/// <summary>
/// Tries to perform mempool cleanup with the help of the connected nodes.
/// NOTE: This results in heavy network activity! https://github.com/zkSNACKs/WalletWasabi/issues/1273
/// </summary>
public async Task <bool> TryPerformMempoolCleanupAsync(NodesGroup nodes, CancellationToken cancel)
{
// If already cleaning, then no need to run it that often.
if (Interlocked.CompareExchange(ref _cleanupInProcess, 1, 0) == 1)
{
return(false);
}
// This function is designed to prevent forever growing mempool.
try
{
if (!TransactionHashes.Any())
{
return(true); // There's nothing to cleanup.
}
var delay = TimeSpan.FromMinutes(1);
if (nodes?.ConnectedNodes is null)
{
return(false);
}
while (nodes.ConnectedNodes.Count != nodes.MaximumNodeConnection && nodes.ConnectedNodes.All(x => x.IsConnected))
{
if (cancel.IsCancellationRequested)
{
return(false);
}
Logger.LogInfo <MemPoolService>($"Not all nodes were in a connected state. Delaying mempool cleanup for {delay.TotalSeconds} seconds...");
await Task.Delay(delay, cancel);
}
Logger.LogInfo <MemPoolService>("Start cleaning out mempool...");
var allTxs = new HashSet <uint256>();
foreach (Node node in nodes.ConnectedNodes)
{
try
{
if (!node.IsConnected)
{
continue;
}
if (cancel.IsCancellationRequested)
{
return(false);
}
uint256[] txs = node.GetMempool(cancel);
if (cancel.IsCancellationRequested)
{
return(false);
}
allTxs.UnionWith(txs);
if (cancel.IsCancellationRequested)
{
return(false);
}
}
catch (Exception ex) when((ex is InvalidOperationException && ex.Message.StartsWith("The node is not in a connected state", StringComparison.InvariantCultureIgnoreCase)) ||
ex is OperationCanceledException ||
ex is TaskCanceledException ||
ex is TimeoutException)
{
Logger.LogTrace <MemPoolService>(ex);
}
catch (Exception ex)
{
Logger.LogDebug <MemPoolService>(ex);
}
}
int removedTxCount = 0;
foreach (uint256 tx in TransactionHashes.ToArray())
{
if (!allTxs.Contains(tx))
{
if (TransactionHashes.TryRemove(tx))
{
removedTxCount++;
}
}
}
Logger.LogInfo <MemPoolService>($"{removedTxCount} transactions were cleaned from mempool.");
return(true);
}
catch (Exception ex) when(ex is OperationCanceledException ||
ex is TaskCanceledException ||
ex is TimeoutException)
{
Logger.LogTrace <MemPoolService>(ex);
}
catch (Exception ex)
{
Logger.LogDebug <MemPoolService>(ex);
}
finally
{
Interlocked.Exchange(ref _cleanupInProcess, 0);
}
return(false);
}
