From 52d19c730bafe21cbd882553d282a5044d63de97 Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Thu, 5 Aug 2021 00:25:26 +0100
Subject: [PATCH] Start reworking SerializedMessage -> binary pipeline.
MIME-Version: 1.0
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Moved from `io::Write` to `bytes::BufMut`, etc.

TODO: Move from `io::Read` to `bytes::Buf` (SerializedMessage::<impl MessageValue>::from_buffer(impl Buf))

Fortune for rsh's current commit: Future small blessing − 末小吉
---
 Cargo.lock            | 12 +++++-
 Cargo.toml            |  1 +
 src/message.rs        | 10 ++++-
 src/message/binary.rs | 92 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 113 insertions(+), 2 deletions(-)
 create mode 100644 src/message/binary.rs

diff --git a/Cargo.lock b/Cargo.lock
index 90ff8a8..ec8287e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -77,6 +77,15 @@ version = "0.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0e4cec68f03f32e44924783795810fa50a7035d8c8ebe78580ad7e6c703fba38"
 
+[[package]]
+name = "bytes"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b700ce4376041dcd0a327fd0097c41095743c4c8af8887265942faf1100bd040"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.69"
@@ -780,6 +789,7 @@ dependencies = [
 name = "rsh"
 version = "0.1.0"
 dependencies = [
+ "bytes 1.0.1",
  "chacha20stream",
  "color-eyre",
  "cryptohelpers",
@@ -950,7 +960,7 @@ version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6703a273949a90131b290be1fe7b039d0fc884aa1935860dfcbe056f28cd8092"
 dependencies = [
- "bytes",
+ "bytes 0.5.6",
  "fnv",
  "futures-core",
  "iovec",
diff --git a/Cargo.toml b/Cargo.toml
index f8edb7a..d3a4e5d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bytes = { version = "1.0.1", features = ["serde"] }
 chacha20stream = { version = "1.0.3", features = ["async"] }
 color-eyre = "0.5.11"
 cryptohelpers = { version = "1.8.1" , features = ["serialise", "full"] }
diff --git a/src/message.rs b/src/message.rs
index 80a281e..4cf3f0c 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -236,6 +236,9 @@ impl<V: ?Sized + MessageValue> Message<V>
     }
 }
 
+mod binary;
+pub use binary::*;
+
 impl<V: ?Sized> SerializedMessage<V>
 {
     /// Get the message header
@@ -243,6 +246,9 @@ impl<V: ?Sized> SerializedMessage<V>
     {
 	MessageHeader(&self.header, PhantomData)
     }
+
+}
+/*
     /// Consume into an async writer
     pub async fn into_writer_async<W:AsyncWrite+Unpin>(self, mut writer: W) -> eyre::Result<usize>
     {
@@ -328,6 +334,8 @@ impl<V: ?Sized> SerializedMessage<V>
 	v
     }
 }
+ */
+/*
 impl<V: ?Sized + MessageValue> SerializedMessage<V>
 {
     /// Create from a reader.
@@ -420,6 +428,6 @@ impl<V: ?Sized + MessageValue> SerializedMessage<V>
 	Self::from_reader(&mut &bytes[..])
     }
 }
-
+*/
 #[cfg(test)]
 mod tests;
diff --git a/src/message/binary.rs b/src/message/binary.rs
new file mode 100644
index 0000000..7b5ea05
--- /dev/null
+++ b/src/message/binary.rs
@@ -0,0 +1,92 @@
+//! Creating binary from messages
+//!
+//! `SerializedMessage` to `Bytes`.
+use super::*;
+use bytes::{
+    Bytes,
+    BytesMut,
+    BufMut,
+    Buf,
+};
+
+impl<V: ?Sized> SerializedMessage<V>
+{
+    /// Write this message to a buffer
+    ///
+    /// # Panics
+    /// If `buffer` cannot hold enough bytes.
+    pub fn into_buffer(self, mut buffer: impl BufMut) -> eyre::Result<usize>
+    {
+	let mut w=0;
+	macro_rules! write {
+	    ($bytes:expr) => {
+		{
+		    let slice: &[u8] = ($bytes).as_ref();
+		    buffer.put_slice(slice);
+		    w+=slice.len();
+		}
+	    };
+	    (? $o:expr) => {
+		{
+		    match $o {
+			Some(opt) => {
+			    buffer.put_u8(1);
+			    write!(opt);
+			},
+			None => {buffer.put_u8(0);},
+		    }
+		    w+=1;
+		}
+	    };
+	    (: $ser:expr) => {
+		{		    
+		    let mut v = StackVec::new();
+		    serde_cbor::to_writer(&mut v, $ser)?;
+		    buffer.put_u64(v.len().try_into()?);
+		    write!(&v[..]);
+		}
+	    };
+	}
+	
+	write!(: &self.header);
+	buffer.put_u64(self.data.len().try_into()?);
+	write!(self.data);
+	write!(self.hash);
+	write!(? self.enc_key);
+	write!(? self.sig);
+	
+	Ok(w)
+    }
+    
+    /// Write this message to a new `Bytes`.
+    pub fn into_bytes(self) -> eyre::Result<Bytes>
+    {
+	let mut output = BytesMut::with_capacity(4096); //TODO: Find a better default capacity for this.
+	self.into_buffer(&mut output)?;
+	Ok(output.freeze())
+    }
+}
+
+impl<V: ?Sized + MessageValue> SerializedMessage<V>
+{
+    /// Create from a buffer of bytes.
+    ///
+    /// # Panics
+    /// If `bytes` does not contain enough data to read.
+    pub fn from_buffer(bytes: impl Buf) -> eyre::Result<Self>
+    {
+	todo!()
+    }
+
+    /// Create from a slice of bytes
+    #[inline] pub fn from_slice(bytes: impl AsRef<[u8]>) -> eyre::Result<Self>
+    {
+	Self::from_buffer(bytes.as_ref())
+    }
+
+    /// Create from a `Bytes` instance
+    #[inline(always)] pub fn from_bytes(bytes: Bytes) -> eyre::Result<Self>
+    {
+	Self::from_buffer(bytes)
+    }
+}