79 lines
1.8 KiB
Go
79 lines
1.8 KiB
Go
// Usage: http://localhost:8080?series=100&values=1000
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package main
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import (
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"fmt"
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"math/rand"
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"net/http"
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"strconv"
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"time"
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chart "github.com/wcharczuk/go-chart"
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)
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func random(min, max float64) float64 {
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return rand.Float64()*(max-min) + min
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}
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func drawLargeChart(res http.ResponseWriter, r *http.Request) {
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numSeriesInt64, err := strconv.ParseInt(r.FormValue("series"), 10, 64)
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if err != nil {
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numSeriesInt64 = int64(1)
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}
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if numSeriesInt64 == 0 {
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numSeriesInt64 = 1
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}
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numSeries := int(numSeriesInt64)
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numValuesInt64, err := strconv.ParseInt(r.FormValue("values"), 10, 64)
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if err != nil {
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numValuesInt64 = int64(100)
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}
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if numValuesInt64 == 0 {
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numValuesInt64 = int64(100)
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}
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numValues := int(numValuesInt64)
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series := make([]chart.Series, numSeries)
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for i := 0; i < numSeries; i++ {
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xValues := make([]time.Time, numValues)
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yValues := make([]float64, numValues)
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for j := 0; j < numValues; j++ {
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xValues[j] = time.Now().AddDate(0, 0, (numValues-j)*-1)
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yValues[j] = random(float64(-500), float64(500))
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}
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series[i] = chart.TimeSeries{
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Name: fmt.Sprintf("aaa.bbb.hostname-%v.ccc.ddd.eee.fff.ggg.hhh.iii.jjj.kkk.lll.mmm.nnn.value", i),
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XValues: xValues,
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YValues: yValues,
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}
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}
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graph := chart.Chart{
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XAxis: chart.XAxis{
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Name: "Time",
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NameStyle: chart.StyleShow(),
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Style: chart.StyleShow(),
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},
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YAxis: chart.YAxis{
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Name: "Value",
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NameStyle: chart.StyleShow(),
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Style: chart.StyleShow(),
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},
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Series: series,
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}
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res.Header().Set("Content-Type", "image/png")
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graph.Render(chart.PNG, res)
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}
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func main() {
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http.HandleFunc("/", drawLargeChart)
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http.HandleFunc("/favico.ico", func(res http.ResponseWriter, req *http.Request) {
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res.Write([]byte{})
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})
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http.ListenAndServe(":8080", nil)
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}
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