storage: Use XMLBuilder for pool enumerate parsing

And kill the parse_node_helper function, since that paradigm is dead.

virtinst/storage.py

@@ -165,30 +165,33 @@ class StoragePool(_StorageObject):
                 return []
             raise
 
-        def source_parser(node):
-            ret = []
+        class _EnumerateSource(XMLBuilder):
+            _XML_ROOT_NAME = "source"
+        class _EnumerateSources(XMLBuilder):
+            _XML_ROOT_NAME = "sources"
+            sources = XMLChildProperty(_EnumerateSource)
 
-            child = node.children
-            while child:
-                if child.name == "source":
-                    xml = "<pool>\n%s\n</pool>" % (
-                        util.xml_indent(child.serialize(format=1), 2))
-                    parseobj = StoragePool(conn, parsexml=xml)
-                    parseobj.type = pool_type
 
-                    obj = StoragePool(conn)
-                    obj.type = pool_type
-                    obj.source_path = parseobj.source_path
-                    for host in parseobj.hosts:
-                        parseobj.remove_host(host)
-                        obj.add_host_obj(host)
-                    obj.source_name = parseobj.source_name
-                    obj.format = parseobj.format
-                    ret.append(obj)
-                child = child.next
-            return ret
+        ret = []
+        sources = _EnumerateSources(conn, xml)
+        for source in sources.sources:
+            source_xml = source.get_xml_config()
 
-        return util.parse_node_helper(xml, "sources", source_parser)
+            pool_xml = "<pool>\n%s\n</pool>" % (util.xml_indent(source_xml, 2))
+            parseobj = StoragePool(conn, parsexml=pool_xml)
+            parseobj.type = pool_type
+
+            obj = StoragePool(conn)
+            obj.type = pool_type
+            obj.source_path = parseobj.source_path
+            for host in parseobj.hosts:
+                parseobj.remove_host(host)
+                obj.add_host_obj(host)
+            obj.source_name = parseobj.source_name
+            obj.format = parseobj.format
+
+            ret.append(obj)
+        return ret
 
     @staticmethod
     def build_default_pool(conn):

virtinst/util.py

@@ -25,7 +25,6 @@ import re
 import stat
 
 import libvirt
-import libxml2
 
 
 _host_blktap_capable = None
@@ -248,42 +247,6 @@ def default_bridge(conn):
     return None
 
 
-def parse_node_helper(xml, root_name, callback, exec_class=ValueError):
-    """
-    Parse the passed XML, expecting root as root_name, and pass the
-    root node to callback
-    """
-    class ErrorHandler(object):
-        def __init__(self):
-            self.msg = ""
-        def handler(self, ignore, s):
-            self.msg += s
-    error = ErrorHandler()
-    libxml2.registerErrorHandler(error.handler, None)
-
-    try:
-        try:
-            doc = libxml2.readMemory(xml, len(xml),
-                                     None, None,
-                                     libxml2.XML_PARSE_NOBLANKS)
-        except (libxml2.parserError, libxml2.treeError), e:
-            raise exec_class("%s\n%s" % (e, error.msg))
-    finally:
-        libxml2.registerErrorHandler(None, None)
-
-    ret = None
-    try:
-        root = doc.getRootElement()
-        if root.name != root_name:
-            raise ValueError("Root element is not '%s'" % root_name)
-
-        ret = callback(root)
-    finally:
-        doc.freeDoc()
-
-    return ret
-
-
 def generate_uuid(conn):
     for ignore in range(256):
         uuid = randomUUID(conn)