Skeleton, for comments.

src/TransactionEngine.h

@@ -0,0 +1,53 @@
+#ifndef __TRANSACTIONENGINE__
+#define __TRANSACTIONENGINE__
+
+#include "Ledger.h"
+#include "SerializedTransaction.h"
+
+// A TransactionEngine applies serialized transactions to a ledger
+// It can also, verify signatures, verify fees, and give rejection reasons
+
+enum TransactionEngineResult
+{ // <0 = Can never succeed, 0 = success, >0 = failed, but could succeed
+	terUNKNOWN     = -3,	// The transactions requires logic not implemented yet
+	terINSUF_FEE_P = -2,	// fee totally insufficient
+	terINVALID     = -1,	// The transaction is ill-formed
+	terSUCCESS     = 0,		// The transaction was applied
+	terALREADY,				// The transaction was already in the ledger
+	terINSUF_FEE_T,			// fee insufficient now (account doesn't exist, network load)
+	terUNFUNDED,			// Source account had insufficient balance
+	terNO_PATH,				// No path existed or met transaction/balance requirements
+	terPAST_SEQ,			// This sequence number has already past
+	terPRE_SEQ,				// Missing/inapplicable prior transaction
+	terPAST_LEDGER,			// The transaction expired and can't be applied
+};
+
+enum TransactionEngineParams
+{
+	tepNO_CHECK_SIGN = 1,	// Signature already checked
+	tepNO_CHECK_FEE  = 2,	// It was voted into a ledger anyway
+};
+
+class TransactionEngine
+{
+protected:
+	Ledger::pointer mTargetLedger;
+
+	TransactionEngineResult doPayment(const SerializedTransaction&);
+	TransactionEngineResult doInvoice(const SerializedTransaction&);
+	TransactionEngineResult doOffer(const SerializedTransaction&);
+	TransactionEngineResult doTake(const SerializedTransaction&);
+	TransactionEngineResult doCancel(const SerializedTransaction&);
+	TransactionEngineResult doStore(const SerializedTransaction&);
+	TransactionEngineResult doDelete(const SerializedTransaction&);
+
+public:
+	TransactionEngine(Ledger::pointer targetLedger) : mTargetLedger(targetLedger) { ; }
+
+	Ledger::pointer getTargetLedger() { return mTargetLedger; }
+	void setTargetLedger(Ledger::pointer targetLedger) { mTargetLedger = targetLedger; }
+
+	TransactionEngineResult applyTransaction(const SerializedTransaction&, TransactionEngineParams);
+};
+
+#endif