use cid::Cid;
use integer_encoding::VarIntWriter;
use super::{error::Error, header::CarHeader};
#[derive(Debug)]
pub struct CarWriter<W> {
header: CarHeader,
writer: W,
cid_buffer: Vec<u8>,
is_header_written: bool,
}
impl<W> CarWriter<W>
where
W: std::io::Write + Send + Unpin,
{
pub fn new(header: CarHeader, writer: W) -> Self {
CarWriter {
header,
writer,
cid_buffer: Vec::new(),
is_header_written: false,
}
}
pub fn write<T>(&mut self, cid: Cid, data: T) -> Result<(), Error>
where
T: AsRef<[u8]>,
{
if !self.is_header_written {
let header_bytes = self.header.encode()?;
self.writer.write_varint(header_bytes.len())?;
self.writer.write_all(&header_bytes)?;
self.is_header_written = true;
}
self.cid_buffer.clear();
cid.write_bytes(&mut self.cid_buffer)?;
let data = data.as_ref();
let len = self.cid_buffer.len() + data.len();
self.writer.write_varint(len)?;
self.writer.write_all(&self.cid_buffer)?;
self.writer.write_all(data)?;
Ok(())
}
pub fn finish(mut self) -> Result<W, Error> {
self.flush()?;
Ok(self.writer)
}
pub fn flush(&mut self) -> Result<(), Error> {
self.writer.flush()?;
Ok(())
}
pub fn into_inner(self) -> W {
self.writer
}
}