ALSA: hardcode builtins virtual devices

Author: abique

src/host/alsa/enumerate.rs

@@ -5,12 +5,14 @@ use std::sync::{Arc, Mutex};
 
 /// ALSA's implementation for `Devices`.
 pub struct Devices {
+    builtin_pos: usize,
     card_iter: alsa::card::Iter,
 }
 
 impl Devices {
     pub fn new() -> Result<Self, DevicesError> {
         Ok(Devices {
+            builtin_pos: 0,
             card_iter: alsa::card::Iter::new(),
         })
     }
@@ -19,10 +21,27 @@ impl Devices {
 unsafe impl Send for Devices {}
 unsafe impl Sync for Devices {}
 
+const BUILTINS : [&'static str; 5] = ["default", "pipewire", "pulse", "jack", "oss"];
+
 impl Iterator for Devices {
     type Item = Device;
 
     fn next(&mut self) -> Option<Device> {
+        while (self.builtin_pos < BUILTINS.len())
+        {
+            let pos = self.builtin_pos;
+            self.builtin_pos += 1;
+            let name = BUILTINS[pos];
+
+            if let Ok(handles) = DeviceHandles::open(&name) {
+                return Some(Device {
+                    name: name.to_string(),
+                    pcm_id: name.to_string(),
+                    handles: Arc::new(Mutex::new(handles)),
+                });
+            }
+        }
+
         loop {
             let Some(res) = self.card_iter.next() else {
                 return None;