mercurial/hbisect.py
author Gregory Szorc <gregory.szorc@gmail.com>
Sat, 08 Jul 2017 16:18:04 -0700
changeset 33373 fb320398a21c
parent 30399 e124e83fd159
child 35149 fd8b6b183073
permissions -rw-r--r--
dirstate: expose a sparse matcher on dirstate (API) The sparse extension performs a lot of monkeypatching of dirstate to make it sparse aware. Essentially, various operations need to take the active sparse config into account. They do this by obtaining a matcher representing the sparse config and filtering paths through it. The monkeypatching is done by stuffing a reference to a repo on dirstate and calling sparse.matcher() (which takes a repo instance) during each function call. The reason this function takes a repo instance is because resolving the sparse config may require resolving file contents from filelogs, and that requires a repo. (If the current sparse config references "profile" files, the contents of those files from the dirstate's parent revisions is resolved.) I seem to recall people having strong opinions that the dirstate object not have a reference to a repo. So copying what the sparse extension does probably won't fly in core. Plus, the dirstate modifications shouldn't require a full repo: they only need a matcher. So there's no good reason to stuff a reference to the repo in dirstate. This commit exposes a sparse matcher to dirstate via a property that when looked up will call a function that eventually calls sparse.matcher(). The repo instance is bound in a closure, so it isn't exposed to dirstate. This approach is functionally similar to what the sparse extension does today, except it hides the repo instance from dirstate. The approach is not optimal because we have to call a proxy function and sparse.matcher() on every property lookup. There is room to cache the matcher instance in dirstate. After all, the matcher only changes if the dirstate's parents change or if the sparse config changes. It feels like we should be able to detect both events and update the matcher when this occurs. But for now we preserve the existing semantics so we can move the dirstate sparseness bits into core. Once in core, refactoring becomes a bit easier since it will be clearer how all these components interact. The sparse extension has been updated to use the new property. Because all references to the repo on dirstate have been removed, the code for setting it has been removed.

# changelog bisection for mercurial
#
# Copyright 2007 Matt Mackall
# Copyright 2005, 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org>
#
# 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(changelog, 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.
    """

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

    def buildancestors(bad, good):
        # only the earliest bad revision matters
        badrev = min([changelog.rev(n) for n in bad])
        goodrevs = [changelog.rev(n) for n in good]
        goodrev = min(goodrevs)
        # build visit array
        ancestors = [None] * (len(changelog) + 1) # an extra for [-1]

        # set nodes descended from goodrevs
        for rev in goodrevs:
            ancestors[rev] = []
        for rev in changelog.revs(goodrev + 1):
            for prev in clparents(rev):
                if ancestors[prev] == []:
                    ancestors[rev] = []

        # clear good revs from array
        for rev in goodrevs:
            ancestors[rev] = None
        for rev in changelog.revs(len(changelog), goodrev):
            if ancestors[rev] is None:
                for prev in clparents(rev):
                    ancestors[prev] = None

        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, %s:%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 shortlabel(label):
    if label:
        return label[0].upper()

    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()