~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 Canonical Ltd

# 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

"""Tree classes, representing directory at point in time.

"""

import os

from cStringIO import StringIO

import bzrlib

from bzrlib.trace import mutter, note

from bzrlib.errors import BzrError, BzrCheckError

from bzrlib.inventory import Inventory

from bzrlib.osutils import appendpath, fingerprint_file

class Tree(object):

    """Abstract file tree.

    There are several subclasses:

    * `WorkingTree` exists as files on disk editable by the user.

    * `RevisionTree` is a tree as recorded at some point in the past.

    * `EmptyTree`

    Trees contain an `Inventory` object, and also know how to retrieve

    file texts mentioned in the inventory, either from a working

    directory or from a store.

    It is possible for trees to contain files that are not described

    in their inventory or vice versa; for this use `filenames()`.

    Trees can be compared, etc, regardless of whether they are working

    trees or versioned trees.

    """

    def has_filename(self, filename):

        """True if the tree has given filename."""

        raise NotImplementedError()

    def has_id(self, file_id):

        return self.inventory.has_id(file_id)

    def has_or_had_id(self, file_id):

        if file_id == self.inventory.root.file_id:

            return True

        return self.inventory.has_id(file_id)

    __contains__ = has_id

    def __iter__(self):

        return iter(self.inventory)

    def id2path(self, file_id):

        return self.inventory.id2path(file_id)

    def kind(self, file_id):

        raise NotImplementedError("subclasses must implement kind")

    def _get_inventory(self):

        return self._inventory

    def get_file_by_path(self, path):

        return self.get_file(self._inventory.path2id(path))

    inventory = property(_get_inventory,

                         doc="Inventory of this Tree")

    def _check_retrieved(self, ie, f):

        if not __debug__:

            return  

        fp = fingerprint_file(f)

        f.seek(0)

        if ie.text_size != None:

            if ie.text_size != fp['size']:

                raise BzrError("mismatched size for file %r in %r" % (ie.file_id, self._store),

                        ["inventory expects %d bytes" % ie.text_size,

                         "file is actually %d bytes" % fp['size'],

                         "store is probably damaged/corrupt"])

        if ie.text_sha1 != fp['sha1']:

            raise BzrError("wrong SHA-1 for file %r in %r" % (ie.file_id, self._store),

                    ["inventory expects %s" % ie.text_sha1,

                     "file is actually %s" % fp['sha1'],

                     "store is probably damaged/corrupt"])

    def print_file(self, file_id):

        """Print file with id `file_id` to stdout."""

        import sys

        sys.stdout.write(self.get_file_text(file_id))

    def lock_read(self):

        pass

    def unlock(self):

        pass

class RevisionTree(Tree):

    """Tree viewing a previous revision.

    File text can be retrieved from the text store.

    TODO: Some kind of `__repr__` method, but a good one

           probably means knowing the branch and revision number,

           or at least passing a description to the constructor.

    """

    def __init__(self, branch, inv, revision_id):

        self._branch = branch

        self._weave_store = branch.weave_store

        self._inventory = inv

        self._revision_id = revision_id

    def get_weave(self, file_id):

        return self._weave_store.get_weave(file_id,

                self._branch.get_transaction())

    def get_file_lines(self, file_id):

        ie = self._inventory[file_id]

        weave = self.get_weave(file_id)

        return weave.get_lines(ie.revision)

    def get_file_text(self, file_id):

        return ''.join(self.get_file_lines(file_id))

    def get_file(self, file_id):

        return StringIO(self.get_file_text(file_id))

    def get_file_size(self, file_id):

        return self._inventory[file_id].text_size

    def get_file_sha1(self, file_id):

        ie = self._inventory[file_id]

        if ie.kind == "file":

            return ie.text_sha1

    def is_executable(self, file_id):

        ie = self._inventory[file_id]

        if ie.kind != "file":

            return None 

        return self._inventory[file_id].executable

    def has_filename(self, filename):

        return bool(self.inventory.path2id(filename))

    def list_files(self):

        # The only files returned by this are those from the version

        for path, entry in self.inventory.iter_entries():

            yield path, 'V', entry.kind, entry.file_id, entry

    def get_symlink_target(self, file_id):

        ie = self._inventory[file_id]

        return ie.symlink_target;

    def kind(self, file_id):

        return self._inventory[file_id].kind

    def lock_read(self):

        self._branch.lock_read()

    def unlock(self):

        self._branch.unlock()

class EmptyTree(Tree):

    def __init__(self):

        self._inventory = Inventory()

    def get_symlink_target(self, file_id):

        return None

    def has_filename(self, filename):

        return False

    def kind(self, file_id):

        assert self._inventory[file_id].kind == "root_directory"

        return "root_directory"

    def list_files(self):

        return iter([])

    def __contains__(self, file_id):

        return file_id in self._inventory

    def get_file_sha1(self, file_id):

        assert self._inventory[file_id].kind == "root_directory"

        return None

######################################################################

# diff

# TODO: Merge these two functions into a single one that can operate

# on either a whole tree or a set of files.

# TODO: Return the diff in order by filename, not by category or in

# random order.  Can probably be done by lock-stepping through the

# filenames from both trees.

def file_status(filename, old_tree, new_tree):

    """Return single-letter status, old and new names for a file.

    The complexity here is in deciding how to represent renames;

    many complex cases are possible.

    """

    old_inv = old_tree.inventory

    new_inv = new_tree.inventory

    new_id = new_inv.path2id(filename)

    old_id = old_inv.path2id(filename)

    if not new_id and not old_id:

        # easy: doesn't exist in either; not versioned at all

        if new_tree.is_ignored(filename):

            return 'I', None, None

        else:

            return '?', None, None

    elif new_id:

        # There is now a file of this name, great.

        pass

    else:

        # There is no longer a file of this name, but we can describe

        # what happened to the file that used to have

        # this name.  There are two possibilities: either it was

        # deleted entirely, or renamed.

        assert old_id

        if new_inv.has_id(old_id):

            return 'X', old_inv.id2path(old_id), new_inv.id2path(old_id)

        else:

            return 'D', old_inv.id2path(old_id), None

    # if the file_id is new in this revision, it is added

    if new_id and not old_inv.has_id(new_id):

        return 'A'

    # if there used to be a file of this name, but that ID has now

    # disappeared, it is deleted

    if old_id and not new_inv.has_id(old_id):

        return 'D'

    return 'wtf?'

def find_renames(old_inv, new_inv):

    for file_id in old_inv:

        if file_id not in new_inv:

            continue

        old_name = old_inv.id2path(file_id)

        new_name = new_inv.id2path(file_id)

        if old_name != new_name:

            yield (old_name, new_name)