From 6764ef2f6cf16bcf2e91766afc5d911ed3ea7e2e Mon Sep 17 00:00:00 2001
From: bianyuanop <chen.me.nan@gmail.com>
Date: Fri, 19 Jan 2024 17:05:46 -0500
Subject: [PATCH] preallocate memory for merkle array and consumebytes flag

---
 chain/block.go          | 5 +++--
 hypersdk.code-workspace | 8 ++++++++
 utils/utils.go          | 6 +++---
 3 files changed, 14 insertions(+), 5 deletions(-)
 create mode 100644 hypersdk.code-workspace

diff --git a/chain/block.go b/chain/block.go
index 2a10ae17bb..beaf74ce10 100644
--- a/chain/block.go
+++ b/chain/block.go
@@ -293,7 +293,7 @@ func (b *StatelessBlock) initializeBuilt(
 	}
 
 	// transaction hash generation
-	var merkleItems [][]byte
+	merkleItems := make([][]byte, 0, len(b.Txs)+len(b.results))
 	for _, tx := range b.Txs {
 		merkleItems = append(merkleItems, tx.Bytes())
 	}
@@ -301,7 +301,8 @@ func (b *StatelessBlock) initializeBuilt(
 		merkleItems = append(merkleItems, result.Output)
 	}
 
-	root, _, err := utils.GenerateMerkleRoot(ctx, b.vm.Tracer(), merkleItems)
+	// consume bytes to avoid extra copying
+	root, _, err := utils.GenerateMerkleRoot(ctx, b.vm.Tracer(), merkleItems, true)
 	if err != nil {
 		return err
 	}
diff --git a/hypersdk.code-workspace b/hypersdk.code-workspace
new file mode 100644
index 0000000000..876a1499c0
--- /dev/null
+++ b/hypersdk.code-workspace
@@ -0,0 +1,8 @@
+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {}
+}
\ No newline at end of file
diff --git a/utils/utils.go b/utils/utils.go
index 86384e1034..fac2f0bacc 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -125,8 +125,8 @@ func LoadBytes(filename string, expectedSize int) ([]byte, error) {
 
 // Generate merkle root for a set of items
 // this function does not take ownership of given bytes array
-func GenerateMerkleRoot(ctx context.Context, tracer trace.Tracer, merkleItems [][]byte) ([]byte, merkledb.MerkleDB, error) {
-	var batchOps []database.BatchOp
+func GenerateMerkleRoot(ctx context.Context, tracer trace.Tracer, merkleItems [][]byte, consumeBytes bool) ([]byte, merkledb.MerkleDB, error) {
+	batchOps := make([]database.BatchOp, 0, len(merkleItems))
 
 	for _, item := range merkleItems {
 		key := ToID(item)
@@ -148,7 +148,7 @@ func GenerateMerkleRoot(ctx context.Context, tracer trace.Tracer, merkleItems []
 		return nil, nil, err
 	}
 
-	view, err := db.NewView(ctx, merkledb.ViewChanges{BatchOps: batchOps})
+	view, err := db.NewView(ctx, merkledb.ViewChanges{BatchOps: batchOps, ConsumeBytes: consumeBytes})
 	if err != nil {
 		return nil, nil, err
 	}