perf(IO): use parallel walkdir (jwalk) for super faster traversal

src/utils/mod.rs

@@ -2,7 +2,7 @@ use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::collections::HashSet;
 
-use walkdir::WalkDir;
+use jwalk::WalkDir;
 
 mod platform;
 use self::platform::*;
@@ -78,7 +78,7 @@ fn examine_dir(
     data: &mut HashMap<String, u64>,
     file_count_no_permission: &mut u64,
 ) {
-    for entry in WalkDir::new(top_dir) {
+    for entry in WalkDir::new(top_dir).preload_metadata(true) {
         if let Ok(e) = entry {
             let maybe_size_and_inode = get_metadata(&e, apparent_size);
 
@@ -93,12 +93,12 @@ fn examine_dir(
                         }
                     }
                     // This path and all its parent paths have their counter incremented
-                    let mut e_path = e.path().to_path_buf();
+                    let mut e_path = e.path();
                     loop {
                         let path_name = e_path.to_string_lossy().to_string();
                         let s = data.entry(path_name.clone()).or_insert(0);
                         *s += size;
-                        if path_name == *top_dir {
+                        if path_name == top_dir || path_name == "/" {
                             break;
                         }
                         assert!(path_name != "");

src/utils/platform.rs

@@ -1,4 +1,4 @@
-use walkdir::DirEntry;
+use jwalk::DirEntry;
 
 fn get_block_size() -> u64 {
     // All os specific implementations of MetatdataExt seem to define a block as 512 bytes
@@ -9,17 +9,22 @@ fn get_block_size() -> u64 {
 #[cfg(target_family = "unix")]
 pub fn get_metadata(d: &DirEntry, use_apparent_size: bool) -> Option<(u64, Option<(u64, u64)>)> {
     use std::os::unix::fs::MetadataExt;
-    d.metadata().ok().and_then(|md| {
+    d.metadata.as_ref().unwrap().as_ref().ok().map(|md| {
         let inode = Some((md.ino(), md.dev()));
         if use_apparent_size {
-            Some((md.len(), inode))
+            (md.len(), inode)
         } else {
-            Some((md.blocks() * get_block_size(), inode))
+            (md.blocks() * get_block_size(), inode)
         }
     })
 }
 
 #[cfg(not(target_family = "unix"))]
 pub fn get_metadata(d: &DirEntry, _apparent: bool) -> Option<(u64, Option<(u64, u64)>)> {
-    d.metadata().ok().map_or(None, |md| Some((md.len(), None)))
+    d.metadata
+        .as_ref()
+        .unwrap()
+        .as_ref()
+        .ok()
+        .map(|md| (md.len(), None))
 }