~zindar/bzr-extmerge/trunk

# -*- coding: UTF-8 -*-

# Copyright (C) 2006 Erik Bågfors <erik@bagfors.nu>

#

# GNU GPL v2.

#

"""external merge plugin for bzr"""

import errno

import exceptions

import os

import shutil

from subprocess import call

import tempfile

from bzrlib.commands import Command, register_command

from bzrlib.config import GlobalConfig

from bzrlib.conflicts import CONFLICT_SUFFIXES

from bzrlib.errors import BzrCommandError

from bzrlib.option import Option

from bzrlib.workingtree import WorkingTree

# The same syntax as in mergetools below, can be used in external_merge

# in bazaar.conf

# %b = base  (foo.BASE)

# %t = this  (foo.THIS)

# %o = other (foo.OTHER)

# %r = resolved file (aka output file) (foo)

# %T = this  (foo.THIS), a temporary copy of foo.THIS; will be used to

#                        overwrite 'foo' if the merge succeeds

valid_parameter_sets = (

    # normal 3 way merge + output file

    ('%r', '%b', '%t', '%o'),

    # meld-style 3 way merge, one file (%T) being used for both in- and output

    ('%b', '%T', '%o'),

    # meld-style 2 way merge, one file (%T) being used for both in- and output

    ('%T', '%o')

)

mergetools = [

    'kdiff3 --output %r %b %t %o',

    'xxdiff -m -O -M %r %t %b %o',

    'meld %b %T %o',

    'opendiff %t %o -ancestor %b -merge %r'

]

class cmd_extmerge(Command):

    """Calls an external merge program such as meld, xxdiff, kdiff3, opendiff, etc

    to help you resolve any conflicts you have.

    Will call a user defined merge tool if it exists, otherwise, will try

    kdiff3, xxdiff, meld and opendiff, in that order.

    To define your own merge tool, set external_merge in bazaar.conf.

    See extmerge/__init__.py for the syntax.

    """

    aliases = ['emerge']

    takes_args = ['file*']

    takes_options = [Option('all', help='Use all files with conflicts.')]

    def run(self, file_list, all=False):

        if file_list is None:

            if not all:

                raise BzrCommandError(

                    "command 'extmerge' needs one or more FILE, or --all")

            tree = WorkingTree.open_containing(u'.')[0]

            file_list = list(tree.abspath(f.path) for f in tree.conflicts())

        else:

            if all:

                raise BzrCommandError(

                        "If --all is specified, no FILE may be provided")

        for filename in file_list:

            if not os.path.exists(filename):

                print "%s does not exists" % filename

            else:

                failures = 0

                for suffix in CONFLICT_SUFFIXES:

                    if not os.path.exists(filename + suffix) and not failures:

                        print "%s is not conflicted" % filename

                        failures = 1

                if not failures:

                    run_extmerge(filename)

        if len(file_list) == 0:

            print "no conflicting files"

        else:

            print "remember to bzr resolve your files"

def get_user_merge_tool():

    return GlobalConfig().get_user_option('external_merge')

def validate_command(tool):

    """Validates that 'tool' contains at least one set of 'valid_parameter_sets'"""

    def check_substrings(string, substrings):

        """Checks if all 'substrings' occur in 'string'"""

        for e in substrings:

            if not e in string:

                return False

        return True

    sets = map(lambda x: check_substrings(tool, x), valid_parameter_sets)

    # not a single valid-parameter-set present -> BzrCommandError

    if not True in sets:

        raise BzrCommandError(

            "Error in external merge tool definition.\n" +

            "Definition needs to contain one of the following parameter sets:\n" +

            "".join(map(

                lambda x:

                    "\t- %s\n" % x,

                    map(", ".join, valid_parameter_sets)

            )) +

            "Definition is %s" % tool

        )

def execute_command(tool, filename):

    tool = tool.replace('%r', filename)

    tool = tool.replace('%t', filename + '.THIS')

    tool = tool.replace('%o', filename + '.OTHER')

    tool = tool.replace('%b', filename + '.BASE')

    # create tmpfile for %T (if needed)

    this_tmp = False

    if '%T' in tool:

        this_tmp = tempfile.mktemp("_bzr_extmerge_%s.THIS" % os.path.basename(filename))

        shutil.copy(filename + ".THIS", this_tmp)

        tool = tool.replace('%T', this_tmp)

    ret = call(tool.split(' '))

    # cleanup tmpfile of %T

    if this_tmp:

        # merge success -> keep changes

        if ret == 0:

            shutil.move(this_tmp, filename)

        # merge failed -> delete file

        else:

            os.remove(this_tmp)

    return ret

def run_extmerge(filename):

    global mergetools

    usertool = get_user_merge_tool()

    if usertool:

        mergetools = [usertool]

    for tool in mergetools:

        validate_command(tool)

        try:

            ret = execute_command(tool, filename)

        except OSError, e:

            # ENOENT means no such editor

            if e.errno == errno.ENOENT:

                continue

            raise

        if ret == 0:

            return True

        elif ret == 127:

            continue

        else:

            mergetools = [tool]

            break

    if len(mergetools) != 1:

        raise BzrCommandError("Found no valid merge tool")

register_command(cmd_extmerge)