denyhosts/clamav/libclamav_rust/.cargo/vendor/lebe/README.md

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2023-01-14 18:28:39 +08:00
[![Rust Docs](https://docs.rs/lebe/badge.svg)](https://docs.rs/lebe)
[![Crate Crate](https://img.shields.io/crates/v/lebe.svg)](https://crates.io/crates/lebe)
![Lines of Code](https://tokei.rs/b1/github/johannesvollmer/lebe?category=code)
# 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 ![Lines of Code](https://tokei.rs/b1/github/BurntSushi/byteorder?category=code) 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'.