Add -datacarriercost option to adjust policy vsize of datacarrier bytes

Author: luke-jr

src/init.cpp

@@ -645,6 +645,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-bytespersigop", strprintf("Equivalent bytes per sigop in transactions for relay and mining (default: %u)", DEFAULT_BYTES_PER_SIGOP), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-bytespersigopstrict", strprintf("Minimum bytes per sigop in transactions we relay and mine (default: %u)", DEFAULT_BYTES_PER_SIGOP_STRICT), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarrier", strprintf("Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-datacarriercost", strprintf("Treat extra data in transactions as at least N vbytes per actual byte (default: %s)", DEFAULT_WEIGHT_PER_DATA_BYTE / 4.0), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarrierfullcount", strprintf("Apply datacarriersize limit to all known datacarrier methods (default: %u)", DEFAULT_DATACARRIER_FULLCOUNT), ArgsManager::ALLOW_ANY | (DEFAULT_DATACARRIER_FULLCOUNT ? uint32_t{ArgsManager::DEBUG_ONLY} : 0), OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarriersize",
                    strprintf("Maximum size of data in data carrier transactions we relay and mine, in bytes (default: %u)",
@@ -1040,6 +1041,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         }
     }
 
+    if (auto parsed = args.GetFixedPointArg("-datacarriercost", 2)) {
+        g_weight_per_data_byte = ((*parsed * WITNESS_SCALE_FACTOR) + 99) / 100;
+    }
+
     nBytesPerSigOp = args.GetIntArg("-bytespersigop", nBytesPerSigOp);
     nBytesPerSigOpStrict = args.GetIntArg("-bytespersigopstrict", nBytesPerSigOpStrict);
 

src/policy/policy.h

@@ -48,6 +48,8 @@ static constexpr unsigned int DEFAULT_INCREMENTAL_RELAY_FEE{1000};
 static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP{20};
 /** Default for -bytespersigopstrict */
 static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP_STRICT{20};
+/** Default for -datacarriercost (multiplied by WITNESS_SCALE_FACTOR) */
+static constexpr unsigned int DEFAULT_WEIGHT_PER_DATA_BYTE{1};
 /** Default for -permitbarepubkey */
 static constexpr bool DEFAULT_PERMIT_BAREPUBKEY{true};
 /** Default for -permitbaremultisig */

src/policy/settings.cpp

@@ -9,3 +9,4 @@
 
 unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;
 unsigned int nBytesPerSigOpStrict = DEFAULT_BYTES_PER_SIGOP_STRICT;
+unsigned int g_weight_per_data_byte = DEFAULT_WEIGHT_PER_DATA_BYTE;

src/policy/settings.h

@@ -8,5 +8,6 @@
 
 extern unsigned int nBytesPerSigOp;
 extern unsigned int nBytesPerSigOpStrict;
+extern unsigned int g_weight_per_data_byte;
 
 #endif // BITCOIN_POLICY_SETTINGS_H