2 stable releases
1.0.2 | Jun 4, 2023 |
---|---|
1.0.1 | May 22, 2023 |
#2271 in Encoding
141 downloads per month
12KB
99 lines
pro-serde-versioned
This crate provides a simple method for versioning and upgrading data structures
when serialized via serde
.
Features
- The
VersionedSerialize
andVersionedDeserialize
traits allow deriving stable serialization methods for an enum, which will still work if new enum cases are added in the future - The
VersionedUpgrade
trait defines a enum sequence of struct generations by providing a method to upgrade any struct in the sequence to the latest.
VersionedSerialize
/VersionedDeserialize
Examples
use serde::{Deserialize, Serialize};
use pro_serde_versioned::{
VersionedSerialize,
VersionedDeserialize,
};
// Let's say you have two generations of some serialized data structure ...
#[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
struct MyStructV1 {
field: String
};
#[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
struct MyStructV2 {
field1: u32,
new_field: String,
}
// Derive [`VersionedSerialize`] and [`VersionedDeserialize`]
#[derive(
VersionedSerialize,
VersionedDeserialize,
Debug,
PartialEq,
Clone
)]
enum MyStructVersioned {
V1(MyStructV1),
V2(MyStructV2),
}
let versioned_struct: MyStructVersioned =
MyStructV1 { field: "123".to_string() }.into();
// Serializing `MyStructV1` to `serde_json::Value` format
let serialized_v1: serde_json::Value = versioned_struct.versioned_serialize()?;
// Deserialize `MyStructVersion` from JSON format
let deserialized_v1 = MyStructVersioned::versioned_deserialize(&serialized_v1)?;
assert_eq!(deserialized_v1, versioned_struct);
# Ok::<(), Box<dyn std::error::Error>>(())
VersionedUpgrade
Examples
use pro_serde_versioned::{
VersionedUpgrade,
Upgrade,
};
// Given the same two generations of a serialized data structure ...
#[derive(Debug, PartialEq, Clone)]
struct MyStructV1(String);
#[derive(Debug, PartialEq, Clone)]
struct MyStructV2 {
field1: u32,
new_field: String,
}
// ... and an impl for the `Upgrade` trait which links them together ...
impl Upgrade<MyStructV2> for MyStructV1 {
fn upgrade(self: MyStructV1) -> MyStructV2 {
MyStructV2 {
field1: self.0.parse().unwrap_or_default(),
new_field: "default_value".to_string(),
}
}
}
// Derive the [`VersionedUpgrade`] trait on a wrapper enum
#[derive(
VersionedUpgrade,
Debug,
PartialEq,
Clone
)]
enum MyStructVersion {
V1(MyStructV1),
V2(MyStructV2),
}
// Now any struct can be upgraded to the latest enum of [`MyStructVersioned`]!
// Upgrade `MyStructV1` to `MyStructV2`.
let upgraded_v2 =
MyStructVersion::V1(MyStructV1("123".to_string())).upgrade_to_latest();
assert_eq!(
upgraded_v2,
MyStructV2 {
field1: 123,
new_field: "default_value".to_string(),
}
);
# Ok::<(), Box<dyn std::error::Error>>(())
Dependencies
~0.7–1.7MB
~37K SLoC