[refactor] add helper to apply ArgsManager to BlockAssembler::Options

This allows us to both manually manipulate options and grab values from
ArgsManager (i.e. -blockmaxweight and -blockmintxfee config options)
when constructing BlockAssembler::Options. Prior to this change, the
only way to apply the config options is by ctoring BlockAssembler with
no options, which calls DefaultOptions().

Author: glozow

src/node/miner.cpp

@@ -72,23 +72,27 @@ BlockAssembler::BlockAssembler(Chainstate& chainstate, const CTxMemPool* mempool
     nBlockMaxWeight = std::max<size_t>(4000, std::min<size_t>(MAX_BLOCK_WEIGHT - 4000, options.nBlockMaxWeight));
 }
 
-static BlockAssembler::Options DefaultOptions()
+void ApplyArgsManOptions(const ArgsManager& gArgs, BlockAssembler::Options& options)
 {
     // Block resource limits
     // If -blockmaxweight is not given, limit to DEFAULT_BLOCK_MAX_WEIGHT
-    BlockAssembler::Options options;
     options.nBlockMaxWeight = gArgs.GetIntArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
     if (gArgs.IsArgSet("-blockmintxfee")) {
         std::optional<CAmount> parsed = ParseMoney(gArgs.GetArg("-blockmintxfee", ""));
         options.blockMinFeeRate = CFeeRate{parsed.value_or(DEFAULT_BLOCK_MIN_TX_FEE)};
     } else {
         options.blockMinFeeRate = CFeeRate{DEFAULT_BLOCK_MIN_TX_FEE};
     }
+}
+static BlockAssembler::Options ConfiguredOptions()
+{
+    BlockAssembler::Options options;
+    ApplyArgsManOptions(gArgs, options);
     return options;
 }
 
 BlockAssembler::BlockAssembler(Chainstate& chainstate, const CTxMemPool* mempool)
-    : BlockAssembler(chainstate, mempool, DefaultOptions()) {}
+    : BlockAssembler(chainstate, mempool, ConfiguredOptions()) {}
 
 void BlockAssembler::resetBlock()
 {

src/node/miner.h

@@ -16,6 +16,7 @@
 #include <boost/multi_index/ordered_index.hpp>
 #include <boost/multi_index_container.hpp>
 
+class ArgsManager;
 class ChainstateManager;
 class CBlockIndex;
 class CChainParams;
@@ -197,6 +198,9 @@ int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParam
 
 /** Update an old GenerateCoinbaseCommitment from CreateNewBlock after the block txs have changed */
 void RegenerateCommitments(CBlock& block, ChainstateManager& chainman);
+
+/** Apply -blockmintxfee and -blockmaxweight options from ArgsManager to BlockAssembler options. */
+void ApplyArgsManOptions(const ArgsManager& gArgs, BlockAssembler::Options& options);
 } // namespace node
 
 #endif // BITCOIN_NODE_MINER_H