Use generics for maps and slices

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/smartystreets/goconvey v1.6.4
 	github.com/stretchr/testify v1.8.4
 	github.com/vektra/errors v0.0.0-20140903201135-c64d83aba85a
+	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb
 	golang.org/x/net v0.19.0
 	golang.org/x/time v0.5.0
 	google.golang.org/grpc v1.59.0
@@ -163,7 +164,6 @@ require (
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.24.0 // indirect
 	golang.org/x/crypto v0.16.0 // indirect
-	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb // indirect
 	golang.org/x/mod v0.14.0 // indirect
 	golang.org/x/oauth2 v0.14.0 // indirect
 	golang.org/x/sync v0.5.0 // indirect

pkg/apis/nfd/v1alpha1/expression.go

@@ -24,6 +24,7 @@ import (
 	"strconv"
 	"strings"
 
+	"golang.org/x/exp/maps"
 	"k8s.io/klog/v2"
 )
 
@@ -259,10 +260,7 @@ func (m *MatchExpression) MatchKeys(name string, keys map[string]Nil) (bool, err
 	if klogV := klog.V(3); klogV.Enabled() {
 		klogV.InfoS("matched keys", "matchResult", matched, "matchKey", name, "matchOp", m.Op)
 	} else if klogV := klog.V(4); klogV.Enabled() {
-		k := make([]string, 0, len(keys))
-		for n := range keys {
-			k = append(k, n)
-		}
+		k := maps.Keys(keys)
 		sort.Strings(k)
 		klogV.InfoS("matched keys", "matchResult", matched, "matchKey", name, "matchOp", m.Op, "inputKeys", k)
 	}

pkg/apis/nfd/v1alpha1/feature.go

@@ -16,6 +16,8 @@ limitations under the License.
 
 package v1alpha1
 
+import "maps"
+
 // NewNodeFeatureSpec creates a new emprty instance of NodeFeatureSpec type,
 // initializing all fields to proper empty values.
 func NewNodeFeatureSpec() *NodeFeatureSpec {
@@ -75,9 +77,7 @@ func (f *Features) InsertAttributeFeatures(domain, feature string, values map[st
 		return
 	}
 
-	for k, v := range values {
-		f.Attributes[key].Elements[k] = v
-	}
+	maps.Copy(f.Attributes[key].Elements, values)
 }
 
 // Exists returns a non-empty string if a feature exists. The return value is
@@ -103,9 +103,7 @@ func (in *NodeFeatureSpec) MergeInto(out *NodeFeatureSpec) {
 		if out.Labels == nil {
 			out.Labels = make(map[string]string, len(in.Labels))
 		}
-		for key, val := range in.Labels {
-			out.Labels[key] = val
-		}
+		maps.Copy(out.Labels, in.Labels)
 	}
 }
 
@@ -151,9 +149,7 @@ func (in *FlagFeatureSet) MergeInto(out *FlagFeatureSet) {
 		if out.Elements == nil {
 			out.Elements = make(map[string]Nil, len(in.Elements))
 		}
-		for key, val := range in.Elements {
-			out.Elements[key] = val
-		}
+		maps.Copy(out.Elements, in.Elements)
 	}
 }
 
@@ -163,9 +159,7 @@ func (in *AttributeFeatureSet) MergeInto(out *AttributeFeatureSet) {
 		if out.Elements == nil {
 			out.Elements = make(map[string]string, len(in.Elements))
 		}
-		for key, val := range in.Elements {
-			out.Elements[key] = val
-		}
+		maps.Copy(out.Elements, in.Elements)
 	}
 }
 

pkg/apis/nfd/v1alpha1/rule.go

@@ -19,6 +19,8 @@ package v1alpha1
 import (
 	"bytes"
 	"fmt"
+	"maps"
+	"slices"
 	"strings"
 	"text/template"
 
@@ -40,7 +42,6 @@ type RuleOutput struct {
 
 // Execute the rule against a set of input features.
 func (r *Rule) Execute(features *Features) (RuleOutput, error) {
-	extendedResources := make(map[string]string)
 	labels := make(map[string]string)
 	vars := make(map[string]string)
 
@@ -92,18 +93,16 @@ func (r *Rule) Execute(features *Features) (RuleOutput, error) {
 		}
 	}
 
-	for k, v := range r.ExtendedResources {
-		extendedResources[k] = v
-	}
+	maps.Copy(labels, r.Labels)
+	maps.Copy(vars, r.Vars)
 
-	for k, v := range r.Labels {
-		labels[k] = v
+	ret := RuleOutput{
+		Labels:            labels,
+		Vars:              vars,
+		Annotations:       maps.Clone(r.Annotations),
+		ExtendedResources: maps.Clone(r.ExtendedResources),
+		Taints:            slices.Clone(r.Taints),
 	}
-	for k, v := range r.Vars {
-		vars[k] = v
-	}
-
-	ret := RuleOutput{ExtendedResources: extendedResources, Labels: labels, Vars: vars, Taints: r.Taints, Annotations: r.Annotations}
 	klog.V(2).InfoS("rule matched", "ruleName", r.Name, "ruleOutput", utils.DelayedDumper(ret))
 	return ret, nil
 }

pkg/nfd-master/nfd-master.go

@@ -20,6 +20,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
+	"maps"
 	"net"
 	"os"
 	"path"
@@ -477,11 +478,9 @@ func (m *nfdMaster) prune() error {
 		if err != nil {
 			return err
 		}
-		for a := range node.Annotations {
-			if strings.HasPrefix(a, m.instanceAnnotation(nfdv1alpha1.AnnotationNs)) {
-				delete(node.Annotations, a)
-			}
-		}
+		maps.DeleteFunc(node.Annotations, func(k, v string) bool {
+			return strings.HasPrefix(k, m.instanceAnnotation(nfdv1alpha1.AnnotationNs))
+		})
 		err = m.apihelper.UpdateNode(cli, node)
 		if err != nil {
 			return fmt.Errorf("failed to prune annotations from node %q: %v", node.Name, err)
@@ -812,18 +811,14 @@ func (m *nfdMaster) refreshNodeFeatures(cli *kubernetes.Clientset, nodeName stri
 	crLabels, crAnnotations, crExtendedResources, crTaints := m.processNodeFeatureRule(nodeName, features)
 
 	// Mix in CR-originated labels
-	for k, v := range crLabels {
-		labels[k] = v
-	}
+	maps.Copy(labels, crLabels)
 
 	// Remove labels which are intended to be extended resources via
 	// -resource-labels or their NS is not whitelisted
 	labels, extendedResources := m.filterFeatureLabels(labels, features)
 
 	// Mix in CR-originated extended resources with -resource-labels
-	for k, v := range crExtendedResources {
-		extendedResources[k] = v
-	}
+	maps.Copy(extendedResources, crExtendedResources)
 	extendedResources = m.filterExtendedResources(features, extendedResources)
 
 	// Annotations
@@ -991,15 +986,9 @@ func (m *nfdMaster) processNodeFeatureRule(nodeName string, features *nfdv1alpha
 				e = addNsToMapKeys(ruleOut.ExtendedResources, nfdv1alpha1.ExtendedResourceNs)
 				a = addNsToMapKeys(ruleOut.Annotations, nfdv1alpha1.FeatureAnnotationNs)
 			}
-			for k, v := range l {
-				labels[k] = v
-			}
-			for k, v := range e {
-				extendedResources[k] = v
-			}
-			for k, v := range a {
-				annotations[k] = v
-			}
+			maps.Copy(labels, l)
+			maps.Copy(extendedResources, e)
+			maps.Copy(annotations, a)
 
 			// Feed back rule output to features map for subsequent rules to match
 			features.InsertAttributeFeatures(nfdv1alpha1.RuleBackrefDomain, nfdv1alpha1.RuleBackrefFeature, ruleOut.Labels)
@@ -1061,9 +1050,7 @@ func (m *nfdMaster) updateNodeObject(cli *kubernetes.Clientset, nodeName string,
 		}
 		sort.Strings(annotationKeys)
 		annotations[m.instanceAnnotation(nfdv1alpha1.FeatureAnnotationsTrackingAnnotation)] = strings.Join(annotationKeys, ",")
-		for k, v := range featureAnnotations {
-			annotations[k] = v
-		}
+		maps.Copy(annotations, featureAnnotations)
 	}
 
 	// Create JSON patches for changes in labels and annotations

pkg/nfd-worker/nfd-worker.go

@@ -28,6 +28,7 @@ import (
 	"strings"
 	"time"
 
+	"golang.org/x/exp/maps"
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -415,10 +416,7 @@ func (w *nfdWorker) configureCore(c coreConfig) error {
 		}
 	}
 
-	w.featureSources = make([]source.FeatureSource, 0, len(featureSources))
-	for _, s := range featureSources {
-		w.featureSources = append(w.featureSources, s)
-	}
+	w.featureSources = maps.Values(featureSources)
 
 	sort.Slice(w.featureSources, func(i, j int) bool { return w.featureSources[i].Name() < w.featureSources[j].Name() })
 
@@ -450,10 +448,7 @@ func (w *nfdWorker) configureCore(c coreConfig) error {
 		}
 	}
 
-	w.labelSources = make([]source.LabelSource, 0, len(labelSources))
-	for _, s := range labelSources {
-		w.labelSources = append(w.labelSources, s)
-	}
+	w.labelSources = maps.Values(labelSources)
 
 	sort.Slice(w.labelSources, func(i, j int) bool {
 		iP, jP := w.labelSources[i].Priority(), w.labelSources[j].Priority()
@@ -560,9 +555,7 @@ func createFeatureLabels(sources []source.LabelSource, labelWhiteList regexp.Reg
 			continue
 		}
 
-		for name, value := range labelsFromSource {
-			labels[name] = value
-		}
+		maps.Copy(labels, labelsFromSource)
 	}
 	if klogV := klog.V(1); klogV.Enabled() {
 		klogV.InfoS("feature discovery completed", "labels", utils.DelayedDumper(labels))

pkg/utils/flags.go

@@ -24,6 +24,8 @@ import (
 	"sort"
 	"strings"
 	"time"
+
+	"golang.org/x/exp/maps"
 )
 
 // RegexpVal is a wrapper for regexp command line flags
@@ -77,10 +79,7 @@ func (a *StringSetVal) String() string {
 	if *a == nil {
 		return ""
 	}
-	vals := make([]string, 0, len(*a))
-	for val := range *a {
-		vals = append(vals, val)
-	}
+	vals := maps.Keys(*a)
 	sort.Strings(vals)
 	return strings.Join(vals, ",")
 }

pkg/utils/memory_resources.go

@@ -18,6 +18,7 @@ package utils
 
 import (
 	"fmt"
+	"maps"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -75,9 +76,7 @@ func GetNumaMemoryResources() (NumaMemoryResources, error) {
 				return nil, err
 			}
 		}
-		for n, s := range hugepageBytes {
-			info[n] = s
-		}
+		maps.Copy(info, hugepageBytes)
 
 		memoryResources[nodeID] = info
 	}

source/pci/pci.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"strings"
 
+	"golang.org/x/exp/maps"
 	"k8s.io/klog/v2"
 
 	nfdv1alpha1 "sigs.k8s.io/node-feature-discovery/pkg/apis/nfd/v1alpha1"
@@ -102,11 +103,7 @@ func (s *pciSource) GetLabels() (source.FeatureLabels, error) {
 		}
 	}
 	if len(configLabelFields) > 0 {
-		keys := []string{}
-		for key := range configLabelFields {
-			keys = append(keys, key)
-		}
-		klog.InfoS("ignoring invalid fields in deviceLabelFields", "invalidFieldNames", keys)
+		klog.InfoS("ignoring invalid fields in deviceLabelFields", "invalidFieldNames", maps.Keys(configLabelFields))
 	}
 	if len(deviceLabelFields) == 0 {
 		deviceLabelFields = []string{"class", "vendor"}

source/usb/usb.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"strings"
 
+	"golang.org/x/exp/maps"
 	"k8s.io/klog/v2"
 
 	nfdv1alpha1 "sigs.k8s.io/node-feature-discovery/pkg/apis/nfd/v1alpha1"
@@ -105,11 +106,7 @@ func (s *usbSource) GetLabels() (source.FeatureLabels, error) {
 		}
 	}
 	if len(configLabelFields) > 0 {
-		keys := []string{}
-		for key := range configLabelFields {
-			keys = append(keys, key)
-		}
-		klog.InfoS("ignoring invalid fields in deviceLabelFields", "invalidFieldNames", keys)
+		klog.InfoS("ignoring invalid fields in deviceLabelFields", "invalidFieldNames", maps.Keys(configLabelFields))
 	}
 	if len(deviceLabelFields) == 0 {
 		deviceLabelFields = defaultDeviceLabelFields()