From c193b800830a3d7f1faa375616fcc2b4388d4c15 Mon Sep 17 00:00:00 2001
From: Holger Obermaier <40787752+ho-ob@users.noreply.github.com>
Date: Wed, 26 Jan 2022 12:31:04 +0100
Subject: [PATCH] Add documentation

---
 collectors/collectorManager.go | 51 ++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 17 deletions(-)

diff --git a/collectors/collectorManager.go b/collectors/collectorManager.go
index 88cfdf8..192ef31 100644
--- a/collectors/collectorManager.go
+++ b/collectors/collectorManager.go
@@ -6,26 +6,27 @@ import (
 	"sync"
 	"time"
 
+	cclog "github.com/ClusterCockpit/cc-metric-collector/internal/ccLogger"
 	lp "github.com/ClusterCockpit/cc-metric-collector/internal/ccMetric"
 	mct "github.com/ClusterCockpit/cc-metric-collector/internal/multiChanTicker"
-	cclog "github.com/ClusterCockpit/cc-metric-collector/internal/ccLogger"
 )
 
+// Map of all available metric collectors
 var AvailableCollectors = map[string]MetricCollector{
 
-	"likwid":          &LikwidCollector{},
-	"loadavg":         &LoadavgCollector{},
-	"memstat":         &MemstatCollector{},
-	"netstat":         &NetstatCollector{},
-	"ibstat":          &InfinibandCollector{},
-	"lustrestat":      &LustreCollector{},
-	"cpustat":         &CpustatCollector{},
-	"topprocs":        &TopProcsCollector{},
-	"nvidia":          &NvidiaCollector{},
-	"customcmd":       &CustomCmdCollector{},
-	"diskstat":        &DiskstatCollector{},
-	"tempstat":        &TempCollector{},
-	"ipmistat":        &IpmiCollector{},
+	"likwid":          new(LikwidCollector),
+	"loadavg":         new(LoadavgCollector),
+	"memstat":         new(MemstatCollector),
+	"netstat":         new(NetstatCollector),
+	"ibstat":          new(InfinibandCollector),
+	"lustrestat":      new(LustreCollector),
+	"cpustat":         new(CpustatCollector),
+	"topprocs":        new(TopProcsCollector),
+	"nvidia":          new(NvidiaCollector),
+	"customcmd":       new(CustomCmdCollector),
+	"diskstat":        new(DiskstatCollector),
+	"tempstat":        new(TempCollector),
+	"ipmistat":        new(IpmiCollector),
 	"gpfs":            new(GpfsCollector),
 	"cpufreq":         new(CPUFreqCollector),
 	"cpufreq_cpuinfo": new(CPUFreqCpuInfoCollector),
@@ -34,14 +35,15 @@ var AvailableCollectors = map[string]MetricCollector{
 
 type collectorManager struct {
 	collectors []MetricCollector
-	output     chan lp.CCMetric
-	done       chan bool
+	output     chan lp.CCMetric // List of all output channels
+	done       chan bool        // channel to finish / stop metric collector manager
 	ticker     mct.MultiChanTicker
 	duration   time.Duration
 	wg         *sync.WaitGroup
 	config     map[string]json.RawMessage
 }
 
+// Metric collector access functions
 type CollectorManager interface {
 	Init(ticker mct.MultiChanTicker, duration time.Duration, wg *sync.WaitGroup, collectConfigFile string) error
 	AddOutput(output chan lp.CCMetric)
@@ -49,6 +51,13 @@ type CollectorManager interface {
 	Close()
 }
 
+// Init initializes a new metric collector manager by setting up:
+// * output channels
+// * done channel
+// * wait group synchronization (from variable wg)
+// * ticker (from variable ticker)
+// * configuration (read from config file in variable collectConfigFile)
+// Initialization is done for all configured collectors
 func (cm *collectorManager) Init(ticker mct.MultiChanTicker, duration time.Duration, wg *sync.WaitGroup, collectConfigFile string) error {
 	cm.collectors = make([]MetricCollector, 0)
 	cm.output = nil
@@ -56,6 +65,8 @@ func (cm *collectorManager) Init(ticker mct.MultiChanTicker, duration time.Durat
 	cm.wg = wg
 	cm.ticker = ticker
 	cm.duration = duration
+
+	// Read collector config file
 	configFile, err := os.Open(collectConfigFile)
 	if err != nil {
 		cclog.Error(err.Error())
@@ -68,6 +79,8 @@ func (cm *collectorManager) Init(ticker mct.MultiChanTicker, duration time.Durat
 		cclog.Error(err.Error())
 		return err
 	}
+
+	// Initialize configured collectors
 	for k, cfg := range cm.config {
 		if _, found := AvailableCollectors[k]; !found {
 			cclog.ComponentError("CollectorManager", "SKIP unknown collector", k)
@@ -86,6 +99,7 @@ func (cm *collectorManager) Init(ticker mct.MultiChanTicker, duration time.Durat
 	return nil
 }
 
+// Start starts the metric collector manager
 func (cm *collectorManager) Start() {
 	cm.wg.Add(1)
 	tick := make(chan time.Time)
@@ -113,7 +127,7 @@ func (cm *collectorManager) Start() {
 						cclog.ComponentDebug("CollectorManager", "DONE")
 						break CollectorManagerInputLoop
 					default:
-					    cclog.ComponentDebug("CollectorManager", c.Name(), t)
+						cclog.ComponentDebug("CollectorManager", c.Name(), t)
 						c.Read(cm.duration, cm.output)
 					}
 				}
@@ -123,15 +137,18 @@ func (cm *collectorManager) Start() {
 	cclog.ComponentDebug("CollectorManager", "STARTED")
 }
 
+// AddOutput adds the output channel to the metric collector manager
 func (cm *collectorManager) AddOutput(output chan lp.CCMetric) {
 	cm.output = output
 }
 
+// Close finishes / stops the metric collector manager
 func (cm *collectorManager) Close() {
 	cm.done <- true
 	cclog.ComponentDebug("CollectorManager", "CLOSE")
 }
 
+// New creates a new initialized metric collector manager
 func New(ticker mct.MultiChanTicker, duration time.Duration, wg *sync.WaitGroup, collectConfigFile string) (CollectorManager, error) {
 	cm := &collectorManager{}
 	err := cm.Init(ticker, duration, wg, collectConfigFile)