Vincent Herlemont
169 lines
6.4 KiB
Markdown
169 lines
6.4 KiB
Markdown
# Native model
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[](https://crates.io/crates/native_model)
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[](https://github.com/vincent-herlemont/native_model/actions/workflows/build_and_test_release.yml)
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[](https://docs.rs/native_model)
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[](LICENSE)
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A thin wrapper around serialized data which add information of identity and version.
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## Goals
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- **Interoperability**: Allows different applications to work together, even if they are using different
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versions of the data model.
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- **Data Consistency**: Ensure that we process the data expected model.
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- **Flexibility**: You can use any serialization format you want. More details [here](#setup-your-serialization-format).
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- **Performance**: A minimal overhead. More details [here](#performance).
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## Usage
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```
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Application 1 (DotV1) Application 2 (DotV1 and DotV2)
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Encode DotV1 |----------------------------------------> | Decode DotV1 to DotV2
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| | Modify DotV2
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Decode DotV1 | <----------------------------------------| Encode DotV2 back to DotV1
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```
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```rust,skt-main
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// Application 1
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let dot = DotV1(1, 2);
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let bytes = native_model::encode(&dot).unwrap();
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// Application 1 sends bytes to Application 2.
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// Application 2
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// We are able to decode the bytes directly into a new type DotV2.
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let (mut dot, source_version) = native_model::decode::<DotV2>(bytes).unwrap();
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assert_eq!(dot, DotV2 {
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name: "".to_string(),
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x: 1,
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y: 2
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});
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dot.name = "Dot".to_string();
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dot.x = 5;
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// For interoperability, we encode the data with the version compatible with Application 1.
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let bytes = native_model::encode_downgrade(dot, source_version).unwrap();
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// Application 2 sends bytes to Application 1.
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// Application 1
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let (dot, _) = native_model::decode::<DotV1>(bytes).unwrap();
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assert_eq!(dot, DotV1(5, 2));
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```
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Full example [here](./tests/example/example_main.rs).
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When use it?
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- Your applications that interact with each other are written in Rust.
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- Your applications evolve independently need to read serialized data coming from each other.
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- Your applications store data locally and need to read it later by a newer version of the application.
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- Your systems need to be upgraded incrementally. Instead of having to upgrade the entire system at once, individual
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applications can be upgraded one at a time, while still being able to communicate with each other.
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When not use it?
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- Your applications that interact with each other are **not all** written in Rust.
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- Your applications need to communicate with other systems that you don't control.
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- You need to have a human-readable format. (You can use a human-readable format like JSON wrapped in a native model,
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but you have to unwrap it to see the data correctly.)
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# Status
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Early development. Not ready for production.
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## Setup your serialization format
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First, you need to set up your serialization format. You can use any serialization format.
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Just define the following functions, so they must be imported in the scope where you use the native model.
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```rust,ignore
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fn native_model_encode_body<T: Encode>(obj: &T) -> Result<Vec<u8>, dyn Error> {
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...
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}
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fn native_model_decode_body<T: Decode>(data: Vec<u8>) -> Result<T, dyn Error> {
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...
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}
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```
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Examples:
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- [bincode with encode/decode](./tests/example/encode_decode/bincode.rs)
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- [bincode with serde](./tests/example/encode_decode/bincode_serde.rs)
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## Setup your data model
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Define your model using the macro [`native_model`](file:///home/vincentherlemont/IdeaProjects/native_model/target/doc/native_model/attr.native_model.html).
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Attributes:
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- `id = u32`: The unique identifier of the model.
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- `version = u32`: The version of the model.
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- `from = type`: Optional, the previous version of the model.
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- `type`: The previous version of the model that you use for the From implementation.
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- `try_from = (type, error)`: Optional, the previous version of the model with error handling.
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- `type`: The previous version of the model that you use for the TryFrom implementation.
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- `error`: The error type that you use for the TryFrom implementation.
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```rust,skt-define-models
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use native_model::native_model;
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#[derive(Encode, Decode, PartialEq, Debug)]
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#[native_model(id = 1, version = 1)]
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struct DotV1(u32, u32);
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#[derive(Encode, Decode, PartialEq, Debug)]
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#[native_model(id = 1, version = 2, from = DotV1)]
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struct DotV2 {
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name: String,
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x: u64,
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y: u64,
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}
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// Implement the conversion between versions From<DotV1> for DotV2 and From<DotV2> for DotV1.
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#[derive(Encode, Decode, PartialEq, Debug)]
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#[native_model(id = 1, version = 3, try_from = (DotV2, anyhow::Error))]
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struct DotV3 {
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name: String,
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cord: Cord,
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}
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#[derive(Encode, Decode, PartialEq, Debug)]
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struct Cord {
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x: u64,
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y: u64,
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}
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// Implement the conversion between versions From<DotV2> for DotV3 and From<DotV3> for DotV2.
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```
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Full example [here](tests/example/example_define_model.rs).
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# Performance
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This crate is in an early stage of development, so the performance should be improved in the future.
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The goal is to have a minimal and constant overhead for all data sizes. It uses the [zerocopy](https://docs.rs/zerocopy/latest/zerocopy/) crate to avoid unnecessary copies.
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Current performance:
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- Encode time: have overhead that evolves linearly with the data size.
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- Decode time: have overhead of ~162 ps for all data sizes.
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| data size | encode time (ns/ps/µs/ms) | decode time (ps) |
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|:---------------------:|:--------------------------:|:----------------:|
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| 1 B | 40.093 ns - 40.510 ns | 161.87 ps - 162.02 ps |
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| 1 KiB (1024 B) | 116.45 ns - 116.83 ns | 161.85 ps - 162.08 ps |
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| 1 MiB (1048576 B) | 66.697 µs - 67.634 µs | 161.87 ps - 162.18 ps |
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| 10 MiB (10485760 B) | 1.5670 ms - 1.5843 ms | 162.40 ps - 163.52 ps |
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| 100 MiB (104857600 B) | 63.778 ms - 64.132 ms | 162.71 ps - 165.10 ps |
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Benchmark of the native model overhead [here](benches/overhead.rs).
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To know how much time it takes to encode/decode your data, you need to add this overhead to the time of your serialization format.
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