Go の `expfmt` パッケージを使用して Prometheus Exposition 形式のデータを効率的に解析するにはどうすればよいですか?

package main

import (
    expfmt "github.com/prometheus/common/expfmt"
    dto "github.com/prometheus/client_model/go"
    "fmt"
    "os"
)

func main() {
    // Parse the Prometheus data from a file
    mf, err := parseMF("path/to/file.txt")
    if err != nil {
        fmt.Println(err)
        return
    }

    // Iterate over the metric families
    for k, v := range mf {
        fmt.Printf("KEY: %s\n", k)
        fmt.Printf("VAL: %+v\n", v)
    }
}

func parseMF(path string) (map[string]*dto.MetricFamily, error) {
    reader, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer reader.Close()

    // Use the expfmt parser to parse the data
    var parser expfmt.TextParser
    mf, err := parser.TextToMetricFamilies(reader)
    if err != nil {
        return nil, err
    }
    return mf, nil
}

# HELP net_conntrack_dialer_conn_attempted_total
# TYPE net_conntrack_dialer_conn_attempted_total untyped
net_conntrack_dialer_conn_attempted_total{dialer_name="federate",instance="localhost:9090",job="prometheus"} 1 1608520832877

KEY:  net_conntrack_dialer_conn_attempted_total
VAL:  name: "net_conntrack_dialer_conn_attempted_total" type: UNTYPED metric:<label:<name: "dialer_name" value: "federate" > label:<name: "instance" value: "localhost:9090" > label:<name: "job" value: "prometheus" > untyped:<value: 1 > timestamp_ms: 1608520832877 >