AudioFilter: Modify fn modify_stream(&self, data: &mut [i16]);

src/mixer/mod.rs

@@ -1,5 +1,3 @@
-use std::borrow::Cow;
-
 use spirc::UpdateMessageSender;
 
 use self::softmixer::SoftMixer;
@@ -18,7 +16,7 @@ pub trait Mixer {
 }
 
 pub trait AudioFilter {
-  fn modify_stream<'a>(&self, data: &'a [i16]) -> Cow<'a, [i16]>;
+  fn modify_stream(&self, data: &mut [i16]);
 }
 
 pub fn find<T: AsRef<str>>(name: Option<T>) -> Option<Box<Mixer + Send>> {

src/mixer/softmixer.rs

@@ -1,4 +1,3 @@
-use std::borrow::Cow;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
@@ -48,18 +47,13 @@ struct SoftVolumeApplier {
 }
 
 impl AudioFilter for SoftVolumeApplier {
-    fn modify_stream<'a>(&self, data: &'a [i16]) -> Cow<'a, [i16]> {
+    fn modify_stream(&self, data: &mut [i16]) {
         let volume = self.volume.load(Ordering::Relaxed) as u16;
-        if volume == 0xFFFF {
-            Cow::Borrowed(data)
-        } else {
-            Cow::Owned(data.iter()
-                        .map(|&x| {
-                            (x as i32
-                                * volume as i32
-                                / 0xFFFF) as i16
-                        })
-                        .collect())
+        if volume != 0xFFFF {
+            let factor = volume as i32 / 0xFFFF;
+            for x in data.iter_mut() {
+                *x = (*x as i32 * factor) as i16;
+            }
         }
     }
 }

src/player.rs

@@ -139,10 +139,6 @@ impl Player {
     }
 }
 
-fn borrow_data<'a>(data: &'a [i16]) -> Cow<'a, [i16]> {
-    Cow::Borrowed(&data)
-}
-
 fn find_available_alternative<'a>(session: &Session, track: &'a Track) -> Option<Cow<'a, Track>> {
     if track.available {
         Some(Cow::Borrowed(track))
@@ -345,10 +341,10 @@ impl PlayerInternal {
 
                 match packet {
                     Some(Ok(packet)) => {
-                        let buffer = if let Some(ref editor) = stream_editor {
-                            editor.modify_stream(&packet.data)
-                        } else {
-                            borrow_data(&packet.data)
+                        let mut buffer = packet.data.to_vec();
+                        
+                        if let Some(ref editor) = stream_editor {
+                            editor.modify_stream(&mut buffer)
                         };
                         sink.write(&buffer).unwrap();