~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

from warnings import warn

import bzrlib

from bzrlib import delta

from bzrlib.decorators import needs_read_lock

from bzrlib.errors import BzrError, BzrCheckError

from bzrlib import errors

from bzrlib.inventory import Inventory

from bzrlib.inter import InterObject

from bzrlib.osutils import fingerprint_file

import bzrlib.revision

from bzrlib.trace import mutter, note

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.

    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 changes_from(self, other, want_unchanged=False, specific_files=None,

        extra_trees=None, require_versioned=False):

        """Return a TreeDelta of the changes from other to this tree.

        :param other: A tree to compare with.

        :param specific_files: An optional list of file paths to restrict the

            comparison to. When mapping filenames to ids, all matches in all

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

            matched directories are included.

        :param want_unchanged: An optional boolean requesting the inclusion of

            unchanged entries in the result.

        :param extra_trees: An optional list of additional trees to use when

            mapping the contents of specific_files (paths) to file_ids.

        :param require_versioned: An optional boolean (defaults to False). When

            supplied and True all the 'specific_files' must be versioned, or

            a PathsNotVersionedError will be thrown.

        The comparison will be performed by an InterTree object looked up on 

        self and other.

        """

        # Martin observes that Tree.changes_from returns a TreeDelta and this

        # may confuse people, because the class name of the returned object is

        # a synonym of the object referenced in the method name.

        return InterTree.get(other, self).compare(

            want_unchanged=want_unchanged,

            specific_files=specific_files,

            extra_trees=extra_trees,

            require_versioned=require_versioned,

            )

    def conflicts(self):

        """Get a list of the conflicts in the tree.

        Each conflict is an instance of bzrlib.conflicts.Conflict.

        """

        return []

    def get_parent_ids(self):

        """Get the parent ids for this tree. 

        :return: a list of parent ids. [] is returned to indicate

        a tree with no parents.

        :raises: BzrError if the parents are not known.

        """

        raise NotImplementedError(self.get_parent_ids)

    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)

    __contains__ = has_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)

    def __iter__(self):

        return iter(self.inventory)

    def id2path(self, file_id):

        return self.inventory.id2path(file_id)

    def iter_entries_by_dir(self):

        """Walk the tree in 'by_dir' order.

        This will yield each entry in the tree as a (path, entry) tuple. The

        order that they are yielded is: the contents of a directory are 

        preceeded by the parent of a directory, and all the contents of a 

        directory are grouped together.

        """

        return self.inventory.iter_entries_by_dir()

    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 unknowns(self):

        """What files are present in this tree and unknown.

        :return: an iterator over the unknown files.

        """

        return iter([])

    def unlock(self):

        pass

    def filter_unversioned_files(self, paths):

        """Filter out paths that are not versioned.

        :return: set of paths.

        """

        # NB: we specifically *don't* call self.has_filename, because for

        # WorkingTrees that can indicate files that exist on disk but that 

        # are not versioned.

        pred = self.inventory.has_filename

        return set((p for p in paths if not pred(p)))

    def walkdirs(self, prefix=""):

        """Walk the contents of this tree from path down.

        This yields all the data about the contents of a directory at a time.

        After each directory has been yielded, if the caller has mutated the

        list to exclude some directories, they are then not descended into.

        The data yielded is of the form:

        [(relpath, basename, kind, lstat, path_from_tree_root, file_id, 

          versioned_kind), ...]

         - relpath is the relative path within the subtree being walked.

         - basename is the basename

         - kind is the kind of the file now. If unknonwn then the file is not

           present within the tree - but it may be recorded as versioned. See

           versioned_kind.

         - lstat is the stat data *if* the file was statted.

         - path_from_tree_root is the path from the root of the tree.

         - file_id is the file_id is the entry is versioned.

         - versioned_kind is the kind of the file as last recorded in the 

           versioning system. If 'unknown' the file is not versioned.

        One of 'kind' and 'versioned_kind' must not be 'unknown'.

        :param prefix: Start walking from prefix within the tree rather than

        at the root. This allows one to walk a subtree but get paths that are

        relative to a tree rooted higher up.

        :return: an iterator over the directory data.

        """

        raise NotImplementedError(self.walkdirs)

# for compatibility

from bzrlib.revisiontree import RevisionTree

class EmptyTree(Tree):

    def __init__(self):

        self._inventory = Inventory()

        warn('EmptyTree is deprecated as of bzr 0.9 please use '

            'repository.revision_tree instead.',

            DeprecationWarning, stacklevel=2)

    def get_parent_ids(self):

        return []

    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, path=None):

        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)

def find_ids_across_trees(filenames, trees, require_versioned=True):

    """Find the ids corresponding to specified filenames.

    All matches in all trees will be used, and all children of matched

    directories will be used.

    :param filenames: The filenames to find file_ids for

    :param trees: The trees to find file_ids within

    :param require_versioned: if true, all specified filenames must occur in

    at least one tree.

    :return: a set of file ids for the specified filenames and their children.

    """

    if not filenames:

        return None

    specified_ids = _find_filename_ids_across_trees(filenames, trees, 

                                                    require_versioned)

    return _find_children_across_trees(specified_ids, trees)

def _find_filename_ids_across_trees(filenames, trees, require_versioned):

    """Find the ids corresponding to specified filenames.

    All matches in all trees will be used.

    :param filenames: The filenames to find file_ids for

    :param trees: The trees to find file_ids within

    :param require_versioned: if true, all specified filenames must occur in

    at least one tree.

    :return: a set of file ids for the specified filenames

    """

    not_versioned = []

    interesting_ids = set()

    for tree_path in filenames:

        not_found = True

        for tree in trees:

            file_id = tree.inventory.path2id(tree_path)

            if file_id is not None:

                interesting_ids.add(file_id)

                not_found = False

        if not_found:

            not_versioned.append(tree_path)

    if len(not_versioned) > 0 and require_versioned:

        raise errors.PathsNotVersionedError(not_versioned)

    return interesting_ids

def _find_children_across_trees(specified_ids, trees):

    """Return a set including specified ids and their children

    All matches in all trees will be used.

    :param trees: The trees to find file_ids within

    :return: a set containing all specified ids and their children 

    """

    interesting_ids = set(specified_ids)

    pending = interesting_ids

    # now handle children of interesting ids

    # we loop so that we handle all children of each id in both trees

    while len(pending) > 0:

        new_pending = set()

        for file_id in pending:

            for tree in trees:

                if file_id not in tree:

                    continue

                entry = tree.inventory[file_id]

                for child in getattr(entry, 'children', {}).itervalues():

                    if child.file_id not in interesting_ids:

                        new_pending.add(child.file_id)

        interesting_ids.update(new_pending)

        pending = new_pending

    return interesting_ids

class InterTree(InterObject):

    """This class represents operations taking place between two Trees.

    Its instances have methods like 'compare' and contain references to the

    source and target trees these operations are to be carried out on.

    clients of bzrlib should not need to use InterTree directly, rather they

    should use the convenience methods on Tree such as 'Tree.compare()' which

    will pass through to InterTree as appropriate.

    """

    _optimisers = set()

    @needs_read_lock

    def compare(self, want_unchanged=False, specific_files=None,

        extra_trees=None, require_versioned=False):

        """Return the changes from source to target.

        :return: A TreeDelta.

        :param specific_files: An optional list of file paths to restrict the

            comparison to. When mapping filenames to ids, all matches in all

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

            matched directories are included.

        :param want_unchanged: An optional boolean requesting the inclusion of

            unchanged entries in the result.

        :param extra_trees: An optional list of additional trees to use when

            mapping the contents of specific_files (paths) to file_ids.

        :param require_versioned: An optional boolean (defaults to False). When

            supplied and True all the 'specific_files' must be versioned, or

            a PathsNotVersionedError will be thrown.

        """

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

        # report them as unknown

        trees = (self.source, self.target)

        if extra_trees is not None:

            trees = trees + tuple(extra_trees)

        specific_file_ids = 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 delta.TreeDelta()

        return delta._compare_trees(self.source, self.target, want_unchanged,

            specific_file_ids)