From 8db525dab49593d92689cdda7878117c9d475170 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Sat, 5 Sep 2020 10:06:58 -0400
Subject: [PATCH] tor-bytes: Add initial support for the bytes crate

---
 tor-bytes/Cargo.toml    | 1 +
 tor-bytes/src/impls.rs  | 7 +++++++
 tor-bytes/src/reader.rs | 9 +++++++++
 3 files changed, 17 insertions(+)

diff --git a/tor-bytes/Cargo.toml b/tor-bytes/Cargo.toml
index eb7b39e4d..409e3bc7a 100644
--- a/tor-bytes/Cargo.toml
+++ b/tor-bytes/Cargo.toml
@@ -14,6 +14,7 @@ generic-array = "0.14.4"
 crypto-mac = "0.9.1"
 thiserror = "1.0.20"
 signature = "1.2.2"
+bytes = "*"
 
 [dev-dependencies]
 hex-literal = "0.3.1"
diff --git a/tor-bytes/src/impls.rs b/tor-bytes/src/impls.rs
index 40463d4b3..1271982d0 100644
--- a/tor-bytes/src/impls.rs
+++ b/tor-bytes/src/impls.rs
@@ -5,6 +5,7 @@
 //! this is where I'm putting them.
 
 use super::*;
+use bytes;
 use generic_array::GenericArray;
 
 // ----------------------------------------------------------------------
@@ -25,6 +26,12 @@ impl Writer for Vec<u8> {
     }
 }
 
+impl Writer for bytes::BytesMut {
+    fn write_all(&mut self, bytes: &[u8]) {
+        self.extend_from_slice(bytes);
+    }
+}
+
 // ----------------------------------------------------------------------
 
 impl<'a> Writeable for [u8] {
diff --git a/tor-bytes/src/reader.rs b/tor-bytes/src/reader.rs
index 8ef96a821..9f6c298cd 100644
--- a/tor-bytes/src/reader.rs
+++ b/tor-bytes/src/reader.rs
@@ -1,5 +1,6 @@
 use crate::{Error, Readable, Result};
 use arrayref::array_ref;
+use bytes;
 
 /// A type for reading messages from a slice of bytes.
 ///
@@ -54,6 +55,14 @@ impl<'a> Reader<'a> {
     pub fn from_slice(slice: &'a [u8]) -> Self {
         Reader { b: slice, off: 0 }
     }
+    /// Construct a new Reader from a 'Bytes' object.
+    pub fn from_bytes(b: &'a bytes::Bytes) -> Self {
+        Self::from_slice(b.as_ref())
+    }
+    /// Construct a new Reader from a 'BytesMut' object
+    pub fn from_bytes_mut(b: &'a bytes::BytesMut) -> Self {
+        Self::from_slice(b.as_ref())
+    }
     /// Return the total length of the slice in this reader, including
     /// consumed bytes and remaining bytes.
     pub fn total_len(&self) -> usize {