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use tokio::io::{AsyncWrite, AsyncWriteExt};
use super::AsyncInlinable;
#[async_trait::async_trait]
pub trait AsyncInlinableWrite: AsyncWrite + Send + Unpin {
#[inline]
/// Write `usize` length as little endian `N` bytes.
async fn write_len_with_width<const N: usize>(&mut self, len: usize) -> std::io::Result<usize> {
self.write_all(&len.to_le_bytes()[0..N]).await?;
Ok(N)
}
#[inline]
/// Write inlined bytes to writer with specific length width `N`.
///
/// The inlined bytes are constructed as:
///
/// ```text
/// +--------------+-----------------+
/// | len: N bytes | data: len bytes |
/// +--------------+-----------------+
/// ```
///
/// ## Safety
///
/// Write inlined bytes may not be safe if the input bytes length overflows to the width.
/// For example, write `256` bytes with length width `1` is not safe.
async fn write_inlined_bytes<const N: usize>(
&mut self,
bytes: &[u8],
) -> std::io::Result<usize> {
debug_assert_eq!(bytes.len() >> (N * 8), 0); // bytes.len() < (2 ^ (8 * N))
let len = &bytes.len().to_le_bytes()[0..N];
self.write_all(len).await?;
self.write_all(bytes).await?;
Ok(N + bytes.len())
}
#[inline]
/// Write inlined string with specific length width `N`.
async fn write_inlined_str<const N: usize>(&mut self, s: &str) -> std::io::Result<usize> {
self.write_inlined_bytes::<N>(s.as_bytes()).await
}
#[inline]
/// Write an inlinable object.
async fn write_inlinable<T: AsyncInlinable + Sync>(
&mut self,
value: &T,
) -> std::io::Result<usize>
where
Self: Sized,
{
// self.write_inlinable(value).await
T::write_inlined(value, self).await
}
}
impl<T> AsyncInlinableWrite for T where T: AsyncWrite + Send + Unpin {}