wireproto: use CBOR for command requests
Now that we're using CBOR in the new wire protocol, let's convert
command requests to it.
Before I wrote this patch and was even thinking about CBOR, I was
thinking about how commands should be issued and came to the
conclusion that we didn't need separate frames to represent the
command name from its arguments. I already had a partially
completed patch prepared to merge the frames.
But with CBOR, it makes the implementation a bit simpler because
we don't need to roll our own serialization.
The changes here are a bit invasive. I tried to split this into
multiple commits to make it easier to review. But it was just too
hard.
* "command name" and "command argument" frames have been collapsed
into a "command request" frame.
* The flags for this new frame are totally different.
* Frame processing has been overhauled to reflect the new order
of things.
* Test fallout was significant. A handful of tests were removed.
Altogether, I think the new code is simpler. We don't have
complicated state around receiving commands. We're either receiving
command request frames or command data frames. We /could/
potentially collapse command data frames into command request
frames. Although I'd have to think a bit more about this before
I do it.
Differential Revision: https://phab.mercurial-scm.org/D2951
# badserverext.py - Extension making servers behave badly
#
# Copyright 2017 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
# no-check-code
"""Extension to make servers behave badly.
This extension is useful for testing Mercurial behavior when various network
events occur.
Various config options in the [badserver] section influence behavior:
closebeforeaccept
If true, close() the server socket when a new connection arrives before
accept() is called. The server will then exit.
closeafteraccept
If true, the server will close() the client socket immediately after
accept().
closeafterrecvbytes
If defined, close the client socket after receiving this many bytes.
closeaftersendbytes
If defined, close the client socket after sending this many bytes.
"""
from __future__ import absolute_import
import socket
from mercurial import(
registrar,
)
from mercurial.hgweb import (
server,
)
configtable = {}
configitem = registrar.configitem(configtable)
configitem(b'badserver', b'closeafteraccept',
default=False,
)
configitem(b'badserver', b'closeafterrecvbytes',
default=0,
)
configitem(b'badserver', b'closeaftersendbytes',
default=0,
)
configitem(b'badserver', b'closebeforeaccept',
default=False,
)
# We can't adjust __class__ on a socket instance. So we define a proxy type.
class socketproxy(object):
__slots__ = (
'_orig',
'_logfp',
'_closeafterrecvbytes',
'_closeaftersendbytes',
)
def __init__(self, obj, logfp, closeafterrecvbytes=0,
closeaftersendbytes=0):
object.__setattr__(self, '_orig', obj)
object.__setattr__(self, '_logfp', logfp)
object.__setattr__(self, '_closeafterrecvbytes', closeafterrecvbytes)
object.__setattr__(self, '_closeaftersendbytes', closeaftersendbytes)
def __getattribute__(self, name):
if name in ('makefile',):
return object.__getattribute__(self, name)
return getattr(object.__getattribute__(self, '_orig'), name)
def __delattr__(self, name):
delattr(object.__getattribute__(self, '_orig'), name)
def __setattr__(self, name, value):
setattr(object.__getattribute__(self, '_orig'), name, value)
def makefile(self, mode, bufsize):
f = object.__getattribute__(self, '_orig').makefile(mode, bufsize)
logfp = object.__getattribute__(self, '_logfp')
closeafterrecvbytes = object.__getattribute__(self,
'_closeafterrecvbytes')
closeaftersendbytes = object.__getattribute__(self,
'_closeaftersendbytes')
return fileobjectproxy(f, logfp,
closeafterrecvbytes=closeafterrecvbytes,
closeaftersendbytes=closeaftersendbytes)
# We can't adjust __class__ on socket._fileobject, so define a proxy.
class fileobjectproxy(object):
__slots__ = (
'_orig',
'_logfp',
'_closeafterrecvbytes',
'_closeaftersendbytes',
)
def __init__(self, obj, logfp, closeafterrecvbytes=0,
closeaftersendbytes=0):
object.__setattr__(self, '_orig', obj)
object.__setattr__(self, '_logfp', logfp)
object.__setattr__(self, '_closeafterrecvbytes', closeafterrecvbytes)
object.__setattr__(self, '_closeaftersendbytes', closeaftersendbytes)
def __getattribute__(self, name):
if name in ('read', 'readline', 'write', '_writelog'):
return object.__getattribute__(self, name)
return getattr(object.__getattribute__(self, '_orig'), name)
def __delattr__(self, name):
delattr(object.__getattribute__(self, '_orig'), name)
def __setattr__(self, name, value):
setattr(object.__getattribute__(self, '_orig'), name, value)
def _writelog(self, msg):
msg = msg.replace('\r', '\\r').replace('\n', '\\n')
object.__getattribute__(self, '_logfp').write(msg)
object.__getattribute__(self, '_logfp').write('\n')
object.__getattribute__(self, '_logfp').flush()
def read(self, size=-1):
remaining = object.__getattribute__(self, '_closeafterrecvbytes')
# No read limit. Call original function.
if not remaining:
result = object.__getattribute__(self, '_orig').read(size)
self._writelog('read(%d) -> (%d) (%s) %s' % (size,
len(result),
result))
return result
origsize = size
if size < 0:
size = remaining
else:
size = min(remaining, size)
result = object.__getattribute__(self, '_orig').read(size)
remaining -= len(result)
self._writelog('read(%d from %d) -> (%d) %s' % (
size, origsize, len(result), result))
object.__setattr__(self, '_closeafterrecvbytes', remaining)
if remaining <= 0:
self._writelog('read limit reached, closing socket')
self._sock.close()
# This is the easiest way to abort the current request.
raise Exception('connection closed after receiving N bytes')
return result
def readline(self, size=-1):
remaining = object.__getattribute__(self, '_closeafterrecvbytes')
# No read limit. Call original function.
if not remaining:
result = object.__getattribute__(self, '_orig').readline(size)
self._writelog('readline(%d) -> (%d) %s' % (
size, len(result), result))
return result
origsize = size
if size < 0:
size = remaining
else:
size = min(remaining, size)
result = object.__getattribute__(self, '_orig').readline(size)
remaining -= len(result)
self._writelog('readline(%d from %d) -> (%d) %s' % (
size, origsize, len(result), result))
object.__setattr__(self, '_closeafterrecvbytes', remaining)
if remaining <= 0:
self._writelog('read limit reached; closing socket')
self._sock.close()
# This is the easiest way to abort the current request.
raise Exception('connection closed after receiving N bytes')
return result
def write(self, data):
remaining = object.__getattribute__(self, '_closeaftersendbytes')
# No byte limit on this operation. Call original function.
if not remaining:
self._writelog('write(%d) -> %s' % (len(data), data))
result = object.__getattribute__(self, '_orig').write(data)
return result
if len(data) > remaining:
newdata = data[0:remaining]
else:
newdata = data
remaining -= len(newdata)
self._writelog('write(%d from %d) -> (%d) %s' % (
len(newdata), len(data), remaining, newdata))
result = object.__getattribute__(self, '_orig').write(newdata)
object.__setattr__(self, '_closeaftersendbytes', remaining)
if remaining <= 0:
self._writelog('write limit reached; closing socket')
self._sock.close()
raise Exception('connection closed after sending N bytes')
return result
def extsetup(ui):
# Change the base HTTP server class so various events can be performed.
# See SocketServer.BaseServer for how the specially named methods work.
class badserver(server.MercurialHTTPServer):
def __init__(self, ui, *args, **kwargs):
self._ui = ui
super(badserver, self).__init__(ui, *args, **kwargs)
# Need to inherit object so super() works.
class badrequesthandler(self.RequestHandlerClass, object):
def send_header(self, name, value):
# Make headers deterministic to facilitate testing.
if name.lower() == 'date':
value = 'Fri, 14 Apr 2017 00:00:00 GMT'
elif name.lower() == 'server':
value = 'badhttpserver'
return super(badrequesthandler, self).send_header(name,
value)
self.RequestHandlerClass = badrequesthandler
# Called to accept() a pending socket.
def get_request(self):
if self._ui.configbool('badserver', 'closebeforeaccept'):
self.socket.close()
# Tells the server to stop processing more requests.
self.__shutdown_request = True
# Simulate failure to stop processing this request.
raise socket.error('close before accept')
if self._ui.configbool('badserver', 'closeafteraccept'):
request, client_address = super(badserver, self).get_request()
request.close()
raise socket.error('close after accept')
return super(badserver, self).get_request()
# Does heavy lifting of processing a request. Invokes
# self.finish_request() which calls self.RequestHandlerClass() which
# is a hgweb.server._httprequesthandler.
def process_request(self, socket, address):
# Wrap socket in a proxy if we need to count bytes.
closeafterrecvbytes = self._ui.configint('badserver',
'closeafterrecvbytes')
closeaftersendbytes = self._ui.configint('badserver',
'closeaftersendbytes')
if closeafterrecvbytes or closeaftersendbytes:
socket = socketproxy(socket, self.errorlog,
closeafterrecvbytes=closeafterrecvbytes,
closeaftersendbytes=closeaftersendbytes)
return super(badserver, self).process_request(socket, address)
server.MercurialHTTPServer = badserver