Re: [PATCH 03/13] qobject/qlit: allow to hide dict or list entries

[Pierrick Bouvier]

On 5/8/25 7:21 AM, Daniel P. Berrangé wrote:
On Wed, May 07, 2025 at 04:14:33PM -0700, Pierrick Bouvier wrote:
We add a new .hidden field to qlit entries, which gets ignored when
creating the associated QObject.
By default .hidden is 0, so it means the entry is visible. This way,
only potentially hidden elements need to be assigned.

IMHO this feels like a somewhat dubious concept to have in the
qobject code, as it is quite specialized to a single use case.
A more general purpose approach would be to have some mechanism
for cloning while applying a data filter, though I admit that
may be more tedious to actually use.


It's the least worse solution I found, for conditionally defining the 
schema.
Trying to dynamically create the qlit stuff with individual .push() was 
a nightmare in code generator, so I dropped this idea.


Signed-off-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
---
  include/qobject/qlit.h | 12 ++++++++++++
  qobject/qlit.c         | 10 ++++++++--
  2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/include/qobject/qlit.h b/include/qobject/qlit.h
index c0676d5daf2..3b66c22013c 100644
--- a/include/qobject/qlit.h
+++ b/include/qobject/qlit.h
@@ -28,25 +28,37 @@ struct QLitObject {
          QLitDictEntry *qdict;
          QLitObject *qlist;
      } value;
+    bool hidden;
  };
  
  struct QLitDictEntry {
      const char *key;
      QLitObject value;
+    bool hidden;
  };
  
  #define QLIT_QNULL \
      { .type = QTYPE_QNULL }
  #define QLIT_QBOOL(val) \
      { .type = QTYPE_QBOOL, .value.qbool = (val) }
+#define QLIT_QBOOL_HIDDEN(val, cond) \
+    { .type = QTYPE_QBOOL, .value.qbool = (val), .hidden = (cond) }
  #define QLIT_QNUM(val) \
      { .type = QTYPE_QNUM, .value.qnum = (val) }
+#define QLIT_QNUM_HIDDEN(val, cond) \
+    { .type = QTYPE_QNUM, .value.qnum = (val), .hidden = (cond) }
  #define QLIT_QSTR(val) \
      { .type = QTYPE_QSTRING, .value.qstr = (val) }
+#define QLIT_QSTR_HIDDEN(val, cond) \
+    { .type = QTYPE_QSTRING, .value.qstr = (val), .hidden = (cond) }
  #define QLIT_QDICT(val) \
      { .type = QTYPE_QDICT, .value.qdict = (val) }
+#define QLIT_QDICT_HIDDEN(val, cond) \
+    { .type = QTYPE_QDICT, .value.qdict = (val), .hidden = (cond) }
  #define QLIT_QLIST(val) \
      { .type = QTYPE_QLIST, .value.qlist = (val) }
+#define QLIT_QLIST_HIDDEN(val, cond) \
+    { .type = QTYPE_QLIST, .value.qlist = (val), .hidden = (cond) }
  
  bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs);
  
diff --git a/qobject/qlit.c b/qobject/qlit.c
index a44f47eaa57..7b372c5ebaa 100644
--- a/qobject/qlit.c
+++ b/qobject/qlit.c
@@ -90,6 +90,8 @@ bool qlit_equal_qobject(const QLitObject *lhs, const QObject 
*rhs)
  
  QObject *qobject_from_qlit(const QLitObject *qlit)
  {
+    g_assert(!qlit->hidden);
+
      switch (qlit->type) {
      case QTYPE_QNULL:
          return QOBJECT(qnull());
@@ -102,7 +104,9 @@ QObject *qobject_from_qlit(const QLitObject *qlit)
          QLitDictEntry *e;
  
          for (e = qlit->value.qdict; e->key; e++) {
-            qdict_put_obj(qdict, e->key, qobject_from_qlit(&e->value));
+            if (!e->hidden) {
+                qdict_put_obj(qdict, e->key, qobject_from_qlit(&e->value));
+            }
          }
          return QOBJECT(qdict);
      }
@@ -111,7 +115,9 @@ QObject *qobject_from_qlit(const QLitObject *qlit)
          QLitObject *e;
  
          for (e = qlit->value.qlist; e->type != QTYPE_NONE; e++) {
-            qlist_append_obj(qlist, qobject_from_qlit(e));
+            if (!e->hidden) {
+                qlist_append_obj(qlist, qobject_from_qlit(e));
+            }
          }
          return QOBJECT(qlist);
      }
--
2.47.2


With regards,
Daniel