https://github.com/near/borsh-rs

Rust implementation of Binary Object Representation Serializer for Hashing
https://github.com/near/borsh-rs

binary-serialization borsh rust serialization

Last synced: 2 days ago
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Rust implementation of Binary Object Representation Serializer for Hashing

• Host: GitHub
• URL: https://github.com/near/borsh-rs
• Owner: near
• License: apache-2.0
• Created: 2020-11-25T09:11:11.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2024-10-28T19:34:31.000Z (11 days ago)
• Last Synced: 2024-10-29T12:15:04.748Z (10 days ago)
• Topics: binary-serialization, borsh, rust, serialization
• Language: Rust
• Homepage: https://borsh.io/
• Size: 67.5 MB
• Stars: 320
• Watchers: 11
• Forks: 67
• Open Issues: 24
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE-APACHE
  • Codeowners: CODEOWNERS

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README

        
# Borsh in Rust   [![Latest Version]][crates.io] [![borsh: rustc 1.67+]][Rust 1.67] [![License Apache-2.0 badge]][License Apache-2.0] [![License MIT badge]][License MIT]

[Borsh]: https://borsh.io

[Latest Version]: https://img.shields.io/crates/v/borsh.svg

[crates.io]: https://crates.io/crates/borsh

[borsh: rustc 1.67+]: https://img.shields.io/badge/rustc-1.67+-lightgray.svg

[Rust 1.67]: https://blog.rust-lang.org/2023/01/26/Rust-1.67.0.html

[License Apache-2.0 badge]: https://img.shields.io/badge/license-Apache2.0-blue.svg

[License Apache-2.0]: https://opensource.org/licenses/Apache-2.0

[License MIT badge]: https://img.shields.io/badge/license-MIT-blue.svg

[License MIT]: https://opensource.org/licenses/MIT

**borsh-rs** is Rust implementation of the [Borsh] binary serialization format.

Borsh stands for _Binary Object Representation Serializer for Hashing_. It is meant to be used in

security-critical projects as it prioritizes [consistency, safety, speed][Borsh], and comes with a

strict [specification](https://github.com/near/borsh#specification).

## Example

```rust

use borsh::{BorshSerialize, BorshDeserialize, from_slice, to_vec};

#[derive(BorshSerialize, BorshDeserialize, PartialEq, Debug)]

struct A {

    x: u64,

    y: String,

}

#[test]

fn test_simple_struct() {

    let a = A {

        x: 3301,

        y: "liber primus".to_string(),

    };

    let encoded_a = to_vec(&a).unwrap();

    let decoded_a = from_slice::(&encoded_a).unwrap();

    assert_eq!(a, decoded_a);

}

```


## Features

Opting out from Serde allows borsh to have some features that currently are not available for serde-compatible serializers.

Currently we support two features: `borsh(init=` and `borsh(skip)` (the former one not available in Serde).

`borsh(init=...)` allows to automatically run an initialization function right after deserialization. This adds a lot of convenience for objects that are architectured to be used as strictly immutable. Usage example:

```rust

#[derive(BorshSerialize, BorshDeserialize)]

#[borsh(init=init)]

struct Message {

    message: String,

    timestamp: u64,

    public_key: CryptoKey,

    signature: CryptoSignature

    hash: CryptoHash

}

impl Message {

    pub fn init(&mut self) {

        self.hash = CryptoHash::new().write_string(self.message).write_u64(self.timestamp);

        self.signature.verify(self.hash, self.public_key);

    }

}

```

`borsh(skip)` allows to skip serializing/deserializing fields, assuming they implement `Default` trait, similarly to `#[serde(skip)]`.

```rust

#[derive(BorshSerialize, BorshDeserialize)]

struct A {

    x: u64,

    #[borsh(skip)]

    y: f32,

}

```

### Enum with explicit discriminant

`#[borsh(use_discriminant=false|true])` is required if you have an enum with explicit discriminant. This setting affects `BorshSerialize` and `BorshDeserialize` behaviour at the same time.

In the future, borsh will drop the requirement to explicitly use `#[borsh(use_discriminant=false|true)]`, and will default to `true`, but to make sure that the transition from the older versions of borsh (before 0.11 release) does not cause silent breaking changes in de-/serialization, borsh 1.0 will require to specify if the explicit enum discriminant should be used as a de-/serialization tag value.

If you don't specify `use_discriminant` option for enum with explicit discriminant, you will get an error:

```bash

error: You have to specify `#[borsh(use_discriminant=true)]` or `#[borsh(use_discriminant=false)]` for all enums with explicit discriminant

```

In order to preserve the behaviour of borsh versions before 0.11, which did not respect explicit enum discriminants for de-/serialization, use `#[borsh(use_discriminant=false)]`, otherwise, use `true`:

```rust

#[derive(BorshDeserialize, BorshSerialize)]

#[borsh(use_discriminant=false)]

enum A {

    X,

    Y = 10,

}

```

## Testing

Integration tests should generally be preferred to unit ones. Root module of integration tests of `borsh` crate is [linked](./borsh/tests/tests.rs) here.

 

## Releasing

The versions of all public crates in this repository are collectively managed by a single version in the [workspace manifest](https://github.com/near/borsh-rs/blob/master/Cargo.toml).

So, to publish a new version of all the crates, you can do so by simply bumping that to the next "patch" version and submit a PR.

We have CI Infrastructure put in place to automate the process of publishing all crates once a version change has merged into master.

However, before you release, make sure the [CHANGELOG](CHANGELOG.md) is up to date and that the `[Unreleased]` section is present but empty.

## License

This repository is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See [LICENSE-MIT](LICENSE-MIT) and [LICENSE-APACHE](LICENSE-APACHE) for details.