🐎 Add ChunkExt::write_chunk_in_async, SealedEntryExt::write_in_async for reduce copy

lib/src/archive/write.rs

@@ -315,10 +315,7 @@ impl<W: AsyncWrite + Unpin> Archive<W> {
     /// This API is unstable.
     #[inline]
     pub async fn add_entry_async(&mut self, entry: impl Entry) -> io::Result<usize> {
-        let mut bytes = Vec::new();
-        entry.write_in(&mut bytes)?;
-        self.inner.write_all(&bytes).await?;
-        Ok(bytes.len())
+        entry.write_in_async(&mut self.inner).await
     }
 
     /// Write an end marker to finalize the archive.

lib/src/chunk.rs

@@ -44,6 +44,20 @@ pub(crate) trait ChunkExt: Chunk {
         Ok(self.bytes_len())
     }
 
+    #[cfg(feature = "unstable-async")]
+    #[inline]
+    async fn write_chunk_in_async<W: futures_io::AsyncWrite + std::marker::Unpin>(
+        &self,
+        writer: &mut W,
+    ) -> io::Result<usize> {
+        use futures_util::AsyncWriteExt;
+        writer.write_all(&self.length().to_be_bytes()).await?;
+        writer.write_all(&self.ty().0).await?;
+        writer.write_all(self.data()).await?;
+        writer.write_all(&self.crc().to_be_bytes()).await?;
+        Ok(self.bytes_len())
+    }
+
     /// Convert the provided `Chunk` instance into a `Vec<u8>`.
     ///
     /// # Returns