[PATCH V4 2/3] python: use qom-list-get

[Steve Sistare <steven.sistare@oracle.com>]

Use qom-list-get to speed up the qom-tree command.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 python/qemu/utils/qom.py        | 43 +++++++++++++++++++--------------
 python/qemu/utils/qom_common.py | 53 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 18 deletions(-)

diff --git a/python/qemu/utils/qom.py b/python/qemu/utils/qom.py
index 426a0f2..337ae29 100644
--- a/python/qemu/utils/qom.py
+++ b/python/qemu/utils/qom.py
@@ -224,28 +224,35 @@ def __init__(self, args: argparse.Namespace):
         super().__init__(args)
         self.path = args.path
 
-    def _list_node(self, path: str) -> None:
-        print(path)
-        items = self.qom_list(path)
-        for item in items:
-            if item.child:
-                continue
-            try:
-                rsp = self.qmp.cmd('qom-get', path=path,
-                                   property=item.name)
-                print(f"  {item.name}: {rsp} ({item.type})")
-            except ExecuteError as err:
-                print(f"  {item.name}: <EXCEPTION: {err!s}> ({item.type})")
-        print('')
-        for item in items:
-            if not item.child:
-                continue
+    def _list_nodes(self, paths: [str]) -> None:
+        all_paths_props = self.qom_list_get(paths)
+        i = 0
+
+        for props in all_paths_props:
+            path = paths[i]
+            i = i + 1
+            print(path)
             if path == '/':
                 path = ''
-            self._list_node(f"{path}/{item.name}")
+            newpaths = []
+
+            for item in props.properties:
+                if item.child:
+                    newpaths += [ f"{path}/{item.name}" ]
+                else:
+                    value = item.value
+                    if value == None:
+                        value = f"<EXCEPTION: property could not be read>"
+                    print(f"  {item.name}: {value} ({item.type})")
+
+            print('')
+
+            if newpaths:
+                self._list_nodes(newpaths)
+
 
     def run(self) -> int:
-        self._list_node(self.path)
+        self._list_nodes([self.path])
         return 0
 
 
diff --git a/python/qemu/utils/qom_common.py b/python/qemu/utils/qom_common.py
index dd2c8b1..e471f1d 100644
--- a/python/qemu/utils/qom_common.py
+++ b/python/qemu/utils/qom_common.py
@@ -65,6 +65,50 @@ def link(self) -> bool:
         return self.type.startswith('link<')
 
 
+class ObjectPropertyValue:
+    """
+    Represents a property return from e.g. qom-tree-get
+    """
+    def __init__(self, name: str, type_: str, value: object):
+        self.name = name
+        self.type = type_
+        self.value = value
+
+    @classmethod
+    def make(cls, value: Dict[str, Any]) -> 'ObjectPropertyValue':
+        """
+        Build an ObjectPropertyValue from a Dict with an unknown shape.
+        """
+        assert value.keys() >= {'name', 'type'}
+        assert value.keys() <= {'name', 'type', 'value'}
+        return cls(value['name'], value['type'], value.get('value'))
+
+    @property
+    def child(self) -> bool:
+        """Is this property a child property?"""
+        return self.type.startswith('child<')
+
+
+class ObjectPropertiesValues:
+    """
+    Represents the return type from e.g. qom-list-get
+    """
+    def __init__(self, properties):
+        self.properties = properties
+
+    @classmethod
+    def make(cls, value: Dict[str, Any]) -> 'ObjectPropertiesValues':
+        """
+        Build an ObjectPropertiesValues from a Dict with an unknown shape.
+        """
+        assert value.keys() == {'properties'}
+        props = [ObjectPropertyValue(item['name'],
+                                     item['type'],
+                                     item.get('value'))
+                 for item in value['properties']]
+        return cls(props)
+
+
 CommandT = TypeVar('CommandT', bound='QOMCommand')
 
 
@@ -145,6 +189,15 @@ def qom_list(self, path: str) -> List[ObjectPropertyInfo]:
         assert isinstance(rsp, list)
         return [ObjectPropertyInfo.make(x) for x in rsp]
 
+    def qom_list_get(self, paths) -> List[ObjectPropertiesValues]:
+        """
+        :return: a strongly typed list from the 'qom-list-get' command.
+        """
+        rsp = self.qmp.cmd('qom-list-get', paths=paths)
+        # qom-list-get returns List[ObjectPropertiesValues]
+        assert isinstance(rsp, list)
+        return [ObjectPropertiesValues.make(x) for x in rsp]
+
     @classmethod
     def command_runner(
             cls: Type[CommandT],
-- 
1.8.3.1