From fd2c7d264af4406202a383c96998ea799ba43306 Mon Sep 17 00:00:00 2001
From: Marcel Fest <marcel.fest@telekom.de>
Date: Tue, 23 Apr 2024 16:39:05 +0200
Subject: [PATCH] Reduce logical complexity

---
 pkg/monitoring/collector.go | 12 ++----------
 pkg/monitoring/frr.go       | 33 +++------------------------------
 pkg/monitoring/nl.go        | 32 ++------------------------------
 3 files changed, 7 insertions(+), 70 deletions(-)

diff --git a/pkg/monitoring/collector.go b/pkg/monitoring/collector.go
index eb18302e..d7e17bcb 100644
--- a/pkg/monitoring/collector.go
+++ b/pkg/monitoring/collector.go
@@ -46,18 +46,10 @@ type typedFactoryDesc struct {
 }
 
 type basicCollector struct {
-	name     string
-	mu       sync.Mutex
-	wg       sync.WaitGroup
-	channels []chan<- prometheus.Metric
-	logger   logr.Logger
+	name   string
+	logger logr.Logger
 }
 
-// only use with Lock called before.
-func (c *basicCollector) clearChannels() {
-	defer c.mu.Unlock()
-	c.channels = []chan<- prometheus.Metric{}
-}
 func (d *typedFactoryDesc) mustNewConstMetric(value float64, labels ...string) prometheus.Metric {
 	return prometheus.MustNewConstMetric(d.desc, d.valueType, value, labels...)
 }
diff --git a/pkg/monitoring/frr.go b/pkg/monitoring/frr.go
index abd2991d..9c5df27c 100644
--- a/pkg/monitoring/frr.go
+++ b/pkg/monitoring/frr.go
@@ -3,7 +3,6 @@ package monitoring
 import (
 	"strconv"
 	"strings"
-	"sync"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/telekom/das-schiff-network-operator/pkg/frr"
@@ -239,36 +238,10 @@ func (c *frrCollector) updateBGPNeighbors(ch chan<- prometheus.Metric, bgpNeighb
 		}
 	}
 }
-func (c *frrCollector) updateChannels(vrfs []frr.VrfVniSpec, routes []route.Information, neighbors frr.BGPVrfSummary) {
-	for _, ch := range c.channels {
-		c.updateVrfs(ch, vrfs)
-		c.updateRoutes(ch, routes)
-		c.updateBGPNeighbors(ch, neighbors)
-	}
-}
 
 func (c *frrCollector) Update(ch chan<- prometheus.Metric) error {
-	c.mu.Lock()
-	c.channels = append(c.channels, ch)
-	if len(c.channels) == 1 {
-		c.wg = sync.WaitGroup{}
-		c.wg.Add(1)
-		// Ensure all other function calls will wait.
-		c.mu.Unlock()
-		routes, neighbors, vrfs := func() ([]route.Information, frr.BGPVrfSummary, []frr.VrfVniSpec) {
-			return c.getRoutes(), c.getBGPNeighbors(), c.getVrfs()
-		}()
-		go func(routes []route.Information, neighbors frr.BGPVrfSummary, vrfs []frr.VrfVniSpec) {
-			c.mu.Lock()
-			// unlock is done after return using defer.
-			defer c.wg.Done()
-			c.updateChannels(vrfs, routes, neighbors)
-		}(routes, neighbors, vrfs)
-		// unlock is done in this function.
-		defer c.clearChannels()
-	} else {
-		c.mu.Unlock()
-	}
-	c.wg.Wait()
+	c.updateVrfs(ch, c.getVrfs())
+	c.updateRoutes(ch, c.getRoutes())
+	c.updateBGPNeighbors(ch, c.getBGPNeighbors())
 	return nil
 }
diff --git a/pkg/monitoring/nl.go b/pkg/monitoring/nl.go
index 078b59f9..aca73c77 100644
--- a/pkg/monitoring/nl.go
+++ b/pkg/monitoring/nl.go
@@ -2,7 +2,6 @@ package monitoring
 
 import (
 	"fmt"
-	"sync"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/telekom/das-schiff-network-operator/pkg/nl"
@@ -80,35 +79,8 @@ func (c *netlinkCollector) updateNeighbors(ch chan<- prometheus.Metric, neighbor
 	}
 }
 
-func (c *netlinkCollector) updateChannels(neighbors []nl.NeighborInformation, routes []route.Information) {
-	for _, ch := range c.channels {
-		c.updateNeighbors(ch, neighbors)
-		c.updateRoutes(ch, routes)
-	}
-}
-
 func (c *netlinkCollector) Update(ch chan<- prometheus.Metric) error {
-	c.mu.Lock()
-	c.channels = append(c.channels, ch)
-	if len(c.channels) == 1 {
-		c.wg = sync.WaitGroup{}
-		c.wg.Add(1)
-		// Ensure all other function calls will wait.
-		c.mu.Unlock()
-		routes, neighbors := func() ([]route.Information, []nl.NeighborInformation) {
-			return c.getRoutes(), c.getNeighbors()
-		}()
-		go func(routes []route.Information, neighbors []nl.NeighborInformation) {
-			c.mu.Lock()
-			// unlock is done after return using defer.
-			defer c.wg.Done()
-			c.updateChannels(neighbors, routes)
-		}(routes, neighbors)
-		// unlock is done in this function.
-		defer c.clearChannels()
-	} else {
-		c.mu.Unlock()
-	}
-	c.wg.Wait()
+	c.updateNeighbors(ch, c.getNeighbors())
+	c.updateRoutes(ch, c.getRoutes())
 	return nil
 }