Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[NOMERGE] Rust SDK future proposal draft #550

Draft
wants to merge 3 commits into
base: master
Choose a base branch
from
Draft
Changes from 1 commit
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Activity definition
Sushisource committed May 12, 2023
commit a36ab43cc1847730123bd866de5111f49d75cf34
1 change: 1 addition & 0 deletions sdk/src/lib.rs
Original file line number Diff line number Diff line change
@@ -47,6 +47,7 @@
mod activity_context;
mod app_data;
pub mod interceptors;
pub mod new_activity_defs;

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / build-and-test

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / build-and-test

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / build-and-test

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / Integ tests

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / Integ tests

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / Integ tests

missing documentation for a module

Check warning on line 50 in sdk/src/lib.rs

GitHub Actions / Unit Tests

missing documentation for a module
mod payload_converter;
mod workflow_context;
mod workflow_future;
Empty file added sdk/src/new_activity_defs.rs
Empty file.
43 changes: 43 additions & 0 deletions workflow-api/src/activity_definitions.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,43 @@
use crate::WfContext;
use futures::future::BoxFuture;

// #[activity_definition]
type MyActFn = fn(String) -> String;

// Macro enforces types are serializable.

// The biggest problem with activity definitions is they need to be defined in a crate which doesn't
// depend on the entire SDK, because then the workflow code which uses them wouldn't be able to
// be compiled down to WASM. Of course, the issue is activities _aren't_ compiled to WASM, and need
// access to full native functionality. Thus users need to structure their app a bit oddly. They
// can either define all their workflow code & activity _definitions_ in one crate, and then
// depend on that crate from another crate containing their activity implementations / worker, or
// they could make a crate with *just* activity definitions, which is depended on by the workflow
// implementation crate and the worker crate independently. It all makes perfect sense, but is
// maybe a bit annoying in terms of setup - though not really any worse than TS.

// Macro generates this extension & implementation:
//
// The generated code taking `impl Into<Argtype>` is quite nice for ergonomics inside the workflow,
// but might be impossible in some cases, so probably macro would need a flag to turn it off.
pub trait MyActFnWfCtxExt {
// In reality this returns the `CancellableFuture` type from SDK, would also need to move into
// this crate.
fn my_act_fn(
&self,
input: impl Into<String>,
) -> BoxFuture<'static, Result<String, ActivityFail>>;
}
impl MyActFnWfCtxExt for WfContext {
fn my_act_fn(&self, _: impl Into<String>) -> BoxFuture<'static, Result<String, ActivityFail>> {
// Type name is injected in this implementation, taken from macro
todo!()
}
}

// To implement the activity in their implementation crate, the user would do something like:
// worker.register_activity(MyActFn, |input: String| async move { .... });

// Placeholder. Activity failures as can be seen by the WF code.
#[derive(Debug)]
pub struct ActivityFail {}
5 changes: 5 additions & 0 deletions workflow-api/src/lib.rs
Original file line number Diff line number Diff line change
@@ -2,6 +2,9 @@
//! to WASM not work. I've already figured out how to do all that once before with my WASM workflows
//! hackathon

mod activity_definitions;

use activity_definitions::MyActFnWfCtxExt;
use futures::future::BoxFuture;
use std::time::Duration;
use temporal_sdk_core_protos::{
@@ -136,6 +139,8 @@ mod tests {
async move {
ctx.timer(Duration::from_secs(1)).await;
self.foo = 1;
// See activity definitions file
ctx.my_act_fn("Hi!").await.unwrap();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Concern here is how to pass in options. One reason that Java's approach of reusing actual activity signature was so rough is that you were forced to make options a separate thing.

// The into() is unfortunately unavoidable without making C-A-N and confirm cancel
// be errors instead. Personally, I don't love that and I think it's not idiomatic
// Rust, whereas needing to `into()` something is. Other way would be macros, but