/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 bzrlib import (

    osutils,

    )

from bzrlib.config import Config

from bzrlib.errors import (

    BzrError,

    NoSuchFile,

    UnknownFormatError,

    NoCommonAncestor,

    NoSuchId,

    UnrelatedBranches,

    )

from bzrlib.generate_ids import gen_revision_id

from bzrlib.graph import FrozenHeadsCache

from bzrlib.merge import Merger

from bzrlib.revision import NULL_REVISION

from bzrlib.trace import mutter

from bzrlib.tsort import topo_sort

import bzrlib.ui as ui

from bzrlib.plugins.rebase.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'

def rebase_plan_exists(wt):

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

    :param wt: Working tree for which to check.

    :return: boolean

    """

    try:

        return wt._transport.get_bytes(REBASE_PLAN_FILENAME) != ''

    except NoSuchFile:

        return False

def read_rebase_plan(wt):

    """Read a rebase plan file.

    :param wt: Working Tree for which to write the plan.

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

    """

    text = wt._transport.get_bytes(REBASE_PLAN_FILENAME)

    if text == '':

        raise NoSuchFile(REBASE_PLAN_FILENAME)

    return unmarshall_rebase_plan(text)

def write_rebase_plan(wt, replace_map):

    """Write a rebase plan file.

    :param wt: Working Tree for which to write the plan.

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

    """

    content = marshall_rebase_plan(wt.branch.last_revision_info(), replace_map)

    assert type(content) == str

    wt._transport.put_bytes(REBASE_PLAN_FILENAME, content)

def remove_rebase_plan(wt):

    """Remove a rebase plan file.

    :param wt: Working Tree for which to remove the plan.

    """

    wt._transport.put_bytes(REBASE_PLAN_FILENAME, '')

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

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

    for oldrev in replace_map:

        (newrev, newparents) = replace_map[oldrev]

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

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

    # Make sure header is there

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

        raise UnknownFormatError(lines[0])

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

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

    replace_map = {}

    for l in lines[2:]:

        if l == "":

            # Skip empty lines

            continue

        pts = l.split(" ")

        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."""

    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 from

        stop_revid back through the left hand ancestry 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)

    left_most_path = []

    if stop_revid is None:

        stop_revid = order[-1]

    rev = stop_revid

    while rev in parent_map:

        left_most_path.append(rev)

        if rev == start_revid:

            # manual specified early-stop

            break

        rev = parent_map[rev][0]

    left_most_path.reverse()

    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()

    new_parent = onto_revid

    todo = left_most_path

    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

        if len(oldparents) > 1:

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

            parents = [new_parent]

            for parent in parents:

                if parent in additional_parents and parent not in parents:

                    # Use as a parent

                    parent = replace_map.get(parent, (parent,))[0]

                    parents.append(parent)

            parents = tuple(parents)

            if len(parents) == 1 and skip_full_merged:

                continue

        else:

            parents = (new_parent,)

        newrevid = generate_revid(oldrevid)

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

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

        replace_map[oldrevid] = (newrevid, parents)

        new_parent = newrevid

    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 not children.has_key(r):

            children[r] = []

        if ps is None: # Ghost

            continue

        parent_map[r] = ps

        if not children.has_key(r):

            children[r] = []

        for p in ps:

            if not children.has_key(p):

                children[p] = []

            children[p].append(r)

    parent_map.update(graph.get_parent_map(filter(lambda x: not x 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 replace_map.has_key(c):

                    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))

                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 replace_map.has_key(revid):

            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, replay_fn):

    """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

            replay_fn(repository, revid, newrevid, newparents)

    finally:

        pb.finished()

def replay_snapshot(repository, oldrevid, newrevid, new_parents):

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

    parents.

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

    :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), "replay_snapshot: Expected tuple for %r" % new_parents

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

                               (newrevid, oldrevid, new_parents))

    oldrev = repository.get_revision(oldrevid)

    revprops = dict(oldrev.properties)

    revprops[REVPROP_REBASE_OF] = oldrevid

    builder = repository.get_commit_builder(branch=None, 

                                            parents=new_parents, 

                                            config=Config(),

                                            committer=oldrev.committer,

                                            timestamp=oldrev.timestamp,

                                            timezone=oldrev.timezone,

                                            revprops=revprops,

                                            revision_id=newrevid)

    try:

        # Check what new_ie.file_id should be

        # use old and new parent inventories to generate new_id map

        nonghost_oldparents = tuple([p for p in oldrev.parent_ids if repository.has_revision(p)])

        nonghost_newparents = tuple([p for p in new_parents if repository.has_revision(p)])

        fileid_map = map_file_ids(repository, nonghost_oldparents, nonghost_newparents)

        oldtree = repository.revision_tree(oldrevid)

        mappedtree = MapTree(oldtree, fileid_map)

        pb = ui.ui_factory.nested_progress_bar()

        try:

            old_parent_invs = list(repository.iter_inventories(nonghost_oldparents))

            new_parent_invs = list(repository.iter_inventories(nonghost_newparents))

            for i, (path, old_ie) in enumerate(mappedtree.inventory.iter_entries()):

                pb.update('upgrading file', i, len(mappedtree.inventory))

                ie = old_ie.copy()

                # Either this file was modified last in this revision, 

                # in which case it has to be rewritten

                if old_ie.revision == oldrevid:

                    if repository.texts.has_key((ie.file_id, newrevid)):

                        # Use the existing text

                        ie.revision = newrevid

                    else:

                        # Create a new text

                        ie.revision = None

                else:

                    # or it was already there before the commit, in 

                    # which case the right revision should be used

                    # one of the old parents had this revision, so find that

                    # and then use the matching new parent

                    old_file_id = oldtree.inventory.path2id(path)

                    assert old_file_id is not None

                    ie = None

                    for (old_pinv, new_pinv) in zip(old_parent_invs, new_parent_invs):

                        if (old_pinv.has_id(old_file_id) and

                            old_pinv[old_file_id].revision == old_ie.revision):

                            try:

                                ie = new_pinv[old_ie.file_id].copy()

                            except NoSuchId:

                                raise ReplayParentsInconsistent(old_ie.file_id, old_ie.revision)

                            break

                    assert ie is not None

                builder.record_entry_contents(ie, new_parent_invs, path, mappedtree,

                        mappedtree.path_content_summary(path))

        finally:

            pb.finished()

        builder.finish_inventory()

        return builder.commit(oldrev.message)

    except:

        builder.abort()

        raise

def commit_rebase(wt, oldrev, newrevid):

    """Commit a rebase.

    :param wt: Mutable tree with the changes.

    :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

    committer = 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 not oldrev.committer in authors:

            authors.append(oldrev.committer)

    if 'author' in revprops:

        del revprops['author']

    if 'authors' in revprops:

        del revprops['authors']

    wt.commit(message=oldrev.message, timestamp=oldrev.timestamp, 

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

              committer=committer, authors=authors)

    write_active_rebase_revid(wt, None)

def replay_determine_base(graph, oldrevid, oldparents, newrevid, newparents):

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

    :param graph: Revision graph.

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

    except NoCommonAncestor:

        return oldparents[0]

def replay_delta_workingtree(wt, oldrevid, newrevid, newparents, 

                             merge_type=None):

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

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

    :param oldrevid: Old revision id

    :param newrevid: New revision id

    :param newparents: New parent revision ids

    """

    repository = wt.branch.repository

    if merge_type is None:

        from bzrlib.merge import Merge3Merger

        merge_type = Merge3Merger

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

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

    # in the working tree

    complete_revert(wt, [newparents[0]])

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

    oldtree = repository.revision_tree(oldrevid)

    write_active_rebase_revid(wt, oldrevid)

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

    merger.set_other_revision(oldrevid, wt.branch)

    base_revid = replay_determine_base(repository.get_graph(),

                                       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, wt.branch)

    merger.merge_type = merge_type

    merger.do_merge()

    for newparent in newparents[1:]:

        wt.add_pending_merge(newparent)

    commit_rebase(wt, oldrev, newrevid)

def workingtree_replay(wt, map_ids=False, merge_type=None):

    """Returns a function that can replay revisions in wt.

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

    :param map_ids: Whether to try to map between file ids (False for path-based merge)

    """

    def replay(repository, oldrevid, newrevid, newparents):

        assert wt.branch.repository == repository, "Different repository"

        return replay_delta_workingtree(wt, oldrevid, newrevid, newparents, 

                                        merge_type=merge_type)

    return replay

def write_active_rebase_revid(wt, revid):

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

    :param wt: Working Tree that is being used for the rebase.

    :param revid: Revision id to write

    """

    if revid is None:

        revid = NULL_REVISION

    assert type(revid) == str

    wt._transport.put_bytes(REBASE_CURRENT_REVID_FILENAME, revid)

def read_active_rebase_revid(wt):

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

    :param wt: Working Tree that is being used for the rebase.

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

    """

    try:

        text = wt._transport.get_bytes(REBASE_CURRENT_REVID_FILENAME).rstrip("\n")

        if text == NULL_REVISION:

            return None

        return text

    except NoSuchFile:

        return None

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 (f, _, _) in delta.added:

        abs_path = wt.abspath(f)

        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

class ReplayParentsInconsistent(BzrError):

    """Raised when parents were inconsistent."""

    _fmt = """Parents were inconsistent while replaying commit for file id %(fileid)s, revision %(revid)s."""

    def __init__(self, fileid, revid):

        BzrError.__init__(self)

        self.fileid = fileid

        self.revid = revid