Files
h2/src/frame/head.rs
2017-06-26 22:25:25 -07:00

110 lines
2.5 KiB
Rust

use super::Error;
use bytes::{BufMut, BigEndian};
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct Head {
kind: Kind,
flag: u8,
stream_id: StreamId,
}
#[repr(u8)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum Kind {
Data = 0,
Headers = 1,
Priority = 2,
Reset = 3,
Settings = 4,
PushPromise = 5,
Ping = 6,
GoAway = 7,
WindowUpdate = 8,
Continuation = 9,
Unknown,
}
pub type StreamId = u32;
const STREAM_ID_MASK: StreamId = 0x80000000;
// ===== impl Head =====
impl Head {
pub fn new(kind: Kind, flag: u8, stream_id: StreamId) -> Head {
Head {
kind: kind,
flag: flag,
stream_id: stream_id,
}
}
/// Parse an HTTP/2.0 frame header
pub fn parse(header: &[u8]) -> Head {
Head {
kind: Kind::new(header[3]),
flag: header[4],
stream_id: parse_stream_id(&header[5..]),
}
}
pub fn stream_id(&self) -> u32 {
self.stream_id
}
pub fn kind(&self) -> Kind {
self.kind
}
pub fn flag(&self) -> u8 {
self.flag
}
pub fn encode_len(&self) -> usize {
super::HEADER_LEN
}
pub fn encode<T: BufMut>(&self, payload_len: usize, dst: &mut T) {
debug_assert!(self.encode_len() <= dst.remaining_mut());
debug_assert!(self.stream_id & STREAM_ID_MASK == 0);
dst.put_uint::<BigEndian>(payload_len as u64, 3);
dst.put_u8(self.kind as u8);
dst.put_u8(self.flag);
dst.put_u32::<BigEndian>(self.stream_id);
}
}
/// Parse the next 4 octets in the given buffer, assuming they represent an
/// HTTP/2 stream ID. This means that the most significant bit of the first
/// octet is ignored and the rest interpreted as a network-endian 31-bit
/// integer.
#[inline]
pub fn parse_stream_id(buf: &[u8]) -> StreamId {
/// TODO: Move this onto the StreamId type?
let unpacked = unpack_octets_4!(buf, 0, u32);
// Now clear the most significant bit, as that is reserved and MUST be ignored when received.
unpacked & !STREAM_ID_MASK
}
// ===== impl Kind =====
impl Kind {
pub fn new(byte: u8) -> Kind {
return match byte {
0 => Kind::Data,
1 => Kind::Headers,
2 => Kind::Priority,
3 => Kind::Reset,
4 => Kind::Settings,
5 => Kind::PushPromise,
6 => Kind::Ping,
7 => Kind::GoAway,
8 => Kind::WindowUpdate,
9 => Kind::Continuation,
_ => Kind::Unknown,
}
}
}