Speedup SideChain::get_outputs_blob()

src/block_cache.cpp

@@ -198,7 +198,7 @@ void BlockCache::load_all(SideChain& side_chain, P2PServer& server)
 			continue;
 		}
 
-		if (block.deserialize(data + sizeof(uint32_t), n, side_chain) == 0) {
+		if (block.deserialize(data + sizeof(uint32_t), n, side_chain, uv_default_loop_checked()) == 0) {
 			server.add_cached_block(block);
 			++blocks_loaded;
 		}

src/block_template.cpp

@@ -548,7 +548,7 @@ void BlockTemplate::update(const MinerData& data, const Mempool& mempool, Wallet
 		buf.insert(buf.end(), m_poolBlockTemplate->m_sideChainData.begin(), m_poolBlockTemplate->m_sideChainData.end());
 
 		PoolBlock check;
-		const int result = check.deserialize(buf.data(), buf.size(), m_pool->side_chain());
+		const int result = check.deserialize(buf.data(), buf.size(), m_pool->side_chain(), nullptr);
 		if (result != 0) {
 			LOGERR(1, "pool block blob generation and/or parsing is broken, error " << result);
 		}
@@ -1077,7 +1077,7 @@ void BlockTemplate::submit_sidechain_block(uint32_t template_id, uint32_t nonce,
 			buf.insert(buf.end(), m_poolBlockTemplate->m_sideChainData.begin(), m_poolBlockTemplate->m_sideChainData.end());
 
 			PoolBlock check;
-			const int result = check.deserialize(buf.data(), buf.size(), side_chain);
+			const int result = check.deserialize(buf.data(), buf.size(), side_chain, nullptr);
 			if (result != 0) {
 				LOGERR(1, "pool block blob generation and/or parsing is broken, error " << result);
 			}

src/p2p_server.cpp

@@ -900,7 +900,7 @@ int P2PServer::deserialize_block(const uint8_t* buf, uint32_t size)
 		result = m_blockDeserializeResult;
 	}
 	else {
-		result = m_block->deserialize(buf, size, m_pool->side_chain());
+		result = m_block->deserialize(buf, size, m_pool->side_chain(), &m_loop);
 		m_blockDeserializeBuf.assign(buf, buf + size);
 		m_blockDeserializeResult = result;
 		m_lookForMissingBlocks = true;

src/pool_block.h

@@ -139,7 +139,7 @@ struct PoolBlock
 	void serialize_mainchain_data(uint32_t nonce, uint32_t extra_nonce, const hash& sidechain_hash);
 	void serialize_sidechain_data();
 
-	int deserialize(const uint8_t* data, size_t size, const SideChain& sidechain);
+	int deserialize(const uint8_t* data, size_t size, const SideChain& sidechain, uv_loop_t* loop);
 	void reset_offchain_data();
 
 	bool get_pow_hash(RandomX_Hasher_Base* hasher, uint64_t height, const hash& seed_hash, hash& pow_hash);

src/pool_block_parser.inl

@@ -23,7 +23,7 @@ namespace p2pool {
 // Since data here can come from external and possibly malicious sources, check everything
 // Only the syntax (i.e. the serialized block binary format) and the keccak hash are checked here
 // Semantics must also be checked elsewhere before accepting the block (PoW, reward split between miners, difficulty calculation and so on)
-int PoolBlock::deserialize(const uint8_t* data, size_t size, const SideChain& sidechain)
+int PoolBlock::deserialize(const uint8_t* data, size_t size, const SideChain& sidechain, uv_loop_t* loop)
 {
 	try {
 		// Sanity check
@@ -272,7 +272,7 @@ int PoolBlock::deserialize(const uint8_t* data, size_t size, const SideChain& si
 			return __LINE__;
 		}
 
-		if ((num_outputs == 0) && !sidechain.get_outputs_blob(this, total_reward, outputs_blob)) {
+		if ((num_outputs == 0) && !sidechain.get_outputs_blob(this, total_reward, outputs_blob, loop)) {
 			return __LINE__;
 		}
 

src/side_chain.cpp

@@ -682,7 +682,7 @@ bool SideChain::get_block_blob(const hash& id, std::vector<uint8_t>& blob) const
 	return true;
 }
 
-bool SideChain::get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::vector<uint8_t>& blob) const
+bool SideChain::get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::vector<uint8_t>& blob, uv_loop_t* loop) const
 {
 	blob.clear();
 
@@ -719,6 +719,60 @@ bool SideChain::get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::v
 
 	const size_t n = tmpShares.size();
 
+	// Helper jobs call get_eph_public_key with indices in descending order
+	// Current thread will process indices in ascending order so when they meet, everything will be cached
+
+	std::atomic<int> counter{ 0 };
+	std::atomic<int> num_helper_jobs_finished{ 0 };
+	int num_helper_jobs_started = 0;
+
+	if (loop) {
+		constexpr size_t HELPER_JOBS_COUNT = 4;
+
+		struct Work
+		{
+			uv_work_t req;
+			const std::vector<MinerShare>& tmpShares;
+			const hash& txkeySec;
+			std::atomic<int>& counter;
+			std::atomic<int>& num_helper_jobs_finished;
+
+			// Fix MSVC warnings
+			Work() = delete;
+			Work& operator=(Work&&) = delete;
+		};
+
+		counter = static_cast<int>(n) - 1;
+		num_helper_jobs_started = HELPER_JOBS_COUNT;
+
+		for (size_t i = 0; i < HELPER_JOBS_COUNT; ++i) {
+			Work* w = new Work{ {}, tmpShares, block->m_txkeySec, counter, num_helper_jobs_finished };
+			w->req.data = w;
+
+			const int err = uv_queue_work(loop, &w->req,
+				[](uv_work_t* req)
+				{
+					Work* work = reinterpret_cast<Work*>(req->data);
+					hash eph_public_key;
+
+					int index;
+					while ((index = work->counter.fetch_sub(1)) >= 0) {
+						uint8_t view_tag;
+						work->tmpShares[index].m_wallet->get_eph_public_key(work->txkeySec, static_cast<size_t>(index), eph_public_key, view_tag);
+					}
+
+					++work->num_helper_jobs_finished;
+					delete work;
+				}, nullptr);
+
+			if (err) {
+				LOGERR(1, "get_outputs_blob: uv_queue_work failed, error " << uv_err_name(err));
+				--num_helper_jobs_started;
+				delete w;
+			}
+		}
+	}
+
 	blob.reserve(n * 39 + 64);
 
 	writeVarint(n, blob);
@@ -730,6 +784,13 @@ bool SideChain::get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::v
 
 	hash eph_public_key;
 	for (size_t i = 0; i < n; ++i) {
+		// stop helper jobs when they meet with current thread
+		const int c = counter.load();
+		if ((c >= 0) && (static_cast<int>(i) >= c)) {
+			// this will cause all helper jobs to finish immediately
+			counter = -1;
+		}
+
 		writeVarint(tmpRewards[i], blob);
 
 		blob.emplace_back(tx_type);
@@ -747,6 +808,15 @@ bool SideChain::get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::v
 		block->m_outputs.emplace_back(tmpRewards[i], eph_public_key, tx_type, view_tag);
 	}
 
+	if (loop) {
+		// this will cause all helper jobs to finish immediately
+		counter = -1;
+
+		while (num_helper_jobs_finished < num_helper_jobs_started) {
+			std::this_thread::yield();
+		}
+	}
+
 	return true;
 }
 

src/side_chain.h

@@ -56,7 +56,7 @@ public:
 	void watch_mainchain_block(const ChainMain& data, const hash& possible_id);
 
 	bool get_block_blob(const hash& id, std::vector<uint8_t>& blob) const;
-	bool get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::vector<uint8_t>& blob) const;
+	bool get_outputs_blob(PoolBlock* block, uint64_t total_reward, std::vector<uint8_t>& blob, uv_loop_t* loop) const;
 
 	void print_status() const;
 	double get_reward_share(const Wallet& w) const;

tests/src/pool_block_tests.cpp

@@ -49,7 +49,7 @@ TEST(pool_block, deserialize)
 	f.read(reinterpret_cast<char*>(buf.data()), buf.size());
 	ASSERT_EQ(f.good(), true);
 
-	ASSERT_EQ(b.deserialize(buf.data(), buf.size(), sidechain), 0);
+	ASSERT_EQ(b.deserialize(buf.data(), buf.size(), sidechain, nullptr), 0);
 
 	ASSERT_EQ(b.m_mainChainData.size(), 5607);
 	ASSERT_EQ(b.m_mainChainHeaderSize, 43);
@@ -121,7 +121,7 @@ TEST(pool_block, verify)
 			p += sizeof(uint32_t);
 
 			ASSERT_TRUE(p + n <= e);
-			ASSERT_EQ(b.deserialize(p, n, sidechain), 0);
+			ASSERT_EQ(b.deserialize(p, n, sidechain, nullptr), 0);
 			p += n;
 
 			sidechain.add_block(b);