/brz/remove-bazaar

# Copyright (C) 2008 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

r"""FastImport Plugin

=================

The fastimport plugin provides stream-based importing and exporting of

data into and out of Bazaar. As well as enabling interchange between

multiple VCS tools, fastimport/export can be useful for complex branch

operations, e.g. partitioning off part of a code base in order to Open

Source it.

The normal import recipe is::

  bzr fast-export-from-xxx SOURCE project.fi

  bzr fast-import project.fi project.bzr

If fast-export-from-xxx doesn't exist yet for the tool you're importing

from, the alternative recipe is::

  front-end > project.fi

  bzr fast-import project.fi project.bzr

In either case, if you wish to save disk space, project.fi can be

compressed to gzip format after it is generated like this::

  (generate project.fi)

  gzip project.fi

  bzr fast-import project.fi.gz project.bzr

The list of known front-ends and their status is documented on

http://bazaar-vcs.org/BzrFastImport/FrontEnds. The fast-export-from-xxx

commands provide simplified access to these so that the majority of users

can generate a fast-import dump file without needing to study up on all

the options - and the best combination of them to use - for the front-end

relevant to them. In some cases, a fast-export-from-xxx wrapper will require

that certain dependencies are installed so it checks for these before

starting. A wrapper may also provide a limited set of options. See the

online help for the individual commands for details::

  bzr help fast-export-from-cvs

  bzr help fast-export-from-darcs

  bzr help fast-export-from-hg

  bzr help fast-export-from-git

  bzr help fast-export-from-mtn

  bzr help fast-export-from-p4

  bzr help fast-export-from-svn

Once a fast-import dump file is created, it can be imported into a

Bazaar repository using the fast-import command. If required, you can

manipulate the stream first using the fast-import-filter command.

This is useful for creating a repository with just part of a project

or for removing large old binaries (say) from history that are no longer

valuable to retain. For further details on importing, manipulating and

reporting on fast-import streams, see the online help for the commands::

  bzr help fast-import

  bzr help fast-import-filter

  bzr help fast-import-info

  bzr help fast-import-query

Finally, you may wish to generate a fast-import dump file from a Bazaar

repository. The fast-export command is provided for that purpose.

To report bugs or publish enhancements, visit the bzr-fastimport project

page on Launchpad, https://launchpad.net/bzr-fastimport.

"""

version_info = (0, 10, 0, 'dev', 0)

from bzrlib import bzrdir

from bzrlib.commands import Command, register_command

from bzrlib.option import Option, ListOption, RegistryOption

def load_fastimport():

    """Load the fastimport module or raise an appropriate exception."""

    try:

        import fastimport

    except ImportError, e:

        from bzrlib.errors import DependencyNotPresent

        raise DependencyNotPresent("fastimport", e)

def test_suite():

    import tests

    return tests.test_suite()

def _run(source, processor_factory, control, params, verbose,

    user_map=None):

    """Create and run a processor.

    :param source: a filename or '-' for standard input. If the

      filename ends in .gz, it will be opened as a gzip file and

      the stream will be implicitly uncompressed

    :param processor_factory: a callable for creating a processor

    :param control: the BzrDir of the destination or None if no

      destination is expected

    :param user_map: if not None, the file containing the user map.

    """

    from fastimport import parser

    stream = _get_source_stream(source)

    user_mapper = _get_user_mapper(user_map)

    proc = processor_factory(control, params=params, verbose=verbose)

    p = parser.ImportParser(stream, verbose=verbose, user_mapper=user_mapper)

    return proc.process(p.iter_commands)

def _get_source_stream(source):

    if source == '-':

        import sys

        from fastimport import helpers

        stream = helpers.binary_stream(sys.stdin)

    elif source.endswith('.gz'):

        import gzip

        stream = gzip.open(source, "rb")

    else:

        stream = open(source, "rb")

    return stream

def _get_user_mapper(filename):

    import user_mapper

    if filename is None:

        return None

    f = open(filename)

    lines = f.readlines()

    f.close()

    return user_mapper.UserMapper(lines)

class cmd_fast_import(Command):

    """Backend for fast Bazaar data importers.

    This command reads a mixed command/data stream and creates

    branches in a Bazaar repository accordingly. The preferred

    recipe is::

      bzr fast-import project.fi project.bzr

    Numerous commands are provided for generating a fast-import file

    to use as input. These are named fast-export-from-xxx where xxx

    is one of cvs, darcs, git, hg, mtn, p4 or svn.

    To specify standard input as the input stream, use a

    source name of '-' (instead of project.fi). If the source name

    ends in '.gz', it is assumed to be compressed in gzip format.

    project.bzr will be created if it doesn't exist. If it exists

    already, it should be empty or be an existing Bazaar repository

    or branch. If not specified, the current directory is assumed.

    fast-import will intelligently select the format to use when

    creating a repository or branch. If you are running Bazaar 1.17

    up to Bazaar 2.0, the default format for Bazaar 2.x ("2a") is used.

    Otherwise, the current default format ("pack-0.92" for Bazaar 1.x)

    is used. If you wish to specify a custom format, use the `--format`

    option.

     .. note::

        To maintain backwards compatibility, fast-import lets you

        create the target repository or standalone branch yourself.

        It is recommended though that you let fast-import create

        these for you instead.

    :Branch mapping rules:

     Git reference names are mapped to Bazaar branch names as follows:

     * refs/heads/foo is mapped to foo

     * refs/remotes/origin/foo is mapped to foo.remote

     * refs/tags/foo is mapped to foo.tag

     * */master is mapped to trunk, trunk.remote, etc.

     * */trunk is mapped to git-trunk, git-trunk.remote, etc.

    :Branch creation rules:

     When a shared repository is created or found at the destination,

     branches are created inside it. In the simple case of a single

     branch (refs/heads/master) inside the input file, the branch is

     project.bzr/trunk.

     When a standalone branch is found at the destination, the trunk

     is imported there and warnings are output about any other branches

     found in the input file.

     When a branch in a shared repository is found at the destination,

     that branch is made the trunk and other branches, if any, are

     created in sister directories.

    :Working tree updates:

     The working tree is generated for the trunk branch. If multiple

     branches are created, a message is output on completion explaining

     how to create the working trees for other branches.

    :Custom exporters:

     The fast-export-from-xxx commands typically call more advanced

     xxx-fast-export scripts. You are welcome to use the advanced

     scripts if you prefer.

     If you wish to write a custom exporter for your project, see

     http://bazaar-vcs.org/BzrFastImport for the detailed protocol

     specification. In many cases, exporters can be written quite

     quickly using whatever scripting/programming language you like.

    :User mapping:

     Some source repositories store just the user name while Bazaar

     prefers a full email address. You can adjust user-ids while

     importing by using the --user-map option. The argument is a

     text file with lines in the format::

       old-id = new-id

     Blank lines and lines beginning with # are ignored.

     If old-id has the special value '@', then users without an

     email address will get one created by using the matching new-id

     as the domain, unless a more explicit address is given for them.

     For example, given the user-map of::

       @ = example.com

       bill = William Jones <bill@example.com>

     then user-ids are mapped as follows::

      maria => maria <maria@example.com>

      bill => William Jones <bill@example.com>

     .. note::

        User mapping is supported by both the fast-import and

        fast-import-filter commands.

    :Blob tracking:

     As some exporters (like git-fast-export) reuse blob data across

     commits, fast-import makes two passes over the input file by

     default. In the first pass, it collects data about what blobs are

     used when, along with some other statistics (e.g. total number of

     commits). In the second pass, it generates the repository and

     branches.

     .. note::

        The initial pass isn't done if the --info option is used

        to explicitly pass in information about the input stream.

        It also isn't done if the source is standard input. In the

        latter case, memory consumption may be higher than otherwise

        because some blobs may be kept in memory longer than necessary.

    :Restarting an import:

     At checkpoints and on completion, the commit-id -> revision-id

     map is saved to a file called 'fastimport-id-map' in the control

     directory for the repository (e.g. .bzr/repository). If the import

     is interrupted or unexpectedly crashes, it can be started again

     and this file will be used to skip over already loaded revisions.

     As long as subsequent exports from the original source begin

     with exactly the same revisions, you can use this feature to

     maintain a mirror of a repository managed by a foreign tool.

     If and when Bazaar is used to manage the repository, this file

     can be safely deleted.

    :Examples:

     Import a Subversion repository into Bazaar::

       bzr fast-export-from-svn /svn/repo/path project.fi

       bzr fast-import project.fi project.bzr

     Import a CVS repository into Bazaar::

       bzr fast-export-from-cvs /cvs/repo/path project.fi

       bzr fast-import project.fi project.bzr

     Import a Git repository into Bazaar::

       bzr fast-export-from-git /git/repo/path project.fi

       bzr fast-import project.fi project.bzr

     Import a Mercurial repository into Bazaar::

       bzr fast-export-from-hg /hg/repo/path project.fi

       bzr fast-import project.fi project.bzr

     Import a Darcs repository into Bazaar::

       bzr fast-export-from-darcs /darcs/repo/path project.fi

       bzr fast-import project.fi project.bzr

    """

    hidden = False

    _see_also = ['fast-export', 'fast-import-filter', 'fast-import-info']

    takes_args = ['source', 'destination?']

    takes_options = ['verbose',

                    Option('user-map', type=str,

                        help="Path to file containing a map of user-ids.",

                        ),

                    Option('info', type=str,

                        help="Path to file containing caching hints.",

                        ),

                    Option('trees',

                        help="Update all working trees, not just trunk's.",

                        ),

                    Option('count', type=int,

                        help="Import this many revisions then exit.",

                        ),

                    Option('checkpoint', type=int,

                        help="Checkpoint automatically every N revisions."

                             " The default is 10000.",

                        ),

                    Option('autopack', type=int,

                        help="Pack every N checkpoints. The default is 4.",

                        ),

                    Option('inv-cache', type=int,

                        help="Number of inventories to cache.",

                        ),

                    RegistryOption.from_kwargs('mode',

                        'The import algorithm to use.',

                        title='Import Algorithm',

                        default='Use the preferred algorithm (inventory deltas).',

                        classic="Use the original algorithm (mutable inventories).",

                        experimental="Enable experimental features.",

                        value_switches=True, enum_switch=False,

                        ),

                    Option('import-marks', type=str,

                        help="Import marks from file."

                        ),

                    Option('export-marks', type=str,

                        help="Export marks to file."

                        ),

                    RegistryOption('format',

                            help='Specify a format for the created repository. See'

                                 ' "bzr help formats" for details.',

                            lazy_registry=('bzrlib.bzrdir', 'format_registry'),

                            converter=lambda name: bzrdir.format_registry.make_bzrdir(name),

                            value_switches=False, title='Repository format'),

                     ]

    aliases = []

    def run(self, source, destination='.', verbose=False, info=None,

        trees=False, count=-1, checkpoint=10000, autopack=4, inv_cache=-1,

        mode=None, import_marks=None, export_marks=None, format=None,

        user_map=None):

        load_fastimport()

        from bzrlib.plugins.fastimport.processors import generic_processor

        from bzrlib.plugins.fastimport.helpers import (

            open_destination_directory,

            )

        # If no format is given and the user is running a release

        # leading up to 2.0, select 2a for them. Otherwise, use

        # the default format.

        if format is None:

            import bzrlib

            bzr_version = bzrlib.version_info[0:2]

            if bzr_version in [(1,17), (1,18), (2,0)]:

                format = bzrdir.format_registry.make_bzrdir('2a')

        control = open_destination_directory(destination, format=format)

        # If an information file was given and the source isn't stdin,

        # generate the information by reading the source file as a first pass

        if info is None and source != '-':

            info = self._generate_info(source)

        # Do the work

        if mode is None:

            mode = 'default'

        params = {

            'info': info,

            'trees': trees,

            'count': count,

            'checkpoint': checkpoint,

            'autopack': autopack,

            'inv-cache': inv_cache,

            'mode': mode,

            'import-marks': import_marks,

            'export-marks': export_marks,

            }

        return _run(source, generic_processor.GenericProcessor, control,

            params, verbose, user_map=user_map)

    def _generate_info(self, source):

        from cStringIO import StringIO

        from fastimport import parser

        from fastimport.processors import info_processor

        stream = _get_source_stream(source)

        output = StringIO()

        try:

            proc = info_processor.InfoProcessor(verbose=True, outf=output)

            p = parser.ImportParser(stream)

            return_code = proc.process(p.iter_commands)

            lines = output.getvalue().splitlines()

        finally:

            output.close()

            stream.seek(0)

        return lines

class cmd_fast_import_filter(Command):

    """Filter a fast-import stream to include/exclude files & directories.

    This command is useful for splitting a subdirectory or bunch of

    files out from a project to create a new project complete with history

    for just those files. It can also be used to create a new project

    repository that removes all references to files that should not have

    been committed, e.g. security-related information (like passwords),

    commercially sensitive material, files with an incompatible license or

    large binary files like CD images.

    To specify standard input as the input stream, use a source name

    of '-'. If the source name ends in '.gz', it is assumed to be

    compressed in gzip format.

    :File/directory filtering:

     This is supported by the -i and -x options. Excludes take precedence

     over includes.

     When filtering out a subdirectory (or file), the new stream uses the

     subdirectory (or subdirectory containing the file) as the root. As

     fast-import doesn't know in advance whether a path is a file or

     directory in the stream, you need to specify a trailing '/' on

     directories passed to the `--includes option`. If multiple files or

     directories are given, the new root is the deepest common directory.

     Note: If a path has been renamed, take care to specify the *original*

     path name, not the final name that it ends up with.

    :User mapping:

     Some source repositories store just the user name while Bazaar

     prefers a full email address. You can adjust user-ids

     by using the --user-map option. The argument is a

     text file with lines in the format::

       old-id = new-id

     Blank lines and lines beginning with # are ignored.

     If old-id has the special value '@', then users without an

     email address will get one created by using the matching new-id

     as the domain, unless a more explicit address is given for them.

     For example, given the user-map of::

       @ = example.com

       bill = William Jones <bill@example.com>

     then user-ids are mapped as follows::

      maria => maria <maria@example.com>

      bill => William Jones <bill@example.com>

     .. note::

        User mapping is supported by both the fast-import and

        fast-import-filter commands.

    :Examples:

     Create a new project from a library (note the trailing / on the

     directory name of the library)::

       front-end | bzr fast-import-filter -i lib/xxx/ > xxx.fi

       bzr fast-import xxx.fi mylibrary.bzr

       (lib/xxx/foo is now foo)

     Create a new repository without a sensitive file::

       front-end | bzr fast-import-filter -x missile-codes.txt > clean.fi

       bzr fast-import clean.fi clean.bzr

    """

    hidden = False

    _see_also = ['fast-import']

    takes_args = ['source']

    takes_options = ['verbose',

                    ListOption('include_paths', short_name='i', type=str,

                        help="Only include commits affecting these paths."

                             " Directories should have a trailing /."

                        ),

                    ListOption('exclude_paths', short_name='x', type=str,

                        help="Exclude these paths from commits."

                        ),

                    Option('user-map', type=str,

                        help="Path to file containing a map of user-ids.",

                        ),

                     ]

    aliases = []

    encoding_type = 'exact'

    def run(self, source, verbose=False, include_paths=None,

        exclude_paths=None, user_map=None):

        load_fastimport()

        from fastimport.processors import filter_processor

        params = {

            'include_paths': include_paths,

            'exclude_paths': exclude_paths,

            }

        return _run(source, filter_processor.FilterProcessor, params,

            verbose, user_map=user_map)

class cmd_fast_import_info(Command):

    """Output information about a fast-import stream.

    This command reads a fast-import stream and outputs

    statistics and interesting properties about what it finds.

    When run in verbose mode, the information is output as a

    configuration file that can be passed to fast-import to

    assist it in intelligently caching objects.

    To specify standard input as the input stream, use a source name

    of '-'. If the source name ends in '.gz', it is assumed to be

    compressed in gzip format.

    :Examples:

     Display statistics about the import stream produced by front-end::

      front-end | bzr fast-import-info -

     Create a hints file for running fast-import on a large repository::

       front-end | bzr fast-import-info -v - > front-end.cfg

    """

    hidden = False

    _see_also = ['fast-import']

    takes_args = ['source']

    takes_options = ['verbose']

    aliases = []

    def run(self, source, verbose=False):

        load_fastimport()

        from fastimport.processors import info_processor

        return _run(source, info_processor.InfoProcessor, {}, verbose)

class cmd_fast_import_query(Command):

    """Query a fast-import stream displaying selected commands.

    To specify standard input as the input stream, use a source name

    of '-'. If the source name ends in '.gz', it is assumed to be

    compressed in gzip format.

    To specify a commit to display, give its mark using the

    --commit-mark option. The commit will be displayed with

    file-commands included but with inline blobs hidden.

    To specify the commands to display, use the -C option one or

    more times. To specify just some fields for a command, use the

    syntax::

      command=field1,...

    By default, the nominated fields for the nominated commands

    are displayed tab separated. To see the information in

    a name:value format, use verbose mode.

    Note: Binary fields (e.g. data for blobs) are masked out

    so it is generally safe to view the output in a terminal.

    :Examples:

     Show the commit with mark 429::

      bzr fast-import-query xxx.fi -m429

     Show all the fields of the reset and tag commands::

      bzr fast-import-query xxx.fi -Creset -Ctag

     Show the mark and merge fields of the commit commands::

      bzr fast-import-query xxx.fi -Ccommit=mark,merge

    """

    hidden = True

    _see_also = ['fast-import', 'fast-import-filter']

    takes_args = ['source']

    takes_options = ['verbose',

                    Option('commit-mark', short_name='m', type=str,

                        help="Mark of the commit to display."

                        ),

                    ListOption('commands', short_name='C', type=str,

                        help="Display fields for these commands."

                        ),

                     ]

    aliases = []

    def run(self, source, verbose=False, commands=None, commit_mark=None):

        load_fastimport()

        from fastimport.processors import query_processor

        from bzrlib.plugins.fastimport import helpers

        params = helpers.defines_to_dict(commands) or {}

        if commit_mark:

            params['commit-mark'] = commit_mark

        return _run(source, query_processor.QueryProcessor, params,

            verbose)

class cmd_fast_export(Command):

    """Generate a fast-import stream from a Bazaar branch.

    This program generates a stream from a Bazaar branch in fast-import

    format used by tools such as bzr fast-import, git-fast-import and

    hg-fast-import.

    If no destination is given or the destination is '-', standard output

    is used. Otherwise, the destination is the name of a file. If the

    destination ends in '.gz', the output will be compressed into gzip

    format.

    :Round-tripping:

     Recent versions of the fast-import specification support features

     that allow effective round-tripping of many Bazaar branches. As

     such, fast-exporting a branch and fast-importing the data produced

     will create a new repository with equivalent history, i.e.

     "bzr log -v -p --include-merges --forward" on the old branch and

     new branch should produce similar, if not identical, results.

     .. note::

        Be aware that the new repository may appear to have similar history

        but internally it is quite different with new revision-ids and

        file-ids assigned. As a consequence, the ability to easily merge

        with branches based on the old repository is lost. Depending on your

        reasons for producing a new repository, this may or may not be an

        issue.

    :Interoperability:

     fast-export can use the following "extended features" to

     produce a richer data stream:

     * *multiple-authors* - if a commit has multiple authors (as commonly

       occurs in pair-programming), all authors will be included in the

       output, not just the first author

     * *commit-properties* - custom metadata per commit that Bazaar stores

       in revision properties (e.g. branch-nick and bugs fixed by this

       change) will be included in the output.

     * *empty-directories* - directories, even the empty ones, will be

       included in the output.

     To disable these features and produce output acceptable to git 1.6,

     use the --plain option. To enable these features, use --no-plain.

     Currently, --plain is the default but that will change in the near

     future once the feature names and definitions are formally agreed

     to by the broader fast-import developer community.

    :Examples:

     To produce data destined for import into Bazaar::

       bzr fast-export --no-plain my-bzr-branch my.fi.gz

     To produce data destined for Git 1.6::

       bzr fast-export --plain my-bzr-branch my.fi

     To import several unmerged but related branches into the same repository,

     use the --{export,import}-marks options, and specify a name for the git

     branch like this::

       bzr fast-export --export-marks=marks.bzr project.dev |

              GIT_DIR=project/.git git-fast-import --export-marks=marks.git

       bzr fast-export --import-marks=marks.bzr -b other project.other |

              GIT_DIR=project/.git git-fast-import --import-marks=marks.git

     If you get a "Missing space after source" error from git-fast-import,

     see the top of the commands.py module for a work-around.

    """

    hidden = False

    _see_also = ['fast-import', 'fast-import-filter']

    takes_args = ['source', 'destination?']

    takes_options = ['verbose', 'revision',

                    Option('git-branch', short_name='b', type=str,

                        argname='FILE',

                        help='Name of the git branch to create (default=master).'

                        ),

                    Option('checkpoint', type=int, argname='N',

                        help="Checkpoint every N revisions (default=10000)."

                        ),

                    Option('marks', type=str, argname='FILE',

                        help="Import marks from and export marks to file."

                        ),

                    Option('import-marks', type=str, argname='FILE',

                        help="Import marks from file."

                        ),

                    Option('export-marks', type=str, argname='FILE',

                        help="Export marks to file."

                        ),

                    Option('plain',

                        help="Exclude metadata to maximise interoperability."

                        ),

                     ]

    aliases = []

    encoding_type = 'exact'

    def run(self, source, destination=None, verbose=False,

        git_branch="master", checkpoint=10000, marks=None,

        import_marks=None, export_marks=None, revision=None,

        plain=True):

        load_fastimport()

        from bzrlib.plugins.fastimport import exporter

        if marks:

            import_marks = export_marks = marks

        exporter = exporter.BzrFastExporter(source,

            destination=destination,

            git_branch=git_branch, checkpoint=checkpoint,

            import_marks_file=import_marks, export_marks_file=export_marks,

            revision=revision, verbose=verbose, plain_format=plain)

        return exporter.run()

class cmd_fast_export_from_cvs(Command):

    """Generate a fast-import file from a CVS repository.

    Destination is a dump file, typically named xxx.fi where xxx is

    the name of the project. If '-' is given, standard output is used.

    cvs2svn 2.3 or later must be installed as its cvs2bzr script is used

    under the covers to do the export.

    The source must be the path on your filesystem to the part of the

    repository you wish to convert. i.e. either that path or a parent

    directory must contain a CVSROOT subdirectory. The path may point to

    either the top of a repository or to a path within it. In the latter

    case, only that project within the repository will be converted.

    .. note::

       Remote access to the repository is not sufficient - the path

       must point into a copy of the repository itself. See

       http://cvs2svn.tigris.org/faq.html#repoaccess for instructions

       on how to clone a remote CVS repository locally.

    By default, the trunk, branches and tags are all exported. If you

    only want the trunk, use the `--trunk-only` option.

    By default, filenames, log messages and author names are expected

    to be encoded in ascii. Use the `--encoding` option to specify an

    alternative. If multiple encodings are used, specify the option

    multiple times. For a list of valid encoding names, see

    http://docs.python.org/lib/standard-encodings.html.

    Windows users need to install GNU sort and use the `--sort`

    option to specify its location. GNU sort can be downloaded from

    http://unxutils.sourceforge.net/.

    """

    hidden = False

    _see_also = ['fast-import', 'fast-import-filter']

    takes_args = ['source', 'destination']

    takes_options = ['verbose',

                    Option('trunk-only',

                        help="Export just the trunk, ignoring tags and branches."

                        ),

                    ListOption('encoding', type=str, argname='CODEC',

                        help="Encoding used for filenames, commit messages "

                             "and author names if not ascii."

                        ),

                    Option('sort', type=str, argname='PATH',

                        help="GNU sort program location if not on the path."

                        ),

                    ]

    aliases = []

    encoding_type = 'exact'

    def run(self, source, destination, verbose=False, trunk_only=False,

        encoding=None, sort=None):

        load_fastimport()

        from bzrlib.plugins.fastimport.exporters import fast_export_from

        custom = []

        if trunk_only:

            custom.append("--trunk-only")

        if encoding:

            for enc in encoding:

                custom.extend(['--encoding', enc])

        if sort:

            custom.extend(['--sort', sort])

        fast_export_from(source, destination, 'cvs', verbose, custom)

class cmd_fast_export_from_darcs(Command):

    """Generate a fast-import file from a Darcs repository.

    Destination is a dump file, typically named xxx.fi where xxx is

    the name of the project. If '-' is given, standard output is used.

    Darcs 2.2 or later must be installed as various subcommands are

    used to access the source repository. The source may be a network

    URL but using a local URL is recommended for performance reasons.

    """