Add receive_hash option for the blocks_info RPC (#3702)

Added the function nano::node::find_receive_block_by_send_hash to
find the receive block linked with a send block for better code reuse.

Co-authored-by: Dimitrios Siganos <dimitris@siganos.org>
Co-authored-by: Thiago Silva <thiago@nano.org>

nano/node/json_handler.cpp

@@ -1239,6 +1239,7 @@ void nano::json_handler::blocks_info ()
 {
 	bool const pending = request.get<bool> ("pending", false);
 	bool const receivable = request.get<bool> ("receivable", pending);
+	bool const receive_hash = request.get<bool> ("receive_hash", false);
 	bool const source = request.get<bool> ("source", false);
 	bool const json_block_l = request.get<bool> ("json_block", false);
 	bool const include_not_found = request.get<bool> ("include_not_found", false);
@@ -1291,16 +1292,47 @@ void nano::json_handler::blocks_info ()
 						auto subtype (nano::state_subtype (block->sideband ().details));
 						entry.put ("subtype", subtype);
 					}
-					if (receivable)
+					if (receivable || receive_hash)
 					{
-						bool exists (false);
 						auto destination (node.ledger.block_destination (transaction, *block));
-						if (!destination.is_zero ())
+						if (destination.is_zero ())
 						{
-							exists = node.store.pending.exists (transaction, nano::pending_key (destination, hash));
+							if (receivable)
+							{
+								entry.put ("pending", "0");
+								entry.put ("receivable", "0");
+							}
+							if (receive_hash)
+							{
+								entry.put ("receive_hash", nano::block_hash (0).to_string ());
+							}
+						}
+						else if (node.store.pending.exists (transaction, nano::pending_key (destination, hash)))
+						{
+							if (receivable)
+							{
+								entry.put ("pending", "1");
+								entry.put ("receivable", "1");
+							}
+							if (receive_hash)
+							{
+								entry.put ("receive_hash", nano::block_hash (0).to_string ());
+							}
+						}
+						else
+						{
+							if (receivable)
+							{
+								entry.put ("pending", "0");
+								entry.put ("receivable", "0");
+							}
+							if (receive_hash)
+							{
+								std::shared_ptr<nano::block> receive_block = node.ledger.find_receive_block_by_send_hash (transaction, destination, hash);
+								std::string receive_hash = receive_block ? receive_block->hash ().to_string () : nano::block_hash (0).to_string ();
+								entry.put ("receive_hash", receive_hash);
+							}
 						}
-						entry.put ("pending", exists ? "1" : "0");
-						entry.put ("receivable", exists ? "1" : "0");
 					}
 					if (source)
 					{

nano/rpc_test/rpc.cpp

@@ -16,7 +16,9 @@
 #include <boost/property_tree/json_parser.hpp>
 
 #include <algorithm>
+#include <map>
 #include <tuple>
+#include <utility>
 
 using namespace std::chrono_literals;
 
@@ -4062,6 +4064,8 @@ TEST (rpc, blocks_info)
 			ASSERT_FALSE (blocks_text.empty ());
 			boost::optional<std::string> receivable (blocks.second.get_optional<std::string> ("receivable"));
 			ASSERT_FALSE (receivable.is_initialized ());
+			boost::optional<std::string> receive_hash (blocks.second.get_optional<std::string> ("receive_hash"));
+			ASSERT_FALSE (receive_hash.is_initialized ());
 			boost::optional<std::string> source (blocks.second.get_optional<std::string> ("source_account"));
 			ASSERT_FALSE (source.is_initialized ());
 			std::string balance_text (blocks.second.get<std::string> ("balance"));
@@ -4101,16 +4105,97 @@ TEST (rpc, blocks_info)
 	}
 	request.put ("source", "true");
 	request.put ("receivable", "1");
+	request.put ("receive_hash", "1");
 	{
 		auto response (wait_response (system, rpc_ctx, request));
 		for (auto & blocks : response.get_child ("blocks"))
 		{
 			ASSERT_EQ ("0", blocks.second.get<std::string> ("source_account"));
 			ASSERT_EQ ("0", blocks.second.get<std::string> ("receivable"));
+			std::string receive_hash (blocks.second.get<std::string> ("receive_hash"));
+			ASSERT_EQ (nano::block_hash (0).to_string (), receive_hash);
 		}
 	}
 }
 
+/**
+ * Test to check the receive_hash option of blocks_info rpc command.
+ * The test does 4 sends from genesis to key1.
+ * Then it does 4 receives, one for each send.
+ * Then it issues the blocks_info RPC command and checks that the receive block of each send block is correctly found.
+ */
+TEST (rpc, blocks_info_receive_hash)
+{
+	nano::system system;
+	auto node = add_ipc_enabled_node (system);
+	nano::keypair key1;
+	system.wallet (0)->insert_adhoc (key1.prv);
+	system.wallet (0)->insert_adhoc (nano::dev::genesis_key.prv);
+
+	// do 4 sends
+	auto send1 = system.wallet (0)->send_action (nano::dev::genesis_key.pub, key1.pub, 1);
+	auto send2 = system.wallet (0)->send_action (nano::dev::genesis_key.pub, key1.pub, 2);
+	auto send3 = system.wallet (0)->send_action (nano::dev::genesis_key.pub, key1.pub, 3);
+	auto send4 = system.wallet (0)->send_action (nano::dev::genesis_key.pub, key1.pub, 4);
+
+	// do 4 receives, mix up the ordering a little
+	auto recv1 (system.wallet (0)->receive_action (send1->hash (), key1.pub, node->config.receive_minimum.number (), send1->link ().as_account ()));
+	auto recv4 (system.wallet (0)->receive_action (send4->hash (), key1.pub, node->config.receive_minimum.number (), send4->link ().as_account ()));
+	auto recv3 (system.wallet (0)->receive_action (send3->hash (), key1.pub, node->config.receive_minimum.number (), send3->link ().as_account ()));
+	auto recv2 (system.wallet (0)->receive_action (send2->hash (), key1.pub, node->config.receive_minimum.number (), send2->link ().as_account ()));
+
+	// function to check that all 4 receive blocks are cemented
+	auto all_blocks_cemented = [node, &key1] () -> bool {
+		nano::confirmation_height_info info;
+		if (node->store.confirmation_height.get (node->store.tx_begin_read (), key1.pub, info))
+		{
+			return false;
+		}
+		return info.height == 4;
+	};
+
+	ASSERT_TIMELY (5s, all_blocks_cemented ());
+	ASSERT_EQ (node->ledger.account_balance (node->store.tx_begin_read (), key1.pub, true), 10);
+
+	// create the RPC request
+	boost::property_tree::ptree request;
+	boost::property_tree::ptree hashes;
+	boost::property_tree::ptree child;
+	child.put ("", send1->hash ().to_string ());
+	hashes.push_back (std::make_pair ("", child));
+	child.put ("", send2->hash ().to_string ());
+	hashes.push_back (std::make_pair ("", child));
+	child.put ("", send3->hash ().to_string ());
+	hashes.push_back (std::make_pair ("", child));
+	child.put ("", send4->hash ().to_string ());
+	hashes.push_back (std::make_pair ("", child));
+	request.put ("action", "blocks_info");
+	request.add_child ("hashes", hashes);
+	request.put ("receive_hash", "true");
+	request.put ("json_block", "true");
+
+	// send the request
+	auto const rpc_ctx = add_rpc (system, node);
+	auto response = wait_response (system, rpc_ctx, request);
+
+	// create a map of the expected receives hashes for each send hash
+	std::map<std::string, std::string> send_recv_map{
+		{ send1->hash ().to_string (), recv1->hash ().to_string () },
+		{ send2->hash ().to_string (), recv2->hash ().to_string () },
+		{ send3->hash ().to_string (), recv3->hash ().to_string () },
+		{ send4->hash ().to_string (), recv4->hash ().to_string () },
+	};
+
+	for (auto & blocks : response.get_child ("blocks"))
+	{
+		auto hash = blocks.first;
+		std::string receive_hash = blocks.second.get<std::string> ("receive_hash");
+		ASSERT_EQ (receive_hash, send_recv_map[hash]);
+		send_recv_map.erase (hash);
+	}
+	ASSERT_EQ (send_recv_map.size (), 0);
+}
+
 TEST (rpc, blocks_info_subtype)
 {
 	nano::system system;

nano/secure/common.hpp

@@ -229,9 +229,14 @@ class confirmation_height_info final
 public:
 	confirmation_height_info () = default;
 	confirmation_height_info (uint64_t, nano::block_hash const &);
+
 	void serialize (nano::stream &) const;
 	bool deserialize (nano::stream &);
+
+	/** height of the cemented frontier */
 	uint64_t height{};
+
+	/** hash of the highest cemented block, the cemented/confirmed frontier */
 	nano::block_hash frontier{};
 };
 

nano/secure/ledger.cpp

@@ -1237,6 +1237,54 @@ std::array<nano::block_hash, 2> nano::ledger::dependent_blocks (nano::transactio
 	return visitor.result;
 }
 
+/** Given the block hash of a send block, find the associated receive block that receives that send.
+ *  The send block hash is not checked in any way, it is assumed to be correct.
+ * @return Return the receive block on success and null on failure
+ */
+std::shared_ptr<nano::block> nano::ledger::find_receive_block_by_send_hash (nano::transaction const & transaction, nano::account const & destination, nano::block_hash const & send_block_hash)
+{
+	std::shared_ptr<nano::block> result;
+	debug_assert (send_block_hash != 0);
+
+	// get the cemented frontier
+	nano::confirmation_height_info info;
+	if (store.confirmation_height.get (transaction, destination, info))
+	{
+		return nullptr;
+	}
+	auto possible_receive_block = store.block.get (transaction, info.frontier);
+
+	// walk down the chain until the source field of a receive block matches the send block hash
+	while (possible_receive_block != nullptr)
+	{
+		// if source is non-zero then it is a legacy receive or open block
+		nano::block_hash source = possible_receive_block->source ();
+
+		// if source is zero then it could be a state block, which needs a different kind of access
+		auto state_block = dynamic_cast<nano::state_block const *> (possible_receive_block.get ());
+		if (state_block != nullptr)
+		{
+			// we read the block from the database, so we expect it to have sideband
+			debug_assert (state_block->has_sideband ());
+			if (state_block->sideband ().details.is_receive)
+			{
+				source = state_block->hashables.link.as_block_hash ();
+			}
+		}
+
+		if (send_block_hash == source)
+		{
+			// we have a match
+			result = possible_receive_block;
+			break;
+		}
+
+		possible_receive_block = store.block.get (transaction, possible_receive_block->previous ());
+	}
+
+	return result;
+}
+
 nano::account const & nano::ledger::epoch_signer (nano::link const & link_a) const
 {
 	return constants.epochs.signer (constants.epochs.epoch (link_a));

nano/secure/ledger.hpp

@@ -63,6 +63,7 @@ public:
 	bool dependents_confirmed (nano::transaction const &, nano::block const &) const;
 	bool is_epoch_link (nano::link const &) const;
 	std::array<nano::block_hash, 2> dependent_blocks (nano::transaction const &, nano::block const &) const;
+	std::shared_ptr<nano::block> find_receive_block_by_send_hash (nano::transaction const & transaction, nano::account const & destination, nano::block_hash const & send_block_hash);
 	nano::account const & epoch_signer (nano::link const &) const;
 	nano::link const & epoch_link (nano::epoch) const;
 	std::multimap<uint64_t, uncemented_info, std::greater<>> unconfirmed_frontiers () const;

nano/secure/store.hpp

@@ -725,7 +725,14 @@ class confirmation_height_store
 {
 public:
 	virtual void put (nano::write_transaction const & transaction_a, nano::account const & account_a, nano::confirmation_height_info const & confirmation_height_info_a) = 0;
+
+	/** Retrieves confirmation height info relating to an account.
+	 *  The parameter confirmation_height_info_a is always written.
+	 *  On error, the confirmation height and frontier hash are set to 0.
+	 *  Ruturns true on error, false on success.
+	 */
 	virtual bool get (nano::transaction const & transaction_a, nano::account const & account_a, nano::confirmation_height_info & confirmation_height_info_a) = 0;
+
 	virtual bool exists (nano::transaction const & transaction_a, nano::account const & account_a) const = 0;
 	virtual void del (nano::write_transaction const & transaction_a, nano::account const & account_a) = 0;
 	virtual uint64_t count (nano::transaction const & transaction_a) = 0;