Borsh JS 和 Borsh Rust 序列化输出略有不同

Question

我正在尝试将 borsh 序列化数据从 JS 发送到 Rust 应用程序。但是，当在 javascript 和 rust 中序列化数据（以比较输出）时，我在 rust 序列化输出中得到了 4 个额外的字节。这是代码：

Borsh JS代码

// class
class Poll {
  id: string = '';
  question: string = '';
  options: string[] = [];
  votes: number[] = [];

  constructor(fields?: {
    id: string;
    question: string;
    options: string[];
    votes: number[];
  }) {
    if (fields) {
      this.id = fields.id;
      this.question = fields.question;
      this.options = fields.options;
      this.votes = fields.votes;
    }
  }
}

// Schema
const schema: Schema = new Map([
  [
    Poll,
    {
      kind: 'struct',
      fields: [
        ['id', 'string'],
        ['question', 'string'],
        ['options', ['string']],
        ['votes', ['u32', 1]],
      ],
    },
  ],
]);


// class object
const testPoll = new Poll({
  id: '1',
  question: 'What is your favorite color?',
  options: ['a', 'b', 'c'],
  votes: [100],
});

//object serialization
let serializedPoll: Uint8Array = new Uint8Array();
serializedPoll = serialize(schema, testPoll); // this succeeds

// output

[1, 0, 0, 0, 49, 28, 0, 0, 0, 87, 104, 97, 116, 32, 105, 115, 32, 121, 111, 117, 114, 32, 102, 97, 118, 111, 114, 105, 116, 101, 32, 99, 111, 108, 111, 114, 63, 3, 0, 0, 0, 1, 0, 0, 0, 97, 1, 0, 0, 0, 98, 1, 0, 0, 0, 99, 100, 0, 0, 0]

Borsh Rust 代码

#[derive(BorshDeserialize, BorshSerialize, Debug)]
pub struct Poll {
    pub id: String,
    pub question: String,
    pub options: Vec<String>,
    pub votes: Vec<u32>,
}

// poll object - with same values as that in JS code above
let p = Poll {
        id: "1".to_string(),
        question: "What is your favorite color?".to_string(),
        options: vec!["a".to_string(), "b".to_string(), "c".to_string()],
        votes: vec![100],
};

// serialization
let serialized_data = p.try_to_vec().unwrap(); // this succeeds

//output
[1, 0, 0, 0, 49, 28, 0, 0, 0, 87, 104, 97, 116, 32, 105, 115, 32, 121, 111, 117, 114, 32, 102, 97, 118, 111, 114, 105, 116, 101, 32, 99, 111, 108, 111, 114, 63, 3, 0, 0, 0, 1, 0, 0, 0, 97, 1, 0, 0, 0, 98, 1, 0, 0, 0, 99, 1, 0, 0, 0, 100, 0, 0, 0]

比较两者的输出

博尔什 JS
Borsh Rust

[1, 0, 0, 0, 49, 28, 0, 0, 0, 87, 104, 97, 116, 32, 105, 115, 32, 121, 111, 117, 114, 32, 102, 97, 118, 111, 114, 105, 116, 101, 32, 99, 111, 108, 111, 114, 63, 3, 0, 0, 0, 1, 0, 0, 0, 97, 1, 0, 0, 0, 98, 1, 0, 0, 0, 99, 100, 0, 0, 0]

[1, 0, 0, 0, 49, 28, 0, 0, 0, 87, 104, 97, 116, 32, 105, 115, 32, 121, 111, 117, 114, 32, 102, 97, 118, 111, 114, 105, 116, 101, 32, 99, 111, 108, 111, 114, 63, 3, 0, 0, 0, 1, 0, 0, 0, 97, 1, 0, 0, 0, 98, 1, 0, 0, 0, 99, 1, 0, 0, 0, 100, 0, 0, 0]

rust 序列化输出中有额外的 4 个字节 (1, 0, 0, 0)。我相信这是因为 Vec<u32> 用于 votes 字段（它适用于 u32）。但是我无法理解为什么会这样。

任何形式的 help/insights 都表示赞赏。

谢谢！

Answer 1

A Vec<u32> 必须对数据的长度进行编码，因为 Vec 表示可变大小。相反，您在 JS 中将模式设计为 ['u32', 1]，这是一个长度为 1 的数组，因此它不需要编码长度，因为它是固定大小。

要解决差异，请将架构设置为可变大小数组：['u32']。或者将 Rust 中的类型更改为 fixed-size 数组：votes: [u32; 1].

Borsh JS 和 Borsh Rust 序列化输出略有不同

Borsh JS and Borsh Rust slightly different serialized output

javascript

serialization

rust

deserialization