Mercurial > hg
view tests/badserverext.py @ 36672:9e7b14caf67f
xdiff: remove patience and histogram diff algorithms
Patience diff is the normal diff algorithm, plus some greediness that
unconditionally matches common common unique lines. That means it is easy to
construct cases to let it generate suboptimal result, like:
```
open('a', 'w').write('\n'.join(list('a' + 'x' * 300 + 'u' + 'x' * 700 + 'a\n')))
open('b', 'w').write('\n'.join(list('b' + 'x' * 700 + 'u' + 'x' * 300 + 'b\n')))
```
Patience diff has been advertised as being able to generate better results for
some C code changes. However, the more scientific way to do that is the
indention heuristic [1].
Since patience diff could generate suboptimal result more easily and its
"better" diff feature could be replaced by the new indention heuristic, let's
just remove it and its variant histogram diff to simplify the code.
[1]: https://github.com/git/git/commit/433860f3d0beb0c6f205290bd16cda413148f098
Test Plan:
`gcc -fPIC *.c --shared -o xdiff.so` still builds.
Differential Revision: https://phab.mercurial-scm.org/D2573
author | Jun Wu <quark@fb.com> |
---|---|
date | Sat, 03 Mar 2018 10:39:55 -0800 |
parents | fb7897e53d49 |
children | aacfca6f9767 |
line wrap: on
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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(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