-\feffusing System;
+\feff/**
+ * Novacoin classes library
+ * Copyright (C) 2015 Alex D. (balthazar.ad@gmail.com)
+
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using System;
using System.Text;
using System.Collections.Generic;
+using System.IO;
+using System.Diagnostics.Contracts;
+using System.Numerics;
namespace Novacoin
{
+ [Serializable]
+ public class TransactionConstructorException : Exception
+ {
+ public TransactionConstructorException()
+ {
+ }
+
+ public TransactionConstructorException(string message)
+ : base(message)
+ {
+ }
+
+ public TransactionConstructorException(string message, Exception inner)
+ : base(message, inner)
+ {
+ }
+ }
+
/// <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 long nCent = 10000;
+
+ /// <summary>
+ /// One coin = 1000000 satoshis.
+ /// </summary>
+ public const long nCoin = 1000000;
+
+ /// <summary>
+ /// Sanity checking threshold.
+ /// </summary>
+ public const long nMaxMoney = 2000000000 * nCoin;
+
+ public const long nMinTxFee = nCent / 10;
+ public const long nMinRelayTxFee = nCent / 50;
+ public const long 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>
- public uint nVersion = 1;
+ public uint nVersion;
/// <summary>
/// Transaction timestamp.
/// </summary>
- public uint nTime = 0;
+ public uint nTime;
/// <summary>
/// Array of transaction inputs
/// <summary>
/// Block height or timestamp when transaction is final
/// </summary>
- public uint nLockTime = 0;
+ public uint nLockTime;
/// <summary>
/// Initialize an empty instance
// Initialize empty input and output arrays. Please note that such
// configuration is not valid for real transaction, you have to supply
// at least one input and one output.
+ nVersion = 1;
+ nTime = 0;
vin = new CTxIn[0];
vout = new CTxOut[0];
+ nLockTime = 0;
}
/// <summary>
nLockTime = tx.nLockTime;
}
+ /// <summary>
+ /// Attempts to execute all transaction scripts and validate the results.
+ /// </summary>
+ /// <returns>Checking result.</returns>
+ public bool VerifyScripts()
+ {
+ if (IsCoinBase)
+ {
+ return true;
+ }
+
+ for (int i = 0; i < vin.Length; i++)
+ {
+ var outpoint = vin[i].prevout;
+
+ TxOutItem txOutCursor;
+ if (!CBlockStore.Instance.GetTxOutCursor(outpoint, out txOutCursor))
+ return false;
+
+ if (!ScriptCode.VerifyScript(vin[i].scriptSig, txOutCursor.scriptPubKey, this, i, (int)scriptflag.SCRIPT_VERIFY_P2SH, 0))
+ return false;
+ }
+
+ return true;
+ }
/// <summary>
- /// Parse byte sequence and initialize new instance of CTransaction
+ /// Calculate amount of signature operations without trying to properly evaluate P2SH scripts.
/// </summary>
- /// <param name="txBytes">Byte sequence</param>
- public CTransaction(IList<byte> txBytes)
+ public uint LegacySigOpCount
{
- ByteQueue wBytes = new ByteQueue(txBytes);
+ get
+ {
+ uint nSigOps = 0;
- nVersion = BitConverter.ToUInt32(wBytes.Get(4), 0);
- nTime = BitConverter.ToUInt32(wBytes.Get(4), 0);
+ if (!IsCoinBase)
+ {
+ // http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2012-July/001718.html
- int nInputs = (int)(int)wBytes.GetVarInt();
- vin = new CTxIn[nInputs];
+ foreach (var txin in vin)
+ {
+ nSigOps += txin.scriptSig.GetSigOpCount(false);
+ }
+ }
+
+ foreach (var txout in vout)
+ {
+ nSigOps += txout.scriptPubKey.GetSigOpCount(false);
+ }
- for (int nCurrentInput = 0; nCurrentInput < nInputs; nCurrentInput++)
+ return nSigOps;
+ }
+ }
+
+ /// <summary>
+ /// Basic sanity checkings
+ /// </summary>
+ /// <returns>Checking result</returns>
+ public bool CheckTransaction()
+ {
+ if (Size > nMaxTxSize || vin.Length == 0 || vout.Length == 0)
{
- // Fill inputs array
- vin[nCurrentInput] = new CTxIn();
-
- vin[nCurrentInput].prevout = new COutPoint(wBytes.Get(36));
+ return false;
+ }
- int nScriptSigLen = (int)wBytes.GetVarInt();
- vin[nCurrentInput].scriptSig = new CScript(wBytes.Get(nScriptSigLen));
+ // Check for empty or overflow output values
+ long nValueOut = 0;
+ for (int i = 0; i < vout.Length; i++)
+ {
+ CTxOut txout = vout[i];
+ if (txout.IsEmpty && !IsCoinBase && !IsCoinStake)
+ {
+ // Empty outputs aren't allowed for user transactions.
+ return false;
+ }
- vin[nCurrentInput].nSequence = BitConverter.ToUInt32(wBytes.Get(4), 0);
+ nValueOut += txout.nValue;
+ if (!MoneyRange(nValueOut))
+ {
+ return false;
+ }
}
- int nOutputs = (int)wBytes.GetVarInt();
- vout = new CTxOut[nOutputs];
+ // Check for duplicate inputs
+ var InOutPoints = new List<COutPoint>();
+ foreach (var txin in vin)
+ {
+ if (InOutPoints.IndexOf(txin.prevout) != -1)
+ {
+ // Duplicate input.
+ return false;
+ }
+ InOutPoints.Add(txin.prevout);
+ }
- for (int nCurrentOutput = 0; nCurrentOutput < nOutputs; nCurrentOutput++)
+ if (IsCoinBase)
+ {
+ if (vin[0].scriptSig.Size < 2 || vin[0].scriptSig.Size > 100)
+ {
+ // Script size is invalid
+ return false;
+ }
+ }
+ else
{
- // Fill outputs array
- vout[nCurrentOutput] = new CTxOut();
- vout[nCurrentOutput].nValue = BitConverter.ToInt64(wBytes.Get(8), 0);
+ foreach (var txin in vin)
+ {
+ if (txin.prevout.IsNull)
+ {
+ // Null input in non-coinbase transaction.
+ return false;
+ }
+ }
+ }
+
+ return true;
+ }
- int nScriptPKLen = (int)wBytes.GetVarInt();
- vout[nCurrentOutput].scriptPubKey = new CScript(wBytes.Get(nScriptPKLen));
+ public bool IsFinal(uint nBlockHeight = 0, uint nBlockTime = 0)
+ {
+ // Time based nLockTime
+ if (nLockTime == 0)
+ {
+ return true;
+ }
+ if (nBlockHeight == 0)
+ {
+ nBlockHeight = uint.MaxValue; // TODO: stupid stub here, should be best height instead.
+ }
+ if (nBlockTime == 0)
+ {
+ nBlockTime = NetInfo.GetAdjustedTime();
+ }
+ if (nLockTime < (nLockTime < NetInfo.nLockTimeThreshold ? nBlockHeight : nBlockTime))
+ {
+ return true;
}
+ foreach (var txin in vin)
+ {
+ if (!txin.IsFinal)
+ {
+ return false;
+ }
+ }
+ return true;
+ }
- nLockTime = BitConverter.ToUInt32(wBytes.Get(4), 0);
+ /// <summary>
+ /// Parse byte sequence and initialize new instance of CTransaction
+ /// </summary>
+ /// <param name="txBytes">Byte sequence</param>
+ public CTransaction(byte[] txBytes)
+ {
+ try
+ {
+ var stream = new MemoryStream(txBytes);
+ var reader = new BinaryReader(stream);
+
+ nVersion = reader.ReadUInt32();
+ nTime = reader.ReadUInt32();
+
+ int nInputs = (int)VarInt.ReadVarInt(ref reader);
+ vin = new CTxIn[nInputs];
+
+ for (int nCurrentInput = 0; nCurrentInput < nInputs; nCurrentInput++)
+ {
+ // Fill inputs array
+ vin[nCurrentInput] = new CTxIn();
+
+ vin[nCurrentInput].prevout = new COutPoint(reader.ReadBytes(36));
+
+ int nScriptSigLen = (int)VarInt.ReadVarInt(ref reader);
+ vin[nCurrentInput].scriptSig = new CScript(reader.ReadBytes(nScriptSigLen));
+
+ vin[nCurrentInput].nSequence = reader.ReadUInt32();
+ }
+
+ int nOutputs = (int)VarInt.ReadVarInt(ref reader);
+ vout = new CTxOut[nOutputs];
+
+ for (int nCurrentOutput = 0; nCurrentOutput < nOutputs; nCurrentOutput++)
+ {
+ // Fill outputs array
+ vout[nCurrentOutput] = new CTxOut();
+ vout[nCurrentOutput].nValue = reader.ReadInt64();
+
+ int nScriptPKLen = (int)VarInt.ReadVarInt(ref reader);
+ vout[nCurrentOutput].scriptPubKey = new CScript(reader.ReadBytes(nScriptPKLen));
+ }
+
+ nLockTime = reader.ReadUInt32();
+ }
+ catch (Exception e)
+ {
+ throw new TransactionConstructorException("Deserialization failed", e);
+ }
+ }
+
+ /// <summary>
+ /// Serialized size
+ /// </summary>
+ public uint Size
+ {
+ get
+ {
+ uint nSize = 12; // nVersion, nTime, nLockLime
+
+ nSize += VarInt.GetEncodedSize(vin.Length);
+ nSize += VarInt.GetEncodedSize(vout.Length);
+
+ foreach (var input in vin)
+ {
+ nSize += input.Size;
+ }
+
+ foreach (var output in vout)
+ {
+ nSize += output.Size;
+ }
+
+ return nSize;
+ }
}
/// <summary>
/// </summary>
/// <param name="wTxBytes">Bytes sequence</param>
/// <returns>Transactions array</returns>
- public static CTransaction[] ReadTransactionsList(ref ByteQueue wTxBytes)
+ internal static CTransaction[] ReadTransactionsList(ref BinaryReader reader)
{
- CTransaction[] tx;
+ try
+ {
+ // Read amount of transactions
+ int nTransactions = (int)VarInt.ReadVarInt(ref reader);
+ var tx = new CTransaction[nTransactions];
+
+ for (int nTx = 0; nTx < nTransactions; nTx++)
+ {
+ // Fill the transactions array
+ tx[nTx] = new CTransaction();
- // Read amount of transactions
- int nTransactions = (int)wTxBytes.GetVarInt();
- tx = new CTransaction[nTransactions];
+ tx[nTx].nVersion = reader.ReadUInt32();
+ tx[nTx].nTime = reader.ReadUInt32();
- for (int nTx = 0; nTx < nTransactions; nTx++)
- {
- // Fill the transactions array
- tx[nTx] = new CTransaction();
+ // Inputs array
+ tx[nTx].vin = CTxIn.ReadTxInList(ref reader);
- tx[nTx].nVersion = BitConverter.ToUInt32(wTxBytes.Get(4), 0);
- tx[nTx].nTime = BitConverter.ToUInt32(wTxBytes.Get(4), 0);
+ // outputs array
+ tx[nTx].vout = CTxOut.ReadTxOutList(ref reader);
- // Inputs array
- tx[nTx].vin = CTxIn.ReadTxInList(ref wTxBytes);
+ tx[nTx].nLockTime = reader.ReadUInt32();
+ }
- // outputs array
- tx[nTx].vout = CTxOut.ReadTxOutList(ref wTxBytes);
+ return tx;
- tx[nTx].nLockTime = BitConverter.ToUInt32(wTxBytes.Get(4), 0);
}
-
- return tx;
+ catch (Exception e)
+ {
+ throw new TransactionConstructorException("Deserialization failed", e);
+ }
}
public bool IsCoinBase
/// <summary>
/// Transaction hash
/// </summary>
- public Hash256 Hash
+ public uint256 Hash
{
- get { return Hash256.Compute256(Bytes); }
+ get { return CryptoUtils.ComputeHash256(this); }
}
/// <summary>
- /// A sequence of bytes, which corresponds to the current state of CTransaction.
+ /// Amount of novacoins spent by this transaction.
/// </summary>
- public IList<byte> Bytes
+ public long nValueOut
{
get
{
- List<byte> resultBytes = new List<byte>();
-
- // Typical transaction example:
- //
- // 01000000 -- version
- // 78b4c953 -- timestamp
- // 06 -- amount of txins
- // 340d96b77ec4ee9d42b31cadc2fab911e48d48c36274d516f226d5e85bbc512c -- txin hash
- // 01000000 -- txin outnumber
- // 6b -- txin scriptSig length
- // 483045022100c8df1fc17b6ea1355a39b92146ec67b3b53565e636e028010d3a8a87f6f805f202203888b9b74df03c3960773f2a81b2dfd1efb08bb036a8f3600bd24d5ed694cd5a0121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // 364c640420de8fa77313475970bf09ce4d0b1f8eabb8f1d6ea49d90c85b202ee -- txin hash
- // 01000000 -- txin outnumber
- // 6b -- txin scriptSig length
- // 483045022100b651bf3a6835d714d2c990c742136d769258d0170c9aac24803b986050a8655b0220623651077ff14b0a9d61e30e30f2c15352f70491096f0ec655ae1c79a44e53aa0121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // 7adbd5f2e521f567bfea2cb63e65d55e66c83563fe253464b75184a5e462043d -- txin hash
- // 00000000 -- txin outnumber
- // 6a -- txin scriptSig length
- // 4730440220183609f2b995993acc9df241aff722d48b9a731b0cd376212934565723ed81f00220737e7ce75ef39bdc061d0dcdba3ee24e43b899696a7c96803cee0a79e1f78ecb0121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // 999eb03e00a41c2f9fde8865a554ceebbc48d30f4c8ba22dd88da8c9b46fa920 -- txin hash
- // 03000000 -- txin outnumber
- // 6b -- txin scriptSig length
- // 483045022100ec1ab104ef086ba79b0f2611ebf1bfdd22a7a1020f6630fa1c6707546626e0db022056093d4048a999392185ccc735ef736a5497bd68f60b42e6c0c93ba770b54d010121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // c0543b86be257ddd85b014a76718a70fab9eaa3c477460e4ca187094d86f369c -- txin hash
- // 05000000 -- txin outnumber
- // 69 -- txin scriptSig length
- // 463043021f24275c72f952043174daf01d7f713f878625f0522124a3cab48a0a2e12604202201b47742e6697b0ebdd1e4ba49c74baf142a0228ad0e0ee847488994c9dce78470121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // e1793d4519147782293dd1db6d90e461265d91db2cc6889c37209394d42ad10d -- txin hash
- // 05000000 -- txin outnumber
- // 6a -- txin scriptSig length
- // 473044022018a0c3d73b2765d75380614ab36ee8e3c937080894a19166128b1e3357b208fb0220233c9609985f535547381431526867ad0255ec4969afe5c360544992ed6b3ed60121030dd13e6d3c63fa10cc0b6bf968fbbfcb9a988b333813b1f22d04fa60e344bc4c -- txin scriptSig
- // ffffffff -- txin nSequence
- // 02 -- amount of txouts
- // e542000000000000 -- txout value
- // 19 -- scriptPubKey length
- // 76a91457d84c814b14bd86bf32f106b733baa693db7dc788ac -- scriptPubKey
- // 409c000000000000 -- txout value
- // 19 -- scriptPubKey length
- // 76a91408c8768d5d6bf7c1d9609da4e766c3f1752247b188ac -- scriptPubKey
- // 00000000 -- lock time
-
- resultBytes.AddRange(BitConverter.GetBytes(nVersion));
- resultBytes.AddRange(BitConverter.GetBytes(nTime));
- resultBytes.AddRange(VarInt.EncodeVarInt(vin.LongLength));
-
- foreach (CTxIn input in vin)
+ long nValueOut = 0;
+ foreach (var txout in vout)
{
- resultBytes.AddRange(input.Bytes);
+ nValueOut += txout.nValue;
+ Contract.Assert(MoneyRange(txout.nValue) && MoneyRange(nValueOut));
}
+ return nValueOut;
+ }
+ }
- resultBytes.AddRange(VarInt.EncodeVarInt(vout.LongLength));
+ /// <summary>
+ /// A sequence of bytes, which corresponds to the current state of CTransaction.
+ /// </summary>
+ public static implicit operator byte[] (CTransaction tx)
+ {
+ var stream = new MemoryStream();
+ var writer = new BinaryWriter(stream);
- foreach (CTxOut output in vout)
- {
- resultBytes.AddRange(output.Bytes);
- }
+ writer.Write(tx.nVersion);
+ writer.Write(tx.nTime);
+ writer.Write(VarInt.EncodeVarInt(tx.vin.LongLength));
- resultBytes.AddRange(BitConverter.GetBytes(nLockTime));
+ foreach (var input in tx.vin)
+ {
+ writer.Write(input);
+ }
+
+ writer.Write(VarInt.EncodeVarInt(tx.vout.LongLength));
- return resultBytes;
+ foreach (var output in tx.vout)
+ {
+ writer.Write(output);
}
+
+ writer.Write(tx.nLockTime);
+ var resultBytes = stream.ToArray();
+ writer.Close();
+
+ return resultBytes;
}
public override string ToString()
{
- StringBuilder sb = new StringBuilder();
+ var sb = new StringBuilder();
sb.AppendFormat("CTransaction(\n nVersion={0},\n nTime={1},\n", nVersion, nTime);
- foreach (CTxIn txin in vin)
+ foreach (var txin in vin)
{
- sb.AppendFormat(" {0},\n", txin.ToString());
+ sb.AppendFormat(" {0},\n", txin);
}
- foreach (CTxOut txout in vout)
+ foreach (var txout in vout)
{
- sb.AppendFormat(" {0},\n", txout.ToString());
+ sb.AppendFormat(" {0},\n", txout);
}
sb.AppendFormat("\nnLockTime={0}\n)", nLockTime);
return sb.ToString();
}
- }
+
+ public static bool MoneyRange(long 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 long GetValueIn(ref Dictionary<COutPoint, TxOutItem> inputs)
+ {
+ if (IsCoinBase)
+ {
+ return 0;
+ }
+
+ long 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 long 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
+ }
+
+ long nValueIn = input.nValue;
+ bnCentSecond += new BigInteger(nValueIn) * (nTime - merkleItem.nTime) / nCent;
+ }
+
+ BigInteger bnCoinDay = bnCentSecond * nCent / nCoin / (24 * 60 * 60);
+ nCoinAge = (long)bnCoinDay;
+
+ return true;
+ }
+
+ public long GetMinFee(uint nBlockSize, bool fAllowFree, MinFeeMode mode)
+ {
+ long 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
+ long nBaseFee = (mode == MinFeeMode.GMF_RELAY) ? nMinRelayTxFee : nMinTxFee;
+
+ uint nNewBlockSize = nBlockSize + nBytes;
+ long nMinFee = (1 + (long)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;
+ }
+ }
}