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<mdr...@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);
+}