Data Logger: CSV Sink¶

Requirements ¶

A CSV implementation of the SinkLogger interface

Configurable columns: mapping sensor names (from SensorValues onto column names). Like so,

sink = CSVSink(
           "/path/to/logfile.csv",
           {
              { "LinksOben", "links-oben" },
              { "RechtsUnten", "rechts-unten" },
           });

SensorValues values;
values.addMeasurement("links-oben", 37.5);
values.addMeasurement("rechts-unten", 42.666);

sink.output(values);

This results in a CSV format similar to the following:

LinksOben;RechtsUnten
37.5;42.666

Implementation ¶

Column name configuration ¶

class CSVSink takes a std::vector<std::pair<std::string, std::string>> as column configuration. It remembers that object internally, as it will be used on every call to output().

`output()`¶

To bring the SensorValues into a CSV line, you iterate over the config, and lookup each entry in the SensorValues,

for (auto [csvname, valuename]: _config) {
     double value = sensor_values.getMeasurement(valuename);
     ... write value into "csvname" column ...
}

Testing ¶

Basic (ok) case
Error: bad config: referred name not found in SensorValues
Whatever error cases might come to mind

Future (Not Part Of This Development Cycle)¶

Log rotation. Users might want to backup what was logged, remove old data, and start a new file. The class must somehow support this.

Dependencies ¶