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

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

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.bouvier@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