reusable rate func for flux

rate.flux

v1Measurement = (tables=<-, measurement) =>
    tables
        |> filter(fn: (r) => r._measurement == measurement)



v1Fields = (tables=<-, fields=[]) =>
  if length(arr: fields) == 0 then
    tables
  else
    tables
      |> filter(fn: (r) => contains(value: r._field, set: fields))



v1Select = (bucket, start=v.timeRangeStart, stop=v.timeRangeStop) =>
    from(bucket: bucket)
        |> range(start, stop)



inBucket = (bucket, start=v.timeRangeStart, stop=v.timeRangeStop, measurement, fields=[], predicate=(r) => true) =>
  v1Select(bucket, start, stop)
    |> v1Measurement(measurement)
    |> filter(fn: predicate)
    |> v1Fields(fields)




rateDet = (table=<-, unit=0s, nonNegative=true) =>
    if string(v: unit) == "0s" then
        table
          |> difference(nonNegative: nonNegative, columns: ["_value"])
    else
        table
          |> derivative(unit: unit, nonNegative: nonNegative, columns: ["_value"], timeColumn: "_time")



rate = (
  bucket,
  start=v.timeRangeStart,
  stop=v.timeRangeStop,
  measurement,
  unit=0s,
  nonNegative=true,
  fields=[],
  predicate=(r) => true
) =>
  inBucket(bucket, start, stop, measurement, fields, predicate)
    |> 
    |> rateDet(unit: unit, nonNegative: nonNegative)