/brz/remove-bazaar

# Copyright (C) 2007 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

"""The model for interacting with the git process, etc."""

import os

import subprocess

from bzrlib.plugins.git import errors

class GitModel(object):

    """API that follows GIT model closely"""

    def __init__(self, git_dir):

        self.git_dir = git_dir

    def git_command(self, command, args):

        return ['git', command] + args

    def git_lines(self, command, args):

        cmd = self.git_command(command, args)

        env = os.environ.copy()

        env['GIT_DIR'] = self.git_dir

        p = subprocess.Popen(cmd,

                             stdout=subprocess.PIPE,

                             stderr=subprocess.PIPE,

                             env=env)

        lines = p.stdout.readlines()

        if p.wait() != 0:

            raise errors.GitCommandError(cmd, p.returncode,

                                         p.stderr.read().strip())

        return lines

    def git_line(self, command, args):

        lines = self.git_lines(command, args)

        return lines[0]

    def cat_file(self, type, object_id, pretty=False):

        args = []

        if pretty:

            args.append('-p')

        else:

            args.append(type)

        args.append(object_id)

        return self.git_lines('cat-file', args)

    def rev_list(self, heads, max_count=None, header=False, parents=False):

        args = []

        if max_count is not None:

            args.append('--max-count=%d' % max_count)

        if header:

            args.append('--header')

        if parents:

            args.append('--parents')

        if heads is None:

            args.append('--all')

        else:

            args.extend(heads)

        return self.git_lines('rev-list', args)

    def rev_parse(self, git_id):

        args = ['--verify', git_id]

        return self.git_line('rev-parse', args).strip()

    def get_head(self):

        try:

            return self.rev_parse('HEAD')

        except errors.GitCommandError, e:

            # Most likely, this is a null branch, so treat it as such

            if e.stderr == 'fatal: Needed a single revision':

                return None

            raise

    def ancestry(self, revisions):

        ancestors = {}

        for line in self.rev_list(revisions, parents=True):

            entries = line.split()

            ancestors[entries[0]] = entries[1:]

        return ancestors

    def ancestor_lines(self, revisions):

        revision_lines = []

        for line in self.rev_list(revisions, header=True):

            if line.startswith('\x00'):

                yield revision_lines

                revision_lines = [line[1:].decode('latin-1')]

            else:

                revision_lines.append(line.decode('latin-1'))

        assert revision_lines == ['']

    def get_inventory(self, tree_id):

        for line in self.git_lines('ls-tree', ['-r', '-t', tree_id]):

            # Ideally, we would use -z so we would not have to handle escaped

            # file names. But then we could not use readlines() to split the

            # data as it is read.

            permissions, type, hash_and_path = line.split(' ', 2)

            hash, name = hash_and_path.split('\t', 1)

            name = name[:-1] # strip trailing newline

            if name.startswith('"'):

                name = name[1:-1].decode('string_escape')

            name = name.decode('utf-8')

            yield permissions, type, hash, name