Crate const_struct_version

Const-struct-version

This crate has a trait + proc-macro to generate a hash based on the fields of a struct. Useful for intelligently expiring a cache when the stored object changes.

Note that this crate is NOT perfect and may not work for all use cases, especially given our limitations with proc-macros.

Known limitations:

1. Custom derivations that have special logic we can’t see.
2. Objects that are inherently unstable/mutable.
3. Struct/Enum names that are significant to the versioning.

Feel free to open an issue if you have a use case that doesn’t work with this crate.

Features

• serde-attributes - add #[serde(XXX)] attributes into the generated hash.
• derive - derive the StructVersion trait for an object automatically.
• uuid - Support for uuid crate.
• chrono - Support for chrono crate.
• indexmap - Support for indexmap crate.
• url - Support for url crate.

Usage

[dependencies]
const_struct_version = "0.1"

use const_struct_version::StructVersion;

#[derive(StructVersion)]
pub struct Cart {
    items: Vec<String>,
    owner: String,
}

fn main() {
    println!("Cart version: {}", Cart::version_cached());
}

Contribution

Contribution are welcome! Please feel free to open an issue or a pull request.

License

Licensed under either of

• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

at your option.

Traits

StructVersion

Derive Macros

StructVersion

Derive macro implementation for the StructVersion trait