~bzr-pqm/bzr/bzr.dev

import changeset

from changeset import Inventory, apply_changeset, invert_dict

import os.path

from osutils import backup_file

from merge3 import Merge3

class ApplyMerge3:

    """Contents-change wrapper around merge3.Merge3"""

    def __init__(self, file_id, base, other):

        self.file_id = file_id

        self.base = base

        self.other = other

    def __eq__(self, other):

        if not isinstance(other, ApplyMerge3):

            return False

        return (self.base == other.base and 

                self.other == other.other and self.file_id == other.file_id)

    def __ne__(self, other):

        return not (self == other)

    def apply(self, filename, conflict_handler, reverse=False):

        new_file = filename+".new" 

        if not reverse:

            base = self.base

            other = self.other

        else:

            base = self.other

            other = self.base

        def get_lines(tree):

            if self.file_id not in tree:

                raise Exception("%s not in tree" % self.file_id)

                return ()

            return tree.get_file(self.file_id).readlines()

        base_lines = get_lines(base)

        other_lines = get_lines(other)

        m3 = Merge3(base_lines, file(filename, "rb").readlines(), other_lines)

        new_conflicts = False

        output_file = file(new_file, "wb")

        start_marker = "!START OF MERGE CONFLICT!" + "I HOPE THIS IS UNIQUE"

        for line in m3.merge_lines(name_a = "TREE", name_b = "MERGE-SOURCE", 

                       start_marker=start_marker):

            if line.startswith(start_marker):

                new_conflicts = True

                output_file.write(line.replace(start_marker, '<' * 7))

            else:

                output_file.write(line)

        output_file.close()

        if not new_conflicts:

            os.chmod(new_file, os.stat(filename).st_mode)

            os.rename(new_file, filename)

            return

        else:

            conflict_handler.merge_conflict(new_file, filename, base_lines,

                                            other_lines)

class BackupBeforeChange:

    """Contents-change wrapper to back up file first"""

    def __init__(self, contents_change):

        self.contents_change = contents_change

    def __eq__(self, other):

        if not isinstance(other, BackupBeforeChange):

            return False

        return (self.contents_change == other.contents_change)

    def __ne__(self, other):

        return not (self == other)

    def apply(self, filename, conflict_handler, reverse=False):

        backup_file(filename)

        self.contents_change.apply(filename, conflict_handler, reverse)

def invert_invent(inventory):

    invert_invent = {}

    for file_id in inventory:

        path = inventory.id2path(file_id)

        if path == '':

            path = './.'

        else:

            path = './' + path

        invert_invent[file_id] = path

    return invert_invent

def merge_flex(this, base, other, changeset_function, inventory_function,

               conflict_handler, merge_factory, interesting_ids):

    cset = changeset_function(base, other, interesting_ids)

    new_cset = make_merge_changeset(cset, this, base, other, 

                                    conflict_handler, merge_factory)

    result = apply_changeset(new_cset, invert_invent(this.tree.inventory),

                             this.root, conflict_handler, False)

    conflict_handler.finalize()

    return result

def make_merge_changeset(cset, this, base, other, 

                         conflict_handler, merge_factory):

    new_cset = changeset.Changeset()

    def get_this_contents(id):

        path = this.readonly_path(id)

        if os.path.isdir(path):

            return changeset.dir_create

        else:

            return changeset.FileCreate(file(path, "rb").read())

    for entry in cset.entries.itervalues():

        if entry.is_boring():

            new_cset.add_entry(entry)

        else:

            new_entry = make_merged_entry(entry, this, base, other, 

                                          conflict_handler)

            new_contents = make_merged_contents(entry, this, base, other, 

                                                conflict_handler,

                                                merge_factory)

            new_entry.contents_change = new_contents

            new_entry.metadata_change = make_merged_metadata(entry, base, other)

            new_cset.add_entry(new_entry)

    return new_cset

class ThreeWayConflict(Exception):

    def __init__(self, this, base, other):

        self.this = this

        self.base = base

        self.other = other

        msg = "Conflict merging %s %s and %s" % (this, base, other)

        Exception.__init__(self, msg)

def threeway_select(this, base, other):

    """Returns a value selected by the three-way algorithm.

    Raises ThreewayConflict if the algorithm yields a conflict"""

    if base == other:

        return this

    elif base == this:

        return other

    elif other == this:

        return this

    else:

        raise ThreeWayConflict(this, base, other)

def make_merged_entry(entry, this, base, other, conflict_handler):

    from bzrlib.trace import mutter

    def entry_data(file_id, tree):

        assert hasattr(tree, "__contains__"), "%s" % tree

        if not tree.has_or_had_id(file_id):

            return (None, None, "")

        entry = tree.tree.inventory[file_id]

        my_dir = tree.id2path(entry.parent_id)

        if my_dir is None:

            my_dir = ""

        return entry.name, entry.parent_id, my_dir 

    this_name, this_parent, this_dir = entry_data(entry.id, this)

    base_name, base_parent, base_dir = entry_data(entry.id, base)

    other_name, other_parent, other_dir = entry_data(entry.id, other)

    mutter("Dirs: this, base, other %r %r %r" % (this_dir, base_dir, other_dir))

    mutter("Names: this, base, other %r %r %r" % (this_name, base_name, other_name))

    old_name = this_name

    try:

        new_name = threeway_select(this_name, base_name, other_name)

    except ThreeWayConflict:

        new_name = conflict_handler.rename_conflict(entry.id, this_name, 

                                                    base_name, other_name)

    old_parent = this_parent

    try:

        new_parent = threeway_select(this_parent, base_parent, other_parent)

    except ThreeWayConflict:

        new_parent = conflict_handler.move_conflict(entry.id, this_dir,

                                                    base_dir, other_dir)

    def get_path(name, parent):

        if name is not None:

            if name == "":

                assert parent is None

                return './.'

            parent_dir = {this_parent: this_dir, other_parent: other_dir, 

                          base_parent: base_dir}

            directory = parent_dir[parent]

            return os.path.join(directory, name)

        else:

            assert parent is None

            return None

    old_path = get_path(old_name, old_parent)

    new_entry = changeset.ChangesetEntry(entry.id, old_parent, old_path)

    new_entry.new_path = get_path(new_name, new_parent)

    new_entry.new_parent = new_parent

    mutter(repr(new_entry))

    return new_entry

def get_contents(entry, tree):

    """Get a contents change element suitable for use with ReplaceContents

    """

    tree_entry = tree.tree.inventory[entry.id]

    if tree_entry.kind == "file":

        return changeset.FileCreate(tree.get_file(entry.id).read())

    else:

        assert tree_entry.kind in ("root_directory", "directory")

        return changeset.dir_create

def make_merged_contents(entry, this, base, other, conflict_handler,

                         merge_factory):

    contents = entry.contents_change

    if contents is None:

        return None

    this_path = this.readonly_path(entry.id)

    def make_merge():

        if this_path is None:

            return conflict_handler.missing_for_merge(entry.id, 

                                                      other.id2path(entry.id))

        return merge_factory(entry.id, base, other)

    if isinstance(contents, changeset.ReplaceContents):

        if contents.old_contents is None and contents.new_contents is None:

            return None

        if contents.new_contents is None:

            if this_path is not None and os.path.exists(this_path):

                return contents

            else:

                return None

        elif contents.old_contents is None:

            if this_path is None or not os.path.exists(this_path):

                return contents

            else:

                this_contents = get_contents(entry, this)

                if this_contents == contents.new_contents:

                    return None

                else:

                    other_path = other.readonly_path(entry.id)    

                    conflict_handler.new_contents_conflict(this_path, 

                                                           other_path)

        elif isinstance(contents.old_contents, changeset.FileCreate) and \

            isinstance(contents.new_contents, changeset.FileCreate):

            return make_merge()

        else:

            raise Exception("Unhandled merge scenario")

def make_merged_metadata(entry, base, other):

    if entry.metadata_change is not None:

        base_path = base.readonly_path(entry.id)

        other_path = other.readonly_path(entry.id)    

        return PermissionsMerge(base_path, other_path)

class PermissionsMerge(object):

    def __init__(self, base_path, other_path):

        self.base_path = base_path

        self.other_path = other_path

    def apply(self, filename, conflict_handler, reverse=False):

        if not reverse:

            base = self.base_path

            other = self.other_path

        else:

            base = self.other_path

            other = self.base_path

        base_stat = os.stat(base).st_mode

        other_stat = os.stat(other).st_mode

        this_stat = os.stat(filename).st_mode

        if base_stat &0777 == other_stat &0777:

            return

        elif this_stat &0777 == other_stat &0777:

            return

        elif this_stat &0777 == base_stat &0777:

            os.chmod(filename, other_stat)

        else:

            conflict_handler.permission_conflict(filename, base, other)