GetCoinAge
[NovacoinLibrary.git] / Novacoin / CTransaction.cs
index ef444f2..e0630aa 100644 (file)
@@ -20,6 +20,8 @@ using System;
 using System.Text;
 using System.Collections.Generic;
 using System.IO;
+using System.Diagnostics.Contracts;
+using System.Numerics;
 
 namespace Novacoin
 {
@@ -42,19 +44,41 @@ namespace Novacoin
     }
 
     /// <summary>
-    /// Represents the transaction. Any transaction must provide one input and one output at least.
+    /// Represents the transaction.
     /// </summary>
     public class CTransaction
     {
         /// <summary>
+        /// One cent = 10000 satoshis.
+        /// </summary>
+        public const ulong nCent = 10000;
+
+        /// <summary>
         /// One coin = 1000000 satoshis.
         /// </summary>
         public const ulong nCoin = 1000000;
+        
         /// <summary>
         /// Sanity checking threshold.
         /// </summary>
         public const ulong nMaxMoney = 2000000000 * nCoin;
 
+        public const ulong nMinTxFee = nCent / 10;
+        public const ulong nMinRelayTxFee = nCent / 50;
+        public const ulong nMinTxoutAmount = nCent / 100;        
+
+        /// <summary>
+        /// Maximum transaction size is 250Kb
+        /// </summary>
+        public const uint nMaxTxSize = 250000;
+
+        public enum MinFeeMode
+        {
+            GMF_BLOCK,
+            GMF_RELAY,
+            GMF_SEND,
+        }
+
         /// <summary>
         /// Version of transaction schema.
         /// </summary>
@@ -132,15 +156,15 @@ namespace Novacoin
                 return true;
             }
 
-            CTransaction txPrev = null;
+            TxOutItem txOutCursor = null;
             for (int i = 0; i < vin.Length; i++)
             {
                 var outpoint = vin[i].prevout;
 
-                if (!CBlockStore.Instance.GetTransaction(outpoint.hash, ref txPrev))
+                if (!CBlockStore.Instance.GetTxOutCursor(outpoint, ref txOutCursor))
                     return false;
 
-                if (!ScriptCode.VerifyScript(vin[i].scriptSig, txPrev.vout[outpoint.n].scriptPubKey, this, i, (int)scriptflag.SCRIPT_VERIFY_P2SH, 0))
+                if (!ScriptCode.VerifyScript(vin[i].scriptSig, txOutCursor.scriptPubKey, this, i, (int)scriptflag.SCRIPT_VERIFY_P2SH, 0))
                     return false;
             }
 
@@ -174,7 +198,7 @@ namespace Novacoin
         /// <returns>Checking result</returns>
         public bool CheckTransaction()
         {
-            if (Size > 250000 || vin.Length == 0 || vout.Length == 0)
+            if (Size > nMaxTxSize || vin.Length == 0 || vout.Length == 0)
             {
                 return false;
             }
@@ -245,9 +269,9 @@ namespace Novacoin
             }
             if (nBlockTime == 0)
             {
-                nBlockTime = NetUtils.GetAdjustedTime();
+                nBlockTime = NetInfo.GetAdjustedTime();
             }
-            if (nLockTime < (nLockTime < NetUtils.nLockTimeThreshold ? nBlockHeight : nBlockTime))
+            if (nLockTime < (nLockTime < NetInfo.nLockTimeThreshold ? nBlockHeight : nBlockTime))
             {
                 return true;
             }
@@ -260,7 +284,7 @@ namespace Novacoin
             }
             return true;
         }
-        
+
         /// <summary>
         /// Parse byte sequence and initialize new instance of CTransaction
         /// </summary>
@@ -315,11 +339,11 @@ namespace Novacoin
         /// <summary>
         /// Serialized size
         /// </summary>
-        public int Size
+        public uint Size
         {
             get
             {
-                int nSize = 12; // nVersion, nTime, nLockLime
+                uint nSize = 12; // nVersion, nTime, nLockLime
 
                 nSize += VarInt.GetEncodedSize(vin.Length);
                 nSize += VarInt.GetEncodedSize(vout.Length);
@@ -393,9 +417,26 @@ namespace Novacoin
         /// <summary>
         /// Transaction hash
         /// </summary>
-        public Hash256 Hash
+        public uint256 Hash
         {
-            get { return Hash256.Compute256(this); }
+            get { return CryptoUtils.ComputeHash256(this); }
+        }
+
+        /// <summary>
+        /// Amount of novacoins spent by this transaction.
+        /// </summary>
+        public ulong nValueOut
+        {
+            get
+            {
+                ulong nValueOut = 0;
+                foreach (var txout in vout)
+                {
+                    nValueOut += txout.nValue;
+                    Contract.Assert(MoneyRange(txout.nValue) && MoneyRange(nValueOut));
+                }
+                return nValueOut;
+            }
         }
 
         /// <summary>
@@ -437,12 +478,12 @@ namespace Novacoin
 
             foreach (var txin in vin)
             {
-                sb.AppendFormat(" {0},\n", txin.ToString());
+                sb.AppendFormat(" {0},\n", txin);
             }
 
             foreach (var txout in vout)
             {
-                sb.AppendFormat(" {0},\n", txout.ToString());
+                sb.AppendFormat(" {0},\n", txout);
             }
 
             sb.AppendFormat("\nnLockTime={0}\n)", nLockTime);
@@ -451,5 +492,196 @@ namespace Novacoin
         }
 
         public static bool MoneyRange(ulong nValue) { return (nValue <= nMaxMoney); }
+
+        /// <summary>
+        /// Get total sigops.
+        /// </summary>
+        /// <param name="inputs">Inputs map.</param>
+        /// <returns>Amount of sigops.</returns>
+        public uint GetP2SHSigOpCount(ref Dictionary<COutPoint, TxOutItem> inputs)
+        {
+            if (IsCoinBase)
+            {
+                return 0;
+            }
+
+            uint nSigOps = 0;
+            for (var i = 0; i < vin.Length; i++)
+            {
+                var prevout = GetOutputFor(vin[i], ref inputs);
+                if (prevout.scriptPubKey.IsPayToScriptHash)
+                {
+                    nSigOps += prevout.scriptPubKey.GetSigOpCount(vin[i].scriptSig);
+                }
+            }
+
+            return nSigOps;
+        }
+
+        /// <summary>
+        /// Get sum of inputs spent by this transaction.
+        /// </summary>
+        /// <param name="inputs">Reference to innputs map.</param>
+        /// <returns>Sum of inputs.</returns>
+        public ulong GetValueIn(ref Dictionary<COutPoint, TxOutItem> inputs)
+        {
+            if (IsCoinBase)
+            {
+                return 0;
+            }
+
+            ulong nResult = 0;
+            for (int i = 0; i < vin.Length; i++)
+            {
+                nResult += GetOutputFor(vin[i], ref inputs).nValue;
+            }
+
+            return nResult;
+        }
+
+        /// <summary>
+        /// Helper method to find output in the map.
+        /// </summary>
+        /// <param name="input">Transaction input.</param>
+        /// <param name="inputs">eference to inuts map.</param>
+        /// <returns>Parent output.</returns>
+        private CTxOut GetOutputFor(CTxIn input, ref Dictionary<COutPoint, TxOutItem> inputs)
+        {
+            if (!inputs.ContainsKey(input.prevout))
+            {
+                throw new Exception("No such input");
+            }
+
+            var outItem = inputs[input.prevout];
+
+            return new CTxOut(outItem.nValue, outItem.scriptPubKey);
+        }
+
+        /// <summary>
+        /// Calculate coin*age. 
+        /// 
+        /// Note, only those coins meeting minimum age requirement counts.
+        /// </summary>
+        /// <param name="inputs">Inputs set.</param>
+        /// <param name="nCoinAge">Coin age calculation result.</param>
+        /// <returns>Result</returns>
+        public bool GetCoinAge(ref Dictionary<COutPoint, TxOutItem> inputs, out ulong nCoinAge)
+        {
+            BigInteger bnCentSecond = 0;  // coin age in the unit of cent-seconds
+            nCoinAge = 0;
+
+            if (IsCoinBase)
+            {
+                // Nothing spent by coinbase, coinage is always zero.
+                return true;
+            }
+
+            for( var i = 0; i<vin.Length; i++)
+            {
+                var prevout = vin[i].prevout;
+                Contract.Assert(inputs.ContainsKey(prevout));
+                var input = inputs[prevout];
+
+                CBlockStoreItem parentBlockCursor;
+                var merkleItem = CBlockStore.Instance.GetMerkleCursor(input, out parentBlockCursor);
+
+                if (merkleItem == null)
+                {
+                    return false; // Unable to find merkle node
+                }
+
+                if (nTime < merkleItem.nTime)
+                {
+                    return false;  // Transaction timestamp violation
+                }
+
+                if (parentBlockCursor.nTime + StakeModifier.nStakeMinAge > nTime)
+                {
+                    continue; // only count coins meeting min age requirement
+                }
+
+                ulong nValueIn = input.nValue;
+                bnCentSecond += new BigInteger(nValueIn) * (nTime - merkleItem.nTime) / nCent;
+            }
+
+            BigInteger bnCoinDay = bnCentSecond * nCent / nCoin / (24 * 60 * 60);
+            nCoinAge = (ulong)bnCoinDay;
+
+            return true;
+        }
+
+        public ulong GetMinFee(uint nBlockSize, bool fAllowFree, MinFeeMode mode)
+        {
+            ulong nMinTxFee = CTransaction.nMinTxFee, nMinRelayTxFee = CTransaction.nMinRelayTxFee;
+            uint nBytes = Size;
+
+            if (IsCoinStake)
+            {
+                // Enforce 0.01 as minimum fee for old approach or coinstake
+                nMinTxFee = nCent;
+                nMinRelayTxFee = nCent;
+
+                if (nTime < NetInfo.nStakeValidationSwitchTime)
+                {
+                    // Enforce zero size for compatibility with old blocks.
+                    nBytes = 0;
+                }
+            }
+
+            // Base fee is either nMinTxFee or nMinRelayTxFee
+            ulong nBaseFee = (mode == MinFeeMode.GMF_RELAY) ? nMinRelayTxFee : nMinTxFee;
+
+            uint nNewBlockSize = nBlockSize + nBytes;
+            ulong nMinFee = (1 + (ulong)nBytes / 1000) * nBaseFee;
+
+            if (fAllowFree)
+            {
+                if (nBlockSize == 1)
+                {
+                    // Transactions under 1K are free
+                    if (nBytes < 1000)
+                        nMinFee = 0;
+                }
+                else
+                {
+                    // Free transaction area
+                    if (nNewBlockSize < 27000)
+                        nMinFee = 0;
+                }
+            }
+
+            // To limit dust spam, require additional MIN_TX_FEE/MIN_RELAY_TX_FEE for
+            //    each non empty output which is less than 0.01
+            //
+            // It's safe to ignore empty outputs here, because these inputs are allowed
+            //     only for coinbase and coinstake transactions.
+            foreach (var txout in vout)
+            {
+                if (txout.nValue < nCent && !txout.IsEmpty)
+                {
+                    nMinFee += nBaseFee;
+                }
+            }
+
+            var nMaxBlockSizeGen = CBlock.nMaxBlockSize / 2;
+
+            // Raise the price as the block approaches full
+            if (nBlockSize != 1 && nNewBlockSize >= nMaxBlockSizeGen / 2)
+            {
+                if (nNewBlockSize >= nMaxBlockSizeGen)
+                {
+                    return nMaxMoney;
+                }
+
+                nMinFee *= nMaxBlockSizeGen / (nMaxBlockSizeGen - nNewBlockSize);
+            }
+
+            if (!MoneyRange(nMinFee))
+            {
+                nMinFee = nMaxMoney;
+            }
+
+            return nMinFee;
+        }
     }
 }