2017-03-31 18:01:58 +02:00

66 lines
1.9 KiB
Go

package teststat
import (
"bufio"
"bytes"
"io"
"regexp"
"strconv"
"github.com/go-kit/kit/metrics/generic"
)
// SumLines expects a regex whose first capture group can be parsed as a
// float64. It will dump the WriterTo and parse each line, expecting to find a
// match. It returns the sum of all captured floats.
func SumLines(w io.WriterTo, regex string) func() float64 {
return func() float64 {
sum, _ := stats(w, regex, nil)
return sum
}
}
// LastLine expects a regex whose first capture group can be parsed as a
// float64. It will dump the WriterTo and parse each line, expecting to find a
// match. It returns the final captured float.
func LastLine(w io.WriterTo, regex string) func() float64 {
return func() float64 {
_, final := stats(w, regex, nil)
return final
}
}
// Quantiles expects a regex whose first capture group can be parsed as a
// float64. It will dump the WriterTo and parse each line, expecting to find a
// match. It observes all captured floats into a generic.Histogram with the
// given number of buckets, and returns the 50th, 90th, 95th, and 99th quantiles
// from that histogram.
func Quantiles(w io.WriterTo, regex string, buckets int) func() (float64, float64, float64, float64) {
return func() (float64, float64, float64, float64) {
h := generic.NewHistogram("quantile-test", buckets)
stats(w, regex, h)
return h.Quantile(0.50), h.Quantile(0.90), h.Quantile(0.95), h.Quantile(0.99)
}
}
func stats(w io.WriterTo, regex string, h *generic.Histogram) (sum, final float64) {
re := regexp.MustCompile(regex)
buf := &bytes.Buffer{}
w.WriteTo(buf)
//fmt.Fprintf(os.Stderr, "%s\n", buf.String())
s := bufio.NewScanner(buf)
for s.Scan() {
match := re.FindStringSubmatch(s.Text())
f, err := strconv.ParseFloat(match[1], 64)
if err != nil {
panic(err)
}
sum += f
final = f
if h != nil {
h.Observe(f)
}
}
return sum, final
}