hgext/hooklib/changeset_obsoleted.py

rust: add `dirstate_tree` module

Mercurial needs to represent the filesystem hierarchy on which it operates, for
example in the dirstate. Its current on-disk representation is an unsorted, flat
structure that gets transformed in the current Rust code into a `HashMap`.
This loses the hierarchical information of the dirstate, leading to some
unfortunate performance and algorithmic compromises.

This module adds an implementation of a radix tree that is specialized for
representing the dirstate: its unit is the path component. I have made no
efforts to optimize either its memory footprint or its insertion speed: they're
pretty bad for now.

Following will be a few patches that modify the dirstate.status logic to use
that new hierarchical information, fixing issue 6335 in the same swing.

Differential Revision: https://phab.mercurial-scm.org/D9085

# Copyright 2020 Joerg Sonnenberger <[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.
"""changeset_obsoleted is a hook to send a mail when an
existing draft changeset is obsoleted by an obsmarker without successor.

Correct message threading requires the same messageidseed to be used for both
the original notification and the new mail.

Usage:
  [notify]
  messageidseed = myseed

  [hooks]
  txnclose.changeset_obsoleted = \
    python:hgext.hooklib.changeset_obsoleted.hook
"""

from __future__ import absolute_import

import email.errors as emailerrors
import email.utils as emailutils

from mercurial.i18n import _
from mercurial import (
    encoding,
    error,
    formatter,
    logcmdutil,
    mail,
    obsutil,
    pycompat,
    registrar,
)
from mercurial.utils import dateutil
from .. import notify

configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b'notify_obsoleted', b'domain', default=None,
)
configitem(
    b'notify_obsoleted', b'messageidseed', default=None,
)
configitem(
    b'notify_obsoleted',
    b'template',
    default=b'''Subject: changeset abandoned

This changeset has been abandoned.
''',
)


def _report_commit(ui, repo, ctx):
    domain = ui.config(b'notify_obsoleted', b'domain') or ui.config(
        b'notify', b'domain'
    )
    messageidseed = ui.config(
        b'notify_obsoleted', b'messageidseed'
    ) or ui.config(b'notify', b'messageidseed')
    template = ui.config(b'notify_obsoleted', b'template')
    spec = formatter.literal_templatespec(template)
    templater = logcmdutil.changesettemplater(ui, repo, spec)
    ui.pushbuffer()
    n = notify.notifier(ui, repo, b'incoming')

    subs = set()
    for sub, spec in n.subs:
        if spec is None:
            subs.add(sub)
            continue
        revs = repo.revs(b'%r and %d:', spec, ctx.rev())
        if len(revs):
            subs.add(sub)
            continue
    if len(subs) == 0:
        ui.debug(
            b'notify_obsoleted: no subscribers to selected repo and revset\n'
        )
        return

    templater.show(
        ctx,
        changes=ctx.changeset(),
        baseurl=ui.config(b'web', b'baseurl'),
        root=repo.root,
        webroot=n.root,
    )
    data = ui.popbuffer()

    try:
        msg = mail.parsebytes(data)
    except emailerrors.MessageParseError as inst:
        raise error.Abort(inst)

    msg['In-reply-to'] = notify.messageid(ctx, domain, messageidseed)
    msg['Message-Id'] = notify.messageid(
        ctx, domain, messageidseed + b'-obsoleted'
    )
    msg['Date'] = encoding.strfromlocal(
        dateutil.datestr(format=b"%a, %d %b %Y %H:%M:%S %1%2")
    )
    if not msg['From']:
        sender = ui.config(b'email', b'from') or ui.username()
        if b'@' not in sender or b'@localhost' in sender:
            sender = n.fixmail(sender)
        msg['From'] = mail.addressencode(ui, sender, n.charsets, n.test)
    msg['To'] = ', '.join(sorted(subs))

    msgtext = msg.as_bytes() if pycompat.ispy3 else msg.as_string()
    if ui.configbool(b'notify', b'test'):
        ui.write(msgtext)
        if not msgtext.endswith(b'\n'):
            ui.write(b'\n')
    else:
        ui.status(_(b'notify_obsoleted: sending mail for %d\n') % ctx.rev())
        mail.sendmail(
            ui, emailutils.parseaddr(msg['From'])[1], subs, msgtext, mbox=n.mbox
        )


def has_successor(repo, rev):
    return any(
        r for r in obsutil.allsuccessors(repo.obsstore, [rev]) if r != rev
    )


def hook(ui, repo, hooktype, node=None, **kwargs):
    if hooktype != b"txnclose":
        raise error.Abort(
            _(b'Unsupported hook type %r') % pycompat.bytestr(hooktype)
        )
    for rev in obsutil.getobsoleted(repo, changes=kwargs['changes']):
        ctx = repo.unfiltered()[rev]
        if not has_successor(repo, ctx.node()):
            _report_commit(ui, repo, ctx)