private bool ConnectBlock(CBlockStoreItem cursor, ref CBlock block, bool fJustCheck = false)
{
// Check it again in case a previous version let a bad block in, but skip BlockSig checking
if (!block.CheckBlock(!fJustCheck, !fJustCheck, false))
{
return false; // Invalid block found.
}
bool fScriptChecks = cursor.nHeight >= HashCheckpoints.TotalBlocksEstimate;
var scriptFlags = scriptflag.SCRIPT_VERIFY_NOCACHE | scriptflag.SCRIPT_VERIFY_P2SH;
long nFees = 0;
long nValueIn = 0;
long nValueOut = 0;
uint nSigOps = 0;
var queuedMerkleNodes = new Dictionary<uint256, CMerkleNode>();
var queuedOutputs = new Dictionary<COutPoint, TxOutItem>();
for (var nTx = 0; nTx < block.vtx.Length; nTx++)
{
var tx = block.vtx[nTx];
var hashTx = tx.Hash;
if (!queuedMerkleNodes.ContainsKey(hashTx))
{
var nTxPos = cursor.nBlockPos + block.GetTxOffset(nTx);
var mNode = new CMerkleNode(cursor.ItemID, nTxPos, tx);
queuedMerkleNodes.Add(hashTx, mNode);
}
Dictionary<COutPoint, TxOutItem> txouts;
if (GetOutputs(hashTx, out txouts))
{
// Do not allow blocks that contain transactions which 'overwrite' older transactions,
// unless those are already completely spent.
return false;
}
nSigOps += tx.LegacySigOpCount;
if (nSigOps > CBlock.nMaxSigOps)
{
return false; // too many sigops
}
var inputs = new Dictionary<COutPoint, TxOutItem>();
if (tx.IsCoinBase)
{
nValueOut += tx.nValueOut;
}
else
{
bool Invalid;
if (!FetchInputs(ref tx, ref queuedOutputs, ref inputs, true, out Invalid))
{
return false; // Unable to fetch some inputs.
}
// Add in sigops done by pay-to-script-hash inputs;
// this is to prevent a "rogue miner" from creating
// an incredibly-expensive-to-validate block.
nSigOps += tx.GetP2SHSigOpCount(ref inputs);
if (nSigOps > CBlock.nMaxSigOps)
{
return false; // too many sigops
}
long nTxValueIn = tx.GetValueIn(ref inputs);
long nTxValueOut = tx.nValueOut;
nValueIn += nTxValueIn;
nValueOut += nTxValueOut;
if (!tx.IsCoinStake)
{
nFees += nTxValueIn - nTxValueOut;
}
if (!ConnectInputs(ref tx, ref inputs, ref queuedOutputs, ref cursor, true, fScriptChecks, scriptFlags))
{
return false;
}
}
for (var i = 0u; i < tx.vout.Length; i++)
{
var outKey = new COutPoint(hashTx, i);
var outData = new TxOutItem()
{
nMerkleNodeID = -1,
nValue = tx.vout[i].nValue,
scriptPubKey = tx.vout[i].scriptPubKey,
IsSpent = false,
nOut = i
};
queuedOutputs.Add(outKey, outData);
}
}
if (!block.IsProofOfStake)
{
long nBlockReward = CBlock.GetProofOfWorkReward(cursor.nBits, nFees);
// Check coinbase reward
if (block.vtx[0].nValueOut > nBlockReward)
{
return false; // coinbase reward exceeded
}
}
cursor.nMint = nValueOut - nValueIn + nFees;
cursor.nMoneySupply = (cursor.prev != null ? cursor.prev.nMoneySupply : 0) + nValueOut - nValueIn;
if (!UpdateDBCursor(ref cursor))
{
return false; // Unable to commit changes
}
if (fJustCheck)
{
return true;
}
// Flush merkle nodes.
var savedMerkleNodes = new Dictionary<uint256, CMerkleNode>();
foreach (var merklePair in queuedMerkleNodes)
{
var merkleNode = merklePair.Value;
if (!SaveMerkleNode(ref merkleNode))
{
// Unable to save merkle tree cursor.
return false;
}
savedMerkleNodes.Add(merklePair.Key, merkleNode);
}
// Write queued transaction changes
var newOutpointItems = new List<TxOutItem>();
var updatedOutpointItems = new List<TxOutItem>();
foreach (var outPair in queuedOutputs)
{
var outItem = outPair.Value;
if (outItem.nMerkleNodeID == -1)
{
// This outpoint doesn't exist yet, adding to insert list.
outItem.nMerkleNodeID = savedMerkleNodes[outPair.Key.hash].nMerkleNodeID;
newOutpointItems.Add(outItem);
}
else
{
// This outpount already exists, adding to update list.
updatedOutpointItems.Add(outItem);
}
}
if (updatedOutpointItems.Count != 0 && !UpdateOutpoints(ref updatedOutpointItems))
{
return false; // Unable to update outpoints
}
if (newOutpointItems.Count != 0 && !InsertOutpoints(ref newOutpointItems))
{
return false; // Unable to insert outpoints
}
return true;
}
/// <summary>
/// Update cursor in memory and on disk.
/// </summary>
/// <param name="cursor">Block cursor</param>
/// <returns>Result</returns>
public bool UpdateMapCursor(CBlockStoreItem cursor)
{
var original = blockMap[cursor.Hash];
return blockMap.TryUpdate(cursor.Hash, cursor, original);
}
private bool AddItemToIndex(ref CBlockStoreItem newCursor, ref CBlock block)
{
uint256 blockHash = newCursor.Hash;
if (blockMap.ContainsKey(blockHash))
{
// Already have this block.
return false;
}
// Begin transaction
dbConn.BeginTransaction();
// Compute chain trust score
newCursor.nChainTrust = (newCursor.prev != null ? newCursor.prev.nChainTrust : 0) + newCursor.nBlockTrust;
if (!newCursor.SetStakeEntropyBit(Entropy.GetStakeEntropyBit(newCursor.nHeight, blockHash)))
{
return false; // SetStakeEntropyBit() failed
}
// compute stake modifier
long nStakeModifier = 0;
bool fGeneratedStakeModifier = false;
if (!StakeModifier.ComputeNextStakeModifier(ref newCursor, ref nStakeModifier, ref fGeneratedStakeModifier))
{
return false; // ComputeNextStakeModifier() failed
}
newCursor.SetStakeModifier(nStakeModifier, fGeneratedStakeModifier);
newCursor.nStakeModifierChecksum = StakeModifier.GetModifierChecksum(newCursor);
if (!ModifierCheckpoints.Verify(newCursor.nHeight, newCursor.nStakeModifierChecksum))
{
return false; // Stake modifier checkpoints mismatch
}
// Add to index
if (block.IsProofOfStake)
{
newCursor.SetProofOfStake();
newCursor.prevoutStake = block.vtx[1].vin[0].prevout;
newCursor.nStakeTime = block.vtx[1].nTime;
// Save proof-of-stake hash value
uint256 hashProofOfStake;
if (!GetProofOfStakeHash(ref blockHash, out hashProofOfStake))
{
return false; // hashProofOfStake not found
}
newCursor.hashProofOfStake = hashProofOfStake;
}
if (!newCursor.WriteToFile(ref fStreamReadWrite, ref block))
{
return false;
}
if (dbConn.Insert(newCursor) == 0)
{
return false; // Insert failed
}
// Get last RowID.
newCursor.ItemID = dbPlatform.SQLiteApi.LastInsertRowid(dbConn.Handle);
if (!blockMap.TryAdd(blockHash, newCursor))
{
return false; // blockMap add failed
}
if (newCursor.nChainTrust > ChainParams.nBestChainTrust)
{
// New best chain
if (!SetBestChain(ref newCursor))
{
return false; // SetBestChain failed.
}
}
// Commit transaction
dbConn.Commit();
return true;
}
/// <summary>
/// Get merkle node cursor by output metadata.
/// </summary>
/// <param name="item">Output metadata object</param>
/// <returns>Merkle node cursor or null</returns>
public CMerkleNode GetMerkleCursor(TxOutItem item, out CBlockStoreItem blockCursor)
{
blockCursor = null;
// Trying to get cursor from the database.
var QueryMerkleCursor = dbConn.Query<CMerkleNode>("select * from [MerkleNodes] where [nMerkleNodeID] = ?", item.nMerkleNodeID);
if (QueryMerkleCursor.Count == 1)
{
var merkleNode = QueryMerkleCursor[0];
// Search for block
var results = blockMap.Where(x => x.Value.ItemID == merkleNode.nParentBlockID).Select(x => x.Value).ToArray();
blockCursor = results[0];
return merkleNode;
}
// Nothing found.
return null;
}
/// <summary>
/// Update cursor record in database.
/// </summary>
/// <param name="cursor">Block cursor object</param>
/// <returns>Result</returns>
public bool UpdateDBCursor(ref CBlockStoreItem cursor)
{
return dbConn.Update(cursor) != 0;
}
/// <summary>
/// Set new top node or current best chain.
/// </summary>
/// <param name="cursor"></param>
/// <returns></returns>
private bool UpdateTopChain(CBlockStoreItem cursor)
{
ChainParams.HashBestChain = cursor.Hash;
ChainParams.nBestChainTrust = cursor.nChainTrust;
ChainParams.nBestHeight = cursor.nHeight;
return dbConn.Update(ChainParams) != 0;
}
public bool AcceptBlock(ref CBlock block)
{
uint256 nHash = block.header.Hash;
if (blockMap.ContainsKey(nHash))
{
// Already have this block.
return false;
}
CBlockStoreItem prevBlockCursor;
if (!blockMap.TryGetValue(block.header.prevHash, out prevBlockCursor))
{
// Unable to get the cursor.
return false;
}
var prevBlockHeader = prevBlockCursor.BlockHeader;
uint nHeight = prevBlockCursor.nHeight + 1;
// Check timestamp against prev
if (NetInfo.FutureDrift(block.header.nTime) < prevBlockHeader.nTime)
{
// block's timestamp is too early
return false;
}
// Check that all transactions are finalized
foreach (var tx in block.vtx)
{
if (!tx.IsFinal(nHeight, block.header.nTime))
{
return false;
}
}
// Check that the block chain matches the known block chain up to a checkpoint
if (!HashCheckpoints.Verify(nHeight, nHash))
{
return false; // rejected by checkpoint lock-in
}
// Enforce rule that the coinbase starts with serialized block height
var expect = new CScript();
expect.AddNumber((int)nHeight);
byte[] expectBytes = expect;
byte[] scriptSig = block.vtx[0].vin[0].scriptSig;
if (!expectBytes.SequenceEqual(scriptSig.Take(expectBytes.Length)))
{
return false; // coinbase doesn't start with serialized height.
}
// Write block to file.
var newCursor = new CBlockStoreItem()
{
nHeight = nHeight,
};
newCursor.FillHeader(block.header);
if (!AddItemToIndex(ref newCursor, ref block))
{
dbConn.Rollback();
return false;
}
return true;
}
private bool SetBestChain(ref CBlockStoreItem cursor)
{
uint256 hashBlock = cursor.Hash;
if (genesisBlockCursor == null && hashBlock == NetInfo.nHashGenesisBlock)
{
genesisBlockCursor = cursor;
}
else if (ChainParams.nHashBestChain == (uint256)cursor.prevHash)
{
if (!SetBestChainInner(cursor))
{
return false;
}
}
else
{
// the first block in the new chain that will cause it to become the new best chain
var cursorIntermediate = cursor;
// list of blocks that need to be connected afterwards
var secondary = new List<CBlockStoreItem>();
// Reorganize is costly in terms of db load, as it works in a single db transaction.
// Try to limit how much needs to be done inside
while (cursorIntermediate.prev != null && cursorIntermediate.prev.nChainTrust > bestBlockCursor.nChainTrust)
{
secondary.Add(cursorIntermediate);
cursorIntermediate = cursorIntermediate.prev;
}
// Switch to new best branch
if (!Reorganize(cursorIntermediate))
{
InvalidChainFound(cursor);
return false; // reorganize failed
}
// Connect further blocks
foreach (var currentCursor in secondary)
{
CBlock block;
if (!currentCursor.ReadFromFile(ref fStreamReadWrite, out block))
{
// ReadFromDisk failed
break;
}
// errors now are not fatal, we still did a reorganisation to a new chain in a valid way
if (!SetBestChainInner(currentCursor))
{
break;
}
}
}
bestBlockCursor = cursor;
nTimeBestReceived = Interop.GetTime();
nTransactionsUpdated++;
if (!UpdateTopChain(cursor))
{
return false; // unable to set top chain node.
}
return true;
}
private bool SetBestChainInner(CBlockStoreItem cursor)
{
uint256 hash = cursor.Hash;
CBlock block;
if (!cursor.ReadFromFile(ref fStreamReadWrite, out block))
{
return false; // Unable to read block from file.
}
// Adding to current best branch
if (!ConnectBlock(cursor, ref block) || !UpdateTopChain(cursor))
{
InvalidChainFound(cursor);
return false;
}
// Add to current best branch
var prevCursor = cursor.prev;
prevCursor.next = cursor;
if (!UpdateDBCursor(ref prevCursor))
{
return false; // unable to update
}
// Delete redundant memory transactions
foreach (var tx in block.vtx)
{
CTransaction dummy;
mapUnconfirmedTx.TryRemove(tx.Hash, out dummy);
}
return true;
}
/// <summary>
/// Init the block storage manager.
/// </summary>
/// <param name="IndexDB">Path to index database</param>
/// <param name="BlockFile">Path to block file</param>
public CBlockStore(string IndexDB = "blockstore.dat", string BlockFile = "blk0001.dat")
{
strDbFile = IndexDB;
strBlockFile = BlockFile;
bool firstInit = !File.Exists(strDbFile);
dbPlatform = new SQLitePlatformGeneric();
dbConn = new SQLiteConnection(dbPlatform, strDbFile);
fStreamReadWrite = File.Open(strBlockFile, FileMode.OpenOrCreate, FileAccess.ReadWrite);
Instance = this;
if (firstInit)
{
lock (LockObj)
{
// Create tables
dbConn.CreateTable<CBlockStoreItem>(CreateFlags.AutoIncPK);
dbConn.CreateTable<CMerkleNode>(CreateFlags.AutoIncPK);
dbConn.CreateTable<TxOutItem>(CreateFlags.ImplicitPK);
dbConn.CreateTable<ChainState>(CreateFlags.AutoIncPK);
ChainParams = new ChainState()
{
nBestChainTrust = 0,
nBestHeight = 0,
nHashBestChain = 0
};
dbConn.Insert(ChainParams);
var genesisBlock = new CBlock(
Interop.HexToArray(
"01000000" + // nVersion=1
"0000000000000000000000000000000000000000000000000000000000000000" + // prevhash is zero
"7b0502ad2f9f675528183f83d6385794fbcaa914e6d385c6cb1d866a3b3bb34c" + // merkle root
"398e1151" + // nTime=1360105017
"ffff0f1e" + // nBits=0x1e0fffff
"d3091800" + // nNonce=1575379
"01" + // nTxCount=1
"01000000" + // nVersion=1
"398e1151" + // nTime=1360105017
"01" + // nInputs=1
"0000000000000000000000000000000000000000000000000000000000000000" + // input txid is zero
"ffffffff" + // n=uint.maxValue
"4d" + // scriptSigLen=77
"04ffff001d020f274468747470733a2f2f626974636f696e74616c6b2e6f72672f696e6465782e7068703f746f7069633d3133343137392e6d736731353032313936236d736731353032313936" + // scriptSig
"ffffffff" + // nSequence=uint.maxValue
"01" + // nOutputs=1
"0000000000000000" + // nValue=0
"00" + // scriptPubkeyLen=0
"00000000" + // nLockTime=0
"00" // sigLen=0
));
// Write block to file.
var rootCursor = new CBlockStoreItem()
{
nHeight = 0
};
rootCursor.FillHeader(genesisBlock.header);
if (!AddItemToIndex(ref rootCursor, ref genesisBlock))
{
throw new Exception("Unable to write genesis block");
}
}
}
else
{
var blockTreeItems = dbConn.Query<CBlockStoreItem>("select * from [BlockStorage] order by [ItemId] asc");
// Init list of block items
foreach (var item in blockTreeItems)
{
item.nStakeModifierChecksum = StakeModifier.GetModifierChecksum(item);
blockMap.TryAdd(item.Hash, item);
if (item.IsProofOfStake)
{
// build mapStakeSeen
mapStakeSeen.TryAdd(item.prevoutStake, item.nStakeTime);
}
}
// Load data about the top node.
ChainParams = dbConn.Table<ChainState>().First();
genesisBlockCursor = dbConn.Query<CBlockStoreItem>("select * from [BlockStorage] where [Hash] = ?", (byte[])NetInfo.nHashGenesisBlock).First();
bestBlockCursor = dbConn.Query<CBlockStoreItem>("select * from [BlockStorage] where [Hash] = ?", ChainParams.HashBestChain).First();
}
}
private bool Reorganize(CBlockStoreItem cursorIntermediate)
{
// Find the fork
var fork = bestBlockCursor;
var longer = cursorIntermediate;
while (fork.ItemID != longer.ItemID)
{
while (longer.nHeight > fork.nHeight)
{
if ((longer = longer.prev) == null)
{
return false; // longer.prev is null
}
}
if (fork.ItemID == longer.ItemID)
{
break;
}
if ((fork = fork.prev) == null)
{
return false; // fork.prev is null
}
}
// List of what to disconnect
var disconnect = new List<CBlockStoreItem>();
for (var cursor = bestBlockCursor; cursor.ItemID != fork.ItemID; cursor = cursor.prev)
{
disconnect.Add(cursor);
}
// List of what to connect
var connect = new List<CBlockStoreItem>();
for (var cursor = cursorIntermediate; cursor.ItemID != fork.ItemID; cursor = cursor.prev)
{
connect.Add(cursor);
}
connect.Reverse();
// Disconnect shorter branch
var txResurrect = new List<CTransaction>();
foreach (var blockCursor in disconnect)
{
CBlock block;
if (!blockCursor.ReadFromFile(ref fStreamReadWrite, out block))
{
return false; // ReadFromFile for disconnect failed.
}
if (!DisconnectBlock(blockCursor, ref block))
{
return false; // DisconnectBlock failed.
}
// Queue memory transactions to resurrect
foreach (var tx in block.vtx)
{
if (!tx.IsCoinBase && !tx.IsCoinStake)
{
txResurrect.Add(tx);
}
}
}
// Connect longer branch
var txDelete = new List<CTransaction>();
foreach (var cursor in connect)
{
CBlock block;
if (!cursor.ReadFromFile(ref fStreamReadWrite, out block))
{
return false; // ReadFromDisk for connect failed
}
if (!ConnectBlock(cursor, ref block))
{
// Invalid block
return false; // ConnectBlock failed
}
// Queue memory transactions to delete
foreach (var tx in block.vtx)
{
txDelete.Add(tx);
}
}
if (!UpdateTopChain(cursorIntermediate))
{
return false; // UpdateTopChain failed
}
// Resurrect memory transactions that were in the disconnected branch
foreach (var tx in txResurrect)
{
mapUnconfirmedTx.TryAdd(tx.Hash, tx);
}
// Delete redundant memory transactions that are in the connected branch
foreach (var tx in txDelete)
{
CTransaction dummy;
mapUnconfirmedTx.TryRemove(tx.Hash, out dummy);
}
return true; // Done
}
private void InvalidChainFound(CBlockStoreItem cursor)
{
throw new NotImplementedException();
}
private bool DisconnectBlock(CBlockStoreItem blockCursor, ref CBlock block)
{
throw new NotImplementedException();
}
private bool ConnectInputs(ref CTransaction tx, ref Dictionary<COutPoint, TxOutItem> inputs, ref Dictionary<COutPoint, TxOutItem> queued, ref CBlockStoreItem cursorBlock, bool fBlock, bool fScriptChecks, scriptflag scriptFlags)
{
// Take over previous transactions' spent items
// fBlock is true when this is called from AcceptBlock when a new best-block is added to the blockchain
if (!tx.IsCoinBase)
{
long nValueIn = 0;
long nFees = 0;
for (uint i = 0; i < tx.vin.Length; i++)
{
var prevout = tx.vin[i].prevout;
Contract.Assert(inputs.ContainsKey(prevout));
var input = inputs[prevout];
CBlockStoreItem parentBlockCursor;
if (input.nMerkleNodeID == -1)
{
// This input seems as is confirmed by the same block.
if (!queued.ContainsKey(prevout))
{
return false; // No such output has been queued by this block.
}
// TODO: Ensure that neither coinbase nor coinstake outputs are
// available for spending in the generation block.
}
else
{
// This input has been confirmed by one of the earlier accepted blocks.
var merkleItem = GetMerkleCursor(input, out parentBlockCursor);
if (merkleItem == null)
{
return false; // Unable to find merkle node
}
// If prev is coinbase or coinstake, check that it's matured
if (merkleItem.IsCoinBase || merkleItem.IsCoinStake)
{
if (cursorBlock.nHeight - parentBlockCursor.nHeight < NetInfo.nGeneratedMaturity)
{
return false; // tried to spend non-matured generation input.
}
}
// check transaction timestamp
if (merkleItem.nTime > tx.nTime)
{
return false; // transaction timestamp earlier than input transaction
}
}
// Check for negative or overflow input values
nValueIn += input.nValue;
if (!CTransaction.MoneyRange(input.nValue) || !CTransaction.MoneyRange(nValueIn))
{
return false; // txin values out of range
}
}
// The first loop above does all the inexpensive checks.
// Only if ALL inputs pass do we perform expensive ECDSA signature checks.
// Helps prevent CPU exhaustion attacks.
for (int i = 0; i < tx.vin.Length; i++)
{
var prevout = tx.vin[i].prevout;
Contract.Assert(inputs.ContainsKey(prevout));
var input = inputs[prevout];
// Check for conflicts (double-spend)
if (input.IsSpent)
{
return false;
}
// Skip ECDSA signature verification when connecting blocks (fBlock=true)
// before the last blockchain checkpoint. This is safe because block merkle hashes are
// still computed and checked, and any change will be caught at the next checkpoint.
if (fScriptChecks)
{
// Verify signature
if (!ScriptCode.VerifyScript(tx.vin[i].scriptSig, input.scriptPubKey, tx, i, (int)scriptflag.SCRIPT_VERIFY_P2SH, 0))
{
return false; // VerifyScript failed.
}
}
// Mark outpoint as spent
input.IsSpent = true;
inputs[prevout] = input;
// Write back
if (fBlock)
{
if (input.nMerkleNodeID != -1)
{
// Input has been confirmed earlier.
queued.Add(prevout, input);
}
else
{
// Input has been confirmed by current block.
queued[prevout] = input;
}
}
}
if (tx.IsCoinStake)
{
if (HashCheckpoints.LastCheckpointTime < tx.nTime)
{
// Coin stake tx earns reward instead of paying fee
long nCoinAge;
if (!tx.GetCoinAge(ref inputs, out nCoinAge))
{
return false; // unable to get coin age for coinstake
}
long nReward = tx.nValueOut - nValueIn;
long nCalculatedReward = CBlock.GetProofOfStakeReward(nCoinAge, cursorBlock.nBits, tx.nTime) - tx.GetMinFee(1, false, CTransaction.MinFeeMode.GMF_BLOCK) + CTransaction.nCent;
if (nReward > nCalculatedReward)
{
return false; // coinstake pays too much
}
}
}
else
{
if (nValueIn < tx.nValueOut)
{
return false; // value in < value out
}
// Tally transaction fees
long nTxFee = nValueIn - tx.nValueOut;
if (nTxFee < 0)
{
return false; // nTxFee < 0
}
nFees += nTxFee;
if (!CTransaction.MoneyRange(nFees))
{
return false; // nFees out of range
}
}
}
return true;
}