/// <summary>
/// Download and attach blocks
/// UseSuggestedPeer == true: Download blocks from suggested peer directly;
/// Target download height > peer lib height, download blocks from suggested peer;
/// Target download height <= peer lib height, select a random peer to download.
/// </summary>
/// <param name="downloadBlockDto"></param>
/// <returns></returns>
public async Task <DownloadBlocksResult> DownloadBlocksAsync(DownloadBlockDto downloadBlockDto)
{
var downloadResult = new DownloadBlocksResult();
var peerPubkey = downloadBlockDto.SuggestedPeerPubkey;
try
{
if (UseSuggestedPeer(downloadBlockDto))
{
downloadResult = await DownloadBlocksAsync(peerPubkey, downloadBlockDto);
}
else
{
// If cannot get the blocks, there should be network problems or bad peer,
// because we have selected peer with lib height greater than or equal to the target height.
// 1. network problems, need to retry from other peer.
// 2. not network problems, this peer or the last peer is bad peer, we need to remove it.
var downloadTargetHeight =
downloadBlockDto.PreviousBlockHeight + downloadBlockDto.MaxBlockDownloadCount;
var exceptedPeers = new List <string> {
_blockSyncStateProvider.LastRequestPeerPubkey
};
var retryTimes = 2;
while (true)
{
peerPubkey = GetRandomPeerPubkey(downloadBlockDto.SuggestedPeerPubkey, downloadTargetHeight,
exceptedPeers);
downloadResult = await DownloadBlocksAsync(peerPubkey, downloadBlockDto);
if (downloadResult.Success || retryTimes <= 0)
{
break;
}
exceptedPeers.Add(peerPubkey);
retryTimes--;
}
if (downloadResult.Success && downloadResult.DownloadBlockCount == 0)
{
await CheckBadPeerAsync(peerPubkey, downloadBlockDto.PreviousBlockHash,
downloadBlockDto.PreviousBlockHeight);
}
}
}
catch (BlockDownloadException e)
{
await LocalEventBus.PublishAsync(new BadPeerFoundEventData
{
BlockHash = e.BlockHash,
BlockHeight = e.BlockHeight,
PeerPubkey = e.PeerPubkey
});
}
return(downloadResult);
}
private bool UseSuggestedPeer(DownloadBlockDto downloadBlockDto)
{
if (downloadBlockDto.UseSuggestedPeer)
{
return(true);
}
var suggestedPeer = _networkService.GetPeerByPubkey(downloadBlockDto.SuggestedPeerPubkey);
var downloadTargetHeight = downloadBlockDto.PreviousBlockHeight + downloadBlockDto.MaxBlockDownloadCount;
if (downloadTargetHeight > suggestedPeer.LastKnownLibHeight)
{
return(true);
}
return(false);
}
/// <summary>
/// Download and attach blocks
/// UseSuggestedPeer == true: Download blocks from suggested peer directly;
/// Target download height > peer lib height, download blocks from suggested peer;
/// Target download height <= peer lib height, select a random peer to download.
/// </summary>
/// <param name="downloadBlockDto"></param>
/// <returns></returns>
public async Task <DownloadBlocksResult> DownloadBlocksAsync(DownloadBlockDto downloadBlockDto)
{
DownloadBlocksResult downloadResult;
var peerPubkey = downloadBlockDto.SuggestedPeerPubkey;
if (UseSuggestedPeer(downloadBlockDto))
{
downloadResult = await DownloadBlocksAsync(downloadBlockDto.PreviousBlockHash,
peerPubkey, downloadBlockDto.BatchRequestBlockCount,
downloadBlockDto.MaxBlockDownloadCount);
}
else
{
// If cannot get the blocks, there should be network problems or bad peer,
// because we have selected peer with lib height greater than or equal to the target height.
// 1. network problems, need to retry from other peer.
// 2. not network problems, this peer or the last peer is bad peer, we need to remove it.
var downloadTargetHeight =
downloadBlockDto.PreviousBlockHeight + downloadBlockDto.MaxBlockDownloadCount;
var exceptedPeers = new List <string> {
_blockSyncStateProvider.LastRequestPeerPubkey
};
var retryTimes = 1;
while (true)
{
peerPubkey = GetRandomPeerPubkey(downloadBlockDto.SuggestedPeerPubkey, downloadTargetHeight,
exceptedPeers);
downloadResult = await DownloadBlocksAsync(downloadBlockDto.PreviousBlockHash, peerPubkey,
downloadBlockDto.BatchRequestBlockCount, downloadBlockDto.MaxBlockDownloadCount);
if (downloadResult.Success || retryTimes <= 0)
{
break;
}
exceptedPeers.Add(peerPubkey);
retryTimes--;
}
if (downloadResult.Success && downloadResult.DownloadBlockCount == 0)
{
var checkResult = await CheckIrreversibleBlockHashAsync(downloadBlockDto.PreviousBlockHash,
downloadBlockDto.PreviousBlockHeight);
if (checkResult.HasValue)
{
Logger.LogWarning(
$"Found bad peer: peerPubkey: {peerPubkey}, block hash: {downloadBlockDto.PreviousBlockHash}, block height: {downloadBlockDto.PreviousBlockHeight}");
await LocalEventBus.PublishAsync(new IncorrectIrreversibleBlockEventData
{
BlockHash = downloadBlockDto.PreviousBlockHash,
BlockHeight = downloadBlockDto.PreviousBlockHeight,
BlockSenderPubkey = checkResult.Value
? peerPubkey
: _blockSyncStateProvider.LastRequestPeerPubkey
});
}
}
}
return(downloadResult);
}
private async Task <DownloadBlocksResult> DownloadBlocksAsync(string peerPubkey,
DownloadBlockDto downloadBlockDto)
{
var downloadBlockCount = 0;
var lastDownloadBlockHash = downloadBlockDto.PreviousBlockHash;
var lastDownloadBlockHeight = downloadBlockDto.PreviousBlockHeight;
Logger.LogDebug(
$"Download blocks start with block height: {lastDownloadBlockHeight}, hash: {lastDownloadBlockHash}, PeerPubkey: {peerPubkey}");
while (downloadBlockCount < downloadBlockDto.MaxBlockDownloadCount)
{
var getBlocksResult = await _networkService.GetBlocksAsync(lastDownloadBlockHash,
downloadBlockDto.BatchRequestBlockCount, peerPubkey);
if (!getBlocksResult.Success)
{
return(new DownloadBlocksResult
{
Success = false
});
}
var blocksWithTransactions = getBlocksResult.Payload;
if (blocksWithTransactions == null || !blocksWithTransactions.Any())
{
Logger.LogDebug(
$"No blocks returned from peer: {peerPubkey}, Previous block height: {lastDownloadBlockHeight}, hash: {lastDownloadBlockHash}.");
break;
}
foreach (var blockWithTransactions in blocksWithTransactions)
{
Logger.LogDebug($"Processing block {blockWithTransactions}.");
if (blockWithTransactions.Height != lastDownloadBlockHeight + 1 ||
blockWithTransactions.Header.PreviousBlockHash != lastDownloadBlockHash)
{
Logger.LogWarning(
$"Received invalid block, peer: {peerPubkey}, block hash: {blockWithTransactions.GetHash()}, block height: {blockWithTransactions.Height}");
throw new BlockDownloadException(blockWithTransactions.GetHash(), blockWithTransactions.Height,
peerPubkey);
}
lastDownloadBlockHash = blockWithTransactions.GetHash();
lastDownloadBlockHeight = blockWithTransactions.Height;
EnqueueAttachBlockJob(blockWithTransactions, peerPubkey);
downloadBlockCount++;
}
var lastBlock = blocksWithTransactions.Last();
lastDownloadBlockHash = lastBlock.GetHash();
lastDownloadBlockHeight = lastBlock.Height;
}
if (downloadBlockCount != 0)
{
_blockSyncStateProvider.SetDownloadJobTargetState(lastDownloadBlockHash, false);
_blockSyncStateProvider.LastRequestPeerPubkey = peerPubkey;
}
return(new DownloadBlocksResult
{
Success = true,
DownloadBlockCount = downloadBlockCount,
LastDownloadBlockHash = lastDownloadBlockHash,
LastDownloadBlockHeight = lastDownloadBlockHeight
});
}
public async Task <DownloadBlocksResult> DownloadBlocksAsync(DownloadBlockDto downloadBlockDto)
{
var downloadBlockCount = 0;
var lastDownloadBlockHash = downloadBlockDto.PreviousBlockHash;
var lastDownloadBlockHeight = downloadBlockDto.PreviousBlockHeight;
while (downloadBlockCount < downloadBlockDto.MaxBlockDownloadCount)
{
Logger.LogDebug(
$"Request blocks start with block hash: {lastDownloadBlockHash}, block height: {lastDownloadBlockHeight}");
var blocksWithTransactions = await _networkService.GetBlocksAsync(lastDownloadBlockHash,
downloadBlockDto.BatchRequestBlockCount, downloadBlockDto.SuggestedPeerPubkey);
if (blocksWithTransactions == null || !blocksWithTransactions.Any())
{
Logger.LogWarning("No blocks returned.");
break;
}
if (blocksWithTransactions.First().Header.PreviousBlockHash != lastDownloadBlockHash)
{
throw new InvalidOperationException(
$"Previous block not match previous {lastDownloadBlockHash}, network back {blocksWithTransactions.First().Header.PreviousBlockHash}");
}
foreach (var blockWithTransactions in blocksWithTransactions)
{
Logger.LogDebug($"Processing block {blockWithTransactions}.");
_blockSyncQueueService.Enqueue(
async() =>
{
await _blockSyncAttachService.AttachBlockWithTransactionsAsync(blockWithTransactions,
async() =>
{
_blockSyncStateProvider.TryUpdateDownloadJobTargetState(blockWithTransactions.GetHash(), true);
});
},
OSConstants.BlockSyncAttachQueueName);
downloadBlockCount++;
}
var lastBlock = blocksWithTransactions.Last();
lastDownloadBlockHash = lastBlock.GetHash();
lastDownloadBlockHeight = lastBlock.Height;
}
if (lastDownloadBlockHash != null)
{
_blockSyncStateProvider.SetDownloadJobTargetState(lastDownloadBlockHash, false);
}
return(new DownloadBlocksResult
{
DownloadBlockCount = downloadBlockCount,
LastDownloadBlockHash = lastDownloadBlockHash,
LastDownloadBlockHeight = lastDownloadBlockHeight
});
}