~bzr-pqm/bzr/bzr.dev

# -*- coding: UTF-8 -*-

#

# 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

"""XML externalization support."""

# "XML is like violence: if it doesn't solve your problem, you aren't

# using enough of it." -- various

# importing this module is fairly slow because it has to load several

# ElementTree bits

from bzrlib.trace import mutter, warning

try:

    from cElementTree import (ElementTree, SubElement, Element,

                              XMLTreeBuilder, fromstring, tostring)

    import elementtree

except ImportError:

    mutter('WARNING: using slower ElementTree; consider installing cElementTree'

           " and make sure it's on your PYTHONPATH")

    from util.elementtree.ElementTree import (ElementTree, SubElement,

                                              Element, XMLTreeBuilder,

                                              fromstring, tostring)

    import util.elementtree as elementtree

from bzrlib import errors

class Serializer(object):

    """Abstract object serialize/deserialize"""

    def write_inventory(self, inv, f):

        """Write inventory to a file"""

        elt = self._pack_inventory(inv)

        self._write_element(elt, f)

    def write_inventory_to_string(self, inv):

        return tostring(self._pack_inventory(inv)) + '\n'

    def read_inventory_from_string(self, xml_string):

        try:

            return self._unpack_inventory(fromstring(xml_string))

        except SyntaxError, e:

            raise errors.UnexpectedInventoryFormat(e)

    def read_inventory(self, f):

        try:

            return self._unpack_inventory(self._read_element(f))

        except SyntaxError, e:

            raise errors.UnexpectedInventoryFormat(e)

    def write_revision(self, rev, f):

        self._write_element(self._pack_revision(rev), f)

    def write_revision_to_string(self, rev):

        return tostring(self._pack_revision(rev)) + '\n'

    def read_revision(self, f):

        return self._unpack_revision(self._read_element(f))

    def read_revision_from_string(self, xml_string):

        return self._unpack_revision(fromstring(xml_string))

    def _write_element(self, elt, f):

        ElementTree(elt).write(f, 'utf-8')

        f.write('\n')

    def _read_element(self, f):

        return ElementTree().parse(f)

# performance tuning for elementree's serialiser. This should be

# sent upstream - RBC 20060523.

# the functions here are patched into elementtree at runtime.

import re

escape_re = re.compile("[&'\"<>]")

escape_map = {

    "&":'&',

    "'":"'", # FIXME: overkill

    "\"":""",

    "<":"&lt;",

    ">":">",

    }

def _escape_replace(match, map=escape_map):

    return map[match.group()]

def _escape_attrib(text, encoding=None, replace=None):

    # escape attribute value

    try:

        if encoding:

            try:

                text = elementtree.ElementTree._encode(text, encoding)

            except UnicodeError:

                return elementtree.ElementTree._encode_entity(text)

        if replace is None:

            return escape_re.sub(_escape_replace, text)

        else:

            text = replace(text, "&", "&")

            text = replace(text, "'", "'") # FIXME: overkill

            text = replace(text, "\"", """)

            text = replace(text, "<", "&lt;")

            text = replace(text, ">", ">")

            return text

    except (TypeError, AttributeError):

        elementtree.ElementTree._raise_serialization_error(text)

elementtree.ElementTree._escape_attrib = _escape_attrib

escape_cdata_re = re.compile("[&<>]")

escape_cdata_map = {

    "&":'&',

    "<":"&lt;",

    ">":">",

    }

def _escape_cdata_replace(match, map=escape_cdata_map):

    return map[match.group()]

def _escape_cdata(text, encoding=None, replace=None):

    # escape character data

    try:

        if encoding:

            try:

                text = elementtree.ElementTree._encode(text, encoding)

            except UnicodeError:

                return elementtree.ElementTree._encode_entity(text)

        if replace is None:

            return escape_cdata_re.sub(_escape_cdata_replace, text)

        else:

            text = replace(text, "&", "&")

            text = replace(text, "<", "&lt;")

            text = replace(text, ">", ">")

            return text

    except (TypeError, AttributeError):

        elementtree.ElementTree._raise_serialization_error(text)

elementtree.ElementTree._escape_cdata = _escape_cdata