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.
# configitems.py - centralized declaration of configuration option
#
# Copyright 2017 Pierre-Yves David <pierre-yves.david@octobus.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import functools
import re
from .utils import resourceutil
from . import (
encoding,
error,
)
try:
import tomllib # pytype: disable=import-error
tomllib.load # trigger lazy import
except ModuleNotFoundError:
# Python <3.11 compat
from .thirdparty import tomli as tomllib
def loadconfigtable(ui, extname, configtable):
"""update config item known to the ui with the extension ones"""
for section, items in sorted(configtable.items()):
knownitems = ui._knownconfig.setdefault(section, itemregister())
knownkeys = set(knownitems)
newkeys = set(items)
for key in sorted(knownkeys & newkeys):
msg = b"extension '%s' overwrites config item '%s.%s'"
msg %= (extname, section, key)
ui.develwarn(msg, config=b'warn-config')
knownitems.update(items)
class configitem:
"""represent a known config item
:section: the official config section where to find this item,
:name: the official name within the section,
:default: default value for this item,
:alias: optional list of tuples as alternatives,
:generic: this is a generic definition, match name using regular expression.
"""
def __init__(
self,
section,
name,
default=None,
alias=(),
generic=False,
priority=0,
experimental=False,
documentation="",
in_core_extension=None,
):
self.section = section
self.name = name
self.default = default
self.documentation = documentation
self.alias = list(alias)
self.generic = generic
self.priority = priority
self.experimental = experimental
self._re = None
self.in_core_extension = in_core_extension
if generic:
self._re = re.compile(self.name)
class itemregister(dict):
"""A specialized dictionary that can handle wild-card selection"""
def __init__(self):
super(itemregister, self).__init__()
self._generics = set()
def update(self, other): # pytype: disable=signature-mismatch
super(itemregister, self).update(other)
self._generics.update(other._generics)
def __setitem__(self, key, item):
super(itemregister, self).__setitem__(key, item)
if item.generic:
self._generics.add(item)
def get(self, key):
baseitem = super(itemregister, self).get(key)
if baseitem is not None and not baseitem.generic:
return baseitem
# search for a matching generic item
generics = sorted(self._generics, key=(lambda x: (x.priority, x.name)))
for item in generics:
# we use 'match' instead of 'search' to make the matching simpler
# for people unfamiliar with regular expression. Having the match
# rooted to the start of the string will produce less surprising
# result for user writing simple regex for sub-attribute.
#
# For example using "color\..*" match produces an unsurprising
# result, while using search could suddenly match apparently
# unrelated configuration that happens to contains "color."
# anywhere. This is a tradeoff where we favor requiring ".*" on
# some match to avoid the need to prefix most pattern with "^".
# The "^" seems more error prone.
if item._re.match(key):
return item
return None
def sanitize_item(item):
"""Apply the transformations that are encoded on top of the pure data"""
# Set the special defaults
default_type_key = "default-type"
default_type = item.pop(default_type_key, None)
if default_type == "dynamic":
item["default"] = dynamicdefault
elif default_type == "list_type":
item["default"] = list
elif default_type == "lambda":
assert isinstance(item["default"], list)
default = [e.encode() for e in item["default"]]
item["default"] = lambda: default
elif default_type == "lazy_module":
item["default"] = lambda: encoding.encoding
else:
if default_type is not None:
msg = "invalid default config type %r for '%s.%s'"
msg %= (default_type, item["section"], item["name"])
raise error.ProgrammingError(msg)
# config expects bytes
alias = item.get("alias")
if alias:
item["alias"] = [(k.encode(), v.encode()) for (k, v) in alias]
if isinstance(item.get("default"), str):
item["default"] = item["default"].encode()
item["section"] = item["section"].encode()
item["name"] = item["name"].encode()
def read_configitems_file():
"""Returns the deserialized TOML structure from the configitems file"""
with resourceutil.open_resource(b"mercurial", b"configitems.toml") as fp:
return tomllib.load(fp)
def configitems_from_toml(items):
"""Register the configitems from the *deserialized* toml file"""
for item in items["items"]:
sanitize_item(item)
coreconfigitem(**item)
templates = items["templates"]
for application in items["template-applications"]:
template_items = templates[application["template"]]
for template_item in template_items:
item = template_item.copy()
prefix = application.get("prefix", "")
item["section"] = application["section"]
if prefix:
item["name"] = f'{prefix}.{item["suffix"]}'
else:
item["name"] = item["suffix"]
sanitize_item(item)
item.pop("suffix", None)
coreconfigitem(**item)
def import_configitems_from_file():
as_toml = read_configitems_file()
configitems_from_toml(as_toml)
coreitems = {}
def _register(configtable, *args, **kwargs):
item = configitem(*args, **kwargs)
section = configtable.setdefault(item.section, itemregister())
if item.name in section:
msg = b"duplicated config item registration for '%s.%s'"
raise error.ProgrammingError(msg % (item.section, item.name))
section[item.name] = item
# special value for case where the default is derived from other values
dynamicdefault = object()
# Registering actual config items
def getitemregister(configtable):
f = functools.partial(_register, configtable)
# export pseudo enum as configitem.*
f.dynamicdefault = dynamicdefault
return f
coreconfigitem = getitemregister(coreitems)
import_configitems_from_file()