Store/Search: Explore a general interface to extract summary data from a blob (#55598)

pkg/services/store/object/reference.go

@@ -0,0 +1,51 @@
+package object
+
+import (
+	"fmt"
+	"sort"
+)
+
+// A reference accumulator can combine
+type ReferenceAccumulator interface {
+	// Add references as we find them
+	Add(kind string, subtype string, uid string)
+
+	// Returns the set of distinct references in a sorted order
+	Get() []*ExternalReference
+}
+
+func NewReferenceAccumulator() ReferenceAccumulator {
+	return &referenceAccumulator{
+		refs: make(map[string]*ExternalReference),
+	}
+}
+
+type referenceAccumulator struct {
+	refs map[string]*ExternalReference
+}
+
+func (x *referenceAccumulator) Add(kind string, sub string, uid string) {
+	key := fmt.Sprintf("%s/%s/%s", kind, sub, uid)
+	_, ok := x.refs[key]
+	if !ok {
+		x.refs[key] = &ExternalReference{
+			Kind: kind,
+			Type: sub,
+			UID:  uid,
+		}
+	}
+}
+
+func (x *referenceAccumulator) Get() []*ExternalReference {
+	keys := make([]string, 0, len(x.refs))
+	for k := range x.refs {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	refs := make([]*ExternalReference, len(keys))
+	for i, key := range keys {
+		refs[i] = x.refs[key]
+	}
+	return refs
+}