feat: add log coupling for hostsensorutils

Signed-off-by: Alessio Greggi <ale_grey_91@hotmail.it>

core/pkg/hostsensorutils/log_coupling.go

@@ -0,0 +1,51 @@
+package hostsensorutils
+
+import "sync"
+
+type LogsMap struct {
+	// use sync.Mutex to avoid read/write
+	// access issues in multi-thread environments.
+	sync.Mutex
+	usedLogs map[string]int
+}
+
+// NewLogCoupling return an empty LogsMap struct ready to be used.
+func NewLogCoupling() *LogsMap {
+	return &LogsMap{
+		usedLogs: make(map[string]int),
+	}
+}
+
+// update add the logContent to the internal map
+// and set the occurrencty to 1 (if it has never been used before),
+// increment its values otherwise.
+func (lm *LogsMap) update(logContent string) {
+	lm.Lock()
+	_, ok := lm.usedLogs[logContent]
+	if !ok {
+		lm.usedLogs[logContent] = 1
+	} else {
+		lm.usedLogs[logContent]++
+	}
+	lm.Unlock()
+}
+
+// isDuplicated check if logContent is already present inside the internal map.
+// Return true in case logContent already exists, false otherwise.
+func (lm *LogsMap) isDuplicated(logContent string) bool {
+	lm.Lock()
+	_, ok := lm.usedLogs[logContent]
+	lm.Unlock()
+	return ok
+}
+
+// GgtOccurrence retrieve the number of occurrences logContent has been used.
+func (lm *LogsMap) getOccurrence(logContent string) int {
+	lm.Lock()
+	occurrence, ok := lm.usedLogs[logContent]
+	lm.Unlock()
+	if !ok {
+		return 0
+	}
+	return occurrence
+}