core, rpc: speed up tests ethereum#28461 (#1008)

Author: gzliudan

core/state/statedb_test.go

@@ -366,23 +366,21 @@ func (test *snapshotTest) run() bool {
 		state, _     = New(types.EmptyRootHash, NewDatabase(db))
 		snapshotRevs = make([]int, len(test.snapshots))
 		sindex       = 0
+		checkstates  = make([]*StateDB, len(test.snapshots))
 	)
 	for i, action := range test.actions {
 		if len(test.snapshots) > sindex && i == test.snapshots[sindex] {
 			snapshotRevs[sindex] = state.Snapshot()
+			checkstates[sindex] = state.Copy()
 			sindex++
 		}
 		action.fn(action, state)
 	}
 	// Revert all snapshots in reverse order. Each revert must yield a state
 	// that is equivalent to fresh state with all actions up the snapshot applied.
 	for sindex--; sindex >= 0; sindex-- {
-		checkstate, _ := New(types.EmptyRootHash, state.Database())
-		for _, action := range test.actions[:test.snapshots[sindex]] {
-			action.fn(action, checkstate)
-		}
 		state.RevertToSnapshot(snapshotRevs[sindex])
-		if err := test.checkEqual(state, checkstate); err != nil {
+		if err := test.checkEqual(state, checkstates[sindex]); err != nil {
 			test.err = fmt.Errorf("state mismatch after revert to snapshot %d\n%v", sindex, err)
 			return false
 		}

rpc/client_test.go

@@ -595,7 +595,7 @@ func TestClientSubscriptionChannelClose(t *testing.T) {
 
 	for i := 0; i < 100; i++ {
 		ch := make(chan int, 100)
-		sub, err := client.Subscribe(context.Background(), "nftest", ch, "someSubscription", maxClientSubscriptionBuffer-1, 1)
+		sub, err := client.Subscribe(context.Background(), "nftest", ch, "someSubscription", 100, 1)
 		if err != nil {
 			t.Fatal(err)
 		}