Remove path and duration from the decoded song

src/song.rs

@@ -33,11 +33,9 @@ use ndarray::{arr1, Array1};
 use std::convert::TryInto;
 use std::fmt;
 use std::path::Path;
-use std::path::PathBuf;
 use std::sync::mpsc;
 use std::sync::mpsc::Receiver;
 use std::thread as std_thread;
-use std::time::Duration;
 use strum::{EnumCount, IntoEnumIterator};
 use strum_macros::{EnumCount, EnumIter};
 
@@ -46,12 +44,8 @@ use strum_macros::{EnumCount, EnumIter};
 /// Simple object used to represent a Song, with its path, analysis, and
 /// other metadata (artist, genre...)
 pub struct Song {
-    /// Song's provided file path
-    pub path: PathBuf,
     /// bliss analysis results
     pub analysis: Analysis,
-    /// The song's duration
-    pub duration: Duration,
     /// Version of the features the song was analyzed with.
     /// A simple integer that is bumped every time a breaking change
     /// is introduced in the features.
@@ -215,12 +209,10 @@ impl Song {
     /// decoding ([DecodingError](BlissError::DecodingError)) or an analysis
     /// ([AnalysisError](BlissError::AnalysisError)) error.
     pub fn from_path<P: AsRef<Path>>(path: P) -> BlissResult<Self> {
-        let raw_song = Song::decode(path.as_ref())?;
+        let samples = Song::decode(path.as_ref())?;
 
         Ok(Song {
-            path: raw_song.path,
-            duration: raw_song.duration,
-            analysis: Song::analyze(&raw_song.sample_array)?,
+            analysis: Song::analyze(&samples)?,
             features_version: FEATURES_VERSION,
         })
     }
@@ -348,7 +340,7 @@ impl Song {
         .unwrap()
     }
 
-    pub(crate) fn decode(path: &Path) -> BlissResult<InternalSong> {
+    pub(crate) fn decode(path: &Path) -> BlissResult<Vec<f32>> {
         ffmpeg::init().map_err(|e| {
             BlissError::DecodingError(format!(
                 "ffmpeg init error while decoding file '{}': {:?}.",
@@ -357,10 +349,7 @@ impl Song {
             ))
         })?;
         log::set_level(Level::Quiet);
-        let mut song = InternalSong {
-            path: path.into(),
-            ..Default::default()
-        };
+
         let mut ictx = ffmpeg::format::input(&path).map_err(|e| {
             BlissError::DecodingError(format!(
                 "while opening format for file '{}': {:?}.",
@@ -451,8 +440,7 @@ impl Song {
                         path.display()
                     );
                     drop(tx);
-                    song.sample_array = child.join().unwrap()?;
-                    return Ok(song);
+                    return Ok(child.join().unwrap()?);
                 }
                 Err(e) => warn!("error while decoding file '{}': {}", path.display(), e),
             };
@@ -490,8 +478,7 @@ impl Song {
                     path.display()
                 );
                 drop(tx);
-                song.sample_array = child.join().unwrap()?;
-                return Ok(song);
+                return Ok(child.join().unwrap()?);
             }
             Err(e) => warn!("error while decoding {}: {}", path.display(), e),
         };
@@ -513,20 +500,10 @@ impl Song {
         }
 
         drop(tx);
-        song.sample_array = child.join().unwrap()?;
-        let duration_seconds = song.sample_array.len() as f32 / SAMPLE_RATE as f32;
-        song.duration = Duration::from_nanos((duration_seconds * 1e9_f32).round() as u64);
-        Ok(song)
+        Ok(child.join().unwrap()?)
     }
 }
 
-#[derive(Default, Debug)]
-pub(crate) struct InternalSong {
-    pub path: PathBuf,
-    pub duration: Duration,
-    pub sample_array: Vec<f32>,
-}
-
 fn resample_frame(
     rx: Receiver<Audio>,
     in_codec_format: Sample,
@@ -672,9 +649,9 @@ mod tests {
     }
 
     fn _test_decode(path: &Path, expected_hash: &[u8]) {
-        let song = Song::decode(path).unwrap();
+        let samples = Song::decode(path).unwrap();
         let mut hasher = Ripemd160::new();
-        for sample in song.sample_array.iter() {
+        for sample in samples.iter() {
             hasher.update(sample.to_le_bytes().to_vec());
         }
 
@@ -736,26 +713,23 @@ mod tests {
     #[test]
     fn test_decode_right_capacity_vec() {
         let path = Path::new("data/s16_mono_22_5kHz.flac");
-        let song = Song::decode(&path).unwrap();
-        let sample_array = song.sample_array;
+        let samples = Song::decode(&path).unwrap();
         assert_eq!(
-            sample_array.len() + SAMPLE_RATE as usize,
-            sample_array.capacity()
+            samples.len() + SAMPLE_RATE as usize,
+            samples.capacity()
         );
 
         let path = Path::new("data/s32_stereo_44_1_kHz.flac");
-        let song = Song::decode(&path).unwrap();
-        let sample_array = song.sample_array;
+        let samples = Song::decode(&path).unwrap();
         assert_eq!(
-            sample_array.len() + SAMPLE_RATE as usize,
-            sample_array.capacity()
+            samples.len() + SAMPLE_RATE as usize,
+            samples.capacity()
         );
 
         let path = Path::new("data/capacity_fix.ogg");
-        let song = Song::decode(&path).unwrap();
-        let sample_array = song.sample_array;
-        assert!(sample_array.len() as f32 / sample_array.capacity() as f32 > 0.90);
-        assert!(sample_array.len() as f32 / (sample_array.capacity() as f32) < 1.);
+        let samples = Song::decode(&path).unwrap();
+        assert!(samples.len() as f32 / samples.capacity() as f32 > 0.90);
+        assert!(samples.len() as f32 / (samples.capacity() as f32) < 1.);
     }
 
     #[test]