public MemoryBlockchain(Block? genesisBlock = null)
{
this.shutdownToken = new CancellationToken();
this.random = new Random();
// create the key pair that block rewards will be sent to
var keyPair = TransactionManager.CreateKeyPair();
this._coinbasePrivateKey = keyPair.Item1;
this._coinbasePublicKey = keyPair.Item2;
// initialize unit test storage
this._storageContext = new MemoryStorageContext();
this._cacheContext = new CacheContext(this._storageContext);
// initialize unit test rules
this._rules = new UnitTestRules(this._cacheContext);
// initialize blockchain calculator
this._calculator = new BlockchainCalculator(this._rules, this._cacheContext, this.shutdownToken);
// create and mine the genesis block
this._genesisBlock = genesisBlock ?? MineEmptyBlock(0);
// update genesis blockchain and add to storage
this._rules.SetGenesisBlock(this._genesisBlock);
this._currentBlockchain = this._rules.GenesisBlockchain;
this._genesisChainedBlock = AddBlock(this._genesisBlock, null).Item2;
}
public void SetGenesisBlock(Block genesisBlock)
{
this._genesisBlock = genesisBlock;
this._genesisChainedBlock =
new ChainedBlock
(
blockHash: this._genesisBlock.Hash,
previousBlockHash: this._genesisBlock.Header.PreviousBlock,
height: 0,
totalWork: this._genesisBlock.Header.CalculateWork()
);
this._genesisBlockchain =
new Data.Blockchain
(
blockList: ImmutableList.Create(this._genesisChainedBlock),
blockListHashes: ImmutableHashSet.Create(this._genesisBlock.Hash),
utxo: ImmutableDictionary.Create<UInt256, UnspentTx>() // genesis block coinbase is not included in utxo, it is unspendable
);
}
public Block CreateEmptyBlock(UInt256 previousBlockHash)
{
var coinbaseTx = new Transaction
(
version: 0,
inputs: ImmutableArray.Create
(
new TxInput
(
previousTxOutputKey: new TxOutputKey
(
txHash: 0,
txOutputIndex: 0
),
scriptSignature: ImmutableArray.Create(random.NextBytes(100)),
sequence: 0
)
),
outputs: ImmutableArray.Create
(
new TxOutput
(
value: 50 * SATOSHI_PER_BTC,
scriptPublicKey: ImmutableArray.Create(TransactionManager.CreatePublicKeyScript(_coinbasePublicKey))
)
),
lockTime: 0
);
//Debug.WriteLine("Coinbase Tx Created: {0}".Format2(coinbaseTx.Hash.ToHexNumberString()));
var transactions = ImmutableArray.Create(coinbaseTx);
var merkleRoot = DataCalculator.CalculateMerkleRoot(transactions);
var block = new Block
(
header: new BlockHeader
(
version: 0,
previousBlock: previousBlockHash,
merkleRoot: merkleRoot,
time: 0,
bits: DataCalculator.TargetToBits(this._rules.HighestTarget),
nonce: 0
),
transactions: transactions
);
return block;
}
public Tuple<Block, ChainedBlock> AddBlock(Block block, ChainedBlock? prevChainedBlock)
{
if (prevChainedBlock != null)
Assert.AreEqual(block.Header.PreviousBlock, prevChainedBlock.Value.BlockHash);
var chainedBlock = new ChainedBlock
(
block.Hash,
block.Header.PreviousBlock,
prevChainedBlock != null ? prevChainedBlock.Value.Height + 1 : 0,
prevChainedBlock != null ? prevChainedBlock.Value.TotalWork + block.Header.CalculateWork() : block.Header.CalculateWork()
);
this.CacheContext.BlockCache.CreateValue(block.Hash, block);
this.CacheContext.ChainedBlockCache.CreateValue(block.Hash, chainedBlock);
ChooseNewWinner();
return Tuple.Create(block, chainedBlock);
}
public static byte[] EncodeBlock(Block block)
{
var stream = new MemoryStream();
EncodeBlock(stream, block);
return stream.ToArray();
}
public void RevalidateBlockchain(Data.Blockchain blockchain, Block genesisBlock)
{
var stopwatch = new Stopwatch();
stopwatch.Start();
try
{
//TODO delete corrupted data? could get stuck in a fail-loop on the winning chain otherwise
// verify blockchain has blocks
if (blockchain.BlockList.Count == 0)
throw new ValidationException();
// verify genesis block hash
if (blockchain.BlockList[0].BlockHash != genesisBlock.Hash)
throw new ValidationException();
// get genesis block header
var chainGenesisBlockHeader = this.CacheContext.GetBlockHeader(blockchain.BlockList[0].BlockHash);
// verify genesis block header
if (
genesisBlock.Header.Version != chainGenesisBlockHeader.Version
|| genesisBlock.Header.PreviousBlock != chainGenesisBlockHeader.PreviousBlock
|| genesisBlock.Header.MerkleRoot != chainGenesisBlockHeader.MerkleRoot
|| genesisBlock.Header.Time != chainGenesisBlockHeader.Time
|| genesisBlock.Header.Bits != chainGenesisBlockHeader.Bits
|| genesisBlock.Header.Nonce != chainGenesisBlockHeader.Nonce
|| genesisBlock.Hash != chainGenesisBlockHeader.Hash
|| genesisBlock.Hash != CalculateHash(chainGenesisBlockHeader))
{
throw new ValidationException();
}
// setup expected previous block hash value to verify each chain actually does link
var expectedPreviousBlockHash = genesisBlock.Header.PreviousBlock;
for (var height = 0; height < blockchain.BlockList.Count; height++)
{
// cooperative loop
this.shutdownToken.ThrowIfCancellationRequested();
// get the current link in the chain
var chainedBlock = blockchain.BlockList[height];
// verify height
if (chainedBlock.Height != height)
throw new ValidationException();
// verify blockchain linking
if (chainedBlock.PreviousBlockHash != expectedPreviousBlockHash)
throw new ValidationException();
// verify block exists
var blockHeader = this.CacheContext.GetBlockHeader(chainedBlock.BlockHash);
// verify block metadata matches header values
if (blockHeader.PreviousBlock != chainedBlock.PreviousBlockHash)
throw new ValidationException();
// verify block header hash
if (CalculateHash(blockHeader) != chainedBlock.BlockHash)
throw new ValidationException();
// next block metadata should have the current metadata's hash as its previous hash value
expectedPreviousBlockHash = chainedBlock.BlockHash;
}
// all validation passed
}
finally
{
stopwatch.Stop();
Debug.WriteLine("Blockchain revalidation: {0:#,##0.000000}s".Format2(stopwatch.ElapsedSecondsFloat()));
}
}
private ImmutableDictionary<UInt256, UnspentTx> CalculateUtxo(long blockHeight, Block block, ImmutableDictionary<UInt256, UnspentTx> currentUtxo, out ImmutableDictionary<UInt256, ImmutableHashSet<int>> newTransactions, out long txCount, out long inputCount)
{
txCount = 0;
inputCount = 0;
// create builder for new utxo
var newUtxoBuilder = currentUtxo.ToBuilder();
var newTransactionsBuilder = ImmutableDictionary.CreateBuilder<UInt256, ImmutableHashSet<int>>();
// don't include genesis block coinbase in utxo
if (blockHeight > 0)
{
//TODO apply real coinbase rule
// https://github.com/bitcoin/bitcoin/blob/481d89979457d69da07edd99fba451fd42a47f5c/src/core.h#L219
var coinbaseTx = block.Transactions[0];
// add the coinbase outputs to the utxo
var coinbaseUnspentTx = new UnspentTx(block.Hash, 0, coinbaseTx.Hash, new ImmutableBitArray(coinbaseTx.Outputs.Length, true));
// add transaction output to to the utxo
if (newUtxoBuilder.ContainsKey(coinbaseTx.Hash))
{
// duplicate transaction output
Debug.WriteLine("Duplicate transaction at block {0:#,##0}, {1}, coinbase".Format2(blockHeight, block.Hash.ToHexNumberString()));
if ((blockHeight == 91842 && coinbaseTx.Hash == UInt256.Parse("d5d27987d2a3dfc724e359870c6644b40e497bdc0589a033220fe15429d88599", NumberStyles.HexNumber))
|| (blockHeight == 91880 && coinbaseTx.Hash == UInt256.Parse("e3bf3d07d4b0375638d5f1db5255fe07ba2c4cb067cd81b84ee974b6585fb468", NumberStyles.HexNumber)))
{
newUtxoBuilder.Remove(coinbaseTx.Hash);
}
else
{
throw new ValidationException();
}
}
newTransactionsBuilder.Add(coinbaseTx.Hash, ImmutableHashSet.Create(0));
newUtxoBuilder.Add(coinbaseTx.Hash, coinbaseUnspentTx);
}
// check for double spends
for (var txIndex = 1; txIndex < block.Transactions.Length; txIndex++)
{
var tx = block.Transactions[txIndex];
txCount++;
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
inputCount++;
if (!newUtxoBuilder.ContainsKey(input.PreviousTxOutputKey.TxHash))
{
// output wasn't present in utxo, invalid block
throw new ValidationException();
}
var prevUnspentTx = newUtxoBuilder[input.PreviousTxOutputKey.TxHash];
if (input.PreviousTxOutputKey.TxOutputIndex >= prevUnspentTx.UnspentOutputs.Length)
{
// output was out of bounds
throw new ValidationException();
}
if (!prevUnspentTx.UnspentOutputs[input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked()])
{ // output was already spent
throw new ValidationException();
}
// remove the output from the utxo
newUtxoBuilder[input.PreviousTxOutputKey.TxHash] =
new UnspentTx(prevUnspentTx.BlockHash, prevUnspentTx.TxIndex, prevUnspentTx.TxHash,
prevUnspentTx.UnspentOutputs.Set(input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked(), false));
// remove fully spent transaction from the utxo
if (newUtxoBuilder[input.PreviousTxOutputKey.TxHash].UnspentOutputs.All(x => !x))
newUtxoBuilder.Remove(input.PreviousTxOutputKey.TxHash);
}
// add the output to the list to be added to the utxo
var unspentTx = new UnspentTx(block.Hash, (UInt32)txIndex, tx.Hash, new ImmutableBitArray(tx.Outputs.Length, true));
// add transaction output to to the utxo
if (newUtxoBuilder.ContainsKey(tx.Hash))
{
// duplicate transaction output
Debug.WriteLine("Duplicate transaction at block {0:#,##0}, {1}, tx {2}".Format2(blockHeight, block.Hash.ToHexNumberString(), txIndex));
//Debugger.Break();
//TODO throw new Validation();
//TODO this needs to be tracked so that blocks can be rolled back accurately
//TODO track these separately on the blockchain info? gonna be costly to track on every transaction
}
if (!newTransactionsBuilder.ContainsKey(tx.Hash))
newTransactionsBuilder.Add(tx.Hash, ImmutableHashSet.Create(txIndex));
else
newTransactionsBuilder[tx.Hash] = newTransactionsBuilder[tx.Hash].Add(txIndex);
newUtxoBuilder.Add(tx.Hash, unspentTx);
}
// validation successful, return the new utxo
newTransactions = newTransactionsBuilder.ToImmutable();
return newUtxoBuilder.ToImmutable();
}
public Data.Blockchain RollbackBlockchain(Data.Blockchain blockchain, Block block)
{
List<TxOutputKey> spendOutputs, receiveOutputs;
return RollbackBlockchain(blockchain, block, out spendOutputs, out receiveOutputs);
}
public Block MineEmptyBlock(Block previousBlock)
{
return MineEmptyBlock(previousBlock.Hash);
}
public virtual void ValidateBlock(Block block, Data.Blockchain blockchain, ImmutableDictionary<UInt256, UnspentTx> utxo, ImmutableDictionary<UInt256, ImmutableHashSet<int>> newTransactions/*, ImmutableDictionary<UInt256, Transaction> transactions*/)
{
//TODO
if (BypassValidation)
return;
// calculate the next required target
var requiredTarget = GetRequiredNextTarget(blockchain);
// validate block's target against the required target
var blockTarget = block.Header.CalculateTarget();
if (blockTarget > requiredTarget)
{
throw new ValidationException("Failing block {0} at height {1}: Block target {2} did not match required target of {3}".Format2(block.Hash.ToHexNumberString(), blockchain.Height, blockTarget.ToHexNumberString(), requiredTarget.ToHexNumberString()));
}
// validate block's proof of work against its stated target
if (block.Hash > blockTarget || block.Hash > requiredTarget)
{
throw new ValidationException("Failing block {0} at height {1}: Block did not match its own target of {2}".Format2(block.Hash.ToHexNumberString(), blockchain.Height, blockTarget.ToHexNumberString()));
}
// ensure there is at least 1 transaction
if (block.Transactions.Length == 0)
{
throw new ValidationException("Failing block {0} at height {1}: Zero transactions present".Format2(block.Hash.ToHexNumberString(), blockchain.Height));
}
//TODO apply real coinbase rule
// https://github.com/bitcoin/bitcoin/blob/481d89979457d69da07edd99fba451fd42a47f5c/src/core.h#L219
var coinbaseTx = block.Transactions[0];
// check that coinbase has only one input
if (coinbaseTx.Inputs.Length != 1)
{
throw new ValidationException("Failing block {0} at height {1}: Coinbase transaction does not have exactly one input".Format2(block.Hash.ToHexNumberString(), blockchain.Height));
}
// validate transactions in parallel
long unspentValue = 0L;
try
{
Parallel.For(1, block.Transactions.Length, (txIndex, loopState) =>
{
var tx = block.Transactions[txIndex];
long unspentValueInner;
//TODO utxo will not be correct at transaction if a tx hash is reused within the same block
ValidateTransaction(blockchain.Height, block, tx, txIndex, utxo, newTransactions, out unspentValueInner);
Interlocked.Add(ref unspentValue, unspentValueInner);
});
}
catch (AggregateException e)
{
var validationException = e.InnerExceptions.FirstOrDefault(x => x is ValidationException);
var missingDataException = e.InnerExceptions.FirstOrDefault(x => x is MissingDataException);
if (validationException != null)
throw validationException;
if (missingDataException != null)
throw missingDataException;
throw;
}
//TODO utxo will not be correct at transaction if a tx hash is reused within the same block
ValidateTransactionScripts(block, utxo, newTransactions);
// calculate the expected reward in coinbase
var expectedReward = (long)(50 * SATOSHI_PER_BTC);
if (blockchain.Height / 210000 <= 32)
expectedReward /= (long)Math.Pow(2, blockchain.Height / 210000);
expectedReward += unspentValue;
// calculate the actual reward in coinbase
var actualReward = 0L;
foreach (var txOutput in coinbaseTx.Outputs)
actualReward += (long)txOutput.Value;
// ensure coinbase has correct reward
if (actualReward > expectedReward)
{
throw new ValidationException("Failing block {0} at height {1}: Coinbase value is greater than reward + fees".Format2(block.Hash.ToHexNumberString(), blockchain.Height));
}
// all validation has passed
}
private void OnBlockModification(UInt256 blockHash, Block block)
{
OnBlockAddition(blockHash);
}
public bool TryGetBlock(UInt256 blockHash, out Block block, bool saveInCache = true)
{
if (this.CacheContext.BlockCache.TryGetValue(blockHash, out block, saveInCache))
{
this.missingBlocks.Remove(blockHash);
return true;
}
else
{
this.missingBlocks.Add(blockHash);
block = default(Block);
return false;
}
}
public Testnet2Rules(CacheContext cacheContext)
: base(cacheContext)
{
this._genesisBlock =
new Block
(
header: new BlockHeader
(
version: 1,
previousBlock: 0,
merkleRoot: UInt256.Parse("4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b", NumberStyles.HexNumber),
time: 1296688602,
bits: 0x207FFFFF,
nonce: 2
),
transactions: ImmutableArray.Create
(
new Transaction
(
version: 1,
inputs: ImmutableArray.Create
(
new TxInput
(
previousTxOutputKey: new TxOutputKey
(
txHash: 0,
txOutputIndex: 0xFFFFFFFF
),
scriptSignature: ImmutableArray.Create<byte>
(
0x04, 0xFF, 0xFF, 0x00, 0x1D, 0x01, 0x04, 0x45, 0x54, 0x68, 0x65, 0x20, 0x54, 0x69, 0x6D, 0x65,
0x73, 0x20, 0x30, 0x33, 0x2F, 0x4A, 0x61, 0x6E, 0x2F, 0x32, 0x30, 0x30, 0x39, 0x20, 0x43, 0x68,
0x61, 0x6E, 0x63, 0x65, 0x6C, 0x6C, 0x6F, 0x72, 0x20, 0x6F, 0x6E, 0x20, 0x62, 0x72, 0x69, 0x6E,
0x6B, 0x20, 0x6F, 0x66, 0x20, 0x73, 0x65, 0x63, 0x6F, 0x6E, 0x64, 0x20, 0x62, 0x61, 0x69, 0x6C,
0x6F, 0x75, 0x74, 0x20, 0x66, 0x6F, 0x72, 0x20, 0x62, 0x61, 0x6E, 0x6B, 0x73
),
sequence: 0xFFFFFFFF
)
),
outputs: ImmutableArray.Create
(
new TxOutput
(
value: (UInt64)(50L * 100.MILLION()),
scriptPublicKey: ImmutableArray.Create<byte>
(
0x41, 0x04, 0x67, 0x8A, 0xFD, 0xB0, 0xFE, 0x55, 0x48, 0x27, 0x19, 0x67, 0xF1, 0xA6, 0x71, 0x30,
0xB7, 0x10, 0x5C, 0xD6, 0xA8, 0x28, 0xE0, 0x39, 0x09, 0xA6, 0x79, 0x62, 0xE0, 0xEA, 0x1F, 0x61,
0xDE, 0xB6, 0x49, 0xF6, 0xBC, 0x3F, 0x4C, 0xEF, 0x38, 0xC4, 0xF3, 0x55, 0x04, 0xE5, 0x1E, 0xC1,
0x12, 0xDE, 0x5C, 0x38, 0x4D, 0xF7, 0xBA, 0x0B, 0x8D, 0x57, 0x8A, 0x4C, 0x70, 0x2B, 0x6B, 0xF1,
0x1D, 0x5F, 0xAC
)
)
),
lockTime: 0
)
)
);
Debug.Assert(_genesisBlock.Hash == UInt256.Parse("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206", NumberStyles.HexNumber));
this._genesisChainedBlock =
new ChainedBlock
(
blockHash: this._genesisBlock.Hash,
previousBlockHash: this._genesisBlock.Header.PreviousBlock,
height: 0,
totalWork: this._genesisBlock.Header.CalculateWork()
);
this._genesisBlockchain =
new Data.Blockchain
(
blockList: ImmutableList.Create(this._genesisChainedBlock),
blockListHashes: ImmutableHashSet.Create(this._genesisBlock.Hash),
utxo: ImmutableDictionary.Create<UInt256, UnspentTx>() // genesis block coinbase is not included in utxo, it is unspendable
);
}
public static void GetTransaction(BlockProvider blockProvider, int blockIndex, int txIndex, out Block block, out Transaction tx)
{
block = blockProvider.GetBlock(blockIndex);
tx = block.Transactions[txIndex];
}
public static void GetFirstTransaction(BlockProvider blockProvider, out Block block, out Transaction tx, out IDictionary<UInt256, Transaction> txLookup)
{
txLookup = new Dictionary<UInt256, Transaction>();
// prior outputs for first transaction
GetTransaction(blockProvider, 9, 0, out block, out tx);
txLookup.Add(tx.Hash, tx);
// first transaction
// do this last so its output is what is returned
GetTransaction(blockProvider, 170, 1, out block, out tx);
txLookup.Add(tx.Hash, tx);
}
public Tuple<Block, ChainedBlock> MineAndAddBlock(Block block, ChainedBlock? prevChainedBlock)
{
var minedHeader = Miner.MineBlockHeader(block.Header, this._rules.HighestTarget);
if (minedHeader == null)
Assert.Fail("No block could be mined for test data header.");
var minedBlock = block.With(Header: minedHeader);
return AddBlock(minedBlock, prevChainedBlock);
}
public Block MineBlock(Block block)
{
var minedHeader = Miner.MineBlockHeader(block.Header, this._rules.HighestTarget);
if (minedHeader == null)
Assert.Fail("No block could be mined for test data header.");
block = block.With(Header: minedHeader);
return block;
}
//TODO utxo needs to be as-at transaction, with regards to a transaction being fully spent and added back in in the same block
public virtual void ValidateTransaction(long blockHeight, Block block, Transaction tx, int txIndex, ImmutableDictionary<UInt256, UnspentTx> utxo, ImmutableDictionary<UInt256, ImmutableHashSet<int>> newTransactions, out long unspentValue /*, ImmutableDictionary<UInt256, Transaction> transactions*/)
{
unspentValue = -1;
// lookup all previous outputs
var prevOutputMissing = false;
var previousOutputs = new Dictionary<TxOutputKey, Tuple<TxInput, int, TxOutput>>();
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
// find previous transaction
var prevTx = GetPreviousTransaction(block, txIndex, input.PreviousTxOutputKey, utxo, newTransactions);
// find previous transaction output
if (input.PreviousTxOutputKey.TxOutputIndex >= prevTx.Outputs.Length)
throw new ValidationException();
var prevOutput = prevTx.Outputs[input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked()];
previousOutputs.Add(input.PreviousTxOutputKey, Tuple.Create(input, inputIndex, prevOutput));
}
if (prevOutputMissing)
{
throw new ValidationException();
}
// verify spend amounts
var txInputValue = (UInt64)0;
var txOutputValue = (UInt64)0;
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
// add transactions previous value to unspent amount (used to calculate allowed coinbase reward)
var prevOutput = previousOutputs[input.PreviousTxOutputKey].Item3;
txInputValue += prevOutput.Value;
}
for (var outputIndex = 0; outputIndex < tx.Outputs.Length; outputIndex++)
{
// remove transactions spend value from unspent amount (used to calculate allowed coinbase reward)
var output = tx.Outputs[outputIndex];
txOutputValue += output.Value;
}
// ensure that amount being output from transaction isn't greater than amount being input
if (txOutputValue > txInputValue)
{
throw new ValidationException("Failing tx {0}: Transaction output value is greater than input value".Format2(tx.Hash.ToHexNumberString()));
}
// calculate unspent value
unspentValue = (long)(txInputValue - txOutputValue);
// sanity check
if (unspentValue < 0)
{
throw new ValidationException();
}
// all validation has passed
}
public MainnetRules(CacheContext cacheContext)
{
this._cacheContext = cacheContext;
this._highestTarget = UInt256.Parse("00000000FFFF0000000000000000000000000000000000000000000000000000", NumberStyles.HexNumber);
this._genesisBlock =
new Block
(
header: new BlockHeader
(
version: 1,
previousBlock: 0,
merkleRoot: UInt256.Parse("4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b", NumberStyles.HexNumber),
time: 1231006505,
bits: 486604799,
nonce: 2083236893
),
transactions: ImmutableArray.Create
(
new Transaction
(
version: 1,
inputs: ImmutableArray.Create
(
new TxInput
(
previousTxOutputKey: new TxOutputKey
(
txHash: 0,
txOutputIndex: 0xFFFFFFFF
),
scriptSignature: ImmutableArray.Create<byte>
(
0x04, 0xFF, 0xFF, 0x00, 0x1D, 0x01, 0x04, 0x45, 0x54, 0x68, 0x65, 0x20, 0x54, 0x69, 0x6D, 0x65,
0x73, 0x20, 0x30, 0x33, 0x2F, 0x4A, 0x61, 0x6E, 0x2F, 0x32, 0x30, 0x30, 0x39, 0x20, 0x43, 0x68,
0x61, 0x6E, 0x63, 0x65, 0x6C, 0x6C, 0x6F, 0x72, 0x20, 0x6F, 0x6E, 0x20, 0x62, 0x72, 0x69, 0x6E,
0x6B, 0x20, 0x6F, 0x66, 0x20, 0x73, 0x65, 0x63, 0x6F, 0x6E, 0x64, 0x20, 0x62, 0x61, 0x69, 0x6C,
0x6F, 0x75, 0x74, 0x20, 0x66, 0x6F, 0x72, 0x20, 0x62, 0x61, 0x6E, 0x6B, 0x73
),
sequence: 0xFFFFFFFF
)
),
outputs: ImmutableArray.Create
(
new TxOutput
(
value: 50 * SATOSHI_PER_BTC,
scriptPublicKey: ImmutableArray.Create<byte>
(
0x41, 0x04, 0x67, 0x8A, 0xFD, 0xB0, 0xFE, 0x55, 0x48, 0x27, 0x19, 0x67, 0xF1, 0xA6, 0x71, 0x30,
0xB7, 0x10, 0x5C, 0xD6, 0xA8, 0x28, 0xE0, 0x39, 0x09, 0xA6, 0x79, 0x62, 0xE0, 0xEA, 0x1F, 0x61,
0xDE, 0xB6, 0x49, 0xF6, 0xBC, 0x3F, 0x4C, 0xEF, 0x38, 0xC4, 0xF3, 0x55, 0x04, 0xE5, 0x1E, 0xC1,
0x12, 0xDE, 0x5C, 0x38, 0x4D, 0xF7, 0xBA, 0x0B, 0x8D, 0x57, 0x8A, 0x4C, 0x70, 0x2B, 0x6B, 0xF1,
0x1D, 0x5F, 0xAC
)
)
),
lockTime: 0
)
)
);
this._genesisChainedBlock =
new ChainedBlock
(
blockHash: this._genesisBlock.Hash,
previousBlockHash: this._genesisBlock.Header.PreviousBlock,
height: 0,
totalWork: this._genesisBlock.Header.CalculateWork()
);
this._genesisBlockchain =
new Data.Blockchain
(
blockList: ImmutableList.Create(this._genesisChainedBlock),
blockListHashes: ImmutableHashSet.Create(this._genesisBlock.Hash),
utxo: ImmutableDictionary.Create<UInt256, UnspentTx>() // genesis block coinbase is not included in utxo, it is unspendable
);
}
//TODO utxo needs to be as-at transaction, with regards to a transaction being fully spent and added back in in the same block
public virtual void ValidateTransactionScripts(Block block, ImmutableDictionary<UInt256, UnspentTx> utxo, ImmutableDictionary<UInt256, ImmutableHashSet<int>> newTransactions)
{
if (BypassExecuteScript)
return;
// lookup all previous outputs
var prevOutputMissing = false;
var previousOutputs = new Dictionary<TxOutputKey, Tuple<Transaction, TxInput, int, TxOutput>>();
for (var txIndex = 1; txIndex < block.Transactions.Length; txIndex++)
{
var tx = block.Transactions[txIndex];
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
// find previous transaction
var prevTx = GetPreviousTransaction(block, txIndex, input.PreviousTxOutputKey, utxo, newTransactions);
// find previous transaction output
if (input.PreviousTxOutputKey.TxOutputIndex >= prevTx.Outputs.Length)
throw new ValidationException();
var prevOutput = prevTx.Outputs[input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked()];
previousOutputs.Add(input.PreviousTxOutputKey, Tuple.Create(tx, input, inputIndex, prevOutput));
}
}
if (prevOutputMissing)
{
throw new ValidationException();
}
var exceptions = new ConcurrentBag<Exception>();
var scriptEngine = new ScriptEngine();
Parallel.ForEach(previousOutputs.Values, (tuple, loopState) =>
{
try
{
var tx = tuple.Item1;
var input = tuple.Item2;
var inputIndex = tuple.Item3;
var prevOutput = tuple.Item4;
// create the transaction script from the input and output
var script = input.ScriptSignature.AddRange(prevOutput.ScriptPublicKey);
if (!scriptEngine.VerifyScript(0 /*TODO blockHash*/, 0 /*TODO txIndex*/, prevOutput.ScriptPublicKey.ToArray(), tx, inputIndex, script.ToArray()))
{
exceptions.Add(new ValidationException());
loopState.Break();
}
}
catch (Exception e)
{
exceptions.Add(e);
loopState.Break();
}
});
if (exceptions.Count > 0)
throw new AggregateException(exceptions.ToArray());
}
public Data.Blockchain RollbackBlockchain(Data.Blockchain blockchain, Block block, out List<TxOutputKey> spendOutputs, out List<TxOutputKey> receiveOutputs)
{
if (blockchain.BlockCount == 0 || blockchain.RootBlockHash != block.Hash)
throw new ValidationException();
var newUtxo = RollbackUtxo(blockchain, block, out spendOutputs, out receiveOutputs);
return new Data.Blockchain
(
blockList: blockchain.BlockList.RemoveAt(blockchain.BlockCount - 1),
blockListHashes: blockchain.BlockListHashes.Remove(blockchain.RootBlockHash),
utxo: newUtxo
);
}
private Transaction GetPreviousTransaction(Block block, int txIndex, TxOutputKey prevTxOutputKey, ImmutableDictionary<UInt256, UnspentTx> utxo, ImmutableDictionary<UInt256, ImmutableHashSet<int>> newTransactions)
{
if (newTransactions.ContainsKey(prevTxOutputKey.TxHash))
{
var eligible = newTransactions[prevTxOutputKey.TxHash].Where(x => x < txIndex).ToList();
if (eligible.Count > 0)
{
var max = eligible.Max();
if (max >= block.Transactions.Length)
throw new Exception();
var prevTx1 = block.Transactions[max];
if (prevTx1.Hash != prevTxOutputKey.TxHash)
throw new Exception();
return prevTx1;
}
}
// find previous transaction
if (!utxo.ContainsKey(prevTxOutputKey.TxHash))
throw new MissingDataException(DataType.Transaction, prevTxOutputKey.TxHash);
var prevTxKey = utxo[prevTxOutputKey.TxHash].ToTxKey();
var prevTx2 = this.CacheContext.GetTransaction(prevTxKey);
if (prevTx2.Hash != prevTxOutputKey.TxHash)
throw new Exception();
return prevTx2;
}
private ImmutableDictionary<UInt256, UnspentTx> RollbackUtxo(Data.Blockchain blockchain, Block block, out List<TxOutputKey> spendOutputs, out List<TxOutputKey> receiveOutputs)
{
var blockHeight = blockchain.Height;
var currentUtxo = blockchain.Utxo;
// create builder for prev utxo
var prevUtxoBuilder = currentUtxo.ToBuilder();
spendOutputs = new List<TxOutputKey>();
receiveOutputs = new List<TxOutputKey>();
//TODO apply real coinbase rule
// https://github.com/bitcoin/bitcoin/blob/481d89979457d69da07edd99fba451fd42a47f5c/src/core.h#L219
var coinbaseTx = block.Transactions[0];
for (var outputIndex = 0; outputIndex < coinbaseTx.Outputs.Length; outputIndex++)
{
var txOutputKey = new TxOutputKey(coinbaseTx.Hash, (UInt32)outputIndex);
if (blockHeight > 0)
{
// remove new outputs from the rolled back utxo
if (prevUtxoBuilder.Remove(coinbaseTx.Hash))
{
receiveOutputs.Add(txOutputKey);
}
else
{
// missing transaction output
Debug.WriteLine("Missing transaction at block {0:#,##0}, {1}, tx {2}, output {3}".Format2(blockHeight, block.Hash.ToHexNumberString(), 0, outputIndex));
Debugger.Break();
//TODO throw new Validation();
//TODO this needs to be tracked so that blocks can be rolled back accurately
//TODO track these separately on the blockchain info? gonna be costly to track on every transaction
}
}
}
for (var txIndex = block.Transactions.Length - 1; txIndex >= 1; txIndex--)
{
var tx = block.Transactions[txIndex];
for (var outputIndex = tx.Outputs.Length - 1; outputIndex >= 0; outputIndex--)
{
var output = tx.Outputs[outputIndex];
var txOutputKey = new TxOutputKey(tx.Hash, (UInt32)outputIndex);
//TODO what if a transaction wasn't added to the utxo because it already existed?
//TODO the block would still pass without adding the tx to its utxo, but here it would get rolled back
//TODO maybe a flag bit to track this?
// remove new outputs from the rolled back utxo
if (prevUtxoBuilder.Remove(tx.Hash))
{
receiveOutputs.Add(txOutputKey);
}
else
{
// missing transaction output
Debug.WriteLine("Missing transaction at block {0:#,##0}, {1}, tx {2}, output {3}".Format2(blockHeight, block.Hash.ToHexNumberString(), txIndex, outputIndex));
Debugger.Break();
//TODO throw new Validation();
//TODO this needs to be tracked so that blocks can be rolled back accurately
//TODO track these separately on the blockchain info? gonna be costly to track on every transaction
}
}
for (var inputIndex = tx.Inputs.Length - 1; inputIndex >= 0; inputIndex--)
{
var input = tx.Inputs[inputIndex];
// add spent outputs back into the rolled back utxo
if (prevUtxoBuilder.ContainsKey(input.PreviousTxOutputKey.TxHash))
{
var prevUnspentTx = prevUtxoBuilder[input.PreviousTxOutputKey.TxHash];
// check if output is out of bounds
if (input.PreviousTxOutputKey.TxOutputIndex >= prevUnspentTx.UnspentOutputs.Length)
throw new ValidationException();
// check that output isn't already considered unspent
if (prevUnspentTx.UnspentOutputs[input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked()])
throw new ValidationException();
// mark output as unspent
prevUtxoBuilder[input.PreviousTxOutputKey.TxHash] =
new UnspentTx(prevUnspentTx.BlockHash, prevUnspentTx.TxIndex, prevUnspentTx.TxHash,
prevUnspentTx.UnspentOutputs.Set(input.PreviousTxOutputKey.TxOutputIndex.ToIntChecked(), true));
}
else
{
// fully spent transaction being added back in during roll back
//TODO
throw new NotImplementedException();
}
//TODO
//if (prevUtxoBuilder.Add(input.PreviousTxOutputKey))
//{
// spendOutputs.Add(input.PreviousTxOutputKey);
//}
//else
//{
// // missing transaction output
// Debug.WriteLine("Duplicate transaction at block {0:#,##0}, {1}, tx {2}, input {3}".Format2(blockHeight, block.Hash.ToHexNumberString(), txIndex, inputIndex));
// Debugger.Break();
// //TODO throw new Validation();
// //TODO this needs to be tracked so that blocks can be rolled back accurately
// //TODO track these separately on the blockchain info? gonna be costly to track on every transaction
//}
}
}
return prevUtxoBuilder.ToImmutable();
}
public static long SizeEstimator(Block block)
{
return block.SizeEstimate;
}
private void OnBlock(Block block)
{
//Debug.WriteLine("Received block {0}".Format2(block.Hash));
this.requestedBlocks.TryRemove(block.Hash);
this.blockchainDaemon.CacheContext.BlockCache.CreateValue(block.Hash, block);
Tuple<DateTime, DateTime?> receiveTime;
if (this.requestedBlockTimes.TryGetValue(block.Hash, out receiveTime))
{
if (receiveTime.Item2 == null)
this.requestedBlockTimes[block.Hash] = Tuple.Create(receiveTime.Item1, (DateTime?)DateTime.UtcNow);
this.requestBlocksWorker.NotifyWork();
}
}
public static void EncodeBlock(Stream stream, Block block)
{
using (var writer = new BinaryWriter(stream, Encoding.ASCII, leaveOpen: true))
{
EncodeBlockHeader(stream, block.Header);
writer.EncodeList(block.Transactions, tx => EncodeTransaction(stream, tx));
}
}
