From 2bb8edb13cb0c2a114d8daf26cea0a4b1cda1502 Mon Sep 17 00:00:00 2001
From: Boshen <boshenc@gmail.com>
Date: Sat, 22 Jul 2023 21:13:59 +0800
Subject: [PATCH] perf(resolver): cache canonicalized path (#584)

---
 crates/oxc_resolver/src/cache.rs | 31 +++++++++++++++++++++----------
 crates/oxc_resolver/src/lib.rs   |  6 +++---
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/crates/oxc_resolver/src/cache.rs b/crates/oxc_resolver/src/cache.rs
index e9a6de4f7..0a00a94c2 100644
--- a/crates/oxc_resolver/src/cache.rs
+++ b/crates/oxc_resolver/src/cache.rs
@@ -1,7 +1,7 @@
 use std::{
     hash::BuildHasherDefault,
     path::{Path, PathBuf},
-    sync::Arc,
+    sync::{Arc, OnceLock},
 };
 
 use dashmap::DashMap;
@@ -9,6 +9,12 @@ use rustc_hash::FxHasher;
 
 use crate::{package_json::PackageJson, FileMetadata, FileSystem, ResolveError};
 
+#[derive(Debug, Clone, Default)]
+pub struct PathData {
+    meta: OnceLock<Option<FileMetadata>>,
+    symlink: OnceLock<Option<PathBuf>>,
+}
+
 pub type PackageJsonCache = DashMap<
     Box<Path>,
     Result<Option<Arc<PackageJson>>, ResolveError>,
@@ -17,7 +23,7 @@ pub type PackageJsonCache = DashMap<
 
 pub struct Cache<Fs> {
     fs: Fs,
-    cache: DashMap<Box<Path>, Option<FileMetadata>, BuildHasherDefault<FxHasher>>,
+    cache: DashMap<PathBuf, PathData, BuildHasherDefault<FxHasher>>,
     package_json_cache: PackageJsonCache,
 }
 
@@ -37,20 +43,25 @@ impl<Fs: FileSystem> Cache<Fs> {
     }
 
     fn metadata_cached(&self, path: &Path) -> Option<FileMetadata> {
-        if let Some(result) = self.cache.get(path) {
-            return *result;
-        }
-        let file_metadata = self.fs.metadata(path).ok();
-        self.cache.insert(path.to_path_buf().into_boxed_path(), file_metadata);
-        file_metadata
+        *self
+            .cache
+            .entry(path.to_path_buf())
+            .or_default()
+            .meta
+            .get_or_init(|| self.fs.metadata(path).ok())
     }
 
     pub fn is_file(&self, path: &Path) -> bool {
         self.metadata_cached(path).is_some_and(|m| m.is_file)
     }
 
-    pub fn canonicalize(&self, path: PathBuf) -> PathBuf {
-        self.fs.canonicalize(&path).unwrap_or(path)
+    pub fn canonicalize(&self, path: &Path) -> Option<PathBuf> {
+        self.cache
+            .entry(path.to_path_buf())
+            .or_default()
+            .symlink
+            .get_or_init(|| self.fs.canonicalize(path).ok())
+            .clone()
     }
 
     /// # Errors
diff --git a/crates/oxc_resolver/src/lib.rs b/crates/oxc_resolver/src/lib.rs
index 8fdbba5fc..fc342dd7f 100644
--- a/crates/oxc_resolver/src/lib.rs
+++ b/crates/oxc_resolver/src/lib.rs
@@ -89,7 +89,7 @@ impl<Fs: FileSystem> ResolverGeneric<Fs> {
                 result?
             }
         };
-        let path = self.load_symlink(path);
+        let path = self.load_symlink(&path).unwrap_or(path);
         Ok(Resolution {
             path,
             query: request.query.map(ToString::to_string),
@@ -183,8 +183,8 @@ impl<Fs: FileSystem> ResolverGeneric<Fs> {
         Ok(None)
     }
 
-    fn load_symlink(&self, path: PathBuf) -> PathBuf {
-        if self.options.symlinks { self.cache.canonicalize(path) } else { path }
+    fn load_symlink(&self, path: &Path) -> Option<PathBuf> {
+        if self.options.symlinks { self.cache.canonicalize(path) } else { None }
     }
 
     #[allow(clippy::unnecessary_wraps)]