##// END OF EJS Templates
tests: add tests for poorly behaving HTTP server...
tests: add tests for poorly behaving HTTP server I've spent several hours over the past few weeks investigating networking failures involving hg.mozilla.org. As part of this, it has become clear that the Mercurial client's error handling when it encounters network failures is far from robust. To prove this is true, I've devised a battery of tests simulating various network failures, notably premature connection closes. To achieve this, I've implemented an extension that monkeypatches the built-in HTTP server and hooks in at the socket level and allows various events to occur based on config options. For example, you can refuse to accept() a client socket or you can close() the socket after N bytes have been sent or received. The latter effectively simulates an unexpected connection drop (and these occur all the time in the real world). The new test file launches servers exhibiting various "bad" behaviors and points a client at them. As the many TODO comments in the test call attention to, Mercurial often displays unhelpful errors when network-related failures occur. This makes it difficult for users to understand what's going on and difficult for server administrators to pinpoint root causes without packet tracing. Upcoming patches will attempt to fix these error handling deficiencies.

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request.py
152 lines | 5.3 KiB | text/x-python | PythonLexer
# hgweb/request.py - An http request from either CGI or the standalone server.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import cgi
import errno
import socket
from .common import (
ErrorResponse,
HTTP_NOT_MODIFIED,
statusmessage,
)
from .. import (
util,
)
shortcuts = {
'cl': [('cmd', ['changelog']), ('rev', None)],
'sl': [('cmd', ['shortlog']), ('rev', None)],
'cs': [('cmd', ['changeset']), ('node', None)],
'f': [('cmd', ['file']), ('filenode', None)],
'fl': [('cmd', ['filelog']), ('filenode', None)],
'fd': [('cmd', ['filediff']), ('node', None)],
'fa': [('cmd', ['annotate']), ('filenode', None)],
'mf': [('cmd', ['manifest']), ('manifest', None)],
'ca': [('cmd', ['archive']), ('node', None)],
'tags': [('cmd', ['tags'])],
'tip': [('cmd', ['changeset']), ('node', ['tip'])],
'static': [('cmd', ['static']), ('file', None)]
}
def normalize(form):
# first expand the shortcuts
for k in shortcuts.iterkeys():
if k in form:
for name, value in shortcuts[k]:
if value is None:
value = form[k]
form[name] = value
del form[k]
# And strip the values
for k, v in form.iteritems():
form[k] = [i.strip() for i in v]
return form
class wsgirequest(object):
"""Higher-level API for a WSGI request.
WSGI applications are invoked with 2 arguments. They are used to
instantiate instances of this class, which provides higher-level APIs
for obtaining request parameters, writing HTTP output, etc.
"""
def __init__(self, wsgienv, start_response):
version = wsgienv['wsgi.version']
if (version < (1, 0)) or (version >= (2, 0)):
raise RuntimeError("Unknown and unsupported WSGI version %d.%d"
% version)
self.inp = wsgienv['wsgi.input']
self.err = wsgienv['wsgi.errors']
self.threaded = wsgienv['wsgi.multithread']
self.multiprocess = wsgienv['wsgi.multiprocess']
self.run_once = wsgienv['wsgi.run_once']
self.env = wsgienv
self.form = normalize(cgi.parse(self.inp,
self.env,
keep_blank_values=1))
self._start_response = start_response
self.server_write = None
self.headers = []
def __iter__(self):
return iter([])
def read(self, count=-1):
return self.inp.read(count)
def drain(self):
'''need to read all data from request, httplib is half-duplex'''
length = int(self.env.get('CONTENT_LENGTH') or 0)
for s in util.filechunkiter(self.inp, limit=length):
pass
def respond(self, status, type, filename=None, body=None):
if self._start_response is not None:
self.headers.append(('Content-Type', type))
if filename:
filename = (filename.rpartition('/')[-1]
.replace('\\', '\\\\').replace('"', '\\"'))
self.headers.append(('Content-Disposition',
'inline; filename="%s"' % filename))
if body is not None:
self.headers.append(('Content-Length', str(len(body))))
for k, v in self.headers:
if not isinstance(v, str):
raise TypeError('header value must be string: %r' % (v,))
if isinstance(status, ErrorResponse):
self.headers.extend(status.headers)
if status.code == HTTP_NOT_MODIFIED:
# RFC 2616 Section 10.3.5: 304 Not Modified has cases where
# it MUST NOT include any headers other than these and no
# body
self.headers = [(k, v) for (k, v) in self.headers if
k in ('Date', 'ETag', 'Expires',
'Cache-Control', 'Vary')]
status = statusmessage(status.code, str(status))
elif status == 200:
status = '200 Script output follows'
elif isinstance(status, int):
status = statusmessage(status)
self.server_write = self._start_response(status, self.headers)
self._start_response = None
self.headers = []
if body is not None:
self.write(body)
self.server_write = None
def write(self, thing):
if thing:
try:
self.server_write(thing)
except socket.error as inst:
if inst[0] != errno.ECONNRESET:
raise
def writelines(self, lines):
for line in lines:
self.write(line)
def flush(self):
return None
def close(self):
return None
def wsgiapplication(app_maker):
'''For compatibility with old CGI scripts. A plain hgweb() or hgwebdir()
can and should now be used as a WSGI application.'''
application = app_maker()
def run_wsgi(env, respond):
return application(env, respond)
return run_wsgi