Drop checkpoints from #nonce_limiter_update

apps/arweave/include/ar.hrl

@@ -406,7 +406,6 @@
 -record(nonce_limiter_update, {
 	session_key,
 	session,
-	checkpoints,
 	is_partial = true
 }).
 

apps/arweave/src/ar_nonce_limiter.erl

@@ -647,7 +647,8 @@ handle_cast({validated_steps, Args}, State) ->
 							{step_number, StepNumber}]),
 						{_, Steps2} =
 							get_step_range(Steps, StepNumber, CurrentStepNumber + 1, StepNumber),
-						update_session(Session, StepNumber, LastStepCheckpoints, Steps2, #{});
+						update_session(Session, StepNumber,
+								#{ StepNumber => LastStepCheckpoints }, Steps2);
 					false ->
 						Session
 				end,
@@ -718,7 +719,8 @@ handle_info({computed, Args}, State) ->
 				{output, ar_util:encode(Output)}]),
 			{noreply, State};
 		true ->
-			Session2 = update_session(Session, StepNumber, Checkpoints, [Output], #{}),
+			Session2 = update_session(Session, StepNumber,
+					#{ StepNumber => Checkpoints }, [Output]),
 			State2 = cache_session(State, CurrentSessionKey, Session2),
 			?LOG_DEBUG([{event, new_vdf_step}, {source, computed},
 				{session_key, encode_session_key(CurrentSessionKey)}, {step_number, StepNumber}]),
@@ -747,11 +749,10 @@ session_key(NextSeed, StepNumber, NextVDFDifficulty) ->
 get_session(SessionKey, #state{ session_by_key = SessionByKey }) ->
 	maps:get(SessionKey, SessionByKey, not_found).
 
-update_session(Session, StepNumber, Checkpoints, Steps, StepCheckpointsMap) ->
+update_session(Session, StepNumber, StepCheckpointsMap, Steps) ->
 	#vdf_session{ step_checkpoints_map = Map } = Session,
-	Map2 = maps:put(StepNumber, Checkpoints, Map),
-	Map3 = maps:merge(StepCheckpointsMap, Map2),
-	update_session(Session#vdf_session{ step_checkpoints_map = Map3 }, StepNumber, Steps).
+	Map2 = maps:merge(StepCheckpointsMap, Map),
+	update_session(Session#vdf_session{ step_checkpoints_map = Map2 }, StepNumber, Steps).
 
 update_session(Session, StepNumber, Steps) ->
 	#vdf_session{ steps = CurrentSteps } = Session,
@@ -1075,7 +1076,7 @@ apply_external_update2(Update, State) ->
 			session = #vdf_session{
 				step_checkpoints_map = StepCheckpointsMap,
 				prev_session_key = PrevSessionKey, step_number = StepNumber } = Session,
-			checkpoints = Checkpoints, is_partial = IsPartial } = Update,
+			is_partial = IsPartial } = Update,
 	{_SessionSeed, SessionInterval, _SessionVDFDifficulty} = SessionKey,
 	case get_session(SessionKey, State) of
 		not_found ->
@@ -1114,8 +1115,8 @@ apply_external_update2(Update, State) ->
 			case CurrentStepNumber + 1 == StepNumber of
 				true ->
 					[Output | _] = Session#vdf_session.steps,
-					CurrentSession2 = update_session(CurrentSession, StepNumber, Checkpoints,
-							[Output], StepCheckpointsMap),
+					CurrentSession2 = update_session(CurrentSession, StepNumber,
+							StepCheckpointsMap, [Output]),
 					State2 = apply_external_update3(State, SessionKey, CurrentSession2, [Output]),
 					{reply, ok, State2};
 				false ->

apps/arweave/src/ar_nonce_limiter_server.erl

@@ -118,13 +118,12 @@ make_nonce_limiter_update(_SessionKey, not_found, _IsPartial) ->
 	not_found;
 make_nonce_limiter_update(SessionKey, Session, IsPartial) ->
 	StepNumber = Session#vdf_session.step_number,
-	Checkpoints = maps:get(StepNumber, Session#vdf_session.step_checkpoints_map, []),
 	StepCheckpointsMap = Session#vdf_session.step_checkpoints_map,
 	%% Clear the step_checkpoints_map to cut down on the amount of data pushed to each client.
 	RecentStepNumbers = get_recent_step_numbers(StepNumber),
 	StepCheckpointsMap2 = maps:with(RecentStepNumbers, StepCheckpointsMap),
 	#nonce_limiter_update{ session_key = SessionKey,
-			is_partial = IsPartial, checkpoints = Checkpoints,
+			is_partial = IsPartial,
 			session = Session#vdf_session{ step_checkpoints_map = StepCheckpointsMap2 } }.
 
 get_recent_step_numbers(StepNumber) ->

apps/arweave/src/ar_serialize.erl

@@ -363,7 +363,9 @@ binary_to_block_time_history(_Rest, _BlockTimeHistory) ->
 %% by nodes that compute their own VDF and never need to be shared from VDF server to VDF client.
 nonce_limiter_update_to_binary(2 = _Format, #nonce_limiter_update{
 			session_key = {NextSeed, Interval, NextVDFDifficulty},
-		session = Session, checkpoints = Checkpoints, is_partial = IsPartial }) ->
+		session = Session, is_partial = IsPartial }) ->
+	#vdf_session{ step_number = StepNumber, step_checkpoints_map = Map } = Session,
+	Checkpoints = maps:get(StepNumber, Map, []),
 	IsPartialBin = case IsPartial of true -> << 1:8 >>; _ -> << 0:8 >> end,
 	CheckpointLen = length(Checkpoints),
 	<< NextSeed:48/binary, (ar_serialize:encode_int(NextVDFDifficulty, 8))/binary,
@@ -432,9 +434,9 @@ binary_to_nonce_limiter_update(2, % Format
 		when UpperBoundSize > 0, StepsLen > 0, CheckpointLen == ?VDF_CHECKPOINT_COUNT_IN_STEP ->
 	NextUpperBound2 = case NextUpperBoundSize of 0 -> undefined; _ -> NextUpperBound end,
 	Update = #nonce_limiter_update{ session_key = {NextSeed, Interval, NextVDFDifficulty},
-			checkpoints = parse_32b_list(Checkpoints),
 			is_partial = case IsPartial of 0 -> false; _ -> true end,
 			session = Session = #vdf_session{ step_number = StepNumber, seed = Seed,
+					step_checkpoints_map = #{ StepNumber => parse_32b_list(Checkpoints) },
 					upper_bound = UpperBound, next_upper_bound = NextUpperBound2,
 					steps = parse_32b_list(Steps) } },
 	case decode_session_key(PrevSessionKeyBin) of
@@ -462,7 +464,6 @@ binary_to_nonce_limiter_update(3, % Format = 3.
 	NextUpperBound2 = case NextUpperBoundSize of 0 -> undefined; _ -> NextUpperBound end,
 	StepCheckpointsMap = decode_step_checkpoints_map(CheckpointsMapBin, #{}),
 	Update = #nonce_limiter_update{ session_key = {NextSeed, Interval, NextVDFDifficulty},
-			checkpoints = maps:get(StepNumber, StepCheckpointsMap),
 			is_partial = case IsPartial of 0 -> false; _ -> true end,
 			session = Session = #vdf_session{ step_number = StepNumber, seed = Seed,
 					upper_bound = UpperBound, next_upper_bound = NextUpperBound2,