private async Task DownloadNextBlocks(Node node, CancellationToken ctsToken, int maxBlocksToDownload = 1)
{
var heights = new List <Height>();
try
{
await _sem.WaitAsync(ctsToken).ConfigureAwait(false);
if (BlocksToDownload.Count == 0)
{
await Task.Delay(100, ctsToken).ContinueWith(tsk => { }).ConfigureAwait(false);
return;
}
if (BlocksToDownload.Count < maxBlocksToDownload * 2)
{
maxBlocksToDownload = 1;
}
for (int i = 0; i < maxBlocksToDownload; i++)
{
// todo check if we have that much block
var height = BlocksToDownload.Min();
BlocksToDownload.TryRemove(height);
heights.Add(height);
}
}
finally
{
_sem.Release();
}
try
{
var headers = new HashSet <ChainedBlock>();
foreach (var height in heights)
{
WalletJob.TryGetHeader(height, out ChainedBlock neededHeader);
headers.Add(neededHeader);
}
var delayMinutes = heights.Count;
var timeoutToken = new CancellationTokenSource(TimeSpan.FromMinutes(delayMinutes)).Token;
var downloadCtsToken = CancellationTokenSource.CreateLinkedTokenSource(timeoutToken, ctsToken).Token;
HashSet <Block> blocks = null;
try
{
blocks = new HashSet <Block>(await Task.Run(() => node.GetBlocks(headers.ToArray(), downloadCtsToken)).ConfigureAwait(false));
}
catch
{
if (timeoutToken.IsCancellationRequested)
{
node.DisconnectAsync($"Block download time > {delayMinutes}min");
}
else
{
node.DisconnectAsync("Block download failed");
}
blocks = null;
}
if (blocks == null)
{
foreach (var height in heights)
{
BlocksToDownload.Add(height);
}
}
else
{
int i = 0;
foreach (var block in blocks)
{
DownloadedBlocks.AddOrReplace(heights[i], block);
i++;
}
}
}
catch
{
try
{
await _sem.WaitAsync(ctsToken).ConfigureAwait(false);
foreach (var height in heights)
{
BlocksToDownload.Add(height);
}
}
finally
{
_sem.Release();
}
}
}