Re: [Qemu-devel] [PATCH v6 04/22] qapi: extend qdict_flatten() for QLists

[Max Reitz <mreitz@redhat.com>]

On 20.12.2013 18:19, Max Reitz wrote:
> On 20.12.2013 10:46, Stefan Hajnoczi wrote:
>> On Thu, Dec 19, 2013 at 08:47:05PM +0100, Max Reitz wrote:
>>> Reversing qdict_array_split(), qdict_flatten() should flatten QLists as
>>> well by interpreting them as QDicts where every entry's key is its
>>> index.
>>>
>>> This allows bringing QDicts with QLists from QMP commands to the same
>>> form as they would be given as command-line options, thereby allowing
>>> them to be parsed the same way.
>>>
>>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>>> ---
>>>   qobject/qdict.c | 57 
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++------
>>>   1 file changed, 51 insertions(+), 6 deletions(-)
>> Please add a tests/check-qdict.c test case.
>>
>>> diff --git a/qobject/qdict.c b/qobject/qdict.c
>>> index fca1902..7b6b08a 100644
>>> --- a/qobject/qdict.c
>>> +++ b/qobject/qdict.c
>>> @@ -477,7 +477,46 @@ static void qdict_destroy_obj(QObject *obj)
>>>       g_free(qdict);
>>>   }
>>>   -static void qdict_do_flatten(QDict *qdict, QDict *target, const 
>>> char *prefix)
>>> +static void qdict_flatten_qdict(QDict *qdict, QDict *target,
>>> +                                const char *prefix);
>>> +
>>> +static void qdict_flatten_qlist(QList *qlist, QDict *target, const 
>>> char *prefix)
>>> +{
>>> +    QObject *value;
>>> +    const QListEntry *entry;
>>> +    char *new_key;
>>> +    int i;
>>> +
>>> +    /* This function is never called with prefix == NULL, i.e., it 
>>> is always
>>> +     * called from within qdict_flatten_q(list|dict)(). Therefore, 
>>> it does not
>>> +     * need to remove list entries during the iteration (the whole 
>>> list will be
>>> +     * deleted eventually anyway from qdict_flatten_qdict()). */
>>> +    assert(prefix);
>>> +
>>> +    entry = qlist_first(qlist);
>>> +
>>> +    for (i = 0; entry; entry = qlist_next(entry), i++) {
>>> +        value = qlist_entry_obj(entry);
>>> +
>>> +        qobject_incref(value);
>>> +        new_key = g_strdup_printf("%s.%i", prefix, i);
>>> +        qdict_put_obj(target, new_key, value);
>> It seems this operation is clobbered by what follows and should be
>> deleted.  Is the incref also superfluous or...
>>
>>> +
>>> +        if (qobject_type(value) == QTYPE_QDICT) {
>>> +            qdict_flatten_qdict(qobject_to_qdict(value), target, 
>>> new_key);
>>> +        } else if (qobject_type(value) == QTYPE_QLIST) {
>>> +            qdict_flatten_qlist(qobject_to_qlist(value), target, 
>>> new_key);
>>> +        } else {
>>> +            /* All other types are moved to the target unchanged. */
>>> +            qobject_incref(value);
>> ...should this one be deleted?
>
> Oh great, I've been fixing working code, then. *g*
>
> I added the else branch in v5, I guess, it was correct not to have it 
> (however, the condition in the else if was missing in v4). I'll drop 
> it again, thanks.

On second thought, that would be even more wrong. I'll leave the else 
branch and drop the qobject_incref() and qdict_put_obj() above the 
condition.

Max

>
>>> +            qdict_put_obj(target, new_key, value);
>>> +        }
>>> +
>>> +        g_free(new_key);
>>> +    }
>