PPS synchronization status object

The PPS synchronization status object (by default, /pps/services/mm-detect/status) contains the latest synchronization statuses of all devices currently attached to the car infotainment system.

As the synchronization of newly attached devices progresses, the mm-detect service updates this PPS object while client applications monitor it to learn when media metadata has been synchronized.

The first line of this PPS object is of the form: [n]@status.

Following this first line, the synchronization statuses of individual devices are specified, one per line, in JSON format. The fields in the synchronization statuses include but aren't limited to:

the device's unique ID (UID)
the filesystem type (dos, qnx4, etc.)
the media type (ipod, usb, etc.)
the path of the storage file for the QDB database
a synchronization completion flag, stored as a Boolean attribute named synched

The full contents of this PPS object look like this:

[n]@status
db4f587192d2fe4efb9feccd35531cfa45:json:{"dbpath":"/dev/qdb/4f587192
d2fe4efb9feccd35531cfa45","mount":"/fs/usb0","name":"UNTITLED","fs_t
ype":"dos (fat32)","device_type":"usb","image_path":"/apps/mediasour
ces/imagecache/db4f587192d2fe4efb9feccd35531cfa45","synched":true}
dbmme:json:{"dbpath":"/dev/qdb/mme","mount":"/accounts/1000/shared/"
,"name":"Juke Box","fs_type":"qnx","device_type":"hdd","image_path":
"/apps/mediasources/imagecache/dbmme","synched":true}

A client application can read the synched field to determine whether all media information for a device is up to date, and then refresh the HMI display as appropriate. For example, when synched is false, the application could show an entry for the new device in a list of attached devices, but withhold the filesystem view of that device. When synched is true, the application can display the information for all media files on the device, because that device's database contents are known to be up to date.