virt-manager/virtinst/xmlbuilder.py

1094 lines
36 KiB
Python

#
# Base class for all VM devices
#
# Copyright 2008, 2013 Red Hat, Inc.
# Cole Robinson <crobinso@redhat.com>
#
# 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.
import copy
import logging
import os
import re
import libxml2
from . import util
# pylint: disable=protected-access
# This whole file is calling around into non-public functions that we
# don't want regular API users to touch
_trackprops = bool("VIRTINST_TEST_SUITE" in os.environ)
_allprops = []
_seenprops = []
class _DocCleanupWrapper(object):
def __init__(self, doc):
self._doc = doc
def __del__(self):
self._doc.freeDoc()
class _CtxCleanupWrapper(object):
def __init__(self, ctx):
self._ctx = ctx
def __del__(self):
self._ctx.xpathFreeContext()
self._ctx = None
def __getattr__(self, attrname):
return getattr(self._ctx, attrname)
def _make_xml_context(node):
doc = node.doc
ctx = _CtxCleanupWrapper(doc.xpathNewContext())
ctx.setContextNode(node)
return ctx
def _tuplify_lists(*args):
"""
Similar to zip(), but use None if lists aren't long enough, and
don't skip any None list entry
"""
args = [util.listify(l) for l in args]
maxlen = max([len(l) for l in args])
ret = []
for idx in range(maxlen):
tup = tuple()
for l in args:
tup += (idx >= len(l) and (None,) or (l[idx],))
ret.append(tup)
return ret
def _sanitize_libxml_xml(xml):
# Strip starting <?...> line
if xml.startswith("<?"):
ignore, xml = xml.split("\n", 1)
if not xml.endswith("\n") and xml.count("\n"):
xml += "\n"
return xml
def _get_xpath_node(ctx, xpath):
node = ctx.xpathEval(xpath)
return (node and node[0] or None)
def _build_xpath_node(ctx, xpath, addnode=None):
"""
Build all nodes required to set an xpath. If we have XML <foo/>, and want
to set xpath /foo/bar/baz@booyeah, we create node 'bar' and 'baz'
returning the last node created.
"""
parentpath = ""
parentnode = None
def prevSibling(node):
parent = node.get_parent()
if not parent:
return None
prev = None
for child in parent.children:
if child == node:
return prev
prev = child
return None
def make_node(parentnode, newnode):
# Add the needed parent node, try to preserve whitespace by
# looking for a starting TEXT node, and copying it
def node_is_text(n):
return bool(n and n.type == "text" and not n.content.count("<"))
sib = parentnode.get_last()
if not node_is_text(sib):
# This case is when we add a child element to a node for the
# first time, like:
#
# <features/>
# to
# <features>
# <acpi/>
# </features>
prevsib = prevSibling(parentnode)
if node_is_text(prevsib):
sib = libxml2.newText(prevsib.content)
else:
sib = libxml2.newText("\n")
parentnode.addChild(sib)
# This case is adding a child element to an already properly
# spaced element. Example:
# <features>
# <acpi/>
# </features>
# to
# <features>
# <acpi/>
# <apic/>
# </features>
sib = parentnode.get_last()
content = sib.content
sib = sib.addNextSibling(libxml2.newText(" "))
txt = libxml2.newText(content)
sib.addNextSibling(newnode)
newnode.addNextSibling(txt)
return newnode
nodelist = xpath.split("/")
for idx in range(len(nodelist)):
nodename = nodelist[idx]
if not nodename:
continue
# If xpath is a node property, set it and move on
if nodename.startswith("@"):
nodename = nodename.strip("@")
parentnode = parentnode.setProp(nodename, "")
continue
if not parentpath:
parentpath = nodename
else:
parentpath += "/%s" % nodename
# Node found, nothing to create for now
node = _get_xpath_node(ctx, parentpath)
if node:
parentnode = node
continue
if not parentnode:
raise RuntimeError("Could not find XML root node")
# Remove conditional xpath elements for node creation
if nodename.count("["):
nodename = nodename[:nodename.index("[")]
newnode = libxml2.newNode(nodename)
parentnode = make_node(parentnode, newnode)
if addnode:
parentnode = make_node(parentnode, addnode)
return parentnode
def _remove_xpath_node(ctx, xpath, dofree=True):
"""
Remove an XML node tree if it has no content
"""
curxpath = xpath
root_node = ctx.contextNode()
while curxpath:
is_orig = (curxpath == xpath)
node = _get_xpath_node(ctx, curxpath)
if curxpath.count("/"):
curxpath, ignore = curxpath.rsplit("/", 1)
else:
curxpath = None
if not node:
continue
if node.type not in ["attribute", "element"]:
continue
if node.type == "element" and (node.children or node.properties):
# Only do a deep unlink if it was the original requested path
if not is_orig:
continue
# Look for preceding whitespace and remove it
white = node.get_prev()
if white and white.type == "text" and not white.content.count("<"):
white.unlinkNode()
white.freeNode()
if node == root_node:
# Don't unlink the root node, since it's spread out to all
# child objects and it ends up wreaking havoc.
break
node.unlinkNode()
if dofree:
node.freeNode()
class XMLChildProperty(property):
"""
Property that points to a class used for parsing a subsection of
of the parent XML. For example when we deligate parsing
/domain/cpu/feature of the /domain/cpu class.
@child_classes: Single class or list of classes to parse state into
@relative_xpath: Relative location where the class is rooted compared
to its _XML_ROOT_PATH. So interface xml can have nested
interfaces rooted at /interface/bridge/interface, so we pass
./bridge/interface here for example.
"""
def __init__(self, child_classes, relative_xpath=".", is_single=False):
self.child_classes = util.listify(child_classes)
self.relative_xpath = relative_xpath
self.is_single = is_single
self._propname = None
if self.is_single and len(self.child_classes) > 1:
raise RuntimeError("programming error: Can't specify multiple "
"child_classes with is_single")
property.__init__(self, self._fget)
def __repr__(self):
return "<XMLChildProperty %s %s>" % (str(self.child_classes), id(self))
def _findpropname(self, xmlbuilder):
if self._propname is None:
for key, val in xmlbuilder._all_child_props().items():
if val is self:
self._propname = key
break
if self._propname is None:
raise RuntimeError("Didn't find expected property=%s" % self)
return self._propname
def _get(self, xmlbuilder):
propname = self._findpropname(xmlbuilder)
if propname not in xmlbuilder._propstore and not self.is_single:
xmlbuilder._propstore[propname] = []
return xmlbuilder._propstore[propname]
def _fget(self, xmlbuilder):
if self.is_single:
return self._get(xmlbuilder)
return self._get(xmlbuilder)[:]
def clear(self, xmlbuilder):
if self.is_single:
self._get(xmlbuilder).clear()
else:
for obj in self._get(xmlbuilder)[:]:
xmlbuilder._remove_child(obj)
def append(self, xmlbuilder, newobj):
# Keep the list ordered by the order of passed in child classes
objlist = self._get(xmlbuilder)
if len(self.child_classes) == 1:
objlist.append(newobj)
return
idx = 0
for idx in range(len(objlist)):
obj = objlist[idx]
if (obj.__class__ not in self.child_classes or
(self.child_classes.index(newobj.__class__) <
self.child_classes.index(obj.__class__))):
break
idx += 1
objlist.insert(idx, newobj)
def remove(self, xmlbuilder, obj):
self._get(xmlbuilder).remove(obj)
def set(self, xmlbuilder, obj):
xmlbuilder._propstore[self._findpropname(xmlbuilder)] = obj
def get_prop_xpath(self, xmlbuilder, obj):
relative_xpath = self.relative_xpath + "/" + obj._XML_ROOT_NAME
match = re.search("%\((.*)\)", self.relative_xpath)
if match:
valuedict = {}
for paramname in match.groups():
valuedict[paramname] = getattr(xmlbuilder, paramname)
relative_xpath = relative_xpath % valuedict
return relative_xpath
class XMLProperty(property):
_track = True
def __init__(self, xpath=None, name=None, doc=None,
set_converter=None, validate_cb=None, make_xpath_cb=None,
is_bool=False, is_int=False, is_yesno=False, is_onoff=False,
clear_first=None, default_cb=None, default_name=None,
do_abspath=False):
"""
Set a XMLBuilder class property that represents a value in the
<domain> XML. For example
name = XMLProperty(get_name, set_name, xpath="/domain/name")
When building XML from scratch (virt-install), name is a regular
class property. When parsing and editting existing guest XML, we
use the xpath value to map the name property to the underlying XML
definition.
@param doc: option doc string for the property
@param xpath: xpath string which maps to the associated property
in a typical XML document
@param name: Just a string to print for debugging, only needed
if xpath isn't specified.
@param set_converter: optional function for converting the property
value from the virtinst API to the guest XML. For example,
the Guest.memory API was once in MiB, but the libvirt domain
memory API is in KiB. So, if xpath is specified, on a 'get'
operation we convert the XML value with int(val) / 1024.
@param validate_cb: Called once when value is set, should
raise a RuntimeError if the value is not proper.
@param make_xpath_cb: Not all props map cleanly to a
static xpath. This allows passing functions which generate
an xpath.
@param is_bool: Whether this is a boolean property in the XML
@param is_int: Whether this is an integer property in the XML
@param is_yesno: Whether this is a yes/no property in the XML
@param is_onoff: Whether this is an on/off property in the XML
@param clear_first: List of xpaths to unset before any 'set' operation.
For those weird interdependent XML props like disk source type and
path attribute.
@param default_cb: If building XML from scratch, and this property
is never explicitly altered, this function is called for setting
a default value in the XML, and for any 'get' call before the
first explicit 'set'.
@param default_name: If the user does a set and passes in this
value, instead use the value of default_cb()
@param do_abspath: If True, run os.path.abspath on the passed value
"""
self._xpath = xpath
self._name = name or xpath
if not self._name:
raise RuntimeError("XMLProperty: name or xpath must be passed.")
self._propname = None
self._is_bool = is_bool
self._is_int = is_int
self._is_yesno = is_yesno
self._is_onoff = is_onoff
self._do_abspath = do_abspath
self._make_xpath_cb = make_xpath_cb
self._validate_cb = validate_cb
self._convert_value_for_setter_cb = set_converter
self._setter_clear_these_first = clear_first or []
self._default_cb = default_cb
self._default_name = default_name
if sum([int(bool(i)) for i in
[self._is_bool, self._is_int,
self._is_yesno, self._is_onoff]]) > 1:
raise RuntimeError("Conflict property converter options.")
if self._default_name and not self._default_cb:
raise RuntimeError("default_name requires default_cb.")
if _trackprops and self._track:
_allprops.append(self)
property.__init__(self, fget=self.getter, fset=self.setter)
self.__doc__ = doc
def __repr__(self):
return "<XMLProperty %s %s>" % (str(self._name), id(self))
####################
# Internal helpers #
####################
def _findpropname(self, xmlbuilder):
"""
Map the raw property() instance to the param name it's exposed
as in the XMLBuilder class. This is just for debug purposes.
"""
if self._propname is None:
for key, val in xmlbuilder._all_xml_props().items():
if val is self:
self._propname = key
break
if self._propname is None:
raise RuntimeError("Didn't find expected property=%s" % self)
return self._propname
def _make_xpath(self, xmlbuilder):
ret = self._xpath
if self._make_xpath_cb:
ret = self._make_xpath_cb(xmlbuilder)
if ret is None:
raise RuntimeError("%s: didn't generate any xpath." % self)
return xmlbuilder.fix_relative_xpath(ret)
def _build_node_list(self, xmlbuilder, xpath):
"""
Build list of nodes that the passed xpaths reference
"""
nodes = _get_xpath_node(xmlbuilder._xmlstate.xml_ctx, xpath)
return util.listify(nodes)
def _build_clear_list(self, xmlbuilder, setternode):
"""
Build a list of nodes that we should erase first before performing
a set operation. But we don't want to unset a node that we are
just going to 'set' on top of afterwards, so skip those ones.
"""
clear_nodes = []
for cpath in self._setter_clear_these_first:
cpath = xmlbuilder.fix_relative_xpath(cpath)
cnode = _get_xpath_node(xmlbuilder._xmlstate.xml_ctx, cpath)
if not cnode:
continue
if setternode and setternode.nodePath() == cnode.nodePath():
continue
clear_nodes.append(cnode)
return clear_nodes
def _convert_get_value(self, val):
if self._default_name and val == self._default_name:
ret = val
elif self._is_bool:
ret = bool(val)
elif self._is_int and val is not None:
intkwargs = {}
if "0x" in str(val):
intkwargs["base"] = 16
ret = int(val, **intkwargs)
elif self._is_yesno and val is not None:
ret = bool(val == "yes")
elif self._is_onoff and val is not None:
ret = bool(val == "on")
else:
ret = val
return ret
def _convert_set_value(self, xmlbuilder, val):
if self._default_name and val == self._default_name:
val = self._default_cb(xmlbuilder)
elif self._do_abspath and val is not None:
val = os.path.abspath(val)
elif self._is_onoff and val is not None:
val = bool(val) and "on" or "off"
elif self._is_yesno and val is not None:
val = bool(val) and "yes" or "no"
elif self._is_int and val is not None:
intkwargs = {}
if "0x" in str(val):
intkwargs["base"] = 16
val = int(val, **intkwargs)
if self._convert_value_for_setter_cb:
val = self._convert_value_for_setter_cb(xmlbuilder, val)
return val
def _prop_is_unset(self, xmlbuilder):
propname = self._findpropname(xmlbuilder)
return (propname not in xmlbuilder._propstore)
def _default_get_value(self, xmlbuilder):
"""
Return (can use default, default value)
"""
ret = (False, -1)
if not xmlbuilder._xmlstate.is_build:
return ret
if not self._prop_is_unset(xmlbuilder):
return ret
if not self._default_cb:
return ret
if self._default_name:
return (True, self._default_name)
return (True, self._default_cb(xmlbuilder))
def _set_default(self, xmlbuilder):
"""
Encode the property default into the XML and propstore, but
only if a default is registered, and only if the property was
not already explicitly set by the API user.
This is called during the get_xml_config process and shouldn't
be called from outside this file.
"""
candefault, val = self._default_get_value(xmlbuilder)
if not candefault:
return
self.setter(xmlbuilder, val, validate=False)
def _nonxml_fset(self, xmlbuilder, val):
"""
This stores the value in XMLBuilder._propstore
dict as propname->value. This saves us from having to explicitly
track every variable.
"""
propstore = xmlbuilder._propstore
proporder = xmlbuilder._proporder
if _trackprops and self not in _seenprops:
_seenprops.append(self)
propname = self._findpropname(xmlbuilder)
propstore[propname] = val
if propname in proporder:
proporder.remove(propname)
proporder.append(propname)
def _nonxml_fget(self, xmlbuilder):
"""
The flip side to nonxml_fset, fetch the value from
XMLBuilder._propstore
"""
candefault, val = self._default_get_value(xmlbuilder)
if candefault:
return val
propname = self._findpropname(xmlbuilder)
return xmlbuilder._propstore.get(propname, None)
def clear(self, xmlbuilder):
self.setter(xmlbuilder, None)
self._set_xml(xmlbuilder, None)
##################################
# The actual getter/setter impls #
##################################
def getter(self, xmlbuilder):
"""
Fetch value at user request. If we are parsing existing XML and
the user hasn't done a 'set' yet, return the value from the XML,
otherwise return the value from propstore
If this is a built from scratch object, we never pull from XML
since it's known to the empty, and we may want to return
a 'default' value
"""
if (self._prop_is_unset(xmlbuilder) and
not xmlbuilder._xmlstate.is_build):
val = self._get_xml(xmlbuilder)
else:
val = self._nonxml_fget(xmlbuilder)
ret = self._convert_get_value(val)
return ret
def _get_xml(self, xmlbuilder):
"""
Actually fetch the associated value from the backing XML
"""
xpath = self._make_xpath(xmlbuilder)
node = _get_xpath_node(xmlbuilder._xmlstate.xml_ctx, xpath)
if not node:
return None
content = node.content
if self._is_bool:
content = True
return content
def setter(self, xmlbuilder, val, validate=True):
"""
Set the value at user request. This just stores the value
in propstore. Setting the actual XML is only done at
get_xml_config time.
"""
if validate and self._validate_cb:
self._validate_cb(xmlbuilder, val)
self._nonxml_fset(xmlbuilder,
self._convert_set_value(xmlbuilder, val))
def _set_xml(self, xmlbuilder, setval, root_node=None):
"""
Actually set the passed value in the XML document
"""
if root_node is None:
root_node = xmlbuilder._xmlstate.xml_node
ctx = xmlbuilder._xmlstate.xml_ctx
else:
ctx = _make_xml_context(root_node)
xpath = self._make_xpath(xmlbuilder)
node = _get_xpath_node(xmlbuilder._xmlstate.xml_ctx, xpath)
clearlist = self._build_clear_list(xmlbuilder, node)
node_map = []
if clearlist:
node_map += _tuplify_lists(clearlist, None,
[n.nodePath() for n in clearlist])
node_map += [(node, setval, xpath)]
for node, val, use_xpath in node_map:
if val is None or val is False:
_remove_xpath_node(ctx, use_xpath)
continue
if not node:
node = _build_xpath_node(root_node, use_xpath)
if val is True:
# Boolean property, creating the node is enough
continue
node.setContent(util.xml_escape(str(val)))
class _XMLState(object):
def __init__(self, root_name, parsexml, parsexmlnode,
parent_xpath, relative_object_xpath):
self.root_name = root_name
self.stub_path = "/%s" % self.root_name
self.xml_ctx = None
self.xml_node = None
self.xml_root_doc = None
# xpath of this object relative to its parent. So for a standalone
# <disk> this is empty, but if the disk is the forth one in a <domain>
# it will be set to ./devices/disk[4]
self._relative_object_xpath = relative_object_xpath or ""
# xpath of the parent. For a disk in a standalone <domain>, this
# is empty, but if the <domain> is part of a <domainsnapshot>,
# it will be "./domain"
self._parent_xpath = parent_xpath or ""
self.is_build = False
if not parsexml and not parsexmlnode:
self.is_build = True
self._parse(parsexml, parsexmlnode)
def _parse(self, xml, node):
if node:
self.xml_root_doc = None
self.xml_node = node
self.is_build = (getattr(node, "virtinst_is_build", False) or
self.is_build)
else:
if not xml:
xml = self.make_xml_stub()
try:
doc = libxml2.parseDoc(xml)
except:
logging.debug("Error parsing xml=\n%s", xml)
raise
self.xml_root_doc = _DocCleanupWrapper(doc)
self.xml_node = doc.children
self.xml_node.virtinst_is_build = self.is_build
self.xml_node.virtinst_node_top_xpath = self.stub_path
# This just stores a reference to our root doc wrapper in
# the root node, so when the node goes away it triggers
# auto free'ing of the doc
self.xml_node.virtinst_root_doc = self.xml_root_doc
self.xml_ctx = _make_xml_context(self.xml_node)
def make_xml_stub(self):
return "<%s/>" % self.root_name
def set_relative_object_xpath(self, xpath):
self._relative_object_xpath = xpath or ""
def set_parent_xpath(self, xpath):
self._parent_xpath = xpath or ""
def get_root_xpath(self):
relpath = self._relative_object_xpath
if not self._parent_xpath:
return relpath
return self._parent_xpath + (relpath.startswith(".") and
relpath[1:] or relpath)
def fix_relative_xpath(self, xpath):
fullpath = self.get_root_xpath()
if not fullpath or fullpath == self.stub_path:
return xpath
if xpath.startswith("."):
return "%s%s" % (fullpath, xpath.strip("."))
if xpath.count("/") == 1:
return fullpath
return fullpath + "/" + xpath.split("/", 2)[2]
def get_node_top_xpath(self):
"""
Return the XML path of the root xml_node
"""
return self.xml_node.virtinst_node_top_xpath
def get_node_xml(self, ctx):
node = _get_xpath_node(ctx, self.fix_relative_xpath("."))
if not node:
return ""
return _sanitize_libxml_xml(node.serialize())
class XMLBuilder(object):
"""
Base for all classes which build or parse domain XML
"""
# Order that we should apply values to the XML. Keeps XML generation
# consistent with what the test suite expects.
_XML_PROP_ORDER = []
# Name of the root XML element
_XML_ROOT_NAME = None
def __init__(self, conn, parsexml=None, parsexmlnode=None,
parent_xpath=None, relative_object_xpath=None):
"""
Initialize state
@param conn: libvirt connection to validate device against
@type conn: VirtualConnection
@param parsexml: Optional XML string to parse
@type parsexml: C{str}
The rest of the parameters are for internal use only
"""
self.conn = conn
self._propstore = {}
self._proporder = []
self._xmlstate = _XMLState(self._XML_ROOT_NAME,
parsexml, parsexmlnode,
parent_xpath, relative_object_xpath)
self._initial_child_parse()
def _initial_child_parse(self):
# Walk the XML tree and hand of parsing to any registered
# child classes
for xmlprop in self._all_child_props().values():
if xmlprop.is_single:
child_class = xmlprop.child_classes[0]
prop_path = xmlprop.get_prop_xpath(self, child_class)
obj = child_class(self.conn,
parsexmlnode=self._xmlstate.xml_node,
parent_xpath=self.get_root_xpath(),
relative_object_xpath=prop_path)
xmlprop.set(self, obj)
continue
if self._xmlstate.is_build:
continue
for child_class in xmlprop.child_classes:
prop_path = xmlprop.get_prop_xpath(self, child_class)
nodecount = int(self._xmlstate.xml_node.xpathEval(
"count(%s)" % self.fix_relative_xpath(prop_path)))
for idx in range(nodecount):
idxstr = "[%d]" % (idx + 1)
obj = child_class(self.conn,
parsexmlnode=self._xmlstate.xml_node,
parent_xpath=self.get_root_xpath(),
relative_object_xpath=(prop_path + idxstr))
xmlprop.append(self, obj)
self._set_child_xpaths()
########################
# Public XML Internals #
########################
def copy(self):
"""
Do a shallow copy of the device
"""
ret = copy.copy(self)
ret._propstore = ret._propstore.copy()
ret._proporder = ret._proporder[:]
# XMLChildProperty stores a list in propstore, which dict shallow
# copy won't fix for us.
for name, value in ret._propstore.items():
if type(value) is not list:
continue
ret._propstore[name] = [obj.copy() for obj in ret._propstore[name]]
return ret
def get_root_xpath(self):
return self._xmlstate.get_root_xpath()
def fix_relative_xpath(self, xpath):
return self._xmlstate.fix_relative_xpath(xpath)
############################
# Public XML managing APIs #
############################
def get_xml_config(self):
"""
Return XML string of the object
"""
data = self._prepare_get_xml()
try:
return self._do_get_xml_config()
finally:
self._finish_get_xml(data)
def clear(self):
"""
Wipe out all properties of the object
"""
props = self._all_xml_props().values()
props += self._all_child_props().values()
for prop in props:
prop.clear(self)
_remove_xpath_node(self._xmlstate.xml_ctx,
self.get_root_xpath())
def validate(self):
"""
Validate any set values and raise an exception if there's
a problem
"""
pass
def set_defaults(self, guest):
"""
Encode any default values if needed
"""
ignore = guest
###################
# Child overrides #
###################
def _prepare_get_xml(self):
"""
Subclasses can override this to do any pre-get_xml_config setup.
Returns data to pass to finish_get_xml
"""
return None
def _finish_get_xml(self, data):
"""
Called after get_xml_config. Data is whatever was returned by
_prepare_get_xml
"""
ignore = data
################
# Internal API #
################
def __get_prop_cache(self, cachename, checkclass):
if not hasattr(self.__class__, cachename):
ret = {}
for c in reversed(type.mro(self.__class__)[:-1]):
for key, val in c.__dict__.items():
if isinstance(val, checkclass):
ret[key] = val
setattr(self.__class__, cachename, ret)
return getattr(self.__class__, cachename)
def _all_xml_props(self):
"""
Return a list of all XMLProperty instances that this class has.
"""
cachename = self.__class__.__name__ + "_cached_xml_props"
return self.__get_prop_cache(cachename, XMLProperty)
def _all_child_props(self):
"""
Return a list of all XMLChildProperty instances that this class has.
"""
cachename = self.__class__.__name__ + "_cached_child_props"
return self.__get_prop_cache(cachename, XMLChildProperty)
def _set_parent_xpath(self, xpath):
self._xmlstate.set_parent_xpath(xpath)
for propname in self._all_child_props():
for p in util.listify(getattr(self, propname, [])):
p._set_parent_xpath(self.get_root_xpath())
def _set_relative_object_xpath(self, xpath):
self._xmlstate.set_relative_object_xpath(xpath)
for propname in self._all_child_props():
for p in util.listify(getattr(self, propname, [])):
p._set_parent_xpath(self.get_root_xpath())
def _find_child_prop(self, child_class):
xmlprops = self._all_child_props()
for xmlprop in xmlprops.values():
if xmlprop.is_single:
continue
if child_class in xmlprop.child_classes:
return xmlprop
raise RuntimeError("programming error: "
"Didn't find child property for child_class=%s" %
child_class)
def _parse_with_children(self, *args, **kwargs):
"""
Set new backing XML objects in ourselves and all our child props
"""
self._xmlstate._parse(*args, **kwargs)
for propname in self._all_child_props():
for p in util.listify(getattr(self, propname, [])):
p._xmlstate._parse(None, self._xmlstate.xml_node)
def _add_child(self, obj):
"""
Insert the passed XMLBuilder object into our XML document. The
object needs to have an associated mapping via XMLChildProperty
"""
xmlprop = self._find_child_prop(obj.__class__)
xml = obj.get_xml_config()
xmlprop.append(self, obj)
self._set_child_xpaths()
if not obj._xmlstate.is_build:
use_xpath = obj.get_root_xpath().rsplit("/", 1)[0]
indent = 2 * obj.get_root_xpath().count("/")
newnode = libxml2.parseDoc(util.xml_indent(xml, indent)).children
_build_xpath_node(self._xmlstate.xml_ctx, use_xpath, newnode)
obj._parse_with_children(None, self._xmlstate.xml_node)
def _remove_child(self, obj):
"""
Remove the passed XMLBuilder object from our XML document, but
ensure it's data isn't altered.
"""
xmlprop = self._find_child_prop(obj.__class__)
xmlprop.remove(self, obj)
xpath = obj.get_root_xpath()
xml = obj.get_xml_config()
obj._set_parent_xpath(None)
obj._set_relative_object_xpath(None)
obj._parse_with_children(xml, None)
_remove_xpath_node(self._xmlstate.xml_ctx, xpath, dofree=False)
self._set_child_xpaths()
#################################
# Private XML building routines #
#################################
def _set_child_xpaths(self):
"""
Walk the list of child properties and make sure their
xpaths point at their particular element
"""
typecount = {}
for propname, xmlprop in self._all_child_props().items():
for obj in util.listify(getattr(self, propname)):
idxstr = ""
if not xmlprop.is_single:
class_type = obj.__class__
if class_type not in typecount:
typecount[class_type] = 0
typecount[class_type] += 1
idxstr = "[%d]" % typecount[class_type]
prop_path = xmlprop.get_prop_xpath(self, obj)
obj._set_parent_xpath(self.get_root_xpath())
obj._set_relative_object_xpath(prop_path + idxstr)
def _do_get_xml_config(self):
xmlstub = self._xmlstate.make_xml_stub()
try:
node = None
ctx = self._xmlstate.xml_ctx
if self._xmlstate.is_build:
node = self._xmlstate.xml_node.docCopyNodeList(
self._xmlstate.xml_node.doc)
ctx = node
self._add_parse_bits(node)
ret = self._xmlstate.get_node_xml(ctx)
finally:
if node:
node.freeNode()
if ret == xmlstub:
ret = ""
# Ensure top level XML object always ends with a newline, just
# for back compat and readability
if (ret and not self.get_root_xpath() and not ret.endswith("\n")):
ret += "\n"
return ret
def _add_parse_bits(self, node):
"""
Callback that adds the implicitly tracked XML properties to
the backing xml.
"""
origproporder = self._proporder[:]
origpropstore = self._propstore.copy()
try:
return self._do_add_parse_bits(node)
finally:
self._proporder = origproporder
self._propstore = origpropstore
def _do_add_parse_bits(self, node):
# Set all defaults if the properties have one registered
xmlprops = self._all_xml_props()
childprops = self._all_child_props()
for prop in xmlprops.values():
prop._set_default(self)
# Set up preferred XML ordering
do_order = self._proporder[:]
for key in reversed(self._XML_PROP_ORDER):
if key not in xmlprops and key not in childprops:
raise RuntimeError("programming error: key '%s' must be "
"xml prop or child prop" % key)
if key in do_order:
do_order.remove(key)
do_order.insert(0, key)
elif key in childprops:
do_order.insert(0, key)
for key in childprops.keys():
if key not in do_order:
do_order.append(key)
# Alter the XML
for key in do_order:
if key in xmlprops:
xmlprops[key]._set_xml(self, self._propstore[key], node)
elif key in childprops:
for obj in util.listify(getattr(self, key)):
obj._add_parse_bits(node)