func (m *sequentialMultiBackend) FetchMultipleSeries(request api.FetchMultipleRequest) (api.SeriesList, error) {
series := make([]api.Timeseries, len(request.Metrics))
var err error = nil
for i, metric := range request.Metrics {
series[i], err = m.Backend.FetchSingleSeries(request.ToSingle(metric))
if err != nil {
return api.SeriesList{}, err
}
}
return api.SeriesList{
Series: series,
Timerange: request.Timerange,
}, nil
}
func (m *parallelMultiBackend) FetchMultipleSeries(request api.FetchMultipleRequest) (api.SeriesList, error) {
works := make([]func() (api.Timeseries, error), len(request.Metrics))
for i, metric := range request.Metrics {
// Since we want to create a closure, we want to close over this particular metric,
// rather than the variable itself (which is the same between iterations).
// We accomplish this here:
metric := metric
works[i] = func() (api.Timeseries, error) {
return m.Backend.FetchSingleSeries(request.ToSingle(metric))
}
}
resultSeries, err := m.fetchManyLazy(request.Cancellable, works)
if err != nil {
return api.SeriesList{}, err
}
return api.SeriesList{
Series: resultSeries,
Timerange: request.Timerange,
}, nil
}