diff options
Diffstat (limited to 'src/byteorder.rs')
| -rw-r--r-- | src/byteorder.rs | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/src/byteorder.rs b/src/byteorder.rs new file mode 100644 index 0000000..298503d --- /dev/null +++ b/src/byteorder.rs @@ -0,0 +1,385 @@ +// Copyright (c) 2015 Andrew Gallant
+
+use std::io;
+use std::io::Result;
+use std::ptr::copy_nonoverlapping;
+
+#[derive(Copy, Clone)]
+pub struct LittleEndian;
+
+#[derive(Copy, Clone)]
+pub struct BigEndian;
+
+#[cfg(target_endian = "little")]
+pub type NativeEndian = LittleEndian;
+
+#[cfg(target_endian = "big")]
+pub type NativeEndian = BigEndian;
+
+macro_rules! read_num_bytes {
+ ($ty:ty, $size:expr, $src:expr, $which:ident) => {{
+ assert!($size == ::std::mem::size_of::<$ty>());
+ assert!($size <= $src.len());
+ let mut data: $ty = 0;
+ unsafe {
+ copy_nonoverlapping($src.as_ptr(), &mut data as *mut $ty as *mut u8, $size);
+ }
+ data.$which()
+ }};
+}
+
+macro_rules! write_num_bytes {
+ ($ty:ty, $size:expr, $n:expr, $dst:expr, $which:ident) => {{
+ assert!($size <= $dst.len());
+ unsafe {
+ // N.B. https://github.com/rust-lang/rust/issues/22776
+ let bytes = *(&$n.$which() as *const _ as *const [u8; $size]);
+ copy_nonoverlapping((&bytes).as_ptr(), $dst.as_mut_ptr(), $size);
+ }
+ }};
+}
+
+impl ByteOrder for LittleEndian {
+ #[inline]
+ fn read_u16(buf: &[u8]) -> u16 {
+ read_num_bytes!(u16, 2, buf, to_le)
+ }
+
+ #[inline]
+ fn read_u32(buf: &[u8]) -> u32 {
+ read_num_bytes!(u32, 4, buf, to_le)
+ }
+
+ #[inline]
+ fn read_u64(buf: &[u8]) -> u64 {
+ read_num_bytes!(u64, 8, buf, to_le)
+ }
+
+ #[inline]
+ fn write_u16(buf: &mut [u8], n: u16) {
+ write_num_bytes!(u16, 2, n, buf, to_le);
+ }
+
+ #[inline]
+ fn write_u32(buf: &mut [u8], n: u32) {
+ write_num_bytes!(u32, 4, n, buf, to_le);
+ }
+
+ #[inline]
+ fn write_u64(buf: &mut [u8], n: u64) {
+ write_num_bytes!(u64, 8, n, buf, to_le);
+ }
+
+ serde_if_integer128! {
+ #[inline]
+ fn write_u128(buf: &mut [u8], n: u128) {
+ write_num_bytes!(u128, 16, n, buf, to_le);
+ }
+
+ #[inline]
+ fn read_u128(buf: &[u8]) -> u128 {
+ read_num_bytes!(u128, 16, buf, to_le)
+ }
+ }
+}
+
+impl ByteOrder for BigEndian {
+ #[inline]
+ fn read_u16(buf: &[u8]) -> u16 {
+ read_num_bytes!(u16, 2, buf, to_be)
+ }
+
+ #[inline]
+ fn read_u32(buf: &[u8]) -> u32 {
+ read_num_bytes!(u32, 4, buf, to_be)
+ }
+
+ #[inline]
+ fn read_u64(buf: &[u8]) -> u64 {
+ read_num_bytes!(u64, 8, buf, to_be)
+ }
+
+ #[inline]
+ fn write_u16(buf: &mut [u8], n: u16) {
+ write_num_bytes!(u16, 2, n, buf, to_be);
+ }
+
+ #[inline]
+ fn write_u32(buf: &mut [u8], n: u32) {
+ write_num_bytes!(u32, 4, n, buf, to_be);
+ }
+
+ #[inline]
+ fn write_u64(buf: &mut [u8], n: u64) {
+ write_num_bytes!(u64, 8, n, buf, to_be);
+ }
+
+ serde_if_integer128! {
+ #[inline]
+ fn write_u128(buf: &mut [u8], n: u128) {
+ write_num_bytes!(u128, 16, n, buf, to_be);
+ }
+
+ #[inline]
+ fn read_u128(buf: &[u8]) -> u128 {
+ read_num_bytes!(u128, 16, buf, to_be)
+ }
+ }
+}
+
+pub trait ByteOrder: Clone + Copy {
+ fn read_u16(buf: &[u8]) -> u16;
+
+ fn read_u32(buf: &[u8]) -> u32;
+
+ fn read_u64(buf: &[u8]) -> u64;
+
+ fn write_u16(buf: &mut [u8], n: u16);
+
+ fn write_u32(buf: &mut [u8], n: u32);
+
+ fn write_u64(buf: &mut [u8], n: u64);
+
+ #[inline]
+ fn read_i16(buf: &[u8]) -> i16 {
+ Self::read_u16(buf) as i16
+ }
+
+ #[inline]
+ fn read_i32(buf: &[u8]) -> i32 {
+ Self::read_u32(buf) as i32
+ }
+
+ #[inline]
+ fn read_i64(buf: &[u8]) -> i64 {
+ Self::read_u64(buf) as i64
+ }
+
+ #[inline]
+ fn read_f32(buf: &[u8]) -> f32 {
+ unsafe { *(&Self::read_u32(buf) as *const u32 as *const f32) }
+ }
+
+ #[inline]
+ fn read_f64(buf: &[u8]) -> f64 {
+ unsafe { *(&Self::read_u64(buf) as *const u64 as *const f64) }
+ }
+
+ #[inline]
+ fn write_i16(buf: &mut [u8], n: i16) {
+ Self::write_u16(buf, n as u16)
+ }
+
+ #[inline]
+ fn write_i32(buf: &mut [u8], n: i32) {
+ Self::write_u32(buf, n as u32)
+ }
+
+ #[inline]
+ fn write_i64(buf: &mut [u8], n: i64) {
+ Self::write_u64(buf, n as u64)
+ }
+
+ #[inline]
+ fn write_f32(buf: &mut [u8], n: f32) {
+ let n = unsafe { *(&n as *const f32 as *const u32) };
+ Self::write_u32(buf, n)
+ }
+
+ #[inline]
+ fn write_f64(buf: &mut [u8], n: f64) {
+ let n = unsafe { *(&n as *const f64 as *const u64) };
+ Self::write_u64(buf, n)
+ }
+
+ serde_if_integer128! {
+ fn read_u128(buf: &[u8]) -> u128;
+ fn write_u128(buf: &mut [u8], n: u128);
+
+ #[inline]
+ fn read_i128(buf: &[u8]) -> i128 {
+ Self::read_u128(buf) as i128
+ }
+
+ #[inline]
+ fn write_i128(buf: &mut [u8], n: i128) {
+ Self::write_u128(buf, n as u128)
+ }
+ }
+}
+
+pub trait ReadBytesExt: io::Read {
+ #[inline]
+ fn read_u8(&mut self) -> Result<u8> {
+ let mut buf = [0; 1];
+ try!(self.read_exact(&mut buf));
+ Ok(buf[0])
+ }
+
+ #[inline]
+ fn read_i8(&mut self) -> Result<i8> {
+ let mut buf = [0; 1];
+ try!(self.read_exact(&mut buf));
+ Ok(buf[0] as i8)
+ }
+
+ #[inline]
+ fn read_u16<T: ByteOrder>(&mut self) -> Result<u16> {
+ let mut buf = [0; 2];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_u16(&buf))
+ }
+
+ #[inline]
+ fn read_i16<T: ByteOrder>(&mut self) -> Result<i16> {
+ let mut buf = [0; 2];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_i16(&buf))
+ }
+
+ #[inline]
+ fn read_u32<T: ByteOrder>(&mut self) -> Result<u32> {
+ let mut buf = [0; 4];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_u32(&buf))
+ }
+
+ #[inline]
+ fn read_i32<T: ByteOrder>(&mut self) -> Result<i32> {
+ let mut buf = [0; 4];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_i32(&buf))
+ }
+
+ #[inline]
+ fn read_u64<T: ByteOrder>(&mut self) -> Result<u64> {
+ let mut buf = [0; 8];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_u64(&buf))
+ }
+
+ #[inline]
+ fn read_i64<T: ByteOrder>(&mut self) -> Result<i64> {
+ let mut buf = [0; 8];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_i64(&buf))
+ }
+
+ #[inline]
+ fn read_f32<T: ByteOrder>(&mut self) -> Result<f32> {
+ let mut buf = [0; 4];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_f32(&buf))
+ }
+
+ #[inline]
+ fn read_f64<T: ByteOrder>(&mut self) -> Result<f64> {
+ let mut buf = [0; 8];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_f64(&buf))
+ }
+
+ serde_if_integer128! {
+ #[inline]
+ fn read_u128<T: ByteOrder>(&mut self) -> Result<u128> {
+ let mut buf = [0; 16];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_u128(&buf))
+ }
+
+ #[inline]
+ fn read_i128<T: ByteOrder>(&mut self) -> Result<i128> {
+ let mut buf = [0; 16];
+ try!(self.read_exact(&mut buf));
+ Ok(T::read_i128(&buf))
+ }
+ }
+}
+
+impl<R: io::Read + ?Sized> ReadBytesExt for R {}
+
+pub trait WriteBytesExt: io::Write {
+ #[inline]
+ fn write_u8(&mut self, n: u8) -> Result<()> {
+ self.write_all(&[n])
+ }
+
+ #[inline]
+ fn write_i8(&mut self, n: i8) -> Result<()> {
+ self.write_all(&[n as u8])
+ }
+
+ #[inline]
+ fn write_u16<T: ByteOrder>(&mut self, n: u16) -> Result<()> {
+ let mut buf = [0; 2];
+ T::write_u16(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_i16<T: ByteOrder>(&mut self, n: i16) -> Result<()> {
+ let mut buf = [0; 2];
+ T::write_i16(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_u32<T: ByteOrder>(&mut self, n: u32) -> Result<()> {
+ let mut buf = [0; 4];
+ T::write_u32(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_i32<T: ByteOrder>(&mut self, n: i32) -> Result<()> {
+ let mut buf = [0; 4];
+ T::write_i32(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_u64<T: ByteOrder>(&mut self, n: u64) -> Result<()> {
+ let mut buf = [0; 8];
+ T::write_u64(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_i64<T: ByteOrder>(&mut self, n: i64) -> Result<()> {
+ let mut buf = [0; 8];
+ T::write_i64(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_f32<T: ByteOrder>(&mut self, n: f32) -> Result<()> {
+ let mut buf = [0; 4];
+ T::write_f32(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_f64<T: ByteOrder>(&mut self, n: f64) -> Result<()> {
+ let mut buf = [0; 8];
+ T::write_f64(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ serde_if_integer128! {
+ #[inline]
+ fn write_u128<T: ByteOrder>(&mut self, n: u128) -> Result<()> {
+ let mut buf = [0; 16];
+ T::write_u128(&mut buf, n);
+ self.write_all(&buf)
+ }
+
+ #[inline]
+ fn write_i128<T: ByteOrder>(&mut self, n: i128) -> Result<()> {
+ let mut buf = [0; 16];
+ T::write_i128(&mut buf, n);
+ self.write_all(&buf)
+ }
+ }
+}
+
+impl<W: io::Write + ?Sized> WriteBytesExt for W {}
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