private async Task SyncPreviousBlocksAsync(
BlockChain <T> blockChain,
BoundPeer peer,
BlockHash?stop,
IProgress <BlockDownloadState> progress,
TimeSpan timeout,
long totalBlockCount,
int logSessionId,
CancellationToken cancellationToken
)
{
long previousTipIndex = blockChain.Tip?.Index ?? -1;
BlockChain <T> synced = null;
try
{
long currentTipIndex = blockChain.Tip?.Index ?? -1;
long receivedBlockCount = currentTipIndex - previousTipIndex;
const string startMsg = "{SessionId}: Starts " + nameof(FillBlocksAsync) + "()...";
_logger.Debug(startMsg, logSessionId);
FillBlocksAsyncStarted.Set();
synced = await FillBlocksAsync(
peer,
blockChain,
stop,
progress,
totalBlockCount,
receivedBlockCount,
true,
timeout,
logSessionId,
cancellationToken
);
const string finishMsg = "{SessionId}: Finished " + nameof(FillBlocksAsync) + "().";
_logger.Debug(finishMsg, logSessionId);
}
catch (Exception)
{
FillBlocksAsyncFailed.Set();
throw;
}
finally
{
var canonComparer = BlockChain.Policy.CanonicalChainComparer;
if (synced is { } syncedB &&
!syncedB.Id.Equals(blockChain?.Id) &&
(!(blockChain.Tip is { } tip&& syncedB.Tip is { } syncedTip) ||
canonComparer.Compare(
blockChain.PerceiveBlock(tip),
blockChain.PerceiveBlock(
syncedTip,
syncedB.PerceiveBlock(syncedTip).PerceivedTime
)
) < 0
)
)
{
_logger.Debug(
"{SessionId}: Swap the chain {ChainIdA} for the chain {ChainIdB}...",
logSessionId,
blockChain.Id,
synced.Id
);
blockChain.Swap(
synced,
render: true,
stateCompleters: null
);
_logger.Debug(
"{SessionId}: The chain {ChainIdB} replaced {ChainIdA}",
logSessionId,
synced.Id,
blockChain.Id
);
}
}
}
private bool BlockCandidateProcess(
SortedList <long, Block <T> > candidate,
TimeSpan timeout,
CancellationToken cancellationToken)
{
BlockChain <T> synced = null;
System.Action renderSwap = () => { };
const string methodName =
nameof(Swarm <T>) + "<T>." + nameof(BlockCandidateProcess) + "()";
try
{
FillBlocksAsyncStarted.Set();
_logger.Debug(
methodName + " starts to append. Current tip: #{BlockIndex}.",
BlockChain.Tip.Index
);
synced = AppendPreviousBlocks(
blockChain: BlockChain,
candidate: candidate,
timeout: timeout,
evaluateActions: true);
ProcessFillBlocksFinished.Set();
_logger.Debug(
methodName + " finished appending blocks. Synced tip: #{BlockIndex}.",
synced.Tip.Index
);
}
catch (Exception e)
{
_logger.Error(e, methodName + " failed to append blocks.");
FillBlocksAsyncFailed.Set();
return(false);
}
var canonComparer = BlockChain.Policy.CanonicalChainComparer;
if (synced is { } syncedB &&
!syncedB.Id.Equals(BlockChain?.Id) &&
(canonComparer.Compare(
BlockChain.PerceiveBlock(BlockChain.Tip),
BlockChain.PerceiveBlock(syncedB.Tip)) < 0
)
)
{
_logger.Debug(
"Swapping chain {ChainIdA} with chain {ChainIdB}...",
BlockChain.Id,
synced.Id
);
renderSwap = BlockChain.Swap(
synced,
render: true,
stateCompleters: null);
_logger.Debug(
"Swapped chain {ChainIdA} with chain {ChainIdB}.",
BlockChain.Id,
synced.Id
);
}
renderSwap();
BroadcastBlock(BlockChain.Tip);
return(true);
}