~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2010 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Utility functions for managing external merge tools such as kdiff3."""

from __future__ import absolute_import

import os

import shutil

import subprocess

import sys

import tempfile

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

from bzrlib import (

    cmdline,

    osutils,

    trace,

)

""")

known_merge_tools = {

    'bcompare': 'bcompare {this} {other} {base} {result}',

    'kdiff3': 'kdiff3 {base} {this} {other} -o {result}',

    'xdiff': 'xxdiff -m -O -M {result} {this} {base} {other}',

    'meld': 'meld {base} {this_temp} {other}',

    'opendiff': 'opendiff {this} {other} -ancestor {base} -merge {result}',

    'winmergeu': 'winmergeu {result}',

}

def check_availability(command_line):

    cmd_list = cmdline.split(command_line)

    exe = cmd_list[0]

    if sys.platform == 'win32':

        exe = _get_executable_path(exe)

        if exe is None:

            return False

        base, ext = os.path.splitext(exe)

        path_ext = [unicode(s.lower())

                    for s in os.getenv('PATHEXT', '').split(os.pathsep)]

        return os.path.exists(exe) and ext in path_ext

    else:

        return (os.access(exe, os.X_OK)

                or osutils.find_executable_on_path(exe) is not None)

def invoke(command_line, filename, invoker=None):

    """Invokes the given merge tool command line, substituting the given

    filename according to the embedded substitution markers. Optionally, it

    will use the given invoker function instead of the default

    subprocess_invoker.

    """

    if invoker is None:

        invoker = subprocess_invoker

    cmd_list = cmdline.split(command_line)

    exe = _get_executable_path(cmd_list[0])

    if exe is not None:

        cmd_list[0] = exe

    args, tmp_file = _subst_filename(cmd_list, filename)

    def cleanup(retcode):

        if tmp_file is not None:

            if retcode == 0: # on success, replace file with temp file

                shutil.move(tmp_file, filename)

            else: # otherwise, delete temp file

                os.remove(tmp_file)

    return invoker(args[0], args[1:], cleanup)

def _get_executable_path(exe):

    if os.path.isabs(exe):

        return exe

    return osutils.find_executable_on_path(exe)

def _subst_filename(args, filename):

    subst_names = {

        'base': filename + u'.BASE',

        'this': filename + u'.THIS',

        'other': filename + u'.OTHER',

        'result': filename,

    }

    tmp_file = None

    subst_args = []

    for arg in args:

        if '{this_temp}' in arg and not 'this_temp' in subst_names:

            fh, tmp_file = tempfile.mkstemp(u"_bzr_mergetools_%s.THIS" %

                                            os.path.basename(filename))

            trace.mutter('fh=%r, tmp_file=%r', fh, tmp_file)

            os.close(fh)

            shutil.copy(filename + u".THIS", tmp_file)

            subst_names['this_temp'] = tmp_file

        arg = _format_arg(arg, subst_names)

        subst_args.append(arg)

    return subst_args, tmp_file

# This would be better implemented using format() from python 2.6

def _format_arg(arg, subst_names):

    arg = arg.replace('{base}', subst_names['base'])

    arg = arg.replace('{this}', subst_names['this'])

    arg = arg.replace('{other}', subst_names['other'])

    arg = arg.replace('{result}', subst_names['result'])

    if subst_names.has_key('this_temp'):

        arg = arg.replace('{this_temp}', subst_names['this_temp'])

    return arg

def subprocess_invoker(executable, args, cleanup):

    retcode = subprocess.call([executable] + args)

    cleanup(retcode)

    return retcode