public void TestReplayBlock()
{
using (var simulator = new MainnetSimulator())
{
simulator.AddBlockRange(0, 9999);
simulator.WaitForUpdate();
using (var chainState = simulator.CoreDaemon.GetChainState())
{
Assert.AreEqual(9999, chainState.Chain.Height);
for (var blockHeight = 0; blockHeight <= chainState.Chain.Height; blockHeight++)
{
var blockHash = chainState.Chain.Blocks[blockHeight].Hash;
var expectedTransactions = simulator.BlockProvider.GetBlock(blockHeight).Transactions;
var actualTransactions = BlockReplayer.ReplayBlock(simulator.CoreDaemon.CoreStorage, chainState, blockHash, replayForward: true)
.ToEnumerable().ToList();
CollectionAssert.AreEqual(
expectedTransactions.Select(x => x.Hash).ToList(),
actualTransactions.Select(x => x.Transaction.Hash).ToList(),
$"Transactions differ at block {blockHeight:N0}");
}
}
}
}
private async Task ScanBlock(ICoreStorage coreStorage, IChainState chainState, ChainedHeader scanBlock, bool forward, CancellationToken cancelToken = default(CancellationToken))
{
var replayTxes = BlockReplayer.ReplayBlock(coreStorage, chainState, scanBlock.Hash, forward, cancelToken);
var txScanner = new ActionBlock <ValidatableTx>(
validatableTx =>
{
var tx = validatableTx.Transaction;
var txIndex = validatableTx.Index;
if (!validatableTx.IsCoinbase)
{
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
var prevOutput = validatableTx.PrevTxOutputs[inputIndex];
var prevOutputScriptHash = new UInt256(SHA256Static.ComputeHash(prevOutput.ScriptPublicKey));
var chainPosition = ChainPosition.Fake();
var entryType = forward ? EnumWalletEntryType.Spend : EnumWalletEntryType.UnSpend;
ScanForEntry(chainPosition, entryType, (TxOutput)prevOutput, prevOutputScriptHash);
}
}
for (var outputIndex = 0; outputIndex < tx.Outputs.Length; outputIndex++)
{
var output = tx.Outputs[outputIndex];
var outputScriptHash = new UInt256(SHA256Static.ComputeHash(output.ScriptPublicKey));
var chainPosition = ChainPosition.Fake();
var entryType =
validatableTx.IsCoinbase ?
(forward ? EnumWalletEntryType.Mine : EnumWalletEntryType.UnMine)
: (forward ? EnumWalletEntryType.Receive : EnumWalletEntryType.UnReceieve);
ScanForEntry(chainPosition, entryType, output, outputScriptHash);
}
});
replayTxes.LinkTo(txScanner, new DataflowLinkOptions {
PropagateCompletion = true
});
await txScanner.Completion;
}
public void ReplayBlockExample()
{
// create example core daemon
BlockProvider embeddedBlocks; IStorageManager storageManager;
using (var coreDaemon = CreateExampleDaemon(out embeddedBlocks, out storageManager, maxHeight: 999))
using (embeddedBlocks)
using (storageManager)
{
// start a chain at the genesis block to represent the processed progress
var processedChain = Chain.CreateForGenesisBlock(coreDaemon.ChainParams.GenesisChainedHeader).ToBuilder();
// a dictionary of public key script hashes can be created for any addresses of interest, allowing for quick checking
var scriptHashesOfInterest = new HashSet <UInt256>();
// retrieve a chainstate to replay blocks with
using (var chainState = coreDaemon.GetChainState())
{
// enumerate the steps needed to take the currently processed chain towards the current chainstate
foreach (var pathElement in processedChain.NavigateTowards(chainState.Chain))
{
// retrieve the next block to replay and whether to replay forwards, or backwards for a re-org
var replayForward = pathElement.Item1 > 0;
var replayBlock = pathElement.Item2;
// begin replaying the transactions in the replay block
// if this is a re-org, the transactions will be replayed in reverse block order
var replayTxes = BlockReplayer.ReplayBlock(coreDaemon.CoreStorage, chainState, replayBlock.Hash, replayForward);
// prepare the tx scanner
var txScanner = new ActionBlock <ValidatableTx>(
validatableTx =>
{
// the transaction being replayed
var tx = validatableTx.Transaction;
// the previous tx outputs for each of the replay transaction's inputs
var prevTxOutputs = validatableTx.PrevTxOutputs;
// scan the replay transaction's inputs
if (!validatableTx.IsCoinbase)
{
for (var inputIndex = 0; inputIndex < tx.Inputs.Length; inputIndex++)
{
var input = tx.Inputs[inputIndex];
var inputPrevTxOutput = validatableTx.PrevTxOutputs[inputIndex];
// check if the input's previous transaction output is of interest
var inputPrevTxOutputPublicScriptHash = new UInt256(SHA256Static.ComputeHash(inputPrevTxOutput.ScriptPublicKey));
if (scriptHashesOfInterest.Contains(inputPrevTxOutputPublicScriptHash))
{
if (replayForward)
{ /* An output for an address of interest is being spent. */
}
else
{ /* An output for an address of interest is being "unspent", on re-org. */
}
}
}
}
// scan the replay transaction's outputs
for (var outputIndex = 0; outputIndex < tx.Outputs.Length; outputIndex++)
{
var output = tx.Outputs[outputIndex];
// check if the output is of interest
var outputPublicScriptHash = new UInt256(SHA256Static.ComputeHash(output.ScriptPublicKey));
if (scriptHashesOfInterest.Contains(outputPublicScriptHash))
{
if (replayForward)
{ /* An output for an address of interest is being minted. */
}
else
{ /* An output for an address of interest is being "unminted", on re-org. */
}
}
}
});
// hook up and wait for the tx scanner
replayTxes.LinkTo(txScanner, new DataflowLinkOptions {
PropagateCompletion = true
});
txScanner.Completion.Wait();
// a wallet would now commit its progress
/*
* walletDatabase.CurrentBlock = replayBlock.Hash;
* walletDatabase.Commit();
*/
// TODO: after successfully committing, a wallet would notify CoreDaemon of its current progress
// TODO: CoreDaemon will use this information in order to determine how far in the current chainstate it is safe to prune
// TODO: with this in place, if a wallet suffers a failure to commit it can just replay the block
// TODO: wallets can also remain disconnected from CoreDaemon, and just replay blocks to catch up when they are reconnected
// update the processed chain so that the next step towards the current chainstate can be taken
if (replayForward)
{
processedChain.AddBlock(replayBlock);
}
else
{
processedChain.RemoveBlock(replayBlock);
}
}
}
logger.Info("Processed chain height: {0:N0}", processedChain.Height);
}
}
public void TestReplayBlockRollback()
{
using (var daemon = new TestDaemon())
{
// create a new keypair to spend to
var toKeyPair = daemon.TxManager.CreateKeyPair();
var toPrivateKey = toKeyPair.Item1;
var toPublicKey = toKeyPair.Item2;
// add block 1
var block0 = daemon.GenesisBlock;
var block1 = daemon.MineAndAddEmptyBlock();
// add some blocks so coinbase is mature to spend
Block lastBlock = null;
for (var i = 0; i < 100; i++)
{
lastBlock = daemon.MineAndAddEmptyBlock();
}
// add block 2, spending from block 1
var spendTx1 = daemon.TxManager.CreateSpendTransaction(block1.Transactions[0], 0, (byte)ScriptHashType.SIGHASH_ALL, block1.Transactions[0].OutputValue(), daemon.CoinbasePrivateKey, daemon.CoinbasePublicKey, toPublicKey);
var block2Unmined = daemon.CreateEmptyBlock(lastBlock.Hash)
.CreateWithAddedTransactions(spendTx1);
var block2 = daemon.MineAndAddBlock(block2Unmined);
// add some blocks so coinbase is mature to spend
for (var i = 0; i < 100; i++)
{
lastBlock = daemon.MineAndAddEmptyBlock();
}
// add block 3, spending from block 2
var spendTx2 = daemon.TxManager.CreateSpendTransaction(block2.Transactions[1], 0, (byte)ScriptHashType.SIGHASH_ALL, block2.Transactions[1].OutputValue(), toPrivateKey, toPublicKey, toPublicKey);
var block3Unmined = daemon.CreateEmptyBlock(lastBlock.Hash)
.CreateWithAddedTransactions(spendTx2);
var block3 = daemon.MineAndAddBlock(block3Unmined);
// replay all blocks up to block 3
daemon.WaitForUpdate();
using (var chainState = daemon.CoreDaemon.GetChainState())
{
Assert.AreEqual(203, chainState.Chain.Height);
var replayTransactions = new List <ValidatableTx>();
foreach (var blockHash in chainState.Chain.Blocks.Select(x => x.Hash))
{
replayTransactions.AddRange(BlockReplayer.ReplayBlock(daemon.CoreStorage, chainState, blockHash, replayForward: true)
.ToEnumerable());
}
// verify all transactions were replayed
Assert.AreEqual(206, replayTransactions.Count);
Assert.AreEqual(block0.Transactions[0].Hash, replayTransactions[0].Transaction.Hash);
Assert.AreEqual(block1.Transactions[0].Hash, replayTransactions[1].Transaction.Hash);
Assert.AreEqual(block2.Transactions[0].Hash, replayTransactions[102].Transaction.Hash);
Assert.AreEqual(block2.Transactions[1].Hash, replayTransactions[103].Transaction.Hash);
Assert.AreEqual(block3.Transactions[0].Hash, replayTransactions[204].Transaction.Hash);
Assert.AreEqual(block3.Transactions[1].Hash, replayTransactions[205].Transaction.Hash);
}
// mark block 2 invalid, it will be rolled back
daemon.CoreStorage.MarkBlockInvalid(block2.Hash, daemon.CoreDaemon.TargetChain);
daemon.WaitForUpdate();
// replay rollback of block 3
using (var chainState = daemon.CoreDaemon.GetChainState())
{
Assert.AreEqual(101, chainState.Chain.Height);
var replayTransactions = new List <ValidatableTx>(
BlockReplayer.ReplayBlock(daemon.CoreStorage, chainState, block3.Hash, replayForward: false)
.ToEnumerable());
// verify transactions were replayed
Assert.AreEqual(2, replayTransactions.Count);
Assert.AreEqual(block3.Transactions[1].Hash, replayTransactions[0].Transaction.Hash);
Assert.AreEqual(block3.Transactions[0].Hash, replayTransactions[1].Transaction.Hash);
// verify correct previous output was replayed (block 3 tx 1 spent block 2 tx 1)
Assert.AreEqual(1, replayTransactions[0].PrevTxOutputs.Length);
CollectionAssert.AreEqual(block2.Transactions[1].Outputs[0].ScriptPublicKey, replayTransactions[0].PrevTxOutputs[0].ScriptPublicKey);
// verify correct previous output was replayed (block 3 tx 0 spends nothing, coinbase)
Assert.AreEqual(0, replayTransactions[1].PrevTxOutputs.Length);
}
// replay rollback of block 2
using (var chainState = daemon.CoreDaemon.GetChainState())
{
Assert.AreEqual(101, chainState.Chain.Height);
var replayTransactions = new List <ValidatableTx>(
BlockReplayer.ReplayBlock(daemon.CoreStorage, chainState, block2.Hash, replayForward: false)
.ToEnumerable());
// verify transactions were replayed
Assert.AreEqual(2, replayTransactions.Count);
Assert.AreEqual(block2.Transactions[1].Hash, replayTransactions[0].Transaction.Hash);
Assert.AreEqual(block2.Transactions[0].Hash, replayTransactions[1].Transaction.Hash);
// verify correct previous output was replayed (block 2 tx 1 spent block 1 tx 0)
Assert.AreEqual(1, replayTransactions[0].PrevTxOutputs.Length);
CollectionAssert.AreEqual(block1.Transactions[0].Outputs[0].ScriptPublicKey, replayTransactions[0].PrevTxOutputs[0].ScriptPublicKey);
// verify correct previous output was replayed (block 2 tx 0 spends nothing, coinbase)
Assert.AreEqual(0, replayTransactions[1].PrevTxOutputs.Length);
}
}
}
