From d4cb49b02d0f0e67c42f5ef94dfaad28d35d3bd9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Serhat=20=C5=9Eevki=20Din=C3=A7er?= <jfcgauss@gmail.com>
Date: Sat, 7 May 2022 03:46:06 +0300
Subject: [PATCH] :bar_chart: add refresh period to monitor mw

---
 middleware/monitor/README.md       |  6 +++
 middleware/monitor/config.go       | 52 +++++++++++---------
 middleware/monitor/index.go        | 76 +++++++++++++++---------------
 middleware/monitor/monitor.go      |  4 +-
 middleware/monitor/monitor_test.go | 30 ++++++++++--
 5 files changed, 104 insertions(+), 64 deletions(-)

diff --git a/middleware/monitor/README.md b/middleware/monitor/README.md
index 671e3c7352..8ac23e4211 100644
--- a/middleware/monitor/README.md
+++ b/middleware/monitor/README.md
@@ -48,6 +48,11 @@ type Config struct {
 	// Optional. Default: "Fiber Monitor"
 	Title string
 
+	// Refresh period
+	//
+	// Optional. Default: 3 seconds
+	Refresh time.Duration
+
 	// To disable serving HTML, you can make true this option.
 	//
 	// Optional. Default: false
@@ -65,6 +70,7 @@ type Config struct {
 ```go
 var ConfigDefault = Config{
 	Title:   "Fiber Monitor",
+	Refresh: 3 * time.Second,
 	APIOnly: false,
 	Next:    nil,
 }
diff --git a/middleware/monitor/config.go b/middleware/monitor/config.go
index b98f73d4e7..dbd3186835 100644
--- a/middleware/monitor/config.go
+++ b/middleware/monitor/config.go
@@ -1,7 +1,7 @@
 package monitor
 
 import (
-	"strings"
+	"time"
 
 	"github.com/gofiber/fiber/v2"
 )
@@ -13,6 +13,11 @@ type Config struct {
 	// Optional. Default: "Fiber Monitor"
 	Title string
 
+	// Refresh period
+	//
+	// Optional. Default: 3 seconds
+	Refresh time.Duration
+
 	// Whether the service should expose only the monitoring API.
 	//
 	// Optional. Default: false
@@ -23,33 +28,28 @@ type Config struct {
 	// Optional. Default: nil
 	Next func(c *fiber.Ctx) bool
 
-	// defaultTitle substituted with Title in indexHtml
+	// customized indexHtml
 	index string
 }
 
-var prevTitle = defaultTitle
-
 var ConfigDefault = Config{
 	Title:   defaultTitle,
+	Refresh: defaultRefresh,
 	APIOnly: false,
 	Next:    nil,
-	index:   indexHtml,
-}
-
-func newIndex(title string) string {
-	if title == defaultTitle {
-		return indexHtml
-	}
-	return strings.ReplaceAll(indexHtml, defaultTitle, title)
+	index:   newIndex(defaultTitle, defaultRefresh),
 }
 
 func configDefault(config ...Config) Config {
-	// Users can change ConfigDefault.Title which then
-	// becomes incompatible with ConfigDefault.index
-	if prevTitle != ConfigDefault.Title {
-		prevTitle = ConfigDefault.Title
-		// update default index with new default title
-		ConfigDefault.index = newIndex(prevTitle)
+	// Users can change ConfigDefault.Title/Refresh which then
+	// become incompatible with ConfigDefault.index
+	if ConfigDefault.Title != defaultTitle || ConfigDefault.Refresh != defaultRefresh {
+
+		if ConfigDefault.Refresh < minRefresh {
+			ConfigDefault.Refresh = minRefresh
+		}
+		// update default index with new default title/refresh
+		ConfigDefault.index = newIndex(ConfigDefault.Title, ConfigDefault.Refresh)
 	}
 
 	// Return default config if nothing provided
@@ -61,12 +61,22 @@ func configDefault(config ...Config) Config {
 	cfg := config[0]
 
 	// Set default values
-	if cfg.Title == "" || cfg.Title == ConfigDefault.Title {
+	if cfg.Title == "" {
 		cfg.Title = ConfigDefault.Title
+	}
+
+	if cfg.Refresh == 0 {
+		cfg.Refresh = ConfigDefault.Refresh
+	}
+
+	if cfg.Title == ConfigDefault.Title && cfg.Refresh == ConfigDefault.Refresh {
 		cfg.index = ConfigDefault.index
 	} else {
-		// update cfg.index with new title
-		cfg.index = newIndex(cfg.Title)
+		if cfg.Refresh < minRefresh {
+			cfg.Refresh = minRefresh
+		}
+		// update cfg.index with custom title/refresh
+		cfg.index = newIndex(cfg.Title, cfg.Refresh)
 	}
 
 	if cfg.Next == nil {
diff --git a/middleware/monitor/index.go b/middleware/monitor/index.go
index 6313685290..4267b7c4e2 100644
--- a/middleware/monitor/index.go
+++ b/middleware/monitor/index.go
@@ -1,8 +1,32 @@
 package monitor
 
+import (
+	"strconv"
+	"strings"
+	"time"
+)
+
+// returns index with new title/refresh
+func newIndex(title string, refresh time.Duration) string {
+
+	timeout := refresh.Milliseconds() - timeoutDiff
+	if timeout < timeoutDiff {
+		timeout = timeoutDiff
+	}
+	ts := strconv.FormatInt(timeout, 10)
+
+	index := strings.ReplaceAll(indexHtml, "$TITLE", title)
+	return strings.ReplaceAll(index, "$TIMEOUT", ts)
+}
+
 const (
 	defaultTitle = "Fiber Monitor"
 
+	defaultRefresh = 3 * time.Second
+	timeoutDiff    = 200 // timeout will be Refresh (in millisconds) - timeoutDiff
+	minRefresh     = timeoutDiff * time.Millisecond
+
+	// parametrized by $TITLE and $TIMEOUT
 	indexHtml = `<!DOCTYPE html>
 <html lang="en">
 <head>
@@ -10,7 +34,7 @@ const (
 	<meta name="viewport" content="width=device-width, initial-scale=1.0">
 	<link href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;900&display=swap" rel="stylesheet">
 	<script src="https://cdn.jsdelivr.net/npm/chart.js@2.9/dist/Chart.bundle.min.js"></script>
-	<title>` + defaultTitle + `</title>
+	<title>$TITLE</title>
 <style>
 	body {
 		margin: 0;
@@ -35,12 +59,8 @@ const (
 		margin-bottom: 20px;
 		align-items: center;
 	}
-	.row .column:first-child {
-		width: 35%;
-	}
-	.row .column:last-child {
-		width: 65%;
-	}
+	.row .column:first-child { width: 35%; }
+	.row .column:last-child { width: 65%; }
 	.metric {
 		color: #777;
 		font-weight: 900;
@@ -54,12 +74,8 @@ const (
 		font-size: 12px;
 		color: #777;
 	}
-	h2 span.ram_os {
-		color: rgba(255, 150, 0, .8);
-	}
-	h2 span.ram_total {
-		color: rgba(0, 200, 0, .8);
-	}
+	h2 span.ram_os { color: rgba(255, 150, 0, .8); }
+	h2 span.ram_total { color: rgba(0, 200, 0, .8); }
 	canvas {
 		width: 200px;
 		height: 180px;
@@ -68,7 +84,7 @@ const (
 </head>
 <body>
 	<section class="wrapper">
-	<div class="title"><h1>` + defaultTitle + `</h1></div>
+	<div class="title"><h1>$TITLE</h1></div>
 	<section class="charts">
 		<div class="row">
 			<div class="column">
@@ -130,25 +146,17 @@ const (
 
 	const options = {
 		scales: {
-			yAxes: [{
-				ticks: {
-					beginAtZero: true
-				}
-			}],
+			yAxes: [{ ticks: { beginAtZero: true }}],
 			xAxes: [{
 				type: 'time',
 				time: {
 					unitStepSize: 30,
 					unit: 'second'
 				},
-				gridlines: {
-					display: false
-				}
+				gridlines: { display: false }
 			}]
 		},
-		tooltips: {
-			enabled: false
-		},
+		tooltips: {	enabled: false },
 		responsive: true,
 		maintainAspectRatio: false,
 		animation: false
@@ -204,7 +212,8 @@ const (
 		cpuOS = json.os.cpu.toFixed(1);
 
 		cpuMetric.innerHTML = cpu + '% <span>' + cpuOS + '%</span>';
-		ramMetric.innerHTML = formatBytes(json.pid.ram) + '<span> / </span><span class="ram_os">' + formatBytes(json.os.ram) + '<span><span> / </span><span class="ram_total">' + formatBytes(json.os.total_ram) + '</span>';
+		ramMetric.innerHTML = formatBytes(json.pid.ram) + '<span> / </span><span class="ram_os">' + formatBytes(json.os.ram) +
+			'<span><span> / </span><span class="ram_total">' + formatBytes(json.os.total_ram) + '</span>';
 		rtimeMetric.innerHTML = rtime + 'ms <span>client</span>';
 		connsMetric.innerHTML = json.pid.conns + ' <span>' + json.os.conns + '</span>';
 
@@ -219,33 +228,26 @@ const (
 
 		charts.forEach(chart => {
 			if (chart.data.labels.length > 50) {
-				chart.data.datasets.forEach(function (dataset) {
-					dataset.data.shift();
-				});
+				chart.data.datasets.forEach(function (dataset) { dataset.data.shift(); });
 				chart.data.labels.shift();
 			}
-
 			chart.data.labels.push(timestamp);
 			chart.update();
 		});
-		setTimeout(fetchJSON, 750)
+		setTimeout(fetchJSON, $TIMEOUT)
 	}
 	function fetchJSON() {
 		var t1 = ''
 		var t0 = performance.now()
 		fetch(window.location.href, {
-				headers: {
-					'Accept': 'application/json'
-				},
+				headers: { 'Accept': 'application/json' },
 				credentials: 'same-origin'
 			})
 			.then(res => {
 				t1 = performance.now()
 				return res.json()
 			})
-			.then(res => {
-				update(res, Math.round(t1 - t0))
-			})
+			.then(res => { update(res, Math.round(t1 - t0)) })
 			.catch(console.error);
 	}
 	fetchJSON()
diff --git a/middleware/monitor/monitor.go b/middleware/monitor/monitor.go
index cd1f3705d1..729bc00988 100644
--- a/middleware/monitor/monitor.go
+++ b/middleware/monitor/monitor.go
@@ -64,9 +64,9 @@ func New(config ...Config) fiber.Handler {
 
 		go func() {
 			for {
-				updateStatistics(p)
+				time.Sleep(cfg.Refresh)
 
-				time.Sleep(1 * time.Second)
+				updateStatistics(p)
 			}
 		}()
 	})
diff --git a/middleware/monitor/monitor_test.go b/middleware/monitor/monitor_test.go
index 0573fe879c..6fd4d654c6 100644
--- a/middleware/monitor/monitor_test.go
+++ b/middleware/monitor/monitor_test.go
@@ -2,9 +2,11 @@ package monitor
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"net/http/httptest"
 	"testing"
+	"time"
 
 	"github.com/gofiber/fiber/v2"
 	"github.com/gofiber/fiber/v2/utils"
@@ -28,16 +30,36 @@ func Test_Monitor_Html(t *testing.T) {
 
 	app := fiber.New()
 
+	// defaults
 	app.Get("/", New())
-
 	resp, err := app.Test(httptest.NewRequest(fiber.MethodGet, "/", nil))
+
 	utils.AssertEqual(t, nil, err)
 	utils.AssertEqual(t, 200, resp.StatusCode)
-	utils.AssertEqual(t, fiber.MIMETextHTMLCharsetUTF8, resp.Header.Get(fiber.HeaderContentType))
+	utils.AssertEqual(t, fiber.MIMETextHTMLCharsetUTF8,
+		resp.Header.Get(fiber.HeaderContentType))
+	buf, err := ioutil.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, true, bytes.Contains(buf, []byte("<title>"+defaultTitle+"</title>")))
+	timeoutLine := fmt.Sprintf("setTimeout(fetchJSON, %d)",
+		defaultRefresh.Milliseconds()-timeoutDiff)
+	utils.AssertEqual(t, true, bytes.Contains(buf, []byte(timeoutLine)))
 
-	b, err := ioutil.ReadAll(resp.Body)
+	// custom config
+	conf := Config{Title: "New " + defaultTitle, Refresh: defaultRefresh + time.Second}
+	app.Get("/custom", New(conf))
+	resp, err = app.Test(httptest.NewRequest(fiber.MethodGet, "/custom", nil))
+
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 200, resp.StatusCode)
+	utils.AssertEqual(t, fiber.MIMETextHTMLCharsetUTF8,
+		resp.Header.Get(fiber.HeaderContentType))
+	buf, err = ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err)
-	utils.AssertEqual(t, true, bytes.Contains(b, []byte("<title>"+defaultTitle+"</title>")))
+	utils.AssertEqual(t, true, bytes.Contains(buf, []byte("<title>"+conf.Title+"</title>")))
+	timeoutLine = fmt.Sprintf("setTimeout(fetchJSON, %d)",
+		conf.Refresh.Milliseconds()-timeoutDiff)
+	utils.AssertEqual(t, true, bytes.Contains(buf, []byte(timeoutLine)))
 }
 
 // go test -run Test_Monitor_JSON -race