RE: [PATCH v1] Remove no-op revisions

#! /usr/bin/python

# (Be in -*- python -*- mode.)
#
# ====================================================================
# Copyright (C) 2010 Cabot Communications Ltd.  All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution.  The terms
# are also available at http://subversion.tigris.org/license-1.html.
# If newer versions of this license are posted there, you may use a
# newer version instead, at your option.
#
# This software consists of voluntary contributions made by many
# individuals.  For exact contribution history, see the revision
# history and logs, available at http://cvs2svn.tigris.org/.
# ====================================================================
#
#
# Usage: renumber_branch.py OLDREVNUM NEWREVNUM PATH...
#
# WARNING: This modifies RCS files in-place.  Make sure you only run
#          it on a _copy_ of your repository.  And have backups.
#
# Modify RCS files in PATH to renumber a revision and/or branch.
#
# Will also renumber any revisions on the branch and any branches from
# a renumbered revision.  E.g. if you ask to renumber branch 1.3.5
# to 1.3.99, it will also renumber revision 1.3.5.1 to 1.3.99.1, and
# renumber branch 1.3.5.1.7 to 1.3.99.1.7.  This is usually what you
# want.
#
# Originally written to correct a non-standard vendor branch number,
# by renumbering the 1.1.2 branch to 1.1.1.  This allows cvs2svn to
# detect that it's a vendor branch.
#
# This doesn't enforce all the rules about revision numbers.  It is
# possible to make invalid repositories using this tool.
#
# This does try to detect if the specified revision number is already
# in use, and fail in that case.
#

import sys
import os

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0]))))

import cvs2svn_rcsparse
from rcs_file_filter import WriteRCSFileSink, FilterSink

class RenumberingFilter(FilterSink):
    '''A filter that transforms all revision numbers using a
    function provided to the constructor.'''

    def __init__(self, sink, transform_revision_func):
        '''Constructor.

        SINK is the object we're wrapping.  It must implement the
             cvs2svn_rcsparse.Sink interface.
        TRANSFORM_REVISION_FUNC is a function that takes a single
             CVS revision number, as a string, and returns the
             possibly-transformed revision number in the same format.
        '''
        FilterSink.__init__(self, sink)
        self.transform_rev = transform_revision_func

    def set_head_revision(self, revision):
        FilterSink.set_head_revision(self, self.transform_rev(revision))

    def set_principal_branch(self, branch_name):
        FilterSink.set_principal_branch(self, self.transform_rev(branch_name))

    def define_tag(self, name, revision):
        FilterSink.define_tag(self, name, self.transform_rev(revision))

    def define_revision(
            self, revision, timestamp, author, state, branches, next
            ):
        revision = self.transform_rev(revision)
        branches = [self.transform_rev(b) for b in branches]
        if next is not None:
            next = self.transform_rev(next)
        FilterSink.define_revision(
            self, revision, timestamp, author, state, branches, next
            )

    def set_revision_info(self, revision, log, text):
        FilterSink.set_revision_info(self, self.transform_rev(revision),
                                     log, text)


def get_transform_func(rev_from, rev_to, force):
    rev_from_z = '%s.0.%s' % tuple(rev_from.rsplit('.', 1))
    rev_to_z = '%s.0.%s' % tuple(rev_to.rsplit('.', 1))
    def transform_revision(revision):
        if revision == rev_from or revision.startswith(rev_from + '.'):
            revision = rev_to + revision[len(rev_from):]
        elif revision == rev_from_z:
            revision = rev_to_z
        elif not force and (revision == rev_to or revision == rev_to_z
                or revision.startswith(rev_to + '.')):
            raise Exception('Target branch already exists')
        return revision
    return transform_revision

def process_file(filename, rev_from, rev_to, force):
    func = get_transform_func(rev_from, rev_to, force)
    tmp_filename = filename + '.tmp'
    infp = open(filename, 'rb')
    outfp = open(tmp_filename, 'wb')
    try:
        writer = WriteRCSFileSink(outfp)
        revfilter = RenumberingFilter(writer, func)
        cvs2svn_rcsparse.parse(infp, revfilter)
    finally:
        outfp.close()
        infp.close()
    os.rename(tmp_filename, filename)

def iter_files_in_dir(top_path):
    for (dirpath, dirnames, filenames) in os.walk(top_path):
        for name in filenames:
            yield os.path.join(dirpath, name)

def iter_rcs_files(list_of_starting_paths, verbose=False):
    for base_path in list_of_starting_paths:
        if os.path.isfile(base_path) and base_path.endswith(',v'):
            yield base_path
        elif os.path.isdir(base_path):
            for file_path in iter_files_in_dir(base_path):
                if file_path.endswith(',v'):
                    yield file_path
                elif verbose:
                    sys.stdout.write('File %s is being ignored.\n' % file_path)
        elif verbose:
            sys.stdout.write('PATH %s is being ignored.\n' % base_path)

def main():
    if len(sys.argv) < 4 or '.' not in sys.argv[1] or '.' not in sys.argv[2]:
        sys.stderr.write('Usage: %s OLDREVNUM NEWREVNUM PATH...\n' % (sys.argv[0],))
        sys.exit(1)

    rev_from = sys.argv[1]
    rev_to = sys.argv[2]
    force = False
    for path in iter_rcs_files(sys.argv[3:], verbose=True):
        sys.stdout.write('Processing %s...' % path)
        process_file(path, rev_from, rev_to, force)
        sys.stdout.write('done.\n')

if __name__ == '__main__':
    main()