/brz/remove-bazaar

# Copyright (C) 2005 Canonical Ltd

#

# 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

"""bzr upgrade logic."""

# change upgrade from .bzr to create a '.bzr-new', then do a bait and switch.

# To make this properly useful

#

# 1. assign text version ids, and put those text versions into

#    the inventory as they're converted.

#

# 2. keep track of the previous version of each file, rather than

#    just using the last one imported

#

# 3. assign entry versions when files are added, renamed or moved.

#

# 4. when merged-in versions are observed, walk down through them

#    to discover everything, then commit bottom-up

#

# 5. track ancestry as things are merged in, and commit that in each

#    revision

#

# Perhaps it's best to first walk the whole graph and make a plan for

# what should be imported in what order?  Need a kind of topological

# sort of all revisions.  (Or do we, can we just before doing a revision

# see that all its parents have either been converted or abandoned?)

# Cannot import a revision until all its parents have been

# imported.  in other words, we can only import revisions whose

# parents have all been imported.  the first step must be to

# import a revision with no parents, of which there must be at

# least one.  (So perhaps it's useful to store forward pointers

# from a list of parents to their children?)

#

# Another (equivalent?) approach is to build up the ordered

# ancestry list for the last revision, and walk through that.  We

# are going to need that.

#

# We don't want to have to recurse all the way back down the list.

#

# Suppose we keep a queue of the revisions able to be processed at

# any point.  This starts out with all the revisions having no

# parents.

#

# This seems like a generally useful algorithm...

#

# The current algorithm is dumb (O(n**2)?) but will do the job, and

# takes less than a second on the bzr.dev branch.

# This currently does a kind of lazy conversion of file texts, where a

# new text is written in every version.  That's unnecessary but for

# the moment saves us having to worry about when files need new

# versions.

from cStringIO import StringIO

import os

import tempfile

import sys

from stat import *

import bzrlib

from bzrlib.branch import Branch

import bzrlib.bzrdir as bzrdir

from bzrlib.bzrdir import BzrDirFormat, BzrDirFormat4, BzrDirFormat5, BzrDirFormat6

import bzrlib.errors as errors

from bzrlib.errors import NoSuchFile, UpgradeReadonly

import bzrlib.hashcache as hashcache

from bzrlib.lockable_files import LockableFiles

from bzrlib.osutils import sha_strings, sha_string, pathjoin, abspath

from bzrlib.ui import ui_factory

from bzrlib.store.text import TextStore

from bzrlib.store.weave import WeaveStore

from bzrlib.trace import mutter, note, warning

from bzrlib.transactions import PassThroughTransaction

from bzrlib.transport import get_transport

from bzrlib.transport.local import LocalTransport

from bzrlib.weave import Weave

from bzrlib.weavefile import read_weave, write_weave

from bzrlib.xml4 import serializer_v4

from bzrlib.xml5 import serializer_v5

class Convert(object):

    def __init__(self, transport):

        self.base = transport.base

        self.converted_revs = set()

        self.absent_revisions = set()

        self.text_count = 0

        self.revisions = {}

        self.transport = transport

        if self.transport.is_readonly():

            raise UpgradeReadonly

        self.control_files = LockableFiles(transport.clone(bzrlib.BZRDIR), 'branch-lock')

        # Lock the branch (soon to be meta dir) to prevent anyone racing with us

        # This is currently windows incompatible, it will deadlock. When the upgrade

        # logic becomes format specific, then we can have the format know how to pass this

        # on. Also note that we probably have an 'upgrade meta' which upgrades the constituent

        # parts.

        # FIXME: control files reuse

        self.control_files.lock_write()

        try:

            self.convert()

        finally:

            self.control_files.unlock()

    def convert(self):

        if not self._open_branch():

            return

        note('starting upgrade of %s', self.base)

        self._backup_control_dir()

        self.pb = ui_factory.progress_bar()

        if isinstance(self.old_format, BzrDirFormat4):

            note('starting upgrade from format 4 to 5')

            if isinstance(self.transport, LocalTransport):

                self.bzrdir.get_workingtree_transport(None).delete('stat-cache')

            self._convert_to_weaves()

        if isinstance(self.old_format, BzrDirFormat5):

            note('starting upgrade from format 5 to 6')

            self._convert_to_prefixed()

        note("finished")

    def _convert_to_prefixed(self):

        from bzrlib.store import hash_prefix

        bzr_transport = self.transport.clone('.bzr')

        bzr_transport.delete('branch-format')

        for store_name in ["weaves", "revision-store"]:

            note("adding prefixes to %s" % store_name) 

            store_transport = bzr_transport.clone(store_name)

            for filename in store_transport.list_dir('.'):

                if (filename.endswith(".weave") or

                    filename.endswith(".gz") or

                    filename.endswith(".sig")):

                    file_id = os.path.splitext(filename)[0]

                else:

                    file_id = filename

                prefix_dir = hash_prefix(file_id)

                # FIXME keep track of the dirs made RBC 20060121

                try:

                    store_transport.move(filename, prefix_dir + '/' + filename)

                except NoSuchFile: # catches missing dirs strangely enough

                    store_transport.mkdir(prefix_dir)

                    store_transport.move(filename, prefix_dir + '/' + filename)

        self.old_format = BzrDirFormat6()

        self._set_new_format(self.old_format.get_format_string())

        self.bzrdir = self.old_format.open(self.transport)

        self.branch = self.bzrdir.open_branch()

    def _convert_to_weaves(self):

        note('note: upgrade may be faster if all store files are ungzipped first')

        bzr_transport = self.transport.clone('.bzr')

        try:

            # TODO permissions

            stat = bzr_transport.stat('weaves')

            if not S_ISDIR(stat.st_mode):

                bzr_transport.delete('weaves')

                bzr_transport.mkdir('weaves')

        except NoSuchFile:

            bzr_transport.mkdir('weaves')

        self.inv_weave = Weave('inventory')

        # holds in-memory weaves for all files

        self.text_weaves = {}

        bzr_transport.delete('branch-format')

        self._convert_working_inv()

        rev_history = self.branch.revision_history()

        # to_read is a stack holding the revisions we still need to process;

        # appending to it adds new highest-priority revisions

        self.known_revisions = set(rev_history)

        self.to_read = rev_history[-1:]

        while self.to_read:

            rev_id = self.to_read.pop()

            if (rev_id not in self.revisions

                and rev_id not in self.absent_revisions):

                self._load_one_rev(rev_id)

        self.pb.clear()

        to_import = self._make_order()

        for i, rev_id in enumerate(to_import):

            self.pb.update('converting revision', i, len(to_import))

            self._convert_one_rev(rev_id)

        self.pb.clear()

        self._write_all_weaves()

        self._write_all_revs()

        note('upgraded to weaves:')

        note('  %6d revisions and inventories' % len(self.revisions))

        note('  %6d revisions not present' % len(self.absent_revisions))

        note('  %6d texts' % self.text_count)

        self._cleanup_spare_files_after_format4()

        self.old_format = BzrDirFormat5()

        self._set_new_format(self.old_format.get_format_string())

        self.bzrdir = self.old_format.open(self.transport)

        self.branch = self.bzrdir.open_branch()

    def _open_branch(self):

        self.old_format = BzrDirFormat.find_format(self.transport)

        self.bzrdir = self.old_format.open(self.transport)

        self.branch = self.bzrdir.open_branch()

        if isinstance(self.old_format, BzrDirFormat6):

            note('this branch is in the most current format (%s)', self.old_format)

            return False

        if (not isinstance(self.old_format, BzrDirFormat4) and

            not isinstance(self.old_format, BzrDirFormat5) and

            not isinstance(self.old_format, bzrdir.BzrDirMetaFormat1)):

            raise errors.BzrError("cannot upgrade from branch format %s" %

                           self.branch._branch_format)

        return True

    def _set_new_format(self, format):

        self.branch.control_files.put_utf8('branch-format', format)

    def _cleanup_spare_files_after_format4(self):

        transport = self.transport.clone('.bzr')

        # FIXME working tree upgrade foo.

        for n in 'merged-patches', 'pending-merged-patches':

            try:

                ## assert os.path.getsize(p) == 0

                transport.delete(n)

            except NoSuchFile:

                pass

        transport.delete_tree('inventory-store')

        transport.delete_tree('text-store')

    def _backup_control_dir(self):

        note('making backup of tree history')

        self.transport.copy_tree('.bzr', '.bzr.backup')

        note('%s.bzr has been backed up to %s.bzr.backup',

             self.transport.base,

             self.transport.base)

        note('if conversion fails, you can move this directory back to .bzr')

        note('if it succeeds, you can remove this directory if you wish')

    def _convert_working_inv(self):

        branch = self.branch

        inv = serializer_v4.read_inventory(branch.control_files.get('inventory'))

        new_inv_xml = serializer_v5.write_inventory_to_string(inv)

        # FIXME inventory is a working tree change.

        branch.control_files.put('inventory', new_inv_xml)

    def _write_all_weaves(self):

        bzr_transport = self.transport.clone('.bzr')

        controlweaves = WeaveStore(bzr_transport, prefixed=False)

        weave_transport = bzr_transport.clone('weaves')

        weaves = WeaveStore(weave_transport, prefixed=False)

        transaction = PassThroughTransaction()

        controlweaves.put_weave('inventory', self.inv_weave, transaction)

        i = 0

        try:

            for file_id, file_weave in self.text_weaves.items():

                self.pb.update('writing weave', i, len(self.text_weaves))

                weaves.put_weave(file_id, file_weave, transaction)

                i += 1

        finally:

            self.pb.clear()

    def _write_all_revs(self):

        """Write all revisions out in new form."""

        transport = self.transport.clone('.bzr')

        transport.delete_tree('revision-store')

        transport.mkdir('revision-store')

        revision_transport = transport.clone('revision-store')

        # TODO permissions

        revision_store = TextStore(revision_transport,

                                   prefixed=False,

                                   compressed=True)

        try:

            for i, rev_id in enumerate(self.converted_revs):

                self.pb.update('write revision', i, len(self.converted_revs))

                rev_tmp = StringIO()

                serializer_v5.write_revision(self.revisions[rev_id], rev_tmp)

                rev_tmp.seek(0)

                revision_store.add(rev_tmp, rev_id)

        finally:

            self.pb.clear()

    def _load_one_rev(self, rev_id):

        """Load a revision object into memory.

        Any parents not either loaded or abandoned get queued to be

        loaded."""

        self.pb.update('loading revision',

                       len(self.revisions),

                       len(self.known_revisions))

        if not self.branch.repository.revision_store.has_id(rev_id):

            self.pb.clear()

            note('revision {%s} not present in branch; '

                 'will be converted as a ghost',

                 rev_id)

            self.absent_revisions.add(rev_id)

        else:

            rev_xml = self.branch.repository.revision_store.get(rev_id).read()

            rev = serializer_v4.read_revision_from_string(rev_xml)

            for parent_id in rev.parent_ids:

                self.known_revisions.add(parent_id)

                self.to_read.append(parent_id)

            self.revisions[rev_id] = rev

    def _load_old_inventory(self, rev_id):

        assert rev_id not in self.converted_revs

        old_inv_xml = self.branch.repository.inventory_store.get(rev_id).read()

        inv = serializer_v4.read_inventory_from_string(old_inv_xml)

        rev = self.revisions[rev_id]

        if rev.inventory_sha1:

            assert rev.inventory_sha1 == sha_string(old_inv_xml), \

                'inventory sha mismatch for {%s}' % rev_id

        return inv

    def _load_updated_inventory(self, rev_id):

        assert rev_id in self.converted_revs

        inv_xml = self.inv_weave.get_text(rev_id)

        inv = serializer_v5.read_inventory_from_string(inv_xml)

        return inv

    def _convert_one_rev(self, rev_id):

        """Convert revision and all referenced objects to new format."""

        rev = self.revisions[rev_id]

        inv = self._load_old_inventory(rev_id)

        present_parents = [p for p in rev.parent_ids

                           if p not in self.absent_revisions]

        self._convert_revision_contents(rev, inv, present_parents)

        self._store_new_weave(rev, inv, present_parents)

        self.converted_revs.add(rev_id)

    def _store_new_weave(self, rev, inv, present_parents):

        # the XML is now updated with text versions

        if __debug__:

            for file_id in inv:

                ie = inv[file_id]

                if ie.kind == 'root_directory':

                    continue

                assert hasattr(ie, 'revision'), \

                    'no revision on {%s} in {%s}' % \

                    (file_id, rev.revision_id)

        new_inv_xml = serializer_v5.write_inventory_to_string(inv)

        new_inv_sha1 = sha_string(new_inv_xml)

        self.inv_weave.add(rev.revision_id, 

                           present_parents,

                           new_inv_xml.splitlines(True),

                           new_inv_sha1)

        rev.inventory_sha1 = new_inv_sha1

    def _convert_revision_contents(self, rev, inv, present_parents):

        """Convert all the files within a revision.

        Also upgrade the inventory to refer to the text revision ids."""

        rev_id = rev.revision_id

        mutter('converting texts of revision {%s}',

               rev_id)

        parent_invs = map(self._load_updated_inventory, present_parents)

        for file_id in inv:

            ie = inv[file_id]

            self._convert_file_version(rev, ie, parent_invs)

    def _convert_file_version(self, rev, ie, parent_invs):

        """Convert one version of one file.

        The file needs to be added into the weave if it is a merge

        of >=2 parents or if it's changed from its parent.

        """

        if ie.kind == 'root_directory':

            return

        file_id = ie.file_id

        rev_id = rev.revision_id

        w = self.text_weaves.get(file_id)

        if w is None:

            w = Weave(file_id)

            self.text_weaves[file_id] = w

        text_changed = False

        previous_entries = ie.find_previous_heads(parent_invs, w)

        for old_revision in previous_entries:

                # if this fails, its a ghost ?

                assert old_revision in self.converted_revs 

        self.snapshot_ie(previous_entries, ie, w, rev_id)

        del ie.text_id

        assert getattr(ie, 'revision', None) is not None

    def snapshot_ie(self, previous_revisions, ie, w, rev_id):

        # TODO: convert this logic, which is ~= snapshot to

        # a call to:. This needs the path figured out. rather than a work_tree

        # a v4 revision_tree can be given, or something that looks enough like

        # one to give the file content to the entry if it needs it.

        # and we need something that looks like a weave store for snapshot to 

        # save against.

        #ie.snapshot(rev, PATH, previous_revisions, REVISION_TREE, InMemoryWeaveStore(self.text_weaves))

        if len(previous_revisions) == 1:

            previous_ie = previous_revisions.values()[0]

            if ie._unchanged(previous_ie):

                ie.revision = previous_ie.revision

                return

        parent_indexes = map(w.lookup, previous_revisions)

        if ie.has_text():

            text = self.branch.repository.text_store.get(ie.text_id)

            file_lines = text.readlines()

            assert sha_strings(file_lines) == ie.text_sha1

            assert sum(map(len, file_lines)) == ie.text_size

            w.add(rev_id, parent_indexes, file_lines, ie.text_sha1)

            self.text_count += 1

        else:

            w.add(rev_id, parent_indexes, [], None)

        ie.revision = rev_id

        ##mutter('import text {%s} of {%s}',

        ##       ie.text_id, file_id)

    def _make_order(self):

        """Return a suitable order for importing revisions.

        The order must be such that an revision is imported after all

        its (present) parents.

        """

        todo = set(self.revisions.keys())

        done = self.absent_revisions.copy()

        o = []

        while todo:

            # scan through looking for a revision whose parents

            # are all done

            for rev_id in sorted(list(todo)):

                rev = self.revisions[rev_id]

                parent_ids = set(rev.parent_ids)

                if parent_ids.issubset(done):

                    # can take this one now

                    o.append(rev_id)

                    todo.remove(rev_id)

                    done.add(rev_id)

        return o

def upgrade(url):

    t = get_transport(url)

    Convert(t)