use std::io; use bstr::ByteSlice; use crate::{    decode,    read::{ExhaustiveOutcome, WithSidebands},    PacketLineRef, StreamingPeekableIter, MAX_LINE_LEN, U16_HEX_BYTES,}; /// Non-IO methodsimpl<T> StreamingPeekableIter<T>where    T: io::Read,{    fn read_line_inner<'a>(        reader: &mut T,        buf: &'a mut Vec<u8>,    ) -> io::Result<Result<PacketLineRef<'a>, decode::Error>> {        let (hex_bytes, data_bytes) = buf.split_at_mut(4);        reader.read_exact(hex_bytes)?;        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)?;        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.    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) {                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_string();                            buf.clear();                            return (true, None, Some(Err(io::Error::new(io::ErrorKind::Other, 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 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,            );            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 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,            );            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"))))        }    }     /// 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])>(&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])>(&mut self) -> WithSidebands<'_, T, F> {        WithSidebands::without_progress_handler(self)    }     /// 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)    }}