Lib.rs

文档

此库用于将结构化数据以二进制格式进行序列化和反序列化。

示例

[dependencies]
databuf = "0.5"

use databuf::{*, config::num::LE};

#[derive(Encode, Decode)]
struct Car<'a> {
    year: u16,
    is_new: bool,
    name: &'a str,
}

#[derive(Encode, Decode)]
struct Company<'a> { name: String, cars: Vec<Car<'a>> }

let old = Company {
    name: "Tesla".into(),
    cars: vec![
        Car { name: "Model S", year: 2018, is_new: true },
        Car { name: "Model X", year: 2019, is_new: false },
    ],
};
let bytes = old.to_bytes::<LE>();
let new = Company::from_bytes::<LE>(&bytes).unwrap();

Vec, String, &[T], &str 等等，编码时先编码长度值，然后编码每个条目。

默认情况下，集合的长度使用 BEU30 表示。

use databuf::{*, config::num::LE};

#[derive(Encode, Decode)]
struct Msg<'a> {
    id: u16,
    data: &'a str,
}
let bytes = [42, 0, 13, 72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33];
//           ^^^^^  ^^  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
//            Id    Len                         Data

let msg = Msg::from_bytes::<LE>(&bytes).unwrap();
assert_eq!(msg.id, 42);
assert_eq!(msg.data, "Hello, World!"); // Here, data is referenced.

• 示例：将数据编码到指定大小的缓冲区中。

use databuf::{*, config::{num, len}};
/// Use big endian byte order + Encode `msg` length with `databuf::var_int::BEU15` 
const CONFIG: u16 = num::BE | len::BEU15;

#[derive(Encode, Decode)]
struct Date {
    year: u16,
    month: u8,
    day: u8,
}

#[derive(Encode, Decode)]
struct Record<T> {
    id: T,
    date: Date,
    msg: String,
}

let record = Record { id: 42_u32, date: Date { year: 2018, month: 3, day: 7 }, msg: "Hello!".into() };

let mut buf = [0; 20];
let remaining = &mut buf.as_mut_slice();
record.encode::<CONFIG>(remaining).unwrap();

let amt = 20 - remaining.len();
assert_eq!(amt, 15); // 15 bytes written to `buf`