Implemented user server state aka route list

internal/server/user/state.go

@@ -0,0 +1,37 @@
+package user
+
+import (
+	"sync"
+
+	"github.com/BBVA/kapow/internal/server/model"
+)
+
+type safeRouteList struct {
+	rs []model.Route
+	m  sync.RWMutex
+}
+
+var Routes = New()
+
+func New() safeRouteList {
+	return safeRouteList{}
+}
+
+func (srl *safeRouteList) Append(r model.Route) {
+	srl.m.Lock()
+	srl.rs = append(srl.rs, r)
+	srl.m.Unlock()
+}
+
+func (srl *safeRouteList) Snapshot() []model.Route {
+	srl.m.RLock()
+	defer srl.m.RUnlock()
+
+	if srl.rs == nil {
+		return nil
+	} else {
+		rs := make([]model.Route, len(srl.rs))
+		copy(rs, srl.rs)
+		return rs
+	}
+}