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# 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
"""Experiment in converting existing bzr branches to weaves."""
# 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.
import os
import tempfile
import sys
import shutil
from bzrlib.branch import Branch, find_branch
from bzrlib.branch import BZR_BRANCH_FORMAT_5, BZR_BRANCH_FORMAT_6
import bzrlib.hashcache as hashcache
from bzrlib.weave import Weave
from bzrlib.weavefile import read_weave, write_weave
from bzrlib.ui import ui_factory
from bzrlib.atomicfile import AtomicFile
from bzrlib.xml4 import serializer_v4
from bzrlib.xml5 import serializer_v5
from bzrlib.trace import mutter, note, warning
from bzrlib.osutils import sha_strings, sha_string, pathjoin, abspath
class Convert(object):
def __init__(self, base_dir):
self.base = base_dir
self.converted_revs = set()
self.absent_revisions = set()
self.text_count = 0
self.revisions = {}
self.convert()
def convert(self):
if not self._open_branch():
return
note('starting upgrade of %s', os.path.abspath(self.base))
self._backup_control_dir()
self.pb = ui_factory.progress_bar()
if self.old_format == 4:
note('starting upgrade from format 4 to 5')
self.branch.lock_write()
try:
self._convert_to_weaves()
finally:
self.branch.unlock()
self._open_branch()
if self.old_format == 5:
note('starting upgrade from format 5 to 6')
self.branch.lock_write()
try:
self._convert_to_prefixed()
finally:
self.branch.unlock()
self._open_branch()
cache = hashcache.HashCache(abspath(self.base))
cache.clear()
cache.write()
note("finished")
def _convert_to_prefixed(self):
from bzrlib.store import hash_prefix
for store_name in ["weaves", "revision-store"]:
note("adding prefixes to %s" % store_name)
store_dir = pathjoin(self.base, ".bzr", store_name)
for filename in os.listdir(store_dir):
if filename.endswith(".weave") or filename.endswith(".gz"):
file_id = os.path.splitext(filename)[0]
else:
file_id = filename
prefix_dir = pathjoin(store_dir, hash_prefix(file_id))
if not os.path.isdir(prefix_dir):
os.mkdir(prefix_dir)
os.rename(pathjoin(store_dir, filename),
pathjoin(prefix_dir, filename))
self._set_new_format(BZR_BRANCH_FORMAT_6)
def _convert_to_weaves(self):
note('note: upgrade may be faster if all store files are ungzipped first')
if not os.path.isdir(self.base + '/.bzr/weaves'):
os.mkdir(self.base + '/.bzr/weaves')
self.inv_weave = Weave('inventory')
# holds in-memory weaves for all files
self.text_weaves = {}
os.remove(self.branch.control_files.controlfilename('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()
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._write_all_weaves()
self._write_all_revs()
self._cleanup_spare_files()
self._set_new_format(BZR_BRANCH_FORMAT_5)
def _open_branch(self):
self.branch = Branch.open_downlevel(self.base)
self.old_format = self.branch._branch_format
if self.old_format == 6:
note('this branch is in the most current format')
return False
if self.old_format not in (4, 5):
raise BzrError("cannot upgrade from branch format %r" %
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(self):
for n in 'merged-patches', 'pending-merged-patches':
p = self.branch.control_files.controlfilename(n)
if not os.path.exists(p):
continue
## assert os.path.getsize(p) == 0
os.remove(p)
shutil.rmtree(self.base + '/.bzr/inventory-store')
shutil.rmtree(self.base + '/.bzr/text-store')
def _backup_control_dir(self):
orig = self.base + '/.bzr'
backup = orig + '.backup'
note('making backup of tree history')
shutil.copytree(orig, backup)
note('%s has been backed up to %s', orig, backup)
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.controlfile('inventory', 'rb'))
new_inv_xml = serializer_v5.write_inventory_to_string(inv)
branch.control_files.put_utf8('inventory', new_inv_xml)
def _write_all_weaves(self):
write_a_weave(self.inv_weave, self.base + '/.bzr/inventory.weave')
i = 0
try:
for file_id, file_weave in self.text_weaves.items():
self.pb.update('writing weave', i, len(self.text_weaves))
write_a_weave(file_weave, self.base + '/.bzr/weaves/%s.weave' % file_id)
i += 1
finally:
self.pb.clear()
def _write_all_revs(self):
"""Write all revisions out in new form."""
shutil.rmtree(self.base + '/.bzr/revision-store')
os.mkdir(self.base + '/.bzr/revision-store')
try:
for i, rev_id in enumerate(self.converted_revs):
self.pb.update('write revision', i, len(self.converted_revs))
f = file(self.base + '/.bzr/revision-store/%s' % rev_id, 'wb')
try:
serializer_v5.write_revision(self.revisions[rev_id], f)
finally:
f.close()
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 write_a_weave(weave, filename):
inv_wf = file(filename, 'wb')
try:
write_weave(weave, inv_wf)
finally:
inv_wf.close()
def upgrade(base_dir):
Convert(base_dir)
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