Add UnknownBufferType::len()

src/alsa/mod.rs

@@ -125,6 +125,10 @@ impl<'a, T> Buffer<'a, T> {
         &mut self.buffer
     }
 
+    pub fn len(&self) -> usize {
+        self.buffer.len()
+    }
+
     pub fn finish(self) {
         let written = (self.buffer.len() / self.channel.num_channels as usize)
                       as alsa::snd_pcm_uframes_t;

src/lib.rs

@@ -181,6 +181,17 @@ pub enum UnknownTypeBuffer<'a> {
     F32(Buffer<'a, f32>),
 }
 
+impl<'a> UnknownTypeBuffer<'a> {
+    /// Returns the length of the buffer in number of samples.
+    pub fn len(&self) -> usize {
+        match self {
+            &UnknownTypeBuffer::U16(ref buf) => buf.target.as_ref().unwrap().len(),
+            &UnknownTypeBuffer::I16(ref buf) => buf.target.as_ref().unwrap().len(),
+            &UnknownTypeBuffer::F32(ref buf) => buf.target.as_ref().unwrap().len(),
+        }
+    }
+}
+
 /// Error that can happen when enumerating the list of supported formats.
 #[derive(Debug)]
 pub enum FormatsEnumerationError {

src/null/mod.rs

@@ -81,6 +81,10 @@ impl<'a, T> Buffer<'a, T> {
         unreachable!()
     }
 
+    pub fn len(&self) -> usize {
+        0
+    }
+
     pub fn finish(self) {
     }
 }

src/wasapi/voice.rs

@@ -322,6 +322,10 @@ impl<'a, T> Buffer<'a, T> {
         }
     }
 
+    pub fn len(&self) -> usize {
+        self.buffer_len
+    }
+
     pub fn finish(self) {
         // releasing buffer
         unsafe {