fix!: return Arc instead of own in get_result(s)

BREAKING this returns an Arc<T> instead of T in the get_result methods

Signed-off-by: Amin Yahyaabadi <[email protected]>

README.md

@@ -160,7 +160,7 @@ fn main() {
     // Start executing this dag
     assert!(dag.start().unwrap());
     // Get execution result.
-    let res = dag.into_result::<usize>().unwrap();
+    let res = dag.get_result::<usize>().unwrap();
     println!("The result is {}.", res);
 }
 ```

benches/compute_dag_bench.rs

@@ -26,7 +26,7 @@ fn compute_dag(tasks: Vec<DefaultTask>) {
 
     assert!(dag.start().unwrap());
     // Get execution result.
-    let _res = dag.into_result::<usize>().unwrap();
+    let _res = dag.get_result::<usize>().unwrap();
 }
 
 fn compute_dag_bench(bencher: &mut Criterion) {

examples/compute_dag.rs

@@ -85,6 +85,6 @@ fn main() {
     // Start executing this dag
     assert!(dag.start().unwrap());
     // Get execution result.
-    let res = dag.into_result::<usize>().unwrap();
+    let res = dag.get_result::<usize>().unwrap();
     println!("The result is {}.", res);
 }

examples/engine.rs

@@ -78,6 +78,12 @@ fn main() {
     // Execute dag in order, the order should be dag1, dag2, dag3.
     assert_eq!(engine.run_sequential(), vec![true, true, true]);
     // Get the execution results of dag1 and dag2.
-    assert_eq!(engine.get_dag_result::<usize>("graph1").unwrap(), 100);
-    assert_eq!(engine.get_dag_result::<usize>("graph2").unwrap(), 1024);
+    assert_eq!(
+        engine.get_dag_result::<usize>("graph1").unwrap().as_ref(),
+        &100
+    );
+    assert_eq!(
+        engine.get_dag_result::<usize>("graph2").unwrap().as_ref(),
+        &1024
+    );
 }

src/engine/dag.rs

@@ -340,7 +340,7 @@ impl Dag {
     }
 
     /// Get the final execution result.
-    pub fn into_result<T: Send + Sync + 'static>(&self) -> Option<Arc<T>> {
+    pub fn get_result<T: Send + Sync + 'static>(&self) -> Option<Arc<T>> {
         if self.exe_sequence.is_empty() {
             None
         } else {
@@ -352,15 +352,8 @@ impl Dag {
         }
     }
 
-    /// Get the final execution result.
-    ///
-    /// Note: This method might clone the value if there are references to the value. To avoid cloning, use [`Dag::into_result`].
-    pub fn get_result<T: Send + Sync + Clone + 'static>(&self) -> Option<T> {
-        self.into_result::<T>().map(unwrap_or_clone)
-    }
-
     /// Get the output of all tasks.
-    pub fn into_results<T: Send + Sync + 'static>(&self) -> HashMap<usize, Option<Arc<T>>> {
+    pub fn get_results<T: Send + Sync + 'static>(&self) -> HashMap<usize, Option<Arc<T>>> {
         let mut hm = HashMap::new();
         for (id, state) in &self.execute_states {
             let output = match state.get_output() {
@@ -372,29 +365,8 @@ impl Dag {
         hm
     }
 
-    /// Get the output of all tasks.
-    ///
-    /// Note: This method might clone the value if there are references to the value. To avoid cloning, use [`Dag::into_results`].
-    pub fn get_results<T: Send + Sync + Clone + 'static>(&self) -> HashMap<usize, Option<T>> {
-        let mut hm = HashMap::new();
-        for (id, state) in &self.execute_states {
-            let output = match state.get_output() {
-                Some(content) => content.into_inner().map(unwrap_or_clone),
-                None => None,
-            };
-            hm.insert(*id, output);
-        }
-        hm
-    }
-
     /// Before the dag starts executing, set the dag's global environment variable.
     pub fn set_env(&mut self, env: EnvVar) {
         self.env = Arc::new(env);
     }
 }
-
-/// Unwrap an Arc<T> to T if possible, otherwise clone the value.
-// This can be removed when Arc::unwrap_or_clone is stabilized.
-fn unwrap_or_clone<T: Send + Sync + Clone + 'static>(arc: Arc<T>) -> T {
-    Arc::try_unwrap(arc).unwrap_or_else(|arc| (*arc).clone())
-}

src/engine/mod.rs

@@ -17,7 +17,7 @@ mod dag;
 mod graph;
 
 use crate::ParseError;
-use std::collections::HashMap;
+use std::{collections::HashMap, sync::Arc};
 use tokio::runtime::Runtime;
 
 /// The Engine. Manage multiple Dags.
@@ -91,7 +91,7 @@ impl Engine {
     }
 
     /// Given the name of the Dag, get the execution result of the specified Dag.
-    pub fn get_dag_result<T: Send + Sync + Clone + 'static>(&self, name: &str) -> Option<T> {
+    pub fn get_dag_result<T: Send + Sync + Clone + 'static>(&self, name: &str) -> Option<Arc<T>> {
         if self.dags.contains_key(name) {
             self.dags.get(name).unwrap().get_result()
         } else {