Merge #19145: Add hash_type MUHASH for gettxoutsetinfo

e987ae5a554c9952812746c29f2766bacea4b727 test: Add test for deterministic UTXO set hash results (Fabian Jahr)
6ccc8fc067bf516cda7bc5d7d721945be5ac2003 test: Add test for gettxoutsetinfo RPC with MuHash (Fabian Jahr)
0d3b2f643d7da3202c0a0e757539208c4aa7c450 rpc: Add hash_type MUHASH to gettxoutsetinfo (Fabian Jahr)
2474645f3b15687e7f196b89eb935d6e6a98a9da refactor: Separate hash and stats calculation in coinstats (Fabian Jahr)
a1fcceac69097a8e6540a6fd8121a5d53022528f refactor: Improve encapsulation between MuHash3072 and Num3072 (Fabian Jahr)

Pull request description:

  This is another Pr in the series PRs for Coinstatsindex (see overview in #18000). This PR adds the `hash_type` option `muhash` to `gettxoutsetinfo` through which the user can calculate the serialized muhash of the utxo set. This PR does not use the index yet.

ACKs for top commit:
  Sjors:
    tACK e987ae5
  achow101:
    ACK e987ae5a554c9952812746c29f2766bacea4b727
  jonatack:
    Tested re-ACK e987ae5a554c9952812746c29f2766bacea4b727 per `git diff 3506d90 e987ae5`, reviewed diff, debug built, ran gettxoutsetinfo -signet and help on this branch vs master, at height 23127 both returned `hash_serialized_2` of `2b72d65f3b6efb2311f58374ea2b939abf49684d44f4bafda45faa3b5452a454` and this branch returned `muhash` of `c9f1ff12d345ccf9939c6bbf087e6f7399b6115adee1569287e9c5c43dbb475c`
  ryanofsky:
    Code review ACK e987ae5a554c9952812746c29f2766bacea4b727. Looks very good. I left one suggestion to simplify code, but feel free to ignore it here and maybe consider it for later since PR has already had a lot of review.

Tree-SHA512: 9a739ce375e73749fa69a467262b60d3e5314ef384e2d7150b3bbc8e4125cd9fd1db95306623bb9a632fcbaf5d9d2bf2f5cc43bf717d4ff5e2c9c4b52dd9296c

1 files changed, 20 insertions, 3 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 6e2a7c330e..5be02b1e4e 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1026,13 +1026,26 @@ 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, "", "",
@@ -1042,7 +1055,8 @@ 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"},
                     }},
@@ -1057,7 +1071,7 @@ 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);
@@ -1070,6 +1084,9 @@ 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 {