We may want to be able to talk with the device while it's closed to
queue commands to be performed once it opens (could be even a script),
so to do this we need to close the device first, send those commands and
eventually process them.
We used a trick to send an invalid command before that was ignored by
release, but having the device available is just easier to handle.
So, when keep alive is enabled we don't stop the listener when closing
but only on actual device disposition.
When opening the device we can process commands that we left for that
after the previous close, to do that we only have to inject an invalid
command that will be processed (and ignored) while closing, so that at
next device opening we will be able to proceed with the previously
sent commands.
Add tests to finally check this case!
Each command should be separated by SLEEP to be considered as something
we want to perform during the current operation, otherwise will be used
by next operation consuming it.
In case we sent a sleep event to the device we may want to wait it to
emit the finger needed state before the timeout is completed.
So add a function to manage this for all the scan cases
There are two variants one with storage and identify support and the
other without storage.
It implements the following commands:
* INSERT id
* REMOVE id
* SCAN id
* ERROR error-code
* LIST (returns saved print)
The INSERT/REMOVE/LIST commands are only available in the storage
driver. The SCAN command emulates presenting a finger.
These commands can be send ahead of time, and will be queued and
processed when appropriate. i.e. for INSERT/REMOVE that is immediately
when possible, for SCAN/ERROR processing is delayed.
The LIST command is always processed immediately.
Note that only a single command can be send per socket connection and
the command must be send in a single message. The socket will be closed
after the command has been processed.
Co-authored-by: Bastien Nocera <hadess@hadess.net>
Co-authored-by: Marco Trevisan (Treviño) <mail@3v1n0.net>