Re: [Qemu-devel] [PATCH v3 09/21] qapi: add QMP dispatch functions

[Anthony Liguori <aliguori@us.ibm.com>]

On 06/15/2011 02:33 PM, Luiz Capitulino wrote:
> On Mon, 13 Jun 2011 21:31:14 -0500
> Michael Roth<mdroth@linux.vnet.ibm.com>  wrote:
>
>
>> +{
>> +    const char *command;
>> +    QDict *args, *dict;
>> +    QmpCommand *cmd;
>> +    QObject *ret = NULL;
>> +
>> +    if (qobject_type(request) != QTYPE_QDICT) {
>> +        error_set(errp, QERR_JSON_PARSE_ERROR, "request is not a dictionary");
>> +        goto out;
>> +    }
>> +
>> +    dict = qobject_to_qdict(request);
>> +    if (!qdict_haskey(dict, "execute")) {
>> +        error_set(errp, QERR_JSON_PARSE_ERROR, "no execute key");
>> +        goto out;
>> +    }
>> +
>> +    command = qdict_get_str(dict, "execute");
>> +    cmd = qmp_find_command(command);
>> +    if (cmd == NULL) {
>> +        error_set(errp, QERR_COMMAND_NOT_FOUND, command);
>> +        goto out;
>> +    }
>> +
>> +    if (!qdict_haskey(dict, "arguments")) {
>> +        args = qdict_new();
>> +    } else {
>> +        args = qdict_get_qdict(dict, "arguments");
>> +        QINCREF(args);
>> +    }
>
> This function doesn't seem to handle extra keys in the command dict, like:
>
>   { "execute": "query-block", "foo": "bar" }
>
> You probably want to use qmp_check_input_obj() here.

That's a feature, no?

"Be liberal in what you accept, conservative in what you send."

>
>> +
>> +    switch (cmd->type) {
>> +    case QCT_NORMAL:
>> +        cmd->fn(args,&ret, errp);
>> +        if (!error_is_set(errp)&&  ret == NULL) {
>> +            ret = QOBJECT(qdict_new());
>> +        }
>> +        break;
>> +    }
>> +
>> +    QDECREF(args);
>> +
>> +out:
>> +
>> +    return ret;
>> +}
>> +
>> +QObject *qmp_dispatch(QObject *request)
>> +{
>> +    Error *err = NULL;
>> +    QObject *ret;
>> +    QDict *rsp;
>> +
>> +    ret = qmp_dispatch_err(request,&err);
>> +
>> +    rsp = qdict_new();
>> +    if (err) {
>> +        qdict_put_obj(rsp, "error", error_get_qobject(err));
>> +        error_free(err);
>> +    } else if (ret) {
>> +        qdict_put_obj(rsp, "return", ret);
>> +    } else {
>> +        QDECREF(rsp);
>> +        return NULL;
>
> When does the 'else' condition happens?

Signals which aren't in this patch series.

Regards,

Anthony Liguori

>
>> +    }
>> +
>> +    return QOBJECT(rsp);
>> +}
>