Serialise singleton, write singleton both working (barebones)

Fortune for transfer's current commit: Blessing − 吉

src/enc.rs

@@ -1,5 +1,6 @@
 //! Encodings
 use super::*;
+use ext::*;
 use std::{fmt, error};
 use bytes::{
     Buf,
@@ -65,17 +66,19 @@ impl Default for SerialFormat
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash, Copy)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Copy, Default)]
 pub struct SendOpt
 {
     pub comp: Option<CompressionKind>,
     pub encrypt: Option<EncryptionKind>,
     pub format: SerialFormat,
 }
+ref_self!(SendOpt);
 
+/// Default buffer size for encryption transform stream copying.
 pub const DEFAULT_BUFSIZE: usize = 4096;
 
-pub async fn cha_copy<F, T, const BUFSIZE: usize, const DECRYPT: bool>(from: &mut F, to: &mut T, key: &key::Key, iv: &key::IV) -> io::Result<(usize, usize)>
+async fn cha_copy<F, T, const BUFSIZE: usize, const DECRYPT: bool>(from: &mut F, to: &mut T, key: &key::Key, iv: &key::IV) -> io::Result<(usize, usize)>
 where F: AsyncRead + Unpin + ?Sized,
       T: AsyncWrite + Unpin + ?Sized
 {
@@ -101,8 +104,10 @@ where F: AsyncRead + Unpin + ?Sized,
     Ok((written, read))
 }
 
-async fn ser_singleton_inner<T: Serialize>(value: &T, how: &SendOpt) -> Result<Vec<u8>, SendErrorKind>
+async fn ser_singleton_inner<T: Serialize, V: AsyncWrite + Unpin, F>(to: F, value: &T, how: impl AsRef<SendOpt>) -> Result<(V, usize), SendErrorKind>
+where F: FnOnce(&Vec<u8>) -> V
 {
+    let how = how.as_ref();
     let ser = match how.format {
 	SerialFormat::Text => serde_json::to_vec(value)?,
 	SerialFormat::Binary => serde_cbor::to_vec(value)?,
@@ -122,17 +127,17 @@ async fn ser_singleton_inner<T: Serialize>(value: &T, how: &SendOpt) -> Result<V
 	    b = &ser[..];
 	    &mut b
 	};
-    let mut ser = Vec::with_capacity(ser.len());
-    if let Some(enc) = &how.encrypt {
+    let mut ser = to(&ser);
+    let w= if let Some(enc) = &how.encrypt {
 	match enc {
 	    EncryptionKind::Chacha20((k, iv)) => {
-		self::cha_copy::<_, _, 4096, false>(reader, &mut ser, k, iv).await?;
+		self::cha_copy::<_, _, DEFAULT_BUFSIZE, false>(reader, &mut ser, k, iv).await?.0
 	    },
 	}
     } else {
-	tokio::io::copy(reader, &mut ser).await?;
-    }
-    Ok(ser)
+	tokio::io::copy(reader, &mut ser).await? as usize
+    };
+    Ok((ser, w))
     // inner(value, how).map(|res| res.map_err(|k| SendError(Box::new((k, how.clone())))))
 }
 
@@ -140,15 +145,19 @@ async fn ser_singleton_inner<T: Serialize>(value: &T, how: &SendOpt) -> Result<V
 {
     use futures::prelude::*;
     // hack to avoid having to enable `try{}` feature :/
-    ser_singleton_inner(value, how).map_err(|k| SendError(Box::new((k, how.clone()))))
+    ser_singleton_inner(|c| Vec::with_capacity(c.len()), value, how)
+        .map_ok(|(v, _)| v)
+	.map_err(|k| SendError(Box::new((k, how.clone()))))
 }
 
-pub async fn write_singleton<T: Serialize, S: ?Sized + AsyncWrite + Unpin>(to: &mut S, value: &T, how: &SendOpt) -> Result<usize, SendError>
+/// Serialise a single object to a stream with the method described by `how`.
+#[inline] pub async fn write_singleton<T: Serialize, S: ?Sized + AsyncWrite + Unpin>(to: &mut S, value: &T, how: &SendOpt) -> Result<usize, SendError>
 {
-    Ok(0)
+    ser_singleton_inner(|_| to, value, &how).await
+	.map_err(|k| SendError(Box::new((k, how.to_owned()))))
+        .map(|(_, n)| n)
 }
 
-
 #[derive(Debug)]
 pub enum SendErrorKind
 {
@@ -163,6 +172,7 @@ pub enum SendErrorKind
     IO(io::Error),
 }
 
+/// An error when sending / serialising an object.
 #[derive(Debug)]
 pub struct SendError(Box<(SendErrorKind, SendOpt)>);
 

src/ext.rs

@@ -13,6 +13,7 @@ pub use std::{
     marker::{
 	Send, Sync, Unpin,
     },
+    borrow::{ Borrow, BorrowMut },
     convert::{
 	Infallible,
 	TryFrom,
@@ -27,6 +28,23 @@ pub use tokio::{
     task::JoinHandle,
 };
 
+/// Make this type act as a reference to itself.
+///
+/// Implements `AsRef<T>` for type `T`.
+#[macro_export] macro_rules! ref_self {
+    ($type:ty) => {
+	impl AsRef<$type> for $type
+	{
+	    #[inline] fn as_ref(&self) -> &$type
+	    {
+		self
+	    }
+	}
+
+    }
+}
+
+
 #[derive(Debug, Clone)]
 pub struct HexStringIter<I>(I, [u8; 2]);
 

src/send/handshake.rs

@@ -13,10 +13,11 @@ pub struct Request
     
 }
 
-
+/*
 pub async fn read_req<T>(mut from: T, key: ) -> eyre::Result<Request>
 where T: AsyncRead + Unpin
 {
     todo!("how do we handle encryption of the request data? eh... boring")
 }
 
+*/