process: Use registry collector for V1 data (#1814)

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

internal/pdh/registry/collector.go

@@ -0,0 +1,178 @@
+package registry
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	"github.com/prometheus-community/windows_exporter/internal/mi"
+	"github.com/prometheus-community/windows_exporter/internal/pdh"
+)
+
+type Collector struct {
+	object string
+	query  string
+
+	counters       map[string]Counter
+	nameIndexValue int
+}
+
+type Counter struct {
+	Name      string
+	Desc      string
+	Instances map[string]uint32
+	Type      uint32
+	Frequency float64
+
+	FieldIndexValue       int
+	FieldIndexSecondValue int
+}
+
+func NewCollector[T any](object string, _ []string) (*Collector, error) {
+	collector := &Collector{
+		object:         object,
+		query:          MapCounterToIndex(object),
+		nameIndexValue: -1,
+		counters:       make(map[string]Counter),
+	}
+
+	var values [0]T
+	valueType := reflect.TypeOf(values).Elem()
+
+	if f, ok := valueType.FieldByName("Name"); ok {
+		if f.Type.Kind() == reflect.String {
+			collector.nameIndexValue = f.Index[0]
+		}
+	}
+
+	for _, f := range reflect.VisibleFields(valueType) {
+		counterName, ok := f.Tag.Lookup("perfdata")
+		if !ok {
+			continue
+		}
+
+		var counter Counter
+		if counter, ok = collector.counters[counterName]; !ok {
+			counter = Counter{
+				Name:                  counterName,
+				FieldIndexSecondValue: -1,
+				FieldIndexValue:       -1,
+			}
+		}
+
+		if strings.HasSuffix(counterName, ",secondvalue") {
+			counterName = strings.TrimSuffix(counterName, ",secondvalue")
+
+			counter.FieldIndexSecondValue = f.Index[0]
+		} else {
+			counter.FieldIndexValue = f.Index[0]
+		}
+
+		collector.counters[counterName] = counter
+	}
+
+	var collectValues []T
+
+	if err := collector.Collect(&collectValues); err != nil {
+		return nil, fmt.Errorf("failed to collect initial data: %w", err)
+	}
+
+	return collector, nil
+}
+
+func (c *Collector) Describe() map[string]string {
+	return map[string]string{}
+}
+
+func (c *Collector) Collect(data any) error {
+	dv := reflect.ValueOf(data)
+	if dv.Kind() != reflect.Ptr || dv.IsNil() {
+		return mi.ErrInvalidEntityType
+	}
+
+	dv = dv.Elem()
+
+	elemType := dv.Type().Elem()
+	elemValue := reflect.ValueOf(reflect.New(elemType).Interface()).Elem()
+
+	if dv.Kind() != reflect.Slice || elemType.Kind() != reflect.Struct {
+		return mi.ErrInvalidEntityType
+	}
+
+	perfObjects, err := QueryPerformanceData(c.query, c.object)
+	if err != nil {
+		return fmt.Errorf("QueryPerformanceData: %w", err)
+	}
+
+	if len(perfObjects) == 0 || perfObjects[0] == nil || len(perfObjects[0].Instances) == 0 {
+		return nil
+	}
+
+	if dv.Len() != 0 {
+		dv.Set(reflect.MakeSlice(dv.Type(), 0, len(perfObjects[0].Instances)))
+	}
+
+	dv.Clear()
+
+	for _, perfObject := range perfObjects {
+		if perfObject.Name != c.object {
+			continue
+		}
+
+		for _, perfInstance := range perfObject.Instances {
+			instanceName := perfInstance.Name
+			if strings.HasSuffix(instanceName, "_Total") {
+				continue
+			}
+
+			if instanceName == "" || instanceName == "*" {
+				instanceName = pdh.InstanceEmpty
+			}
+
+			if c.nameIndexValue != -1 {
+				elemValue.Field(c.nameIndexValue).SetString(instanceName)
+			}
+
+			dv.Set(reflect.Append(dv, elemValue))
+			index := dv.Len() - 1
+
+			for _, perfCounter := range perfInstance.Counters {
+				if perfCounter.Def.IsBaseValue && !perfCounter.Def.IsNanosecondCounter {
+					continue
+				}
+
+				counter, ok := c.counters[perfCounter.Def.Name]
+				if !ok {
+					continue
+				}
+
+				switch perfCounter.Def.CounterType {
+				case pdh.PERF_ELAPSED_TIME:
+					dv.Index(index).
+						Field(counter.FieldIndexValue).
+						SetFloat(float64((perfCounter.Value - pdh.WindowsEpoch) / perfObject.Frequency))
+				case pdh.PERF_100NSEC_TIMER, pdh.PERF_PRECISION_100NS_TIMER:
+					dv.Index(index).
+						Field(counter.FieldIndexValue).
+						SetFloat(float64(perfCounter.Value) * pdh.TicksToSecondScaleFactor)
+				default:
+					if counter.FieldIndexSecondValue != -1 {
+						dv.Index(index).
+							Field(counter.FieldIndexSecondValue).
+							SetFloat(float64(perfCounter.SecondValue))
+					}
+
+					if counter.FieldIndexValue != -1 {
+						dv.Index(index).
+							Field(counter.FieldIndexValue).
+							SetFloat(float64(perfCounter.Value))
+					}
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (c *Collector) Close() {}