From b5c7ee330e8fe4ecce515fe30d416703861f2c3e Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Thu, 29 Sep 2022 22:00:44 +1000
Subject: [PATCH] fix: simplify Cid generation cache & usage

---
 node.go | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/node.go b/node.go
index 85f5b4f..b2f93de 100644
--- a/node.go
+++ b/node.go
@@ -393,19 +393,12 @@ func (n *ProtoNode) MarshalJSON() ([]byte, error) {
 // Cid returns the node's Cid, calculated according to its prefix
 // and raw data contents.
 func (n *ProtoNode) Cid() cid.Cid {
-	if n.encoded != nil && n.cached.Defined() {
-		return n.cached
-	}
-
-	c, err := n.CidBuilder().Sum(n.RawData())
-	if err != nil {
-		// programmer error
-		err = fmt.Errorf("invalid CID of length %d: %x: %v", len(n.RawData()), n.RawData(), err)
+	// re-encode if necessary and we'll get a new cached CID
+	if _, err := n.EncodeProtobuf(false); err != nil {
 		panic(err)
 	}
 
-	n.cached = c
-	return c
+	return n.cached
 }
 
 // String prints the node's Cid.
@@ -415,14 +408,7 @@ func (n *ProtoNode) String() string {
 
 // Multihash hashes the encoded data of this node.
 func (n *ProtoNode) Multihash() mh.Multihash {
-	// NOTE: EncodeProtobuf generates the hash and puts it in n.cached.
-	_, err := n.EncodeProtobuf(false)
-	if err != nil {
-		// Note: no possibility exists for an error to be returned through here
-		panic(err)
-	}
-
-	return n.cached.Hash()
+	return n.Cid().Hash()
 }
 
 // Links returns a copy of the node's links.