push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
# urllibcompat.py - adapters to ease using urllib2 on Py2 and urllib on Py3
#
# Copyright 2017 Google, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import http.server
import urllib.error
import urllib.parse
import urllib.request
import urllib.response
from . import pycompat
_sysstr = pycompat.sysstr
class _pycompatstub:
def __init__(self):
self._aliases = {}
def _registeraliases(self, origin, items):
"""Add items that will be populated at the first access"""
items = map(_sysstr, items)
self._aliases.update(
(item.replace('_', '').lower(), (origin, item)) for item in items
)
def _registeralias(self, origin, attr, name):
"""Alias ``origin``.``attr`` as ``name``"""
self._aliases[_sysstr(name)] = (origin, _sysstr(attr))
def __getattr__(self, name):
try:
origin, item = self._aliases[name]
except KeyError:
raise AttributeError(name)
self.__dict__[name] = obj = getattr(origin, item)
return obj
httpserver = _pycompatstub()
urlreq = _pycompatstub()
urlerr = _pycompatstub()
urlreq._registeraliases(
urllib.parse,
(
b"splitattr",
b"splitpasswd",
b"splitport",
b"splituser",
b"urlparse",
b"urlunparse",
),
)
urlreq._registeralias(urllib.parse, b"parse_qs", b"parseqs")
urlreq._registeralias(urllib.parse, b"parse_qsl", b"parseqsl")
urlreq._registeralias(urllib.parse, b"unquote_to_bytes", b"unquote")
urlreq._registeraliases(
urllib.request,
(
b"AbstractHTTPHandler",
b"BaseHandler",
b"build_opener",
b"FileHandler",
b"FTPHandler",
b"ftpwrapper",
b"HTTPHandler",
b"HTTPSHandler",
b"install_opener",
b"pathname2url",
b"HTTPBasicAuthHandler",
b"HTTPDigestAuthHandler",
b"HTTPPasswordMgrWithDefaultRealm",
b"ProxyHandler",
b"Request",
b"url2pathname",
b"urlopen",
),
)
urlreq._registeraliases(
urllib.response,
(
b"addclosehook",
b"addinfourl",
),
)
urlerr._registeraliases(
urllib.error,
(
b"HTTPError",
b"URLError",
),
)
httpserver._registeraliases(
http.server,
(
b"HTTPServer",
b"BaseHTTPRequestHandler",
b"SimpleHTTPRequestHandler",
b"CGIHTTPRequestHandler",
),
)
# urllib.parse.quote() accepts both str and bytes, decodes bytes
# (if necessary), and returns str. This is wonky. We provide a custom
# implementation that only accepts bytes and emits bytes.
def quote(s, safe='/'):
# bytestr has an __iter__ that emits characters. quote_from_bytes()
# does an iteration and expects ints. We coerce to bytes to appease it.
if isinstance(s, pycompat.bytestr):
s = bytes(s)
s = urllib.parse.quote_from_bytes(s, safe=safe)
return s.encode('ascii', 'strict')
# urllib.parse.urlencode() returns str. We use this function to make
# sure we return bytes.
def urlencode(query, doseq=False):
s = urllib.parse.urlencode(query, doseq=doseq)
return s.encode('ascii')
urlreq.quote = quote
urlreq.urlencode = urlencode
def getfullurl(req):
return req.full_url
def gethost(req):
return req.host
def getselector(req):
return req.selector
def getdata(req):
return req.data
def hasdata(req):
return req.data is not None