From 85ba887a9ce56c94861cfc60cce6eae90b9f3a79 Mon Sep 17 00:00:00 2001
From: sharkdp <davidpeter@web.de>
Date: Sun, 4 Nov 2018 20:35:45 +0100
Subject: Move error handling to main thread

---
 src/main.rs |  2 +-
 src/walk.rs | 51 ++++++++++++++++++++++++++++++++++++---------------
 2 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 83b1027..1a17a51 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,9 @@
 #[macro_use]
 extern crate clap;
+extern crate crossbeam_channel;
 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 a5daac6..28a1059 100644
--- a/src/walk.rs
+++ b/src/walk.rs
@@ -8,12 +8,16 @@ use crossbeam_channel as channel;
 
 use rayon::prelude::*;
 
-#[derive(Eq,PartialEq,Hash)]
+#[derive(Eq, PartialEq, Hash)]
 struct UniqueID(u64, u64);
 
-struct SizeEntry(Option<UniqueID>, u64);
+enum Message {
+    SizeEntry(Option<UniqueID>, u64),
+    NoMetadataForPath(PathBuf),
+    CouldNotReadDir(PathBuf),
+}
 
-fn walk(tx: channel::Sender<SizeEntry>, entries: &[PathBuf]) {
+fn walk(tx: channel::Sender<Message>, entries: &[PathBuf]) {
     entries.into_par_iter().for_each_with(tx, |tx_ref, entry| {
         if let Ok(metadata) = entry.symlink_metadata() {
             // If the entry has more than one hard link, generate
@@ -27,20 +31,27 @@ fn walk(tx: channel::Sender<SizeEntry>, entries: &[PathBuf]) {
 
             let size = metadata.len();
 
-            tx_ref.send(SizeEntry(unique_id, size)).unwrap();
+            tx_ref.send(Message::SizeEntry(unique_id, size)).unwrap();
 
             if metadata.is_dir() {
                 let mut children = vec![];
-                for child_entry in fs::read_dir(entry).unwrap() {
-                    if let Ok(child_entry) = child_entry {
-                        children.push(child_entry.path());
+                match fs::read_dir(entry) {
+                    Ok(child_entries) => {
+                        for child_entry in child_entries {
+                            if let Ok(child_entry) = child_entry {
+                                children.push(child_entry.path());
+                            }
+                        }
+                    }
+                    Err(err) => {
+                        tx_ref.send(Message::CouldNotReadDir(entry.clone())).unwrap();
                     }
                 }
 
                 walk(tx_ref.clone(), &children[..]);
             };
         } else {
-            eprintln!("Could not get file metadata: '{}'", entry.to_string_lossy());
+            tx_ref.send(Message::NoMetadataForPath(entry.clone())).unwrap();
         };
     });
 }
@@ -64,14 +75,24 @@ impl<'a> Walk<'a> {
         let receiver_thread = thread::spawn(move || {
             let mut total = 0;
             let mut ids = HashSet::new();
-            for SizeEntry(unique_id, size) in rx {
-                if let Some(unique_id) = unique_id {
-                    // Only count this entry if the ID has not been seen
-                    if ids.insert(unique_id) {
-                        total += size;
+            for msg in rx {
+                match msg {
+                    Message::SizeEntry(unique_id, size) => {
+                        if let Some(unique_id) = unique_id {
+                            // Only count this entry if the ID has not been seen
+                            if ids.insert(unique_id) {
+                                total += size;
+                            }
+                        } else {
+                            total += size;
+                        }
+                    }
+                    Message::NoMetadataForPath(path) => {
+                        eprintln!("diskus: could not metadata for path '{}'", path.to_string_lossy());
+                    }
+                    Message::CouldNotReadDir(path) => {
+                        eprintln!("diskus: could not contents of directory '{}'", path.to_string_lossy());
                     }
-                } else {
-                    total += size;
                 }
             }
 
-- 
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