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wireprotov2: define and implement "manifestdata" command...
wireprotov2: define and implement "manifestdata" command The added command can be used for obtaining manifest data. Given a manifest path and set of manifest nodes, data about manifests can be retrieved. Unlike changeset data, we wish to emit deltas to describe manifest revisions. So the command uses the relatively new API for building delta requests and emitting them. The code calls into deltaparent(), which I'm not very keen of. There's still work to be done in delta generation land so implementation details of storage (e.g. exactly one delta is stored/available) don't creep into higher levels. But we can worry about this later (there is already a TODO on imanifestorage tracking this). On the subject of parent deltas, the server assumes parent revisions exist on the receiving end. This is obviously wrong for shallow clone. I've added TODOs to add a mechanism to the command to allow clients to specify desired behavior. This shouldn't be too difficult to implement. Another big change is that the client must explicitly request manifest nodes to retrieve. This is a major departure from "getbundle," where the server derives relevant manifests as it iterates changesets and sends them automatically. As implemented, the client must transmit each requested node to the server. At 20 bytes per node, we're looking at 2 MB per 100,000 nodes. Plus wire encoding overhead. This isn't ideal for clients with limited upload bandwidth. I plan to address this in the future by allowing alternate mechanisms for defining the revisions to retrieve. One idea is to define a range of changeset revisions whose manifest revisions to retrieve (similar to how "changesetdata" works). We almost certainly want an API to look up an individual manifest by node. And that's where I've chosen to start with the implementation. Again, a theme of this early exchangev2 work is I want to start by building primitives for accessing raw repository data first and see how far we can get with those before we need more complexity. Differential Revision: https://phab.mercurial-scm.org/D4488

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badserverext.py
301 lines | 10.5 KiB | text/x-python | PythonLexer
# 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)
recvbytes = self._ui.config(b'badserver', b'closeafterrecvbytes')
recvbytes = recvbytes.split(',')
self.closeafterrecvbytes = [int(v) for v in recvbytes if v]
sendbytes = self._ui.config(b'badserver', b'closeaftersendbytes')
sendbytes = sendbytes.split(',')
self.closeaftersendbytes = [int(v) for v in sendbytes if v]
# 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(b'badserver', b'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.
if self.closeafterrecvbytes:
closeafterrecvbytes = self.closeafterrecvbytes.pop(0)
else:
closeafterrecvbytes = 0
if self.closeaftersendbytes:
closeaftersendbytes = self.closeaftersendbytes.pop(0)
else:
closeaftersendbytes = 0
if closeafterrecvbytes or closeaftersendbytes:
socket = socketproxy(socket, self.errorlog,
closeafterrecvbytes=closeafterrecvbytes,
closeaftersendbytes=closeaftersendbytes)
return super(badserver, self).process_request(socket, address)
server.MercurialHTTPServer = badserver