~bzr-pqm/bzr/bzr.dev

#! /usr/bin/env python

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

# 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 sets import Set

from trace import mutter

from errors import BzrError

def diff_trees(old_tree, new_tree):

    """Compute diff between two trees.

    They may be in different branches and may be working or historical

    trees.

    This only compares the versioned files, paying no attention to

    files which are ignored or unknown.  Those can only be present in

    working trees and can be reported on separately.

    Yields a sequence of (state, id, old_name, new_name, kind).

    Each filename and each id is listed only once.

    """

    ## TODO: Allow specifying a list of files to compare, rather than

    ## doing the whole tree?  (Not urgent.)

    ## TODO: Allow diffing any two inventories, not just the

    ## current one against one.  We mgiht need to specify two

    ## stores to look for the files if diffing two branches.  That

    ## might imply this shouldn't be primarily a Branch method.

    sha_match_cnt = modified_cnt = 0

    old_it = old_tree.list_files()

    new_it = new_tree.list_files()

    def next(it):

        try:

            return it.next()

        except StopIteration:

            return None

    old_item = next(old_it)

    new_item = next(new_it)

    # We step through the two sorted iterators in parallel, trying to

    # keep them lined up.

    while (old_item != None) or (new_item != None):

        # OK, we still have some remaining on both, but they may be

        # out of step.        

        if old_item != None:

            old_name, old_class, old_kind, old_id = old_item

        else:

            old_name = None

        if new_item != None:

            new_name, new_class, new_kind, new_id = new_item

        else:

            new_name = None

        if old_item:

            # can't handle the old tree being a WorkingTree

            assert old_class == 'V'

        if new_item and (new_class != 'V'):

            yield new_class, None, None, new_name, new_kind

            new_item = next(new_it)

        elif (not new_item) or (old_item and (old_name < new_name)):

            if new_tree.has_id(old_id):

                # will be mentioned as renamed under new name

                pass

            else:

                yield 'D', old_id, old_name, None, old_kind

            old_item = next(old_it)

        elif (not old_item) or (new_item and (new_name < old_name)):

            if old_tree.has_id(new_id):

                yield 'R', new_id, old_tree.id2path(new_id), new_name, new_kind

            else:

                yield 'A', new_id, None, new_name, new_kind

            new_item = next(new_it)

        elif old_id != new_id:

            assert old_name == new_name

            # both trees have a file of this name, but it is not the

            # same file.  in other words, the old filename has been

            # overwritten by either a newly-added or a renamed file.

            # (should we return something about the overwritten file?)

            if old_tree.has_id(new_id):

                # renaming, overlying a deleted file

                yield 'R', new_id, old_tree.id2path(new_id), new_name, new_kind

            else:

                yield 'A', new_id, None, new_name, new_kind

            new_item = next(new_it)

            old_item = next(old_it)

        else:

            assert old_id == new_id

            assert old_id != None

            assert old_name == new_name

            assert old_kind == new_kind

            if old_kind == 'directory':

                yield '.', new_id, old_name, new_name, new_kind

            elif old_tree.get_file_sha1(old_id) == new_tree.get_file_sha1(old_id):

                sha_match_cnt += 1

                yield '.', new_id, old_name, new_name, new_kind

            else:

                modified_cnt += 1

                yield 'M', new_id, old_name, new_name, new_kind

            new_item = next(new_it)

            old_item = next(old_it)

    mutter("diff finished: %d SHA matches, %d modified"

           % (sha_match_cnt, modified_cnt))

def show_diff(b, revision, file_list):

    import difflib, sys, types

    if revision == None:

        old_tree = b.basis_tree()

    else:

        old_tree = b.revision_tree(b.lookup_revision(revision))

    new_tree = b.working_tree()

    # TODO: Options to control putting on a prefix or suffix, perhaps as a format string

    old_label = ''

    new_label = ''

    DEVNULL = '/dev/null'

    # Windows users, don't panic about this filename -- it is a

    # special signal to GNU patch that the file should be created or

    # deleted respectively.

    # TODO: Generation of pseudo-diffs for added/deleted files could

    # be usefully made into a much faster special case.

    # TODO: Better to return them in sorted order I think.

    if file_list:

        file_list = [b.relpath(f) for f in file_list]

    # FIXME: If given a file list, compare only those files rather

    # than comparing everything and then throwing stuff away.

    for file_state, fid, old_name, new_name, kind in diff_trees(old_tree, new_tree):

        if file_list and (new_name not in file_list):

            continue

        # Don't show this by default; maybe do it if an option is passed

        # idlabel = '      {%s}' % fid

        idlabel = ''

        def diffit(oldlines, newlines, **kw):

            # FIXME: difflib is wrong if there is no trailing newline.

            # The syntax used by patch seems to be "\ No newline at

            # end of file" following the last diff line from that

            # file.  This is not trivial to insert into the

            # unified_diff output and it might be better to just fix

            # or replace that function.

            # In the meantime we at least make sure the patch isn't

            # mangled.

            # Special workaround for Python2.3, where difflib fails if

            # both sequences are empty.

            if not oldlines and not newlines:

                return

            nonl = False

            if oldlines and (oldlines[-1][-1] != '\n'):

                oldlines[-1] += '\n'

                nonl = True

            if newlines and (newlines[-1][-1] != '\n'):

                newlines[-1] += '\n'

                nonl = True

            ud = difflib.unified_diff(oldlines, newlines, **kw)

            # work-around for difflib being too smart for its own good

            # if /dev/null is "1,0", patch won't recognize it as /dev/null

            if not oldlines:

                ud = list(ud)

                ud[2] = ud[2].replace('-1,0', '-0,0')

            elif not newlines:

                ud = list(ud)

                ud[2] = ud[2].replace('+1,0', '+0,0')

            sys.stdout.writelines(ud)

            if nonl:

                print "\\ No newline at end of file"

            sys.stdout.write('\n')

        if file_state in ['.', '?', 'I']:

            continue

        elif file_state == 'A':

            print '*** added %s %r' % (kind, new_name)

            if kind == 'file':

                diffit([],

                       new_tree.get_file(fid).readlines(),

                       fromfile=DEVNULL,

                       tofile=new_label + new_name + idlabel)

        elif file_state == 'D':

            assert isinstance(old_name, types.StringTypes)

            print '*** deleted %s %r' % (kind, old_name)

            if kind == 'file':

                diffit(old_tree.get_file(fid).readlines(), [],

                       fromfile=old_label + old_name + idlabel,

                       tofile=DEVNULL)

        elif file_state in ['M', 'R']:

            if file_state == 'M':

                assert kind == 'file'

                assert old_name == new_name

                print '*** modified %s %r' % (kind, new_name)

            elif file_state == 'R':

                print '*** renamed %s %r => %r' % (kind, old_name, new_name)

            if kind == 'file':

                diffit(old_tree.get_file(fid).readlines(),

                       new_tree.get_file(fid).readlines(),

                       fromfile=old_label + old_name + idlabel,

                       tofile=new_label + new_name)

        else:

            raise BzrError("can't represent state %s {%s}" % (file_state, fid))

class TreeDelta:

    """Describes changes from one tree to another.

    Contains four lists:

    added

        (path, id)

    removed

        (path, id)

    renamed

        (oldpath, newpath, id, text_modified)

    modified

        (path, id)

    unchanged

        (path, id)

    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 lists are normally sorted when the delta is created.

    """

    def __init__(self):

        self.added = []

        self.removed = []

        self.renamed = []

        self.modified = []

        self.unchanged = []

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

        def show_list(files):

            for path, fid in files:

                if show_ids:

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

                else:

                    print >>to_file, ' ', path

        if self.removed:

            print >>to_file, 'removed files:'

            show_list(self.removed)

        if self.added:

            print >>to_file, 'added files:'

            show_list(self.added)

        if self.renamed:

            print >>to_file, 'renamed files:'

            for oldpath, newpath, fid, text_modified in self.renamed:

                if show_ids:

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

                else:

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

        if self.modified:

            print >>to_file, 'modified files:'

            show_list(self.modified)

        if show_unchanged and self.unchanged:

            print >>to_file, 'unchanged files:'

            show_list(self.unchanged)

def compare_trees(old_tree, new_tree, want_unchanged):

    old_inv = old_tree.inventory

    new_inv = new_tree.inventory

    delta = TreeDelta()

    for file_id in old_tree:

        if file_id in new_tree:

            old_path = old_inv.id2path(file_id)

            new_path = new_inv.id2path(file_id)

            kind = old_inv.get_file_kind(file_id)

            assert kind in ('file', 'directory', 'symlink', 'root_directory'), \

                   'invalid file kind %r' % kind

            if kind == 'file':

                old_sha1 = old_tree.get_file_sha1(file_id)

                new_sha1 = new_tree.get_file_sha1(file_id)

                text_modified = (old_sha1 != new_sha1)

            else:

                ## mutter("no text to check for %r %r" % (file_id, kind))

                text_modified = False

            # TODO: Can possibly avoid calculating path strings if the

            # two files are unchanged and their names and parents are

            # the same and the parents are unchanged all the way up.

            # May not be worthwhile.

            if old_path != new_path:

                delta.renamed.append((old_path, new_path, file_id, text_modified))

            elif text_modified:

                delta.modified.append((new_path, file_id))

            elif want_unchanged:

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

        else:

            delta.removed.append((old_inv.id2path(file_id), file_id))

    for file_id in new_inv:

        if file_id in old_inv:

            continue

        delta.added.append((new_inv.id2path(file_id), file_id))

    delta.removed.sort()

    delta.added.sort()

    delta.renamed.sort()

    delta.modified.sort()

    return delta