Refactor collectors

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

pkg/collector/collector.go

@@ -0,0 +1,105 @@
+//go:build windows
+
+package collector
+
+import (
+	"slices"
+	"strings"
+
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/go-kit/log"
+	"github.com/prometheus-community/windows_exporter/pkg/perflib"
+	"github.com/prometheus-community/windows_exporter/pkg/types"
+)
+
+type Collectors struct {
+	logger log.Logger
+
+	collectors       map[string]types.Collector
+	perfCounterQuery string
+}
+
+// NewWithFlags To be called by the exporter for collector initialization before running kingpin.Parse
+func NewWithFlags(app *kingpin.Application) Collectors {
+	collectors := map[string]types.Collector{}
+
+	for name, builder := range Map {
+		collectors[name] = builder(app)
+	}
+
+	return New(collectors)
+}
+
+// New To be called by the external libraries for collector initialization without running kingpin.Parse
+func New(collectors map[string]types.Collector) Collectors {
+	return Collectors{
+		collectors: collectors,
+	}
+}
+
+func (c *Collectors) SetLogger(logger log.Logger) {
+	c.logger = logger
+
+	for _, collector := range c.collectors {
+		collector.SetLogger(logger)
+	}
+}
+
+func (c *Collectors) SetPerfCounterQuery() error {
+	var (
+		err error
+
+		perfCounterDependencies []string
+		perfCounterNames        []string
+		perfIndicies            []string
+	)
+
+	for _, collector := range c.collectors {
+		perfCounterNames, err = collector.GetPerfCounter()
+		if err != nil {
+			return err
+		}
+
+		perfIndicies = make([]string, 0, len(perfCounterNames))
+		for _, cn := range perfCounterNames {
+			perfIndicies = append(perfIndicies, perflib.MapCounterToIndex(cn))
+		}
+
+		perfCounterDependencies = append(perfCounterDependencies, strings.Join(perfIndicies, " "))
+	}
+
+	c.perfCounterQuery = strings.Join(perfCounterDependencies, " ")
+
+	return nil
+}
+
+// Enable removes all collectors that not enabledCollectors
+func (c *Collectors) Enable(enabledCollectors []string) {
+	for name := range c.collectors {
+		if !slices.Contains(enabledCollectors, name) {
+			delete(c.collectors, name)
+		}
+	}
+}
+
+// Build To be called by the exporter for collector initialization
+func (c *Collectors) Build() error {
+	var err error
+	for _, collector := range c.collectors {
+		if err = collector.Build(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// PrepareScrapeContext creates a ScrapeContext to be used during a single scrape
+func (c *Collectors) PrepareScrapeContext() (*types.ScrapeContext, error) {
+	objs, err := perflib.GetPerflibSnapshot(c.perfCounterQuery)
+	if err != nil {
+		return nil, err
+	}
+
+	return &types.ScrapeContext{PerfObjects: objs}, nil
+}