use std::io;
use bstr::ByteSlice;
use futures_io::AsyncRead;
use futures_lite::AsyncReadExt;
use crate::{
decode,
read::{ExhaustiveOutcome, WithSidebands},
PacketLineRef, StreamingPeekableIter, MAX_LINE_LEN, U16_HEX_BYTES,
};
/// Non-IO methods
impl<T> StreamingPeekableIter<T>
where
T: AsyncRead + Unpin,
{
#[allow(clippy::needless_lifetimes)] // TODO: remove once this is clippy false positive is fixed
async fn read_line_inner<'a>(
reader: &mut T,
buf: &'a mut [u8],
) -> io::Result<Result<PacketLineRef<'a>, decode::Error>> {
let (hex_bytes, data_bytes) = buf.split_at_mut(4);
reader.read_exact(hex_bytes).await?;
let num_data_bytes = match decode::hex_prefix(hex_bytes) {
Ok(decode::PacketLineOrWantedSize::Line(line)) => return Ok(Ok(line)),
Ok(decode::PacketLineOrWantedSize::Wanted(additional_bytes)) => additional_bytes as usize,
Err(err) => return Ok(Err(err)),
};
let (data_bytes, _) = data_bytes.split_at_mut(num_data_bytes);
reader.read_exact(data_bytes).await?;
match decode::to_data_line(data_bytes) {
Ok(line) => Ok(Ok(line)),
Err(err) => Ok(Err(err)),
}
}
/// This function is needed to help the borrow checker allow us to return references all the time
/// It contains a bunch of logic shared between peek and read_line invocations.
async fn read_line_inner_exhaustive<'a>(
reader: &mut T,
buf: &'a mut Vec<u8>,
delimiters: &[PacketLineRef<'static>],
fail_on_err_lines: bool,
buf_resize: bool,
) -> ExhaustiveOutcome<'a> {
(
false,
None,
Some(match Self::read_line_inner(reader, buf).await {
Ok(Ok(line)) => {
if delimiters.contains(&line) {
let stopped_at = delimiters.iter().find(|l| **l == line).cloned();
buf.clear();
return (true, stopped_at, None);
} else if fail_on_err_lines {
if let Some(err) = line.check_error() {
let err = err.0.as_bstr().to_owned();
buf.clear();
return (
true,
None,
Some(Err(io::Error::new(
io::ErrorKind::Other,
crate::read::Error { message: err },
))),
);
}
}
let len = line
.as_slice()
.map(|s| s.len() + U16_HEX_BYTES)
.unwrap_or(U16_HEX_BYTES);
if buf_resize {
buf.resize(len, 0);
}
Ok(Ok(crate::decode(buf).expect("only valid data here")))
}
Ok(Err(err)) => {
buf.clear();
Ok(Err(err))
}
Err(err) => {
buf.clear();
Err(err)
}
}),
)
}
/// Read a packet line into the internal buffer and return it.
///
/// Returns `None` if the end of iteration is reached because of one of the following:
///
/// * natural EOF
/// * ERR packet line encountered if [`fail_on_err_lines()`][StreamingPeekableIter::fail_on_err_lines()] is true.
/// * A `delimiter` packet line encountered
pub async fn read_line(&mut self) -> Option<io::Result<Result<PacketLineRef<'_>, decode::Error>>> {
if self.is_done {
return None;
}
if !self.peek_buf.is_empty() {
std::mem::swap(&mut self.peek_buf, &mut self.buf);
self.peek_buf.clear();
Some(Ok(Ok(crate::decode(&self.buf).expect("only valid data in peek buf"))))
} else {
if self.buf.len() != MAX_LINE_LEN {
self.buf.resize(MAX_LINE_LEN, 0);
}
let (is_done, stopped_at, res) = Self::read_line_inner_exhaustive(
&mut self.read,
&mut self.buf,
self.delimiters,
self.fail_on_err_lines,
false,
)
.await;
self.is_done = is_done;
self.stopped_at = stopped_at;
res
}
}
/// Peek the next packet line without consuming it.
///
/// Multiple calls to peek will return the same packet line, if there is one.
pub async fn peek_line(&mut self) -> Option<io::Result<Result<PacketLineRef<'_>, decode::Error>>> {
if self.is_done {
return None;
}
if self.peek_buf.is_empty() {
self.peek_buf.resize(MAX_LINE_LEN, 0);
let (is_done, stopped_at, res) = Self::read_line_inner_exhaustive(
&mut self.read,
&mut self.peek_buf,
self.delimiters,
self.fail_on_err_lines,
true,
)
.await;
self.is_done = is_done;
self.stopped_at = stopped_at;
res
} else {
Some(Ok(Ok(crate::decode(&self.peek_buf).expect("only valid data here"))))
}
}
/// Same as [`as_read_with_sidebands(…)`][StreamingPeekableIter::as_read_with_sidebands()], but for channels without side band support.
///
/// Due to the preconfigured function type this method can be called without 'turbofish'.
pub fn as_read(&mut self) -> WithSidebands<'_, T, fn(bool, &[u8])> {
WithSidebands::new(self)
}
/// Return this instance as implementor of [`Read`][io::Read] assuming side bands to be used in all received packet lines.
/// Each invocation of [`read_line()`][io::BufRead::read_line()] returns a packet line.
///
/// Progress or error information will be passed to the given `handle_progress(is_error, text)` function, with `is_error: bool`
/// being true in case the `text` is to be interpreted as error.
///
/// _Please note_ that side bands need to be negotiated with the server.
pub fn as_read_with_sidebands<F: FnMut(bool, &[u8]) + Unpin>(
&mut self,
handle_progress: F,
) -> WithSidebands<'_, T, F> {
WithSidebands::with_progress_handler(self, handle_progress)
}
/// Same as [`as_read_with_sidebands(…)`][StreamingPeekableIter::as_read_with_sidebands()], but for channels without side band support.
///
/// The type parameter `F` needs to be configured for this method to be callable using the 'turbofish' operator.
/// Use [`as_read()`][StreamingPeekableIter::as_read()].
pub fn as_read_without_sidebands<F: FnMut(bool, &[u8]) + Unpin>(&mut self) -> WithSidebands<'_, T, F> {
WithSidebands::without_progress_handler(self)
}
}