TaskManager.RunTask() & TFuture.Chain(Proc)

Src/Myc.Trade.DataStream.pas

@@ -172,29 +172,6 @@ type
         function ParseFileName(const FileName: string): TAuraDataFile; override;
     end;
 
-    // Implements a data stream that reads from Aura-specific historical data files.
-    TAuraFileLoader<T: record> = class(TInterfacedObject)
-        type
-            TDataProc = reference to procedure(const Values: TArray<TDataPoint<T>>);
-
-    private
-        class procedure LoadFile(
-            DataServer: TAuraDataServer<T>;
-            currFile: TAuraDataFile;
-            Terminated: TState;
-            Done: TLatch;
-            Proc: TDataProc
-        );
-
-    public
-        class function LoadData(
-            DataServer: TAuraDataServer<T>;
-            const Symbol: String;
-            const Terminate: TSignal;
-            const Proc: TDataProc
-        ): TState;
-    end;
-
 implementation
 
 uses
@@ -413,12 +390,9 @@ begin
     var capProc := Proc;
     var terminated := TFlag.CreateObserver(Terminate).State;
 
-    var firstFile := FindFirstFile(Symbol);
-
-    var done := TLatch.CreateLatch(1);
-    Result := done.State;
-
-    TaskManager.CreateTask(firstFile.Done, procedure begin LoadFile(firstFile.Value, terminated, capProc).Subscribe(done); end);
+    Result :=
+        FindFirstFile(Symbol)
+            .Chain(function(const FirstFile: TAuraDataFile): TState begin Result := LoadFile(FirstFile, terminated, capProc); end);
 end;
 
 function TAuraDataServer<T>.LoadDataFile(const DataFile: TAuraDataFile): TFuture<TArray<TDataPoint<T>>>;
@@ -431,19 +405,16 @@ begin
     if not currFile.IsValid or Terminated.IsSet then
         exit(TState.Null);
 
-    var done := TLatch.CreateLatch(1);
-    Result := done.State;
-
     var data := FCachedFiles.GetOrAdd(currFile.GetFullFileName);
 
-    TaskManager.CreateTask(
-        data.Done,
-        procedure
-        begin
-            Proc(data.Value, Terminated);
-            LoadFile(currFile.GetNextFile, Terminated, Proc).Subscribe(done);
-        end
-    );
+    Result :=
+        data.Chain(
+            function(const Data: TArray<TDataPoint<T>>): TState
+            begin
+                Proc(Data, Terminated);
+                Result := LoadFile(currFile.GetNextFile, Terminated, Proc);
+            end
+        );
 end;
 
 { TAuraFileStream<T> }
@@ -792,49 +763,4 @@ begin
     end;
 end;
 
-class function TAuraFileLoader<T>.LoadData(
-    DataServer: TAuraDataServer<T>;
-    const Symbol: String;
-    const Terminate: TSignal;
-    const Proc: TDataProc
-): TState;
-begin
-    var capProc := Proc;
-    var terminated := TFlag.CreateObserver(Terminate).State;
-
-    var firstFile := DataServer.FindFirstFile(Symbol);
-
-    var done := TLatch.CreateLatch(1);
-
-    TaskManager.CreateTask(firstFile.Done, procedure begin LoadFile(DataServer, firstFile.Value, terminated, done, capProc); end);
-
-    Result := done.State;
-end;
-
-class procedure TAuraFileLoader<T>.LoadFile(
-    DataServer: TAuraDataServer<T>;
-    currFile: TAuraDataFile;
-    Terminated: TState;
-    Done: TLatch;
-    Proc: TDataProc
-);
-begin
-    if not currFile.IsValid or Terminated.IsSet then
-    begin
-        Done.Notify;
-        exit;
-    end;
-
-    var data := DataServer.LoadDataFile(currFile);
-
-    TaskManager.CreateTask(
-        data.Done,
-        procedure
-        begin
-            Proc(data.Value);
-            LoadFile(DataServer, currFile.GetNextFile, Terminated, Done, Proc);
-        end
-    );
-end;
-
 end.