Convert nvidiamon enc/dec metrics from int to string

[amete]

This probably depends on a combination of the hardware/software/firmware but it looks like an output from nvidia-smi pmon [...] of the form:

# gpu        pid  type    sm   mem   enc   dec   command
# Idx          #   C/G     %     %     %     %   name
    0      14294     C    34     0     -     -   177   burner

is just as valid as:

# gpu        pid  type    sm   mem   enc   dec   command
# Idx          #   C/G     %     %     %     %   name
    0      14294     C    34     0     0     0   177   burner

Presumably not all metrics, especially enc and dec, are always available.

The main problem this creates is that the current implementation of the output parsing doesn't handle the first case well, resulting in all zero values for the gpu related metrics. In any case, we currently don't really track enc and dec explicitly. Therefore, I converted their types from unsigned int to std::string so that the parsing succeeds.

This should fix the problem that we've encountered in ADC (gpu related metrics being all zeros).

-s

[graeme-a-stewart]

Great - so glad you caught this! It's always a worry when parsing text output that needs to conform to a very specific format.

[amete]

Thanks a lot @graeme-a-stewart.