// FIXME it's very dangerous because replacing Id means
// ALL blocks (referenced by MineBlock(), etc.) will be changed.
// we need to add a synchronization mechanism to handle this correctly.
internal void Swap(BlockChain <T> other, bool render)
{
// Finds the branch point.
Block <T> topmostCommon = null;
if (render && !(Tip is null || other.Tip is null))
{
long shorterHeight =
Math.Min(this.LongCount(), other.LongCount()) - 1;
for (
Block <T> t = this[shorterHeight], o = other[shorterHeight];
t.PreviousHash is HashDigest <SHA256> tp &&
o.PreviousHash is HashDigest <SHA256> op;
t = Blocks[tp], o = other.Blocks[op]
)
{
if (t.Equals(o))
{
topmostCommon = t;
break;
}
}
}
if (render)
{
// Unrender stale actions.
for (
Block <T> b = Tip;
!(b is null) && b.Index > (topmostCommon?.Index ?? -1) &&
b.PreviousHash is HashDigest <SHA256> ph;
b = Blocks[ph]
)
{
List <ActionEvaluation> evaluations = b.EvaluateActionsPerTx(a =>
GetStates(new[] { a }, b.PreviousHash).GetValueOrDefault(a))
.Select(te => te.Item2).ToList();
if (Policy.BlockAction is IAction)
{
evaluations.Add(EvaluateBlockAction(b, evaluations));
}
evaluations.Reverse();
foreach (var evaluation in evaluations)
{
evaluation.Action.Unrender(
evaluation.InputContext,
evaluation.OutputStates
);
}
}
}
try
{
_rwlock.EnterWriteLock();
var tipChangedEventArgs = new TipChangedEventArgs
{
PreviousHash = Tip?.Hash,
PreviousIndex = Tip?.Index,
Hash = other.Tip.Hash,
Index = other.Tip.Index,
};
Guid obsoleteId = Id;
Id = other.Id;
Store.SetCanonicalChainId(Id);
Blocks = new BlockSet <T>(Store);
TipChanged?.Invoke(this, tipChangedEventArgs);
Transactions = new TransactionSet <T>(Store);
Store.DeleteChainId(obsoleteId);
}
finally
{
_rwlock.ExitWriteLock();
}
if (render)
{
// Render actions that had been behind.
IEnumerable <Block <T> > blocksToRender =
topmostCommon is Block <T> branchPoint
? this.SkipWhile(b => b.Index <= branchPoint.Index)
: this;
foreach (Block <T> b in blocksToRender)
{
List <ActionEvaluation> evaluations = b.EvaluateActionsPerTx(a =>
GetStates(new[] { a }, b.PreviousHash).GetValueOrDefault(a))
.Select(te => te.Item2).ToList();
if (Policy.BlockAction is IAction)
{
evaluations.Add(EvaluateBlockAction(b, evaluations));
}
foreach (var evaluation in evaluations)
{
evaluation.Action.Render(
evaluation.InputContext,
evaluation.OutputStates
);
}
}
}
}
internal void Append(
Block <T> block,
DateTimeOffset currentTime,
bool evaluateActions,
bool renderActions
)
{
if (!evaluateActions && renderActions)
{
throw new ArgumentException(
$"{nameof(renderActions)} option requires {nameof(evaluateActions)} " +
"to be turned on.",
nameof(renderActions)
);
}
_rwlock.EnterUpgradeableReadLock();
try
{
InvalidBlockException e =
Policy.ValidateNextBlock(this, block);
if (!(e is null))
{
throw e;
}
HashDigest <SHA256>?tip = Store.IndexBlockHash(Id, -1);
var nonceDeltas = new Dictionary <Address, long>();
// block.Transactions have already been sorted by
// the tx nounce order when the block was created
foreach (Transaction <T> tx1 in block.Transactions)
{
Address txSigner = tx1.Signer;
nonceDeltas.TryGetValue(txSigner, out var nonceDelta);
long expectedNonce = nonceDelta + Store.GetTxNonce(Id, txSigner);
if (!expectedNonce.Equals(tx1.Nonce))
{
throw new InvalidTxNonceException(
tx1.Id,
expectedNonce,
tx1.Nonce,
"Transaction nonce is invalid."
);
}
nonceDeltas[txSigner] = nonceDelta + 1;
}
_rwlock.EnterWriteLock();
try
{
Block <T> prevTip = Tip;
Blocks[block.Hash] = block;
foreach (KeyValuePair <Address, long> pair in nonceDeltas)
{
Store.IncreaseTxNonce(Id, pair.Key, pair.Value);
}
Store.AppendIndex(Id, block.Hash);
var tipChangedEventArgs = new TipChangedEventArgs
{
PreviousIndex = prevTip?.Index,
PreviousHash = prevTip?.Hash,
Index = block.Index,
Hash = block.Hash,
};
TipChanged?.Invoke(this, tipChangedEventArgs);
ISet <TxId> txIds = block.Transactions
.Select(t => t.Id)
.ToImmutableHashSet();
Store.UnstageTransactionIds(txIds);
}
finally
{
_rwlock.ExitWriteLock();
}
}
finally
{
_rwlock.ExitUpgradeableReadLock();
}
if (evaluateActions)
{
ExecuteActions(block, renderActions);
}
}
internal System.Action Swap(
BlockChain <T> other,
bool render,
StateCompleterSet <T>?stateCompleters = null)
{
if (other is null)
{
throw new ArgumentNullException(nameof(other));
}
// As render/unrender processing requires every step's states from the branchpoint
// to the new/stale tip, incomplete states need to be complemented anyway...
StateCompleterSet <T> completers = stateCompleters ?? StateCompleterSet <T> .Recalculate;
if (Tip.Equals(other.Tip))
{
// If it's swapped for a chain with the same tip, it means there is no state change.
// Hence render is unnecessary.
render = false;
}
else
{
_logger.Debug(
"The blockchain was reorged from " +
"{OldChainId} (#{OldTipIndex} {OldTipHash}) " +
"to {NewChainId} (#{NewTipIndex} {NewTipHash}).",
Id,
Tip.Index,
Tip.Hash,
other.Id,
other.Tip.Index,
other.Tip.Hash);
}
System.Action renderSwap = () => { };
_rwlock.EnterUpgradeableReadLock();
try
{
// Finds the branch point.
Block <T> branchpoint = FindTopCommon(this, other);
if (branchpoint is null)
{
const string msg =
"A chain cannot be reorged into a heterogeneous chain with a " +
"different genesis.";
throw new InvalidGenesisBlockException(Genesis.Hash, other.Genesis.Hash, msg);
}
_logger.Debug(
"The branchpoint is #{BranchpointIndex} {BranchpointHash}.",
branchpoint.Index,
branchpoint
);
Block <T> oldTip = Tip, newTip = other.Tip;
ImmutableList <Block <T> > rewindPath =
GetRewindPath(this, branchpoint.Hash);
ImmutableList <Block <T> > fastForwardPath =
GetFastForwardPath(other, branchpoint.Hash);
// If there is no rewind, it is not considered as a reorg.
bool reorg = rewindPath.Count > 0;
_rwlock.EnterWriteLock();
try
{
IEnumerable <long> LongRange(long start, long count)
{
for (long i = 0; i < count; i++)
{
yield return(start + i);
}
}
ImmutableHashSet <Transaction <T> >
GetTxsWithRange(BlockChain <T> chain, Block <T> start, Block <T> end) =>
LongRange(start.Index + 1, end.Index - start.Index)
.SelectMany(index => chain[index].Transactions)
.ToImmutableHashSet();
// It assumes reorg is small size. If it was big, this may be heavy task.
ImmutableHashSet <Transaction <T> > txsToStage =
GetTxsWithRange(this, branchpoint, Tip);
ImmutableHashSet <Transaction <T> > txsToUnstage =
GetTxsWithRange(other, branchpoint, other.Tip);
foreach (Transaction <T> tx in txsToStage)
{
StagePolicy.Stage(this, tx);
}
Guid obsoleteId = Id;
Id = other.Id;
Store.SetCanonicalChainId(Id);
_blocks = new BlockSet <T>(Policy.GetHashAlgorithm, Store);
foreach (Transaction <T> tx in txsToUnstage)
{
StagePolicy.Unstage(this, tx.Id);
}
TipChanged?.Invoke(this, (oldTip, newTip));
Store.DeleteChainId(obsoleteId);
}
finally
{
_rwlock.ExitWriteLock();
}
renderSwap = () => RenderSwap(
render: render,
oldTip: oldTip,
newTip: newTip,
branchpoint: branchpoint,
rewindPath: rewindPath,
fastForwardPath: fastForwardPath,
stateCompleters: completers);
}
finally
{
_rwlock.ExitUpgradeableReadLock();
}
return(renderSwap);
}
// FIXME it's very dangerous because replacing Id means
// ALL blocks (referenced by MineBlock(), etc.) will be changed.
// we need to add a synchronization mechanism to handle this correctly.
internal void Swap(BlockChain <T> other, bool render)
{
if (other?.Tip is null)
{
throw new ArgumentException(
$"The chain to be swapped is invalid. Id: {other?.Id}, Tip: {other?.Tip}",
nameof(other));
}
_logger.Debug(
"Swapping block chain. (from: {fromChainId}) (to: {toChainId})", Id, other.Id);
// Finds the branch point.
Block <T> topmostCommon = null;
if (render && !(Tip is null))
{
long shorterHeight =
Math.Min(Count, other.Count) - 1;
for (
Block <T> t = this[shorterHeight], o = other[shorterHeight];
t.PreviousHash is HashDigest <SHA256> tp &&
o.PreviousHash is HashDigest <SHA256> op;
t = this[tp], o = other[op]
)
{
if (t.Equals(o))
{
topmostCommon = t;
break;
}
}
}
_logger.Debug(
"Branchpoint is {branchPoint} (at {index})", topmostCommon, topmostCommon?.Index);
if (render)
{
_logger.Debug("Unrendering abandoned actions...");
// Unrender stale actions.
for (
Block <T> b = Tip;
!(b is null) && b.Index > (topmostCommon?.Index ?? -1) &&
b.PreviousHash is HashDigest <SHA256> ph;
b = this[ph]
)
{
List <ActionEvaluation> evaluations = EvaluateActions(b).ToList();
evaluations.Reverse();
foreach (var evaluation in evaluations)
{
_logger.Debug("Unrender action {action}", evaluation.Action);
evaluation.Action.Unrender(
evaluation.InputContext,
evaluation.OutputStates
);
}
}
_logger.Debug($"Unrender for {nameof(Swap)}() is completed.");
}
try
{
_rwlock.EnterWriteLock();
var tipChangedEventArgs = new TipChangedEventArgs
{
PreviousHash = Tip?.Hash,
PreviousIndex = Tip?.Index,
Hash = other.Tip.Hash,
Index = other.Tip.Index,
};
Guid obsoleteId = Id;
Id = other.Id;
Store.SetCanonicalChainId(Id);
_blocks = new BlockSet <T>(Store);
TipChanged?.Invoke(this, tipChangedEventArgs);
_transactions = new TransactionSet <T>(Store);
Store.DeleteChainId(obsoleteId);
}
finally
{
_rwlock.ExitWriteLock();
}
if (render)
{
_logger.Debug("Rendering actions in new chain");
// Render actions that had been behind.
long startToRenderIndex = topmostCommon is Block <T> branchPoint
? branchPoint.Index + 1
: 0;
RenderBlocks(startToRenderIndex);
_logger.Debug($"Render for {nameof(Swap)}() is completed.");
}
}
// FIXME it's very dangerous because replacing Id means
// ALL blocks (referenced by MineBlock(), etc.) will be changed.
internal System.Action Swap(
BlockChain <T> other,
bool render,
StateCompleterSet <T>?stateCompleters = null)
{
if (other is null)
{
throw new ArgumentNullException(nameof(other));
}
// As render/unrender processing requires every step's states from the branchpoint
// to the new/stale tip, incomplete states need to be complemented anyway...
StateCompleterSet <T> completers = stateCompleters ?? StateCompleterSet <T> .Recalculate;
if (Tip.Equals(other.Tip))
{
// If it's swapped for a chain with the same tip, it means there is no state change.
// Hence render is unnecessary.
render = false;
}
else
{
_logger.Debug(
"The blockchain was reorged from " +
"{OldChainId} (#{OldTipIndex} {OldTipHash}) " +
"to {NewChainId} (#{NewTipIndex} {NewTipHash}).",
Id,
Tip.Index,
Tip.Hash,
other.Id,
other.Tip.Index,
other.Tip.Hash);
}
System.Action renderSwap = () => { };
_rwlock.EnterUpgradeableReadLock();
try
{
// Finds the branch point.
Block <T> branchpoint = FindTopCommon(this, other);
if (branchpoint is null)
{
const string msg =
"A chain cannot be reorged into a heterogeneous chain with a " +
"different genesis.";
throw new InvalidGenesisBlockException(Genesis.Hash, other.Genesis.Hash, msg);
}
_logger.Debug(
"The branchpoint is #{BranchpointIndex} {BranchpointHash}.",
branchpoint.Index,
branchpoint
);
Block <T> oldTip = Tip, newTip = other.Tip;
ImmutableList <Block <T> > rewindPath =
GetRewindPath(this, branchpoint.Hash);
ImmutableList <Block <T> > fastForwardPath =
GetFastForwardPath(other, branchpoint.Hash);
// If there is no rewind, it is not considered as a reorg.
bool reorg = rewindPath.Count > 0;
_rwlock.EnterWriteLock();
try
{
IEnumerable <Transaction <T> >
GetTxsWithRange(BlockChain <T> chain, Block <T> start, Block <T> end)
=> Enumerable
.Range((int)start.Index + 1, (int)(end.Index - start.Index))
.SelectMany(x =>
{
// FIXME: Change the type of IBlockContent<T>.Transactions to
// IImmutableSet<Transaction<T>>, and define a distinct property
// to Block<T> for this ordering.
Block <T> block = chain[x];
return(ActionEvaluator <T> .OrderTxsForEvaluation(
block.ProtocolVersion,
block.Transactions,
block.PreEvaluationHash
));
});
// It assumes reorg is small size. If it was big, this may be heavy task.
ImmutableHashSet <Transaction <T> > unstagedTxs =
GetTxsWithRange(this, branchpoint, Tip).ToImmutableHashSet();
ImmutableHashSet <Transaction <T> > stageTxs =
GetTxsWithRange(other, branchpoint, other.Tip).ToImmutableHashSet();
ImmutableHashSet <Transaction <T> > restageTxs = unstagedTxs.Except(stageTxs);
foreach (Transaction <T> restageTx in restageTxs)
{
StagePolicy.Stage(this, restageTx);
}
Guid obsoleteId = Id;
Id = other.Id;
Store.SetCanonicalChainId(Id);
_blocks = new BlockSet <T>(Policy.GetHashAlgorithm, Store);
TipChanged?.Invoke(this, (oldTip, newTip));
Store.DeleteChainId(obsoleteId);
}
finally
{
_rwlock.ExitWriteLock();
}
renderSwap = () => RenderSwap(
render: render,
oldTip: oldTip,
newTip: newTip,
branchpoint: branchpoint,
rewindPath: rewindPath,
fastForwardPath: fastForwardPath,
stateCompleters: completers);
}
finally
{
_rwlock.ExitUpgradeableReadLock();
}
return(renderSwap);
}
