Assure we don't keep threads around unnecessarily in interactive mode

2 files changed, 8 insertions, 3 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 794c662..5abc996 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ itertools = "0.8.0"
 open = "1.2.2"
 log = "0.4.6"
 tui-react = { path = "./tui-react", version = "0.1" }
+num_cpus = "1.10.0"
 
 [[bin]]
 name="dua"
diff --git a/src/traverse.rs b/src/traverse.rs
index d6ef957..dc28579 100644
--- a/src/traverse.rs
+++ b/src/traverse.rs
@@ -35,7 +35,7 @@ pub struct Traversal {
 
 impl Traversal {
     pub fn from_walk(
-        options: WalkOptions,
+        mut walk_options: WalkOptions,
         input: Vec<PathBuf>,
         mut update: impl FnMut(&Traversal) -> Result<(), Error>,
     ) -> Result<Traversal, Error> {
@@ -73,10 +73,14 @@ impl Traversal {
         const INITIAL_CHECK_INTERVAL: usize = 500;
         let mut check_instant_every = INITIAL_CHECK_INTERVAL;
         let mut last_seen_eid;
-
+        if walk_options.threads == 0 {
+            // avoid using the global rayon pool, as it will keep a lot of threads alive after we are done.
+            // Also means that we will spin up a bunch of threads per root path, instead of reusing them.
+            walk_options.threads = num_cpus::get_physical();
+        }
         for path in input.into_iter() {
             last_seen_eid = 0;
-            for (eid, entry) in options
+            for (eid, entry) in walk_options
                 .iter_from_path(path.as_ref())
                 .into_iter()
                 .enumerate()