Merge pull request #2323 from prometheus/beorn7/retrieval

Retrieval: Avoid copying Target

retrieval/targetmanager.go

@@ -132,16 +132,16 @@ func (tm *TargetManager) reload() {
 }
 
 // Targets returns the targets currently being scraped bucketed by their job name.
-func (tm *TargetManager) Targets() []Target {
+func (tm *TargetManager) Targets() []*Target {
 	tm.mtx.RLock()
 	defer tm.mtx.RUnlock()
 
-	targets := []Target{}
+	targets := []*Target{}
 	for _, ps := range tm.targetSets {
 		ps.sp.mtx.RLock()
 
 		for _, t := range ps.sp.targets {
-			targets = append(targets, *t)
+			targets = append(targets, t)
 		}
 
 		ps.sp.mtx.RUnlock()

web/api/v1/api.go

@@ -68,7 +68,7 @@ func (e *apiError) Error() string {
 }
 
 type targetRetriever interface {
-	Targets() []retrieval.Target
+	Targets() []*retrieval.Target
 }
 
 type response struct {

web/api/v1/api_test.go

@@ -33,9 +33,9 @@ import (
 	"github.com/prometheus/prometheus/retrieval"
 )
 
-type targetRetrieverFunc func() []retrieval.Target
+type targetRetrieverFunc func() []*retrieval.Target
 
-func (f targetRetrieverFunc) Targets() []retrieval.Target {
+func (f targetRetrieverFunc) Targets() []*retrieval.Target {
 	return f()
 }
 
@@ -57,9 +57,9 @@ func TestEndpoints(t *testing.T) {
 
 	now := model.Now()
 
-	tr := targetRetrieverFunc(func() []retrieval.Target {
-		return []retrieval.Target{
-			*retrieval.NewTarget(
+	tr := targetRetrieverFunc(func() []*retrieval.Target {
+		return []*retrieval.Target{
+			retrieval.NewTarget(
 				model.LabelSet{
 					model.SchemeLabel:      "http",
 					model.AddressLabel:     "example.com:8080",

web/web.go

@@ -373,14 +373,14 @@ func (h *Handler) rules(w http.ResponseWriter, r *http.Request) {
 
 func (h *Handler) targets(w http.ResponseWriter, r *http.Request) {
 	// Bucket targets by job label
-	tps := map[string][]retrieval.Target{}
+	tps := map[string][]*retrieval.Target{}
 	for _, t := range h.targetManager.Targets() {
 		job := string(t.Labels()[model.JobLabel])
 		tps[job] = append(tps[job], t)
 	}
 
 	h.executeTemplate(w, "targets.html", struct {
-		TargetPools map[string][]retrieval.Target
+		TargetPools map[string][]*retrieval.Target
 	}{
 		TargetPools: tps,
 	})