# bisect extension for mercurial

#

# 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, incorporated herein by reference.

from mercurial.i18n import _

from mercurial import hg, util, commands, cmdutil

import os, sys

class bisect(object):

    """dichotomic search in the DAG of changesets"""

    def __init__(self, ui, repo):

        self.repo = repo

        self.path = repo.join("bisect")

        self.opener = util.opener(self.path)

        self.ui = ui

        self.good_path = "good"

        self.bad_path = "bad"

        self.is_reset = False

        if os.path.exists(os.path.join(self.path, self.good_path)):

        if os.path.exists(os.path.join(self.path, self.bad_path)):

            r = self.opener(self.bad_path).read().splitlines()

            if r:

    def write(self):

        if self.is_reset:

            return

        if not os.path.isdir(self.path):

            os.mkdir(self.path)

        f = self.opener(self.good_path, "w")

            f.write("\n")

        f = self.opener(self.bad_path, "w")

    def init(self):

        """start a new bisection"""

        if os.path.isdir(self.path):

            raise util.Abort(_("bisect directory already exists\n"))

        os.mkdir(self.path)

        return 0

    def reset(self):

        """finish a bisection"""

        if os.path.isdir(self.path):

            sl = [os.path.join(self.path, p)

                  for p in [self.bad_path, self.good_path]]

            for s in sl:

                if os.path.exists(s):

                    os.unlink(s)

            os.rmdir(self.path)

        # Not sure about this

        #self.ui.write("Going back to tip\n")

        #self.repo.update(self.repo.changelog.tip())

        self.is_reset = True

        return 0

    def candidates(self):

        """

        returns (anc, n_child) where anc is the set of the ancestors of head

        and n_child is a dictionary with the following mapping:

        node -> number of ancestors (self included)

        """

        cl = self.repo.changelog

        stop = {}

            if g in stop:

                continue

            stop.update(cl.reachable(g))

        if bad in stop:

            raise util.Abort(_("Inconsistent state, %s:%s is good and bad")

                             % (cl.rev(bad), hg.short(bad)))

        # build a dict of node -> [number of children, {}]

        n_child = {bad: [0, {}]}

        for i in xrange(cl.rev(bad)+1):

            n = cl.node(i)

            if n not in n_child:

                n_child[n] = [0, {}]

            # increment count of each parent

            for p in cl.parents(n):

                if p != hg.nullid:

                    n_child[p][0] += 1

        for i in xrange(cl.rev(bad)+1):

            n = cl.node(i)

            for p in cl.parents(n):

                if p != hg.nullid:

                    n_child[p][0] -= 1

                    if not n in stop:

                        n_child[n][1].update(n_child[p][1])

                    if n_child[p][0] == 0:

                        n_child[p] = len(n_child[p][1])

            if not n in stop:

                n_child[n][1][n] = 1

            if n_child[n][0] == 0:

                if n == bad:

                    anc = n_child[n][1]

                n_child[n] = len(n_child[n][1])

        return anc, n_child

    def next(self):

            raise util.Abort(_("You should give at least one bad revision"))

            self.ui.warn(_("No good revision given\n"))

            self.ui.warn(_("Marking the first revision as good\n"))

        ancestors, n_child = self.candidates()

        # have we narrowed it down to one entry?

        tot = len(ancestors)

        if tot == 1:

                raise util.Abort(_("Could not find the first bad revision"))

            self.ui.write(_("The first bad revision is:\n"))

            displayer = cmdutil.show_changeset(self.ui, self.repo, {})

            return None

        # find the best node to test

        best_len = -1

        for n in ancestors:

            a = n_child[n] # number of children

            b = tot - a # number of ancestors

            value = min(a, b) # how good is this test?

            if value > best_len:

                best_len = value

        # compute the approximate number of remaining tests

        nb_tests = 0

        q, r = divmod(tot, 2)

        while q:

            nb_tests += 1

            q, r = divmod(q, 2)

        msg = _("Testing changeset %s:%s (%s changesets remaining, "

        self.ui.write(msg)

    def autonext(self):

        """find and update to the next revision to test"""

            cmdutil.bail_if_changed(self.repo)

    def autogood(self, rev=None):

        """mark revision as good and update to the next revision to test"""

            return self.autonext()

    def autobad(self, rev=None):

        """mark revision as bad and update to the next revision to test"""

            self.autonext()

# should we put it in the class ?

def test(ui, repo, rev):

    """test the bisection code"""

    b = bisect(ui, repo)

    anc = b.ancestors()

    while len(anc) > 1:

            ui.warn("failure while bisecting\n")

            sys.exit(1)

        ui.write("it worked :)\n")

        ui.write("choosing if good or bad\n")

            ui.write("it is bad\n")

        else:

            ui.write("it is good\n")

        anc = b.ancestors()

    for v in anc:

            ui.warn("fail to found cset! :(\n")

            return 1

    ui.write("Everything is ok :)\n")

    return 0

def bisect_run(ui, repo, cmd=None, *args):

    """Dichotomic search in the DAG of changesets

This extension helps to find changesets which cause problems.

To use, mark the earliest changeset you know introduces the problem

as bad, then mark the latest changeset which is free from the problem

as good. Bisect will update your working directory to a revision for

testing. Once you have performed tests, mark the working directory

as bad or good and bisect will either update to another candidate

changeset or announce that it has found the bad revision.

Note: bisect expects bad revisions to be descendants of good revisions.

If you are looking for the point at which a problem was fixed, then make

the problem-free state "bad" and the problematic state "good."

For subcommands see "hg bisect help\"

    """

    def help_(cmd=None, *args):

        """show help for a given bisect subcommand or all subcommands"""

        cmdtable = bisectcmdtable

        if cmd:

            doc = cmdtable[cmd][0].__doc__

            synopsis = cmdtable[cmd][2]

            ui.write(synopsis + "\n")

            ui.write("\n" + doc + "\n")

            return

        ui.write(_("list of subcommands for the bisect extension\n\n"))

        cmds = cmdtable.keys()

        cmds.sort()

        m = max([len(c) for c in cmds])

        for cmd in cmds:

            doc = cmdtable[cmd][0].__doc__.splitlines(0)[0].rstrip()

            ui.write(" %-*s   %s\n" % (m, cmd, doc))

    b = bisect(ui, repo)

    bisectcmdtable = {

        "init": (b.init, 0, _("hg bisect init")),

        "bad": (b.autobad, 1, _("hg bisect bad [<rev>]")),

        "good": (b.autogood, 1, _("hg bisect good [<rev>]")),

        "next": (b.autonext, 0, _("hg bisect next")),

        "reset": (b.reset, 0, _("hg bisect reset")),

        "help": (help_, 1, _("hg bisect help [<subcommand>]")),

    }

    if not bisectcmdtable.has_key(cmd):

        ui.warn(_("bisect: Unknown sub-command\n"))

        return help_()

    if len(args) > bisectcmdtable[cmd][1]:

        ui.warn(_("bisect: Too many arguments\n"))

        return help_()

    ret = bisectcmdtable[cmd][0](*args)

    b.write()

    return ret

cmdtable = {

    "bisect": (bisect_run, [], _("hg bisect [help|init|reset|next|good|bad]")),

    #"bisect-test": (test, [], "hg bisect-test rev"),

}