firehol/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package nsd

import (
    "bufio"
    "bytes"
    "errors"
    "strconv"
    "strings"
)

func (n *Nsd) collect() (map[string]int64, error) {
    stats, err := n.exec.stats()
    if err != nil {
        return nil, err
    }

    if len(stats) == 0 {
        return nil, errors.New("empty stats response")
    }

    mx := make(map[string]int64)

    sc := bufio.NewScanner(bytes.NewReader(stats))

    for sc.Scan() {
        n.collectStatsLine(mx, sc.Text())
    }

    if len(mx) == 0 {
        return nil, errors.New("unexpected stats response: no metrics found")
    }

    addMissingMetrics(mx, "num.rcode.", answerRcodes)
    addMissingMetrics(mx, "num.opcode.", queryOpcodes)
    addMissingMetrics(mx, "num.class.", queryClasses)
    addMissingMetrics(mx, "num.type.", queryTypes)

    return mx, nil
}

func (n *Nsd) collectStatsLine(mx map[string]int64, line string) {
    if line = strings.TrimSpace(line); line == "" {
        return
    }

    key, value, ok := strings.Cut(line, "=")
    if !ok {
        n.Debugf("invalid line in stats: '%s'", line)
        return
    }

    var v int64
    var f float64
    var err error

    switch key {
    case "time.boot":
        f, err = strconv.ParseFloat(value, 64)
        v = int64(f)
    default:
        v, err = strconv.ParseInt(value, 10, 64)
    }

    if err != nil {
        n.Debugf("invalid value in stats line '%s': '%s'", line, value)
        return
    }

    mx[key] = v
}

func addMissingMetrics(mx map[string]int64, prefix string, values []string) {
    for _, v := range values {
        k := prefix + v
        if _, ok := mx[k]; !ok {
            mx[k] = 0
        }
    }
}