~bzr-pqm/bzr/bzr.dev

import os
from bzrlib.errors import (DuplicateKey, MalformedTransform, NoSuchFile,
                           ReusingTransform)
from bzrlib.osutils import file_kind, supports_executable
from bzrlib.inventory import InventoryEntry
from bzrlib import BZRDIR
from bzrlib.delta import compare_trees
import errno

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._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

    def finalize(self):
        """Release the working tree lock, if held."""
        if self._tree is None:
            return
        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."""
        self._new_name[trans_id] = name
        self._new_parent[trans_id] = parent

    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 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):
        """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.
        """
        unique_add(self._new_contents, trans_id, ('file', contents))

    def create_directory(self, trans_id):
        """Schedule creation of a new directory.
        
        See also new_directory.
        """
        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.
        """
        unique_add(self._new_contents, trans_id, ('symlink', target))

    def delete_contents(self, trans_id):
        """Schedule the contents of a path entry for deletion"""
        self._removed_contents.add(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)

    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][0]
        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
        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)
        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 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._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'])
        parents.extend([t for t in self._removed_id if 
                        self.tree_kind(t) == 'directory'])
        for parent_id in parents:
            try:
                path = self._tree_id_paths[parent_id]
            except KeyError:
                continue
            try:
                children = os.listdir(self._tree.abspath(path))
            except OSError, e:
                if e.errno != errno.ENOENT:
                    raise
                continue
                
            for child in children:
                childpath = joinpath(path, child)
                if childpath == BZRDIR:
                    continue
                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 _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.
        """
        if len(self.find_conflicts()) != 0:
            raise MalformedTransform()
        os.mkdir(self._tree.branch.controlfilename('limbo'))
        limbo_inv = {}
        inv = self._tree.inventory
        self._apply_removals(inv, limbo_inv)
        self._apply_insertions(inv, limbo_inv)
        os.rmdir(self._tree.branch.controlfilename('limbo'))
        self._tree._write_inventory(inv)
        self.__done = True

    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.
        """
        limbo = self._tree.branch.controlfilename('limbo')
        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:
                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)
            elif trans_id in self._new_name or trans_id in self._new_parent:
                try:
                    os.rename(full_path, os.path.join(limbo, trans_id))
                except OSError, e:
                    if e.errno != errno.ENOENT:
                        raise
            if trans_id in self._removed_id:
                del inv[self.get_tree_file_id(trans_id)]
            elif trans_id in self._new_name or trans_id in self._new_parent:
                file_id = self.get_tree_file_id(trans_id)
                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.
        """
        limbo = self._tree.branch.controlfilename('limbo')
        for path, trans_id in self.new_paths():
            try:
                kind = self._new_contents[trans_id][0]
            except KeyError:
                kind = contents = None
            if kind == 'file':
                contents = self._new_contents[trans_id][1]
                f = file(self._tree.abspath(path), 'wb')
                for segment in contents:
                    f.write(segment)
                f.close()
            elif kind == 'directory':
                os.mkdir(self._tree.abspath(path))
            elif kind == 'symlink':
                target = self._new_contents[trans_id][1]
                os.symlink(target, self._tree.abspath(path))
            elif kind is None and (trans_id in self._new_name or
                                   trans_id in self._new_parent):
                full_path = self._tree.abspath(path)
                try:
                    os.rename(os.path.join(limbo, 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_id:
                if kind is None:
                    kind = file_kind(self._tree.abspath(path))
                inv.add_path(path, kind, self._new_id[trans_id])
            elif trans_id in self._new_name or trans_id in self._new_parent:
                entry = limbo_inv[trans_id]
                entry.name = self.final_name(trans_id)
                parent_trans_id = self.final_parent(trans_id)
                entry.parent_id = self.final_file_id(parent_trans_id)
                inv.add(entry)

            # requires files and inventory entries to be in place
            if trans_id in self._new_executability:
                self._set_executability(path, inv, trans_id)

    def _set_executability(self, path, inv, trans_id):
        """Set the executability of versioned files """
        file_id = inv.path2id(path)
        new_executability = self._new_executability[trans_id]
        inv[file_id].executable = new_executability
        if supports_executable():
            abspath = self._tree.abspath(path)
            current_mode = os.stat(abspath).st_mode
            if new_executability:
                umask = os.umask(0)
                os.umask(umask)
                to_mode = current_mode | (0100 & ~umask)
                # Enable x-bit for others only if they can read it.
                if current_mode & 0004:
                    to_mode |= 0001 & ~umask
                if current_mode & 0040:
                    to_mode |= 0010 & ~umask
            else:
                to_mode = current_mode & ~0111
            os.chmod(abspath, to_mode)

    def _new_entry(self, name, parent_id, file_id):
        """Helper function to create a new filesystem entry."""
        trans_id = self.create_path(name, parent_id)
        if file_id is not None:
            self.version_file(file_id, trans_id)
        return trans_id

    def new_file(self, name, parent_id, contents, file_id=None, 
                 executable=None):
        """\
        Convenience method to create files.
        
        name is the name of the file to create.
        parent_id is the transaction id of the parent directory of the file.
        contents is an iterator of bytestrings, which will be used to produce
        the file.
        file_id is the inventory ID of the file, if it is to be versioned.
        """
        trans_id = self._new_entry(name, parent_id, file_id)
        self.create_file(contents, trans_id)
        if executable is not None:
            self.set_executability(executable, trans_id)
        return trans_id

    def new_directory(self, name, parent_id, file_id=None):
        """\
        Convenience method to create directories.

        name is the name of the directory to create.
        parent_id is the transaction id of the parent directory of the
        directory.
        file_id is the inventory ID of the directory, if it is to be versioned.
        """
        trans_id = self._new_entry(name, parent_id, file_id)
        self.create_directory(trans_id)
        return trans_id 

    def new_symlink(self, name, parent_id, target, file_id=None):
        """\
        Convenience method to create symbolic link.
        
        name is the name of the symlink to create.
        parent_id is the transaction id of the parent directory of the symlink.
        target is a bytestring of the target of the symlink.
        file_id is the inventory ID of the file, if it is to be versioned.
        """
        trans_id = self._new_entry(name, parent_id, file_id)
        self.create_symlink(target, trans_id)
        return trans_id

def joinpath(parent, child):
    """Join tree-relative paths, handling the tree root specially"""
    if parent is None or parent == "":
        return child
    else:
        return os.path.join(parent, child)

class FinalPaths(object):
    """\
    Make path calculation cheap by memoizing paths.

    The underlying tree must not be manipulated between calls, or else
    the results will likely be incorrect.
    """
    def __init__(self, root, transform):
        object.__init__(self)
        self.root = root
        self._known_paths = {}
        self.transform = transform

    def _determine_path(self, trans_id):
        if trans_id == self.root:
            return ""
        name = self.transform.final_name(trans_id)
        parent_id = self.transform.final_parent(trans_id)
        if parent_id == self.root:
            return name
        else:
            return os.path.join(self.get_path(parent_id), name)

    def get_path(self, trans_id):
        if trans_id not in self._known_paths:
            self._known_paths[trans_id] = self._determine_path(trans_id)
        return self._known_paths[trans_id]

def topology_sorted_ids(tree):
    """Determine the topological order of the ids in a tree"""
    file_ids = list(tree)
    file_ids.sort(key=tree.id2path)
    return file_ids

def build_tree(branch, tree):
    """Create working tree for a branch, using a Transaction."""
    file_trans_id = {}
    wt = branch.working_tree()
    tt = TreeTransform(wt)
    try:
        file_trans_id[wt.get_root_id()] = tt.get_id_tree(wt.get_root_id())
        file_ids = topology_sorted_ids(tree)
        for file_id in file_ids:
            entry = tree.inventory[file_id]
            if entry.parent_id is None:
                continue
            if entry.parent_id not in file_trans_id:
                raise repr(entry.parent_id)
            parent_id = file_trans_id[entry.parent_id]
            file_trans_id[file_id] = new_by_entry(tt, entry, parent_id, tree)
        tt.apply()
    finally:
        tt.finalize()

def new_by_entry(tt, entry, parent_id, tree):
    name = entry.name
    kind = entry.kind
    if kind == 'file':
        contents = tree.get_file_lines(entry.file_id)
        executable = tree.is_executable(entry.file_id)
        return tt.new_file(name, parent_id, contents, entry.file_id, 
                           executable)
    elif kind == 'directory':
        return tt.new_directory(name, parent_id, file_id)
    elif kind == 'symlink':
        target = entry.get_symlink_target(file_id)
        return tt.new_symlink(name, parent_id, target, file_id)

def create_by_entry(tt, entry, tree, trans_id):
    if entry.kind == "file":
        tt.create_file(tree.get_file_lines(entry.file_id), trans_id)
        tt.set_executability(entry.executable, trans_id)
    elif entry.kind == "symlink":
        tt.create_symlink(entry.target, trans_id)
    elif entry.kind == "directory":
        tt.create_directory()


def revert(working_tree, target_tree):
    tt = TreeTransform(working_tree)
    try:
        delta = compare_trees(target_tree, working_tree)
        new_ids = {}
        for path, file_id, kind in delta.added:
            trans_id = tt.get_tree_path_id(path)
            tt.unversion_file(trans_id)

        for path, file_id, kind in delta.removed:
            entry = target_tree.inventory[file_id]
            try:
                parent_id = new_ids[entry.parent_id]
            except KeyError:
                parent_id = tt.get_id_tree(entry.parent_id)
            trans_id = tt.get_id_tree(file_id)
            if trans_id is None:
                new_ids[entry.file_id] = new_by_entry(tt, entry, parent_id, 
                                                      target_tree)
            else:
                create_by_entry(tt, entry, target_tree, trans_id)
                if tt.final_parent(trans_id) != parent_id or\
                    tt.final_name(trans_id) != entry.name:
                    tt.adjust_path(entry.name, parent_id, trans_id)

        for path, file_id, kind, text_modified, meta_modified in delta.modified:
            trans_id = tt.get_id_tree(file_id)
            if text_modified is True:
                tt.delete_contents(trans_id)
                entry = target_tree.inventory[file_id]
                create_by_entry(tt, entry, target_tree, trans_id)
            elif meta_modified is True:
                if kind == "file":
                    entry = target_tree.inventory[file_id]
                    tt.set_executability(entry.executable, trans_id)
        tt.apply()
    finally:
        tt.finalize()