virt-manager/virtinst/XMLBuilderDomain.py
Cole Robinson abbc828b70 VirtualGraphics: Don't lookup local keymap over and over
Triggered with virt-manager: new vm -> customize before install with a
non qemu. Guest.get_xml_config copies each device so it can set defaults
in a non persistent way. Unfortunately VirtualGraphics was copied before
a keymap lookup was ever done. End result was that we called
util.default_keymap over and over which is slow and floods the logs.
2013-04-13 16:18:03 -04:00

557 lines
16 KiB
Python

#
# Base class for all VM devices
#
# Copyright 2008 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 threading
import libvirt
import libxml2
from virtinst import CapabilitiesParser
from virtinst import uriutil
from virtinst import util
_xml_refs_lock = threading.Lock()
_xml_refs = {}
def _unref_doc(doc):
if not doc:
return
idx = None
try:
_xml_refs_lock.acquire()
for n in _xml_refs:
if n == doc:
idx = n
break
if not idx:
return
_xml_refs[idx] = _xml_refs[idx] - 1
if _xml_refs[idx] == 0:
idx.freeDoc()
finally:
_xml_refs_lock.release()
def _ref_doc(doc):
if not doc:
return
try:
_xml_refs_lock.acquire()
idx = doc
for n in _xml_refs:
if n == doc:
idx = n
break
refcount = _xml_refs.get(idx) or 0
_xml_refs[idx] = refcount + 1
finally:
_xml_refs_lock.release()
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, is_multi=False):
node = ctx.xpathEval(xpath)
if not is_multi:
return (node and node[0] or None)
return node
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("")
parentnode.addChild(sib)
# This is 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
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()
node.unlinkNode()
if dofree:
node.freeNode()
def _xml_property(fget=None, fset=None, fdel=None, doc=None,
xpath=None, get_converter=None, set_converter=None,
xml_get_xpath=None, xml_set_xpath=None,
xml_set_list=None, is_bool=False, is_multi=False,
default_converter=None):
"""
Set a XMLBuilder class property that represents a value in the
<domain> XML. For example
name = _xml_property(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 fget: typical getter function for the property
@param fset: typical setter function for the property
@param fdel: typical deleter function for the property
@param doc: option doc string for the property
@param xpath: xpath string which maps to the associated property
in a typical XML document
@param get_converter:
@param set_converter: optional function for converting the property
value from the virtinst API to the guest XML. For example,
the Guest.memory API is in MB, but the libvirt domain memory API
is in KB. So, if xpath is specified, on a 'get' operation we need
to convert the XML value with int(val) / 1024.
@param xml_get_xpath:
@param xml_set_xpath: Not all props map cleanly to a static xpath.
This allows passing functions which generate an xpath for getting
or setting.
@param xml_set_list: Return a list of xpaths to set for each value
in the val list
@param is_bool: Whether this is a boolean property in the XML
@param is_multi: Whether data is coming multiple or a single node
@param default_converter: If the virtinst value is "default", use
this function to get the actual XML value
"""
# pylint: disable=W0212
# Accessing _xml vals of self. This should be a class method, but
# we break it out to be more readable
def new_getter(self, *args, **kwargs):
val = None
getval = fget(self, *args, **kwargs)
if not self._xml_node:
return getval
if default_converter and getval == "default":
return getval
usexpath = xpath
if xml_get_xpath:
usexpath = xml_get_xpath(self)
if usexpath is None:
return getval
nodes = util.listify(_get_xpath_node(self._xml_ctx,
usexpath, is_multi))
if nodes:
ret = []
for node in nodes:
val = node.content
if get_converter:
val = get_converter(self, val)
elif is_bool:
val = True
if not is_multi:
return val
# If user is querying multiple nodes, return a list of results
ret.append(val)
return ret
elif is_bool:
return False
elif get_converter:
getval = get_converter(self, None)
return getval
def new_setter(self, val, *args, **kwargs):
# Do this regardless, for validation purposes
fset(self, val, *args, **kwargs)
if not self._xml_node:
return
# Convert from API value to XML value
val = fget(self)
if set_converter:
val = set_converter(self, val)
elif default_converter and val == "default":
val = default_converter(self)
nodexpath = xpath
if xml_set_xpath:
nodexpath = xml_set_xpath(self)
if nodexpath is None:
return
nodes = util.listify(_get_xpath_node(self._xml_ctx,
nodexpath, is_multi))
xpath_list = nodexpath
if xml_set_list:
xpath_list = xml_set_list(self)
node_map = _tuplify_lists(nodes, val, xpath_list)
for node, val, usexpath in node_map:
if node:
usexpath = node.nodePath()
if val not in [None, False]:
if not node:
node = _build_xpath_node(self._xml_node, usexpath)
if val is True:
# Boolean property, creating the node is enough
pass
else:
node.setContent(util.xml_escape(str(val)))
else:
_remove_xpath_node(self._xml_node, usexpath)
if fdel:
# Not tested
raise RuntimeError("XML deleter not yet supported.")
return property(fget=new_getter, fset=new_setter, doc=doc)
class XMLBuilderDomain(object):
"""
Base for all classes which build or parse domain XML
"""
_dumpxml_xpath = "."
def __init__(self, conn=None, parsexml=None, parsexmlnode=None,
caps=None):
"""
Initialize state
@param conn: libvirt connection to validate device against
@type conn: virConnect
@param parsexml: Optional XML string to parse
@type parsexml: C{str}
@param parsexmlnode: Option xpathNode to use
@param caps: Capabilities() instance
"""
self._conn = None
self._conn_uri = None
self.__remote = False
self.__caps = None
self._xml_node = None
self._xml_ctx = None
if conn:
self.set_conn(conn)
if caps:
if not isinstance(caps, CapabilitiesParser.Capabilities):
raise ValueError("caps must be a Capabilities instance")
self.__caps = caps
if parsexml or parsexmlnode:
self._parsexml(parsexml, parsexmlnode)
def __del__(self):
try:
if self._xml_node:
_unref_doc(self._xml_node.doc)
except:
pass
try:
if self._xml_ctx:
self._xml_ctx.xpathFreeContext()
except:
pass
def _cache(self):
"""
This is a hook for classes to cache any state that is expensive
to lookup before we copy the object as part of Guest.get_xml_config.
Saves us from possibly doing the lookup over and over
"""
pass
def copy(self):
# Otherwise we can double free XML info
if self._is_parse():
return self
self._cache()
return copy.copy(self)
def get_conn(self):
return self._conn
def set_conn(self, val):
if not isinstance(val, libvirt.virConnect):
raise ValueError(_("'conn' must be a virConnect instance."))
self._conn = val
self._conn_uri = self._conn.getURI()
self.__remote = uriutil.is_uri_remote(self._conn_uri, conn=self._conn)
conn = property(get_conn, set_conn)
def get_uri(self):
return self._conn_uri
def _get_caps(self):
if not self.__caps and self.conn:
self.__caps = CapabilitiesParser.parse(self.conn.getCapabilities())
return self.__caps
def is_remote(self):
return bool(self.__remote)
def is_qemu(self):
return uriutil.is_qemu(self.conn, self.get_uri())
def is_qemu_system(self):
return uriutil.is_qemu_system(self.conn, self.get_uri())
def is_session_uri(self):
return uriutil.is_session_uri(self.conn, self.get_uri())
def is_xen(self):
return uriutil.is_xen(self.conn, self.get_uri())
def _check_bool(self, val, name):
if val not in [True, False]:
raise ValueError(_("'%s' must be True or False" % name))
def _check_str(self, val, name):
if type(val) is not str:
raise ValueError(_("'%s' must be a string, not '%s'." %
(name, type(val))))
def _is_parse(self):
return bool(self._xml_node or self._xml_ctx)
def set_xml_node(self, node):
self._parsexml(None, node)
def get_xml_node_path(self):
if self._xml_node:
return self._xml_node.nodePath()
return None
def _add_child_node(self, parent_xpath, newnode):
ret = _build_xpath_node(self._xml_ctx, parent_xpath, newnode)
return ret
def _remove_child_xpath(self, xpath):
_remove_xpath_node(self._xml_ctx, xpath, dofree=False)
self._set_xml_context()
def _set_xml_context(self):
doc = self._xml_node.doc
ctx = doc.xpathNewContext()
ctx.setContextNode(self._xml_node)
if self._xml_ctx:
self._xml_ctx.xpathFreeContext()
self._xml_ctx = ctx
def _parsexml(self, xml, node):
if xml:
self._xml_node = libxml2.parseDoc(xml).children
else:
self._xml_node = node
_ref_doc(self._xml_node.doc)
self._set_xml_context()
def _get_xml_config(self):
"""
Internal XML building function. Must be overwritten by subclass
"""
raise NotImplementedError()
def get_xml_config(self, *args, **kwargs):
"""
Construct and return object xml
@return: object xml representation as a string
@rtype: str
"""
if self._xml_ctx:
node = _get_xpath_node(self._xml_ctx, self._dumpxml_xpath)
if not node:
return ""
return _sanitize_libxml_xml(node.serialize())
return self._get_xml_config(*args, **kwargs)
@staticmethod
def indent(xmlstr, level):
xml = ""
if not xmlstr:
return xml
for l in iter(xmlstr.splitlines()):
xml += " " * level + l + "\n"
return xml