Am 13.07.2017 um 17:06 schrieb Daniel P. Berrange:
On Thu, Jul 13, 2017 at 05:02:51PM +0200, Peter Lieven wrote:
Am 13.07.2017 um 17:01 schrieb Daniel P. Berrange:
On Thu, Jul 13, 2017 at 05:00:39PM +0200, Peter Lieven wrote:
Am 13.07.2017 um 16:58 schrieb Daniel P. Berrange:
On Thu, Jul 13, 2017 at 04:18:13PM +0200, Peter Lieven wrote:
Okay, so it has to be a mix of QAPI parsing and manual parameter checking,
right?
Yeah. It does feel like a valid RFE for QAPI to add a permitted range to
'int' types though, which would simplify the code in future.
I currently have the following:
options = qemu_opts_to_qdict(opts, NULL);
qdict_extract_subqdict(options, &compressopts, "compress.");
v = qobject_input_visitor_new_keyval(QOBJECT(compressopts));
visit_start_struct(v, NULL, NULL, 0, &local_err);
if (local_err) {
ret= -EINVAL;
goto finish;
}
visit_type_Qcow2Compress_members(v, &compress, &local_err);
if (local_err) {
ret= -EINVAL;
goto finish;
}
visit_end_struct(v, NULL);
visit_free(v);
QDECREF(compressopts);
QDECREF(options)
Looks good.
And I have the following 2 questions:
a) I have to specifiy compress.format and compress.level otherwise I will
get an error. How can I fix that the settings are optional?
Put an '*' as the first character of any field name if it should be optional.
b) If I just specify a compress.format can I default the compress.level to
0 without an error?
I believe you'd get compress.level as 0 automatically for an 'int' type.
I still face the issue that I now always have to specify a compress.format.
I tried to solve it like this:
[snip]
that's not needed if you name the parameter '*level' in the QAPI schema
its not needed for the *level, but I still get the error that the format
parameter is missing otherwise. And I can't make format optional.
Surely specifying compress.format is how you turn on compression in the
first place, so making that optional should not be necessary. eg the
simple case becomes:
qemu-img create -f qcow2 -o compress.format=zlib foo.qcow2 1G
Yes, there is no notion of a "default" format, but IMHO that's a good
thing - same way with encryption - it requires an explict encrypt.format=luks
to turn on encryption
Yes, but visit_type_Qcow2Compress_members always returns an error if
compress.format
is missing from the options. So I should not call it an error out if
compress.format is not in the
options. Thus the check if either compress.format or compress.level is
specified at all.
Peter
