Add MIN_ITER_DUR env var, add configuration to README.md

README.md

@@ -32,3 +32,29 @@ Just run the program (if installed through Cargo, enter
 `apple-music-rich-presence` into your terminal) and you're good to go! I would
 recommend adding it to your Login Items in System Settings so that you don't
 have to start it manually every time you restart your computer.
+
+### Configuration
+
+There are a few environment variables that can be used to configure Apple Music
+Rich Presence.
+
+#### `MIN_ITER_DUR`
+
+Apple Music Rich Presence, by default, will ensure that each iteration (where it
+checks whether Discord and Apple Music are open, whether the currently playing
+song has changed, etc.) spans at least 1 second. If you feel that it need more
+time to prevent glitchy behaviour like Apple Music refusing to quit, you can
+raise this to, say, `MIN_ITER_DUR=3`.
+
+#### `DAEMON`
+
+By default, Apple Music Rich Presence will launch a daemon process to run in the
+background. You can disable this behaviour, however, by setting `DAEMON` to `0`.
+Then, the program will stay present and you'll be able to see its logging in
+your terminal.
+
+#### `RUST_LOG`
+
+This variable configures the level of logging to perform. See
+[`env_logger`'s documentation](https://docs.rs/env_logger/latest/env_logger/#enabling-logging)
+for info.

src/main.rs

@@ -33,7 +33,6 @@ use log::{debug, error, info, trace, warn};
 use sysinfo::{ProcessRefreshKind, ProcessesToUpdate};
 
 const CLIENT_ID: &str = "1273805325954187386";
-const LOOP_DURATION: Duration = Duration::from_secs(1);
 const EXPECT_CLIENT_INITIALIZED: &str = "Discord client has not been initialized";
 
 fn inner_loop(
@@ -200,6 +199,12 @@ fn try_main() -> Result<(), Box<dyn Error>> {
         debug!("Daemonized");
     }
 
+    let min_iter_dur = Duration::from_secs(
+        env::var("MIN_ITER_DUR")
+            .unwrap_or("1".to_string())
+            .parse()
+            .map_err(|err| format!("Failed to parse `MIN_ITER_DUR`: {err}"))?,
+    );
     let mut sys = sysinfo::System::new();
     let mut discord_client_option = None;
     let mut last_track = None;
@@ -219,8 +224,8 @@ fn try_main() -> Result<(), Box<dyn Error>> {
 
         let loop_start_elapsed = loop_start.elapsed();
 
-        if loop_start_elapsed < LOOP_DURATION {
-            sleep(LOOP_DURATION - loop_start_elapsed);
+        if loop_start_elapsed < min_iter_dur {
+            sleep(min_iter_dur - loop_start_elapsed);
         }
     }
 }