ssube/prometheus-sql-adapter

package metric

import (
    "encoding/binary"
    "encoding/json"
    "errors"
    "strings"

    uuid "github.com/nu7hatch/gouuid"
    "github.com/prometheus/common/model"
)

// Batch of metrics
type Metrics []*model.Metric

// FilterMetric based on name label and list of allowed name prefixes
func FilterMetric(m *model.Metric, allowedNames []string) bool {
    if m == nil {
        return false
    }

    name := GetName(*m)
    for _, n := range allowedNames {
        if strings.HasPrefix(name, n) {
            return true
        }
    }

    return false
}

// GetName label from a metric
func GetName(m model.Metric) string {
    return string(m[model.MetricNameLabel])
}

// MakeLid extracts the lid hash from a metric
func MakeLid(m *model.Metric) (string, error) {
    if m == nil {
        return "", errors.New("missing metric")
    }

    buf := make([]byte, 16)
    binary.LittleEndian.PutUint64(buf[0:], 0)
    binary.LittleEndian.PutUint64(buf[8:], uint64(m.Fingerprint()))

    u, err := uuid.Parse(buf)
    if err != nil {
        return "", err
    }

    return u.String(), nil
}

// MakeLidName extracts both the lid hash and name label from a metric
func MakeLidName(m model.Metric) (string, string, error) {
    lid, err := MakeLid(&m)
    if err != nil {
        return "", "", err
    }
    return lid, GetName(m), nil
}

// MarshalMetric to JSON
func MarshalMetric(m *model.Metric) (string, error) {
    buf, err := json.Marshal(m)
    if err != nil {
        return "", err
    }
    return string(buf), nil
}