blob: 4223cace929ae1a3a66652835df58fcf86ca23cf (
plain)
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
|
use crate::{DeserializeErr, DeserializeResult};
use alloc::string::String;
pub fn take(amount: usize, data: &[u8]) -> DeserializeResult<&[u8]> {
if data.len() < amount {
Err(DeserializeErr::Eof)
} else {
Ok(data.split_at(amount).into())
}
}
pub fn hex(data: &[u8]) -> String {
let mut str = String::with_capacity(data.len() * 2);
for byte_ref in data {
let byte = *byte_ref;
str.push(hex_char_for(byte >> 4));
str.push(hex_char_for(byte & 0xF));
}
str
}
const ZERO_ASCII_CODE: u8 = 48;
const LOWER_A_ASCII_CODE: u8 = 97;
fn hex_char_for(half: u8) -> char {
if half > 0xF {
panic!("not defined for > 0xF (operates on half a byte)");
}
if half < 10 {
(half + ZERO_ASCII_CODE) as char
} else {
(half + (LOWER_A_ASCII_CODE - 10)) as char
}
}
pub fn parse_hex_char(data: u8) -> Option<u8> {
const UPPER_A_ASCII_CODE: u8 = 65;
const LOWER_F_ASCII_CODE: u8 = 102;
const UPPER_F_ASCII_CODE: u8 = 70;
const NINE_ASCII_CODE: u8 = 57;
if data >= LOWER_A_ASCII_CODE {
if data > LOWER_F_ASCII_CODE {
None
} else {
Some(10 + (data - LOWER_A_ASCII_CODE))
}
} else if data >= UPPER_A_ASCII_CODE {
if data > UPPER_F_ASCII_CODE {
None
} else {
Some(10 + (data - UPPER_A_ASCII_CODE))
}
} else if data >= ZERO_ASCII_CODE {
if data > NINE_ASCII_CODE {
None
} else {
Some(data - ZERO_ASCII_CODE)
}
} else {
None
}
}
|
