Mercurial > hg
view tests/badserverext.py @ 36367:043e77f3be09
sshpeer: return framed file object when needed
Currently, wireproto.wirepeer has a default implementation of
_submitbatch() and sshv1peer has a very similar implementation.
The main difference is that sshv1peer is aware of the total amount
of bytes it can read whereas the default implementation reads the
stream until no more data is returned. The default implementation
works for HTTP, since there is a known end to HTTP responses (either
Content-Length or 0 sized chunk).
This commit teaches sshv1peer to use our just-introduced "cappedreader"
class for wrapping a file object to limit the number of bytes that
can be read. We do this by introducing an argument to specify whether
the response is framed. If set, we returned a cappedreader instance
instead of the raw pipe.
_call() always has framed responses. So we set this argument
unconditionally and then .read() the entirety of the result.
Strictly speaking, we don't need to use cappedreader in this case
and can inline frame decoding/read logic. But I like when things
are consistent. The overhead should be negligible.
_callstream() and _callcompressable() are special: whether framing
is used depends on the specific command. So, we define a set
of commands that have framed response. It currently only
contains "batch."
As a result of this change, the one-off implementation of
_submitbatch() in sshv1peer can be removed since it is now
safe to .read() the response's file object until end of stream.
cappedreader takes care of not overrunning the frame.
Differential Revision: https://phab.mercurial-scm.org/D2380
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 21 Feb 2018 08:35:48 -0800 |
parents | c077eac329e2 |
children | fb7897e53d49 |
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# 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('badserver', 'closeafteraccept', default=False, ) configitem('badserver', 'closeafterrecvbytes', default=0, ) configitem('badserver', 'closeaftersendbytes', default=0, ) configitem('badserver', '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