~bzr-pqm/bzr/bzr.dev

from bzrlib.merge_core import merge_flex, ApplyMerge3, BackupBeforeChange

from bzrlib.changeset import generate_changeset, ExceptionConflictHandler

from bzrlib.changeset import Inventory, Diff3Merge

from bzrlib import find_branch

import bzrlib.osutils

from bzrlib.errors import BzrCommandError

from bzrlib.delta import compare_trees

from trace import mutter, warning

import os.path

import tempfile

import shutil

import errno

# comments from abentley on irc: merge happens in two stages, each

# of which generates a changeset object

# stage 1: generate OLD->OTHER,

# stage 2: use MINE and OLD->OTHER to generate MINE -> RESULT

class UnrelatedBranches(BzrCommandError):

    def __init__(self):

        msg = "Branches have no common ancestor, and no base revision"\

            " specified."

        BzrCommandError.__init__(self, msg)

class MergeConflictHandler(ExceptionConflictHandler):

    """Handle conflicts encountered while merging.

    This subclasses ExceptionConflictHandler, so that any types of

    conflict that are not explicitly handled cause an exception and

    terminate the merge.

    """

    def __init__(self, dir, ignore_zero=False):

        ExceptionConflictHandler.__init__(self, dir)

        self.conflicts = 0

        self.ignore_zero = ignore_zero

    def copy(self, source, dest):

        """Copy the text and mode of a file

        :param source: The path of the file to copy

        :param dest: The distination file to create

        """

        s_file = file(source, "rb")

        d_file = file(dest, "wb")

        for line in s_file:

            d_file.write(line)

        os.chmod(dest, 0777 & os.stat(source).st_mode)

    def add_suffix(self, name, suffix, last_new_name=None):

        """Rename a file to append a suffix.  If the new name exists, the

        suffix is added repeatedly until a non-existant name is found

        :param name: The path of the file

        :param suffix: The suffix to append

        :param last_new_name: (used for recursive calls) the last name tried

        """

        if last_new_name is None:

            last_new_name = name

        new_name = last_new_name+suffix

        try:

            os.rename(name, new_name)

            return new_name

        except OSError, e:

            if e.errno != errno.EEXIST and e.errno != errno.ENOTEMPTY:

                raise

            return self.add_suffix(name, suffix, last_new_name=new_name)

    def conflict(self, text):

        warning(text)

        self.conflicts += 1

    def merge_conflict(self, new_file, this_path, base_path, other_path):

        """

        Handle diff3 conflicts by producing a .THIS, .BASE and .OTHER.  The

        main file will be a version with diff3 conflicts.

        :param new_file: Path to the output file with diff3 markers

        :param this_path: Path to the file text for the THIS tree

        :param base_path: Path to the file text for the BASE tree

        :param other_path: Path to the file text for the OTHER tree

        """

        self.add_suffix(this_path, ".THIS")

        self.copy(base_path, this_path+".BASE")

        self.copy(other_path, this_path+".OTHER")

        os.rename(new_file, this_path)

        self.conflict("Diff3 conflict encountered in %s" % this_path)

    def new_contents_conflict(self, filename, other_contents):

        """Conflicting contents for newly added file."""

        self.copy(other_contents, filename + ".OTHER")

        self.conflict("Conflict in newly added file %s" % filename)

    def target_exists(self, entry, target, old_path):

        """Handle the case when the target file or dir exists"""

        moved_path = self.add_suffix(target, ".moved")

        self.conflict("Moved existing %s to %s" % (target, moved_path))

    def rmdir_non_empty(self, filename):

        """Handle the case where the dir to be removed still has contents"""

        self.conflict("Directory %s not removed because it is not empty"\

            % filename)

        return "skip"

    def finalize(self):

        if not self.ignore_zero:

            print "%d conflicts encountered.\n" % self.conflicts

class SourceFile(object):

    def __init__(self, path, id, present=None, isdir=None):

        self.path = path

        self.id = id

        self.present = present

        self.isdir = isdir

        self.interesting = True

    def __repr__(self):

        return "SourceFile(%s, %s)" % (self.path, self.id)

def get_tree(treespec, temp_root, label):

    location, revno = treespec

    branch = find_branch(location)

    if revno is None:

        base_tree = branch.working_tree()

    elif revno == -1:

        base_tree = branch.basis_tree()

    else:

        base_tree = branch.revision_tree(branch.lookup_revision(revno))

    temp_path = os.path.join(temp_root, label)

    os.mkdir(temp_path)

    return branch, MergeTree(base_tree, temp_path)

def abspath(tree, file_id):

    path = tree.inventory.id2path(file_id)

    if path == "":

        return "./."

    return "./" + path

def file_exists(tree, file_id):

    return tree.has_filename(tree.id2path(file_id))

def inventory_map(tree):

    inventory = {}

    for file_id in tree.inventory:

        path = abspath(tree, file_id)

        inventory[path] = SourceFile(path, file_id)

    return inventory

class MergeTree(object):

    def __init__(self, tree, tempdir):

        object.__init__(self)

        if hasattr(tree, "basedir"):

            self.root = tree.basedir

        else:

            self.root = None

        self.inventory = inventory_map(tree)

        self.tree = tree

        self.tempdir = tempdir

        os.mkdir(os.path.join(self.tempdir, "texts"))

        self.cached = {}

    def __contains__(self, file_id):

        return id in self.tree

    def get_file_sha1(self, id):

        return self.tree.get_file_sha1(id)

    def readonly_path(self, id):

        if id not in self.tree:

            return None

        if self.root is not None:

            return self.tree.abspath(self.tree.id2path(id))

        else:

            if self.tree.inventory[id].kind in ("directory", "root_directory"):

                return self.tempdir

            if not self.cached.has_key(id):

                path = os.path.join(self.tempdir, "texts", id)

                outfile = file(path, "wb")

                outfile.write(self.tree.get_file(id).read())

                assert(os.path.exists(path))

                self.cached[id] = path

            return self.cached[id]

def merge(other_revision, base_revision,

          check_clean=True, ignore_zero=False,

          this_dir=None, backup_files=False, merge_type=ApplyMerge3,

          file_list=None):

    """Merge changes into a tree.

    base_revision

        Base for three-way merge.

    other_revision

        Other revision for three-way merge.

    this_dir

        Directory to merge changes into; '.' by default.

    check_clean

        If true, this_dir must have no uncommitted changes before the

        merge begins.

    """

    tempdir = tempfile.mkdtemp(prefix="bzr-")

    try:

        if this_dir is None:

            this_dir = '.'

        this_branch = find_branch(this_dir)

        if check_clean:

            changes = compare_trees(this_branch.working_tree(), 

                                    this_branch.basis_tree(), False)

            if changes.has_changed():

                raise BzrCommandError("Working tree has uncommitted changes.")

        other_branch, other_tree = get_tree(other_revision, tempdir, "other")

        if base_revision == [None, None]:

            if other_revision[1] == -1:

                o_revno = None

            else:

                o_revno = other_revision[1]

            base_revno = this_branch.common_ancestor(other_branch, 

                                                     other_revno=o_revno)[0]

            if base_revno is None:

                raise UnrelatedBranches()

            base_revision = ['.', base_revno]

        base_branch, base_tree = get_tree(base_revision, tempdir, "base")

        if file_list is None:

            interesting_ids = None

        else:

            interesting_ids = set()

            this_tree = this_branch.working_tree()

            for fname in file_list:

                path = this_branch.relpath(fname)

                found_id = False

                for tree in (this_tree, base_tree.tree, other_tree.tree):

                    file_id = tree.inventory.path2id(path)

                    if file_id is not None:

                        interesting_ids.add(file_id)

                        found_id = True

                if not found_id:

                    raise BzrCommandError("%s is not a source file in any"

                                          " tree." % fname)

        merge_inner(this_branch, other_tree, base_tree, tempdir, 

                    ignore_zero=ignore_zero, backup_files=backup_files, 

                    merge_type=merge_type, interesting_ids=interesting_ids)

    finally:

        shutil.rmtree(tempdir)

def set_interesting(inventory_a, inventory_b, interesting_ids):

    """Mark files whose ids are in interesting_ids as interesting

    """

    for inventory in (inventory_a, inventory_b):

        for path, source_file in inventory.iteritems():

             source_file.interesting = source_file.id in interesting_ids

def generate_cset_optimized(tree_a, tree_b, inventory_a, inventory_b,

                            interesting_ids=None):

    """Generate a changeset.  If interesting_ids is supplied, only changes

    to those files will be shown.  Metadata changes are stripped.

    """ 

    if interesting_ids is not None:

        set_interesting(inventory_a, inventory_b, interesting_ids)

    cset =  generate_changeset(tree_a, tree_b, inventory_a, inventory_b)

    for entry in cset.entries.itervalues():

        entry.metadata_change = None

    return cset

def merge_inner(this_branch, other_tree, base_tree, tempdir, 

                ignore_zero=False, merge_type=ApplyMerge3, backup_files=False,

                interesting_ids=None):

    def merge_factory(base_file, other_file):

        contents_change = merge_type(base_file, other_file)

        if backup_files:

            contents_change = BackupBeforeChange(contents_change)

        return contents_change

    def generate_cset(tree_a, tree_b, inventory_a, inventory_b):

        return generate_cset_optimized(tree_a, tree_b, inventory_a, inventory_b,

                                       interesting_ids)

    this_tree = get_tree((this_branch.base, None), tempdir, "this")[1]

    def get_inventory(tree):

        return tree.inventory

    inv_changes = merge_flex(this_tree, base_tree, other_tree,

                             generate_cset, get_inventory,

                             MergeConflictHandler(base_tree.root,

                                                  ignore_zero=ignore_zero),

                             merge_factory=merge_factory)

    adjust_ids = []

    for id, path in inv_changes.iteritems():

        if path is not None:

            if path == '.':

                path = ''

            else:

                assert path.startswith('./')

            path = path[2:]

        adjust_ids.append((path, id))

    if len(adjust_ids) > 0:

        this_branch.set_inventory(regen_inventory(this_branch, this_tree.root,

                                                  adjust_ids))

def regen_inventory(this_branch, root, new_entries):

    old_entries = this_branch.read_working_inventory()

    new_inventory = {}

    by_path = {}

    for file_id in old_entries:

        entry = old_entries[file_id]

        path = old_entries.id2path(file_id)

        new_inventory[file_id] = (path, file_id, entry.parent_id, entry.kind)

        by_path[path] = file_id

    deletions = 0

    insertions = 0

    new_path_list = []

    for path, file_id in new_entries:

        if path is None:

            del new_inventory[file_id]

            deletions += 1

        else:

            new_path_list.append((path, file_id))

            if file_id not in old_entries:

                insertions += 1

    # Ensure no file is added before its parent

    new_path_list.sort()

    for path, file_id in new_path_list:

        if path == '':

            parent = None

        else:

            parent = by_path[os.path.dirname(path)]

        kind = bzrlib.osutils.file_kind(os.path.join(root, path))

        new_inventory[file_id] = (path, file_id, parent, kind)

        by_path[path] = file_id 

    # Get a list in insertion order

    new_inventory_list = new_inventory.values()

    mutter ("""Inventory regeneration:

old length: %i insertions: %i deletions: %i new_length: %i"""\

        % (len(old_entries), insertions, deletions, len(new_inventory_list)))

    assert len(new_inventory_list) == len(old_entries) + insertions - deletions

    new_inventory_list.sort()

    return new_inventory_list

merge_types = {     "merge3": (ApplyMerge3, "Native diff3-style merge"), 

                     "diff3": (Diff3Merge,  "Merge using external diff3")

              }