trie/trienode: avoid unnecessary copy (#30019)

* avoid unnecessary copy

* delete the never used function ProofList

* eth/protocols/snap, trie/trienode: polish the code

---------

Co-authored-by: Gary Rong <garyrong0905@gmail.com>

eth/protocols/snap/handler.go

@@ -332,11 +332,7 @@ func ServiceGetAccountRangeQuery(chain *core.BlockChain, req *GetAccountRangePac
 			return nil, nil
 		}
 	}
-	var proofs [][]byte
+	return accounts, proof.List()
-	for _, blob := range proof.List() {
-		proofs = append(proofs, blob)
-	}
-	return accounts, proofs
 }
 
 func ServiceGetStorageRangesQuery(chain *core.BlockChain, req *GetStorageRangesPacket) ([][]*StorageData, [][]byte) {
@@ -438,9 +434,7 @@ func ServiceGetStorageRangesQuery(chain *core.BlockChain, req *GetStorageRangesP
 					return nil, nil
 				}
 			}
-			for _, blob := range proof.List() {
+			proofs = append(proofs, proof.List()...)
-				proofs = append(proofs, blob)
-			}
 			// Proof terminates the reply as proofs are only added if a node
 			// refuses to serve more data (exception when a contract fetch is
 			// finishing, but that's that).

eth/protocols/snap/sync_test.go

@@ -286,10 +286,7 @@ func createAccountRequestResponse(t *testPeer, root common.Hash, origin common.H
 			t.logger.Error("Could not prove last item", "error", err)
 		}
 	}
-	for _, blob := range proof.List() {
+	return keys, vals, proof.List()
-		proofs = append(proofs, blob)
-	}
-	return keys, vals, proofs
 }
 
 // defaultStorageRequestHandler is a well-behaving storage request handler
@@ -371,9 +368,7 @@ func createStorageRequestResponse(t *testPeer, root common.Hash, accounts []comm
 					t.logger.Error("Could not prove last item", "error", err)
 				}
 			}
-			for _, blob := range proof.List() {
+			proofs = append(proofs, proof.List()...)
-				proofs = append(proofs, blob)
-			}
 			break
 		}
 	}
@@ -430,9 +425,7 @@ func createStorageRequestResponseAlwaysProve(t *testPeer, root common.Hash, acco
 					t.logger.Error("Could not prove last item", "error", err)
 				}
 			}
-			for _, blob := range proof.List() {
+			proofs = append(proofs, proof.List()...)
-				proofs = append(proofs, blob)
-			}
 			break
 		}
 	}
@@ -586,7 +579,6 @@ func testSyncBloatedProof(t *testing.T, scheme string) {
 
 	source.accountRequestHandler = func(t *testPeer, requestId uint64, root common.Hash, origin common.Hash, limit common.Hash, cap uint64) error {
 		var (
-			proofs [][]byte
 			keys []common.Hash
 			vals [][]byte
 		)
@@ -618,10 +610,7 @@ func testSyncBloatedProof(t *testing.T, scheme string) {
 			keys = append(keys[:1], keys[2:]...)
 			vals = append(vals[:1], vals[2:]...)
 		}
-		for _, blob := range proof.List() {
+		if err := t.remote.OnAccounts(t, requestId, keys, vals, proof.List()); err != nil {
-			proofs = append(proofs, blob)
-		}
-		if err := t.remote.OnAccounts(t, requestId, keys, vals, proofs); err != nil {
 			t.logger.Info("remote error on delivery (as expected)", "error", err)
 			t.term()
 			// This is actually correct, signal to exit the test successfully

trie/trienode/proof.go

@@ -102,14 +102,14 @@ func (db *ProofSet) DataSize() int {
 	return db.dataSize
 }
 
-// List converts the node set to a ProofList
+// List converts the node set to a slice of bytes.
-func (db *ProofSet) List() ProofList {
+func (db *ProofSet) List() [][]byte {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	var values ProofList
+	values := make([][]byte, len(db.order))
-	for _, key := range db.order {
+	for i, key := range db.order {
-		values = append(values, db.nodes[key])
+		values[i] = db.nodes[key]
 	}
 	return values
 }