1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
use std::io::prelude::*;
#[derive(Clone, Debug, PartialEq, PartialOrd, Default)]
pub struct Settings {
pub byte_order: ByteOrder,
}
#[derive(Copy, Clone, Debug, Eq, PartialOrd, Ord, Hash)]
pub enum ByteOrder {
LittleEndian,
BigEndian,
NativeEndian,
}
#[cfg(target_endian = "little")]
const NATIVE_BYTE_ORDER: ByteOrder = ByteOrder::LittleEndian;
#[cfg(target_endian = "big")]
const NATIVE_BYTE_ORDER: ByteOrder = ByteOrder::BigEndian;
impl ByteOrder {
fn realize(self) -> Self {
match self {
ByteOrder::NativeEndian => NATIVE_BYTE_ORDER,
b => b,
}
}
}
impl Default for ByteOrder {
fn default() -> Self {
ByteOrder::BigEndian
}
}
impl ::std::cmp::PartialEq for ByteOrder {
fn eq(&self, other: &Self) -> bool {
use ByteOrder::*;
match (self.realize(), other.realize()) {
(LittleEndian, LittleEndian) => true,
(BigEndian, BigEndian) => true,
_ => false,
}
}
}
macro_rules! impl_byte_order_helpers {
( $( $ty:ty => [ $read_name:ident : $write_name:ident ] )* ) => {
impl ByteOrder {
$(
pub fn $read_name(&self, read: &mut dyn Read) -> Result<$ty, crate::Error> {
use byteorder as bo;
Ok(match *self {
ByteOrder::LittleEndian => bo::ReadBytesExt::$read_name::<bo::LittleEndian>(read),
ByteOrder::BigEndian => bo::ReadBytesExt::$read_name::<bo::BigEndian>(read),
ByteOrder::NativeEndian => bo::ReadBytesExt::$read_name::<bo::NativeEndian>(read),
}?)
}
pub fn $write_name(&self, value: $ty,
write: &mut dyn Write) -> Result<(), crate::Error> {
use byteorder as bo;
Ok(match *self {
ByteOrder::LittleEndian => bo::WriteBytesExt::$write_name::<bo::LittleEndian>(write, value),
ByteOrder::BigEndian => bo::WriteBytesExt::$write_name::<bo::BigEndian>(write, value),
ByteOrder::NativeEndian => bo::WriteBytesExt::$write_name::<bo::NativeEndian>(write, value),
}?)
}
)*
}
};
}
impl_byte_order_helpers!(
u16 => [read_u16 : write_u16]
i16 => [read_i16 : write_i16]
u32 => [read_u32 : write_u32]
i32 => [read_i32 : write_i32]
u64 => [read_u64 : write_u64]
i64 => [read_i64 : write_i64]
f32 => [read_f32 : write_f32]
f64 => [read_f64 : write_f64]
);