Specialize u8 writes

Author: kornelski

rmp/src/encode/mod.rs

@@ -13,7 +13,7 @@ pub use self::bin::{write_bin, write_bin_len};
 pub use self::dec::{write_f32, write_f64};
 pub use self::sint::{write_i16, write_i32, write_i64, write_i8, write_nfix, write_sint};
 pub use self::str::{write_str, write_str_len};
-pub use self::uint::{write_pfix, write_u16, write_u32, write_u64, write_u8, write_uint};
+pub use self::uint::{write_pfix, write_u16, write_u32, write_u64, write_u8, write_uint, write_uint8};
 
 #[cfg(feature = "std")]
 use std::error;

rmp/src/encode/uint.rs

@@ -121,6 +121,20 @@ pub fn write_u64<W: RmpWrite>(wr: &mut W, val: u64) -> Result<(), ValueWriteErro
     Ok(())
 }
 
+/// Encodes and attempts to write an `u8` value into the given write using the most efficient
+/// representation, returning the marker used.
+///
+/// See [`write_uint`] for more info.
+pub fn write_uint8<W: RmpWrite>(wr: &mut W, val: u8) -> Result<Marker, ValueWriteError<W::Error>> {
+    if val < 128 {
+        write_pfix(wr, val as u8)
+            .and(Ok(Marker::FixPos(val as u8)))
+            .map_err(ValueWriteError::InvalidMarkerWrite)
+    } else {
+        write_u8(wr, val as u8).and(Ok(Marker::U8))
+    }
+}
+
 /// Encodes and attempts to write an `u64` value into the given write using the most efficient
 /// representation, returning the marker used.
 ///
@@ -135,12 +149,8 @@ pub fn write_u64<W: RmpWrite>(wr: &mut W, val: u64) -> Result<(), ValueWriteErro
 /// This function will return `ValueWriteError` on any I/O error occurred while writing either the
 /// marker or the data.
 pub fn write_uint<W: RmpWrite>(wr: &mut W, val: u64) -> Result<Marker, ValueWriteError<W::Error>> {
-    if val < 128 {
-        write_pfix(wr, val as u8)
-            .and(Ok(Marker::FixPos(val as u8)))
-            .map_err(ValueWriteError::InvalidMarkerWrite)
-    } else if val < 256 {
-        write_u8(wr, val as u8).and(Ok(Marker::U8))
+    if val < 256 {
+        write_uint8(wr, val as u8)
     } else if val < 65536 {
         write_u16(wr, val as u16).and(Ok(Marker::U16))
     } else if val < 4294967296 {