hgext/schemes.py

rust-update: make `update_from_null` respect `worker.numcpu` config option

This was overlooked in the original series.

This is important for tests (because we run many at once), and for the
occasional end user that wants to keep their CPU usage in check.

A future series should clean up this `worker` parameter tunelling business by
rewriting the config in Rust, but doing so on stable would be a very bad
idea.

# Copyright 2009, Alexander Solovyov <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""extend schemes with shortcuts to repository swarms

This extension allows you to specify shortcuts for parent URLs with a
lot of repositories to act like a scheme, for example::

  [schemes]
  py = http://code.python.org/hg/

After that you can use it like::

  hg clone py://trunk/

Additionally there is support for some more complex schemas, for
example used by Google Code::

  [schemes]
  gcode = http://{1}.googlecode.com/hg/

The syntax is taken from Mercurial templates, and you have unlimited
number of variables, starting with ``{1}`` and continuing with
``{2}``, ``{3}`` and so on. This variables will receive parts of URL
supplied, split by ``/``. Anything not specified as ``{part}`` will be
just appended to an URL.

For convenience, the extension adds these schemes by default::

  [schemes]
  py = http://hg.python.org/
  bb = https://bitbucket.org/
  bb+ssh = ssh://[e-mail]/
  gcode = https://{1}.googlecode.com/hg/
  kiln = https://{1}.kilnhg.com/Repo/

You can override a predefined scheme by defining a new scheme with the
same name.
"""

from __future__ import annotations

import os
import re

from mercurial.i18n import _
from mercurial import (
    error,
    extensions,
    hg,
    pycompat,
    registrar,
    templater,
)
from mercurial.utils import (
    urlutil,
)

cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'

_partre = re.compile(br'{(\d+)\}')


class ShortRepository:
    def __init__(self, url, scheme, templater):
        self.scheme = scheme
        self.templater = templater
        self.url = url
        try:
            self.parts = max(map(int, _partre.findall(self.url)))
        except ValueError:
            self.parts = 0

    def __repr__(self):
        return b'<ShortRepository: %s>' % self.scheme

    def make_peer(self, ui, path, *args, **kwargs):
        new_url = self.resolve(path.rawloc)
        path = path.copy(new_raw_location=new_url)
        cls = hg.peer_schemes.get(path.url.scheme)
        if cls is not None:
            return cls.make_peer(ui, path, *args, **kwargs)
        return None

    def instance(self, ui, url, create, intents=None, createopts=None):
        url = self.resolve(url)
        u = urlutil.url(url)
        scheme = u.scheme or b'file'
        if scheme in hg.peer_schemes:
            cls = hg.peer_schemes[scheme]
        elif scheme in hg.repo_schemes:
            cls = hg.repo_schemes[scheme]
        else:
            cls = hg.LocalFactory
        return cls.instance(
            ui, url, create, intents=intents, createopts=createopts
        )

    def resolve(self, url):
        # Should this use the urlutil.url class, or is manual parsing better?
        try:
            url = url.split(b'://', 1)[1]
        except IndexError:
            raise error.Abort(_(b"no '://' in scheme url '%s'") % url)
        parts = url.split(b'/', self.parts)
        if len(parts) > self.parts:
            tail = parts[-1]
            parts = parts[:-1]
        else:
            tail = b''
        context = {b'%d' % (i + 1): v for i, v in enumerate(parts)}
        return b''.join(self.templater.process(self.url, context)) + tail


def hasdriveletter(orig, path):
    if path:
        for scheme in schemes:
            if path.startswith(scheme + b':'):
                return False
    return orig(path)


schemes = {
    b'py': b'http://hg.python.org/',
    b'bb': b'https://bitbucket.org/',
    b'bb+ssh': b'ssh://[e-mail]/',
    b'gcode': b'https://{1}.googlecode.com/hg/',
    b'kiln': b'https://{1}.kilnhg.com/Repo/',
}


def _check_drive_letter(scheme: bytes) -> None:
    """check if a scheme conflict with a Windows drive letter"""
    if (
        pycompat.iswindows
        and len(scheme) == 1
        and scheme.isalpha()
        and os.path.exists(b'%s:\\' % scheme)
    ):
        msg = _(b'custom scheme %s:// conflicts with drive letter %s:\\\n')
        msg %= (scheme, scheme.upper())
        raise error.Abort(msg)


def extsetup(ui):
    schemes.update(dict(ui.configitems(b'schemes')))
    t = templater.engine(templater.parse)
    for scheme, url in schemes.items():
        _check_drive_letter(scheme)
        url_scheme = urlutil.url(url).scheme
        if url_scheme in hg.peer_schemes:
            hg.peer_schemes[scheme] = ShortRepository(url, scheme, t)
        else:
            hg.repo_schemes[scheme] = ShortRepository(url, scheme, t)

    extensions.wrapfunction(urlutil, 'hasdriveletter', hasdriveletter)


@command(b'debugexpandscheme', norepo=True)
def expandscheme(ui, url, **opts):
    """given a repo path, provide the scheme-expanded path"""
    scheme = urlutil.url(url).scheme
    if scheme in hg.peer_schemes:
        cls = hg.peer_schemes[scheme]
    else:
        cls = hg.repo_schemes.get(scheme)
    if cls is not None and isinstance(cls, ShortRepository):
        url = cls.resolve(url)
    ui.write(url + b'\n')