serde_rustler

serde_rustler 为 Serde 序列化和反序列化 Rustler 类型提供了序列化器和反序列化器，因此您可以在NIFs中轻松地将本地Rust类型直接序列化和反序列化为本地Elixir术语。

安装

从 Crates.io 安装

[dependencies]
serde_rustler = "0.0.3"

快速入门

#[macro_use] extern crate rustler;

use serde::{Serialize, Deserialize}
use serde_rustler::{from_term, to_term};

rustler_export_nifs! {
    "Elixir.SerdeRustlerTests",
    [("nif", 1, nif)],
    None
}

#[derive(Serialize, Deserialize)]
struct Animal = { ... };

fn nif<'a>(env: Env<'a>, args: &[Term<'a>]) -> NifResult<Term<'a>> {
    // Deserialize term into a native Rust type.
    let animal: Animal = from_term(args[0])?;

    // Serialize a type into an Elixir term.
    to_term(env, animal).map_err(|err| err.into())
}

使用方法

以下是一个更全面的示例，说明如何在rust NIF中使用 serde_rustler...

#[macro_use]
extern crate rustler;

use rustler::{Env, error::Error as NifError, NifResult, Term};
use serde::{Serialize, Deserialize};
use serde_rustler::{from_term, to_term};

rustler_export_nifs! {
    "Elixir.SerdeNif",
    [("readme", 1, readme)],
    None
}

// NOTE: to serialize to the correct Elixir record, you MUST tell serde to
// rename the variants to the full Elixir record module atom.
#[derive(Debug, Serialize, Deserialize)]
enum AnimalType {
    #[serde(rename = "Elixir.SerdeNif.AnimalType.Cat")]
    Cat(String),
    #[serde(rename = "Elixir.SerdeNif.AnimalType.Dog")]
    Dog(String),
}

// NOTE: to serialize to an actual Elixir struct (rather than a just map with
// a :__struct__ key), you MUST tell serde to rename the struct to the full
// Elixir struct module atom.
#[derive(Debug, Serialize, Deserialize)]
#[serde(rename = "Elixir.SerdeNif.Animal")]
struct Animal {
    #[serde(rename = "type")]
    _type: AnimalType,
    name: String,
    age: u8,
    owner: Option<String>,
}

fn readme<'a>(env: Env<'a>, args: &[Term<'a>]) -> NifResult<Term<'a>> {
    let animal: Animal = from_term(args[0])?;
    println!("serialized animal: {:?}", animal);
    to_term(env, animal).map_err(|err| err.into())
}

...以及如何构建相应的Elixir类型（为了简洁，代码结构、import、alias和require已简化或省略）

defmodule SerdeNif do
  use Rustler, otp_app: :serde_nif

  def readme(_term), do: :erlang.nif_error(:nif_not_loaded)

  defmodule Animal do
    @type t :: %Animal{
      type: Cat.t() | Dog.t(),
      name: bitstring,
      age: pos_integer,
      owner: nil | bitstring
    }
    defstruct type: Cat.record(), name: "", age: 0, owner: nil

    @doc """
    Deserializes term as a Rust `Animal` struct, then serializes it back into
    an Elixir `Animal` struct. Should return true.
    """
    def test() do
      animal = %Animal{
        type: Animal.Cat.record(),
        name: "Garfield",
        age: 41,
      }

      SerdeNif.readme(animal) == animal
    end
  end

  defmodule AnimalType.Cat do
    require Record
    @type t {__MODULE__, String.t()}
    Record.defrecord(:record, __MODULE__, breed: "tabby")
  end

  defmodule AnimalType.Dog do
    # omitted
  end
end

转换表

1: API 正在决定 / 实现。

2: 当将未知输入序列化为项时，不会创建原子，而是用 Elixir 字节数组代替。因此“记录”将是元组（{bitstring, ...}），“结构体”将是包含 %{:__struct__ => bitstring} 的映射。不幸的后果是 deserialize_any 将缺少在无类型提示的情况下反序列化许多项所需的信息，例如 structs，enums 和 enum variants，以及 tuples。对于如何最好地解决这个问题，欢迎在此处提供反馈 here）。

cd serde_rustler_tests
MIX_ENV=bench mix run test/benchmarks.exs

• 完成有关字符、字符列表、io列表、映射键的行为
• 还在适应 Rust，可能需要改进 API 的错误处理和用户界面
• 支持 i128 和 u128
• 更广泛的测试（例如可能添加 smoke 测试和基于属性的测试）
• 调查 decode_json（序列化器？）性能下降