# obsolete.py - introduce the obsolete concept in mercurial.

#

# Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org>

#                Logilab SA        <contact@logilab.fr>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

"""Introduce the Obsolete concept to mercurial

General concept

===============

This extension introduces the *obsolete* concept. It adds a new *obsolete*

relation between two changesets. A relation ``<changeset B> obsolete <changeset

A>`` is set to denote that ``<changeset B>`` is new version of ``<changeset

A>``.

The *obsolete* relation act as a **perpendicular history** to the standard

changeset history. Standard changeset history versions files. The *obsolete*

relation versions changesets.

:obsolete:     a changeset that has been replaced by another one.

:unstable:     a changeset that is not obsolete but has an obsolete ancestor.

:suspended:    an obsolete changeset with unstable descendant.

:extinct:      an obsolete changeset without unstable descendant.

               (subject to garbage collection)

Another name for unstable could be out of sync.

Usage and Feature

=================

New commands

------------

Note that rebased changesets are now marked obsolete instead of being stripped.

"""

from mercurial import util

try:

    from mercurial import obsolete

    obsolete._enabled = True

except ImportError:

        raise util.Abort('Obsolete extension requires Mercurial 2.3 (or later)')

import sys

from mercurial.i18n import _

from mercurial import cmdutil

from mercurial import commands

from mercurial import context

from mercurial import discovery

from mercurial import error

from mercurial import extensions

from mercurial import localrepo

from mercurial import phases

from mercurial import revset

from mercurial import scmutil

from mercurial import templatekw

from mercurial.node import bin, short, nullid

# This extension hold the following code

#

# - Extension Helper code

# - Obsolescence cache

# - ...

# - Older format compat

#####################################################################

### Extension helper                                              ###

#####################################################################

class exthelper(object):

    """Helper for modular extension setup

    A single helper should be intanciated for each extension. Helper method are

    then used as decorator for various purpose.

    All decorator returns the original function and may be chained.

    """

    def __init__(self):

        self._uicallables = []

        self._extcallables = []

        self._repocallables = []

        self._revsetsymbols = []

        self._templatekws = []

        self._commandwrappers = []

        self._extcommandwrappers = []

        self._functionwrappers = []

        self._duckpunchers = []

    def final_uisetup(self, ui):

        """Method to be used as a the extension uisetup

        The following operations belong here:

        - Changes to ui.__class__ . The ui object that will be used to run the

          command has not yet been created. Changes made here will affect ui

          objects created after this, and in particular the ui that will be

          passed to runcommand

        - Command wraps (extensions.wrapcommand)

        - Changes that need to be visible by other extensions: because

          initialization occurs in phases (all extensions run uisetup, then all

          run extsetup), a change made here will be visible by other extensions

          during extsetup

        - Monkeypatches or function wraps (extensions.wrapfunction) of dispatch

          module members

        - Setup of pre-* and post-* hooks

        - pushkey setup

        """

        for cont, funcname, func in self._duckpunchers:

            setattr(cont, funcname, func)

        for command, wrapper in self._commandwrappers:

            extensions.wrapcommand(commands.table, command, wrapper)

        for cont, funcname, wrapper in self._functionwrappers:

            extensions.wrapfunction(cont, funcname, wrapper)

        for c in self._uicallables:

            c(ui)

    def final_extsetup(self, ui):

        """Method to be used as a the extension extsetup

        The following operations belong here:

        - Changes depending on the status of other extensions. (if extensions.find('mq'))

        - Add a global option to all commands

        - Extend revsets 

        """

        knownexts = {}

        for name, symbol in self._revsetsymbols:

            revset.symbols[name] = symbol

        for name, kw in self._templatekws:

            templatekw.keywords[name] = kw

        for ext, command, wrapper in self._extcommandwrappers:

            if ext not in knownexts:

                e = extensions.find('rebase')

                if e is None:

                    raise util.Abort('extension %s not found' %e)

                knownexts[ext] = e.cmdtable

            extensions.wrapcommand(knownexts[ext], commands, wrapper)

        for c in self._extcallables:

            c(ui)

    def final_reposetup(self, ui, repo):

        """Method to be used as a the extension reposetup

        The following operations belong here:

        - All hooks but pre-* and post-*

        - Modify configuration variables

        - Changes to repo.__class__, repo.dirstate.__class__

        """

        for c in self._repocallables:

            c(ui, repo)

    def uisetup(self, call):

        """Decorated function will be executed during uisetup

        example::

            @eh.uisetup

            def setupbabar(ui):

                print 'this is uisetup!'

        """

        self._uicallables.append(call)

        return call

    def extsetup(self, call):

        """Decorated function will be executed during extsetup

        example::

            @eh.extsetup

            def setupcelestine(ui):

                print 'this is extsetup!'

        """

        self._uicallables.append(call)

        return call

    def reposetup(self, call):

        """Decorated function will be executed during reposetup

        example::

            @eh.reposetup

            def setupzephir(ui, repo):

                print 'this is reposetup!'

        """

        self._repocallables.append(call)

        return call

    def revset(self, symbolname):

        """Decorated function is a revset symbol

        The name of the symbol must be given as the decorator argument.

        The symbol is added during `extsetup`.

        example::

            @eh.revset('hidden')

            def revsetbabar(repo, subset, x):

                args = revset.getargs(x, 0, 0, 'babar accept no argument')

                return [r for r in subset if 'babar' in repo[r].description()]

        """

        def dec(symbol):

            self._revsetsymbols.append((symbolname, symbol))

            return symbol

        return dec

    def templatekw(self, keywordname):

        """Decorated function is a revset keyword

        The name of the keyword must be given as the decorator argument.

        The symbol is added during `extsetup`.

        example::

            @eh.templatekw('babar')

            def kwbabar(ctx):

                return 'babar'

        """

        def dec(keyword):

            self._templatekws.append((keywordname, keyword))

            return keyword

        return dec

    def wrapcommand(self, command, extension=None):

        """Decorated function is a command wrapper

        The name of the command must be given as the decorator argument.

        The wrapping is installed during `uisetup`.

        If the second option `extension` argument is provided, the wrapping

        will be applied in the extension commandtable. This argument must be a

        string that will be searched using `extension.find` if not found and

        Abort error is raised. If the wrapping apply to an extension, it is

        installed during `extsetup`

        example::

            @eh.wrapcommand('summary')

            def wrapsummary(orig, ui, repo, *args, **kwargs):

                ui.note('Barry!')

                return orig(ui, repo, *args, **kwargs)

        """

        def dec(wrapper):

            if extension is None:

                self._commandwrappers.append((command, wrapper))

            else:

                self._extcommandwrappers.append((extension, command, wrapper))

            return wrapper

        return dec

    def wrapfunction(self, container, funcname):

        """Decorated function is a function wrapper

        This function take two argument, the container and the name of the

        function to wrap. The wrapping is performed during `uisetup`.

        (there is don't support extension)

        example::

            @eh.function(discovery, 'checkheads')

            def wrapfunction(orig, *args, **kwargs):

                ui.note('His head smashed in and his heart cut out')

                return orig(*args, **kwargs)

        """

        def dec(wrapper):

            self._functionwrappers.append((container, funcname, wrapper))

            return wrapper

        return dec

    def addattr(self, container, funcname):

        """Decorated function is to be added to the container

        This function take two argument, the container and the name of the

        function to wrap. The wrapping is performed during `uisetup`.

        example::

            @eh.function(context.changectx, 'babar')

            def babar(ctx):

                return 'babar' in ctx.description

        """

        def dec(func):

            self._duckpunchers.append((container, funcname, func))

            return func

        return dec

eh = exthelper()

uisetup = eh.final_uisetup

extsetup = eh.final_extsetup

reposetup = eh.final_reposetup

#####################################################################

### Obsolescence Caching Logic                                    ###

#####################################################################

# Obsolescence related logic can be very slow if we don't have efficient cache.

#

# This section implements a cache mechanism that did not make it into core for

# time reason. It store meaningful set of revision related to obsolescence

# (obsolete, unstabletble ...

#

# Here is:

#

# - Computation of meaningful set,

# - Cache access logic,

# - Cache invalidation logic,

# - revset and ctx using this cache.

#

### Computation of meaningful set

#

# Most set can be computed with "simple" revset.

#: { set name -> function to compute this set } mapping

#:   function take a single "repo" argument.

#:

#: Use the `cachefor` decorator to register new cache function

cachefuncs = {}

def cachefor(name):

    """Decorator to register a function as computing the cache for a set"""

    def decorator(func):

        assert name not in cachefuncs

        cachefuncs[name] = func

        return func

    return decorator

@cachefor('obsolete')

def _computeobsoleteset(repo):

    """the set of obsolete revision"""

    obs = set()

    nm = repo.changelog.nodemap

    for prec in repo.obsstore.precursors:

        rev = nm.get(prec)

        if rev is not None:

            obs.add(rev)

    return set(repo.revs('%ld - public()', obs))

@cachefor('unstable')

def _computeunstableset(repo):

    """the set of non obsolete revision with obsolete parent"""

    return set(repo.revs('(obsolete()::) - obsolete()'))

@cachefor('suspended')

def _computesuspendedset(repo):

    """the set of obsolete parent with non obsolete descendant"""

    return set(repo.revs('obsolete() and obsolete()::unstable()'))

@cachefor('extinct')

def _computeextinctset(repo):

    """the set of obsolete parent without non obsolete descendant"""

    return set(repo.revs('obsolete() - obsolete()::unstable()'))

@eh.wrapfunction(obsolete.obsstore, '__init__')

def _initobsstorecache(orig, obsstore, *args, **kwargs):

    """add a caches attributes to obsstore"""

    obsstore.caches = {}

    return orig(obsstore, *args, **kwargs)

### Cache access

def getobscache(repo, name):

    """Return the set of revision that belong to the <name> set

    Such access may compute the set and cache it for future use"""

    if not repo.obsstore:

        return ()

    if name not in repo.obsstore.caches:

        repo.obsstore.caches[name] = cachefuncs[name](repo)

    return repo.obsstore.caches[name]

### Cache clean up

#

# To be simple we need to invalidate obsolescence cache when:

#

# - new changeset is added:

# - public phase is changed

# - obsolescence marker are added

# - strip is used a repo

def clearobscaches(repo):

    """Remove all obsolescence related cache from a repo

    This remove all cache in obsstore is the obsstore already exist on the

    repo.

    (We could be smarter here)"""

    if 'obsstore' in repo._filecache:

        repo.obsstore.caches.clear()

@eh.wrapfunction(localrepo.localrepository, 'addchangegroup')  # new changeset

@eh.wrapfunction(phases, 'retractboundary')  # phase movement

@eh.wrapfunction(phases, 'advanceboundary')  # phase movement

@eh.wrapfunction(localrepo.localrepository, 'destroyed')  # strip

def wrapclearcache(orig, repo, *args, **kwargs):

    try:

        return orig(repo, *args, **kwargs)

    finally:

        # we are a bit wide here

        # we could restrict to:

        # advanceboundary + phase==public

        # retractboundary + phase==draft

        clearobscaches(repo)

@eh.wrapfunction(obsolete.obsstore, 'add')  # new marker

def clearonadd(orig, obsstore, *args, **kwargs):

    try: