annotate mercurial/hbisect.py @ 37210:2a2ce93e12f4

templatefuncs: add mailmap template function

This commit adds a template function to support the .mailmap file
in Mercurial repositories. The .mailmap file comes from git, and
can be used to map new emails and names for old commits. The general
use case is that someone may change their name or author commits
under different emails and aliases, which would make these
commits appear as though they came from different persons. The
file allows you to specify the correct name that should be used
in place of the author field specified in the commit.

The mailmap file has 4 possible formats used to map old "commit"
names to new "proper" names:

1. <[e-mail]> <[e-mail]>
2. Proper Name <[e-mail]>
3. Proper Name <[e-mail]> <[e-mail]>
4. Proper Name <[e-mail]> Commit Name <[e-mail]>

Essentially there is a commit email present in each mailmap entry,
that maps to either an updated name, email, or both. The final
possible format allows commits authored by a person who used
both an old name and an old email to map to a new name and email.

To parse the file, we split by spaces and build a name out
of every element that does not start with "<". Once we find an element
that does start with "<" we concatenate all the name elements that preceded
and add that as a parsed name. We then add the email as the first
parsed email. We repeat the process until the end of the line, or
a comment is found. We will be left with all parsed names in a list,
and all parsed emails in a list, with the 0 index being the proper
values and the 1 index being the commit values (if they were specified
in the entry).

The commit values are added as the keys to a dict, and with the proper
fields as the values. The mapname function takes the mapping object and
the commit author field and attempts to look for a corresponding entry.
To do so we try (commit name, commit email) first, and if no results are
returned then (None, commit email) is also looked up. This is due to
format 4 from above, where someone may have a mailmap entry with both
name and email, and if they don't it is possible they have an entry that
uses only the commit email.

Differential Revision: https://phab.mercurial-scm.org/D2904

# changelog bisection for mercurial
#
# Copyright 2007 Matt Mackall
# Copyright 2005, 2006 Benoit Boissinot <[e-mail]>
#
# Inspired by git bisect, extension skeleton taken from mq.py.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import collections

from .i18n import _
from .node import (
    hex,
    short,
)
from . import (
    error,
)

def bisect(repo, state):
    """find the next node (if any) for testing during a bisect search.
    returns a (nodes, number, good) tuple.

    'nodes' is the final result of the bisect if 'number' is 0.
    Otherwise 'number' indicates the remaining possible candidates for
    the search and 'nodes' contains the next bisect target.
    'good' is True if bisect is searching for a first good changeset, False
    if searching for a first bad one.
    """

    changelog = repo.changelog
    clparents = changelog.parentrevs
    skip = set([changelog.rev(n) for n in state['skip']])

    def buildancestors(bad, good):
        badrev = min([changelog.rev(n) for n in bad])
        ancestors = collections.defaultdict(lambda: None)
        for rev in repo.revs("descendants(%ln) - ancestors(%ln)", good, good):
            ancestors[rev] = []
        if ancestors[badrev] is None:
            return badrev, None
        return badrev, ancestors

    good = False
    badrev, ancestors = buildancestors(state['bad'], state['good'])
    if not ancestors: # looking for bad to good transition?
        good = True
        badrev, ancestors = buildancestors(state['good'], state['bad'])
    bad = changelog.node(badrev)
    if not ancestors: # now we're confused
        if (len(state['bad']) == 1 and len(state['good']) == 1 and
            state['bad'] != state['good']):
            raise error.Abort(_("starting revisions are not directly related"))
        raise error.Abort(_("inconsistent state, %d:%s is good and bad")
                         % (badrev, short(bad)))

    # build children dict
    children = {}
    visit = collections.deque([badrev])
    candidates = []
    while visit:
        rev = visit.popleft()
        if ancestors[rev] == []:
            candidates.append(rev)
            for prev in clparents(rev):
                if prev != -1:
                    if prev in children:
                        children[prev].append(rev)
                    else:
                        children[prev] = [rev]
                        visit.append(prev)

    candidates.sort()
    # have we narrowed it down to one entry?
    # or have all other possible candidates besides 'bad' have been skipped?
    tot = len(candidates)
    unskipped = [c for c in candidates if (c not in skip) and (c != badrev)]
    if tot == 1 or not unskipped:
        return ([changelog.node(c) for c in candidates], 0, good)
    perfect = tot // 2

    # find the best node to test
    best_rev = None
    best_len = -1
    poison = set()
    for rev in candidates:
        if rev in poison:
            # poison children
            poison.update(children.get(rev, []))
            continue

        a = ancestors[rev] or [rev]
        ancestors[rev] = None

        x = len(a) # number of ancestors
        y = tot - x # number of non-ancestors
        value = min(x, y) # how good is this test?
        if value > best_len and rev not in skip:
            best_len = value
            best_rev = rev
            if value == perfect: # found a perfect candidate? quit early
                break

        if y < perfect and rev not in skip: # all downhill from here?
            # poison children
            poison.update(children.get(rev, []))
            continue

        for c in children.get(rev, []):
            if ancestors[c]:
                ancestors[c] = list(set(ancestors[c] + a))
            else:
                ancestors[c] = a + [c]

    assert best_rev is not None
    best_node = changelog.node(best_rev)

    return ([best_node], tot, good)

def extendrange(repo, state, nodes, good):
    # bisect is incomplete when it ends on a merge node and
    # one of the parent was not checked.
    parents = repo[nodes[0]].parents()
    if len(parents) > 1:
        if good:
            side = state['bad']
        else:
            side = state['good']
        num = len(set(i.node() for i in parents) & set(side))
        if num == 1:
            return parents[0].ancestor(parents[1])
    return None

def load_state(repo):
    state = {'current': [], 'good': [], 'bad': [], 'skip': []}
    for l in repo.vfs.tryreadlines("bisect.state"):
        kind, node = l[:-1].split()
        node = repo.lookup(node)
        if kind not in state:
            raise error.Abort(_("unknown bisect kind %s") % kind)
        state[kind].append(node)
    return state


def save_state(repo, state):
    f = repo.vfs("bisect.state", "w", atomictemp=True)
    with repo.wlock():
        for kind in sorted(state):
            for node in state[kind]:
                f.write("%s %s\n" % (kind, hex(node)))
        f.close()

def resetstate(repo):
    """remove any bisect state from the repository"""
    if repo.vfs.exists("bisect.state"):
        repo.vfs.unlink("bisect.state")

def checkstate(state):
    """check we have both 'good' and 'bad' to define a range

    Raise Abort exception otherwise."""
    if state['good'] and state['bad']:
        return True
    if not state['good']:
        raise error.Abort(_('cannot bisect (no known good revisions)'))
    else:
        raise error.Abort(_('cannot bisect (no known bad revisions)'))

def get(repo, status):
    """
    Return a list of revision(s) that match the given status:

    - ``good``, ``bad``, ``skip``: csets explicitly marked as good/bad/skip
    - ``goods``, ``bads``      : csets topologically good/bad
    - ``range``              : csets taking part in the bisection
    - ``pruned``             : csets that are goods, bads or skipped
    - ``untested``           : csets whose fate is yet unknown
    - ``ignored``            : csets ignored due to DAG topology
    - ``current``            : the cset currently being bisected
    """
    state = load_state(repo)
    if status in ('good', 'bad', 'skip', 'current'):
        return map(repo.changelog.rev, state[status])
    else:
        # In the following sets, we do *not* call 'bisect()' with more
        # than one level of recursion, because that can be very, very
        # time consuming. Instead, we always develop the expression as
        # much as possible.

        # 'range' is all csets that make the bisection:
        #   - have a good ancestor and a bad descendant, or conversely
        # that's because the bisection can go either way
        range = '( bisect(bad)::bisect(good) | bisect(good)::bisect(bad) )'

        _t = repo.revs('bisect(good)::bisect(bad)')
        # The sets of topologically good or bad csets
        if len(_t) == 0:
            # Goods are topologically after bads
            goods = 'bisect(good)::'    # Pruned good csets
            bads  = '::bisect(bad)'     # Pruned bad csets
        else:
            # Goods are topologically before bads
            goods = '::bisect(good)'    # Pruned good csets
            bads  = 'bisect(bad)::'     # Pruned bad csets

        # 'pruned' is all csets whose fate is already known: good, bad, skip
        skips = 'bisect(skip)'                 # Pruned skipped csets
        pruned = '( (%s) | (%s) | (%s) )' % (goods, bads, skips)

        # 'untested' is all cset that are- in 'range', but not in 'pruned'
        untested = '( (%s) - (%s) )' % (range, pruned)

        # 'ignored' is all csets that were not used during the bisection
        # due to DAG topology, but may however have had an impact.
        # E.g., a branch merged between bads and goods, but whose branch-
        # point is out-side of the range.
        iba = '::bisect(bad) - ::bisect(good)'  # Ignored bads' ancestors
        iga = '::bisect(good) - ::bisect(bad)'  # Ignored goods' ancestors
        ignored = '( ( (%s) | (%s) ) - (%s) )' % (iba, iga, range)

        if status == 'range':
            return repo.revs(range)
        elif status == 'pruned':
            return repo.revs(pruned)
        elif status == 'untested':
            return repo.revs(untested)
        elif status == 'ignored':
            return repo.revs(ignored)
        elif status == "goods":
            return repo.revs(goods)
        elif status == "bads":
            return repo.revs(bads)
        else:
            raise error.ParseError(_('invalid bisect state'))

def label(repo, node):
    rev = repo.changelog.rev(node)

    # Try explicit sets
    if rev in get(repo, 'good'):
        # i18n: bisect changeset status
        return _('good')
    if rev in get(repo, 'bad'):
        # i18n: bisect changeset status
        return _('bad')
    if rev in get(repo, 'skip'):
        # i18n: bisect changeset status
        return _('skipped')
    if rev in get(repo, 'untested') or rev in get(repo, 'current'):
        # i18n: bisect changeset status
        return _('untested')
    if rev in get(repo, 'ignored'):
        # i18n: bisect changeset status
        return _('ignored')

    # Try implicit sets
    if rev in get(repo, 'goods'):
        # i18n: bisect changeset status
        return _('good (implicit)')
    if rev in get(repo, 'bads'):
        # i18n: bisect changeset status
        return _('bad (implicit)')

    return None

def printresult(ui, repo, state, displayer, nodes, good):
    if len(nodes) == 1:
        # narrowed it down to a single revision
        if good:
            ui.write(_("The first good revision is:\n"))
        else:
            ui.write(_("The first bad revision is:\n"))
        displayer.show(repo[nodes[0]])
        extendnode = extendrange(repo, state, nodes, good)
        if extendnode is not None:
            ui.write(_('Not all ancestors of this changeset have been'
                       ' checked.\nUse bisect --extend to continue the '
                       'bisection from\nthe common ancestor, %s.\n')
                     % extendnode)
    else:
        # multiple possible revisions
        if good:
            ui.write(_("Due to skipped revisions, the first "
                    "good revision could be any of:\n"))
        else:
            ui.write(_("Due to skipped revisions, the first "
                    "bad revision could be any of:\n"))
        for n in nodes:
            displayer.show(repo[n])
    displayer.close()