91 lines
2.8 KiB
Markdown
91 lines
2.8 KiB
Markdown
[](https://docs.rs/lebe)
|
|
[](https://crates.io/crates/lebe)
|
|
|
|
|
|
|
|
# LEBE
|
|
Tiny, dead simple, high performance endianness conversions with a generic API.
|
|
This crate purposefully does not have a different method, like `write_u16(my_value)`, for each primitive type. Instead, this uses generic type inference: `write(my_u16)`.
|
|
|
|
# Purpose
|
|
This crate has exactly two purposes:
|
|
1. Simple conversion between slices of primitives and byte arrays without unsafe code
|
|
2. Simple and fast conversion from one endianness to the other one
|
|
|
|
The [byteorder crate](https://github.com/BurntSushi/byteorder) uses  for this.
|
|
|
|
This simplifies reading and writing binary data to files or network streams.
|
|
|
|
|
|
# Usage
|
|
|
|
Write values.
|
|
```rust
|
|
use lebe::io::WriteEndian;
|
|
use std::io::Write;
|
|
|
|
fn main(){
|
|
let mut output_bytes: Vec<u8> = Vec::new();
|
|
|
|
let numbers: &[i32] = &[ 32, 102, 420, 594 ];
|
|
output_bytes.write_as_little_endian(numbers.len()).unwrap();
|
|
output_bytes.write_as_little_endian(numbers).unwrap();
|
|
}
|
|
```
|
|
|
|
Read numbers.
|
|
```rust
|
|
use lebe::io::ReadEndian;
|
|
use std::io::Read;
|
|
|
|
fn main(){
|
|
let mut input_bytes: &[u8] = &[ 3, 244 ];
|
|
let number: u16 = input_bytes.read_from_little_endian().unwrap();
|
|
}
|
|
```
|
|
|
|
Read slices.
|
|
```rust
|
|
use lebe::io::ReadEndian;
|
|
use std::io::Read;
|
|
|
|
fn main(){
|
|
let mut input_bytes: &[u8] = &[ 0, 2, 0, 3, 244, 1, 0, 3, 244, 1 ];
|
|
|
|
let len: u16 = input_bytes.read_from_little_endian().unwrap();
|
|
let mut numbers = vec![ 0.0; len as usize ];
|
|
|
|
input_bytes.read_from_little_endian_into(numbers.as_mut_slice()).unwrap();
|
|
}
|
|
```
|
|
|
|
Convert slices in-place.
|
|
```rust
|
|
use lebe::Endian;
|
|
|
|
fn main(){
|
|
let mut numbers: &[i32] = &[ 32, 102, 420, 594 ];
|
|
numbers.convert_current_to_little_endian();
|
|
}
|
|
```
|
|
|
|
|
|
# Why not use [byteorder](https://crates.io/crates/byteorder)?
|
|
This crate supports batch-writing slices with native speed
|
|
where the os has the matching endianness. Writing slices in `byteorder`
|
|
must be done manually, and may be slower than expected.
|
|
This crate does provide u8 and i8 slice operations for completeness.
|
|
Also, the API of this crate looks simpler.
|
|
|
|
# Why not use [endianness](https://crates.io/crates/endianness)?
|
|
This crate has no runtime costs, just as `byteorder`.
|
|
|
|
# Why not use this crate?
|
|
The other crates probably have better documentation.
|
|
|
|
|
|
# Fun Facts
|
|
LEBE is made up from 'le' for little endian and 'be' for big endian.
|
|
If you say that word using english pronounciation,
|
|
a german might think you said the german word for 'love'.
|