From 1c80ad5f5a7926b7ed1dd0892899e88aa0868a41 Mon Sep 17 00:00:00 2001
From: Eduard Marbach <mail@eduard-marbach.de>
Date: Wed, 30 Oct 2024 11:07:26 +0100
Subject: [PATCH] feat: add tick feature

---
 README.md | 23 ++++++++++++++++++++++-
 main.go   | 37 ++++++++++++++++++++++++++++++-------
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 9dc7ef9..4bf67c8 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,23 @@
 # prometheus_turbotstat_exporter
-An prometheus exporter for turbotstat (for monitoring different C-states and pkg-states)
+An prometheus exporter for turbotstat (for monitoring different C-states and pkg-states).
+
+## Example scrape output
+
+Part of the output from the scrape:
+
+```txt
+...
+turbostat_cpu_states_percent{num_cpu="6",type="c1e"} 0.03
+turbostat_cpu_states_percent{num_cpu="6",type="c3"} 0.05
+turbostat_cpu_states_percent{num_cpu="6",type="c6"} 1.37
+turbostat_cpu_states_percent{num_cpu="6",type="c7s"} 0
+turbostat_cpu_states_percent{num_cpu="6",type="c8"} 1.11
+turbostat_cpu_states_percent{num_cpu="6",type="c9"} 0.13
+turbostat_cpu_states_percent{num_cpu="6",type="poll"} 0
+turbostat_cpu_states_percent{num_cpu="7",type="c1"} 0.01
+turbostat_cpu_states_percent{num_cpu="7",type="c10"} 96.91
+turbostat_cpu_states_percent{num_cpu="7",type="c1e"} 0.03
+turbostat_cpu_states_percent{num_cpu="7",type="c3"} 0.01
+turbostat_cpu_states_percent{num_cpu="7",type="c6"} 1.36
+...
+```
diff --git a/main.go b/main.go
index 03f1dc3..fcf65b9 100644
--- a/main.go
+++ b/main.go
@@ -12,6 +12,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"time"
 
 	"bufio"
 
@@ -400,7 +401,6 @@ func parseOutput(input io.Reader) ([]string, []map[string]interface{}) {
 }
 
 func Update() {
-	// TODO maybe run the execution in the background and just return the current values?
 	reader := executeProgram(defaultSleepTimer)
 	_, data := parseOutput(&reader)
 
@@ -437,12 +437,14 @@ func Update() {
 type helloWorldhandler struct{}
 
 func (h helloWorldhandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	Update()
+	if !isBackgroundMode {
+		Update()
+	}
 	promhttp.Handler().ServeHTTP(w, r)
 }
 
 var listOfMetrics []metricMapping = nil
-var defaultSleepTimer int = 5
+var defaultSleepTimer = 5
 var isCommandCat = false
 var isBackgroundMode = false
 var backgroundCollectSeconds = 30
@@ -514,6 +516,31 @@ func main() {
 
 	listOfMetrics = buildMetricList(&reader)
 
+	if isBackgroundMode {
+		log.Debugf("Starting ticker")
+		ticker := time.NewTicker(time.Duration(backgroundCollectSeconds) * time.Second)
+		quit := make(chan struct{})
+		manualTick := make(chan bool)
+
+		go func() {
+			for {
+				select {
+				case <-ticker.C:
+					log.Debugf("Ticker update")
+					Update()
+				case <-manualTick:
+					log.Debugf("Manual tick update")
+					Update()
+				case <-quit:
+					log.Debugf("Stop background updater")
+					ticker.Stop()
+					return
+				}
+			}
+		}()
+		manualTick <- true
+	}
+
 	//foo := newFooCollector()
 
 	http.Handle("/metrics", helloWorldhandler{})
@@ -555,10 +582,6 @@ func test1() {
 		panic(err)
 	}
 
-	if err != nil { // Load clients from file
-		panic(err)
-	}
-
 	for _, client := range maps {
 		fmt.Println("Hello", client)
 	}