move image decoding to blocking task

src/subsonic.rs

@@ -294,13 +294,19 @@ impl Client {
             };
             return error;
         }
-        let image = ImageReader::new(std::io::BufReader::new(std::io::Cursor::new(
+        // decoding the image can take up a good chunk of cpu time, so spawn a blocking task
+        let image = runtime()
+            .spawn_blocking(move || {
+                ImageReader::new(std::io::BufReader::new(std::io::Cursor::new(
                     byteresponse.bytes,
                 )))
                 .with_guessed_format()
                 .map_err(|e| Error::ImageDecodeError(image::ImageError::IoError(e)))?
                 .decode()
-        .map_err(Error::ImageDecodeError)?;
+                .map_err(Error::ImageDecodeError)
+            })
+            .await
+            .expect("could not receive image from blocking tokio task")?;
 
         let width = image.width();
         let height = image.height();