WIP

internal/core/block/block.go

@@ -121,6 +121,9 @@ type Encryption struct {
 type Block struct {
 	// Delta is the CRDT delta that is stored in the block.
 	Delta crdt.CRDT
+
+	Heads []cidlink.Link
+
 	// Links are the links to other blocks in the DAG.
 	Links []DAGLink
 	// Encryption contains the encryption information for the block's delta.
@@ -142,6 +145,18 @@ func (block *Block) Clone() *Block {
 	}
 }
 
+func (block *Block) Links2() []cidlink.Link {
+	result := make([]cidlink.Link, 0, len(block.Heads)+len(block.Links))
+
+	result = append(result, block.Heads...)
+
+	for _, link := range block.Links {
+		result = append(result, link.Link)
+	}
+
+	return result
+}
+
 // GetHeadLinks returns the CIDs of the previous blocks. There can be more than 1 with multiple heads.
 func (block *Block) GetHeadLinks() []cid.Cid {
 	var heads []cid.Cid
@@ -160,6 +175,7 @@ func (block *Block) IPLDSchemaBytes() []byte {
 	return []byte(`
 		type Block struct {
 			delta       CRDT
+			heads       [Link]
 			links       [DAGLink]
 			encryption  optional Link
 		}

net/sync_dag.go

@@ -72,9 +72,9 @@ func loadBlockLinks(ctx context.Context, lsys linking.LinkSystem, block *coreblo
 		cancel()
 	}
 
-	for _, lnk := range block.Links {
+	for _, lnk := range block.Links2() {
 		wg.Add(1)
-		go func(lnk coreblock.DAGLink) {
+		go func(lnk cidlink.Link) {
 			defer wg.Done()
 			if ctx.Err() != nil {
 				return