Refactor {first,last}_audio_byte()

src/metadata/metadata.rs

@@ -55,6 +55,35 @@ impl NrgMetadata {
             skipped_chunks: Vec::new(),
         }
     }
+
+    /// Returns the index1 of the first DAOX track in `metadata`, or 0 if there
+    /// are no DAOX tracks.
+    pub fn first_audio_byte(&self) -> u64 {
+        if let Some(daox_chunk) = self.daox_chunk.as_ref() {
+            if let Some(first_track) = daox_chunk.tracks.first() {
+                return first_track.index1;
+            }
+        }
+        0
+    }
+
+    /// Returns the number of the byte past the last audio byte in the image
+    /// (i.e. `last audio byte + 1`).
+    ///
+    /// This byte is indicated by the `track_end` of the last DAOX track if at
+    /// least one track is present in the DAOX chunk. If not, `chunk_offset` is
+    /// returned.
+    ///
+    /// Note that the two values should always be identical anyway, but you
+    /// never know.
+    pub fn last_audio_byte(&self) -> u64 {
+        if let Some(daox_chunk) = self.daox_chunk.as_ref() {
+            if let Some(last_track) = daox_chunk.tracks.last() {
+                return last_track.track_end;
+            }
+        }
+        self.chunk_offset
+    }
 }
 
 impl fmt::Display for NrgMetadata {

src/raw_audio.rs

@@ -44,11 +44,11 @@ pub fn extract_nrg_raw_audio(in_fd: &mut File,
     const BUF_SIZE: usize = 1024 * 1024 * 4; // 4 MiB
 
     // Seek to the first audio byte
-    let first_audio_byte = get_daox_track1_index1(metadata);
+    let first_audio_byte = metadata.first_audio_byte();
     try!(in_fd.seek(SeekFrom::Start(first_audio_byte)));
 
     // Get the last audio byte
-    let last_audio_byte = get_last_audio_byte(metadata);
+    let last_audio_byte = metadata.last_audio_byte();
 
     // Open output file
     let audio_name = try!(make_output_file_name(img_path));
@@ -89,37 +89,6 @@ pub fn extract_nrg_raw_audio(in_fd: &mut File,
 }
 
 
-/// Returns the index1 of the first DAOX track in `metadata`, or 0 if there are
-/// no DAOX tracks.
-fn get_daox_track1_index1(metadata: &NrgMetadata) -> u64 {
-    if metadata.daox_chunk.is_none() {
-        return 0;
-    }
-    let daox_tracks = &metadata.daox_chunk.as_ref().unwrap().tracks;
-    if daox_tracks.is_empty() {
-        return 0;
-    }
-    return daox_tracks[0].index1;
-}
-
-
-/// Returns the number of the byte past the last audio byte in the image.
-///
-/// This byte is indicated by the `track_end` of the last DAOX track in
-/// `metadata`, if at least one track is present in the DAOX chunk.
-/// If not, `metadata.chunk_offset` is returned.
-///
-/// Note that the two values should always be identical, but you never know.
-fn get_last_audio_byte(metadata: &NrgMetadata) -> u64 {
-    if let Some(daox_chunk) = metadata.daox_chunk.as_ref() {
-        if let Some(last_track) = daox_chunk.tracks.last() {
-            return last_track.track_end;
-        }
-    }
-    metadata.chunk_offset
-}
-
-
 /// Generates the output file's name from the NRG image's name.
 ///
 /// The output file's name will be `img_path`'s base name stripped for its