/brz/remove-bazaar

# 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 tempfile import mkdtemp

from shutil import rmtree

from stat import S_ISREG

from bzrlib import BZRDIR

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

                           ReusingTransform, NotVersionedError, CantMoveRoot,

                           WorkingTreeNotRevision)

from bzrlib.inventory import InventoryEntry

from bzrlib.osutils import file_kind, supports_executable, pathjoin

from bzrlib.merge3 import Merge3

from bzrlib.trace import mutter

ROOT_PARENT = "root-parent"

def unique_add(map, key, value):

    if key in map:

        raise DuplicateKey(key=key)

    map[key] = value

class TreeTransform(object):

    """Represent a tree transformation."""

    def __init__(self, tree):

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

        Use TreeTransform.finalize() to release the lock

        """

        object.__init__(self)

        self._tree = tree

        self._tree.lock_write()

        self._id_number = 0

        self._new_name = {}

        self._new_parent = {}

        self._new_contents = {}

        self._removed_contents = set()

        self._new_executability = {}

        self._new_id = {}

        self._r_new_id = {}

        self._removed_id = set()

        self._tree_path_ids = {}

        self._tree_id_paths = {}

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

        self.__done = False

        # XXX use the WorkingTree LockableFiles, when available

        control_files = self._tree.branch.control_files

        self._limbodir = control_files.controlfilename('limbo')

        os.mkdir(self._limbodir)

    def finalize(self):

        """Release the working tree lock, if held."""

        if self._tree is None:

            return

        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)

        os.rmdir(self._limbodir)

        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.get_id_tree(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 get_id_tree(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.

        """

        return self.get_tree_path_id(self._tree.id2path(inventory_id))

    def get_trans_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.get_id_tree(file_id)

        else:

            trans_id = self._assign_id()

            self.version_file(file_id, trans_id)

            return trans_id

    def canonical_path(self, path):

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

        # don't follow final symlinks

        dirname, basename = os.path.split(self._tree.abspath(path))

        dirname = os.path.realpath(dirname)

        return self._tree.relpath(os.path.join(dirname, basename))

    def get_tree_path_id(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.get_tree_path_id(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.

        """

        f = file(self._limbo_name(trans_id), 'wb')

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

        for segment in contents:

            f.write(segment)

        f.close()

        self._set_mode(trans_id, mode_id, S_ISREG)

    def _set_mode(self, trans_id, mode_id, 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(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')

    @staticmethod

    def delete_any(full_path):

        try:

            os.unlink(full_path)

        except OSError, e:

        # We may be renaming a dangling inventory id

            if e.errno != errno.EISDIR and e.errno != errno.EACCES:

                raise

            os.rmdir(full_path)

    def cancel_creation(self, trans_id):

        del self._new_contents[trans_id]

        self.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"""

        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."""

        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._new_root, 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 get_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.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

            return self._new_id[trans_id]

        except KeyError:

            if trans_id in self._removed_id:

                return None

        return self.get_tree_file_id(trans_id)

    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 trans_id in self._new_name or trans_id in self._new_parent

    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())

        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.get_tree_file_id(trans_id)

            if self._tree.inventory[file_id].kind in ('directory', 

                                                      'root_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 childpath == BZRDIR:

                continue

            yield self.get_tree_path_id(childpath)

    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 _duplicate_entries(self, by_parent):

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

        conflicts = []

        for children in by_parent.itervalues():

            name_ids = [(self.final_name(t), t) for t in children]

            name_ids.sort()

            last_name = None

            last_trans_id = None

            for name, trans_id in name_ids:

                if name == last_name:

                    conflicts.append(('duplicate', last_trans_id, trans_id,

                    name))

                last_name = name

                last_trans_id = trans_id

        return conflicts

    def _duplicate_ids(self):

        """Each inventory id may only be used once"""

        conflicts = []

        removed_tree_ids = set((self.get_tree_file_id(trans_id) for trans_id in

                                self._removed_id))

        active_tree_ids = set((f for f in self._tree.inventory if

                               f not in removed_tree_ids))

        for trans_id, file_id in self._new_id.iteritems():

            if file_id in active_tree_ids:

                old_trans_id = self.get_id_tree(file_id)

                conflicts.append(('duplicate id', old_trans_id, trans_id))

        return conflicts

    def _parent_type_conflicts(self, by_parent):

        """parents must have directory 'contents'."""

        conflicts = []

        for parent_id, children in by_parent.iteritems():

            if parent_id is ROOT_PARENT:

                continue

            if not self._any_contents(children):

                continue

            for child in children:

                try:

                    self.final_kind(child)

                except NoSuchFile:

                    continue

            try:

                kind = self.final_kind(parent_id)

            except NoSuchFile:

                kind = None

            if kind is None:

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

            elif kind != "directory":

                conflicts.append(('non-directory parent', parent_id))

        return conflicts

    def _any_contents(self, trans_ids):

        """Return true if any of the trans_ids, will have contents."""

        for trans_id in trans_ids:

            try:

                kind = self.final_kind(trans_id)

            except NoSuchFile:

                continue

            return True

        return False

    def apply(self):

        """\

        Apply all changes to the inventory and filesystem.

        If filesystem or inventory conflicts are present, MalformedTransform

        will be thrown.

        """

        conflicts = self.find_conflicts()

        if len(conflicts) != 0:

            raise MalformedTransform(conflicts=conflicts)

        limbo_inv = {}

        inv = self._tree.inventory

        self._apply_removals(inv, limbo_inv)

        self._apply_insertions(inv, limbo_inv)

        self._tree._write_inventory(inv)

        self.__done = True

        self.finalize()

    def _limbo_name(self, trans_id):

        """Generate the limbo name of a file"""

        return os.path.join(self._limbodir, trans_id)

    def _apply_removals(self, inv, limbo_inv):

        """Perform tree operations that remove directory/inventory names.

        That is, delete files that are to be deleted, and put any files that

        need renaming into limbo.  This must be done in strict child-to-parent

        order.

        """

        tree_paths = list(self._tree_path_ids.iteritems())

        tree_paths.sort(reverse=True)

        for path, trans_id in tree_paths:

            full_path = self._tree.abspath(path)

            if trans_id in self._removed_contents:

                self.delete_any(full_path)

            elif trans_id in self._new_name or trans_id in self._new_parent:

                try:

                    os.rename(full_path, self._limbo_name(trans_id))

                except OSError, e:

                    if e.errno != errno.ENOENT:

                        raise

            if trans_id in self._removed_id:

                if trans_id == self._new_root:

                    file_id = self._tree.inventory.root.file_id

                else:

                    file_id = self.get_tree_file_id(trans_id)

                del inv[file_id]

            elif trans_id in self._new_name or trans_id in self._new_parent:

                file_id = self.get_tree_file_id(trans_id)

                if file_id is not None:

                    limbo_inv[trans_id] = inv[file_id]

                    del inv[file_id]

    def _apply_insertions(self, inv, limbo_inv):

        """Perform tree operations that insert directory/inventory names.

        That is, create any files that need to be created, and restore from

        limbo any files that needed renaming.  This must be done in strict

        parent-to-child order.

        """

        for path, trans_id in self.new_paths():

            try:

                kind = self._new_contents[trans_id]

            except KeyError:

                kind = contents = None

            if trans_id in self._new_contents or self.path_changed(trans_id):

                full_path = self._tree.abspath(path)

                try:

                    os.rename(self._limbo_name(trans_id), full_path)

                except OSError, e:

                    # We may be renaming a dangling inventory id

                    if e.errno != errno.ENOENT:

                        raise

                if trans_id in self._new_contents: