_func):
self._buf = []
self._buf_len = 0
self._real_write_func = write_func
def _write_func(self, bytes):
# TODO: Another possibility would be to turn this into an async model.
# Where we let another thread know that we have some bytes if
# they want it, but we don't actually block for it
# Note that osutils.send_all always sends 64kB chunks anyway, so
# we might just push out smaller bits at a time?
self._buf.append(bytes)
self._buf_len += len(bytes)
if self._buf_len > self.BUFFER_SIZE:
self.flush()
def flush(self):
if self._buf:
self._real_write_func(''.join(self._buf))
del self._buf[:]
self._buf_len = 0
def _serialise_offsets(self, offsets):
"""Serialise a readv offset list."""
txt = []
for start, length in offsets:
txt.append('%d,%d' % (start, length))
return '\n'.join(txt)
def _write_protocol_version(self):
self._write_func(MESSAGE_VERSION_THREE)
def _write_prefixed_bencode(self, structure):
bytes = bencode(structure)
self._write_func(struct.pack('!L', len(bytes)))
self._write_func(bytes)
def _write_headers(self, headers):
self._write_prefixed_bencode(headers)
def _write_structure(self, args):
self._write_func('s')
utf8_args = []
for arg in args:
if type(arg) is unicode:
utf8_args.append(arg.encode('utf8'))
else:
utf8_args.append(arg)
self._write_prefixed_bencode(utf8_args)
def _write_end(self):
self._write_func('e')
self.flush()
def _write_prefixed_body(self, bytes):
self._write_func('b')
self._write_func(struct.pack('!L', len(bytes)))
self._write_func(bytes)
def _write_chunked_body_start(self):
self._write_func('oC')
def _write_error_status(self):
self._write_func('oE')
def _write_success_status(self):
self._write_func('oS')
class ProtocolThreeResponder(_ProtocolThreeEncoder):
def __init__(self, write_func):
_ProtocolThreeEncoder.__init__(self, write_func)
self.response_sent = False
self._headers = {'Software version': bzrlib.__version__}
if 'hpss' in debug.debug_flags:
self._thread_id = thread.get_ident()
self._response_start_time = None
def _trace(self, action, message, extra_bytes=None, include_time=False):
if self._response_start_time is None:
self._response_start_time = osutils.timer_func()
if include_time:
t = '%5.3fs ' % (time.clock() - self._response_start_time)
else:
t = ''
if extra_bytes is None:
extra = ''
else:
extra = ' ' + repr(extra_bytes[:40])
if len(extra) > 33:
extra = extra[:29] + extra[-1] + '...'
mutter('%12s: [%s] %s%s%s'
% (action, self._thread_id, t, message, extra))
def send_error(self, exception):
if self.response_sent:
raise AssertionError(
"send_error(%s) called, but response already sent."
% (exception,))
if isinstance(exception, errors.UnknownSmartMethod):
failure = request.FailedSmartServerResponse(
('UnknownMethod', exception.verb))
self.send_response(failure)
return
if 'hpss' in debug.debug_flags:
self._trace('error', str(exception))
self.response_sent = True
self._write_protocol_version()
self._write_headers(self._headers)
self._write_error_status()
self._write_structure(('error', str(exception)))
self._write_end()
def send_response(self, response):
if self.response_sent:
raise AssertionError(
"send_response(%r) called, but response already sent."
% (response,))
self.response_sent = True
self._write_protocol_version()
self._write_headers(self._headers)
if response.is_successful():
self._write_success_status()
else:
self._write_error_status()
if 'hpss' in debug.debug_flags:
self._trace('response', repr(response.args))
self._write_structure(response.args)
if response.body is not None:
self._write_prefixed_body(response.body)
if 'hpss' in debug.debug_flags:
self._trace('body', '%d bytes' % (len(response.body),),
response.body, include_time=True)
elif response.body_stream is not None:
count = num_bytes = 0
first_chunk = None
for exc_info, chunk in _iter_with_errors(response.body_stream):
count += 1
if exc_info is not None:
self._write_error_status()
error_struct = request._translate_error(exc_info[1])
self._write_structure(error_struct)
break
else:
if isinstance(chunk, request.FailedSmartServerResponse):
self._write_error_status()
self._write_structure(chunk.args)
break
num_bytes += len(chunk)
if first_chunk is None:
first_chunk = chunk
self._write_prefixed_body(chunk)
self.flush()
if 'hpssdetail' in debug.debug_flags:
# Not worth timing separately, as _write_func is
# actually buffered
self._trace('body chunk',
'%d bytes' % (len(chunk),),
chunk, suppress_time=True)
if 'hpss' in debug.debug_flags:
self._trace('body stream',
'%d bytes %d chunks' % (num_bytes, count),
first_chunk)
self._write_end()
if 'hpss' in debug.debug_flags:
self._trace('response end', '', include_time=True)
def _iter_with_errors(iterable):
"""Handle errors from iterable.next().
Use like::
for exc_info, value in _iter_with_errors(iterable):
...
This is a safer alternative to::
try:
for value in iterable:
...
except:
...
Because the latter will catch errors from the for-loop body, not just
iterable.next()
If an error occurs, exc_info will be a exc_info tuple, and the generator
will terminate. Otherwise exc_info will be None, and value will be the
value from iterable.next(). Note that KeyboardInterrupt and SystemExit
will not be itercepted.
"""
iterator = iter(iterable)
while True:
try:
yield None, iterator.next()
except StopIteration:
return
except (KeyboardInterrupt, SystemExit):
raise
except Exception:
mutter('_iter_with_errors caught error')
log_exception_quietly()
yield sys.exc_info(), None
return
class ProtocolThreeRequester(_ProtocolThreeEncoder, Requester):
def __init__(self, medium_request):
_ProtocolThreeEncoder.__init__(self, medium_request.accept_bytes)
self._medium_request = medium_request
self._headers = {}
self.body_stream_started = None
def set_headers(self, headers):
self._headers = headers.copy()
def call(self, *args):
if 'hpss' in debug.debug_flags:
mutter('hpss call: %s', repr(args)[1:-1])
base = getattr(self._medium_request._medium, 'base', None)
if base is not None:
mutter(' (to %s)', base)
self._request_start_time = osutils.timer_func()
self._write_protocol_version()
self._write_headers(self._headers)
self._write_structure(args)
self._write_end()
self._medium_request.finished_writing()
def call_with_body_bytes(self, args, body):
"""Make a remote call of args with body bytes 'body'.
After calling this, call read_response_tuple to find the result out.
"""
if 'hpss' in debug.debug_flags:
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
path = getattr(self._medium_request._medium, '_path', None)
if path is not None:
mutter(' (to %s)', path)
mutter(' %d bytes', len(body))
self._request_start_time = osutils.timer_func()
self._write_protocol_version()
self._write_headers(self._headers)
self._write_structure(args)
self._write_prefixed_body(body)
self._write_end()
self._medium_request.finished_writing()
def call_with_body_readv_array(self, args, body):
"""Make a remote call with a readv array.
The body is encoded with one line per readv offset pair. The numbers in
each pair are separated by a comma, and no trailing \\n is emitted.
"""
if 'hpss' in debug.debug_flags:
mutter('hpss call w/readv: %s', repr(args)[1:-1])
path = getattr(self._medium_request._medium, '_path', None)
if path is not None:
mutter(' (to %s)', path)
self._request_start_time = osutils.timer_func()
self._write_protocol_version()
self._write_headers(self._headers)
self._write_structure(args)
readv_bytes = self._serialise_offsets(body)
if 'hpss' in debug.debug_flags:
mutter(' %d bytes in readv request', len(readv_bytes))
self._write_prefixed_body(readv_bytes)
self._write_end()
self._medium_request.finished_writing()
def call_with_body_stream(self, args, stream):
if 'hpss' in debug.debug_flags:
mutter('hpss call w/body stream: %r', args)
path = getattr(self._medium_request._medium, '_path', None)
if path is not None:
mutter(' (to %s)', path)
self._request_start_time = osutils.timer_func()
self.body_stream_started = False
self._write_protocol_version()
self._write_headers(self._headers)
self._write_structure(args)
# TODO: notice if the server has sent an early error reply before we
# have finished sending the stream. We would notice at the end
# anyway, but if the medium can deliver it early then it's good
# to short-circuit the whole request...
# Provoke any ConnectionReset failures before we start the body stream.
self.flush()
self.body_stream_started = True
for exc_info, part in _iter_with_errors(stream):
if exc_info is not None:
# Iterating the stream failed. Cleanly abort the request.
self._write_error_status()
# Currently the client unconditionally sends ('error',) as the
# error args.
self._write_structure(('error',))
self._write_end()
self._medium_request.finished_writing()
raise exc_info[0], exc_info[1], exc_info[2]
else:
self._write_prefixed_body(part)
self.flush()
self._write_end()
self._medium_request.finished_writing()
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