Add watch target for Android

[netwatcher] / src / watch_mac.rs

diff --git a/src/watch_mac.rs b/src/watch_mac.rs
index 547db4801fd2bd156e9cda7d0a0c7d37195a7650..de0e65024c27c8b912832a4775f7ac7413d38833 100644 (file)
--- a/src/watch_mac.rs
+++ b/src/watch_mac.rs
@@ -1,10 +1,89 @@
-use crate::Update;\r
-\r
-pub struct WatchHandle;\r
-\r
-pub fn watch_interfaces<F: FnMut(Update)>(callback: F) -> WatchHandle {\r
-    // stop current worker thread\r
-    // post this into a thread that will use it\r
-    drop(callback);\r
-    WatchHandle\r
-}\r
+use std::sync::Mutex;
+
+use block2::{Block, RcBlock};
+use objc2::Encoding;
+
+use crate::{Error, List, Update};
+
+// The "objc2" project aims to provide bindings for all frameworks but Network.framework
+// isn't ready yet so let's kick it old-school
+
+#[repr(C)]
+struct NwPathMonitor([u8; 0]);
+type NwPathMonitorT = *mut NwPathMonitor;
+#[repr(C)]
+struct NwPath([u8; 0]);
+#[repr(C)]
+struct DispatchQueue([u8; 0]);
+type DispatchQueueT = *mut DispatchQueue;
+const QOS_CLASS_BACKGROUND: usize = 0x09;
+
+unsafe impl objc2::Encode for NwPath {
+    const ENCODING: Encoding = usize::ENCODING;
+}
+
+#[link(name = "Network", kind = "framework")]
+extern "C" {
+    fn nw_path_monitor_create() -> NwPathMonitorT;
+    fn nw_path_monitor_set_update_handler(
+        monitor: NwPathMonitorT,
+        update_handler: &Block<dyn Fn(NwPath)>,
+    );
+    fn nw_path_monitor_set_queue(monitor: NwPathMonitorT, queue: DispatchQueueT);
+    fn nw_path_monitor_start(monitor: NwPathMonitorT);
+    fn nw_path_monitor_cancel(monitor: NwPathMonitorT);
+
+    fn dispatch_get_global_queue(identifier: usize, flag: usize) -> DispatchQueueT;
+}
+
+pub(crate) struct WatchHandle {
+    path_monitor: NwPathMonitorT,
+}
+
+impl Drop for WatchHandle {
+    fn drop(&mut self) {
+        unsafe { nw_path_monitor_cancel(self.path_monitor); }
+    }
+}
+
+struct CallbackState {
+    prev_list: List,
+    callback: Box<dyn FnMut(Update) + Send + 'static>,
+}
+
+pub(crate) fn watch_interfaces<F: FnMut(Update) + Send + 'static>(
+    callback: F,
+) -> Result<WatchHandle, Error> {
+    let state = CallbackState {
+        prev_list: List::default(),
+        callback: Box::new(callback),
+    };
+    // Blocks are Fn, not FnMut
+    let state = Mutex::new(state);
+    let block = RcBlock::new(move |_: NwPath| {
+        let mut state = state.lock().unwrap();
+        let Ok(new_list) = crate::list::list_interfaces() else {
+            return;
+        };
+        if new_list == state.prev_list {
+            return;
+        }
+        let update = Update {
+            interfaces: new_list.0.clone(),
+            diff: new_list.diff_from(&state.prev_list),
+        };
+        (state.callback)(update);
+        state.prev_list = new_list;
+    });
+    let path_monitor: NwPathMonitorT;
+    unsafe {
+        let queue = dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0);
+        path_monitor = nw_path_monitor_create();
+        nw_path_monitor_set_update_handler(path_monitor, &block);
+        nw_path_monitor_set_queue(path_monitor, queue);
+        nw_path_monitor_start(path_monitor);
+    }
+    Ok(WatchHandle {
+        path_monitor,
+    })
+}