hunt.http.codec.http.stream.SimpleFlowControlStrategy source code

1 module hunt.http.codec.http.stream.SimpleFlowControlStrategy;
2 
3 import hunt.http.codec.http.stream.AbstractFlowControlStrategy;
4 import hunt.http.codec.http.stream.SessionSPI;
5 import hunt.http.codec.http.stream.StreamSPI;
6 
7 import hunt.http.codec.http.frame.Frame;
8 import hunt.http.codec.http.frame.WindowUpdateFrame;
9 import hunt.util.Common;
10 
11 import hunt.logging;
12 
13 
14 /**
15 */
16 class SimpleFlowControlStrategy :AbstractFlowControlStrategy {
17     this() {
18         this(DEFAULT_WINDOW_SIZE);
19     }
20 
21     this(int initialStreamSendWindow) {
22         super(initialStreamSendWindow);
23     }
24 
25     override
26     void onDataConsumed(SessionSPI session, StreamSPI stream, int length) {
27         if (length <= 0)
28             return;
29 
30         // This is the simple algorithm for flow control.
31         // This method is called when a whole flow controlled frame has been
32         // consumed.
33         // We send a WindowUpdate every time, even if the frame was very small.
34 
35         WindowUpdateFrame sessionFrame = new WindowUpdateFrame(0, length);
36         session.updateRecvWindow(length);
37         version(HUNT_DEBUG)
38             tracef("Data consumed, increased session recv window by %s for %s", length, session);
39 
40         Frame[] streamFrame = Frame.EMPTY_ARRAY;
41         if (stream !is null) {
42             if (stream.isRemotelyClosed()) {
43                 version(HUNT_DEBUG) {
44                     tracef("Data consumed, ignoring update stream recv window by %s for remotely closed %s", length, stream);
45                 }
46             } else {
47                 streamFrame = new Frame[1];
48                 streamFrame[0] = new WindowUpdateFrame(stream.getId(), length);
49                 stream.updateRecvWindow(length);
50                 version(HUNT_DEBUG)
51                     tracef("Data consumed, increased stream recv window by %s for %s", length, stream);
52             }
53         }
54 
55         session.frames(stream, Callback.NOOP, sessionFrame, streamFrame);
56     }
57 }