rpc: Add hash_type MUHASH to gettxoutsetinfo

Also small style fix in rpc/util.cpp

src/node/coinstats.cpp

@@ -6,6 +6,7 @@
 #include <node/coinstats.h>
 
 #include <coins.h>
+#include <crypto/muhash.h>
 #include <hash.h>
 #include <serialize.h>
 #include <uint256.h>
@@ -42,8 +43,20 @@ static void ApplyHash(CCoinsStats& stats, CHashWriter& ss, const uint256& hash,
 
 static void ApplyHash(CCoinsStats& stats, std::nullptr_t, const uint256& hash, const std::map<uint32_t, Coin>& outputs, std::map<uint32_t, Coin>::const_iterator it) {}
 
+static void ApplyHash(CCoinsStats& stats, MuHash3072& muhash, const uint256& hash, const std::map<uint32_t, Coin>& outputs, std::map<uint32_t, Coin>::const_iterator it)
+{
+    COutPoint outpoint = COutPoint(hash, it->first);
+    Coin coin = it->second;
+
+    CDataStream ss(SER_DISK, PROTOCOL_VERSION);
+    ss << outpoint;
+    ss << static_cast<uint32_t>(coin.nHeight * 2 + coin.fCoinBase);
+    ss << coin.out;
+    muhash.Insert(MakeUCharSpan(ss));
+}
+
 template <typename T>
-static void ApplyStats(CCoinsStats &stats, T& hash_obj, const uint256& hash, const std::map<uint32_t, Coin>& outputs)
+static void ApplyStats(CCoinsStats& stats, T& hash_obj, const uint256& hash, const std::map<uint32_t, Coin>& outputs)
 {
     assert(!outputs.empty());
     stats.nTransactions++;
@@ -108,6 +121,10 @@ bool GetUTXOStats(CCoinsView* view, CCoinsStats& stats, CoinStatsHashType hash_t
         CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
         return GetUTXOStats(view, stats, ss, interruption_point);
     }
+    case(CoinStatsHashType::MUHASH): {
+        MuHash3072 muhash;
+        return GetUTXOStats(view, stats, muhash, interruption_point);
+    }
     case(CoinStatsHashType::NONE): {
         return GetUTXOStats(view, stats, nullptr, interruption_point);
     }
@@ -120,10 +137,18 @@ static void PrepareHash(CHashWriter& ss, const CCoinsStats& stats)
 {
     ss << stats.hashBlock;
 }
+// MuHash does not need the prepare step
+static void PrepareHash(MuHash3072& muhash, CCoinsStats& stats) {}
 static void PrepareHash(std::nullptr_t, CCoinsStats& stats) {}
 
 static void FinalizeHash(CHashWriter& ss, CCoinsStats& stats)
 {
     stats.hashSerialized = ss.GetHash();
 }
+static void FinalizeHash(MuHash3072& muhash, CCoinsStats& stats)
+{
+    uint256 out;
+    muhash.Finalize(out);
+    stats.hashSerialized = out;
+}
 static void FinalizeHash(std::nullptr_t, CCoinsStats& stats) {}

src/node/coinstats.h

@@ -16,6 +16,7 @@ class CCoinsView;
 
 enum class CoinStatsHashType {
     HASH_SERIALIZED,
+    MUHASH,
     NONE,
 };
 

src/rpc/blockchain.cpp

@@ -1047,13 +1047,26 @@ static RPCHelpMan pruneblockchain()
     };
 }
 
+CoinStatsHashType ParseHashType(const std::string& hash_type_input)
+{
+    if (hash_type_input == "hash_serialized_2") {
+        return CoinStatsHashType::HASH_SERIALIZED;
+    } else if (hash_type_input == "muhash") {
+        return CoinStatsHashType::MUHASH;
+    } else if (hash_type_input == "none") {
+        return CoinStatsHashType::NONE;
+    } else {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s is not a valid hash_type", hash_type_input));
+    }
+}
+
 static RPCHelpMan gettxoutsetinfo()
 {
     return RPCHelpMan{"gettxoutsetinfo",
                 "\nReturns statistics about the unspent transaction output set.\n"
                 "Note this call may take some time.\n",
                 {
-                    {"hash_type", RPCArg::Type::STR, /* default */ "hash_serialized_2", "Which UTXO set hash should be calculated. Options: 'hash_serialized_2' (the legacy algorithm), 'none'."},
+                    {"hash_type", RPCArg::Type::STR, /* default */ "hash_serialized_2", "Which UTXO set hash should be calculated. Options: 'hash_serialized_2' (the legacy algorithm), 'muhash', 'none'."},
                 },
                 RPCResult{
                     RPCResult::Type::OBJ, "", "",
@@ -1063,7 +1076,8 @@ static RPCHelpMan gettxoutsetinfo()
                         {RPCResult::Type::NUM, "transactions", "The number of transactions with unspent outputs"},
                         {RPCResult::Type::NUM, "txouts", "The number of unspent transaction outputs"},
                         {RPCResult::Type::NUM, "bogosize", "A meaningless metric for UTXO set size"},
-                        {RPCResult::Type::STR_HEX, "hash_serialized_2", "The serialized hash (only present if 'hash_serialized_2' hash_type is chosen)"},
+                        {RPCResult::Type::STR_HEX, "hash_serialized_2", /* optional */ true, "The serialized hash (only present if 'hash_serialized_2' hash_type is chosen)"},
+                        {RPCResult::Type::STR_HEX, "muhash", /* optional */ true, "The serialized hash (only present if 'muhash' hash_type is chosen)"},
                         {RPCResult::Type::NUM, "disk_size", "The estimated size of the chainstate on disk"},
                         {RPCResult::Type::STR_AMOUNT, "total_amount", "The total amount"},
                     }},
@@ -1078,7 +1092,7 @@ static RPCHelpMan gettxoutsetinfo()
     CCoinsStats stats;
     ::ChainstateActive().ForceFlushStateToDisk();
 
-    const CoinStatsHashType hash_type = ParseHashType(request.params[0], CoinStatsHashType::HASH_SERIALIZED);
+    const CoinStatsHashType hash_type{request.params[0].isNull() ? CoinStatsHashType::HASH_SERIALIZED : ParseHashType(request.params[0].get_str())};
 
     CCoinsView* coins_view = WITH_LOCK(cs_main, return &ChainstateActive().CoinsDB());
     NodeContext& node = EnsureNodeContext(request.context);
@@ -1091,6 +1105,9 @@ static RPCHelpMan gettxoutsetinfo()
         if (hash_type == CoinStatsHashType::HASH_SERIALIZED) {
             ret.pushKV("hash_serialized_2", stats.hashSerialized.GetHex());
         }
+        if (hash_type == CoinStatsHashType::MUHASH) {
+              ret.pushKV("muhash", stats.hashSerialized.GetHex());
+        }
         ret.pushKV("disk_size", stats.nDiskSize);
         ret.pushKV("total_amount", ValueFromAmount(stats.nTotalAmount));
     } else {

src/rpc/util.cpp

@@ -113,23 +113,6 @@ std::vector<unsigned char> ParseHexO(const UniValue& o, std::string strKey)
     return ParseHexV(find_value(o, strKey), strKey);
 }
 
-CoinStatsHashType ParseHashType(const UniValue& param, const CoinStatsHashType default_type)
-{
-    if (param.isNull()) {
-        return default_type;
-    } else {
-        std::string hash_type_input = param.get_str();
-
-        if (hash_type_input == "hash_serialized_2") {
-            return CoinStatsHashType::HASH_SERIALIZED;
-        } else if (hash_type_input == "none") {
-            return CoinStatsHashType::NONE;
-        } else {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%d is not a valid hash_type", hash_type_input));
-        }
-    }
-}
-
 std::string HelpExampleCli(const std::string& methodname, const std::string& args)
 {
     return "> bitcoin-cli " + methodname + " " + args + "\n";

src/rpc/util.h

@@ -77,8 +77,6 @@ extern uint256 ParseHashO(const UniValue& o, std::string strKey);
 extern std::vector<unsigned char> ParseHexV(const UniValue& v, std::string strName);
 extern std::vector<unsigned char> ParseHexO(const UniValue& o, std::string strKey);
 
-CoinStatsHashType ParseHashType(const UniValue& param, const CoinStatsHashType default_type);
-
 extern CAmount AmountFromValue(const UniValue& value);
 extern std::string HelpExampleCli(const std::string& methodname, const std::string& args);
 extern std::string HelpExampleRpc(const std::string& methodname, const std::string& args);

test/functional/rpc_blockchain.py

@@ -268,6 +268,18 @@ def _test_gettxoutsetinfo(self):
         res5 = node.gettxoutsetinfo(hash_type='none')
         assert 'hash_serialized_2' not in res5
 
+        # hash_type muhash should return a different UTXO set hash.
+        res6 = node.gettxoutsetinfo(hash_type='muhash')
+        assert 'muhash' in res6
+        assert(res['hash_serialized_2'] != res6['muhash'])
+
+        # muhash should not be included in gettxoutset unless requested.
+        for r in [res, res2, res3, res4, res5]:
+            assert 'muhash' not in r
+
+        # Unknown hash_type raises an error
+        assert_raises_rpc_error(-8, "foohash is not a valid hash_type", node.gettxoutsetinfo, "foohash")
+
     def _test_getblockheader(self):
         node = self.nodes[0]