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