Wipe unconfirmed transactions on startup

Fix issues with last reference and unconfirmed transactions.

src/main/java/api/UnmarshalListener.java

@@ -0,0 +1,18 @@
+package api;
+
+import javax.xml.bind.Unmarshaller.Listener;
+
+import data.transaction.TransactionData;
+
+public class UnmarshalListener extends Listener {
+
+	@Override
+	public void afterUnmarshal(Object target, Object parent) {
+		if (!(target instanceof TransactionData))
+			return;
+
+		// do something
+		return;
+	}
+
+}

src/main/java/api/resource/AssetsResource.java

@@ -258,7 +258,7 @@ public class AssetsResource {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
-			ValidationResult result = transaction.isValid();
+			ValidationResult result = transaction.isValidUnconfirmed();
 			if (result != ValidationResult.OK)
 				throw TransactionsResource.createTransactionInvalidException(request, result);
 

src/main/java/api/resource/NamesResource.java

@@ -65,7 +65,7 @@ public class NamesResource {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
-			ValidationResult result = transaction.isValid();
+			ValidationResult result = transaction.isValidUnconfirmed();
 			if (result != ValidationResult.OK)
 				throw TransactionsResource.createTransactionInvalidException(request, result);
 

src/main/java/api/resource/PaymentsResource.java

@@ -65,7 +65,7 @@ public class PaymentsResource {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
-			ValidationResult result = transaction.isValid();
+			ValidationResult result = transaction.isValidUnconfirmed();
 			if (result != ValidationResult.OK)
 				throw TransactionsResource.createTransactionInvalidException(request, result);
 

src/main/java/api/resource/TransactionsResource.java

@@ -319,7 +319,7 @@ public class TransactionsResource {
 			if (!transaction.isSignatureValid())
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_SIGNATURE);
 
-			ValidationResult result = transaction.isValid();
+			ValidationResult result = transaction.isValidUnconfirmed();
 			if (result != ValidationResult.OK)
 				throw createTransactionInvalidException(request, result);
 

src/main/java/data/transaction/TransactionData.java

@@ -111,6 +111,11 @@ public abstract class TransactionData {
 		return Crypto.toAddress(this.creatorPublicKey);
 	}
 
+	@XmlTransient
+	public void setCreatorPublicKey(byte[] creatorPublicKey) {
+		this.creatorPublicKey = creatorPublicKey;
+	}
+
 	// Comparison
 
 	@Override

src/main/java/qora/block/BlockGenerator.java

@@ -9,6 +9,7 @@ import org.apache.logging.log4j.Logger;
 import data.block.BlockData;
 import data.transaction.TransactionData;
 import qora.account.PrivateKeyAccount;
+import qora.account.PublicKeyAccount;
 import qora.block.Block.ValidationResult;
 import qora.transaction.Transaction;
 import repository.BlockRepository;
@@ -47,6 +48,12 @@ public class BlockGenerator extends Thread {
 		Thread.currentThread().setName("BlockGenerator");
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
+			// Wipe existing unconfirmed transactions
+			List<TransactionData> unconfirmedTransactions = repository.getTransactionRepository().getAllUnconfirmedTransactions();
+			for (TransactionData transactionData : unconfirmedTransactions)
+				repository.getTransactionRepository().delete(transactionData);
+			repository.saveChanges();
+
 			generator = new PrivateKeyAccount(repository, generatorPrivateKey);
 
 			// Going to need this a lot...
@@ -109,10 +116,10 @@ public class BlockGenerator extends Thread {
 		// Grab all unconfirmed transactions (already sorted)
 		List<TransactionData> unconfirmedTransactions = repository.getTransactionRepository().getAllUnconfirmedTransactions();
 
-		// Remove transactions that have timestamp later than block's timestamp (not yet valid)
-		unconfirmedTransactions.removeIf(transactionData -> transactionData.getTimestamp() > newBlock.getBlockData().getTimestamp());
-		// Remove transactions that have expired deadline for this block
-		unconfirmedTransactions.removeIf(transactionData -> Transaction.fromData(repository, transactionData).getDeadline() <= newBlock.getBlockData().getTimestamp());
+		unconfirmedTransactions.removeIf(transactionData -> !isSuitableTransaction(repository, transactionData, newBlock));
+
+		// Discard last-reference changes used to aid transaction validity checks
+		repository.discardChanges();
 
 		// Attempt to add transactions until block is full, or we run out
 		for (TransactionData transactionData : unconfirmedTransactions)
@@ -120,6 +127,40 @@ public class BlockGenerator extends Thread {
 				break;
 	}
 
+	/** Returns true if transaction is suitable for adding to new block */
+	private boolean isSuitableTransaction(Repository repository, TransactionData transactionData, Block newBlock) {
+		// Ignore transactions that have timestamp later than block's timestamp (not yet valid)
+		if (transactionData.getTimestamp() > newBlock.getBlockData().getTimestamp())
+			return false;
+
+		Transaction transaction = Transaction.fromData(repository, transactionData);
+
+		// Ignore transactions that have expired deadline for this block
+		if (transaction.getDeadline() <= newBlock.getBlockData().getTimestamp())
+			return false;
+
+		// Ignore transactions that are currently not valid
+		try {
+			if (transaction.isValid() != Transaction.ValidationResult.OK)
+				return false;
+		} catch (DataException e) {
+			// Not good either
+			return false;
+		}
+
+		// Good for adding to a block
+		// Temporarily update sender's last reference so that subsequent transactions validations work
+		// These updates will be discard on exit of addUnconfirmedTransactions() above
+		PublicKeyAccount creator = new PublicKeyAccount(repository, transactionData.getCreatorPublicKey());
+		try {
+			creator.setLastReference(transactionData.getSignature());
+		} catch (DataException e) {
+			// Not good
+			return false;
+		}
+		return true;
+	}
+
 	public void shutdown() {
 		this.running = false;
 		// Interrupt too, absorbed by HSQLDB but could be caught by Thread.sleep()

src/main/java/qora/transaction/IssueAssetTransaction.java

@@ -32,6 +32,10 @@ public class IssueAssetTransaction extends Transaction {
 		super(repository, transactionData);
 
 		this.issueAssetTransactionData = (IssueAssetTransactionData) this.transactionData;
+
+		// XXX This is horrible - thanks to JAXB unmarshalling not calling constructor
+		if (this.transactionData.getCreatorPublicKey() == null)
+			this.transactionData.setCreatorPublicKey(this.issueAssetTransactionData.getIssuerPublicKey());
 	}
 
 	// More information

src/main/java/qora/transaction/PaymentTransaction.java

@@ -26,6 +26,10 @@ public class PaymentTransaction extends Transaction {
 		super(repository, transactionData);
 
 		this.paymentTransactionData = (PaymentTransactionData) this.transactionData;
+
+		// XXX This is horrible - thanks to JAXB unmarshalling not calling constructor
+		if (this.transactionData.getCreatorPublicKey() == null)
+			this.transactionData.setCreatorPublicKey(this.paymentTransactionData.getSenderPublicKey());
 	}
 
 	// More information

src/main/java/qora/transaction/RegisterNameTransaction.java

@@ -28,6 +28,10 @@ public class RegisterNameTransaction extends Transaction {
 		super(repository, transactionData);
 
 		this.registerNameTransactionData = (RegisterNameTransactionData) this.transactionData;
+
+		// XXX This is horrible - thanks to JAXB unmarshalling not calling constructor
+		if (this.transactionData.getCreatorPublicKey() == null)
+			this.transactionData.setCreatorPublicKey(this.registerNameTransactionData.getRegistrantPublicKey());
 	}
 
 	// More information

src/main/java/qora/transaction/Transaction.java

@@ -410,6 +410,28 @@ public abstract class Transaction {
 		}
 	}
 
+	/**
+	 * Returns whether transaction can be added to unconfirmed transactions.
+	 * <p>
+	 * NOTE: temporarily updates creator's lastReference to that from
+	 * unconfirmed transactions, and hence calls <tt>repository.discardChanges()</tt>
+	 * before exit.
+	 * <p>
+	 * This is not done normally because we don't want unconfirmed transactions affecting validity of transactions already included in a block.
+	 * 
+	 * @return true if transaction can be added to unconfirmed transactions, false otherwise
+	 * @throws DataException
+	 */
+	public ValidationResult isValidUnconfirmed() throws DataException {
+		try {
+			Account creator = this.getCreator();
+			creator.setLastReference(creator.getUnconfirmedLastReference());
+			return this.isValid();
+		} finally {
+			repository.discardChanges();
+		}
+	}
+
 	/**
 	 * Returns whether transaction can be added to the blockchain.
 	 * <p>

src/main/java/repository/hsqldb/transaction/HSQLDBTransactionRepository.java

@@ -517,6 +517,11 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		} catch (SQLException e) {
 			throw new DataException("Unable to delete transaction from repository", e);
 		}
+		try {
+			this.repository.delete("UnconfirmedTransactions", "signature = ?", transactionData.getSignature());
+		} catch (SQLException e) {
+			throw new DataException("Unable to remove transaction from unconfirmed transactions repository", e);
+		}
 	}
 
 }

src/main/resources/i18n/ApiError_en.properties

@@ -47,6 +47,7 @@ BLOCK_NO_EXISTS=block does not exist
 # Transactions
 TRANSACTION_NO_EXISTS=transaction does not exist
 PUBLIC_KEY_NOT_FOUND=public key not found
+TRANSACTION_INVALID=transaction invalid
 
 # Names
 NAME_NO_EXISTS=name does not exist