qmi-codegen in libqmi-glib

[Aleksander Morgado]

Hey hey,

I've been playing a bit more with the idea of automatically generating
code for message handling from input JSON files, and got already
something working in the 'qmi-codegen' branch of my libqmi-glib tree:
  git://gitorious.org/lanedo/libqmi-glib.git

The current set of supported messages are defined in the following JSON
files:

https://gitorious.org/lanedo/libqmi-glib/blobs/qmi-codegen/data/qmi-common.json

https://gitorious.org/lanedo/libqmi-glib/blobs/qmi-codegen/data/qmi-service-ctl.json

https://gitorious.org/lanedo/libqmi-glib/blobs/qmi-codegen/data/qmi-service-dms.json

https://gitorious.org/lanedo/libqmi-glib/blobs/qmi-codegen/data/qmi-service-wds.json

And adding new messages should need, ideally, just updating these JSON
files. I guess the qmi-codegen will need updates from time to time when
new basic types are found in the QMI messages. Currently the following
types are supported:
 * integers (uint8/uint16/uint32/int8/int16/int32)
 * strings
 * structs with integer contents
 * arrays of structs


The new qmi-codegen python program will read the per-service input JSON
files, and for each request/response, we will define GIO Async methods,
like:

void qmi_client_ctl_allocate_cid (
    QmiClientCtl *self,
    QmiMessageCtlAllocateCidInput *input,
    guint timeout,
    GCancellable *cancellable,
    GAsyncReadyCallback callback,
    gpointer user_data);
QmiMessageCtlAllocateCidOutput *qmi_client_ctl_allocate_cid_finish (
    QmiClientCtl *self,
    GAsyncResult *res,
    GError **error);

We then provide methods to create/ref/unref the
QmiMessageCtlAllocateCidInput bundle, as well as methods to get/set
specific TLVs, like:

gboolean qmi_message_ctl_allocate_cid_input_get_service (
    QmiMessageCtlAllocateCidInput *self,
    QmiService *value,
    GError **error);
gboolean qmi_message_ctl_allocate_cid_input_set_service (
    QmiMessageCtlAllocateCidInput *self,
    QmiService value,
    GError **error);
QmiMessageCtlAllocateCidInput *qmi_message_ctl_allocate_cid_input_ref
    (QmiMessageCtlAllocateCidInput *self);
void qmi_message_ctl_allocate_cid_input_unref
    (QmiMessageCtlAllocateCidInput *self);
QmiMessageCtlAllocateCidInput *qmi_message_ctl_allocate_cid_input_new
    (void);

And the same for output bundles like the QmiMessageCtlAllocateCidOutput:

typedef struct _QmiMessageCtlAllocateCidOutputAllocationInfo {
    QmiService service;
    guint8 cid;
} QmiMessageCtlAllocateCidOutputAllocationInfo;

gboolean qmi_message_ctl_allocate_cid_output_get_result (
    QmiMessageCtlAllocateCidOutput *self,
    GError **error);
gboolean qmi_message_ctl_allocate_cid_output_get_allocation_info (
    QmiMessageCtlAllocateCidOutput *self,
    QmiMessageCtlAllocateCidOutputAllocationInfo *value,
    GError **error);
QmiMessageCtlAllocateCidOutput *qmi_message_ctl_allocate_cid_output_ref
    (QmiMessageCtlAllocateCidOutput *self);
void qmi_message_ctl_allocate_cid_output_unref
    (QmiMessageCtlAllocateCidOutput *self);


In order to keep API/ABI compatibility whenever the QMI protocol is
updated, all input TLVs and output TLVs are packed into the input and
output 'bundles'. Here I'm assuming that QMI protocol updates are either
new messages or full new TLVs in already existing messages; or in other
words, assuming that existing TLVs are not supposed to get modified
(which is why for struct TLVs we define the struct itself in the public
interface).

When compiling with -DMESSAGE_ENABLE_TRACE, it enables tracing of the
ongoing messages, which now also includes properly printing the TLV
values (when known), like:

<<<<<< QMUX:
<<<<<<   length  = 16
<<<<<<   flags   = 0x00
<<<<<<   service = "ctl"
<<<<<<   client  = 0
<<<<<< QMI:
<<<<<<   flags       = "none"
<<<<<<   transaction = 3
<<<<<<   tlv_length  = 5
<<<<<<   message     = "Release CID" (0x0023)
<<<<<< TLV:
<<<<<<   type       = "Release Info" (0x01)
<<<<<<   length     = 2
<<<<<<   value      = 02:13
<<<<<<   translated =
<<<<<<      [Service = 2]
<<<<<<      [Cid = 19]


Tests with this branch are highly appreciated, as I would like to merge
it to libqmi-glib master sooner than later.

Cheers!

-- 
Aleksander