async Task RetrieveBlocks(IBlocksRetrieverHandler handler)
{
var cancellationToken = this.retrieveBlocksCancelSource.Token;
var height = await handler.GetBlockHintAsync(cancellationToken);
while (true)
{
// Get block.
Block block;
using (var rpc = await this.rpc.CreateChainInformationRpcAsync(cancellationToken))
{
try
{
block = await rpc.GetBlockAsync(height, cancellationToken);
}
catch (RPCException ex) when(ex.RPCCode == RPCErrorCode.RPC_INVALID_PARAMETER)
{
// Invalid block height.
await WaitNewBlockAsync(cancellationToken);
continue;
}
}
// Execute handler.
height = await handler.ProcessBlockAsync(block, height, cancellationToken);
}
}
async Task RetrieveBlocks(IBlocksRetrieverHandler handler)
{
var cancellationToken = this.retrieveBlocksCancelSource.Token;
var height = await handler.GetStartBlockAsync(cancellationToken);
while (true)
{
// Get block.
Block block;
using (var rpc = await this.rpc.CreateChainInformationRpcAsync(cancellationToken))
{
try
{
block = await rpc.GetBlockAsync(height, cancellationToken);
}
catch (RPCException ex) when(ex.RPCCode == RPCErrorCode.RPC_INVALID_PARAMETER) // Invalid height.
{
var info = await rpc.GetChainInfoAsync(cancellationToken);
var blocks = (int)info.Blocks;
if (blocks >= height)
{
// There is a new block already.
continue;
}
if (blocks == height - 1)
{
// A block of the target height is not available right now.
await WaitNewBlockAsync(cancellationToken);
continue;
}
// There is a re-org happened.
await handler.DiscardBlocksAsync(blocks, cancellationToken);
height = blocks;
continue;
}
}
// Execute handler.
height = await handler.ProcessBlockAsync(block, height, cancellationToken);
}
}
public BlocksRetrieverTests()
{
// Start ZeroMQ publisher.
this.publisher = new PublisherSocket();
try
{
var publisherPort = this.publisher.BindRandomPort("tcp://localhost");
// Mock config.
var builder = new ConfigurationBuilder();
builder.AddInMemoryCollection(new Dictionary <string, string>()
{
{ "Zcoin:Rpc:Address", "http://127.0.0.1:8888" },
{ "Zcoin:Rpc:UserName", "root" },
{ "Zcoin:Rpc:Password", "abc" },
{ "Zcoin:ZeroMq:Address", "tcp://localhost:" + publisherPort }
});
this.config = builder.Build();
// Mock RPC.
this.rpc = new Mock <IChainInformationRpc>();
this.rpcFactory = new Mock <IRpcFactory>();
this.rpcFactory.Setup(f => f.CreateChainInformationRpcAsync(It.IsAny <CancellationToken>()))
.ReturnsAsync(this.rpc.Object);
// Mock handler.
this.handler = Substitute.For <IBlocksRetrieverHandler>();
// Create test subject.
this.subject = new BlocksRetriever(this.config, this.rpcFactory.Object);
}
catch
{
this.publisher.Dispose();
throw;
}
}
public Task <Task> StartAsync(IBlocksRetrieverHandler handler, CancellationToken cancellationToken)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
ThrowIfAlreadyDisposed();
ThrowIfAlreadyRunning();
Debug.Assert(this.subscriber == null);
Debug.Assert(this.poller == null);
Debug.Assert(this.newBlockNotification == null);
Debug.Assert(this.retrieveBlocksCancelSource == null);
Debug.Assert(this.retrieveBlocksTask == null);
// Subscribe to ZeroMQ.
this.subscriber = new SubscriberSocket();
try
{
this.poller = new NetMQPoller();
try
{
this.subscriber.ReceiveReady += (sender, e) => NotifyNewBlock();
this.subscriber.Connect(this.config.ZeroMq.Address);
this.subscriber.Subscribe("hashblock");
this.poller.Add(this.subscriber);
this.poller.RunAsync();
// Start background tasks to retrieve blocks.
this.retrieveBlocksCancelSource = new CancellationTokenSource();
try
{
this.retrieveBlocksTask = Task.Run(() => RetrieveBlocks(handler));
}
catch
{
this.retrieveBlocksCancelSource.Dispose();
this.retrieveBlocksCancelSource = null;
throw;
}
}
catch
{
this.poller.Dispose();
this.poller = null;
throw;
}
}
catch
{
this.subscriber.Dispose();
this.subscriber = null;
throw;
}
return(Task.FromResult(this.retrieveBlocksTask));
}
