ar_data_sync: Skip unpacking if the chunk was downloaded from the local peer

apps/arweave/src/ar_metrics.erl

@@ -158,10 +158,11 @@ register() ->
 	]),
 	prometheus_gauge:new([
 		{name, v2_index_data_size_by_packing},
-		{labels, [store_id, packing, partition_number, storage_module_size, storage_module_index]},
+		{labels, [store_id, packing, partition_number, storage_module_size, storage_module_index,
+			  packing_difficulty]},
 		{help, "The size (in bytes) of the data stored and indexed. Grouped by the "
 				"store ID, packing, partition number, storage module size, "
-				"and storage module index."}
+				"storage module index, and packing difficulty."}
 	]),
 
 	%% Disk pool.

apps/arweave/src/ar_mining_stats.erl

@@ -161,9 +161,12 @@ set_storage_module_data_size(
 		StoreID, Packing, PartitionNumber, StorageModuleSize, StorageModuleIndex, DataSize) ->
 	StoreLabel = ar_storage_module:label_by_id(StoreID),
 	PackingLabel = ar_storage_module:packing_label(Packing),
-	try
+	try	
+		PackingDifficulty = get_packing_difficulty(Packing),
 		prometheus_gauge:set(v2_index_data_size_by_packing,
-			[StoreLabel, PackingLabel, PartitionNumber, StorageModuleSize, StorageModuleIndex],
+			[StoreLabel, PackingLabel, PartitionNumber,
+			 StorageModuleSize, StorageModuleIndex,
+			 PackingDifficulty],
 			DataSize),
 		ets:insert(?MODULE, {
 			{partition, PartitionNumber, storage_module, StoreID, packing, Packing}, DataSize})

apps/arweave/src/ar_node_worker.erl

@@ -383,7 +383,12 @@ handle_info({event, node_state, _Event}, State) ->
 handle_info({event, nonce_limiter, initialized}, State) ->
 	[{_, {Height, Blocks, BI}}] = ets:lookup(node_state, join_state),
 	ar_storage:store_block_index(BI),
-	B = hd(Blocks),
+	RecentBI = lists:sublist(BI, ?BLOCK_INDEX_HEAD_LEN),
+	Current = element(1, hd(RecentBI)),
+	RecentBlocks = lists:sublist(Blocks, ?STORE_BLOCKS_BEHIND_CURRENT),
+	RecentBlocks2 = set_poa_caches(RecentBlocks),
+	ar_block_cache:initialize_from_list(block_cache, RecentBlocks2),
+	B = hd(RecentBlocks2),
 	RewardHistory = [{H, {Addr, HashRate, Reward, Denomination}}
 			|| {{Addr, HashRate, Reward, Denomination}, {H, _, _}}
 			<- lists:zip(B#block.reward_history,
@@ -394,15 +399,11 @@ handle_info({event, nonce_limiter, initialized}, State) ->
 			<- lists:zip(B#block.block_time_history,
 					lists:sublist(BI, length(B#block.block_time_history)))],
 	ar_storage:store_block_time_history_part2(BlockTimeHistory),
-	RecentBI = lists:sublist(BI, ?BLOCK_INDEX_HEAD_LEN),
 	Height = B#block.height,
 	ar_disk_cache:write_block(B),
 	ar_data_sync:join(RecentBI),
 	ar_header_sync:join(Height, RecentBI, Blocks),
 	ar_tx_blacklist:start_taking_down(),
-	Current = element(1, hd(RecentBI)),
-	ar_block_cache:initialize_from_list(block_cache,
-			lists:sublist(Blocks, ?STORE_BLOCKS_BEHIND_CURRENT)),
 	BlockTXPairs = [block_txs_pair(Block) || Block <- Blocks],
 	{BlockAnchors, RecentTXMap} = get_block_anchors_and_recent_txs_map(BlockTXPairs),
 	{Rate, ScheduledRate} = {B#block.usd_to_ar_rate, B#block.scheduled_usd_to_ar_rate},
@@ -1755,6 +1756,39 @@ read_recent_blocks3([{BH, _, _} | BI], BlocksToRead, Blocks) ->
 			not_found
 	end.
 
+set_poa_caches([]) ->
+	[];
+set_poa_caches([B | Blocks]) ->
+	[set_poa_cache(B) | set_poa_caches(Blocks)].
+
+set_poa_cache(B) ->
+	PoA1 = B#block.poa,
+	PoA2 = B#block.poa2,
+	MiningAddress = B#block.reward_addr,
+	PackingDifficulty = B#block.packing_difficulty,
+	Nonce = B#block.nonce,
+	RecallByte1 = B#block.recall_byte,
+	RecallByte2 = B#block.recall_byte2,
+	Packing = ar_block:get_packing(PackingDifficulty, MiningAddress),
+	PoACache = compute_poa_cache(B, PoA1, RecallByte1, Nonce, Packing),
+	B2 = B#block{ poa_cache = PoACache },
+	%% Compute PoA2 cache if PoA2 is present.
+	case RecallByte2 of
+		undefined ->
+			B2;
+		_ ->
+			PoA2Cache = compute_poa_cache(B, PoA2, RecallByte2, Nonce, Packing),
+			B2#block{ poa2_cache = PoA2Cache }
+	end.
+
+compute_poa_cache(B, PoA, RecallByte, Nonce, Packing) ->
+	PackingDifficulty = B#block.packing_difficulty,
+	SubChunkIndex = ar_block:get_sub_chunk_index(PackingDifficulty, Nonce),
+	{BlockStart, BlockEnd, TXRoot} = ar_block_index:get_block_bounds(RecallByte),
+	BlockSize = BlockEnd - BlockStart,
+	ChunkID = ar_tx:generate_chunk_id(PoA#poa.chunk),
+	{{BlockStart, RecallByte, TXRoot, BlockSize, Packing, SubChunkIndex}, ChunkID}.
+
 dump_mempool(TXs, MempoolSize) ->
 	SerializedTXs = maps:map(fun(_, {TX, St}) -> {ar_serialize:tx_to_binary(TX), St} end, TXs),
 	case ar_storage:write_term(mempool, {SerializedTXs, MempoolSize}) of