cc-metric-store/internal/memorystore/stats.go
2024-05-06 14:20:43 +02:00

121 lines
2.6 KiB
Go

package memorystore
import (
"errors"
"math"
"github.com/ClusterCockpit/cc-metric-store/internal/config"
"github.com/ClusterCockpit/cc-metric-store/internal/util"
)
type Stats struct {
Samples int
Avg util.Float
Min util.Float
Max util.Float
}
func (b *buffer) stats(from, to int64) (Stats, int64, int64, error) {
if from < b.start {
if b.prev != nil {
return b.prev.stats(from, to)
}
from = b.start
}
// TODO: Check if b.closed and if so and the full buffer is queried,
// use b.statistics instead of iterating over the buffer.
samples := 0
sum, min, max := 0.0, math.MaxFloat32, -math.MaxFloat32
var t int64
for t = from; t < to; t += b.frequency {
idx := int((t - b.start) / b.frequency)
if idx >= cap(b.data) {
b = b.next
if b == nil {
break
}
idx = 0
}
if t < b.start || idx >= len(b.data) {
continue
}
xf := float64(b.data[idx])
if math.IsNaN(xf) {
continue
}
samples += 1
sum += xf
min = math.Min(min, xf)
max = math.Max(max, xf)
}
return Stats{
Samples: samples,
Avg: util.Float(sum) / util.Float(samples),
Min: util.Float(min),
Max: util.Float(max),
}, from, t, nil
}
// Returns statistics for the requested metric on the selected node/level.
// Data is aggregated to the selected level the same way as in `MemoryStore.Read`.
// If `Stats.Samples` is zero, the statistics should not be considered as valid.
func (m *MemoryStore) Stats(selector util.Selector, metric string, from, to int64) (*Stats, int64, int64, error) {
if from > to {
return nil, 0, 0, errors.New("invalid time range")
}
minfo, ok := m.Metrics[metric]
if !ok {
return nil, 0, 0, errors.New("unkown metric: " + metric)
}
n, samples := 0, 0
avg, min, max := util.Float(0), math.MaxFloat32, -math.MaxFloat32
err := m.root.findBuffers(selector, minfo.Offset, func(b *buffer) error {
stats, cfrom, cto, err := b.stats(from, to)
if err != nil {
return err
}
if n == 0 {
from, to = cfrom, cto
} else if from != cfrom || to != cto {
return ErrDataDoesNotAlign
}
samples += stats.Samples
avg += stats.Avg
min = math.Min(min, float64(stats.Min))
max = math.Max(max, float64(stats.Max))
n += 1
return nil
})
if err != nil {
return nil, 0, 0, err
}
if n == 0 {
return nil, 0, 0, ErrNoData
}
if minfo.Aggregation == config.AvgAggregation {
avg /= util.Float(n)
} else if n > 1 && minfo.Aggregation != config.SumAggregation {
return nil, 0, 0, errors.New("invalid aggregation")
}
return &Stats{
Samples: samples,
Avg: avg,
Min: util.Float(min),
Max: util.Float(max),
}, from, to, nil
}