/brz/remove-bazaar

# Copyright (C) 2006-2007 by Jelmer Vernooij

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Rebase."""

import os

from ... import (

    config as _mod_config,

    osutils,

    )

from ...errors import (

    BzrError,

    NoSuchFile,

    UnknownFormatError,

    NoCommonAncestor,

    UnrelatedBranches,

    )

from ...bzr.generate_ids import gen_revision_id

from ...graph import FrozenHeadsCache

from ...merge import Merger

from ...revision import NULL_REVISION

from ...trace import mutter

from ...tsort import topo_sort

from ...tree import TreeChange

from ... import ui

from .maptree import (

    MapTree,

    map_file_ids,

    )

REBASE_PLAN_FILENAME = 'rebase-plan'

REBASE_CURRENT_REVID_FILENAME = 'rebase-current'

REBASE_PLAN_VERSION = 1

REVPROP_REBASE_OF = 'rebase-of'

class RebaseState(object):

    def has_plan(self):

        """Check whether there is a rebase plan present.

        :return: boolean

        """

        raise NotImplementedError(self.has_plan)

    def read_plan(self):

        """Read a rebase plan file.

        :return: Tuple with last revision info and replace map.

        """

        raise NotImplementedError(self.read_plan)

    def write_plan(self, replace_map):

        """Write a rebase plan file.

        :param replace_map: Replace map (old revid -> (new revid, new parents))

        """

        raise NotImplementedError(self.write_plan)

    def remove_plan(self):

        """Remove a rebase plan file.

        """

        raise NotImplementedError(self.remove_plan)

    def write_active_revid(self, revid):

        """Write the id of the revision that is currently being rebased.

        :param revid: Revision id to write

        """

        raise NotImplementedError(self.write_active_revid)

    def read_active_revid(self):

        """Read the id of the revision that is currently being rebased.

        :return: Id of the revision that is being rebased.

        """

        raise NotImplementedError(self.read_active_revid)

class RebaseState1(RebaseState):

    def __init__(self, wt):

        self.wt = wt

        self.transport = wt._transport

    def has_plan(self):

        """See `RebaseState`."""

        try:

            return self.transport.get_bytes(REBASE_PLAN_FILENAME) != b''

        except NoSuchFile:

            return False

    def read_plan(self):

        """See `RebaseState`."""

        text = self.transport.get_bytes(REBASE_PLAN_FILENAME)

        if text == b'':

            raise NoSuchFile(REBASE_PLAN_FILENAME)

        return unmarshall_rebase_plan(text)

    def write_plan(self, replace_map):

        """See `RebaseState`."""

        self.wt.update_feature_flags({b"rebase-v1": b"write-required"})

        content = marshall_rebase_plan(

            self.wt.branch.last_revision_info(), replace_map)

        assert isinstance(content, bytes)

        self.transport.put_bytes(REBASE_PLAN_FILENAME, content)

    def remove_plan(self):

        """See `RebaseState`."""

        self.wt.update_feature_flags({b"rebase-v1": None})

        self.transport.put_bytes(REBASE_PLAN_FILENAME, b'')

    def write_active_revid(self, revid):

        """See `RebaseState`."""

        if revid is None:

            revid = NULL_REVISION

        assert isinstance(revid, bytes)

        self.transport.put_bytes(REBASE_CURRENT_REVID_FILENAME, revid)

    def read_active_revid(self):

        """See `RebaseState`."""

        try:

            text = self.transport.get_bytes(REBASE_CURRENT_REVID_FILENAME).rstrip(b"\n")

            if text == NULL_REVISION:

                return None

            return text

        except NoSuchFile:

            return None

def marshall_rebase_plan(last_rev_info, replace_map):

    """Marshall a rebase plan.

    :param last_rev_info: Last revision info tuple.

    :param replace_map: Replace map (old revid -> (new revid, new parents))

    :return: string

    """

    ret = b"# Bazaar rebase plan %d\n" % REBASE_PLAN_VERSION

    ret += b"%d %s\n" % last_rev_info

    for oldrev in replace_map:

        (newrev, newparents) = replace_map[oldrev]

        ret += b"%s %s" % (oldrev, newrev) + \

            b"".join([b" %s" % p for p in newparents]) + b"\n"

    return ret

def unmarshall_rebase_plan(text):

    """Unmarshall a rebase plan.

    :param text: Text to parse

    :return: Tuple with last revision info, replace map.

    """

    lines = text.split(b'\n')

    # Make sure header is there

    if lines[0] != b"# Bazaar rebase plan %d" % REBASE_PLAN_VERSION:

        raise UnknownFormatError(lines[0])

    pts = lines[1].split(b" ", 1)

    last_revision_info = (int(pts[0]), pts[1])

    replace_map = {}

    for l in lines[2:]:

        if l == b"":

            # Skip empty lines

            continue

        pts = l.split(b" ")

        replace_map[pts[0]] = (pts[1], tuple(pts[2:]))

    return (last_revision_info, replace_map)

def regenerate_default_revid(repository, revid):

    """Generate a revision id for the rebase of an existing revision.

    :param repository: Repository in which the revision is present.

    :param revid: Revision id of the revision that is being rebased.

    :return: new revision id."""

    if revid == NULL_REVISION:

        return NULL_REVISION

    rev = repository.get_revision(revid)

    return gen_revision_id(rev.committer, rev.timestamp)

def generate_simple_plan(todo_set, start_revid, stop_revid, onto_revid, graph,

                         generate_revid, skip_full_merged=False):

    """Create a simple rebase plan that replays history based

    on one revision being replayed on top of another.

    :param todo_set: A set of revisions to rebase. Only the revisions

        topologically between stop_revid and start_revid (inclusive) are

        rebased; other revisions are ignored (and references to them are

        preserved).

    :param start_revid: Id of revision at which to start replaying

    :param stop_revid: Id of revision until which to stop replaying

    :param onto_revid: Id of revision on top of which to replay

    :param graph: Graph object

    :param generate_revid: Function for generating new revision ids

    :param skip_full_merged: Skip revisions that merge already merged

                             revisions.

    :return: replace map

    """

    assert start_revid is None or start_revid in todo_set, \

        "invalid start revid(%r), todo_set(%r)" % (start_revid, todo_set)

    assert stop_revid is None or stop_revid in todo_set, "invalid stop_revid"

    replace_map = {}

    parent_map = graph.get_parent_map(todo_set)

    order = topo_sort(parent_map)

    if stop_revid is None:

        stop_revid = order[-1]

    if start_revid is None:

        # We need a common base.

        lca = graph.find_lca(stop_revid, onto_revid)

        if lca == set([NULL_REVISION]):

            raise UnrelatedBranches()

        start_revid = order[0]

    todo = order[order.index(start_revid):order.index(stop_revid) + 1]

    heads_cache = FrozenHeadsCache(graph)

    # XXX: The output replacemap'd parents should get looked up in some manner

    # by the heads cache? RBC 20080719

    for oldrevid in todo:

        oldparents = parent_map[oldrevid]

        assert isinstance(oldparents, tuple), "not tuple: %r" % oldparents

        parents = []

        # Left parent:

        if heads_cache.heads((oldparents[0], onto_revid)) == set((onto_revid,)):

            parents.append(onto_revid)

        elif oldparents[0] in replace_map:

            parents.append(replace_map[oldparents[0]][0])

        else:

            parents.append(onto_revid)

            parents.append(oldparents[0])

        # Other parents:

        if len(oldparents) > 1:

            additional_parents = heads_cache.heads(oldparents[1:])

            for oldparent in oldparents[1:]:

                if oldparent in additional_parents:

                    if heads_cache.heads((oldparent, onto_revid)) == set((onto_revid,)):

                        pass

                    elif oldparent in replace_map:

                        newparent = replace_map[oldparent][0]

                        if parents[0] == onto_revid:

                            parents[0] = newparent

                        else:

                            parents.append(newparent)

                    else:

                        parents.append(oldparent)

            if len(parents) == 1 and skip_full_merged:

                continue

        parents = tuple(parents)

        newrevid = generate_revid(oldrevid, parents)

        assert newrevid != oldrevid, "old and newrevid equal (%r)" % newrevid

        assert isinstance(parents, tuple), "parents not tuple: %r" % parents

        replace_map[oldrevid] = (newrevid, parents)

    return replace_map

def generate_transpose_plan(ancestry, renames, graph, generate_revid):

    """Create a rebase plan that replaces a bunch of revisions

    in a revision graph.

    :param ancestry: Ancestry to consider

    :param renames: Renames of revision

    :param graph: Graph object

    :param generate_revid: Function for creating new revision ids

    """

    replace_map = {}

    todo = []

    children = {}

    parent_map = {}

    for r, ps in ancestry:

        if r not in children:

            children[r] = []

        if ps is None: # Ghost

            continue

        parent_map[r] = ps

        if r not in children:

            children[r] = []

        for p in ps:

            if p not in children:

                children[p] = []

            children[p].append(r)

    parent_map.update(graph.get_parent_map(filter(lambda x: x not in parent_map, renames.values())))

    # todo contains a list of revisions that need to

    # be rewritten

    for r, v in renames.items():

        replace_map[r] = (v, parent_map[v])

        todo.append(r)

    total = len(todo)

    processed = set()

    i = 0

    pb = ui.ui_factory.nested_progress_bar()

    try:

        while len(todo) > 0:

            r = todo.pop()

            processed.add(r)

            i += 1

            pb.update('determining dependencies', i, total)

            # Add entry for them in replace_map

            for c in children[r]:

                if c in renames:

                    continue

                if c in replace_map:

                    parents = replace_map[c][1]

                else:

                    parents = parent_map[c]

                assert isinstance(parents, tuple), \

                    "Expected tuple of parents, got: %r" % parents

                # replace r in parents with replace_map[r][0]

                if not replace_map[r][0] in parents:

                    parents = list(parents)

                    parents[parents.index(r)] = replace_map[r][0]

                    parents = tuple(parents)

                replace_map[c] = (generate_revid(c, tuple(parents)),

                                  tuple(parents))

                if replace_map[c][0] == c:

                    del replace_map[c]

                elif c not in processed:

                    todo.append(c)

    finally:

        pb.finished()

    # Remove items from the map that already exist

    for revid in renames:

        if revid in replace_map:

            del replace_map[revid]

    return replace_map

def rebase_todo(repository, replace_map):

    """Figure out what revisions still need to be rebased.

    :param repository: Repository that contains the revisions

    :param replace_map: Replace map

    """

    for revid, parent_ids in replace_map.items():

        assert isinstance(parent_ids, tuple), "replace map parents not tuple"

        if not repository.has_revision(parent_ids[0]):

            yield revid

def rebase(repository, replace_map, revision_rewriter):

    """Rebase a working tree according to the specified map.

    :param repository: Repository that contains the revisions

    :param replace_map: Dictionary with revisions to (optionally) rewrite

    :param merge_fn: Function for replaying a revision

    """

    # Figure out the dependencies

    graph = repository.get_graph()

    todo = list(graph.iter_topo_order(replace_map.keys()))

    pb = ui.ui_factory.nested_progress_bar()

    try:

        for i, revid in enumerate(todo):

            pb.update('rebase revisions', i, len(todo))

            (newrevid, newparents) = replace_map[revid]

            assert isinstance(newparents, tuple), "Expected tuple for %r" % newparents

            if repository.has_revision(newrevid):

                # Was already converted, no need to worry about it again

                continue

            revision_rewriter(revid, newrevid, newparents)

    finally:

        pb.finished()

def wrap_iter_changes(old_iter_changes, map_tree):

    for change in old_iter_changes:

        if change.parent_id[0] is not None:

            old_parent = map_tree.new_id(change.parent_id[0])

        else:

            old_parent = change.parent_id[0]

        if change.parent_id[1] is not None:

            new_parent = map_tree.new_id(change.parent_id[1])

        else:

            new_parent = change.parent_id[1]

        yield TreeChange(

            map_tree.new_id(change.file_id), change.path,

            change.changed_content, change.versioned,

            (old_parent, new_parent), change.name, change.kind,

            change.executable)

class CommitBuilderRevisionRewriter(object):

    """Revision rewriter that use commit builder.

    :ivar repository: Repository in which the revision is present.

    """

    def __init__(self, repository, map_ids=True):

        self.repository = repository

        self.map_ids = map_ids

    def _get_present_revisions(self, revids):

        return tuple([p for p in revids if self.repository.has_revision(p)])

    def __call__(self, oldrevid, newrevid, new_parents):

        """Replay a commit by simply commiting the same snapshot with different

        parents.

        :param oldrevid: Revision id of the revision to copy.

        :param newrevid: Revision id of the revision to create.

        :param new_parents: Revision ids of the new parent revisions.

        """

        assert isinstance(new_parents, tuple), "CommitBuilderRevisionRewriter: Expected tuple for %r" % new_parents

        mutter('creating copy %r of %r with new parents %r',

               newrevid, oldrevid, new_parents)

        oldrev = self.repository.get_revision(oldrevid)

        revprops = dict(oldrev.properties)

        revprops[REVPROP_REBASE_OF] = oldrevid.decode('utf-8')

        # Check what new_ie.file_id should be

        # use old and new parent trees to generate new_id map

        nonghost_oldparents = self._get_present_revisions(oldrev.parent_ids)

        nonghost_newparents = self._get_present_revisions(new_parents)

        oldtree = self.repository.revision_tree(oldrevid)

        if self.map_ids:

            fileid_map = map_file_ids(

                self.repository, nonghost_oldparents,

                nonghost_newparents)

            mappedtree = MapTree(oldtree, fileid_map)

        else:

            mappedtree = oldtree

        try:

            old_base = nonghost_oldparents[0]

        except IndexError:

            old_base = NULL_REVISION

        try:

            new_base = new_parents[0]

        except IndexError:

            new_base = NULL_REVISION

        old_base_tree = self.repository.revision_tree(old_base)

        old_iter_changes = oldtree.iter_changes(old_base_tree)

        iter_changes = wrap_iter_changes(old_iter_changes, mappedtree)

        builder = self.repository.get_commit_builder(

            branch=None, parents=new_parents, committer=oldrev.committer,

            timestamp=oldrev.timestamp, timezone=oldrev.timezone,

            revprops=revprops, revision_id=newrevid,

            config_stack=_mod_config.GlobalStack())

        try:

            for (relpath, fs_hash) in builder.record_iter_changes(

                    mappedtree, new_base, iter_changes):

                pass

            builder.finish_inventory()

            return builder.commit(oldrev.message)

        except:

            builder.abort()

            raise

class WorkingTreeRevisionRewriter(object):

    def __init__(self, wt, state, merge_type=None):

        """

        :param wt: Working tree in which to do the replays.

        """

        self.wt = wt

        self.graph = self.wt.branch.repository.get_graph()

        self.state = state

        self.merge_type = merge_type

    def __call__(self, oldrevid, newrevid, newparents):

        """Replay a commit in a working tree, with a different base.

        :param oldrevid: Old revision id

        :param newrevid: New revision id

        :param newparents: New parent revision ids

        """

        repository = self.wt.branch.repository

        if self.merge_type is None:

            from ...merge import Merge3Merger

            merge_type = Merge3Merger

        else:

            merge_type = self.merge_type

        oldrev = self.wt.branch.repository.get_revision(oldrevid)

        # Make sure there are no conflicts or pending merges/changes

        # in the working tree

        complete_revert(self.wt, [newparents[0]])

        assert not self.wt.changes_from(self.wt.basis_tree()).has_changed(), "Changes in rev"

        oldtree = repository.revision_tree(oldrevid)

        self.state.write_active_revid(oldrevid)

        merger = Merger(self.wt.branch, this_tree=self.wt)

        merger.set_other_revision(oldrevid, self.wt.branch)

        base_revid = self.determine_base(

            oldrevid, oldrev.parent_ids, newrevid, newparents)

        mutter('replaying %r as %r with base %r and new parents %r' %

               (oldrevid, newrevid, base_revid, newparents))

        merger.set_base_revision(base_revid, self.wt.branch)

        merger.merge_type = merge_type

        merger.do_merge()

        for newparent in newparents[1:]:

            self.wt.add_pending_merge(newparent)

        self.commit_rebase(oldrev, newrevid)

        self.state.write_active_revid(None)

    def determine_base(self, oldrevid, oldparents, newrevid, newparents):

        """Determine the base for replaying a revision using merge.

        :param oldrevid: Revid of old revision.

        :param oldparents: List of old parents revids.

        :param newrevid: Revid of new revision.

        :param newparents: List of new parents revids.

        :return: Revision id of the new new revision.

        """

        # If this was the first commit, no base is needed

        if len(oldparents) == 0:

            return NULL_REVISION

        # In the case of a "simple" revision with just one parent,

        # that parent should be the base

        if len(oldparents) == 1:

            return oldparents[0]

        # In case the rhs parent(s) of the origin revision has already been

        # merged in the new branch, use diff between rhs parent and diff from

        # original revision

        if len(newparents) == 1:

            # FIXME: Find oldparents entry that matches newparents[0]

            # and return it

            return oldparents[1]

        try:

            return self.graph.find_unique_lca(*[oldparents[0], newparents[1]])

        except NoCommonAncestor:

            return oldparents[0]

    def commit_rebase(self, oldrev, newrevid):

        """Commit a rebase.

        :param oldrev: Revision info of new revision to commit.

        :param newrevid: New revision id."""

        assert oldrev.revision_id != newrevid, "Invalid revid %r" % newrevid

        revprops = dict(oldrev.properties)

        revprops[REVPROP_REBASE_OF] = oldrev.revision_id.decode('utf-8')

        committer = self.wt.branch.get_config().username()

        authors = oldrev.get_apparent_authors()

        if oldrev.committer == committer:

            # No need to explicitly record the authors if the original

            # committer is rebasing.

            if [oldrev.committer] == authors:

                authors = None

        else:

            if oldrev.committer not in authors:

                authors.append(oldrev.committer)

        if 'author' in revprops:

            del revprops['author']

        if 'authors' in revprops:

            del revprops['authors']

        self.wt.commit(

            message=oldrev.message, timestamp=oldrev.timestamp,

            timezone=oldrev.timezone, revprops=revprops, rev_id=newrevid,

            committer=committer, authors=authors)

def complete_revert(wt, newparents):

    """Simple helper that reverts to specified new parents and makes sure none

    of the extra files are left around.

    :param wt: Working tree to use for rebase

    :param newparents: New parents of the working tree

    """

    newtree = wt.branch.repository.revision_tree(newparents[0])

    delta = wt.changes_from(newtree)

    wt.branch.generate_revision_history(newparents[0])

    wt.set_parent_ids([r for r in newparents[:1] if r != NULL_REVISION])

    for change in delta.added:

        abs_path = wt.abspath(change.path[1])

        if osutils.lexists(abs_path):

            if osutils.isdir(abs_path):

                osutils.rmtree(abs_path)

            else:

                os.unlink(abs_path)

    wt.revert(None, old_tree=newtree, backups=False)

    assert not wt.changes_from(wt.basis_tree()).has_changed(), "Rev changed"

    wt.set_parent_ids([r for r in newparents if r != NULL_REVISION])

class ReplaySnapshotError(BzrError):

    """Raised when replaying a snapshot failed."""

    _fmt = """Replaying the snapshot failed: %(msg)s."""

    def __init__(self, msg):

        BzrError.__init__(self)

        self.msg = msg