public async Task <long> DownloadHeaders(PeerInfo bestPeer, int newBlocksToSkip, CancellationToken cancellation)
{
if (bestPeer == null)
{
string message = $"Not expecting best peer to be null inside the {nameof(BlockDownloader)}";
_logger.Error(message);
throw new ArgumentNullException(message);
}
int headersSynced = 0;
int ancestorLookupLevel = 0;
long currentNumber = Math.Max(0, Math.Min(_blockTree.BestKnownNumber, bestPeer.HeadNumber - 1));
while (bestPeer.TotalDifficulty > (_blockTree.BestSuggestedHeader?.TotalDifficulty ?? 0) && currentNumber <= bestPeer.HeadNumber)
{
if (_logger.IsTrace)
{
_logger.Trace($"Continue headers sync with {bestPeer} (our best {_blockTree.BestKnownNumber})");
}
long blocksLeft = bestPeer.HeadNumber - currentNumber - newBlocksToSkip;
int headersToRequest = (int)Math.Min(blocksLeft + 1, _syncBatchSize.Current);
if (headersToRequest <= 1)
{
break;
}
if (_logger.IsTrace)
{
_logger.Trace($"Headers request {currentNumber}+{headersToRequest} to peer {bestPeer} with {bestPeer.HeadNumber} blocks. Got {currentNumber} and asking for {headersToRequest} more.");
}
BlockHeader[] headers = await RequestHeaders(bestPeer, cancellation, currentNumber, headersToRequest);
BlockHeader startingPoint = headers[0] == null ? null : _blockTree.FindHeader(headers[0].Hash, BlockTreeLookupOptions.TotalDifficultyNotNeeded);
if (startingPoint == null)
{
ancestorLookupLevel++;
if (ancestorLookupLevel >= _ancestorJumps.Length)
{
if (_logger.IsWarn)
{
_logger.Warn($"Could not find common ancestor with {bestPeer}");
}
throw new EthSynchronizationException("Peer with inconsistent chain in sync");
}
int ancestorJump = _ancestorJumps[ancestorLookupLevel] - _ancestorJumps[ancestorLookupLevel - 1];
currentNumber = currentNumber >= ancestorJump ? (currentNumber - ancestorJump) : 0L;
continue;
}
ancestorLookupLevel = 0;
_sinceLastTimeout++;
if (_sinceLastTimeout >= 2)
{
// if peers are not timing out then we can try to be slightly more eager
_syncBatchSize.Expand();
}
for (int i = 1; i < headers.Length; i++)
{
if (cancellation.IsCancellationRequested)
{
break;
}
BlockHeader currentHeader = headers[i];
if (currentHeader == null)
{
if (headersSynced > 0)
{
break;
}
return(0);
}
if (_logger.IsTrace)
{
_logger.Trace($"Received {currentHeader} from {bestPeer:s}");
}
bool isValid = i > 1 ? _blockValidator.ValidateHeader(currentHeader, headers[i - 1], false) : _blockValidator.ValidateHeader(currentHeader, false);
if (!isValid)
{
throw new EthSynchronizationException($"{bestPeer} sent a block {currentHeader.ToString(BlockHeader.Format.Short)} with an invalid header");
}
if (HandleAddResult(bestPeer, currentHeader, i == 0, _blockTree.Insert(currentHeader)))
{
headersSynced++;
}
currentNumber = currentNumber + 1;
}
if (headersSynced > 0)
{
_syncReport.FullSyncBlocksDownloaded.Update(_blockTree.BestSuggestedHeader?.Number ?? 0);
_syncReport.FullSyncBlocksKnown = bestPeer.HeadNumber;
}
else
{
break;
}
}
return(headersSynced);
}
public async Task <long> DownloadHeaders(PeerInfo bestPeer, int newBlocksToSkip, CancellationToken cancellation)
{
if (bestPeer == null)
{
string message = $"Not expecting best peer to be null inside the {nameof(BlockDownloader)}";
_logger.Error(message);
throw new ArgumentNullException(message);
}
int headersSynced = 0;
int ancestorLookupLevel = 0;
long currentNumber = Math.Max(0, Math.Min(_blockTree.BestKnownNumber, bestPeer.HeadNumber - 1));
while (bestPeer.TotalDifficulty > (_blockTree.BestSuggested?.TotalDifficulty ?? 0) && currentNumber <= bestPeer.HeadNumber)
{
if (_logger.IsTrace)
{
_logger.Trace($"Continue headers sync with {bestPeer} (our best {_blockTree.BestKnownNumber})");
}
if (ancestorLookupLevel > MaxReorganizationLength)
{
if (_logger.IsWarn)
{
_logger.Warn($"Could not find common ancestor with {bestPeer}");
}
throw new EthSynchronizationException("Peer with inconsistent chain in sync");
}
long blocksLeft = bestPeer.HeadNumber - currentNumber - newBlocksToSkip;
int headersToRequest = (int)BigInteger.Min(blocksLeft + 1, _syncBatchSize.Current);
if (headersToRequest <= 1)
{
break;
}
if (_logger.IsTrace)
{
_logger.Trace($"Headers request {currentNumber}+{headersToRequest} to peer {bestPeer} with {bestPeer.HeadNumber} blocks. Got {currentNumber} and asking for {headersToRequest} more.");
}
var headers = await RequestHeaders(bestPeer, cancellation, currentNumber, headersToRequest);
BlockHeader startingPoint = headers[0] == null ? null : _blockTree.FindHeader(headers[0].Hash);
if (startingPoint == null)
{
ancestorLookupLevel += _syncBatchSize.Current;
currentNumber = currentNumber >= _syncBatchSize.Current ? (currentNumber - _syncBatchSize.Current) : 0L;
continue;
}
_sinceLastTimeout++;
if (_sinceLastTimeout >= 2)
{
_syncBatchSize.Expand();
}
for (int i = 1; i < headers.Length; i++)
{
if (cancellation.IsCancellationRequested)
{
break;
}
BlockHeader currentHeader = headers[i];
if (currentHeader == null)
{
if (headersSynced > 0)
{
break;
}
return(0);
}
if (_logger.IsTrace)
{
_logger.Trace($"Received {currentHeader} from {bestPeer:s}");
}
if (!_blockValidator.ValidateHeader(currentHeader, false))
{
throw new EthSynchronizationException($"{bestPeer} sent a block {currentHeader.ToString(BlockHeader.Format.Short)} with an invalid header");
}
if (HandleAddResult(currentHeader, i == 0, _blockTree.SuggestHeader(currentHeader)))
{
headersSynced++;
}
currentNumber = currentNumber + 1;
}
if (headersSynced > 0)
{
_syncStats.ReportBlocksDownload(_blockTree.BestSuggested?.Number ?? 0, bestPeer.HeadNumber);
}
}
return(headersSynced);
}
