48 lines
933 B
Go
48 lines
933 B
Go
package main
|
|
|
|
import (
|
|
"log"
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
"git.smarteching.com/zeni/go-chart/v2"
|
|
)
|
|
|
|
var lock sync.Mutex
|
|
var graph *chart.Chart
|
|
var ts *chart.TimeSeries
|
|
|
|
func addData(t time.Time, e time.Duration) {
|
|
lock.Lock()
|
|
ts.XValues = append(ts.XValues, t)
|
|
ts.YValues = append(ts.YValues, chart.TimeMillis(e))
|
|
lock.Unlock()
|
|
}
|
|
|
|
func drawChart(res http.ResponseWriter, req *http.Request) {
|
|
start := time.Now()
|
|
defer func() {
|
|
addData(start, time.Since(start))
|
|
}()
|
|
if len(ts.XValues) == 0 {
|
|
http.Error(res, "no data (yet)", http.StatusBadRequest)
|
|
return
|
|
}
|
|
res.Header().Set("Content-Type", "image/png")
|
|
if err := graph.Render(chart.PNG, res); err != nil {
|
|
log.Printf("%v", err)
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
ts = &chart.TimeSeries{
|
|
XValues: []time.Time{},
|
|
YValues: []float64{},
|
|
}
|
|
graph = &chart.Chart{
|
|
Series: []chart.Series{ts},
|
|
}
|
|
http.HandleFunc("/", drawChart)
|
|
log.Fatal(http.ListenAndServe(":8080", nil))
|
|
}
|