Add support for attaching data to the context.

examples/data_in_context.rs

@@ -0,0 +1,44 @@
+use hatchet_sdk::{Client, Context, StepBuilder, WorkflowBuilder};
+
+#[derive(serde::Deserialize)]
+struct Input {}
+
+async fn execute(context: Context, _input: Input) -> anyhow::Result<()> {
+    assert_eq!(context.datum::<Datum>().number, 10);
+    Ok(())
+}
+
+struct Datum {
+    number: usize,
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    dotenv::dotenv().ok();
+    tracing_subscriber::fmt()
+        .with_target(false)
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::from_default_env()
+                .add_directive("hatchet_sdk=debug".parse()?),
+        )
+        .init();
+
+    let client = Client::new()?;
+    let mut worker = client
+        .worker("example_data_in_context")
+        .datum(Datum { number: 10 })
+        .build();
+    worker.register_workflow(
+        WorkflowBuilder::default()
+            .name("example_data_in_context")
+            .step(
+                StepBuilder::default()
+                    .name("compute")
+                    .function(&execute)
+                    .build()?,
+            )
+            .build()?,
+    );
+    worker.start().await?;
+    Ok(())
+}

examples/fibonacci.rs

@@ -1,4 +1,4 @@
-use hatchet_sdk::{Client, Context, StepBuilder, WorkflowBuilder};
+use hatchet_sdk::{Client, StepBuilder, WorkflowBuilder};
 
 fn fibonacci(n: u32) -> u32 {
     (1..=n)

src/step_function.rs

@@ -1,8 +1,16 @@
+use std::{
+    any::{Any, TypeId},
+    collections::HashMap,
+    sync::Arc,
+};
+
 use futures_util::lock::Mutex;
 use tracing::info;
 
 use crate::worker::{grpc, ServiceWithAuthorization};
 
+pub(crate) type DataMap = HashMap<TypeId, Box<dyn Any + Send + Sync>>;
+
 pub struct Context {
     workflow_run_id: String,
     workflow_step_run_id: String,
@@ -15,6 +23,7 @@ pub struct Context {
         >,
         u16,
     )>,
+    data: Arc<DataMap>,
 }
 
 impl Context {
@@ -27,14 +36,24 @@ impl Context {
                 ServiceWithAuthorization,
             >,
         >,
+        data: Arc<DataMap>,
     ) -> Self {
         Self {
             workflow_run_id,
             workflow_service_client_and_spawn_index: Mutex::new((workflow_service_client, 0)),
             workflow_step_run_id,
+            data,
         }
     }
 
+    pub fn datum<D: std::any::Any + Send + Sync>(&self) -> &D {
+        let type_id = TypeId::of::<D>();
+        self.data
+            .get(&type_id)
+            .and_then(|value| value.downcast_ref())
+            .unwrap_or_else(|| panic!("could not find an attached datum of the type: {type_id:?}"))
+    }
+
     pub async fn trigger_workflow<I: serde::Serialize>(
         &self,
         workflow_name: &str,

src/worker/listener.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use futures_util::FutureExt;
 use tokio::task::LocalSet;
 use tonic::IntoRequest;
@@ -14,7 +16,7 @@ use super::{
         dispatcher_client::DispatcherClient, AssignedAction, StepActionEvent, StepActionEventType,
         WorkerListenRequest,
     },
-    ListenStrategy, ServiceWithAuthorization,
+    DataMap, ListenStrategy, ServiceWithAuthorization,
 };
 
 const DEFAULT_ACTION_LISTENER_RETRY_INTERVAL: std::time::Duration =
@@ -63,6 +65,7 @@ async fn handle_start_step_run(
     worker_id: &str,
     workflows: &[Workflow],
     action: AssignedAction,
+    data: Arc<DataMap>,
 ) -> crate::InternalResult<()> {
     let Some(action_callable) = workflows
         .iter()
@@ -101,6 +104,7 @@ async fn handle_start_step_run(
                     workflow_run_id,
                     workflow_step_run_id,
                     workflow_service_client,
+                    data,
                 );
                 action_callable(context, input.input).await
             })
@@ -155,7 +159,7 @@ pub(crate) async fn run(
     workflows: Vec<Workflow>,
     listener_v2_timeout: Option<u64>,
     mut interrupt_receiver: tokio::sync::mpsc::Receiver<()>,
-    _heartbeat_interrupt_sender: tokio::sync::mpsc::Sender<()>,
+    data: Arc<DataMap>,
 ) -> crate::InternalResult<()> {
     use futures_util::StreamExt;
 
@@ -253,7 +257,7 @@ pub(crate) async fn run(
 
                     match action_type {
                         ActionType::StartStepRun => {
-                            handle_start_step_run(&mut dispatcher, workflow_service_client.clone(), &local_set, namespace, worker_id, &workflows, action).await?;
+                            handle_start_step_run(&mut dispatcher, workflow_service_client.clone(), &local_set, namespace, worker_id, &workflows, action, data.clone()).await?;
                         }
                         ActionType::CancelStepRun => {
                             todo!()

src/worker/mod.rs

@@ -1,14 +1,16 @@
 mod heartbeat;
 mod listener;
 
+use std::sync::Arc;
+
 use grpc::{
     CreateWorkflowJobOpts, CreateWorkflowStepOpts, CreateWorkflowVersionOpts, PutWorkflowRequest,
     WorkerRegisterRequest, WorkerRegisterResponse, WorkflowKind,
 };
 use tonic::transport::Certificate;
 use tracing::info;
 
-use crate::{client::Environment, ClientTlStrategy, Workflow};
+use crate::{client::Environment, step_function::DataMap, ClientTlStrategy, Workflow};
 
 #[derive(Clone)]
 pub(crate) struct ServiceWithAuthorization {
@@ -55,9 +57,18 @@ pub struct Worker<'a> {
     environment: &'a super::client::Environment,
     #[builder(default, setter(skip))]
     workflows: Vec<Workflow>,
+    #[builder(default, setter(custom))]
+    data: DataMap,
 }
 
 impl<'a> WorkerBuilder<'a> {
+    pub fn datum<D: std::any::Any + Send + Sync>(mut self, datum: D) -> Self {
+        self.data
+            .get_or_insert_default()
+            .insert(std::any::TypeId::of::<D>(), Box::new(datum));
+        self
+    }
+
     pub fn build(self) -> Worker<'a> {
         self.build_private().expect("must succeed")
     }
@@ -172,7 +183,7 @@ impl<'a> Worker<'a> {
         let (listening_interrupt_sender1, listening_interrupt_receiver) =
             tokio::sync::mpsc::channel(1);
         let _listening_interrupt_sender2 = listening_interrupt_sender1.clone();
-        let heartbeat_interrupt_sender2 = heartbeat_interrupt_sender1.clone();
+        let _heartbeat_interrupt_sender2 = heartbeat_interrupt_sender1.clone();
 
         tokio::spawn(async move {
             tokio::signal::ctrl_c().await.unwrap();
@@ -182,6 +193,14 @@ impl<'a> Worker<'a> {
             let _ = listening_interrupt_sender1.send(()).await;
         });
 
+        let Self {
+            workflows,
+            data,
+            name,
+            max_runs,
+            environment,
+        } = self;
+
         let Environment {
             token,
             host_port,
@@ -195,7 +214,7 @@ impl<'a> Worker<'a> {
             tls_server_name,
             namespace,
             listener_v2_timeout,
-        } = self.environment;
+        } = environment;
 
         let endpoint = construct_endpoint(
             tls_server_name.as_deref(),
@@ -220,7 +239,9 @@ impl<'a> Worker<'a> {
 
         let mut all_actions = vec![];
 
-        for workflow in &self.workflows {
+        let data = Arc::new(data);
+
+        for workflow in &workflows {
             let namespaced_workflow_name =
                 format!("{namespace}{workflow_name}", workflow_name = workflow.name);
 
@@ -284,8 +305,8 @@ impl<'a> Worker<'a> {
 
         let request = {
             let mut request: tonic::Request<WorkerRegisterRequest> = WorkerRegisterRequest {
-                worker_name: self.name.clone(),
-                max_runs: self.max_runs,
+                worker_name: name,
+                max_runs,
                 services: vec!["default".to_owned()],
                 actions: all_actions,
                 // FIXME: Implement.
@@ -304,7 +325,7 @@ impl<'a> Worker<'a> {
 
         futures_util::try_join! {
             heartbeat::run(dispatcher.clone(), &worker_id, heartbeat_interrupt_receiver),
-            listener::run(dispatcher, workflow_service_client, namespace, &worker_id, self.workflows, *listener_v2_timeout, listening_interrupt_receiver, heartbeat_interrupt_sender2),
+            listener::run(dispatcher, workflow_service_client, namespace, &worker_id, workflows, *listener_v2_timeout, listening_interrupt_receiver, data)
         }?;
 
         Ok(())