mining: parse block creation args in mining_args

Move the argument parsing for -blockmaxweight, -blockreservedweight,
-blockmintxfee out of init.cpp to a dedicated mining_args.cpp.

This is mostly a refactor and keeps the existing validation checks. It
does switch the weight arguments to GetArg<uint64_t>, introduced in
bitcoin/bitcoin#34582, so very large or negative weight values can be
reported differently in error messages.

src/CMakeLists.txt

@@ -232,6 +232,7 @@ add_library(bitcoin_node STATIC EXCLUDE_FROM_ALL
   node/mempool_persist.cpp
   node/mempool_persist_args.cpp
   node/miner.cpp
+  node/mining_args.cpp
   node/mini_miner.cpp
   node/minisketchwrapper.cpp
   node/peerman_args.cpp

src/init.cpp

@@ -58,6 +58,7 @@
 #include <node/mempool_persist.h>
 #include <node/mempool_persist_args.h>
 #include <node/miner.h>
+#include <node/mining_args.h>
 #include <node/peerman_args.h>
 #include <policy/feerate.h>
 #include <policy/fees/block_policy_estimator.h>
@@ -124,7 +125,6 @@
 #include <node/data/ip_asn.dat.h>
 #endif
 
-using common::AmountErrMsg;
 using common::InvalidPortErrMsg;
 using common::ResolveErrMsg;
 
@@ -1074,27 +1074,9 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         return InitError(Untranslated("peertimeout must be a positive integer."));
     }
 
-    if (const auto arg{args.GetArg("-blockmintxfee")}) {
-        if (!ParseMoney(*arg)) {
-            return InitError(AmountErrMsg("blockmintxfee", *arg));
-        }
-    }
-
-    {
-        const auto max_block_weight = args.GetIntArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
-        if (max_block_weight > MAX_BLOCK_WEIGHT) {
-            return InitError(strprintf(_("Specified -blockmaxweight (%d) exceeds consensus maximum block weight (%d)"), max_block_weight, MAX_BLOCK_WEIGHT));
-        }
-    }
-
-    {
-        const auto block_reserved_weight = args.GetIntArg("-blockreservedweight", DEFAULT_BLOCK_RESERVED_WEIGHT);
-        if (block_reserved_weight > MAX_BLOCK_WEIGHT) {
-            return InitError(strprintf(_("Specified -blockreservedweight (%d) exceeds consensus maximum block weight (%d)"), block_reserved_weight, MAX_BLOCK_WEIGHT));
-        }
-        if (block_reserved_weight < MINIMUM_BLOCK_RESERVED_WEIGHT) {
-            return InitError(strprintf(_("Specified -blockreservedweight (%d) is lower than minimum safety value of (%d)"), block_reserved_weight, MINIMUM_BLOCK_RESERVED_WEIGHT));
-        }
+    auto mining_result{node::ReadMiningArgs(args)};
+    if (!mining_result) {
+        return InitError(util::ErrorString(mining_result));
     }
 
     nBytesPerSigOp = args.GetIntArg("-bytespersigop", nBytesPerSigOp);

src/node/mining_args.cpp

@@ -0,0 +1,47 @@
+// Copyright (c) The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <node/mining_args.h>
+
+#include <common/args.h>
+#include <common/messages.h>
+#include <consensus/consensus.h>
+#include <node/mining_types.h>
+#include <tinyformat.h>
+#include <util/moneystr.h>
+#include <util/translation.h>
+
+#include <cstdint>
+
+using common::AmountErrMsg;
+using util::Error;
+using util::Result;
+
+namespace node {
+
+Result<void> ReadMiningArgs(const ArgsManager& args)
+{
+    if (const auto arg{args.GetArg("-blockmintxfee")}) {
+        if (!ParseMoney(*arg)) {
+            return Error{AmountErrMsg("blockmintxfee", *arg)};
+        }
+    }
+
+    const uint64_t max_block_weight{args.GetArg<uint64_t>("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT)};
+    if (max_block_weight > MAX_BLOCK_WEIGHT) {
+        return Error{strprintf(_("Specified -blockmaxweight (%d) exceeds consensus maximum block weight (%d)"), max_block_weight, MAX_BLOCK_WEIGHT)};
+    }
+
+    const uint64_t block_reserved_weight{args.GetArg<uint64_t>("-blockreservedweight", DEFAULT_BLOCK_RESERVED_WEIGHT)};
+    if (block_reserved_weight > MAX_BLOCK_WEIGHT) {
+        return Error{strprintf(_("Specified -blockreservedweight (%d) exceeds consensus maximum block weight (%d)"), block_reserved_weight, MAX_BLOCK_WEIGHT)};
+    }
+    if (block_reserved_weight < MINIMUM_BLOCK_RESERVED_WEIGHT) {
+        return Error{strprintf(_("Specified -blockreservedweight (%d) is lower than minimum safety value of (%d)"), block_reserved_weight, MINIMUM_BLOCK_RESERVED_WEIGHT)};
+    }
+
+    return {};
+}
+
+} // namespace node

src/node/mining_args.h

@@ -0,0 +1,18 @@
+// Copyright (c) The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_NODE_MINING_ARGS_H
+#define BITCOIN_NODE_MINING_ARGS_H
+
+#include <util/result.h>
+
+class ArgsManager;
+
+namespace node {
+
+[[nodiscard]] util::Result<void> ReadMiningArgs(const ArgsManager& args);
+
+} // namespace node
+
+#endif // BITCOIN_NODE_MINING_ARGS_H