~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2006 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

import os

import errno

from stat import S_ISREG

from bzrlib import bzrdir, errors

from bzrlib.errors import (DuplicateKey, MalformedTransform, NoSuchFile,

                           ReusingTransform, NotVersionedError, CantMoveRoot,

                           ExistingLimbo, ImmortalLimbo)

from bzrlib.inventory import InventoryEntry

from bzrlib.osutils import (file_kind, supports_executable, pathjoin, lexists,

                            delete_any)

from bzrlib.progress import DummyProgress, ProgressPhase

from bzrlib.trace import mutter, warning

from bzrlib import tree

import bzrlib.ui 

import bzrlib.urlutils as urlutils

ROOT_PARENT = "root-parent"

def unique_add(map, key, value):

    if key in map:

        raise DuplicateKey(key=key)

    map[key] = value

class _TransformResults(object):

    def __init__(self, modified_paths):

        object.__init__(self)

        self.modified_paths = modified_paths

class TreeTransform(object):

    """Represent a tree transformation.

    This object is designed to support incremental generation of the transform,

    in any order.  

    It is easy to produce malformed transforms, but they are generally

    harmless.  Attempting to apply a malformed transform will cause an

    exception to be raised before any modifications are made to the tree.  

    Many kinds of malformed transforms can be corrected with the 

    resolve_conflicts function.  The remaining ones indicate programming error,

    such as trying to create a file with no path.

    Two sets of file creation methods are supplied.  Convenience methods are:

     * new_file

     * new_directory

     * new_symlink

    These are composed of the low-level methods:

     * create_path

     * create_file or create_directory or create_symlink

     * version_file

     * set_executability

    """

    def __init__(self, tree, pb=DummyProgress()):

        """Note: a tree_write lock is taken on the tree.

        Use TreeTransform.finalize() to release the lock

        """

        object.__init__(self)

        self._tree = tree

        self._tree.lock_tree_write()

        try:

            control_files = self._tree._control_files

            self._limbodir = urlutils.local_path_from_url(

                control_files.controlfilename('limbo'))

            try:

                os.mkdir(self._limbodir)

            except OSError, e:

                if e.errno == errno.EEXIST:

                    raise ExistingLimbo(self._limbodir)

        except: 

            self._tree.unlock()

            raise

        self._id_number = 0

        self._new_name = {}

        self._new_parent = {}

        self._new_contents = {}

        self._removed_contents = set()

        self._new_executability = {}

        self._new_id = {}

        self._non_present_ids = {}

        self._r_new_id = {}

        self._removed_id = set()

        self._tree_path_ids = {}

        self._tree_id_paths = {}

        self._realpaths = {}

        # Cache of realpath results, to speed up canonical_path

        self._relpaths = {}

        # Cache of relpath results, to speed up canonical_path

        self._new_root = self.trans_id_tree_file_id(tree.get_root_id())

        self.__done = False

        self._pb = pb

    def __get_root(self):

        return self._new_root

    root = property(__get_root)

    def finalize(self):

        """Release the working tree lock, if held, clean up limbo dir."""

        if self._tree is None:

            return

        try:

            for trans_id, kind in self._new_contents.iteritems():

                path = self._limbo_name(trans_id)

                if kind == "directory":

                    os.rmdir(path)

                else:

                    os.unlink(path)

            try:

                os.rmdir(self._limbodir)

            except OSError:

                # We don't especially care *why* the dir is immortal.

                raise ImmortalLimbo(self._limbodir)

        finally:

            self._tree.unlock()

            self._tree = None

    def _assign_id(self):

        """Produce a new tranform id"""

        new_id = "new-%s" % self._id_number

        self._id_number +=1

        return new_id

    def create_path(self, name, parent):

        """Assign a transaction id to a new path"""

        trans_id = self._assign_id()

        unique_add(self._new_name, trans_id, name)

        unique_add(self._new_parent, trans_id, parent)

        return trans_id

    def adjust_path(self, name, parent, trans_id):

        """Change the path that is assigned to a transaction id."""

        if trans_id == self._new_root:

            raise CantMoveRoot

        self._new_name[trans_id] = name

        self._new_parent[trans_id] = parent

    def adjust_root_path(self, name, parent):

        """Emulate moving the root by moving all children, instead.

        We do this by undoing the association of root's transaction id with the

        current tree.  This allows us to create a new directory with that

        transaction id.  We unversion the root directory and version the 

        physically new directory, and hope someone versions the tree root

        later.

        """

        old_root = self._new_root

        old_root_file_id = self.final_file_id(old_root)

        # force moving all children of root

        for child_id in self.iter_tree_children(old_root):

            if child_id != parent:

                self.adjust_path(self.final_name(child_id), 

                                 self.final_parent(child_id), child_id)

            file_id = self.final_file_id(child_id)

            if file_id is not None:

                self.unversion_file(child_id)

            self.version_file(file_id, child_id)

        # the physical root needs a new transaction id

        self._tree_path_ids.pop("")

        self._tree_id_paths.pop(old_root)

        self._new_root = self.trans_id_tree_file_id(self._tree.get_root_id())

        if parent == old_root:

            parent = self._new_root

        self.adjust_path(name, parent, old_root)

        self.create_directory(old_root)

        self.version_file(old_root_file_id, old_root)

        self.unversion_file(self._new_root)

    def trans_id_tree_file_id(self, inventory_id):

        """Determine the transaction id of a working tree file.

        This reflects only files that already exist, not ones that will be

        added by transactions.

        """

        path = self._tree.inventory.id2path(inventory_id)

        return self.trans_id_tree_path(path)

    def trans_id_file_id(self, file_id):

        """Determine or set the transaction id associated with a file ID.

        A new id is only created for file_ids that were never present.  If

        a transaction has been unversioned, it is deliberately still returned.

        (this will likely lead to an unversioned parent conflict.)

        """

        if file_id in self._r_new_id and self._r_new_id[file_id] is not None:

            return self._r_new_id[file_id]

        elif file_id in self._tree.inventory:

            return self.trans_id_tree_file_id(file_id)

        elif file_id in self._non_present_ids:

            return self._non_present_ids[file_id]

        else:

            trans_id = self._assign_id()

            self._non_present_ids[file_id] = trans_id

            return trans_id

    def canonical_path(self, path):

        """Get the canonical tree-relative path"""

        # don't follow final symlinks

        abs = self._tree.abspath(path)

        if abs in self._relpaths:

            return self._relpaths[abs]

        dirname, basename = os.path.split(abs)

        if dirname not in self._realpaths:

            self._realpaths[dirname] = os.path.realpath(dirname)

        dirname = self._realpaths[dirname]

        abs = pathjoin(dirname, basename)

        if dirname in self._relpaths:

            relpath = pathjoin(self._relpaths[dirname], basename)

            relpath = relpath.rstrip('/\\')

        else:

            relpath = self._tree.relpath(abs)

        self._relpaths[abs] = relpath

        return relpath

    def trans_id_tree_path(self, path):

        """Determine (and maybe set) the transaction ID for a tree path."""

        path = self.canonical_path(path)

        if path not in self._tree_path_ids:

            self._tree_path_ids[path] = self._assign_id()

            self._tree_id_paths[self._tree_path_ids[path]] = path

        return self._tree_path_ids[path]

    def get_tree_parent(self, trans_id):

        """Determine id of the parent in the tree."""

        path = self._tree_id_paths[trans_id]

        if path == "":

            return ROOT_PARENT

        return self.trans_id_tree_path(os.path.dirname(path))

    def create_file(self, contents, trans_id, mode_id=None):

        """Schedule creation of a new file.

        See also new_file.

        Contents is an iterator of strings, all of which will be written

        to the target destination.

        New file takes the permissions of any existing file with that id,

        unless mode_id is specified.

        """

        name = self._limbo_name(trans_id)

        f = open(name, 'wb')

        try:

            try:

                unique_add(self._new_contents, trans_id, 'file')

            except:

                # Clean up the file, it never got registered so

                # TreeTransform.finalize() won't clean it up.

                f.close()

                os.unlink(name)

                raise

            for segment in contents:

                f.write(segment)

        finally:

            f.close()

        self._set_mode(trans_id, mode_id, S_ISREG)

    def _set_mode(self, trans_id, mode_id, typefunc):

        """Set the mode of new file contents.

        The mode_id is the existing file to get the mode from (often the same

        as trans_id).  The operation is only performed if there's a mode match

        according to typefunc.

        """

        if mode_id is None:

            mode_id = trans_id

        try:

            old_path = self._tree_id_paths[mode_id]

        except KeyError:

            return

        try:

            mode = os.stat(self._tree.abspath(old_path)).st_mode

        except OSError, e:

            if e.errno == errno.ENOENT:

                return

            else:

                raise

        if typefunc(mode):

            os.chmod(self._limbo_name(trans_id), mode)

    def create_directory(self, trans_id):

        """Schedule creation of a new directory.

        See also new_directory.

        """

        os.mkdir(self._limbo_name(trans_id))

        unique_add(self._new_contents, trans_id, 'directory')

    def create_symlink(self, target, trans_id):

        """Schedule creation of a new symbolic link.

        target is a bytestring.

        See also new_symlink.

        """

        os.symlink(target, self._limbo_name(trans_id))

        unique_add(self._new_contents, trans_id, 'symlink')

    def cancel_creation(self, trans_id):

        """Cancel the creation of new file contents."""

        del self._new_contents[trans_id]

        delete_any(self._limbo_name(trans_id))

    def delete_contents(self, trans_id):

        """Schedule the contents of a path entry for deletion"""

        self.tree_kind(trans_id)

        self._removed_contents.add(trans_id)

    def cancel_deletion(self, trans_id):

        """Cancel a scheduled deletion"""

        self._removed_contents.remove(trans_id)

    def unversion_file(self, trans_id):

        """Schedule a path entry to become unversioned"""

        self._removed_id.add(trans_id)

    def delete_versioned(self, trans_id):

        """Delete and unversion a versioned file"""

        self.delete_contents(trans_id)

        self.unversion_file(trans_id)

    def set_executability(self, executability, trans_id):

        """Schedule setting of the 'execute' bit

        To unschedule, set to None

        """

        if executability is None:

            del self._new_executability[trans_id]

        else:

            unique_add(self._new_executability, trans_id, executability)

    def version_file(self, file_id, trans_id):

        """Schedule a file to become versioned."""

        assert file_id is not None

        unique_add(self._new_id, trans_id, file_id)

        unique_add(self._r_new_id, file_id, trans_id)

    def cancel_versioning(self, trans_id):

        """Undo a previous versioning of a file"""

        file_id = self._new_id[trans_id]

        del self._new_id[trans_id]

        del self._r_new_id[file_id]

    def new_paths(self):

        """Determine the paths of all new and changed files"""

        new_ids = set()

        fp = FinalPaths(self)

        for id_set in (self._new_name, self._new_parent, self._new_contents,

                       self._new_id, self._new_executability):

            new_ids.update(id_set)

        new_paths = [(fp.get_path(t), t) for t in new_ids]

        new_paths.sort()

        return new_paths

    def tree_kind(self, trans_id):

        """Determine the file kind in the working tree.

        Raises NoSuchFile if the file does not exist

        """

        path = self._tree_id_paths.get(trans_id)

        if path is None:

            raise NoSuchFile(None)

        try:

            return file_kind(self._tree.abspath(path))

        except OSError, e:

            if e.errno != errno.ENOENT:

                raise

            else:

                raise NoSuchFile(path)

    def final_kind(self, trans_id):

        """Determine the final file kind, after any changes applied.

        Raises NoSuchFile if the file does not exist/has no contents.

        (It is conceivable that a path would be created without the

        corresponding contents insertion command)

        """

        if trans_id in self._new_contents:

            return self._new_contents[trans_id]

        elif trans_id in self._removed_contents:

            raise NoSuchFile(None)

        else:

            return self.tree_kind(trans_id)

    def tree_file_id(self, trans_id):

        """Determine the file id associated with the trans_id in the tree"""

        try:

            path = self._tree_id_paths[trans_id]

        except KeyError:

            # the file is a new, unversioned file, or invalid trans_id

            return None

        # the file is old; the old id is still valid

        if self._new_root == trans_id:

            return self._tree.inventory.root.file_id

        return self._tree.inventory.path2id(path)

    def final_file_id(self, trans_id):

        """Determine the file id after any changes are applied, or None.

        None indicates that the file will not be versioned after changes are

        applied.

        """

        try:

            # there is a new id for this file

            assert self._new_id[trans_id] is not None

            return self._new_id[trans_id]

        except KeyError:

            if trans_id in self._removed_id:

                return None

        return self.tree_file_id(trans_id)

    def inactive_file_id(self, trans_id):

        """Return the inactive file_id associated with a transaction id.

        That is, the one in the tree or in non_present_ids.

        The file_id may actually be active, too.

        """

        file_id = self.tree_file_id(trans_id)

        if file_id is not None:

            return file_id

        for key, value in self._non_present_ids.iteritems():

            if value == trans_id:

                return key

    def final_parent(self, trans_id):

        """Determine the parent file_id, after any changes are applied.

        ROOT_PARENT is returned for the tree root.

        """

        try:

            return self._new_parent[trans_id]

        except KeyError:

            return self.get_tree_parent(trans_id)

    def final_name(self, trans_id):

        """Determine the final filename, after all changes are applied."""

        try:

            return self._new_name[trans_id]

        except KeyError:

            return os.path.basename(self._tree_id_paths[trans_id])

    def by_parent(self):

        """Return a map of parent: children for known parents.

        Only new paths and parents of tree files with assigned ids are used.

        """

        by_parent = {}

        items = list(self._new_parent.iteritems())

        items.extend((t, self.final_parent(t)) for t in 

                      self._tree_id_paths.keys())

        for trans_id, parent_id in items:

            if parent_id not in by_parent:

                by_parent[parent_id] = set()

            by_parent[parent_id].add(trans_id)

        return by_parent

    def path_changed(self, trans_id):

        """Return True if a trans_id's path has changed."""

        return (trans_id in self._new_name) or (trans_id in self._new_parent)

    def new_contents(self, trans_id):

        return (trans_id in self._new_contents)

    def find_conflicts(self):

        """Find any violations of inventory or filesystem invariants"""

        if self.__done is True:

            raise ReusingTransform()

        conflicts = []

        # ensure all children of all existent parents are known

        # all children of non-existent parents are known, by definition.

        self._add_tree_children()

        by_parent = self.by_parent()

        conflicts.extend(self._unversioned_parents(by_parent))

        conflicts.extend(self._parent_loops())

        conflicts.extend(self._duplicate_entries(by_parent))

        conflicts.extend(self._duplicate_ids())

        conflicts.extend(self._parent_type_conflicts(by_parent))

        conflicts.extend(self._improper_versioning())

        conflicts.extend(self._executability_conflicts())

        conflicts.extend(self._overwrite_conflicts())

        return conflicts

    def _add_tree_children(self):

        """Add all the children of all active parents to the known paths.

        Active parents are those which gain children, and those which are

        removed.  This is a necessary first step in detecting conflicts.

        """

        parents = self.by_parent().keys()

        parents.extend([t for t in self._removed_contents if 

                        self.tree_kind(t) == 'directory'])

        for trans_id in self._removed_id:

            file_id = self.tree_file_id(trans_id)

            if self._tree.inventory[file_id].kind == 'directory':

                parents.append(trans_id)

        for parent_id in parents:

            # ensure that all children are registered with the transaction

            list(self.iter_tree_children(parent_id))

    def iter_tree_children(self, parent_id):

        """Iterate through the entry's tree children, if any"""

        try:

            path = self._tree_id_paths[parent_id]

        except KeyError:

            return

        try:

            children = os.listdir(self._tree.abspath(path))

        except OSError, e:

            if e.errno != errno.ENOENT and e.errno != errno.ESRCH:

                raise

            return

        for child in children:

            childpath = joinpath(path, child)

            if self._tree.is_control_filename(childpath):

                continue

            yield self.trans_id_tree_path(childpath)

    def has_named_child(self, by_parent, parent_id, name):

        try:

            children = by_parent[parent_id]

        except KeyError:

            children = []

        for child in children:

            if self.final_name(child) == name:

                return True

        try:

            path = self._tree_id_paths[parent_id]

        except KeyError:

            return False

        childpath = joinpath(path, name)

        child_id = self._tree_path_ids.get(childpath)

        if child_id is None:

            return lexists(self._tree.abspath(childpath))

        else:

            if self.final_parent(child_id) != parent_id:

                return False

            if child_id in self._removed_contents:

                # XXX What about dangling file-ids?

                return False

            else:

                return True

    def _parent_loops(self):

        """No entry should be its own ancestor"""

        conflicts = []

        for trans_id in self._new_parent:

            seen = set()

            parent_id = trans_id

            while parent_id is not ROOT_PARENT:

                seen.add(parent_id)

                parent_id = self.final_parent(parent_id)

                if parent_id == trans_id:

                    conflicts.append(('parent loop', trans_id))

                if parent_id in seen:

                    break

        return conflicts

    def _unversioned_parents(self, by_parent):

        """If parent directories are versioned, children must be versioned."""

        conflicts = []

        for parent_id, children in by_parent.iteritems():

            if parent_id is ROOT_PARENT:

                continue

            if self.final_file_id(parent_id) is not None:

                continue

            for child_id in children:

                if self.final_file_id(child_id) is not None:

                    conflicts.append(('unversioned parent', parent_id))

                    break;

        return conflicts

    def _improper_versioning(self):

        """Cannot version a file with no contents, or a bad type.

        However, existing entries with no contents are okay.

        """

        conflicts = []

        for trans_id in self._new_id.iterkeys():

            try:

                kind = self.final_kind(trans_id)

            except NoSuchFile:

                conflicts.append(('versioning no contents', trans_id))

                continue

            if not InventoryEntry.versionable_kind(kind):

                conflicts.append(('versioning bad kind', trans_id, kind))

        return conflicts

    def _executability_conflicts(self):

        """Check for bad executability changes.

        Only versioned files may have their executability set, because

        1. only versioned entries can have executability under windows

        2. only files can be executable.  (The execute bit on a directory

           does not indicate searchability)

        """

        conflicts = []

        for trans_id in self._new_executability:

            if self.final_file_id(trans_id) is None:

                conflicts.append(('unversioned executability', trans_id))

            else:

                try:

                    non_file = self.final_kind(trans_id) != "file"

                except NoSuchFile:

                    non_file = True

                if non_file is True:

                    conflicts.append(('non-file executability', trans_id))

        return conflicts

    def _overwrite_conflicts(self):

        """Check for overwrites (not permitted on Win32)"""

        conflicts = []

        for trans_id in self._new_contents:

            try:

                self.tree_kind(trans_id)

            except NoSuchFile:

                continue

            if trans_id not in self._removed_contents:

                conflicts.append(('overwrite', trans_id,

                                 self.final_name(trans_id)))

        return conflicts

    def _duplicate_entries(self, by_parent):

        """No directory may have two entries with the same name."""

        conflicts = []