~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 by 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

"""Copying of history from one branch to another.

The basic plan is that every branch knows the history of everything

that has merged into it.  As the first step of a merge, pull, or

branch operation we copy history from the source into the destination

branch.

The copying is done in a slightly complicated order.  We don't want to

add a revision to the store until everything it refers to is also

stored, so that if a revision is present we can totally recreate it.

However, we can't know what files are included in a revision until we

read its inventory.  So we query the inventory store of the source for

the ids we need, and then pull those ids and finally actually join

the inventories.

"""

import bzrlib

import bzrlib.errors as errors

from bzrlib.errors import (InstallFailed,

                           )

from bzrlib.trace import mutter

from bzrlib.progress import ProgressPhase

from bzrlib.revision import NULL_REVISION

from bzrlib.symbol_versioning import (deprecated_function,

        deprecated_method,

        zero_eight,

        )

# TODO: Avoid repeatedly opening weaves so many times.

# XXX: This doesn't handle ghost (not present in branch) revisions at

# all yet.  I'm not sure they really should be supported.

# NOTE: This doesn't copy revisions which may be present but not

# merged into the last revision.  I'm not sure we want to do that.

# - get a list of revisions that need to be pulled in

# - for each one, pull in that revision file

#   and get the inventory, and store the inventory with right

#   parents.

# - and get the ancestry, and store that with right parents too

# - and keep a note of all file ids and version seen

# - then go through all files; for each one get the weave,

#   and add in all file versions

@deprecated_function(zero_eight)

def greedy_fetch(to_branch, from_branch, revision=None, pb=None):

    """Legacy API, please see branch.fetch(from_branch, last_revision, pb)."""

    f = Fetcher(to_branch, from_branch, revision, pb)

    return f.count_copied, f.failed_revisions

fetch = greedy_fetch

class RepoFetcher(object):

    """Pull revisions and texts from one repository to another.

    last_revision

        if set, try to limit to the data this revision references.

    after running:

    count_copied -- number of revisions copied

    This should not be used directory, its essential a object to encapsulate

    the logic in InterRepository.fetch().

    """

    def __init__(self, to_repository, from_repository, last_revision=None, pb=None):

        # result variables.

        self.failed_revisions = []

        self.count_copied = 0

        if to_repository.control_files._transport.base == from_repository.control_files._transport.base:

            # check that last_revision is in 'from' and then return a no-operation.

            if last_revision not in (None, NULL_REVISION):

                from_repository.get_revision(last_revision)

            return

        self.to_repository = to_repository

        self.from_repository = from_repository

        # must not mutate self._last_revision as its potentially a shared instance

        self._last_revision = last_revision

        if pb is None:

            self.pb = bzrlib.ui.ui_factory.nested_progress_bar()

            self.nested_pb = self.pb

        else:

            self.pb = pb

            self.nested_pb = None

        self.from_repository.lock_read()

        try:

            self.to_repository.lock_write()

            try:

                self.__fetch()

            finally:

                if self.nested_pb is not None:

                    self.nested_pb.finished()

                self.to_repository.unlock()

        finally:

            self.from_repository.unlock()

    def __fetch(self):

        """Primary worker function.

        This initialises all the needed variables, and then fetches the 

        requested revisions, finally clearing the progress bar.

        """

        self.to_weaves = self.to_repository.weave_store

        self.to_control = self.to_repository.control_weaves

        self.from_weaves = self.from_repository.weave_store

        self.from_control = self.from_repository.control_weaves

        self.count_total = 0

        self.file_ids_names = {}

        pp = ProgressPhase('Fetch phase', 4, self.pb)

        try:

            pp.next_phase()

            revs = self._revids_to_fetch()

            # something to do ?

            if revs:

                pp.next_phase()

                self._fetch_weave_texts(revs)

                pp.next_phase()

                self._fetch_inventory_weave(revs)

                pp.next_phase()

                self._fetch_revision_texts(revs)

                self.count_copied += len(revs)

        finally:

            self.pb.clear()

    def _revids_to_fetch(self):

        mutter('fetch up to rev {%s}', self._last_revision)

        if self._last_revision is NULL_REVISION:

            # explicit limit of no revisions needed

            return None

        if (self._last_revision is not None and

            self.to_repository.has_revision(self._last_revision)):

            return None

        try:

            return self.to_repository.missing_revision_ids(self.from_repository,

                                                           self._last_revision)

        except errors.NoSuchRevision:

            raise InstallFailed([self._last_revision])

    def _fetch_weave_texts(self, revs):

        texts_pb = bzrlib.ui.ui_factory.nested_progress_bar()

        try:

            # fileids_altered_by_revision_ids requires reading the inventory

            # weave, we will need to read the inventory weave again when

            # all this is done, so enable caching for that specific weave

            inv_w = self.from_repository.get_inventory_weave()

            inv_w.enable_cache()

            file_ids = self.from_repository.fileids_altered_by_revision_ids(revs)

            count = 0

            num_file_ids = len(file_ids)

            for file_id, required_versions in file_ids.items():

                texts_pb.update("fetch texts", count, num_file_ids)

                count +=1

                to_weave = self.to_weaves.get_weave_or_empty(file_id,

                    self.to_repository.get_transaction())

                from_weave = self.from_weaves.get_weave(file_id,

                    self.from_repository.get_transaction())

                # we fetch all the texts, because texts do

                # not reference anything, and its cheap enough

                to_weave.join(from_weave, version_ids=required_versions)

                # we don't need *all* of this data anymore, but we dont know

                # what we do. This cache clearing will result in a new read 

                # of the knit data when we do the checkout, but probably we

                # want to emit the needed data on the fly rather than at the

                # end anyhow.

                # the from weave should know not to cache data being joined,

                # but its ok to ask it to clear.

                from_weave.clear_cache()

                to_weave.clear_cache()

        finally:

            texts_pb.finished()

    def _fetch_inventory_weave(self, revs):

        pb = bzrlib.ui.ui_factory.nested_progress_bar()

        try:

            pb.update("fetch inventory", 0, 2)

            to_weave = self.to_control.get_weave('inventory',

                    self.to_repository.get_transaction())

            child_pb = bzrlib.ui.ui_factory.nested_progress_bar()

            try:

                # just merge, this is optimisable and its means we don't

                # copy unreferenced data such as not-needed inventories.

                pb.update("fetch inventory", 1, 3)

                from_weave = self.from_repository.get_inventory_weave()

                pb.update("fetch inventory", 2, 3)

                # we fetch only the referenced inventories because we do not

                # know for unselected inventories whether all their required

                # texts are present in the other repository - it could be

                # corrupt.

                to_weave.join(from_weave, pb=child_pb, msg='merge inventory',

                              version_ids=revs)

                from_weave.clear_cache()

            finally:

                child_pb.finished()

        finally:

            pb.finished()

class GenericRepoFetcher(RepoFetcher):

    """This is a generic repo to repo fetcher.

    This makes minimal assumptions about repo layout and contents.

    It triggers a reconciliation after fetching to ensure integrity.

    """

    def _fetch_revision_texts(self, revs):

        """Fetch revision object texts"""

        rev_pb = bzrlib.ui.ui_factory.nested_progress_bar()

        try:

            to_txn = self.to_transaction = self.to_repository.get_transaction()

            count = 0

            total = len(revs)

            to_store = self.to_repository._revision_store

            for rev in revs:

                pb = bzrlib.ui.ui_factory.nested_progress_bar()

                try:

                    pb.update('copying revisions', count, total)

                    try:

                        sig_text = self.from_repository.get_signature_text(rev)

                        to_store.add_revision_signature_text(rev, sig_text, to_txn)

                    except errors.NoSuchRevision:

                        # not signed.

                        pass

                    to_store.add_revision(self.from_repository.get_revision(rev),

                                          to_txn)

                    count += 1

                finally:

                    pb.finished()

            # fixup inventory if needed: 

            # this is expensive because we have no inverse index to current ghosts.

            # but on local disk its a few seconds and sftp push is already insane.

            # so we just-do-it.

            # FIXME: repository should inform if this is needed.

            self.to_repository.reconcile()

        finally:

            rev_pb.finished()

class KnitRepoFetcher(RepoFetcher):

    """This is a knit format repository specific fetcher.

    This differs from the GenericRepoFetcher by not doing a 

    reconciliation after copying, and using knit joining to

    copy revision texts.

    """

    def _fetch_revision_texts(self, revs):

        # may need to be a InterRevisionStore call here.

        from_transaction = self.from_repository.get_transaction()

        to_transaction = self.to_repository.get_transaction()

        to_sf = self.to_repository._revision_store.get_signature_file(

            to_transaction)

        from_sf = self.from_repository._revision_store.get_signature_file(

            from_transaction)

        to_sf.join(from_sf, version_ids=revs, ignore_missing=True)

        to_rf = self.to_repository._revision_store.get_revision_file(

            to_transaction)

        from_rf = self.from_repository._revision_store.get_revision_file(

            from_transaction)

        to_rf.join(from_rf, version_ids=revs)

class Fetcher(object):

    """Backwards compatibility glue for branch.fetch()."""

    @deprecated_method(zero_eight)

    def __init__(self, to_branch, from_branch, last_revision=None, pb=None):

        """Please see branch.fetch()."""

        to_branch.fetch(from_branch, last_revision, pb)