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proto_async: always consume one byte in recv

This commit is contained in:
Sebastien Bourdeauducq 2020-07-19 16:07:55 +08:00
parent 523524c319
commit 3ec9788eb1
1 changed files with 70 additions and 36 deletions
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106
src/runtime/src/proto_async.rs
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@ -5,23 +5,39 @@ use core::cell::RefCell;
use libboard_zynq::smoltcp;
use libasync::smoltcp::TcpStream;
// TODO: use byteorder, make it more like libio
type Result<T> = core::result::Result<T, smoltcp::Error>;
enum RecvState<T> {
NeedsMore(usize, T), // bytes consumed so far, partial result
Completed(T), // final result
}
pub async fn expect(stream: &TcpStream, pattern: &[u8]) -> Result<bool> {
stream.recv(|buf| {
for (i, b) in buf.iter().enumerate() {
if *b == pattern[i] {
if i + 1 == pattern.len() {
return Poll::Ready((i + 1, Ok(true)));
let mut state = RecvState::NeedsMore(0, true);
loop {
state = stream.recv(|buf| {
let mut consumed = 0;
if let RecvState::NeedsMore(mut cur_index, _) = state {
for b in buf.iter() {
consumed += 1;
if *b == pattern[cur_index] {
if cur_index + 1 == pattern.len() {
return Poll::Ready((consumed, RecvState::Completed(true)));
}
} else {
return Poll::Ready((consumed, RecvState::Completed(false)));
}
cur_index += 1;
}
Poll::Ready((consumed, RecvState::NeedsMore(cur_index, true)))
} else {
return Poll::Ready((i + 1, Ok(false)));
unreachable!();
}
}).await?;
if let RecvState::Completed(result) = state {
return Ok(result);
}
Poll::Pending
}).await?
}
}
pub async fn read_bool(stream: &TcpStream) -> Result<bool> {
@ -37,37 +53,55 @@ pub async fn read_i8(stream: &TcpStream) -> Result<i8> {
}
pub async fn read_i32(stream: &TcpStream) -> Result<i32> {
Ok(stream.recv(|buf| {
if buf.len() >= 4 {
let value =
((buf[0] as i32) << 24)
| ((buf[1] as i32) << 16)
| ((buf[2] as i32) << 8)
| (buf[3] as i32);
Poll::Ready((4, value))
} else {
Poll::Pending
let mut state = RecvState::NeedsMore(0, 0);
loop {
state = stream.recv(|buf| {
let mut consumed = 0;
if let RecvState::NeedsMore(mut cur_index, mut cur_value) = state {
for b in buf.iter() {
consumed += 1;
cur_index += 1;
cur_value <<= 8;
cur_value |= *b as i32;
if cur_index == 4 {
return Poll::Ready((consumed, RecvState::Completed(cur_value)));
}
}
Poll::Ready((consumed, RecvState::NeedsMore(cur_index, cur_value)))
} else {
unreachable!();
}
}).await?;
if let RecvState::Completed(result) = state {
return Ok(result);
}
}).await?)
}
}
pub async fn read_i64(stream: &TcpStream) -> Result<i64> {
Ok(stream.recv(|buf| {
if buf.len() >= 8 {
let value =
((buf[0] as i64) << 56)
| ((buf[1] as i64) << 48)
| ((buf[2] as i64) << 40)
| ((buf[3] as i64) << 32)
| ((buf[4] as i64) << 24)
| ((buf[5] as i64) << 16)
| ((buf[6] as i64) << 8)
| (buf[7] as i64);
Poll::Ready((8, value))
} else {
Poll::Pending
let mut state = RecvState::NeedsMore(0, 0);
loop {
state = stream.recv(|buf| {
let mut consumed = 0;
if let RecvState::NeedsMore(mut cur_index, mut cur_value) = state {
for b in buf.iter() {
consumed += 1;
cur_index += 1;
cur_value <<= 8;
cur_value |= *b as i64;
if cur_index == 8 {
return Poll::Ready((consumed, RecvState::Completed(cur_value)));
}
}
Poll::Ready((consumed, RecvState::NeedsMore(cur_index, cur_value)))
} else {
unreachable!();
}
}).await?;
if let RecvState::Completed(result) = state {
return Ok(result);
}
}).await?)
}
}
pub async fn read_chunk(stream: &TcpStream, destination: &mut [u8]) -> Result<()> {