Re: [libvirt] [PATCH v2 2/4] virnetdev: Introduce virNetDevGetLinkInfo
On 11.06.2014 11:19, Michal Privoznik wrote:
> <snip/>
> Seems we should be able to set up a dummy /sys/class/net environment in
> order to test the new API's... Something I attempted with my recently
> posted scsi_host changes.
Yeah, unit testing is certainly in place. But honestly, I thought it
would blow the size of this patches up. Again, something that a follow
up patch will do.
So, now that I'm thinking about how to implement this I see two possible
ways which I'm unable to choose between:
1) mock higher level functions like virNetDevSysfsFile() or
virNetDevSetupControl(). So if a function wants to reach say
"/sys/class/net/eth0/operstate" we can direct it into
"tests/virnetdevdata/class/net/eth0/operstate"
Pros:
- small set of high level functions, so the code should be rather small.
- we can keep whole sysfs dir struct in git
Cons:
- Unable to simulate some corner cases (e.g. EINVAL on read()).
- keeping whole sysfs dir struct in git
2) mock lowlevel functions, like open(), ioctl(), etc. There's plenty of
functions in virnetdev.c that use lowlevel functions like socket(),
ioctl() to get data.
Pros:
- we can model kernel behavior more closely (e.g. even run time setting
of some values like MAC/IP addressese, link state, you name it)
- clean git
Cons:
- much more code
I'm not hesitant to write the code, but I'd rather have an agreement on
the design before that.
Michal