~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 Canonical

# 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

from bzrlib.inventory import InventoryEntry

from bzrlib.trace import mutter

from bzrlib import tree

class TreeDelta(object):

    """Describes changes from one tree to another.

    Contains four lists:

    added

        (path, id, kind)

    removed

        (path, id, kind)

    renamed

        (oldpath, newpath, id, kind, text_modified, meta_modified)

    modified

        (path, id, kind, text_modified, meta_modified)

    unchanged

        (path, id, kind)

    Each id is listed only once.

    Files that are both modified and renamed are listed only in

    renamed, with the text_modified flag true. The text_modified

    applies either to the the content of the file or the target of the

    symbolic link, depending of the kind of file.

    Files are only considered renamed if their name has changed or

    their parent directory has changed.  Renaming a directory

    does not count as renaming all its contents.

    The lists are normally sorted when the delta is created.

    """

    def __init__(self):

        self.added = []

        self.removed = []

        self.renamed = []

        self.modified = []

        self.unchanged = []

    def __eq__(self, other):

        if not isinstance(other, TreeDelta):

            return False

        return self.added == other.added \

               and self.removed == other.removed \

               and self.renamed == other.renamed \

               and self.modified == other.modified \

               and self.unchanged == other.unchanged

    def __ne__(self, other):

        return not (self == other)

    def __repr__(self):

        return "TreeDelta(added=%r, removed=%r, renamed=%r, modified=%r," \

            " unchanged=%r)" % (self.added, self.removed, self.renamed,

            self.modified, self.unchanged)

    def has_changed(self):

        return bool(self.modified

                    or self.added

                    or self.removed

                    or self.renamed)

    def touches_file_id(self, file_id):

        """Return True if file_id is modified by this delta."""

        for l in self.added, self.removed, self.modified:

            for v in l:

                if v[1] == file_id:

                    return True

        for v in self.renamed:

            if v[2] == file_id:

                return True

        return False

    def show(self, to_file, show_ids=False, show_unchanged=False):

        """output this delta in status-like form to to_file."""

        def show_list(files):

            for item in files:

                path, fid, kind = item[:3]

                if kind == 'directory':

                    path += '/'

                elif kind == 'symlink':

                    path += '@'

                if len(item) == 5 and item[4]:

                    path += '*'

                if show_ids:

                    print >>to_file, '  %-30s %s' % (path, fid)

                else:

                    print >>to_file, ' ', path

        if self.removed:

            print >>to_file, 'removed:'

            show_list(self.removed)

        if self.added:

            print >>to_file, 'added:'

            show_list(self.added)

        extra_modified = []

        if self.renamed:

            print >>to_file, 'renamed:'

            for (oldpath, newpath, fid, kind,

                 text_modified, meta_modified) in self.renamed:

                if text_modified or meta_modified:

                    extra_modified.append((newpath, fid, kind,

                                           text_modified, meta_modified))

                if meta_modified:

                    newpath += '*'

                if show_ids:

                    print >>to_file, '  %s => %s %s' % (oldpath, newpath, fid)

                else:

                    print >>to_file, '  %s => %s' % (oldpath, newpath)

        if self.modified or extra_modified:

            print >>to_file, 'modified:'

            show_list(self.modified)

            show_list(extra_modified)

        if show_unchanged and self.unchanged:

            print >>to_file, 'unchanged:'

            show_list(self.unchanged)

def compare_trees(old_tree, new_tree, want_unchanged=False, 

                  specific_files=None, extra_trees=None, 

                  require_versioned=False):

    """Describe changes from one tree to another.

    Returns a TreeDelta with details of added, modified, renamed, and

    deleted entries.

    The root entry is specifically exempt.

    This only considers versioned files.

    want_unchanged

        If true, also list files unchanged from one version to

        the next.

    specific_files

        If supplied, only check for changes to specified names or

        files within them.  When mapping filenames to ids, all matches in all

        trees (including optional extra_trees) are used, and all children of

        matched directories are included.

    extra_trees

        If non-None, a list of more trees to use for looking up file_ids from

        paths

    require_versioned

        If true, an all files are required to be versioned, and

        PathsNotVersionedError will be thrown if they are not.

    """

    # NB: show_status depends on being able to pass in non-versioned files and

    # report them as unknown

    old_tree.lock_read()

    try:

        new_tree.lock_read()

        try:

            trees = (new_tree, old_tree)

            if extra_trees is not None:

                trees = trees + tuple(extra_trees)

            specific_file_ids = tree.find_ids_across_trees(specific_files, 

                trees, require_versioned=require_versioned)

            if specific_files and not specific_file_ids:

                # All files are unversioned, so just return an empty delta

                # _compare_trees would think we want a complete delta

                return TreeDelta()

            return _compare_trees(old_tree, new_tree, want_unchanged,

                                  specific_file_ids)

        finally:

            new_tree.unlock()

    finally:

        old_tree.unlock()

def _compare_trees(old_tree, new_tree, want_unchanged, specific_file_ids):

    from osutils import is_inside_any

    old_inv = old_tree.inventory

    new_inv = new_tree.inventory

    delta = TreeDelta()

    mutter('start compare_trees')

    # TODO: Rather than iterating over the whole tree and then filtering, we

    # could diff just the specified files (if any) and their subtrees.  

    old_files = old_tree.list_files()

    new_files = new_tree.list_files()

    more_old = True

    more_new = True

    added = {}

    removed = {}

    def get_next(iter):

        try:

            return iter.next()

        except StopIteration:

            return None, None, None, None, None

    old_path, old_class, old_kind, old_file_id, old_entry = get_next(old_files)

    new_path, new_class, new_kind, new_file_id, new_entry = get_next(new_files)

    def check_matching(old_path, old_entry, new_path, new_entry):

        """We have matched up 2 file_ids, check for changes."""

        assert old_entry.kind == new_entry.kind

        if old_entry.kind == 'root_directory':

            return

        if specific_file_ids:

            if (old_entry.file_id not in specific_file_ids and 

                new_entry.file_id not in specific_file_ids):

                return

        # temporary hack until all entries are populated before clients 

        # get them

        old_entry._read_tree_state(old_path, old_tree)

        new_entry._read_tree_state(new_path, new_tree)

        text_modified, meta_modified = new_entry.detect_changes(old_entry)

        # If the name changes, or the parent_id changes, we have a rename

        # (if we move a parent, that doesn't count as a rename for the file)

        if (old_entry.name != new_entry.name 

            or old_entry.parent_id != new_entry.parent_id):

            delta.renamed.append((old_path,

                                  new_path,

                                  old_entry.file_id, old_entry.kind,

                                  text_modified, meta_modified))

        elif text_modified or meta_modified:

            delta.modified.append((new_path, new_entry.file_id, new_entry.kind,

                                   text_modified, meta_modified))

        elif want_unchanged:

            delta.unchanged.append((new_path, new_entry.file_id, new_entry.kind))

    def handle_old(path, entry):

        """old entry without a new entry match

        Check to see if a matching new entry was already seen as an

        added file, and switch the pair into being a rename.

        Otherwise just mark the old entry being removed.

        """

        if entry.file_id in added:

            # Actually this is a rename, we found a new file_id earlier

            # at a different location, so it is no-longer added

            x_new_path, x_new_entry = added.pop(entry.file_id)

            check_matching(path, entry, x_new_path, x_new_entry)

        else:

            # We have an old_file_id which doesn't line up with a new_file_id

            # So this file looks to be removed

            assert entry.file_id not in removed

            removed[entry.file_id] = path, entry

    def handle_new(path, entry):

        """new entry without an old entry match

        Check to see if a matching old entry was already seen as a

        removal, and change the pair into a rename.

        Otherwise just mark the new entry as an added file.

        """

        if entry.file_id in removed:

            # We saw this file_id earlier at an old different location

            # it is no longer removed, just renamed

            x_old_path, x_old_entry = removed.pop(entry.file_id)

            check_matching(x_old_path, x_old_entry, path, entry)

        else:

            # We have a new file which does not match an old file

            # mark it as added

            assert entry.file_id not in added

            added[entry.file_id] = path, entry

    while old_path or new_path:

        # list_files() returns files in alphabetical path sorted order

        if old_path == new_path:

            if old_file_id == new_file_id:

                # This is the common case, the files are in the same place

                # check if there were any content changes

                if old_file_id is None:

                    # We have 2 unversioned files, no deltas possible???

                    pass

                else:

                    check_matching(old_path, old_entry, new_path, new_entry)

            else:

                # The ids don't match, so we have to handle them both

                # separately.

                if old_file_id is not None:

                    handle_old(old_path, old_entry)

                if new_file_id is not None:

                    handle_new(new_path, new_entry)

            # The two entries were at the same path, so increment both sides

            old_path, old_class, old_kind, old_file_id, old_entry = get_next(old_files)

            new_path, new_class, new_kind, new_file_id, new_entry = get_next(new_files)

        elif new_path is None or (old_path is not None and old_path < new_path):

            # Assume we don't match, only process old_path

            if old_file_id is not None:

                handle_old(old_path, old_entry)

            # old_path came first, so increment it, trying to match up

            old_path, old_class, old_kind, old_file_id, old_entry = get_next(old_files)

        elif new_path is not None:

            # new_path came first, so increment it, trying to match up

            if new_file_id is not None:

                handle_new(new_path, new_entry)

            new_path, new_class, new_kind, new_file_id, new_entry = get_next(new_files)

    # Now we have a set of added and removed files, mark them all

    for old_path, old_entry in removed.itervalues():

        if specific_file_ids:

            if not old_entry.file_id in specific_file_ids:

                continue

        delta.removed.append((old_path, old_entry.file_id, old_entry.kind))

    for new_path, new_entry in added.itervalues():

        if specific_file_ids:

            if not new_entry.file_id in specific_file_ids:

                continue

        delta.added.append((new_path, new_entry.file_id, new_entry.kind))

    delta.removed.sort()

    delta.added.sort()

    delta.renamed.sort()

    # TODO: jam 20060529 These lists shouldn't need to be sorted

    #       since we added them in alphabetical order.

    delta.modified.sort()

    delta.unchanged.sort()

    return delta