use crate::{    client::{Error, MessageKind, WriteMode},    Protocol,};use std::{    io,    ops::{Deref, DerefMut},}; /// A function `f(is_error, text)` receiving progress or error information.pub type HandleProgress = Box<dyn FnMut(bool, &[u8])>; /// A [`Write`][io::Write] implementation optimized for writing packet lines./// A type implementing `Write` for packet lines, which when done can be transformed into a `Read` for/// obtaining the response.pub struct RequestWriter<'a> {    on_into_read: MessageKind,    pub(crate) writer: git_packetline::Writer<Box<dyn io::Write + 'a>>,    pub(crate) reader: Box<dyn ExtendedBufRead + 'a>,} impl<'a> io::Write for RequestWriter<'a> {    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {        self.writer.write(buf)    }     fn flush(&mut self) -> io::Result<()> {        self.writer.flush()    }} impl<'a> RequestWriter<'a> {    /// Create a new instance from a `writer` (commonly a socket), a `reader` into which to transform once the    /// writes are finished, along with configuration for the `write_mode` and information about which message to write    /// when this instance is converted into a `reader` to read the request's response.    pub fn new_from_bufread<W: io::Write + 'a>(        writer: W,        reader: Box<dyn ExtendedBufRead + 'a>,        write_mode: WriteMode,        on_into_read: MessageKind,    ) -> Self {        let mut writer = git_packetline::Writer::new(Box::new(writer) as Box<dyn io::Write>);        match write_mode {            WriteMode::Binary => writer.enable_binary_mode(),            WriteMode::OneLfTerminatedLinePerWriteCall => writer.enable_text_mode(),        }        RequestWriter {            on_into_read,            writer,            reader,        }    }     /// Discard the ability to write and turn this instance into the reader for obtaining the other side's response.    pub fn into_read(mut self) -> io::Result<Box<dyn ExtendedBufRead + 'a>> {        self.write_message(self.on_into_read)?;        Ok(self.reader)    }     /// Write the given message as packet line.    pub fn write_message(&mut self, message: MessageKind) -> io::Result<()> {        match message {            MessageKind::Flush => git_packetline::PacketLine::Flush.to_write(self.writer.inner_mut()),            MessageKind::Delimiter => git_packetline::PacketLine::Delimiter.to_write(self.writer.inner_mut()),            MessageKind::ResponseEnd => git_packetline::PacketLine::ResponseEnd.to_write(self.writer.inner_mut()),            MessageKind::Text(t) => git_packetline::immutable::Text::from(t).to_write(self.writer.inner_mut()),        }        .map(|_| ())    }} /// This trait exists to get a version of a `git_packetline::Provider` without type parameters./// For the sake of usability, it also implements [`std::io::BufRead`] making it trivial to (eventually)/// read pack files while keeping the possibility to read individual lines with low overhead.pub trait ExtendedBufRead: io::BufRead {    /// Set the handler to which progress will be delivered.    ///    /// Note that this is only possible if packet lines are sent in side band mode.    fn set_progress_handler(&mut self, handle_progress: Option<HandleProgress>);    /// Peek the next data packet line.    fn peek_data_line(&mut self) -> Option<io::Result<Result<&[u8], Error>>>;    /// Resets the reader to allow reading past a previous stop, and sets delimiters according to the    /// given protocol.    fn reset(&mut self, version: Protocol);    /// Return the kind of message at which the reader stopped.    fn stopped_at(&self) -> Option<MessageKind>;} impl<'a, T: ExtendedBufRead + ?Sized + 'a> ExtendedBufRead for Box<T> {    fn set_progress_handler(&mut self, handle_progress: Option<HandleProgress>) {        self.deref_mut().set_progress_handler(handle_progress)    }     fn peek_data_line(&mut self) -> Option<io::Result<Result<&[u8], Error>>> {        self.deref_mut().peek_data_line()    }     fn reset(&mut self, version: Protocol) {        self.deref_mut().reset(version)    }     fn stopped_at(&self) -> Option<MessageKind> {        self.deref().stopped_at()    }} impl<'a, T: io::Read> ExtendedBufRead for git_packetline::read::WithSidebands<'a, T, HandleProgress> {    fn set_progress_handler(&mut self, handle_progress: Option<HandleProgress>) {        self.set_progress_handler(handle_progress)    }    fn peek_data_line(&mut self) -> Option<io::Result<Result<&[u8], Error>>> {        match self.peek_data_line() {            Some(Ok(Ok(line))) => Some(Ok(Ok(line))),            Some(Ok(Err(err))) => Some(Ok(Err(err.into()))),            Some(Err(err)) => Some(Err(err)),            None => None,        }    }    fn reset(&mut self, version: Protocol) {        match version {            Protocol::V1 => self.reset_with(&[git_packetline::PacketLine::Flush]),            Protocol::V2 => {                self.reset_with(&[git_packetline::PacketLine::Delimiter, git_packetline::PacketLine::Flush])            }        }    }    fn stopped_at(&self) -> Option<MessageKind> {        self.stopped_at().map(|l| match l {            git_packetline::PacketLine::Flush => MessageKind::Flush,            git_packetline::PacketLine::Delimiter => MessageKind::Delimiter,            git_packetline::PacketLine::ResponseEnd => MessageKind::ResponseEnd,            git_packetline::PacketLine::Data(_) => unreachable!("data cannot be a delimiter"),        })    }}