~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2008, 2009 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Inventory delta serialisation.

See doc/developers/inventory.txt for the description of the format.

In this module the interesting classes are:

 - InventoryDeltaSerializer - object to read/write inventory deltas.

"""

__all__ = ['InventoryDeltaSerializer']

from bzrlib import errors

from bzrlib.osutils import basename

from bzrlib import inventory

from bzrlib.revision import NULL_REVISION

def _directory_content(entry):

    """Serialize the content component of entry which is a directory.

    :param entry: An InventoryDirectory.

    """

    return "dir"

def _file_content(entry):

    """Serialize the content component of entry which is a file.

    :param entry: An InventoryFile.

    """

    if entry.executable:

        exec_bytes = 'Y'

    else:

        exec_bytes = ''

    size_exec_sha = (entry.text_size, exec_bytes, entry.text_sha1)

    if None in size_exec_sha:

        raise errors.BzrError('Missing size or sha for %s' % entry.file_id)

    return "file\x00%d\x00%s\x00%s" % size_exec_sha

def _link_content(entry):

    """Serialize the content component of entry which is a symlink.

    :param entry: An InventoryLink.

    """

    target = entry.symlink_target

    if target is None:

        raise errors.BzrError('Missing target for %s' % entry.file_id)

    return "link\x00%s" % target.encode('utf8')

def _reference_content(entry):

    """Serialize the content component of entry which is a tree-reference.

    :param entry: A TreeReference.

    """

    tree_revision = entry.reference_revision

    if tree_revision is None:

        raise errors.BzrError('Missing reference revision for %s' % entry.file_id)

    return "tree\x00%s" % tree_revision

def _dir_to_entry(content, name, parent_id, file_id, last_modified,

    _type=inventory.InventoryDirectory):

    """Convert a dir content record to an InventoryDirectory."""

    result = _type(file_id, name, parent_id)

    result.revision = last_modified

    return result

def _file_to_entry(content, name, parent_id, file_id, last_modified,

    _type=inventory.InventoryFile):

    """Convert a dir content record to an InventoryFile."""

    result = _type(file_id, name, parent_id)

    result.revision = last_modified

    result.text_size = int(content[1])

    result.text_sha1 = content[3]

    if content[2]:

        result.executable = True

    else:

        result.executable = False

    return result

def _link_to_entry(content, name, parent_id, file_id, last_modified,

    _type=inventory.InventoryLink):

    """Convert a link content record to an InventoryLink."""

    result = _type(file_id, name, parent_id)

    result.revision = last_modified

    result.symlink_target = content[1].decode('utf8')

    return result

def _tree_to_entry(content, name, parent_id, file_id, last_modified,

    _type=inventory.TreeReference):

    """Convert a tree content record to a TreeReference."""

    result = _type(file_id, name, parent_id)

    result.revision = last_modified

    result.reference_revision = content[1]

    return result

class InventoryDeltaSerializer(object):

    """Serialize and deserialize inventory deltas."""

    FORMAT_1 = 'bzr inventory delta v1 (bzr 1.14)'

    def __init__(self, versioned_root, tree_references):

        """Create an InventoryDeltaSerializer.

        :param versioned_root: If True, any root entry that is seen is expected

            to be versioned, and root entries can have any fileid.

        :param tree_references: If True support tree-reference entries.

        """

        self._versioned_root = versioned_root

        self._tree_references = tree_references

        self._entry_to_content = {

            'directory': _directory_content,

            'file': _file_content,

            'symlink': _link_content,

        }

        if tree_references:

            self._entry_to_content['tree-reference'] = _reference_content

    def delta_to_lines(self, old_name, new_name, delta_to_new):

        """Return a line sequence for delta_to_new.

        :param old_name: A UTF8 revision id for the old inventory.  May be

            NULL_REVISION if there is no older inventory and delta_to_new

            includes the entire inventory contents.

        :param new_name: The version name of the inventory we create with this

            delta.

        :param delta_to_new: An inventory delta such as Inventory.apply_delta

            takes.

        :return: The serialized delta as lines.

        """

        lines = ['', '', '', '', '']

        to_line = self._delta_item_to_line

        for delta_item in delta_to_new:

            lines.append(to_line(delta_item))

            if lines[-1].__class__ != str:

                raise errors.BzrError(

                    'to_line generated non-str output %r' % lines[-1])

        lines.sort()

        lines[0] = "format: %s\n" % InventoryDeltaSerializer.FORMAT_1

        lines[1] = "parent: %s\n" % old_name

        lines[2] = "version: %s\n" % new_name

        lines[3] = "versioned_root: %s\n" % self._serialize_bool(

            self._versioned_root)

        lines[4] = "tree_references: %s\n" % self._serialize_bool(

            self._tree_references)

        return lines

    def _serialize_bool(self, value):

        if value:

            return "true"

        else:

            return "false"

    def _delta_item_to_line(self, delta_item):

        """Convert delta_item to a line."""

        oldpath, newpath, file_id, entry = delta_item

        if newpath is None:

            # delete

            oldpath_utf8 = '/' + oldpath.encode('utf8')

            newpath_utf8 = 'None'

            parent_id = ''

            last_modified = NULL_REVISION

            content = 'deleted\x00\x00'

        else:

            if oldpath is None:

                oldpath_utf8 = 'None'

            else:

                oldpath_utf8 = '/' + oldpath.encode('utf8')

            # TODO: Test real-world utf8 cache hit rate. It may be a win.

            newpath_utf8 = '/' + newpath.encode('utf8')

            # Serialize None as ''

            parent_id = entry.parent_id or ''

            # Serialize unknown revisions as NULL_REVISION

            last_modified = entry.revision

            # special cases for /

            if newpath_utf8 == '/' and not self._versioned_root:

                if file_id != 'TREE_ROOT':

                    raise errors.BzrError(

                        'file_id %s is not TREE_ROOT for /' % file_id)

                if last_modified is not None:

                    raise errors.BzrError(

                        'Version present for / in %s' % file_id)

                last_modified = NULL_REVISION

            if last_modified is None:

                raise errors.BzrError("no version for fileid %s" % file_id)

            content = self._entry_to_content[entry.kind](entry)

        return ("%s\x00%s\x00%s\x00%s\x00%s\x00%s\n" %

            (oldpath_utf8, newpath_utf8, file_id, parent_id, last_modified,

                content))

    def _deserialize_bool(self, value):

        if value == "true":

            return True

        elif value == "false":

            return False

        else:

            raise errors.BzrError("value %r is not a bool" % (value,))

    def parse_text_bytes(self, bytes):

        """Parse the text bytes of a serialized inventory delta.

        :param bytes: The bytes to parse. This can be obtained by calling

            delta_to_lines and then doing ''.join(delta_lines).

        :return: (parent_id, new_id, inventory_delta)

        """

        lines = bytes.split('\n')[:-1] # discard the last empty line

        if not lines or lines[0] != 'format: %s' % InventoryDeltaSerializer.FORMAT_1:

            raise errors.BzrError('unknown format %r' % lines[0:1])

        if len(lines) < 2 or not lines[1].startswith('parent: '):

            raise errors.BzrError('missing parent: marker')

        delta_parent_id = lines[1][8:]

        if len(lines) < 3 or not lines[2].startswith('version: '):

            raise errors.BzrError('missing version: marker')

        delta_version_id = lines[2][9:]

        if len(lines) < 4 or not lines[3].startswith('versioned_root: '):

            raise errors.BzrError('missing versioned_root: marker')

        delta_versioned_root = self._deserialize_bool(lines[3][16:])

        if len(lines) < 5 or not lines[4].startswith('tree_references: '):

            raise errors.BzrError('missing tree_references: marker')

        delta_tree_references = self._deserialize_bool(lines[4][17:])

        if delta_versioned_root != self._versioned_root:

            raise errors.BzrError(

                "serialized versioned_root flag is wrong: %s" %

                (delta_versioned_root,))

        if delta_tree_references != self._tree_references:

            raise errors.BzrError(

                "serialized tree_references flag is wrong: %s" %

                (delta_tree_references,))

        result = []

        seen_ids = set()

        line_iter = iter(lines)

        for i in range(5):

            line_iter.next()

        for line in line_iter:

            (oldpath_utf8, newpath_utf8, file_id, parent_id, last_modified,

                content) = line.split('\x00', 5)

            parent_id = parent_id or None

            if file_id in seen_ids:

                raise errors.BzrError(

                    "duplicate file id in inventory delta %r" % lines)

            seen_ids.add(file_id)

            if newpath_utf8 == '/' and not delta_versioned_root and (

                last_modified != 'null:' or file_id != 'TREE_ROOT'):

                    raise errors.BzrError("Versioned root found: %r" % line)

            elif last_modified[-1] == ':':

                    raise errors.BzrError('special revisionid found: %r' % line)

            if not delta_tree_references and content.startswith('tree\x00'):

                raise errors.BzrError("Tree reference found: %r" % line)

            content_tuple = tuple(content.split('\x00'))

            entry = _parse_entry(

                newpath_utf8, file_id, parent_id, last_modified, content_tuple)

            if oldpath_utf8 == 'None':

                oldpath = None

            else:

                oldpath = oldpath_utf8.decode('utf8')

            if newpath_utf8 == 'None':

                newpath = None

            else:

                newpath = newpath_utf8.decode('utf8')

            delta_item = (oldpath, newpath, file_id, entry)

            result.append(delta_item)

        return delta_parent_id, delta_version_id, result

def _parse_entry(utf8_path, file_id, parent_id, last_modified, content):

    entry_factory = {

        'dir': _dir_to_entry,

        'file': _file_to_entry,

        'link': _link_to_entry,

        'tree': _tree_to_entry,

    }

    kind = content[0]

    path = utf8_path[1:].decode('utf8')

    name = basename(path)

    return entry_factory[content[0]](

            content, name, parent_id, file_id, last_modified)