qom: Introduce ObjectPropertyIterator struct for iteration

Some users of QOM need to be able to iterate over properties
defined against an object instance. Currently they are just
directly using the QTAIL macros against the object properties
data structure.

This is bad because it exposes them to changes in the data
structure used to store properties, as well as changes in
functionality such as ability to register properties against
the class.

This provides an ObjectPropertyIterator struct which will
insulate the callers from the particular data structure
used to store properties. It can be used thus

  ObjectProperty *prop;
  ObjectPropertyIterator *iter;

  iter = object_property_iter_init(obj);
  while ((prop = object_property_iter_next(iter))) {
      ... do something with prop ...
  }
  object_property_iter_free(iter);

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Tested-by: Pavel Fedin <p.fedin@samsung.com>
[AF: Fixed examples, style cleanups]
Signed-off-by: Andreas Färber <afaerber@suse.de>

1 files changed, 46 insertions, 0 deletions

diff --git a/tests/check-qom-proplist.c b/tests/check-qom-proplist.c
index 7400b1fce9..1be8b9e6f2 100644
--- a/tests/check-qom-proplist.c
+++ b/tests/check-qom-proplist.c
@@ -283,6 +283,51 @@ static void test_dummy_getenum(void)
                                    &err);
     g_assert(err != NULL);
     error_free(err);
+
+    object_unparent(OBJECT(dobj));
+}
+
+
+static void test_dummy_iterator(void)
+{
+    Object *parent = object_get_objects_root();
+    DummyObject *dobj = DUMMY_OBJECT(
+        object_new_with_props(TYPE_DUMMY,
+                              parent,
+                              "dummy0",
+                              &error_abort,
+                              "bv", "yes",
+                              "sv", "Hiss hiss hiss",
+                              "av", "platypus",
+                              NULL));
+
+    ObjectProperty *prop;
+    ObjectPropertyIterator *iter;
+    bool seenbv = false, seensv = false, seenav = false, seentype;
+
+    iter = object_property_iter_init(OBJECT(dobj));
+    while ((prop = object_property_iter_next(iter))) {
+        if (g_str_equal(prop->name, "bv")) {
+            seenbv = true;
+        } else if (g_str_equal(prop->name, "sv")) {
+            seensv = true;
+        } else if (g_str_equal(prop->name, "av")) {
+            seenav = true;
+        } else if (g_str_equal(prop->name, "type")) {
+            /* This prop comes from the base Object class */
+            seentype = true;
+        } else {
+            g_printerr("Found prop '%s'\n", prop->name);
+            g_assert_not_reached();
+        }
+    }
+    object_property_iter_free(iter);
+    g_assert(seenbv);
+    g_assert(seenav);
+    g_assert(seensv);
+    g_assert(seentype);
+
+    object_unparent(OBJECT(dobj));
 }
 
 
@@ -297,6 +342,7 @@ int main(int argc, char **argv)
     g_test_add_func("/qom/proplist/createv", test_dummy_createv);
     g_test_add_func("/qom/proplist/badenum", test_dummy_badenum);
     g_test_add_func("/qom/proplist/getenum", test_dummy_getenum);
+    g_test_add_func("/qom/proplist/iterator", test_dummy_iterator);
 
     return g_test_run();
 }