Refactor collectors

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

pkg/perflib/utils.go

@@ -0,0 +1,22 @@
+package perflib
+
+import (
+	"strconv"
+)
+
+func MapCounterToIndex(name string) string {
+	return strconv.Itoa(int(CounterNameTable.LookupIndex(name)))
+}
+
+func GetPerflibSnapshot(objNames string) (map[string]*PerfObject, error) {
+	objects, err := QueryPerformanceData(objNames)
+	if err != nil {
+		return nil, err
+	}
+
+	indexed := make(map[string]*PerfObject)
+	for _, obj := range objects {
+		indexed[obj.Name] = obj
+	}
+	return indexed, nil
+}