Reduce number of syscalls

2 files changed, 17 insertions, 15 deletions

diff --git a/src/main.rs b/src/main.rs
index 20b1333..966c3b3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ extern crate clap;
 extern crate humansize;
 extern crate num_cpus;
 extern crate rayon;
+extern crate crossbeam_channel;
 
 mod walk;
 
diff --git a/src/walk.rs b/src/walk.rs
index cbf0656..b80df07 100644
--- a/src/walk.rs
+++ b/src/walk.rs
@@ -2,17 +2,18 @@ use std::collections::HashSet;
 use std::fs;
 use std::os::unix::fs::MetadataExt;
 use std::path::PathBuf;
-use std::sync::mpsc::{channel, Sender};
 use std::thread;
 
+use crossbeam_channel as channel;
+
 use rayon::prelude::*;
 
 type UniqueID = (u64, u64);
 
 type SizeEntry = (Option<UniqueID>, u64);
 
-fn walk(tx: Sender<SizeEntry>, entries: &[PathBuf]) {
-    entries.par_iter().for_each_with(tx, |tx_ref, entry| {
+fn walk(tx: channel::Sender<SizeEntry>, entries: &[PathBuf]) {
+    entries.into_par_iter().for_each_with(tx, |tx_ref, entry| {
         if let Ok(metadata) = entry.metadata() {
             // If the entry has more than one hard link, generate
             // a unique ID consisting of device and inode in order
@@ -26,20 +27,20 @@ fn walk(tx: Sender<SizeEntry>, entries: &[PathBuf]) {
             let size = metadata.len();
 
             tx_ref.send((unique_id, size)).unwrap();
-        } else {
-            eprintln!("Could not get metadata: '{}'", entry.to_string_lossy());
-        };
 
-        if entry.is_dir() {
-            let mut children = vec![];
-            for child_entry in fs::read_dir(entry).unwrap() {
-                if let Ok(child_entry) = child_entry {
-                    let path = child_entry.path();
-                    children.push(PathBuf::from(path));
+            if metadata.is_dir() {
+                let mut children = vec![];
+                for child_entry in fs::read_dir(entry).unwrap() {
+                    if let Ok(child_entry) = child_entry {
+                        let path = child_entry.path();
+                        children.push(PathBuf::from(path));
+                    }
                 }
-            }
 
-            walk(tx_ref.clone(), &children[..]);
+                walk(tx_ref.clone(), &children[..]);
+            };
+        } else {
+            eprintln!("Could not get metadata: '{}'", entry.to_string_lossy());
         };
     });
 }
@@ -58,7 +59,7 @@ impl<'a> Walk<'a> {
     }
 
     pub fn run(&self) -> u64 {
-        let (tx, rx) = channel();
+        let (tx, rx) = channel::unbounded();
 
         let receiver_thread = thread::spawn(move || {
             let mut total = 0;