/// <summary>
/// Subscribes to an expression but does not retrieve old events.
/// </summary>
/// <param name="expression">The query to subscribe to</param>
/// <param name="requestId">Request ID specified by client</param>
/// <param name="callback">Callback function used to post transactions with</param>
/// <returns>Subscription ID. used to unsubscribe and identify subscription when transactions are returned.</returns>
public Guid Subscribe(string expression, Guid requestId, Action <Guid, Transaction> callback)
{
var subscriptionId = requestId;
var compiler = new MatchCompiler();
var exp = compiler.BuildExpression(expression).Compile();
var sub = new Subscription(subscriptionId, exp, callback);
if (!this.subscriptions.TryAdd(subscriptionId, sub))
{
throw new Exception();
}
return(subscriptionId);
}
static void _compile(string dir, BinaryWriter rwriter)
{
var files = string.Join(" ", Directory.EnumerateFiles(dir, "*.cpp", SearchOption.AllDirectories));
var result = MatchCompiler.Compile(files);
if (!result.IsCompileSuccessful)
{
rwriter.Write(2);
rwriter.Write(Path.GetFileNameWithoutExtension(dir));
rwriter.Write("Compile Error.\n" + result.CompilerHints);
_results.Add(dir, "Compile Error.\n" + result.CompilerHints);
}
else
{
_compiledFiles.Add(dir, result.CompiledExecutablePath);
}
}
/// <summary>
/// Lists and subscribes to a query. This will fetch all rows that match the query and any subsequent matches will also be returned.
/// </summary>
/// <param name="expression">The query to subscribe to</param>
/// <param name="requestId">Request ID specified by client</param>
/// <param name="callback">Callback function used to post transactions with</param>
/// <returns>Subscription ID. used to unsubscribe and identify subscription when transactions are returned.</returns>
public async Task <Guid> ListAndSubscribe(string expression, Guid requestId, Action <Guid, Transaction> callback)
{
var subscriptionId = requestId;
var compiler = new MatchCompiler();
var exp = compiler.BuildExpression(expression).Compile();
var sub = new Subscription(subscriptionId, exp, callback);
if (!this.subscriptions.TryAdd(subscriptionId, sub))
{
return(requestId);
}
foreach (var trans in (await this.Storage.QueryAsync()).Where(exp))
{
callback(requestId, trans);
}
return(subscriptionId);
}
