1 | use crate::frame::{self, Error, Head, Kind, StreamId}; |
2 | |
3 | use bytes::BufMut; |
4 | |
5 | const SIZE_INCREMENT_MASK: u32 = 1 << 31; |
6 | |
7 | #[derive (Debug, Copy, Clone, Eq, PartialEq)] |
8 | pub struct WindowUpdate { |
9 | stream_id: StreamId, |
10 | size_increment: u32, |
11 | } |
12 | |
13 | impl WindowUpdate { |
14 | pub fn new(stream_id: StreamId, size_increment: u32) -> WindowUpdate { |
15 | WindowUpdate { |
16 | stream_id, |
17 | size_increment, |
18 | } |
19 | } |
20 | |
21 | pub fn stream_id(&self) -> StreamId { |
22 | self.stream_id |
23 | } |
24 | |
25 | pub fn size_increment(&self) -> u32 { |
26 | self.size_increment |
27 | } |
28 | |
29 | /// Builds a `WindowUpdate` frame from a raw frame. |
30 | pub fn load(head: Head, payload: &[u8]) -> Result<WindowUpdate, Error> { |
31 | debug_assert_eq!(head.kind(), crate::frame::Kind::WindowUpdate); |
32 | if payload.len() != 4 { |
33 | return Err(Error::BadFrameSize); |
34 | } |
35 | |
36 | // Clear the most significant bit, as that is reserved and MUST be ignored |
37 | // when received. |
38 | let size_increment = unpack_octets_4!(payload, 0, u32) & !SIZE_INCREMENT_MASK; |
39 | |
40 | if size_increment == 0 { |
41 | return Err(Error::InvalidWindowUpdateValue); |
42 | } |
43 | |
44 | Ok(WindowUpdate { |
45 | stream_id: head.stream_id(), |
46 | size_increment, |
47 | }) |
48 | } |
49 | |
50 | pub fn encode<B: BufMut>(&self, dst: &mut B) { |
51 | tracing::trace!("encoding WINDOW_UPDATE; id= {:?}" , self.stream_id); |
52 | let head = Head::new(Kind::WindowUpdate, 0, self.stream_id); |
53 | head.encode(4, dst); |
54 | dst.put_u32(self.size_increment); |
55 | } |
56 | } |
57 | |
58 | impl<B> From<WindowUpdate> for frame::Frame<B> { |
59 | fn from(src: WindowUpdate) -> Self { |
60 | frame::Frame::WindowUpdate(src) |
61 | } |
62 | } |
63 | |