Reduce default thread count

src/render/context/mod.rs

@@ -94,8 +94,8 @@ pub struct Context {
     #[arg(short = 'S', long)]
     pub follow_links: bool,
 
-    /// Number of threads to use; defaults to number of logical cores available
-    #[arg(short, long, default_value_t = Context::default_threads())]
+    /// Number of threads to use
+    #[arg(short, long, default_value_t = 3)]
     pub threads: usize,
 
     /// Omit disk usage from output; disabled by default
@@ -181,12 +181,6 @@ impl Context {
         Context::from_arg_matches(&user_args).map_err(|e| Error::ArgParse(e))
     }
 
-    fn default_threads() -> usize {
-        available_parallelism()
-            .unwrap_or_else(|_| NonZeroUsize::new(1).unwrap())
-            .get()
-    }
-
     /// Returns reference to the path of the root directory to be traversed.
     pub fn dir(&self) -> &Path {
         self.dir

src/render/tree/mod.rs

@@ -72,17 +72,12 @@ impl Tree {
     /// parallel traversal; post-processing post-processing of all directory entries should
     /// be completely CPU-bound.
     fn traverse(ctx: &Context) -> TreeResult<(Arena<Node>, NodeId)> {
-        let walker = WalkParallel::try_from(ctx)?;
         let (tx, rx) = channel::unbounded::<TraversalState>();
 
         thread::scope(|s| {
-            let mut tree = Arena::new();
-
             let res = s.spawn(|| {
-                // Key represents path of parent directory and values represent children.
+                let mut tree = Arena::new();
                 let mut branches: HashMap<PathBuf, Vec<NodeId>> = HashMap::new();
-
-                // Set used to prevent double counting hard-links in the same file-tree hiearchy.
                 let mut inodes = HashSet::new();
 
                 let mut root_id = None;
@@ -135,6 +130,8 @@ impl Tree {
 
             let mut visitor_builder = BranchVisitorBuilder::new(ctx, Sender::clone(&tx));
 
+            let walker = WalkParallel::try_from(ctx)?;
+
             walker.visit(&mut visitor_builder);
 
             tx.send(TraversalState::Done).unwrap();