deployment: Move chunked mode into self-contained function

src/nix/deployment/mod.rs

@@ -164,17 +164,10 @@ impl Deployment {
             Ok(())
         } else {
             // Do the whole eval-build-deploy flow
-            let chunks = self.get_chunks();
+            let targets = mem::replace(&mut self.targets, HashMap::new());
             let deployment = DeploymentHandle::new(self);
             let meta_future = meta.run(|meta| async move {
-                let mut futures = Vec::new();
-
-                for chunk in chunks.into_iter() {
-                    futures.push(deployment.execute_chunk(meta.clone(), chunk));
-                }
-
-                join_all(futures).await
-                    .into_iter().collect::<ColmenaResult<Vec<()>>>()?;
+                deployment.execute_chunked(meta.clone(), targets).await?;
 
                 Ok(())
             });
@@ -202,25 +195,33 @@ impl Deployment {
         self.evaluation_node_limit = limit;
     }
 
-    fn get_chunks(&mut self) -> Vec<TargetNodeMap> {
+    /// Executes the deployment on selected nodes, evaluating a chunk at a time.
+    async fn execute_chunked(self: &DeploymentHandle, parent: JobHandle, mut targets: TargetNodeMap)
+        -> ColmenaResult<()>
+    {
         let eval_limit = self.evaluation_node_limit.get_limit()
             .unwrap_or_else(|| self.targets.len());
 
-        let mut result = Vec::new();
+        let mut futures = Vec::new();
 
-        for chunk in self.targets.drain().chunks(eval_limit).into_iter() {
+        for chunk in targets.drain().chunks(eval_limit).into_iter() {
             let mut map = HashMap::new();
             for (name, host) in chunk {
                 map.insert(name, host);
             }
-            result.push(map);
+
+            futures.push(self.execute_one_chunk(parent.clone(), map));
         }
 
-        result
+        join_all(futures).await
+            .into_iter()
+            .collect::<ColmenaResult<Vec<()>>>()?;
+
+        Ok(())
     }
 
     /// Executes the deployment against a portion of nodes.
-    async fn execute_chunk(self: &DeploymentHandle, parent: JobHandle, mut chunk: TargetNodeMap) -> ColmenaResult<()> {
+    async fn execute_one_chunk(self: &DeploymentHandle, parent: JobHandle, mut chunk: TargetNodeMap) -> ColmenaResult<()> {
         if self.goal == Goal::UploadKeys {
             unreachable!(); // some logic is screwed up
         }