Use Rust 1.70, address some of Clippy's advice

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.70.0"
+components = ["rustfmt", "clippy"]

src/build.rs

@@ -833,7 +833,7 @@ impl BuildMetaIndex {
             file_id: file_id,
             title: StringRef(title),
             artist: StringRef(track_artist),
-            duration_seconds: file.duration_seconds as u16,
+            duration_seconds: file.duration_seconds,
             filename: file.filename,
             loudness: track_loudness,
         };

src/playback.rs

@@ -532,7 +532,7 @@ pub fn main(
             play_queue(
                 &config.audio_device,
                 &config.audio_volume_control,
-                &*state_mutex,
+                &state_mutex,
                 decode_thread,
             );
             println!("Playback done, sleeping ...");

src/player.rs

@@ -75,8 +75,8 @@ pub struct Format {
     pub bits_per_sample: u32,
 }
 
-impl Format {
-    pub fn default() -> Format {
+impl Default for Format {
+    fn default() -> Format {
         Format {
             sample_rate: Hertz(44_100),
             bits_per_sample: 16,
@@ -1031,7 +1031,7 @@ fn decode_main(
 
         if should_decode {
             let current_index = index.get();
-            decode_burst(&*current_index, state_mutex, &mut filters);
+            decode_burst(&current_index, state_mutex, &mut filters);
         }
 
         println!("Decoder going to sleep.");
@@ -1101,7 +1101,7 @@ impl Player {
             .spawn(move || {
                 decode_main(
                     index_for_decode,
-                    &*state_mutex_for_decode,
+                    &state_mutex_for_decode,
                     high_pass_cutoff,
                 );
             }).unwrap();
@@ -1174,8 +1174,8 @@ impl Player {
         let album_id = track_id.album_id();
         let track = index.get_track(track_id).expect("Can only enqueue existing tracks.");
         let album = index.get_album(album_id).expect("Track must belong to album.");
-        let track_loudness = track.loudness.unwrap_or_else(Lufs::default);
-        let album_loudness = album.loudness.unwrap_or_else(Lufs::default);
+        let track_loudness = track.loudness.unwrap_or_default();
+        let album_loudness = album.loudness.unwrap_or_default();
 
         // If the queue is empty, then the playback thread may be parked,
         // so we may need to wake it after enqueuing something.

src/prim.rs

@@ -176,8 +176,10 @@ impl Lufs {
             .expect("A value of 0.0 LUFS is not allowed, use -0.01 LUFS instead.")
         )
     }
+}
 
-    pub fn default() -> Lufs {
+impl Default for Lufs {
+    fn default() -> Lufs {
         Lufs(std::num::NonZeroI16::new(-900).unwrap())
     }
 }

src/scan.rs

@@ -636,7 +636,7 @@ pub fn run_scan_in_thread(
                 tx.send(status).unwrap();
 
                 let mut loudness_tasks = loudness::TaskQueue::new(
-                    &*index_arc,
+                    &index_arc,
                     &mut status,
                     &mut tx,
                 );
@@ -653,7 +653,7 @@ pub fn run_scan_in_thread(
             // If there are any new or updated albums, regenerate thumbnails for
             // those.
             crate::thumb_gen::generate_thumbnails(
-                &*index_arc,
+                &index_arc,
                 &db_path,
                 &mut status,
                 &mut tx,

src/thumb_cache.rs

@@ -87,7 +87,7 @@ impl ThumbCache {
     ///
     /// See also [`load_from_database`].
     pub fn load_from_database_at(db_path: &Path) -> db::Result<ThumbCache> {
-        let inner = database_utils::connect_readonly(&db_path)?;
+        let inner = database_utils::connect_readonly(db_path)?;
         let mut conn = db::Connection::new(&inner);
         let mut tx = conn.begin()?;
         let result = ThumbCache::load_from_database(&mut tx)?;

src/thumb_gen.rs

@@ -115,27 +115,27 @@ impl<'a> GenThumb<'a> {
             // thumbnail become darker, which is especially noticeable for
             // covers with white edges, and also shows up as a "pop" in the
             // album view when the full-resolution image loads.
-            .args(&["-background", "black"])
-            .args(&["-alpha", "remove"])
-            .args(&["-alpha", "off"])
-            .args(&["-flatten"])
+            .args(["-background", "black"])
+            .args(["-alpha", "remove"])
+            .args(["-alpha", "off"])
+            .args(["-flatten"])
             // Resize in a linear color space, sRGB is not suitable for it
             // because it is nonlinear. "RGB" in ImageMagick is linear.
-            .args(&["-colorspace", "RGB"])
+            .args(["-colorspace", "RGB"])
             // See also the note about -flatten above. I think Edge is the
             // default, but let's be explicit about it.
-            .args(&["-virtual-pixel", "Edge"])
+            .args(["-virtual-pixel", "Edge"])
             // Lanczos2 is a bit less sharp than Cosine, but less sharp edges
             // means that the image compresses better, and less artifacts. But
             // still, Lanczos was too blurry in my opinion.
-            .args(&["-filter", "Cosine"])
+            .args(["-filter", "Cosine"])
             // Twice the size of the thumb in the webinterface, so they appear
             // pixel-perfect on a high-DPI display, or on a mobile phone.
-            .args(&["-distort", "Resize", "140x140!"])
-            .args(&["-colorspace", "sRGB"])
+            .args(["-distort", "Resize", "140x140!"])
+            .args(["-colorspace", "sRGB"])
             // Remove EXIF metadata, including the colour profile if there was
             // any -- we convert to sRGB anyway.
-            .args(&["-strip"])
+            .args(["-strip"])
             // Write lossless, we will later compress to jpeg with Guetzli,
             // which has a better compressor.
             .arg(&out_path)
@@ -172,7 +172,7 @@ impl<'a> GenThumb<'a> {
             .map_err(|e| Error::CommandError("Imagemagick's 'convert' failed.", e))?;
 
         let guetzli = Command::new("guetzli")
-            .args(&["--quality", "97"])
+            .args(["--quality", "97"])
             // Input is the intermediate file.
             .arg(&out_path)
             // Output is stdout, but guetzli does not understand `-`.
@@ -212,7 +212,7 @@ impl<'a> GenThumb<'a> {
                     .map_err(|e| Error::CommandError("Guetzli failed.", e))?;
 
                 // Delete the intermediate png file.
-                std::fs::remove_file(&in_path)?;
+                std::fs::remove_file(in_path)?;
 
                 let mut stdout = child
                     .stdout

src/word_index.rs

@@ -130,10 +130,10 @@ impl WordMeta {
     /// Return a copy of the word meta, with log-frequency filled in.
     fn set_frequency(self, frequency: u64) -> WordMeta {
         debug_assert!(frequency > 0, "Frequency must be positive.");
-        let log2_frequency = 63 - frequency.leading_zeros();
+        let log2_frequency: u32 = 63 - frequency.leading_zeros();
 
         // The 6-bit log-frequency is at offset 24.
-        WordMeta(self.0 | ((log2_frequency as u32) << 24))
+        WordMeta(self.0 | (log2_frequency << 24))
     }
 }