Make example program test dropping the WatchHandle

[netwatcher] / src / lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 69de586c46db24fc7cf395107661093d569ed2f5..495b9e64f5098aadb9b1d7d8b8d7f4a4603f2a40 100644 (file)
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,17 +4,24 @@ use std::{
     ops::Sub,
 };
 
+mod error;
+
 #[cfg_attr(windows, path = "list_win.rs")]
 #[cfg_attr(unix, path = "list_unix.rs")]
 mod list;
 
 #[cfg_attr(windows, path = "watch_win.rs")]
 #[cfg_attr(target_vendor = "apple", path = "watch_mac.rs")]
-#[cfg_attr(target_os = "linux", path = "watch_linux.rs")]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    path = "watch_linux.rs"
+)]
 mod watch;
 
 type IfIndex = u32;
 
+pub use error::Error;
+
 /// Information about one network interface at a point in time.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Interface {
@@ -43,7 +50,7 @@ impl Interface {
 }
 
 /// Information delivered via callback when a network interface change is detected.
-/// 
+///
 /// This contains up-to-date information about all interfaces, plus a diff which
 /// details which interfaces and IP addresses have changed since the last callback.
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -68,13 +75,6 @@ pub struct InterfaceDiff {
     pub addrs_removed: Vec<IpAddr>,
 }
 
-/// Errors in netwatcher or in one of the underlying platform integratinos.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum Error {
-    // TODO: handle all cases with proper sources
-    Internal,
-}
-
 #[derive(Default, PartialEq, Eq)]
 struct List(HashMap<IfIndex, Interface>);
 
@@ -122,29 +122,38 @@ impl List {
 }
 
 /// A handle to keep alive as long as you wish to receive callbacks.
-/// 
+///
 /// If the callback is executing at the time the handle is dropped, drop will block until
 /// the callback is finished and it's guaranteed that it will not be called again.
-/// 
+///
 /// Do not drop the handle from within the callback itself. It will probably deadlock.
 pub struct WatchHandle {
     _inner: watch::WatchHandle,
 }
 
 /// Retrieve information about all enabled network interfaces and their IP addresses.
-/// 
+///
 /// This is a once-off operation. If you want to detect changes over time, see `watch_interfaces`.
 pub fn list_interfaces() -> Result<HashMap<IfIndex, Interface>, Error> {
     list::list_interfaces().map(|list| list.0)
 }
 
 /// Retrieve interface information and watch for changes, which will be delivered via callback.
-/// 
+///
 /// If setting up the watch is successful, this returns a `WatchHandle` which must be kept for
 /// as long as the provided callback should operate.
-/// 
+///
 /// The callback will fire once immediately with an initial interface list, and a diff as if
 /// there were originally no interfaces present.
-pub fn watch_interfaces<F: FnMut(Update) + Send + 'static>(callback: F) -> Result<WatchHandle, Error> {
+///
+/// This function will return an error if there is a problem configuring the watcher, or if there
+/// is an error retrieving the initial interface list.
+///
+/// We assume that if listing the interfaces worked the first time, then it will continue to work
+/// for as long as the watcher is running. If listing interfaces begins to fail later, those
+/// failures will be swallowed and the callback will not be called for that change event.
+pub fn watch_interfaces<F: FnMut(Update) + Send + 'static>(
+    callback: F,
+) -> Result<WatchHandle, Error> {
     watch::watch_interfaces(callback).map(|handle| WatchHandle { _inner: handle })
 }