~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 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 cStringIO

import re

from bzrlib import (

    cache_utf8,

    inventory,

    )

from bzrlib.xml_serializer import SubElement, Element, Serializer

from bzrlib.inventory import ROOT_ID, Inventory, InventoryEntry

from bzrlib.revision import Revision

from bzrlib.errors import BzrError

_utf8_re = None

_utf8_escape_map = {

    "&":'&',

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

    "\"":""",

    "<":"&lt;",

    ">":">",

    }

def _ensure_utf8_re():

    """Make sure the _utf8_re regex has been compiled"""

    global _utf8_re

    if _utf8_re is not None:

        return

    _utf8_re = re.compile(u'[&<>\'\"\u0080-\uffff]')

def _utf8_escape_replace(match, _map=_utf8_escape_map):

    """Replace a string of non-ascii, non XML safe characters with their escape

    This will escape both Standard XML escapes, like <>"', etc.

    As well as escaping non ascii characters, because ElementTree did.

    This helps us remain compatible to older versions of bzr. We may change

    our policy in the future, though.

    """

    # TODO: jam 20060816 Benchmark this, is it better to use try/except or

    #       to use _map.get() and check for None.

    #       Or still further, it might be better to pre-generate all

    #       possible conversions. However, the occurance of unicode

    #       characters is quite low, so an initial guess is that this

    #       is the most efficient method

    #       Also need to benchmark whether it is better to have a regex

    #       which matches multiple characters, or if it is better to

    #       only match a single character and call this function multiple

    #       times. The chance that we actually need multiple escapes

    #       is probably very low for our expected usage

    try:

        return _map[match.group()]

    except KeyError:

        return "&#%d;" % ord(match.group())

_unicode_to_escaped_map = {}

def _encode_and_escape(unicode_str, _map=_unicode_to_escaped_map):

    """Encode the string into utf8, and escape invalid XML characters"""

    text = _map.get(unicode_str)

    if text is None:

        # The alternative policy is to do a regular UTF8 encoding

        # and then escape only XML meta characters. This could take

        # advantage of cache_utf8 since a lot of the revision ids

        # and file ids would already be cached.

        text = str(_utf8_re.sub(_utf8_escape_replace, unicode_str))

        _map[unicode_str] = text

    return text

def _clear_cache():

    """Clean out the unicode => escaped map"""

    _unicode_to_escaped_map.clear()

class Serializer_v5(Serializer):

    """Version 5 serializer

    Packs objects into XML and vice versa.

    """

    __slots__ = []

    def write_inventory_to_string(self, inv):

        """Just call write_inventory with a StringIO and return the value"""

        sio = cStringIO.StringIO()

        self.write_inventory(inv, sio)

        return sio.getvalue()

    def write_inventory(self, inv, f):

        """Write inventory to a file.

        :param inv: the inventory to write.

        :param f: the file to write.

        """

        _ensure_utf8_re()

        output = []

        self._append_inventory_root(output, inv)

        entries = inv.iter_entries()

        # Skip the root

        root_path, root_ie = entries.next()

        for path, ie in entries:

            self._append_entry(output, ie)

        output.append('</inventory>\n')

        f.writelines(output)

        # Just to keep the cache from growing without bounds

        # but we may actually not want to do clear the cache

        _clear_cache()

    def _append_inventory_root(self, output, inv):

        """Append the inventory root to output."""

        output.append('<inventory')

        if inv.root.file_id not in (None, ROOT_ID):

            output.append(' file_id="')

            self._append_utf8_escaped(output, inv.root.file_id)

        output.append(' format="5"')

        if inv.revision_id is not None:

            output.append(' revision_id="')

            self._append_utf8_escaped(output, inv.revision_id)

        output.append('>\n')

    def _append_entry(self, output, ie):

        """Convert InventoryEntry to XML element and append to output."""

        # TODO: should just be a plain assertion

        assert InventoryEntry.versionable_kind(ie.kind), \

            'unsupported entry kind %s' % ie.kind

        output.append("<")

        output.append(ie.kind)

        if ie.executable:

            output.append(' executable="yes"')

        output.append(' file_id="')

        self._append_utf8_escaped(output, ie.file_id)

        output.append(' name="')

        self._append_utf8_escaped(output, ie.name)

        if ie.parent_id != ROOT_ID:

            assert isinstance(ie.parent_id, basestring)

            output.append(' parent_id="')

            self._append_utf8_escaped(output, ie.parent_id)

        if ie.revision is not None:

            output.append(' revision="')

            self._append_utf8_escaped(output, ie.revision)

        if ie.symlink_target is not None:

            output.append(' symlink_target="')

            self._append_utf8_escaped(output, ie.symlink_target)

        if ie.text_sha1 is not None:

            output.append(' text_size="')

            output.append(ie.text_sha1)

            output.append('"')

        if ie.text_size is not None:

            output.append(' text_size="%d"' % ie.text_size)

        output.append(" />\n")

        return

    def _append_utf8_escaped(self, output, a_string):

        """Append a_string to output as utf8."""

        output.append(_encode_and_escape(a_string))

        output.append('"')

    def _pack_inventory(self, inv):

        """Convert to XML Element"""

        entries = inv.iter_entries()

        e = Element('inventory',

                    format='5')

        e.text = '\n'

        path, root = entries.next()

        if root.file_id not in (None, ROOT_ID):

            e.set('file_id', root.file_id)

        if inv.revision_id is not None:

            e.set('revision_id', inv.revision_id)

        for path, ie in entries:

            e.append(self._pack_entry(ie))

        return e

    def _pack_entry(self, ie):

        """Convert InventoryEntry to XML element"""

        # TODO: should just be a plain assertion

        if not InventoryEntry.versionable_kind(ie.kind):

            raise AssertionError('unsupported entry kind %s' % ie.kind)

        e = Element(ie.kind)

        e.set('name', ie.name)

        e.set('file_id', ie.file_id)

        if ie.text_size != None:

            e.set('text_size', '%d' % ie.text_size)

        for f in ['text_sha1', 'revision', 'symlink_target']:

            v = getattr(ie, f)

            if v != None:

                e.set(f, v)

        if ie.executable:

            e.set('executable', 'yes')

        # to be conservative, we don't externalize the root pointers

        # for now, leaving them as null in the xml form.  in a future

        # version it will be implied by nested elements.

        if ie.parent_id != ROOT_ID:

            assert isinstance(ie.parent_id, basestring)

            e.set('parent_id', ie.parent_id)

        e.tail = '\n'

        return e

    def _pack_revision(self, rev):

        """Revision object -> xml tree"""

        root = Element('revision',

                       committer = rev.committer,

                       timestamp = '%.9f' % rev.timestamp,

                       revision_id = rev.revision_id,

                       inventory_sha1 = rev.inventory_sha1,

                       format='5',

                       )

        if rev.timezone is not None:

            root.set('timezone', str(rev.timezone))

        root.text = '\n'

        msg = SubElement(root, 'message')

        msg.text = rev.message

        msg.tail = '\n'

        if rev.parent_ids:

            pelts = SubElement(root, 'parents')

            pelts.tail = pelts.text = '\n'

            for parent_id in rev.parent_ids:

                assert isinstance(parent_id, basestring)

                p = SubElement(pelts, 'revision_ref')

                p.tail = '\n'

                p.set('revision_id', parent_id)

        if rev.properties:

            self._pack_revision_properties(rev, root)

        return root

    def _pack_revision_properties(self, rev, under_element):

        top_elt = SubElement(under_element, 'properties')

        for prop_name, prop_value in sorted(rev.properties.items()):

            assert isinstance(prop_name, basestring) 

            assert isinstance(prop_value, basestring) 

            prop_elt = SubElement(top_elt, 'property')

            prop_elt.set('name', prop_name)

            prop_elt.text = prop_value

            prop_elt.tail = '\n'

        top_elt.tail = '\n'

    def _unpack_inventory(self, elt):

        """Construct from XML Element

        """

        assert elt.tag == 'inventory'

        root_id = elt.get('file_id') or ROOT_ID

        format = elt.get('format')

        if format is not None:

            if format != '5':

                raise BzrError("invalid format version %r on inventory"

                                % format)

        revision_id = elt.get('revision_id')

        if revision_id is not None:

            revision_id = cache_utf8.get_cached_unicode(revision_id)

        inv = Inventory(root_id, revision_id=revision_id)

        for e in elt:

            ie = self._unpack_entry(e)

            if ie.parent_id == ROOT_ID:

                ie.parent_id = root_id

            inv.add(ie)

        return inv

    def _unpack_entry(self, elt):

        kind = elt.tag

        if not InventoryEntry.versionable_kind(kind):

            raise AssertionError('unsupported entry kind %s' % kind)

        get_cached = cache_utf8.get_cached_unicode

        parent_id = elt.get('parent_id')

        if parent_id == None:

            parent_id = ROOT_ID

        parent_id = get_cached(parent_id)

        file_id = get_cached(elt.get('file_id'))

        if kind == 'directory':

            ie = inventory.InventoryDirectory(file_id,

                                              elt.get('name'),

                                              parent_id)

        elif kind == 'file':

            ie = inventory.InventoryFile(file_id,

                                         elt.get('name'),

                                         parent_id)

            ie.text_sha1 = elt.get('text_sha1')

            if elt.get('executable') == 'yes':

                ie.executable = True

            v = elt.get('text_size')

            ie.text_size = v and int(v)

        elif kind == 'symlink':

            ie = inventory.InventoryLink(file_id,

                                         elt.get('name'),

                                         parent_id)

            ie.symlink_target = elt.get('symlink_target')

        else:

            raise BzrError("unknown kind %r" % kind)

        revision = elt.get('revision')

        if revision is not None:

            revision = get_cached(revision)

        ie.revision = revision

        return ie

    def _unpack_revision(self, elt):

        """XML Element -> Revision object"""

        assert elt.tag == 'revision'

        format = elt.get('format')

        if format is not None:

            if format != '5':

                raise BzrError("invalid format version %r on inventory"

                                % format)

        get_cached = cache_utf8.get_cached_unicode

        rev = Revision(committer = elt.get('committer'),

                       timestamp = float(elt.get('timestamp')),

                       revision_id = get_cached(elt.get('revision_id')),

                       inventory_sha1 = elt.get('inventory_sha1')

                       )

        parents = elt.find('parents') or []

        for p in parents:

            assert p.tag == 'revision_ref', \

                   "bad parent node tag %r" % p.tag

            rev.parent_ids.append(get_cached(p.get('revision_id')))

        self._unpack_revision_properties(elt, rev)

        v = elt.get('timezone')

        if v is None:

            rev.timezone = 0

        else:

            rev.timezone = int(v)

        rev.message = elt.findtext('message') # text of <message>

        return rev

    def _unpack_revision_properties(self, elt, rev):

        """Unpack properties onto a revision."""

        props_elt = elt.find('properties')

        assert len(rev.properties) == 0

        if not props_elt:

            return

        for prop_elt in props_elt:

            assert prop_elt.tag == 'property', \

                "bad tag under properties list: %r" % prop_elt.tag

            name = prop_elt.get('name')

            value = prop_elt.text

            # If a property had an empty value ('') cElementTree reads

            # that back as None, convert it back to '', so that all

            # properties have string values

            if value is None:

                value = ''

            assert name not in rev.properties, \

                "repeated property %r" % name

            rev.properties[name] = value

serializer_v5 = Serializer_v5()