feat: run sub workflows in the same process (#789)

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## Changes

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lib/chirp-workflow/core/src/ctx/activity.rs

@@ -2,7 +2,7 @@ use global_error::{GlobalError, GlobalResult};
 use rivet_pools::prelude::*;
 use uuid::Uuid;
 
-use crate::{ctx::OperationCtx, util, DatabaseHandle, Operation, OperationInput, WorkflowError};
+use crate::{ctx::OperationCtx, DatabaseHandle, Operation, OperationInput, WorkflowError};
 
 pub struct ActivityCtx {
 	ray_id: Uuid,
@@ -26,7 +26,19 @@ impl ActivityCtx {
 		name: &'static str,
 	) -> Self {
 		let ts = rivet_util::timestamp::now();
-		let (conn, op_ctx) = util::wrap_conn(conn, ray_id, workflow_create_ts, true, name, ts);
+		let req_id = Uuid::new_v4();
+		let conn = conn.wrap(req_id, ray_id, name);
+		let mut op_ctx = rivet_operation::OperationContext::new(
+			name.to_string(),
+			std::time::Duration::from_secs(60),
+			conn.clone(),
+			req_id,
+			ray_id,
+			ts,
+			workflow_create_ts,
+			(),
+		);
+		op_ctx.from_workflow = true;
 
 		ActivityCtx {
 			ray_id,

lib/chirp-workflow/core/src/ctx/operation.rs

@@ -2,7 +2,7 @@ use global_error::{GlobalError, GlobalResult};
 use rivet_pools::prelude::*;
 use uuid::Uuid;
 
-use crate::{util, DatabaseHandle, Operation, OperationInput, WorkflowError};
+use crate::{DatabaseHandle, Operation, OperationInput, WorkflowError};
 
 pub struct OperationCtx {
 	ray_id: Uuid,
@@ -27,7 +27,19 @@ impl OperationCtx {
 		name: &'static str,
 	) -> Self {
 		let ts = rivet_util::timestamp::now();
-		let (conn, op_ctx) = util::wrap_conn(conn, ray_id, req_ts, from_workflow, name, ts);
+		let req_id = Uuid::new_v4();
+		let conn = conn.wrap(req_id, ray_id, name);
+		let mut op_ctx = rivet_operation::OperationContext::new(
+			name.to_string(),
+			std::time::Duration::from_secs(60),
+			conn.clone(),
+			req_id,
+			ray_id,
+			ts,
+			req_ts,
+			(),
+		);
+		op_ctx.from_workflow = from_workflow;
 
 		OperationCtx {
 			ray_id,

lib/chirp-workflow/core/src/ctx/workflow.rs

@@ -420,8 +420,7 @@ impl WorkflowCtx {
 		}
 	}
 
-	// TODO(RVTEE-103): Run sub workflow inline as a branch of the parent workflow
-	/// Trigger another workflow and wait for its response.
+	/// Runs a sub workflow in the same process as the current workflow and returns its response.
 	pub async fn workflow<I>(
 		&mut self,
 		input: I,
@@ -430,11 +429,66 @@ impl WorkflowCtx {
 		I: WorkflowInput,
 		<I as WorkflowInput>::Workflow: Workflow<Input = I>,
 	{
-		let sub_workflow_id = self.dispatch_workflow(input).await?;
-		let output = self
-			.wait_for_workflow::<I::Workflow>(sub_workflow_id)
-			.await?;
-		Ok(output)
+		// Lookup workflow
+		let Ok(workflow) = self.registry.get_workflow(I::Workflow::name()) else {
+			tracing::warn!(
+				id=%self.workflow_id,
+				name=%I::Workflow::name(),
+				"sub workflow not found in current registry",
+			);
+
+			// TODO(RVT-3755): If a sub workflow is dispatched, then the worker is updated to include the sub
+			// worker in the registry, this will diverge in history because it will try to run the sub worker
+			// in process during the replay
+			// If the workflow isn't in the current registry, dispatch the workflow instead
+			let sub_workflow_id = self.dispatch_workflow(input).await?;
+			let output = self
+				.wait_for_workflow::<I::Workflow>(sub_workflow_id)
+				.await?;
+
+			return Ok(output);
+		};
+
+		tracing::info!(id=%self.workflow_id, name=%I::Workflow::name(), "running sub workflow");
+
+		// Create a new branched workflow context for the sub workflow
+		let mut ctx = WorkflowCtx {
+			workflow_id: self.workflow_id,
+			name: I::Workflow::name().to_string(),
+			create_ts: rivet_util::timestamp::now(),
+			ray_id: self.ray_id,
+
+			registry: self.registry.clone(),
+			db: self.db.clone(),
+
+			conn: self
+				.conn
+				.wrap(Uuid::new_v4(), self.ray_id, I::Workflow::name()),
+
+			event_history: self.event_history.clone(),
+
+			// TODO(RVT-3756): This is redundant with the deserialization in `workflow.run` in the registry
+			input: Arc::new(serde_json::to_value(input)?),
+
+			root_location: self
+				.root_location
+				.iter()
+				.cloned()
+				.chain(std::iter::once(self.location_idx))
+				.collect(),
+			location_idx: 0,
+		};
+
+		self.location_idx += 1;
+
+		// Run workflow
+		let output = (workflow.run)(&mut ctx).await?;
+
+		// TODO: RVT-3756
+		// Deserialize output
+		serde_json::from_value(output)
+			.map_err(WorkflowError::DeserializeWorkflowOutput)
+			.map_err(GlobalError::raw)
 	}
 
 	/// Run activity. Will replay on failure.

lib/chirp-workflow/core/src/db/postgres.rs

@@ -413,7 +413,7 @@ impl Database for DatabasePostgres {
 					INSERT INTO db_workflow.workflows (
 						workflow_id, workflow_name, create_ts, ray_id, input, wake_immediate
 					)
-					VALUES ($5, $2, $3, $4, $5, true)
+					VALUES ($7, $2, $3, $4, $5, true)
 					RETURNING 1
 			 	),
 				sub_workflow AS (

lib/chirp-workflow/core/src/util.rs

@@ -136,40 +136,3 @@ pub(crate) fn new_conn(
 
 	rivet_connection::Connection::new(client, pools.clone(), cache.clone())
 }
-
-pub fn wrap_conn(
-	conn: &rivet_connection::Connection,
-	ray_id: Uuid,
-	req_ts: i64,
-	from_workflow: bool,
-	name: &str,
-	ts: i64,
-) -> (
-	rivet_connection::Connection,
-	rivet_operation::OperationContext<()>,
-) {
-	let req_id = Uuid::new_v4();
-	let trace_entry = chirp_client::TraceEntry {
-		context_name: name.to_string(),
-		req_id: Some(req_id.into()),
-		ts,
-		run_context: match rivet_util::env::run_context() {
-			rivet_util::env::RunContext::Service => chirp_client::RunContext::Service,
-			rivet_util::env::RunContext::Test => chirp_client::RunContext::Test,
-		} as i32,
-	};
-	let conn = conn.wrap(req_id, ray_id, trace_entry);
-	let mut op_ctx = rivet_operation::OperationContext::new(
-		name.to_string(),
-		std::time::Duration::from_secs(60),
-		conn.clone(),
-		req_id,
-		ray_id,
-		ts,
-		req_ts,
-		(),
-	);
-	op_ctx.from_workflow = from_workflow;
-
-	(conn, op_ctx)
-}

lib/chirp-workflow/core/src/worker.rs

@@ -21,6 +21,7 @@ impl Worker {
 
 	pub async fn start(mut self, pools: rivet_pools::Pools) -> GlobalResult<()> {
 		let mut interval = tokio::time::interval(TICK_INTERVAL);
+		interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
 
 		let shared_client = chirp_client::SharedClient::from_env(pools.clone())?;
 		let cache = rivet_cache::CacheInner::from_env(pools.clone())?;
@@ -31,7 +32,7 @@ impl Worker {
 		}
 	}
 
-	// Query the database for new workflows and run them.
+	/// Query the database for new workflows and run them.
 	async fn tick(
 		&mut self,
 		shared_client: &chirp_client::SharedClientHandle,