RefRoot: add some methods

We want to add another type of root, so start the virtualization
process.

Author: mhagger

sizes/graph.go

@@ -38,11 +38,11 @@ func ScanRepositoryUsingGraph(
 
 		errChan <- func() error {
 			for _, refRoot := range refRoots {
-				if !refRoot.Walk {
+				if !refRoot.Walk() {
 					continue
 				}
 
-				if err := objIter.AddRoot(refRoot.OID); err != nil {
+				if err := objIter.AddRoot(refRoot.OID()); err != nil {
 					return err
 				}
 			}
@@ -258,7 +258,7 @@ func ScanRepositoryUsingGraph(
 	progressMeter.Start("Processing references: %d")
 	for _, refRoot := range refRoots {
 		progressMeter.Inc()
-		graph.RegisterReference(refRoot.Reference, refRoot.Walk, refRoot.Groups)
+		graph.RegisterReference(refRoot.Reference(), refRoot.Walk(), refRoot.Groups())
 	}
 	progressMeter.Done()
 

sizes/grouper.go

@@ -45,11 +45,16 @@ type RefGrouper interface {
 }
 
 type RefRoot struct {
-	git.Reference
-	Walk   bool
-	Groups []RefGroupSymbol
+	ref    git.Reference
+	walk   bool
+	groups []RefGroupSymbol
 }
 
+func (rr RefRoot) OID() git.OID             { return rr.ref.OID }
+func (rr RefRoot) Reference() git.Reference { return rr.ref }
+func (rr RefRoot) Walk() bool               { return rr.walk }
+func (rr RefRoot) Groups() []RefGroupSymbol { return rr.groups }
+
 func CollectReferences(
 	ctx context.Context, repo *git.Repository, rg RefGrouper,
 ) ([]RefRoot, error) {
@@ -73,9 +78,9 @@ func CollectReferences(
 		refsSeen = append(
 			refsSeen,
 			RefRoot{
-				Reference: ref,
-				Walk:      walk,
-				Groups:    groups,
+				ref:    ref,
+				walk:   walk,
+				groups: groups,
 			},
 		)
 	}