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#![cfg_attr(not(feature = "std"), no_std)]
#[cfg(feature = "std")]
extern crate std as core;
use byteorder::{BigEndian, ByteOrder};
use core::convert::TryInto;
mod iter;
use iter::Bytes;
macro_rules! unwrap {
($e:expr) => {
match $e {
Some(t) => t,
None => return Status::Partial,
}
};
}
#[derive(Debug, PartialEq)]
pub enum Status {
Complete(usize),
Partial,
}
impl Status {
#[inline]
pub fn is_complete(&self) -> bool {
match *self {
Status::Complete(..) => true,
Status::Partial => false,
}
}
#[inline]
pub fn is_partial(&self) -> bool {
match *self {
Status::Complete(..) => false,
Status::Partial => true,
}
}
#[inline]
pub fn unwrap(self) -> usize {
match self {
Status::Complete(len) => len,
Status::Partial => panic!("Tried to unwrap Status::Partial"),
}
}
}
#[derive(Debug, PartialEq)]
pub enum Opcode {
Continue,
Text,
Binary,
Close,
Ping,
Pong,
Reserved,
}
impl From<u8> for Opcode {
fn from(opcode: u8) -> Opcode {
match opcode {
0 => Opcode::Continue,
1 => Opcode::Text,
2 => Opcode::Binary,
8 => Opcode::Close,
9 => Opcode::Ping,
10 => Opcode::Pong,
_ => Opcode::Reserved,
}
}
}
#[derive(Debug, PartialEq)]
pub struct Head {
pub op: Opcode,
pub finished: bool,
pub rsv: [bool; 3],
}
#[derive(Debug, PartialEq)]
pub struct Frame<'buf> {
pub head: Option<Head>,
pub mask: Option<[u8; 4]>,
pub payload: Option<&'buf [u8]>,
}
impl<'buf> Frame<'buf> {
pub const fn empty() -> Self {
Self {
head: None,
mask: None,
payload: None,
}
}
pub fn decode(&mut self, buf: &'buf [u8]) -> Status {
let mut bytes = Bytes::new(buf);
let first = unwrap!(bytes.next());
let rsv_bits = first >> 4 & 0x7u8;
let mut rsv = [false; 3];
for i in 0..3 {
rsv[2 - i] = rsv_bits >> i & 0x1u8 == 1u8;
}
self.head = Some(Head {
op: Opcode::from(first & 0xF),
finished: first_bit(first),
rsv,
});
let second = unwrap!(bytes.next());
let len = match second & 0x3F {
126 => unwrap!(bytes.slice_to(4).map(BigEndian::read_u64)),
127 => unwrap!(bytes.slice_to(8).map(BigEndian::read_u64)),
l => l as u64,
};
if first_bit(second) {
let mut mask = [0; 4];
mask.copy_from_slice(unwrap!(bytes.slice_to(4)));
self.mask = Some(mask);
}
self.payload = Some(unwrap!(bytes.slice_to(len.try_into().unwrap())));
Status::Complete(bytes.pos())
}
}
#[inline]
fn first_bit(byte: u8) -> bool {
byte >> 7 == 1u8
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn it_works() {
const BYTES: &[u8] = &[0b10100010, 0b00000011, 0b00000001, 0b00000010, 0b00000011];
let mut f = Frame::empty();
assert_eq!(Status::Complete(BYTES.len()), f.decode(BYTES));
let head = f.head.unwrap();
assert!(head.finished);
assert_eq!([false, true, false], head.rsv);
assert_eq!(3, f.payload.unwrap().len());
}
}