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use crate::{DeserializeErr, DeserializeResult, Deserialized};
use alloc::string::String;
pub fn read_one_byte(data: &[u8]) -> DeserializeResult<u8> {
match data.split_first() {
Some((byte, rest)) => Deserialized::ok(*byte, rest),
None => Err(DeserializeErr::Eof),
}
}
pub fn take(amount: usize) -> impl for<'b> Fn(&'b [u8]) -> DeserializeResult<'b, &'b [u8]> {
move |data| {
if data.len() < amount {
Err(DeserializeErr::Eof)
} else {
Ok(data.split_at(amount).into())
}
}
}
pub fn read_long(data: &[u8]) -> DeserializeResult<u64> {
Ok(take(8)(data)?.map(move |bytes| {
(bytes[0] as u64) << 56
| (bytes[1] as u64) << 48
| (bytes[2] as u64) << 40
| (bytes[3] as u64) << 32
| (bytes[4] as u64) << 24
| (bytes[5] as u64) << 16
| (bytes[6] as u64) << 8
| (bytes[7] as u64)
}))
}
pub fn write_long(v: u64) -> [u8; 8] {
[
(v >> 56) as u8,
(v >> 48) as u8,
(v >> 40) as u8,
(v >> 32) as u8,
(v >> 24) as u8,
(v >> 16) as u8,
(v >> 8) as u8,
v as u8,
]
}
pub fn read_int(data: &[u8]) -> DeserializeResult<u32> {
Ok(take(4)(data)?.map(move |bytes| {
(bytes[0] as u32) << 24
| (bytes[1] as u32) << 16
| (bytes[2] as u32) << 8
| (bytes[3] as u32)
}))
}
pub fn write_int(v: u32) -> [u8; 4] {
[(v >> 24) as u8, (v >> 16) as u8, (v >> 8) as u8, v as u8]
}
pub fn read_short(data: &[u8]) -> DeserializeResult<u16> {
Ok(take(2)(data)?.map(move |bytes| (bytes[0] as u16) << 8 | (bytes[1] as u16)))
}
pub fn write_short(v: u16) -> [u8; 2] {
[(v >> 8) as u8, v as u8]
}
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
}
}
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