1# Copyright (C) 2010, 2011, 2012 Canonical Ltd
2#
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 2 of the License, or
6# (at your option) any later version.
7#
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11# GNU General Public License for more details.
12#
13# You should have received a copy of the GNU General Public License
14# along with this program; if not, write to the Free Software
15# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16
17"""ControlDir is the basic control directory class.
18
19The ControlDir class is the base for the control directory used
20by all bzr and foreign formats. For the ".bzr" implementation,
21see breezy.bzrdir.BzrDir.
22
23"""
24
25from .lazy_import import lazy_import
26lazy_import(globals(), """
27import textwrap
28
29from breezy import (
30    branch as _mod_branch,
31    hooks,
32    revision as _mod_revision,
33    transport as _mod_transport,
34    trace,
35    ui,
36    urlutils,
37    )
38from breezy.transport import local
39from breezy.push import (
40    PushResult,
41    )
42
43from breezy.i18n import gettext
44""")
45
46from . import (
47    errors,
48    registry,
49    )
50
51
52class MustHaveWorkingTree(errors.BzrError):
53
54    _fmt = "Branching '%(url)s'(%(format)s) must create a working tree."
55
56    def __init__(self, format, url):
57        errors.BzrError.__init__(self, format=format, url=url)
58
59
60class BranchReferenceLoop(errors.BzrError):
61
62    _fmt = "Can not create branch reference that points at branch itself."
63
64    def __init__(self, branch):
65        errors.BzrError.__init__(self, branch=branch)
66
67
68class ControlComponent(object):
69    """Abstract base class for control directory components.
70
71    This provides interfaces that are common across controldirs,
72    repositories, branches, and workingtree control directories.
73
74    They all expose two urls and transports: the *user* URL is the
75    one that stops above the control directory (eg .bzr) and that
76    should normally be used in messages, and the *control* URL is
77    under that in eg .bzr/checkout and is used to read the control
78    files.
79
80    This can be used as a mixin and is intended to fit with
81    foreign formats.
82    """
83
84    @property
85    def control_transport(self):
86        raise NotImplementedError
87
88    @property
89    def control_url(self):
90        return self.control_transport.base
91
92    @property
93    def user_transport(self):
94        raise NotImplementedError
95
96    @property
97    def user_url(self):
98        return self.user_transport.base
99
100
101class ControlDir(ControlComponent):
102    """A control directory.
103
104    While this represents a generic control directory, there are a few
105    features that are present in this interface that are currently only
106    supported by one of its implementations, BzrDir.
107
108    These features (bound branches, stacked branches) are currently only
109    supported by Bazaar, but could be supported by other version control
110    systems as well. Implementations are required to raise the appropriate
111    exceptions when an operation is requested that is not supported.
112
113    This also makes life easier for API users who can rely on the
114    implementation always allowing a particular feature to be requested but
115    raising an exception when it is not supported, rather than requiring the
116    API users to check for magic attributes to see what features are supported.
117    """
118
119    def can_convert_format(self):
120        """Return true if this controldir is one whose format we can convert
121        from."""
122        return True
123
124    def list_branches(self):
125        """Return a sequence of all branches local to this control directory.
126
127        """
128        return list(self.get_branches().values())
129
130    def branch_names(self):
131        """List all branch names in this control directory.
132
133        :return: List of branch names
134        """
135        try:
136            self.get_branch_reference()
137        except (errors.NotBranchError, errors.NoRepositoryPresent):
138            return []
139        else:
140            return [""]
141
142    def get_branches(self):
143        """Get all branches in this control directory, as a dictionary.
144
145        :return: Dictionary mapping branch names to instances.
146        """
147        try:
148            return {"": self.open_branch()}
149        except (errors.NotBranchError, errors.NoRepositoryPresent):
150            return {}
151
152    def is_control_filename(self, filename):
153        """True if filename is the name of a path which is reserved for
154        controldirs.
155
156        :param filename: A filename within the root transport of this
157            controldir.
158
159        This is true IF and ONLY IF the filename is part of the namespace reserved
160        for bzr control dirs. Currently this is the '.bzr' directory in the root
161        of the root_transport. it is expected that plugins will need to extend
162        this in the future - for instance to make bzr talk with svn working
163        trees.
164        """
165        return self._format.is_control_filename(filename)
166
167    def needs_format_conversion(self, format=None):
168        """Return true if this controldir needs convert_format run on it.
169
170        For instance, if the repository format is out of date but the
171        branch and working tree are not, this should return True.
172
173        :param format: Optional parameter indicating a specific desired
174                       format we plan to arrive at.
175        """
176        raise NotImplementedError(self.needs_format_conversion)
177
178    def create_repository(self, shared=False):
179        """Create a new repository in this control directory.
180
181        :param shared: If a shared repository should be created
182        :return: The newly created repository
183        """
184        raise NotImplementedError(self.create_repository)
185
186    def destroy_repository(self):
187        """Destroy the repository in this ControlDir."""
188        raise NotImplementedError(self.destroy_repository)
189
190    def create_branch(self, name=None, repository=None,
191                      append_revisions_only=None):
192        """Create a branch in this ControlDir.
193
194        :param name: Name of the colocated branch to create, None for
195            the user selected branch or "" for the active branch.
196        :param append_revisions_only: Whether this branch should only allow
197            appending new revisions to its history.
198
199        The controldirs format will control what branch format is created.
200        For more control see BranchFormatXX.create(a_controldir).
201        """
202        raise NotImplementedError(self.create_branch)
203
204    def destroy_branch(self, name=None):
205        """Destroy a branch in this ControlDir.
206
207        :param name: Name of the branch to destroy, None for the
208            user selected branch or "" for the active branch.
209        :raise NotBranchError: When the branch does not exist
210        """
211        raise NotImplementedError(self.destroy_branch)
212
213    def create_workingtree(self, revision_id=None, from_branch=None,
214                           accelerator_tree=None, hardlink=False):
215        """Create a working tree at this ControlDir.
216
217        :param revision_id: create it as of this revision id.
218        :param from_branch: override controldir branch
219            (for lightweight checkouts)
220        :param accelerator_tree: A tree which can be used for retrieving file
221            contents more quickly than the revision tree, i.e. a workingtree.
222            The revision tree will be used for cases where accelerator_tree's
223            content is different.
224        """
225        raise NotImplementedError(self.create_workingtree)
226
227    def destroy_workingtree(self):
228        """Destroy the working tree at this ControlDir.
229
230        Formats that do not support this may raise UnsupportedOperation.
231        """
232        raise NotImplementedError(self.destroy_workingtree)
233
234    def destroy_workingtree_metadata(self):
235        """Destroy the control files for the working tree at this ControlDir.
236
237        The contents of working tree files are not affected.
238        Formats that do not support this may raise UnsupportedOperation.
239        """
240        raise NotImplementedError(self.destroy_workingtree_metadata)
241
242    def find_branch_format(self, name=None):
243        """Find the branch 'format' for this controldir.
244
245        This might be a synthetic object for e.g. RemoteBranch and SVN.
246        """
247        raise NotImplementedError(self.find_branch_format)
248
249    def get_branch_reference(self, name=None):
250        """Return the referenced URL for the branch in this controldir.
251
252        :param name: Optional colocated branch name
253        :raises NotBranchError: If there is no Branch.
254        :raises NoColocatedBranchSupport: If a branch name was specified
255            but colocated branches are not supported.
256        :return: The URL the branch in this controldir references if it is a
257            reference branch, or None for regular branches.
258        """
259        if name is not None:
260            raise errors.NoColocatedBranchSupport(self)
261        return None
262
263    def set_branch_reference(self, target_branch, name=None):
264        """Set the referenced URL for the branch in this controldir.
265
266        :param name: Optional colocated branch name
267        :param target_branch: Branch to reference
268        :raises NoColocatedBranchSupport: If a branch name was specified
269            but colocated branches are not supported.
270        :return: The referencing branch
271        """
272        raise NotImplementedError(self.set_branch_reference)
273
274    def open_branch(self, name=None, unsupported=False,
275                    ignore_fallbacks=False, possible_transports=None):
276        """Open the branch object at this ControlDir if one is present.
277
278        :param unsupported: if True, then no longer supported branch formats can
279            still be opened.
280        :param ignore_fallbacks: Whether to open fallback repositories
281        :param possible_transports: Transports to use for opening e.g.
282            fallback repositories.
283        """
284        raise NotImplementedError(self.open_branch)
285
286    def open_repository(self, _unsupported=False):
287        """Open the repository object at this ControlDir if one is present.
288
289        This will not follow the Branch object pointer - it's strictly a direct
290        open facility. Most client code should use open_branch().repository to
291        get at a repository.
292
293        :param _unsupported: a private parameter, not part of the api.
294        """
295        raise NotImplementedError(self.open_repository)
296
297    def find_repository(self):
298        """Find the repository that should be used.
299
300        This does not require a branch as we use it to find the repo for
301        new branches as well as to hook existing branches up to their
302        repository.
303        """
304        raise NotImplementedError(self.find_repository)
305
306    def open_workingtree(self, unsupported=False,
307                         recommend_upgrade=True, from_branch=None):
308        """Open the workingtree object at this ControlDir if one is present.
309
310        :param recommend_upgrade: Optional keyword parameter, when True (the
311            default), emit through the ui module a recommendation that the user
312            upgrade the working tree when the workingtree being opened is old
313            (but still fully supported).
314        :param from_branch: override controldir branch (for lightweight
315            checkouts)
316        """
317        raise NotImplementedError(self.open_workingtree)
318
319    def has_branch(self, name=None):
320        """Tell if this controldir contains a branch.
321
322        Note: if you're going to open the branch, you should just go ahead
323        and try, and not ask permission first.  (This method just opens the
324        branch and discards it, and that's somewhat expensive.)
325        """
326        try:
327            self.open_branch(name, ignore_fallbacks=True)
328            return True
329        except errors.NotBranchError:
330            return False
331
332    def _get_selected_branch(self):
333        """Return the name of the branch selected by the user.
334
335        :return: Name of the branch selected by the user, or "".
336        """
337        branch = self.root_transport.get_segment_parameters().get("branch")
338        if branch is None:
339            branch = ""
340        return urlutils.unescape(branch)
341
342    def has_workingtree(self):
343        """Tell if this controldir contains a working tree.
344
345        This will still raise an exception if the controldir has a workingtree
346        that is remote & inaccessible.
347
348        Note: if you're going to open the working tree, you should just go ahead
349        and try, and not ask permission first.  (This method just opens the
350        workingtree and discards it, and that's somewhat expensive.)
351        """
352        try:
353            self.open_workingtree(recommend_upgrade=False)
354            return True
355        except errors.NoWorkingTree:
356            return False
357
358    def cloning_metadir(self, require_stacking=False):
359        """Produce a metadir suitable for cloning or sprouting with.
360
361        These operations may produce workingtrees (yes, even though they're
362        "cloning" something that doesn't have a tree), so a viable workingtree
363        format must be selected.
364
365        :require_stacking: If True, non-stackable formats will be upgraded
366            to similar stackable formats.
367        :returns: a ControlDirFormat with all component formats either set
368            appropriately or set to None if that component should not be
369            created.
370        """
371        raise NotImplementedError(self.cloning_metadir)
372
373    def checkout_metadir(self):
374        """Produce a metadir suitable for checkouts of this controldir.
375
376        :returns: A ControlDirFormat with all component formats
377            either set appropriately or set to None if that component
378            should not be created.
379        """
380        return self.cloning_metadir()
381
382    def sprout(self, url, revision_id=None, force_new_repo=False,
383               recurse='down', possible_transports=None,
384               accelerator_tree=None, hardlink=False, stacked=False,
385               source_branch=None, create_tree_if_local=True,
386               lossy=False):
387        """Create a copy of this controldir prepared for use as a new line of
388        development.
389
390        If url's last component does not exist, it will be created.
391
392        Attributes related to the identity of the source branch like
393        branch nickname will be cleaned, a working tree is created
394        whether one existed before or not; and a local branch is always
395        created.
396
397        :param revision_id: if revision_id is not None, then the clone
398            operation may tune itself to download less data.
399        :param accelerator_tree: A tree which can be used for retrieving file
400            contents more quickly than the revision tree, i.e. a workingtree.
401            The revision tree will be used for cases where accelerator_tree's
402            content is different.
403        :param hardlink: If true, hard-link files from accelerator_tree,
404            where possible.
405        :param stacked: If true, create a stacked branch referring to the
406            location of this control directory.
407        :param create_tree_if_local: If true, a working-tree will be created
408            when working locally.
409        """
410        raise NotImplementedError(self.sprout)
411
412    def push_branch(self, source, revision_id=None, overwrite=False,
413                    remember=False, create_prefix=False, lossy=False,
414                    tag_selector=None):
415        """Push the source branch into this ControlDir."""
416        br_to = None
417        # If we can open a branch, use its direct repository, otherwise see
418        # if there is a repository without a branch.
419        try:
420            br_to = self.open_branch()
421        except errors.NotBranchError:
422            # Didn't find a branch, can we find a repository?
423            repository_to = self.find_repository()
424        else:
425            # Found a branch, so we must have found a repository
426            repository_to = br_to.repository
427
428        push_result = PushResult()
429        push_result.source_branch = source
430        if br_to is None:
431            # We have a repository but no branch, copy the revisions, and then
432            # create a branch.
433            if revision_id is None:
434                # No revision supplied by the user, default to the branch
435                # revision
436                revision_id = source.last_revision()
437            repository_to.fetch(source.repository, revision_id=revision_id)
438            br_to = source.sprout(
439                self, revision_id=revision_id, lossy=lossy,
440                tag_selector=tag_selector)
441            if source.get_push_location() is None or remember:
442                # FIXME: Should be done only if we succeed ? -- vila 2012-01-18
443                source.set_push_location(br_to.base)
444            push_result.stacked_on = None
445            push_result.branch_push_result = None
446            push_result.old_revno = None
447            push_result.old_revid = _mod_revision.NULL_REVISION
448            push_result.target_branch = br_to
449            push_result.master_branch = None
450            push_result.workingtree_updated = False
451        else:
452            # We have successfully opened the branch, remember if necessary:
453            if source.get_push_location() is None or remember:
454                # FIXME: Should be done only if we succeed ? -- vila 2012-01-18
455                source.set_push_location(br_to.base)
456            try:
457                tree_to = self.open_workingtree()
458            except errors.NotLocalUrl:
459                push_result.branch_push_result = source.push(
460                    br_to, overwrite, stop_revision=revision_id, lossy=lossy,
461                    tag_selector=tag_selector)
462                push_result.workingtree_updated = False
463            except errors.NoWorkingTree:
464                push_result.branch_push_result = source.push(
465                    br_to, overwrite, stop_revision=revision_id, lossy=lossy,
466                    tag_selector=tag_selector)
467                push_result.workingtree_updated = None  # Not applicable
468            else:
469                with tree_to.lock_write():
470                    push_result.branch_push_result = source.push(
471                        tree_to.branch, overwrite, stop_revision=revision_id,
472                        lossy=lossy, tag_selector=tag_selector)
473                    tree_to.update()
474                push_result.workingtree_updated = True
475            push_result.old_revno = push_result.branch_push_result.old_revno
476            push_result.old_revid = push_result.branch_push_result.old_revid
477            push_result.target_branch = \
478                push_result.branch_push_result.target_branch
479        return push_result
480
481    def _get_tree_branch(self, name=None):
482        """Return the branch and tree, if any, for this controldir.
483
484        :param name: Name of colocated branch to open.
485
486        Return None for tree if not present or inaccessible.
487        Raise NotBranchError if no branch is present.
488        :return: (tree, branch)
489        """
490        try:
491            tree = self.open_workingtree()
492        except (errors.NoWorkingTree, errors.NotLocalUrl):
493            tree = None
494            branch = self.open_branch(name=name)
495        else:
496            if name is not None:
497                branch = self.open_branch(name=name)
498            else:
499                branch = tree.branch
500        return tree, branch
501
502    def get_config(self):
503        """Get configuration for this ControlDir."""
504        raise NotImplementedError(self.get_config)
505
506    def check_conversion_target(self, target_format):
507        """Check that a controldir as a whole can be converted to a new format."""
508        raise NotImplementedError(self.check_conversion_target)
509
510    def clone(self, url, revision_id=None, force_new_repo=False,
511              preserve_stacking=False, tag_selector=None):
512        """Clone this controldir and its contents to url verbatim.
513
514        :param url: The url create the clone at.  If url's last component does
515            not exist, it will be created.
516        :param revision_id: The tip revision-id to use for any branch or
517            working tree.  If not None, then the clone operation may tune
518            itself to download less data.
519        :param force_new_repo: Do not use a shared repository for the target
520                               even if one is available.
521        :param preserve_stacking: When cloning a stacked branch, stack the
522            new branch on top of the other branch's stacked-on branch.
523        """
524        return self.clone_on_transport(_mod_transport.get_transport(url),
525                                       revision_id=revision_id,
526                                       force_new_repo=force_new_repo,
527                                       preserve_stacking=preserve_stacking,
528                                       tag_selector=tag_selector)
529
530    def clone_on_transport(self, transport, revision_id=None,
531                           force_new_repo=False, preserve_stacking=False, stacked_on=None,
532                           create_prefix=False, use_existing_dir=True, no_tree=False,
533                           tag_selector=None):
534        """Clone this controldir and its contents to transport verbatim.
535
536        :param transport: The transport for the location to produce the clone
537            at.  If the target directory does not exist, it will be created.
538        :param revision_id: The tip revision-id to use for any branch or
539            working tree.  If not None, then the clone operation may tune
540            itself to download less data.
541        :param force_new_repo: Do not use a shared repository for the target,
542                               even if one is available.
543        :param preserve_stacking: When cloning a stacked branch, stack the
544            new branch on top of the other branch's stacked-on branch.
545        :param create_prefix: Create any missing directories leading up to
546            to_transport.
547        :param use_existing_dir: Use an existing directory if one exists.
548        :param no_tree: If set to true prevents creation of a working tree.
549        """
550        raise NotImplementedError(self.clone_on_transport)
551
552    @classmethod
553    def find_controldirs(klass, transport, evaluate=None, list_current=None):
554        """Find control dirs recursively from current location.
555
556        This is intended primarily as a building block for more sophisticated
557        functionality, like finding trees under a directory, or finding
558        branches that use a given repository.
559
560        :param evaluate: An optional callable that yields recurse, value,
561            where recurse controls whether this controldir is recursed into
562            and value is the value to yield.  By default, all bzrdirs
563            are recursed into, and the return value is the controldir.
564        :param list_current: if supplied, use this function to list the current
565            directory, instead of Transport.list_dir
566        :return: a generator of found bzrdirs, or whatever evaluate returns.
567        """
568        if list_current is None:
569            def list_current(transport):
570                return transport.list_dir('')
571        if evaluate is None:
572            def evaluate(controldir):
573                return True, controldir
574
575        pending = [transport]
576        while len(pending) > 0:
577            current_transport = pending.pop()
578            recurse = True
579            try:
580                controldir = klass.open_from_transport(current_transport)
581            except (errors.NotBranchError, errors.PermissionDenied,
582                    errors.UnknownFormatError):
583                pass
584            else:
585                recurse, value = evaluate(controldir)
586                yield value
587            try:
588                subdirs = list_current(current_transport)
589            except (errors.NoSuchFile, errors.PermissionDenied):
590                continue
591            if recurse:
592                for subdir in sorted(subdirs, reverse=True):
593                    pending.append(current_transport.clone(subdir))
594
595    @classmethod
596    def find_branches(klass, transport):
597        """Find all branches under a transport.
598
599        This will find all branches below the transport, including branches
600        inside other branches.  Where possible, it will use
601        Repository.find_branches.
602
603        To list all the branches that use a particular Repository, see
604        Repository.find_branches
605        """
606        def evaluate(controldir):
607            try:
608                repository = controldir.open_repository()
609            except errors.NoRepositoryPresent:
610                pass
611            else:
612                return False, ([], repository)
613            return True, (controldir.list_branches(), None)
614        ret = []
615        for branches, repo in klass.find_controldirs(
616                transport, evaluate=evaluate):
617            if repo is not None:
618                ret.extend(repo.find_branches())
619            if branches is not None:
620                ret.extend(branches)
621        return ret
622
623    @classmethod
624    def create_branch_and_repo(klass, base, force_new_repo=False, format=None):
625        """Create a new ControlDir, Branch and Repository at the url 'base'.
626
627        This will use the current default ControlDirFormat unless one is
628        specified, and use whatever
629        repository format that that uses via controldir.create_branch and
630        create_repository. If a shared repository is available that is used
631        preferentially.
632
633        The created Branch object is returned.
634
635        :param base: The URL to create the branch at.
636        :param force_new_repo: If True a new repository is always created.
637        :param format: If supplied, the format of branch to create.  If not
638            supplied, the default is used.
639        """
640        controldir = klass.create(base, format)
641        controldir._find_or_create_repository(force_new_repo)
642        return controldir.create_branch()
643
644    @classmethod
645    def create_branch_convenience(klass, base, force_new_repo=False,
646                                  force_new_tree=None, format=None,
647                                  possible_transports=None):
648        """Create a new ControlDir, Branch and Repository at the url 'base'.
649
650        This is a convenience function - it will use an existing repository
651        if possible, can be told explicitly whether to create a working tree or
652        not.
653
654        This will use the current default ControlDirFormat unless one is
655        specified, and use whatever
656        repository format that that uses via ControlDir.create_branch and
657        create_repository. If a shared repository is available that is used
658        preferentially. Whatever repository is used, its tree creation policy
659        is followed.
660
661        The created Branch object is returned.
662        If a working tree cannot be made due to base not being a file:// url,
663        no error is raised unless force_new_tree is True, in which case no
664        data is created on disk and NotLocalUrl is raised.
665
666        :param base: The URL to create the branch at.
667        :param force_new_repo: If True a new repository is always created.
668        :param force_new_tree: If True or False force creation of a tree or
669                               prevent such creation respectively.
670        :param format: Override for the controldir format to create.
671        :param possible_transports: An optional reusable transports list.
672        """
673        if force_new_tree:
674            # check for non local urls
675            t = _mod_transport.get_transport(base, possible_transports)
676            if not isinstance(t, local.LocalTransport):
677                raise errors.NotLocalUrl(base)
678        controldir = klass.create(base, format, possible_transports)
679        repo = controldir._find_or_create_repository(force_new_repo)
680        result = controldir.create_branch()
681        if force_new_tree or (repo.make_working_trees() and
682                              force_new_tree is None):
683            try:
684                controldir.create_workingtree()
685            except errors.NotLocalUrl:
686                pass
687        return result
688
689    @classmethod
690    def create_standalone_workingtree(klass, base, format=None):
691        """Create a new ControlDir, WorkingTree, Branch and Repository at 'base'.
692
693        'base' must be a local path or a file:// url.
694
695        This will use the current default ControlDirFormat unless one is
696        specified, and use whatever
697        repository format that that uses for bzrdirformat.create_workingtree,
698        create_branch and create_repository.
699
700        :param format: Override for the controldir format to create.
701        :return: The WorkingTree object.
702        """
703        t = _mod_transport.get_transport(base)
704        if not isinstance(t, local.LocalTransport):
705            raise errors.NotLocalUrl(base)
706        controldir = klass.create_branch_and_repo(base,
707                                                  force_new_repo=True,
708                                                  format=format).controldir
709        return controldir.create_workingtree()
710
711    @classmethod
712    def open_unsupported(klass, base):
713        """Open a branch which is not supported."""
714        return klass.open(base, _unsupported=True)
715
716    @classmethod
717    def open(klass, base, possible_transports=None, probers=None,
718             _unsupported=False):
719        """Open an existing controldir, rooted at 'base' (url).
720
721        :param _unsupported: a private parameter to the ControlDir class.
722        """
723        t = _mod_transport.get_transport(base, possible_transports)
724        return klass.open_from_transport(t, probers=probers,
725                                         _unsupported=_unsupported)
726
727    @classmethod
728    def open_from_transport(klass, transport, _unsupported=False,
729                            probers=None):
730        """Open a controldir within a particular directory.
731
732        :param transport: Transport containing the controldir.
733        :param _unsupported: private.
734        """
735        for hook in klass.hooks['pre_open']:
736            hook(transport)
737        # Keep initial base since 'transport' may be modified while following
738        # the redirections.
739        base = transport.base
740
741        def find_format(transport):
742            return transport, ControlDirFormat.find_format(transport,
743                                                           probers=probers)
744
745        def redirected(transport, e, redirection_notice):
746            redirected_transport = transport._redirected_to(e.source, e.target)
747            if redirected_transport is None:
748                raise errors.NotBranchError(base)
749            trace.note(gettext('{0} is{1} redirected to {2}').format(
750                transport.base, e.permanently, redirected_transport.base))
751            return redirected_transport
752
753        try:
754            transport, format = _mod_transport.do_catching_redirections(
755                find_format, transport, redirected)
756        except errors.TooManyRedirections:
757            raise errors.NotBranchError(base)
758
759        format.check_support_status(_unsupported)
760        return format.open(transport, _found=True)
761
762    @classmethod
763    def open_containing(klass, url, possible_transports=None):
764        """Open an existing branch which contains url.
765
766        :param url: url to search from.
767
768        See open_containing_from_transport for more detail.
769        """
770        transport = _mod_transport.get_transport(url, possible_transports)
771        return klass.open_containing_from_transport(transport)
772
773    @classmethod
774    def open_containing_from_transport(klass, a_transport):
775        """Open an existing branch which contains a_transport.base.
776
777        This probes for a branch at a_transport, and searches upwards from there.
778
779        Basically we keep looking up until we find the control directory or
780        run into the root.  If there isn't one, raises NotBranchError.
781        If there is one and it is either an unrecognised format or an unsupported
782        format, UnknownFormatError or UnsupportedFormatError are raised.
783        If there is one, it is returned, along with the unused portion of url.
784
785        :return: The ControlDir that contains the path, and a Unicode path
786                for the rest of the URL.
787        """
788        # this gets the normalised url back. I.e. '.' -> the full path.
789        url = a_transport.base
790        while True:
791            try:
792                result = klass.open_from_transport(a_transport)
793                return result, urlutils.unescape(a_transport.relpath(url))
794            except errors.NotBranchError:
795                pass
796            except errors.PermissionDenied:
797                pass
798            try:
799                new_t = a_transport.clone('..')
800            except urlutils.InvalidURLJoin:
801                # reached the root, whatever that may be
802                raise errors.NotBranchError(path=url)
803            if new_t.base == a_transport.base:
804                # reached the root, whatever that may be
805                raise errors.NotBranchError(path=url)
806            a_transport = new_t
807
808    @classmethod
809    def open_tree_or_branch(klass, location, name=None):
810        """Return the branch and working tree at a location.
811
812        If there is no tree at the location, tree will be None.
813        If there is no branch at the location, an exception will be
814        raised
815        :return: (tree, branch)
816        """
817        controldir = klass.open(location)
818        return controldir._get_tree_branch(name=name)
819
820    @classmethod
821    def open_containing_tree_or_branch(klass, location,
822                                       possible_transports=None):
823        """Return the branch and working tree contained by a location.
824
825        Returns (tree, branch, relpath).
826        If there is no tree at containing the location, tree will be None.
827        If there is no branch containing the location, an exception will be
828        raised
829        relpath is the portion of the path that is contained by the branch.
830        """
831        controldir, relpath = klass.open_containing(location,
832                                                    possible_transports=possible_transports)
833        tree, branch = controldir._get_tree_branch()
834        return tree, branch, relpath
835
836    @classmethod
837    def open_containing_tree_branch_or_repository(klass, location):
838        """Return the working tree, branch and repo contained by a location.
839
840        Returns (tree, branch, repository, relpath).
841        If there is no tree containing the location, tree will be None.
842        If there is no branch containing the location, branch will be None.
843        If there is no repository containing the location, repository will be
844        None.
845        relpath is the portion of the path that is contained by the innermost
846        ControlDir.
847
848        If no tree, branch or repository is found, a NotBranchError is raised.
849        """
850        controldir, relpath = klass.open_containing(location)
851        try:
852            tree, branch = controldir._get_tree_branch()
853        except errors.NotBranchError:
854            try:
855                repo = controldir.find_repository()
856                return None, None, repo, relpath
857            except (errors.NoRepositoryPresent):
858                raise errors.NotBranchError(location)
859        return tree, branch, branch.repository, relpath
860
861    @classmethod
862    def create(klass, base, format=None, possible_transports=None):
863        """Create a new ControlDir at the url 'base'.
864
865        :param format: If supplied, the format of branch to create.  If not
866            supplied, the default is used.
867        :param possible_transports: If supplied, a list of transports that
868            can be reused to share a remote connection.
869        """
870        if klass is not ControlDir:
871            raise AssertionError("ControlDir.create always creates the"
872                                 "default format, not one of %r" % klass)
873        t = _mod_transport.get_transport(base, possible_transports)
874        t.ensure_base()
875        if format is None:
876            format = ControlDirFormat.get_default_format()
877        return format.initialize_on_transport(t)
878
879
880class ControlDirHooks(hooks.Hooks):
881    """Hooks for ControlDir operations."""
882
883    def __init__(self):
884        """Create the default hooks."""
885        hooks.Hooks.__init__(self, "breezy.controldir", "ControlDir.hooks")
886        self.add_hook('pre_open',
887                      "Invoked before attempting to open a ControlDir with the transport "
888                      "that the open will use.", (1, 14))
889        self.add_hook('post_repo_init',
890                      "Invoked after a repository has been initialized. "
891                      "post_repo_init is called with a "
892                      "breezy.controldir.RepoInitHookParams.",
893                      (2, 2))
894
895
896# install the default hooks
897ControlDir.hooks = ControlDirHooks()
898
899
900class ControlComponentFormat(object):
901    """A component that can live inside of a control directory."""
902
903    upgrade_recommended = False
904
905    def get_format_description(self):
906        """Return the short description for this format."""
907        raise NotImplementedError(self.get_format_description)
908
909    def is_supported(self):
910        """Is this format supported?
911
912        Supported formats must be initializable and openable.
913        Unsupported formats may not support initialization or committing or
914        some other features depending on the reason for not being supported.
915        """
916        return True
917
918    def check_support_status(self, allow_unsupported, recommend_upgrade=True,
919                             basedir=None):
920        """Give an error or warning on old formats.
921
922        :param allow_unsupported: If true, allow opening
923            formats that are strongly deprecated, and which may
924            have limited functionality.
925
926        :param recommend_upgrade: If true (default), warn
927            the user through the ui object that they may wish
928            to upgrade the object.
929        """
930        if not allow_unsupported and not self.is_supported():
931            # see open_downlevel to open legacy branches.
932            raise errors.UnsupportedFormatError(format=self)
933        if recommend_upgrade and self.upgrade_recommended:
934            ui.ui_factory.recommend_upgrade(
935                self.get_format_description(), basedir)
936
937    @classmethod
938    def get_format_string(cls):
939        raise NotImplementedError(cls.get_format_string)
940
941
942class ControlComponentFormatRegistry(registry.FormatRegistry):
943    """A registry for control components (branch, workingtree, repository)."""
944
945    def __init__(self, other_registry=None):
946        super(ControlComponentFormatRegistry, self).__init__(other_registry)
947        self._extra_formats = []
948
949    def register(self, format):
950        """Register a new format."""
951        super(ControlComponentFormatRegistry, self).register(
952            format.get_format_string(), format)
953
954    def remove(self, format):
955        """Remove a registered format."""
956        super(ControlComponentFormatRegistry, self).remove(
957            format.get_format_string())
958
959    def register_extra(self, format):
960        """Register a format that can not be used in a metadir.
961
962        This is mainly useful to allow custom repository formats, such as older
963        Bazaar formats and foreign formats, to be tested.
964        """
965        self._extra_formats.append(registry._ObjectGetter(format))
966
967    def remove_extra(self, format):
968        """Remove an extra format.
969        """
970        self._extra_formats.remove(registry._ObjectGetter(format))
971
972    def register_extra_lazy(self, module_name, member_name):
973        """Register a format lazily.
974        """
975        self._extra_formats.append(
976            registry._LazyObjectGetter(module_name, member_name))
977
978    def _get_extra(self):
979        """Return getters for extra formats, not usable in meta directories."""
980        return [getter.get_obj for getter in self._extra_formats]
981
982    def _get_all_lazy(self):
983        """Return getters for all formats, even those not usable in metadirs."""
984        result = [self._dict[name].get_obj for name in self.keys()]
985        result.extend(self._get_extra())
986        return result
987
988    def _get_all(self):
989        """Return all formats, even those not usable in metadirs."""
990        result = []
991        for getter in self._get_all_lazy():
992            fmt = getter()
993            if callable(fmt):
994                fmt = fmt()
995            result.append(fmt)
996        return result
997
998    def _get_all_modules(self):
999        """Return a set of the modules providing objects."""
1000        modules = set()
1001        for name in self.keys():
1002            modules.add(self._get_module(name))
1003        for getter in self._extra_formats:
1004            modules.add(getter.get_module())
1005        return modules
1006
1007
1008class Converter(object):
1009    """Converts a disk format object from one format to another."""
1010
1011    def convert(self, to_convert, pb):
1012        """Perform the conversion of to_convert, giving feedback via pb.
1013
1014        :param to_convert: The disk object to convert.
1015        :param pb: a progress bar to use for progress information.
1016        """
1017
1018    def step(self, message):
1019        """Update the pb by a step."""
1020        self.count += 1
1021        self.pb.update(message, self.count, self.total)
1022
1023
1024class ControlDirFormat(object):
1025    """An encapsulation of the initialization and open routines for a format.
1026
1027    Formats provide three things:
1028     * An initialization routine,
1029     * a format string,
1030     * an open routine.
1031
1032    Formats are placed in a dict by their format string for reference
1033    during controldir opening. These should be subclasses of ControlDirFormat
1034    for consistency.
1035
1036    Once a format is deprecated, just deprecate the initialize and open
1037    methods on the format class. Do not deprecate the object, as the
1038    object will be created every system load.
1039
1040    :cvar colocated_branches: Whether this formats supports colocated branches.
1041    :cvar supports_workingtrees: This control directory can co-exist with a
1042        working tree.
1043    """
1044
1045    _default_format = None
1046    """The default format used for new control directories."""
1047
1048    _probers = []
1049    """The registered format probers, e.g. BzrProber.
1050
1051    This is a list of Prober-derived classes.
1052    """
1053
1054    colocated_branches = False
1055    """Whether co-located branches are supported for this control dir format.
1056    """
1057
1058    supports_workingtrees = True
1059    """Whether working trees can exist in control directories of this format.
1060    """
1061
1062    fixed_components = False
1063    """Whether components can not change format independent of the control dir.
1064    """
1065
1066    upgrade_recommended = False
1067    """Whether an upgrade from this format is recommended."""
1068
1069    def get_format_description(self):
1070        """Return the short description for this format."""
1071        raise NotImplementedError(self.get_format_description)
1072
1073    def get_converter(self, format=None):
1074        """Return the converter to use to convert controldirs needing converts.
1075
1076        This returns a breezy.controldir.Converter object.
1077
1078        This should return the best upgrader to step this format towards the
1079        current default format. In the case of plugins we can/should provide
1080        some means for them to extend the range of returnable converters.
1081
1082        :param format: Optional format to override the default format of the
1083                       library.
1084        """
1085        raise NotImplementedError(self.get_converter)
1086
1087    def is_supported(self):
1088        """Is this format supported?
1089
1090        Supported formats must be openable.
1091        Unsupported formats may not support initialization or committing or
1092        some other features depending on the reason for not being supported.
1093        """
1094        return True
1095
1096    def is_initializable(self):
1097        """Whether new control directories of this format can be initialized.
1098        """
1099        return self.is_supported()
1100
1101    def check_support_status(self, allow_unsupported, recommend_upgrade=True,
1102                             basedir=None):
1103        """Give an error or warning on old formats.
1104
1105        :param allow_unsupported: If true, allow opening
1106            formats that are strongly deprecated, and which may
1107            have limited functionality.
1108
1109        :param recommend_upgrade: If true (default), warn
1110            the user through the ui object that they may wish
1111            to upgrade the object.
1112        """
1113        if not allow_unsupported and not self.is_supported():
1114            # see open_downlevel to open legacy branches.
1115            raise errors.UnsupportedFormatError(format=self)
1116        if recommend_upgrade and self.upgrade_recommended:
1117            ui.ui_factory.recommend_upgrade(
1118                self.get_format_description(), basedir)
1119
1120    def same_model(self, target_format):
1121        return (self.repository_format.rich_root_data ==
1122                target_format.rich_root_data)
1123
1124    @classmethod
1125    def register_prober(klass, prober):
1126        """Register a prober that can look for a control dir.
1127
1128        """
1129        klass._probers.append(prober)
1130
1131    @classmethod
1132    def unregister_prober(klass, prober):
1133        """Unregister a prober.
1134
1135        """
1136        klass._probers.remove(prober)
1137
1138    def __str__(self):
1139        # Trim the newline
1140        return self.get_format_description().rstrip()
1141
1142    @classmethod
1143    def all_probers(klass):
1144        return klass._probers
1145
1146    @classmethod
1147    def known_formats(klass):
1148        """Return all the known formats.
1149        """
1150        result = []
1151        for prober_kls in klass.all_probers():
1152            result.extend(prober_kls.known_formats())
1153        return result
1154
1155    @classmethod
1156    def find_format(klass, transport, probers=None):
1157        """Return the format present at transport."""
1158        if probers is None:
1159            probers = sorted(
1160                klass.all_probers(),
1161                key=lambda prober: prober.priority(transport))
1162        for prober_kls in probers:
1163            prober = prober_kls()
1164            try:
1165                return prober.probe_transport(transport)
1166            except errors.NotBranchError:
1167                # this format does not find a control dir here.
1168                pass
1169        raise errors.NotBranchError(path=transport.base)
1170
1171    def initialize(self, url, possible_transports=None):
1172        """Create a control dir at this url and return an opened copy.
1173
1174        While not deprecated, this method is very specific and its use will
1175        lead to many round trips to setup a working environment. See
1176        initialize_on_transport_ex for a [nearly] all-in-one method.
1177
1178        Subclasses should typically override initialize_on_transport
1179        instead of this method.
1180        """
1181        return self.initialize_on_transport(
1182            _mod_transport.get_transport(url, possible_transports))
1183
1184    def initialize_on_transport(self, transport):
1185        """Initialize a new controldir in the base directory of a Transport."""
1186        raise NotImplementedError(self.initialize_on_transport)
1187
1188    def initialize_on_transport_ex(self, transport, use_existing_dir=False,
1189                                   create_prefix=False, force_new_repo=False, stacked_on=None,
1190                                   stack_on_pwd=None, repo_format_name=None, make_working_trees=None,
1191                                   shared_repo=False, vfs_only=False):
1192        """Create this format on transport.
1193
1194        The directory to initialize will be created.
1195
1196        :param force_new_repo: Do not use a shared repository for the target,
1197                               even if one is available.
1198        :param create_prefix: Create any missing directories leading up to
1199            to_transport.
1200        :param use_existing_dir: Use an existing directory if one exists.
1201        :param stacked_on: A url to stack any created branch on, None to follow
1202            any target stacking policy.
1203        :param stack_on_pwd: If stack_on is relative, the location it is
1204            relative to.
1205        :param repo_format_name: If non-None, a repository will be
1206            made-or-found. Should none be found, or if force_new_repo is True
1207            the repo_format_name is used to select the format of repository to
1208            create.
1209        :param make_working_trees: Control the setting of make_working_trees
1210            for a new shared repository when one is made. None to use whatever
1211            default the format has.
1212        :param shared_repo: Control whether made repositories are shared or
1213            not.
1214        :param vfs_only: If True do not attempt to use a smart server
1215        :return: repo, controldir, require_stacking, repository_policy. repo is
1216            None if none was created or found, controldir is always valid.
1217            require_stacking is the result of examining the stacked_on
1218            parameter and any stacking policy found for the target.
1219        """
1220        raise NotImplementedError(self.initialize_on_transport_ex)
1221
1222    def network_name(self):
1223        """A simple byte string uniquely identifying this format for RPC calls.
1224
1225        Bzr control formats use this disk format string to identify the format
1226        over the wire. Its possible that other control formats have more
1227        complex detection requirements, so we permit them to use any unique and
1228        immutable string they desire.
1229        """
1230        raise NotImplementedError(self.network_name)
1231
1232    def open(self, transport, _found=False):
1233        """Return an instance of this format for the dir transport points at.
1234        """
1235        raise NotImplementedError(self.open)
1236
1237    @classmethod
1238    def _set_default_format(klass, format):
1239        """Set default format (for testing behavior of defaults only)"""
1240        klass._default_format = format
1241
1242    @classmethod
1243    def get_default_format(klass):
1244        """Return the current default format."""
1245        return klass._default_format
1246
1247    def supports_transport(self, transport):
1248        """Check if this format can be opened over a particular transport.
1249        """
1250        raise NotImplementedError(self.supports_transport)
1251
1252    @classmethod
1253    def is_control_filename(klass, filename):
1254        """True if filename is the name of a path which is reserved for
1255        controldirs.
1256
1257        :param filename: A filename within the root transport of this
1258            controldir.
1259
1260        This is true IF and ONLY IF the filename is part of the namespace reserved
1261        for bzr control dirs. Currently this is the '.bzr' directory in the root
1262        of the root_transport. it is expected that plugins will need to extend
1263        this in the future - for instance to make bzr talk with svn working
1264        trees.
1265        """
1266        raise NotImplementedError(self.is_control_filename)
1267
1268
1269class Prober(object):
1270    """Abstract class that can be used to detect a particular kind of
1271    control directory.
1272
1273    At the moment this just contains a single method to probe a particular
1274    transport, but it may be extended in the future to e.g. avoid
1275    multiple levels of probing for Subversion repositories.
1276
1277    See BzrProber and RemoteBzrProber in breezy.bzrdir for the
1278    probers that detect .bzr/ directories and Bazaar smart servers,
1279    respectively.
1280
1281    Probers should be registered using the register_prober methods on
1282    ControlDirFormat.
1283    """
1284
1285    def probe_transport(self, transport):
1286        """Return the controldir style format present in a directory.
1287
1288        :raise UnknownFormatError: If a control dir was found but is
1289            in an unknown format.
1290        :raise NotBranchError: If no control directory was found.
1291        :return: A ControlDirFormat instance.
1292        """
1293        raise NotImplementedError(self.probe_transport)
1294
1295    @classmethod
1296    def known_formats(klass):
1297        """Return the control dir formats known by this prober.
1298
1299        Multiple probers can return the same formats, so this should
1300        return a set.
1301
1302        :return: A set of known formats.
1303        """
1304        raise NotImplementedError(klass.known_formats)
1305
1306    @classmethod
1307    def priority(klass, transport):
1308        """Priority of this prober.
1309
1310        A lower value means the prober gets checked first.
1311
1312        Other conventions:
1313
1314        -10: This is a "server" prober
1315        0: No priority set
1316        10: This is a regular file-based prober
1317        100: This is a prober for an unsupported format
1318        """
1319        return 0
1320
1321
1322class ControlDirFormatInfo(object):
1323
1324    def __init__(self, native, deprecated, hidden, experimental):
1325        self.deprecated = deprecated
1326        self.native = native
1327        self.hidden = hidden
1328        self.experimental = experimental
1329
1330
1331class ControlDirFormatRegistry(registry.Registry):
1332    """Registry of user-selectable ControlDir subformats.
1333
1334    Differs from ControlDirFormat._formats in that it provides sub-formats,
1335    e.g. BzrDirMeta1 with weave repository.  Also, it's more user-oriented.
1336    """
1337
1338    def __init__(self):
1339        """Create a ControlDirFormatRegistry."""
1340        self._registration_order = list()
1341        super(ControlDirFormatRegistry, self).__init__()
1342
1343    def register(self, key, factory, help, native=True, deprecated=False,
1344                 hidden=False, experimental=False):
1345        """Register a ControlDirFormat factory.
1346
1347        The factory must be a callable that takes one parameter: the key.
1348        It must produce an instance of the ControlDirFormat when called.
1349
1350        This function mainly exists to prevent the info object from being
1351        supplied directly.
1352        """
1353        registry.Registry.register(self, key, factory, help,
1354                                   ControlDirFormatInfo(native, deprecated, hidden, experimental))
1355        self._registration_order.append(key)
1356
1357    def register_alias(self, key, target, hidden=False):
1358        """Register a format alias.
1359
1360        :param key: Alias name
1361        :param target: Target format
1362        :param hidden: Whether the alias is hidden
1363        """
1364        info = self.get_info(target)
1365        registry.Registry.register_alias(self, key, target,
1366                                         ControlDirFormatInfo(
1367                                             native=info.native, deprecated=info.deprecated,
1368                                             hidden=hidden, experimental=info.experimental))
1369
1370    def register_lazy(self, key, module_name, member_name, help, native=True,
1371                      deprecated=False, hidden=False, experimental=False):
1372        registry.Registry.register_lazy(self, key, module_name, member_name,
1373                                        help, ControlDirFormatInfo(native, deprecated, hidden, experimental))
1374        self._registration_order.append(key)
1375
1376    def set_default(self, key):
1377        """Set the 'default' key to be a clone of the supplied key.
1378
1379        This method must be called once and only once.
1380        """
1381        self.register_alias('default', key)
1382
1383    def set_default_repository(self, key):
1384        """Set the FormatRegistry default and Repository default.
1385
1386        This is a transitional method while Repository.set_default_format
1387        is deprecated.
1388        """
1389        if 'default' in self:
1390            self.remove('default')
1391        self.set_default(key)
1392        format = self.get('default')()
1393
1394    def make_controldir(self, key):
1395        return self.get(key)()
1396
1397    def help_topic(self, topic):
1398        output = ""
1399        default_realkey = None
1400        default_help = self.get_help('default')
1401        help_pairs = []
1402        for key in self._registration_order:
1403            if key == 'default':
1404                continue
1405            help = self.get_help(key)
1406            if help == default_help:
1407                default_realkey = key
1408            else:
1409                help_pairs.append((key, help))
1410
1411        def wrapped(key, help, info):
1412            if info.native:
1413                help = '(native) ' + help
1414            return ':%s:\n%s\n\n' % (key,
1415                                     textwrap.fill(help, initial_indent='    ',
1416                                                   subsequent_indent='    ',
1417                                                   break_long_words=False))
1418        if default_realkey is not None:
1419            output += wrapped(default_realkey, '(default) %s' % default_help,
1420                              self.get_info('default'))
1421        deprecated_pairs = []
1422        experimental_pairs = []
1423        for key, help in help_pairs:
1424            info = self.get_info(key)
1425            if info.hidden:
1426                continue
1427            elif info.deprecated:
1428                deprecated_pairs.append((key, help))
1429            elif info.experimental:
1430                experimental_pairs.append((key, help))
1431            else:
1432                output += wrapped(key, help, info)
1433        output += "\nSee :doc:`formats-help` for more about storage formats."
1434        other_output = ""
1435        if len(experimental_pairs) > 0:
1436            other_output += "Experimental formats are shown below.\n\n"
1437            for key, help in experimental_pairs:
1438                info = self.get_info(key)
1439                other_output += wrapped(key, help, info)
1440        else:
1441            other_output += \
1442                "No experimental formats are available.\n\n"
1443        if len(deprecated_pairs) > 0:
1444            other_output += "\nDeprecated formats are shown below.\n\n"
1445            for key, help in deprecated_pairs:
1446                info = self.get_info(key)
1447                other_output += wrapped(key, help, info)
1448        else:
1449            other_output += \
1450                "\nNo deprecated formats are available.\n\n"
1451        other_output += \
1452            "\nSee :doc:`formats-help` for more about storage formats."
1453
1454        if topic == 'other-formats':
1455            return other_output
1456        else:
1457            return output
1458
1459
1460class RepoInitHookParams(object):
1461    """Object holding parameters passed to `*_repo_init` hooks.
1462
1463    There are 4 fields that hooks may wish to access:
1464
1465    :ivar repository: Repository created
1466    :ivar format: Repository format
1467    :ivar bzrdir: The controldir for the repository
1468    :ivar shared: The repository is shared
1469    """
1470
1471    def __init__(self, repository, format, controldir, shared):
1472        """Create a group of RepoInitHook parameters.
1473
1474        :param repository: Repository created
1475        :param format: Repository format
1476        :param controldir: The controldir for the repository
1477        :param shared: The repository is shared
1478        """
1479        self.repository = repository
1480        self.format = format
1481        self.controldir = controldir
1482        self.shared = shared
1483
1484    def __eq__(self, other):
1485        return self.__dict__ == other.__dict__
1486
1487    def __repr__(self):
1488        if self.repository:
1489            return "<%s for %s>" % (self.__class__.__name__,
1490                                    self.repository)
1491        else:
1492            return "<%s for %s>" % (self.__class__.__name__,
1493                                    self.controldir)
1494
1495
1496def is_control_filename(filename):
1497    """Check if filename is used for control directories."""
1498    # TODO(jelmer): Instead, have a function that returns all control
1499    # filenames.
1500    for key, format in format_registry.items():
1501        if format().is_control_filename(filename):
1502            return True
1503    else:
1504        return False
1505
1506
1507class RepositoryAcquisitionPolicy(object):
1508    """Abstract base class for repository acquisition policies.
1509
1510    A repository acquisition policy decides how a ControlDir acquires a repository
1511    for a branch that is being created.  The most basic policy decision is
1512    whether to create a new repository or use an existing one.
1513    """
1514
1515    def __init__(self, stack_on, stack_on_pwd, require_stacking):
1516        """Constructor.
1517
1518        :param stack_on: A location to stack on
1519        :param stack_on_pwd: If stack_on is relative, the location it is
1520            relative to.
1521        :param require_stacking: If True, it is a failure to not stack.
1522        """
1523        self._stack_on = stack_on
1524        self._stack_on_pwd = stack_on_pwd
1525        self._require_stacking = require_stacking
1526
1527    def configure_branch(self, branch):
1528        """Apply any configuration data from this policy to the branch.
1529
1530        Default implementation sets repository stacking.
1531        """
1532        if self._stack_on is None:
1533            return
1534        if self._stack_on_pwd is None:
1535            stack_on = self._stack_on
1536        else:
1537            try:
1538                stack_on = urlutils.rebase_url(self._stack_on,
1539                                               self._stack_on_pwd,
1540                                               branch.user_url)
1541            except urlutils.InvalidRebaseURLs:
1542                stack_on = self._get_full_stack_on()
1543        try:
1544            branch.set_stacked_on_url(stack_on)
1545        except (_mod_branch.UnstackableBranchFormat,
1546                errors.UnstackableRepositoryFormat):
1547            if self._require_stacking:
1548                raise
1549
1550    def requires_stacking(self):
1551        """Return True if this policy requires stacking."""
1552        return self._stack_on is not None and self._require_stacking
1553
1554    def _get_full_stack_on(self):
1555        """Get a fully-qualified URL for the stack_on location."""
1556        if self._stack_on is None:
1557            return None
1558        if self._stack_on_pwd is None:
1559            return self._stack_on
1560        else:
1561            return urlutils.join(self._stack_on_pwd, self._stack_on)
1562
1563    def _add_fallback(self, repository, possible_transports=None):
1564        """Add a fallback to the supplied repository, if stacking is set."""
1565        stack_on = self._get_full_stack_on()
1566        if stack_on is None:
1567            return
1568        try:
1569            stacked_dir = ControlDir.open(
1570                stack_on, possible_transports=possible_transports)
1571        except errors.JailBreak:
1572            # We keep the stacking details, but we are in the server code so
1573            # actually stacking is not needed.
1574            return
1575        try:
1576            stacked_repo = stacked_dir.open_branch().repository
1577        except errors.NotBranchError:
1578            stacked_repo = stacked_dir.open_repository()
1579        try:
1580            repository.add_fallback_repository(stacked_repo)
1581        except errors.UnstackableRepositoryFormat:
1582            if self._require_stacking:
1583                raise
1584        else:
1585            self._require_stacking = True
1586
1587    def acquire_repository(self, make_working_trees=None, shared=False,
1588                           possible_transports=None):
1589        """Acquire a repository for this controlrdir.
1590
1591        Implementations may create a new repository or use a pre-exising
1592        repository.
1593
1594        :param make_working_trees: If creating a repository, set
1595            make_working_trees to this value (if non-None)
1596        :param shared: If creating a repository, make it shared if True
1597        :return: A repository, is_new_flag (True if the repository was
1598            created).
1599        """
1600        raise NotImplementedError(
1601            RepositoryAcquisitionPolicy.acquire_repository)
1602
1603
1604# Please register new formats after old formats so that formats
1605# appear in chronological order and format descriptions can build
1606# on previous ones.
1607format_registry = ControlDirFormatRegistry()
1608
1609network_format_registry = registry.FormatRegistry()
1610"""Registry of formats indexed by their network name.
1611
1612The network name for a ControlDirFormat is an identifier that can be used when
1613referring to formats with smart server operations. See
1614ControlDirFormat.network_name() for more detail.
1615"""
1616