Adapted Blockchain.java to use lookup table for name registration fees, to more easily support fee adjustments.

This is currently for name registration transactions only, but can be adapted (or duplicated) for other transaction types when needed.

Note: this switches from a greater-than (>) to a greater-than-or-equal (>=) timestamp comparison, as it makes more sense this way. It shouldn't affect the previous transition since there were no REGISTER_NAME transactions at that exact timestamp.

src/main/java/org/qortal/block/BlockChain.java

@@ -73,9 +73,13 @@ public class BlockChain {
 	}
 
 	// Custom transaction fees
-	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
-	private long nameRegistrationUnitFee;
-	private long nameRegistrationUnitFeeTimestamp;
+	/** Unit fees by transaction timestamp */
+	public static class UnitFeesByTimestamp {
+		public long timestamp;
+		@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+		public long fee;
+	}
+	private List<UnitFeesByTimestamp> nameRegistrationUnitFees;
 
 	/** Map of which blockchain features are enabled when (height/timestamp) */
 	@XmlJavaTypeAdapter(StringLongMapXmlAdapter.class)
@@ -306,16 +310,6 @@ public class BlockChain {
 		return this.maxBlockSize;
 	}
 
-	// Custom transaction fees
-	public long getNameRegistrationUnitFee() {
-		return this.nameRegistrationUnitFee;
-	}
-
-	public long getNameRegistrationUnitFeeTimestamp() {
-		// FUTURE: we could use a separate structure to indicate fee adjustments for different transaction types
-		return this.nameRegistrationUnitFeeTimestamp;
-	}
-
 	/** Returns true if approval-needing transaction types require a txGroupId other than NO_GROUP. */
 	public boolean getRequireGroupForApproval() {
 		return this.requireGroupForApproval;
@@ -430,6 +424,16 @@ public class BlockChain {
 		throw new IllegalStateException(String.format("No block timing info available for height %d", ourHeight));
 	}
 
+	public long getNameRegistrationUnitFeeAtTimestamp(long ourTimestamp) {
+		// Scan through for reward at our height
+		for (int i = 0; i < nameRegistrationUnitFees.size(); ++i)
+			if (ourTimestamp >= nameRegistrationUnitFees.get(i).timestamp)
+				return nameRegistrationUnitFees.get(i).fee;
+
+		// Default to system-wide unit fee
+		return this.getUnitFee();
+	}
+
 	/** Validate blockchain config read from JSON */
 	private void validateConfig() {
 		if (this.genesisInfo == null)

src/main/java/org/qortal/transaction/RegisterNameTransaction.java

@@ -39,11 +39,7 @@ public class RegisterNameTransaction extends Transaction {
 
 	@Override
 	public long getUnitFee(Long timestamp) {
-		// Use a higher unit fee after the fee increase timestamp
-		if (timestamp > BlockChain.getInstance().getNameRegistrationUnitFeeTimestamp()) {
-			return BlockChain.getInstance().getNameRegistrationUnitFee();
-		}
-		return BlockChain.getInstance().getUnitFee();
+		return BlockChain.getInstance().getNameRegistrationUnitFeeAtTimestamp(timestamp);
 	}
 
 	// Navigation

src/main/resources/blockchain.json

@@ -4,8 +4,9 @@
 	"maxBlockSize": 2097152,
 	"maxBytesPerUnitFee": 1024,
 	"unitFee": "0.001",
-	"nameRegistrationUnitFee": "5",
-	"nameRegistrationUnitFeeTimestamp": 1645372800000,
+	"nameRegistrationUnitFees": [
+		{ "timestamp": 1645372800000, "fee": "5" }
+	],
 	"useBrokenMD160ForAddresses": false,
 	"requireGroupForApproval": false,
 	"defaultGroupId": 0,