/// <summary>
/// Adds download task to the peer's list of pending download tasks.
/// </summary>
/// <param name="peer">Peer to add task to.</param>
/// <param name="blockHash">Hash of the block being assigned to <paramref name="peer"/> for download.</param>
/// <remarks>The caller of this method is responsible for holding <see cref="lockObject"/>.</remarks>
private void AddPeerPendingDownloadLocked(BlockPullerBehavior peer, uint256 blockHash)
{
this.logger.LogTrace("({0}:'{1:x}',{2}:'{3}')", nameof(peer), peer.GetHashCode(), nameof(blockHash), blockHash);
Dictionary <uint256, DownloadAssignment> peerPendingDownloads;
if (!this.peersPendingDownloads.TryGetValue(peer, out peerPendingDownloads))
{
peerPendingDownloads = new Dictionary <uint256, DownloadAssignment>();
this.peersPendingDownloads.Add(peer, peerPendingDownloads);
}
DownloadAssignment downloadTask = new DownloadAssignment(blockHash);
peerPendingDownloads.Add(blockHash, downloadTask);
this.logger.LogTrace("(-)");
}
/// <summary>
/// When a peer downloads a block, it notifies the puller about the block by calling this method.
/// <para>
/// The downloaded task is removed from the list of pending downloads
/// and it is also removed from the <see cref="assignedBlockTasks"/> - i.e. the task is no longer assigned to the peer.
/// And finally, it is added to the list of downloaded blocks, provided that the block is not present there already.
/// </para>
/// </summary>
/// <param name="peer">Peer that finished the download task.</param>
/// <param name="blockHash">Hash of the downloaded block.</param>
/// <param name="downloadedBlock">Description of the downloaded block.</param>
/// <returns>
/// <c>true</c> if the download task for the block was assigned to <paramref name="peer"/>
/// and the task was removed and added to the list of downloaded blocks.
/// <c>false</c> if the downloaded block has been assigned to another peer
/// or if the block was already on the list of downloaded blocks.
/// </returns>
internal bool DownloadTaskFinished(BlockPullerBehavior peer, uint256 blockHash, DownloadedBlock downloadedBlock)
{
this.logger.LogTrace("({0}:'{1:x}',{2}:'{3}',{4}.{5}:{6})", nameof(peer), peer.GetHashCode(), nameof(blockHash), blockHash, nameof(downloadedBlock), nameof(downloadedBlock.Length), downloadedBlock.Length);
bool error = false;
bool res = false;
double peerQualityAdjustment = 0;
lock (this.lockObject)
{
BlockPullerBehavior peerAssigned;
if (this.assignedBlockTasks.TryGetValue(blockHash, out peerAssigned))
{
Dictionary <uint256, DownloadAssignment> peerPendingDownloads;
if (this.peersPendingDownloads.TryGetValue(peer, out peerPendingDownloads))
{
if (peer == peerAssigned)
{
DownloadAssignment downloadTask = null;
peerPendingDownloads.TryGetValue(blockHash, out downloadTask);
if (this.assignedBlockTasks.Remove(blockHash) && peerPendingDownloads.Remove(blockHash))
{
// Task was assigned to this peer and was removed.
if (this.downloadedBlocks.TryAdd(blockHash, downloadedBlock))
{
long blockDownloadTime = downloadTask.Finish();
this.peerQuality.AddSample(peer, blockDownloadTime, downloadedBlock.Length);
peerQualityAdjustment = this.peerQuality.CalculateQualityAdjustment(blockDownloadTime, downloadedBlock.Length);
this.logger.LogTrace("Block '{0}' size '{1}' downloaded by peer '{2:x}' in {3} ms, peer's score will be adjusted by {4}.", blockHash, downloadedBlock.Length, peer.GetHashCode(), blockDownloadTime, peerQualityAdjustment);
res = true;
}
else
{
this.logger.LogTrace("Block '{0}' already present on the list of downloaded blocks.", blockHash);
}
}
else
{
// Task was assigned to this peer but the data are inconsistent.
error = true;
}
}
else
{
// Before this peer provided the block, it has been assigned to other peer, which is OK.
this.logger.LogTrace("Incoming block '{0}' is assigned to peer '{1:x}', not to '{2:x}'.", blockHash, peerAssigned.GetHashCode(), peer.GetHashCode());
}
}
else
{
// Peer's pending downloads were probably released, which is OK.
this.logger.LogTrace("Peer '{0:x}' has no assignments.", peer.GetHashCode());
}
}
else
{
// The task was probably assigned to other peer and that task completed before this peer provided the block, which is OK.
this.logger.LogTrace("Incoming block '{0}' is not pending.", blockHash);
}
}
if (error)
{
this.logger.LogCritical("Data structures inconsistency, please notify the devs.");
// TODO: This exception is going to be silently discarded by Node_MessageReceived.
throw new InvalidOperationException("Data structures inconsistency, please notify the devs.");
}
if (res)
{
peer.UpdateQualityScore(peerQualityAdjustment);
}
this.logger.LogTrace("(-):{0}", res);
return(res);
}