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# Copyright (C) 2004, 2005 by Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Make a copy of an entire branch and all its history.
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This is the underlying function for the branch/get/clone commands."""
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# TODO: This could be done *much* more efficiently by just copying
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# all the whole weaves and revisions, rather than getting one
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# TODO: Optionally, after copying, discard any irrelevant information from
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# the destination, such as revisions committed after the last one we're interested
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# in. This needs to apply a weave prune operation (not written yet) to each
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# Copying must be done in a way that supports http transports, where we
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# can't list a directory, and therefore have to rely on information
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# retrieved from top-level objects whose names we do know.
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# In practice this means we first fetch the revision history and ancestry.
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# These give us a list of all the revisions that need to be fetched. We
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# also get the inventory weave. We then just need to get a list of all
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# file-ids ever referenced by this tree. (It might be nice to keep a list
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# of them directly.) This is done by walking over the inventories of all
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# copied revisions and accumulating a list of file ids.
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# For local branches it is possible to optimize this considerably in two
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# ways. One is to hardlink the files (if possible and requested), rather
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# than copying them. Another is to simply list the directory rather than
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# walking through the inventories to find out what files are present -- but
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# there it may be better to just be consistent with remote branches.
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from bzrlib.merge import build_working_dir
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from bzrlib.branch import Branch
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from bzrlib.trace import mutter, note
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from bzrlib.store import copy_all
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def copy_branch(branch_from, to_location, revision=None, basis_branch=None):
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"""Copy branch_from into the existing directory to_location.
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Returns the newly created branch object.
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If not None, only revisions up to this point will be copied.
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The head of the new branch will be that revision. Must be a
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to_location -- The destination directory; must either exist and be
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empty, or not exist, in which case it is created.
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A local branch to copy revisions from, related to branch_from.
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This is used when branching from a remote (slow) branch, and we have
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a local branch that might contain some relevant revisions.
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assert isinstance(branch_from, Branch)
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assert isinstance(to_location, basestring)
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if basis_branch is not None:
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note("basis_branch is not supported for fast weave copy yet.")
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history = _get_truncated_history(branch_from, revision)
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if not os.path.exists(to_location):
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branch_to = Branch.initialize(to_location)
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mutter("copy branch from %s to %s", branch_from, branch_to)
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branch_to.set_root_id(branch_from.get_root_id())
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branch_to.append_revision(*history)
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_copy_control_weaves(branch_from, branch_to)
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_copy_text_weaves(branch_from, branch_to)
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_copy_revision_store(branch_from, branch_to)
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build_working_dir(to_location)
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branch_to.set_parent(branch_from.base)
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def _get_truncated_history(branch_from, revision):
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history = branch_from.revision_history()
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idx = history.index(revision)
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raise InvalidRevisionId('revision {%s} is not on the mainline of %s'
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% (revision, branch_from))
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return history[:idx+1]
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def _copy_text_weaves(branch_from, branch_to):
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# TODO: Handle UnlistableStore and fall back to getting a list of
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# all file-ids and copying them one by one.
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copy_all(branch_from.weave_store, branch_to.weave_store)
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def _copy_revision_store(branch_from, branch_to):
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# TODO: Copy all revisions mentioned in the ancestry of the selected revision
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copy_all(branch_from.revision_store, branch_to.revision_store)
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def _copy_control_weaves(branch_from, branch_to):
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to_control = branch_to.control_weaves
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from_control = branch_from.control_weaves
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to_control.copy_multi(from_control, ['inventory', 'ancestry'])
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def copy_branch_slower(branch_from, to_location, revision=None, basis_branch=None):
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"""Copy branch_from into the existing directory to_location.
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If not None, only revisions up to this point will be copied.
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The head of the new branch will be that revision. Must be a
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to_location -- The destination directory; must either exist and be
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empty, or not exist, in which case it is created.
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The revision to copy up to
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A local branch to copy revisions from, related to branch_from.
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This is used when branching from a remote (slow) branch, and we have
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a local branch that might contain some relevant revisions.
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assert isinstance(branch_from, Branch)
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assert isinstance(to_location, basestring)
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if not os.path.exists(to_location):
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os.mkdir(to_location)
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br_to = Branch.initialize(to_location)
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mutter("copy branch from %s to %s", branch_from, br_to)
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if basis_branch is not None:
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basis_branch.push_stores(br_to)
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br_to.set_root_id(branch_from.get_root_id())
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revision = branch_from.last_revision()
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br_to.update_revisions(branch_from, stop_revision=revision)
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build_working_dir(to_location)
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br_to.set_parent(branch_from.base)