static void Main(string[] args)
{
// The StreamInsight engine is a server that can be embedded (in-memory) or remote (e.g. the Azure Service).
// We first use Server.Create to create a server instance and return a handle to that instance.
using (Server server = Server.Create("Default"))
{
Application application = server.CreateApplication("app");
// We will be building a query that takes a stream of SensorReading events.
// It will work the same way on real-time data or past recorded events.
IQStreamable <SensorReading> inputStream = null;
Console.WriteLine("Press L for Live or H for Historic Data");
ConsoleKeyInfo key = Console.ReadKey();
Console.WriteLine();
if (key.Key == ConsoleKey.L)
{
inputStream = CreateStream(application, true);
}
else if (key.Key == ConsoleKey.H)
{
inputStream = CreateStream(application, false);
}
else
{
Console.WriteLine("invalid key");
return;
}
// The query is detecting when a threshold is crossed upwards.
// See the Visio drawing TresholdCrossedUpward.vsd for the intuition.
int threshold = 42;
// Alter all events 1 sec in the future.
var alteredForward = inputStream.AlterEventStartTime(s => s.StartTime.AddSeconds(1));
// Compare each event that occurs at input with the previous event.
// Note that, this one works for strictly ordered, strictly (e.g 1 sec) regular streams.
var crossedThreshold = from evt in inputStream
from prev in alteredForward
where prev.Value <threshold && evt.Value> threshold
select new
{
Time = evt.Time,
Low = prev.Value,
High = evt.Value
};
foreach (var outputSample in crossedThreshold.ToEnumerable())
{
Console.WriteLine(outputSample);
}
Console.WriteLine("Done. Press ENTER to terminate");
Console.ReadLine();
}
}
static void Main()
{
using (Server server = Server.Create("Default")) {
Application application = server.CreateApplication("app");
IQStreamable <YahooQuote> inputStream = null;
Console.WriteLine("Press L for Live or H for Historic Data");
ConsoleKeyInfo key = Console.ReadKey();
Console.WriteLine();
if (key.Key == ConsoleKey.L)
{
inputStream = CreateStream(application, true);
}
else if (key.Key == ConsoleKey.H)
{
inputStream = CreateStream(application, false);
}
else
{
Console.WriteLine("Invalid Key");
return;
}
decimal threshold = new decimal(14.00);
var alteredForward = inputStream.AlterEventStartTime(s => s.StartTime.AddSeconds(1));
var crossedThreshold = from evt in inputStream
from prev in alteredForward
where prev.LastTradePrice <threshold && evt.LastTradePrice> threshold
select new {
LastUpdate = evt.LastUpdate,
Low = prev.LastTradePrice,
High = evt.LastTradePrice
};
foreach (var outputSample in crossedThreshold.ToEnumerable())
{
Console.WriteLine(outputSample);
}
Console.WriteLine("Done. Press ENTER to terminate");
Console.ReadLine();
}
}
static void Main(string[] args)
{
Server server = Server.Create("MyInstance");
Application application = server.CreateApplication("app");
Console.WriteLine("server+application ready");
DateTime startTime = new DateTime(2019, 1, 1);
IQStreamable <SensorReading> inputStream =
application.DefineObservable(() => SimulateLiveData()).ToPointStreamable(
r => PointEvent <SensorReading> .CreateInsert(startTime.AddSeconds(r.Time), r),
AdvanceTimeSettings.StrictlyIncreasingStartTime);
int threshold = 42;
// Alter all events 1 sec in the future.
var alteredForward = inputStream.AlterEventStartTime(s => s.StartTime.AddSeconds(1));
Console.WriteLine("stream ready");
// Compare each event that occurs at input with the previous event.
// Note that, this one works for strictly ordered, strictly (e.g 1 sec) regular streams.
var crossedThreshold = from evt in inputStream
from prev in alteredForward
where prev.Value <threshold && evt.Value> threshold
select new
{
Time = evt.Time,
Low = prev.Value,
High = evt.Value
};
Console.WriteLine("query ready");
var query = crossedThreshold.ToEnumerable(); // lazy初始化
foreach (var outputSample in query) // 迭代访问query的过程会触发inputStream的产生
{
Console.WriteLine(outputSample); // 打印outputSample, 也就是select new的结果
}
Console.WriteLine("Done. Press ENTER to terminate");
application.Delete();
server.Dispose();
}
