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

[Anthony Liguori]

On 06/15/2011 02:33 PM, Luiz Capitulino wrote:
> On Mon, 13 Jun 2011 21:31:14 -0500
> Michael Roth<address@hidden>  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);
> > +}