From 74a82894df9bdef19d321611255b7923f9f25aff Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sun, 2 Apr 2023 18:36:11 -0600
Subject: btrfsutil: GraphNode: Have .MinItem and .MaxItem work on interior
 nodes too

---
 lib/btrfsutil/graph.go | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

(limited to 'lib/btrfsutil/graph.go')

diff --git a/lib/btrfsutil/graph.go b/lib/btrfsutil/graph.go
index 090ccf4..fe7fe70 100644
--- a/lib/btrfsutil/graph.go
+++ b/lib/btrfsutil/graph.go
@@ -23,34 +23,52 @@ import (
 )
 
 type GraphNode struct {
+	Addr       btrfsvol.LogicalAddr
 	Level      uint8
 	Generation btrfsprim.Generation
 	Owner      btrfsprim.ObjID
 	Items      []btrfsprim.Key
 }
 
-func (n GraphNode) MinItem() btrfsprim.Key {
-	if len(n.Items) == 0 {
+func (n GraphNode) NumItems(g Graph) int {
+	switch n.Level {
+	case 0:
+		return len(n.Items)
+	default:
+		return len(g.EdgesFrom[n.Addr])
+	}
+}
+
+func (n GraphNode) MinItem(g Graph) btrfsprim.Key {
+	if n.NumItems(g) == 0 {
 		return btrfsprim.Key{}
 	}
-	return n.Items[0]
+	switch n.Level {
+	case 0:
+		return n.Items[0]
+	default:
+		return g.EdgesFrom[n.Addr][0].ToKey
+	}
 }
 
-func (n GraphNode) MaxItem() btrfsprim.Key {
-	if len(n.Items) == 0 {
+func (n GraphNode) MaxItem(g Graph) btrfsprim.Key {
+	if n.NumItems(g) == 0 {
 		return btrfsprim.Key{}
 	}
-	return n.Items[len(n.Items)-1]
+	switch n.Level {
+	case 0:
+		return n.Items[len(n.Items)-1]
+	default:
+		return g.EdgesFrom[n.Addr][len(g.EdgesFrom[n.Addr])-1].ToKey
+	}
 }
 
 func (n GraphNode) String() string {
 	if reflect.ValueOf(n).IsZero() {
 		return "{}"
 	}
-	return fmt.Sprintf(`{lvl:%v, gen:%v, tree:%v, cnt:%v, min:(%v,%v,%v), max:(%v,%v,%v)}`,
-		n.Level, n.Generation, n.Owner, len(n.Items),
-		n.MinItem().ObjectID, n.MinItem().ItemType, n.MinItem().Offset,
-		n.MaxItem().ObjectID, n.MaxItem().ItemType, n.MaxItem().Offset)
+	return fmt.Sprintf(`{lvl:%v, gen:%v, tree:%v, cnt:%v}`,
+		n.Level, n.Generation, n.Owner, len(n.Items))
 }
 
 type GraphEdge struct {
@@ -150,6 +168,7 @@ func NewGraph(ctx context.Context, sb btrfstree.Superblock) Graph {
 
 func (g Graph) InsertNode(node *btrfstree.Node) {
 	nodeData := GraphNode{
+		Addr:       node.Head.Addr,
 		Level:      node.Head.Level,
 		Generation: node.Head.Generation,
 		Owner:      node.Head.Owner,
-- 
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