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use rand::Rng;
use crate::*;
impl<T: Message + ?Sized> Message for &T {
#[inline]
fn encode<const SIDE: bool>(&self, writer: &mut Vec<u8>) {
T::encode::<SIDE>(self, writer)
}
}
impl Message for str {
#[inline]
fn encode<const SIDE: bool>(&self, writer: &mut Vec<u8>) {
encode::<SIDE>(writer, true, 1, self.as_bytes());
}
}
impl Message for [u8] {
#[inline]
fn encode<const SIDE: bool>(&self, writer: &mut Vec<u8>) {
encode::<SIDE>(writer, true, 2, self);
}
}
impl<const N: usize> Message for [u8; N] {
#[inline]
fn encode<const SIDE: bool>(&self, writer: &mut Vec<u8>) {
encode::<SIDE>(writer, true, 2, self);
}
}
impl CloseFrame for () {
type Frame = Box<[u8]>;
fn encode<const SIDE: bool>(self) -> Self::Frame {
if SIDE == SERVER {
Box::new([136, 0])
} else {
Box::new([136, 128, 0, 0, 0, 0])
}
}
}
impl CloseFrame for u16 {
type Frame = Vec<u8>;
fn encode<const SIDE: bool>(self) -> Self::Frame {
let mut bytes = Vec::new();
encode::<SIDE>(&mut bytes, true, 8, &self.to_be_bytes());
bytes
}
}
impl CloseFrame for CloseCode {
type Frame = Vec<u8>;
fn encode<const SIDE: bool>(self) -> Self::Frame {
CloseFrame::encode::<SIDE>(u16::from(self))
}
}
impl<Code, Msg> CloseFrame for (Code, Msg)
where
Code: Into<u16>,
Msg: AsRef<[u8]>,
{
type Frame = Vec<u8>;
fn encode<const SIDE: bool>(self) -> Self::Frame {
let (code, reason) = (self.0.into(), self.1.as_ref());
let mut data = Vec::with_capacity(2 + reason.len());
data.extend_from_slice(&code.to_be_bytes());
data.extend_from_slice(reason);
let mut bytes = Vec::new();
encode::<SIDE>(&mut bytes, true, 8, &data);
bytes
}
}
impl CloseFrame for &str {
type Frame = Vec<u8>;
fn encode<const SIDE: bool>(self) -> Self::Frame {
CloseFrame::encode::<SIDE>((CloseCode::Normal, self))
}
}
pub(crate) fn encode<const SIDE: bool>(writer: &mut Vec<u8>, fin: bool, opcode: u8, data: &[u8]) {
let data_len = data.len();
writer.reserve(if SERVER == SIDE { 10 } else { 14 } + data_len);
unsafe {
let filled = writer.len();
let start = writer.as_mut_ptr().add(filled);
let mask_bit = if SERVER == SIDE { 0 } else { 0x80 };
start.write(((fin as u8) << 7) | opcode);
let len = if data_len < 126 {
start.add(1).write(mask_bit | data_len as u8);
2
} else if data_len < 65536 {
let [b2, b3] = (data_len as u16).to_be_bytes();
start.add(1).write(mask_bit | 126);
start.add(2).write(b2);
start.add(3).write(b3);
4
} else {
let [b2, b3, b4, b5, b6, b7, b8, b9] = (data_len as u64).to_be_bytes();
start.add(1).write(mask_bit | 127);
start.add(2).write(b2);
start.add(3).write(b3);
start.add(4).write(b4);
start.add(5).write(b5);
start.add(6).write(b6);
start.add(7).write(b7);
start.add(8).write(b8);
start.add(9).write(b9);
10
};
let header_len = if SERVER == SIDE {
std::ptr::copy_nonoverlapping(data.as_ptr(), start.add(len), data_len);
len
} else {
let mut rng = rand::thread_rng();
let mask = rng.gen::<u32>().to_ne_bytes();
let [a, b, c, d] = mask;
start.add(len).write(a);
start.add(len + 1).write(b);
start.add(len + 2).write(c);
start.add(len + 3).write(d);
let dist = start.add(len + 4);
for (index, byte) in data.iter().enumerate() {
dist.add(index).write(byte ^ mask.get_unchecked(index % 4));
}
len + 4
};
writer.set_len(filled + header_len + data_len);
}
}
#[cfg(test)]
mod encode {
use super::*;
const DATA: &[u8] = b"Hello";
#[test]
fn unmasked_txt_msg() {
let mut bytes = vec![];
encode::<SERVER>(&mut bytes, true, 1, DATA);
assert_eq!(bytes, [0x81, 0x05, 0x48, 0x65, 0x6c, 0x6c, 0x6f]);
}
#[test]
fn fragmented_unmasked_txt_msg() {
let mut bytes = vec![];
encode::<SERVER>(&mut bytes, false, 1, b"Hel");
encode::<SERVER>(&mut bytes, true, 0, b"lo");
assert_eq!(
bytes,
[
0x01, 0x03, 0x48, 0x65, 0x6c, 0x80, 0x02, 0x6c, 0x6f, ]
);
}
#[test]
fn unmasked_ping_req() {
let mut bytes = vec![];
encode::<SERVER>(&mut bytes, true, 9, DATA);
assert_eq!(bytes, [0x89, 0x05, 0x48, 0x65, 0x6c, 0x6c, 0x6f,]);
}
}