// NewOperator creates a new binary operator function.
// the binary operators display a natural join semantic.
func NewOperator(op string, operator func(float64, float64) float64) function.MetricFunction {
return function.MetricFunction{
Name: op,
MinArguments: 2,
MaxArguments: 2,
Compute: func(context *function.EvaluationContext, args []function.Expression, groups function.Groups) (function.Value, error) {
evaluated, err := function.EvaluateMany(context, args)
if err != nil {
return nil, err
}
leftValue := evaluated[0]
rightValue := evaluated[1]
leftList, err := leftValue.ToSeriesList(context.Timerange)
if err != nil {
return nil, err
}
rightList, err := rightValue.ToSeriesList(context.Timerange)
if err != nil {
return nil, err
}
joined := join.Join([]api.SeriesList{leftList, rightList})
result := make([]api.Timeseries, len(joined.Rows))
for i, row := range joined.Rows {
left := row.Row[0]
right := row.Row[1]
array := make([]float64, len(left.Values))
for j := 0; j < len(left.Values); j++ {
array[j] = operator(left.Values[j], right.Values[j])
}
result[i] = api.Timeseries{Values: array, TagSet: row.TagSet}
}
query := fmt.Sprintf("(%s %s %s)", leftValue.GetName(), op, rightValue.GetName())
return api.SeriesList{
Series: result,
Timerange: context.Timerange,
Name: query,
Query: query,
}, nil
},
}
}
// NewOperator creates a new binary operator function.
// the binary operators display a natural join semantic.
func NewOperator(op string, operator func(float64, float64) float64) function.MetricFunction {
return function.MetricFunction{
Name: op,
MinArguments: 2,
MaxArguments: 2,
Compute: func(context function.EvaluationContext, args []function.Expression, groups []string) (function.Value, error) {
leftChannel := make(chan function.Value, 1)
rightChannel := make(chan function.Value, 1)
errs := make(chan error, 2)
go func() {
leftValue, err := args[0].Evaluate(context)
leftChannel <- leftValue
errs <- err
}()
go func() {
rightValue, err := args[1].Evaluate(context)
rightChannel <- rightValue
errs <- err
}()
err := <-errs
if err != nil {
return nil, err
}
err = <-errs
if err != nil {
return nil, err
}
leftValue := <-leftChannel
rightValue := <-rightChannel
leftList, err := leftValue.ToSeriesList(context.Timerange)
if err != nil {
return nil, err
}
rightList, err := rightValue.ToSeriesList(context.Timerange)
if err != nil {
return nil, err
}
joined := join.Join([]api.SeriesList{leftList, rightList})
result := make([]api.Timeseries, len(joined.Rows))
for i, row := range joined.Rows {
left := row.Row[0]
right := row.Row[1]
array := make([]float64, len(left.Values))
for j := 0; j < len(left.Values); j++ {
array[j] = operator(left.Values[j], right.Values[j])
}
result[i] = api.Timeseries{array, row.TagSet}
}
return function.SeriesListValue(api.SeriesList{
Series: result,
Timerange: context.Timerange,
Name: fmt.Sprintf("(%s %s %s)", leftValue.GetName(), op, rightValue.GetName()),
}), nil
},
}
}
