view contrib/phab-clean.py @ 49000:dd6b67d5c256 stable

rust: fix unsound `OwningDirstateMap`

As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.

The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.

I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.

In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.

Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.

Differential Revision: https://phab.mercurial-scm.org/D12429

#!/usr/bin/env python3
#
# A small script to automatically reject idle Diffs
#
# you need to set the PHABBOT_USER and PHABBOT_TOKEN environment variable for authentication
from __future__ import absolute_import, print_function

import datetime
import os
import sys

import phabricator

MESSAGE = """There seems to have been no activities on this Diff for the past 3 Months.

By policy, we are automatically moving it out of the `need-review` state.

Please, move it back to `need-review` without hesitation if this diff should still be discussed.

:baymax:need-review-idle:
"""


PHAB_URL = "https://phab.mercurial-scm.org/api/"
USER = os.environ.get("PHABBOT_USER", "baymax")
TOKEN = os.environ.get("PHABBOT_TOKEN")


NOW = datetime.datetime.now()

# 3 months in seconds
DELAY = 60 * 60 * 24 * 30 * 3


def get_all_diff(phab):
    """Fetch all the diff that the need review"""
    return phab.differential.query(
        status="status-needs-review",
        order="order-modified",
        paths=[('HG', None)],
    )


def filter_diffs(diffs, older_than):
    """filter diffs to only keep the one unmodified sin <older_than> seconds"""
    olds = []
    for d in diffs:
        modified = int(d['dateModified'])
        modified = datetime.datetime.fromtimestamp(modified)
        d["idleFor"] = idle_for = NOW - modified
        if idle_for.total_seconds() > older_than:
            olds.append(d)
    return olds


def nudge_diff(phab, diff):
    """Comment on the idle diff and reject it"""
    diff_id = int(d['id'])
    phab.differential.createcomment(
        revision_id=diff_id, message=MESSAGE, action="reject"
    )


if not USER:
    print(
        "not user specified please set PHABBOT_USER and PHABBOT_TOKEN",
        file=sys.stderr,
    )
elif not TOKEN:
    print(
        "not api-token specified please set PHABBOT_USER and PHABBOT_TOKEN",
        file=sys.stderr,
    )
    sys.exit(1)

phab = phabricator.Phabricator(USER, host=PHAB_URL, token=TOKEN)
phab.connect()
phab.update_interfaces()
print('Hello "%s".' % phab.user.whoami()['realName'])

diffs = get_all_diff(phab)
print("Found %d Diffs" % len(diffs))
olds = filter_diffs(diffs, DELAY)
print("Found %d old Diffs" % len(olds))
for d in olds:
    diff_id = d['id']
    status = d['statusName']
    modified = int(d['dateModified'])
    idle_for = d["idleFor"]
    msg = 'nudging D%s in "%s" state for %s'
    print(msg % (diff_id, status, idle_for))
    # uncomment to actually affect phab
    nudge_diff(phab, d)