perf: hard link npm cache (#22773)

1 files changed, 6 insertions, 2 deletions

diff --git a/cli/npm/managed/resolvers/local.rs b/cli/npm/managed/resolvers/local.rs
index 88368cdd2..34e0fae09 100644
--- a/cli/npm/managed/resolvers/local.rs
+++ b/cli/npm/managed/resolvers/local.rs
@@ -332,8 +332,12 @@ async fn sync_resolution_with_fs(
           .with_context(|| format!("Creating '{}'", folder_path.display()))?;
         let cache_folder = cache
           .package_folder_for_name_and_version(&package.id.nv, &registry_url);
-        // for now copy, but in the future consider hard linking
-        copy_dir_recursive(&cache_folder, &package_path)?;
+        if hard_link_dir_recursive(&cache_folder, &package_path).is_err() {
+          // Fallback to copying the directory.
+          //
+          // Also handles EXDEV when when trying to hard link across volumes.
+          copy_dir_recursive(&cache_folder, &package_path)?;
+        }
         // write out a file that indicates this folder has been initialized
         fs::write(initialized_file, "")?;
         // finally stop showing the progress bar