CapWriter

A fast serializer for Vec/slice with a lightweight cap" header.

Usage

Save & Load

use capwriter::{Save, Load};

let original: Vec<i32> = vec![1, 2, 3, 4, 5];

// (1) Save
let mut buf = Vec::new();
original.save_as_ne(&mut buf).unwrap();
assert_eq!(original.encoded_len(), buf.len()); // size can be estimated

// (2) Load
let decoded = Vec::<i32>::load_as_ne(&mut &buf[..]).unwrap();
assert_eq!(original, decoded);

AsyncSave & AsyncLoad (on async-tokio feature)

use capwriter::{AsyncSave, AsyncLoad};
use std::pin::Pin;

let vec_to_save: Vec<i32> = vec![1, 2, 3, 4, 5];

// (1) Save
let mut buffer = Vec::new();
vec_to_save.save_as_ne(Pin::new(&mut buffer)).await.unwrap();

// (2) Load
let vec_loaded = Vec::<i32>::load_as_ne(Pin::new(&mut &buffer[..])).await.unwrap();

assert_eq!(vec_to_save, vec_loaded);

Supported types

• trait Save can be used in:
  • Vec<T>, &[T], [T; usize]
• trait Load can be used in:
  • Vec<T>, [T; usize]
• For the T: (), u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64, Option<T>, PhantomData<T>, tuples up to 12 elements
  • impl the trait Pod (Plain Old Data) in bytemuck(https://crates.io/crates/bytemuck) crate.

Bench

• Run bench with cargo bench

• For Vec<usize> length of 10,000,000 (for v0.2.0)

  	capwriter	with serialized data
  save	21.483 ms	25.506 ms
  load	12.001 ms	77.664 ms

Notes

Cap size

Since v0.4, the header uses u64 instead of usize so that data are portable across 32- and 64-bit platforms.

Safety

capwriter does no runtime type checking. Supplying a buffer whose contents do not match the expected T results in undefined behaviour (panic, corrupted data, or excessive allocation). Ensure that the producer and consumer agree on the exact element type.