Add target to getblock(header) in RPC and REST

Author: Sjors

src/bench/rpc_blockchain.cpp

@@ -48,8 +48,9 @@ struct TestBlockAndIndex {
 static void BlockToJsonVerbose(benchmark::Bench& bench)
 {
     TestBlockAndIndex data;
+    const uint256 pow_limit{data.testing_setup->m_node.chainman->GetParams().GetConsensus().powLimit};
     bench.run([&] {
-        auto univalue = blockToJSON(data.testing_setup->m_node.chainman->m_blockman, data.block, data.blockindex, data.blockindex, TxVerbosity::SHOW_DETAILS_AND_PREVOUT);
+        auto univalue = blockToJSON(data.testing_setup->m_node.chainman->m_blockman, data.block, data.blockindex, data.blockindex, TxVerbosity::SHOW_DETAILS_AND_PREVOUT, pow_limit);
         ankerl::nanobench::doNotOptimizeAway(univalue);
     });
 }
@@ -59,7 +60,8 @@ BENCHMARK(BlockToJsonVerbose, benchmark::PriorityLevel::HIGH);
 static void BlockToJsonVerboseWrite(benchmark::Bench& bench)
 {
     TestBlockAndIndex data;
-    auto univalue = blockToJSON(data.testing_setup->m_node.chainman->m_blockman, data.block, data.blockindex, data.blockindex, TxVerbosity::SHOW_DETAILS_AND_PREVOUT);
+    const uint256 pow_limit{data.testing_setup->m_node.chainman->GetParams().GetConsensus().powLimit};
+    auto univalue = blockToJSON(data.testing_setup->m_node.chainman->m_blockman, data.block, data.blockindex, data.blockindex, TxVerbosity::SHOW_DETAILS_AND_PREVOUT, pow_limit);
     bench.run([&] {
         auto str = univalue.write();
         ankerl::nanobench::doNotOptimizeAway(str);

src/rest.cpp

@@ -225,10 +225,10 @@ static bool rest_headers(const std::any& context,
     const CBlockIndex* tip = nullptr;
     std::vector<const CBlockIndex*> headers;
     headers.reserve(*parsed_count);
+    ChainstateManager* maybe_chainman = GetChainman(context, req);
+    if (!maybe_chainman) return false;
+    ChainstateManager& chainman = *maybe_chainman;
     {
-        ChainstateManager* maybe_chainman = GetChainman(context, req);
-        if (!maybe_chainman) return false;
-        ChainstateManager& chainman = *maybe_chainman;
         LOCK(cs_main);
         CChain& active_chain = chainman.ActiveChain();
         tip = active_chain.Tip();
@@ -268,7 +268,7 @@ static bool rest_headers(const std::any& context,
     case RESTResponseFormat::JSON: {
         UniValue jsonHeaders(UniValue::VARR);
         for (const CBlockIndex *pindex : headers) {
-            jsonHeaders.push_back(blockheaderToJSON(*tip, *pindex));
+            jsonHeaders.push_back(blockheaderToJSON(*tip, *pindex, chainman.GetConsensus().powLimit));
         }
         std::string strJSON = jsonHeaders.write() + "\n";
         req->WriteHeader("Content-Type", "application/json");
@@ -341,7 +341,7 @@ static bool rest_block(const std::any& context,
         CBlock block{};
         DataStream block_stream{block_data};
         block_stream >> TX_WITH_WITNESS(block);
-        UniValue objBlock = blockToJSON(chainman.m_blockman, block, *tip, *pblockindex, tx_verbosity);
+        UniValue objBlock = blockToJSON(chainman.m_blockman, block, *tip, *pblockindex, tx_verbosity, chainman.GetConsensus().powLimit);
         std::string strJSON = objBlock.write() + "\n";
         req->WriteHeader("Content-Type", "application/json");
         req->WriteReply(HTTP_OK, strJSON);

src/rpc/blockchain.cpp

@@ -146,7 +146,7 @@ static const CBlockIndex* ParseHashOrHeight(const UniValue& param, ChainstateMan
     }
 }
 
-UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex)
+UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex, const uint256 pow_limit)
 {
     // Serialize passed information without accessing chain state of the active chain!
     AssertLockNotHeld(cs_main); // For performance reasons
@@ -164,6 +164,7 @@ UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex
     result.pushKV("mediantime", blockindex.GetMedianTimePast());
     result.pushKV("nonce", blockindex.nNonce);
     result.pushKV("bits", strprintf("%08x", blockindex.nBits));
+    result.pushKV("target", GetTarget(tip, pow_limit).GetHex());
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex.nChainWork.GetHex());
     result.pushKV("nTx", blockindex.nTx);
@@ -175,9 +176,9 @@ UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex
     return result;
 }
 
-UniValue blockToJSON(BlockManager& blockman, const CBlock& block, const CBlockIndex& tip, const CBlockIndex& blockindex, TxVerbosity verbosity)
+UniValue blockToJSON(BlockManager& blockman, const CBlock& block, const CBlockIndex& tip, const CBlockIndex& blockindex, TxVerbosity verbosity, const uint256 pow_limit)
 {
-    UniValue result = blockheaderToJSON(tip, blockindex);
+    UniValue result = blockheaderToJSON(tip, blockindex, pow_limit);
 
     result.pushKV("strippedsize", (int)::GetSerializeSize(TX_NO_WITNESS(block)));
     result.pushKV("size", (int)::GetSerializeSize(TX_WITH_WITNESS(block)));
@@ -554,6 +555,7 @@ static RPCHelpMan getblockheader()
                             {RPCResult::Type::NUM_TIME, "mediantime", "The median block time expressed in " + UNIX_EPOCH_TIME},
                             {RPCResult::Type::NUM, "nonce", "The nonce"},
                             {RPCResult::Type::STR_HEX, "bits", "nBits: compact representation of the block difficulty target"},
+                            {RPCResult::Type::STR_HEX, "target", "The difficulty target"},
                             {RPCResult::Type::NUM, "difficulty", "The difficulty"},
                             {RPCResult::Type::STR_HEX, "chainwork", "Expected number of hashes required to produce the current chain"},
                             {RPCResult::Type::NUM, "nTx", "The number of transactions in the block"},
@@ -577,8 +579,8 @@ static RPCHelpMan getblockheader()
 
     const CBlockIndex* pblockindex;
     const CBlockIndex* tip;
+    ChainstateManager& chainman = EnsureAnyChainman(request.context);
     {
-        ChainstateManager& chainman = EnsureAnyChainman(request.context);
         LOCK(cs_main);
         pblockindex = chainman.m_blockman.LookupBlockIndex(hash);
         tip = chainman.ActiveChain().Tip();
@@ -596,7 +598,7 @@ static RPCHelpMan getblockheader()
         return strHex;
     }
 
-    return blockheaderToJSON(*tip, *pblockindex);
+    return blockheaderToJSON(*tip, *pblockindex, chainman.GetConsensus().powLimit);
 },
     };
 }
@@ -728,6 +730,7 @@ static RPCHelpMan getblock()
                     {RPCResult::Type::NUM_TIME, "mediantime", "The median block time expressed in " + UNIX_EPOCH_TIME},
                     {RPCResult::Type::NUM, "nonce", "The nonce"},
                     {RPCResult::Type::STR_HEX, "bits", "nBits: compact representation of the block difficulty target"},
+                    {RPCResult::Type::STR_HEX, "target", "The difficulty target"},
                     {RPCResult::Type::NUM, "difficulty", "The difficulty"},
                     {RPCResult::Type::STR_HEX, "chainwork", "Expected number of hashes required to produce the chain up to this block (in hex)"},
                     {RPCResult::Type::NUM, "nTx", "The number of transactions in the block"},
@@ -802,7 +805,7 @@ static RPCHelpMan getblock()
         tx_verbosity = TxVerbosity::SHOW_DETAILS_AND_PREVOUT;
     }
 
-    return blockToJSON(chainman.m_blockman, block, *tip, *pblockindex, tx_verbosity);
+    return blockToJSON(chainman.m_blockman, block, *tip, *pblockindex, tx_verbosity, chainman.GetConsensus().powLimit);
 },
     };
 }

src/rpc/blockchain.h

@@ -36,10 +36,10 @@ static constexpr int NUM_GETBLOCKSTATS_PERCENTILES = 5;
 double GetDifficulty(const CBlockIndex& blockindex);
 
 /** Block description to JSON */
-UniValue blockToJSON(node::BlockManager& blockman, const CBlock& block, const CBlockIndex& tip, const CBlockIndex& blockindex, TxVerbosity verbosity) LOCKS_EXCLUDED(cs_main);
+UniValue blockToJSON(node::BlockManager& blockman, const CBlock& block, const CBlockIndex& tip, const CBlockIndex& blockindex, TxVerbosity verbosity, const uint256 pow_limit) LOCKS_EXCLUDED(cs_main);
 
 /** Block header to JSON */
-UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex) LOCKS_EXCLUDED(cs_main);
+UniValue blockheaderToJSON(const CBlockIndex& tip, const CBlockIndex& blockindex, const uint256 pow_limit) LOCKS_EXCLUDED(cs_main);
 
 /** Used by getblockstats to get feerates at different percentiles by weight  */
 void CalculatePercentilesByWeight(CAmount result[NUM_GETBLOCKSTATS_PERCENTILES], std::vector<std::pair<CAmount, int64_t>>& scores, int64_t total_weight);

test/functional/interface_rest.py

@@ -289,7 +289,7 @@ def run_test(self):
 
         # Compare with normal RPC block response
         rpc_block_json = self.nodes[0].getblock(bb_hash)
-        for key in ['hash', 'confirmations', 'height', 'version', 'merkleroot', 'time', 'nonce', 'bits', 'difficulty', 'chainwork', 'previousblockhash']:
+        for key in ['hash', 'confirmations', 'height', 'version', 'merkleroot', 'time', 'nonce', 'bits', 'target', 'difficulty', 'chainwork', 'previousblockhash']:
             assert_equal(json_obj[0][key], rpc_block_json[key])
 
         # See if we can get 5 headers in one response

test/functional/rpc_blockchain.py

@@ -31,10 +31,12 @@
     MAX_FUTURE_BLOCK_TIME,
     TIME_GENESIS_BLOCK,
     REGTEST_N_BITS,
+    REGTEST_TARGET,
     create_block,
     create_coinbase,
     create_tx_with_script,
     nbits_str,
+    target_str,
 )
 from test_framework.messages import (
     CBlockHeader,
@@ -415,6 +417,7 @@ def _test_getblockheader(self):
         assert_is_hash_string(header['previousblockhash'])
         assert_is_hash_string(header['merkleroot'])
         assert_equal(header['bits'], nbits_str(REGTEST_N_BITS))
+        assert_equal(header['target'], target_str(REGTEST_TARGET))
         assert isinstance(header['time'], int)
         assert_equal(header['mediantime'], TIME_RANGE_MTP)
         assert isinstance(header['nonce'], int)

test/functional/test_framework/blocktools.py

@@ -27,6 +27,7 @@
     hash256,
     ser_uint256,
     tx_from_hex,
+    uint256_from_compact,
     uint256_from_str,
     WITNESS_SCALE_FACTOR,
 )
@@ -66,10 +67,15 @@
 MIN_BLOCKS_TO_KEEP = 288
 
 REGTEST_N_BITS = 0x207fffff  # difficulty retargeting is disabled in REGTEST chainparams"
+REGTEST_TARGET = 0x7fffff0000000000000000000000000000000000000000000000000000000000
+assert_equal(uint256_from_compact(REGTEST_N_BITS), REGTEST_TARGET)
 
 def nbits_str(nbits):
     return f"{nbits:08x}"
 
+def target_str(target):
+    return f"{target:064x}"
+
 def create_block(hashprev=None, coinbase=None, ntime=None, *, version=None, tmpl=None, txlist=None):
     """Create a block (with regtest difficulty)."""
     block = CBlock()