Add Dispatcher::setup_ctrlc_handler function.

This function sets up `^C` handler which shuts down dispatching.

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - `InMemStorageError` with a single variant `DialogueNotFound` to be returned from `InMemStorage::remove_dialogue`.
  - `RedisStorageError::DialogueNotFound` and `SqliteStorageError::DialogueNotFound` to be returned from `Storage::remove_dialogue`.
  - `Dispatcher::shutdown` function.
+ - `Dispatcher::setup_ctrlc_handler` function ([issue 153](https://github.com/teloxide/teloxide/issues/153)).
 
 ### Changed
 
@@ -21,7 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Automatically delete a webhook if it was set up in `update_listeners::polling_default` (thereby making it `async`, [issue 319](https://github.com/teloxide/teloxide/issues/319)).
  - `polling` and `polling_default` now require `R: 'static`
  - Refactor `UpdateListener` trait:
-   - Add a `stop` function that allows stopping the listener.
+   - Add a `stop` function that allows stopping the listener ([issue 166](https://github.com/teloxide/teloxide/issues/166)).
    - Remove blanked implementation.
    - Remove `Stream` from super traits.
    - Add `AsUpdateStream` to super traits.

Cargo.toml

@@ -34,6 +34,8 @@ bincode-serializer = ["bincode"]
 frunk- = ["frunk"]
 macros = ["teloxide-macros"]
 
+ctrlc_handler = ["tokio/signal"]
+
 native-tls = ["teloxide-core/native-tls"]
 rustls = ["teloxide-core/rustls"]
 auto-send = ["teloxide-core/auto_send"]
@@ -51,6 +53,7 @@ full = [
     "bincode-serializer",
     "frunk",
     "macros",
+    "ctrlc_handler",
     "teloxide-core/full",
     "native-tls",
     "rustls",

src/dispatching/dispatcher.rs

@@ -75,7 +75,7 @@ pub struct Dispatcher<R> {
     my_chat_members_queue: Tx<R, ChatMemberUpdated>,
     chat_members_queue: Tx<R, ChatMemberUpdated>,
 
-    shutdown_state: AtomicShutdownState,
+    shutdown_state: Arc<AtomicShutdownState>,
     shutdown_notify_back: Notify,
 }
 
@@ -101,9 +101,9 @@ where
             poll_answers_queue: None,
             my_chat_members_queue: None,
             chat_members_queue: None,
-            shutdown_state: AtomicShutdownState {
+            shutdown_state: Arc::new(AtomicShutdownState {
                 inner: AtomicU8::new(ShutdownState::IsntRunning as _),
-            },
+            }),
             shutdown_notify_back: Notify::new(),
         }
     }
@@ -124,6 +124,25 @@ where
         Some(tx)
     }
 
+    /// Setup `^C` handler which [`shutdown`]s dispatching.
+    ///
+    /// [`shutdown`]: Dispatcher::shutdown
+    #[cfg(feature = "ctrlc_handler")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "ctrlc_handler")))]
+    pub fn setup_ctrlc_handler(self) -> Self {
+        let shutdown_state = Arc::clone(&self.shutdown_state);
+        tokio::spawn(async move {
+            loop {
+                tokio::signal::ctrl_c().await.expect("Failed to listen for ^C");
+
+                // If dispatcher wasn't running, then there is nothing to do
+                Self::shutdown_inner(&shutdown_state).ok();
+            }
+        });
+
+        self
+    }
+
     #[must_use]
     pub fn messages_handler<H>(mut self, h: H) -> Self
     where
@@ -293,6 +312,7 @@ where
                 }
 
                 if let ShuttingDown = self.shutdown_state.load() {
+                    log::debug!("Start shutting down dispatching");
                     break;
                 }
             }
@@ -310,25 +330,31 @@ where
 
             // Notify `shutdown`s that we finished
             self.shutdown_notify_back.notify_waiters();
+            log::debug!("Dispatching shut down");
+        } else {
+            log::debug!("Dispatching stopped (listner returned `None`)");
         }
 
         self.shutdown_state.store(IsntRunning);
     }
 
-    /// Tries shutting down dispatching.
+    /// Tries to shutdown dispatching.
     ///
-    /// Returns error if this dispather isn't dispathing at the moment.
+    /// Returns error if this dispather isn't dispatching at the moment.
     ///
-    /// If you don't need to wait for shutdown returned future can be ignored.
+    /// If you don't need to wait for shutdown, returned future can be ignored.
     pub fn shutdown(&self) -> Result<impl Future<Output = ()> + '_, ShutdownError> {
+        Self::shutdown_inner(&self.shutdown_state)
+            .map(|()| async move { self.shutdown_notify_back.notified().await })
+    }
+
+    fn shutdown_inner(shutdown_state: &AtomicShutdownState) -> Result<(), ShutdownError> {
         use ShutdownState::*;
 
-        let res = self.shutdown_state.compare_exchange(Running, ShuttingDown);
+        let res = shutdown_state.compare_exchange(Running, ShuttingDown);
 
         match res {
-            Ok(_) | Err(ShuttingDown) => {
+            Ok(_) | Err(ShuttingDown) => Ok(()),
-                Ok(async move { self.shutdown_notify_back.notified().await })
-            }
             Err(IsntRunning) => return Err(ShutdownError::IsntRunning),
             Err(Running) => unreachable!(),
         }

src/features.txt

@@ -9,6 +9,7 @@
 | `macros` | Re-exports macros from [`teloxide-macros`]. |
 | `native-tls` | Enables the [`native-tls`] TLS implementation (enabled by default). |
 | `rustls` | Enables the [`rustls`] TLS implementation. |
+| `ctrlc_handler` | Enables [`Dispatcher::setup_ctrlc_handler`](dispatching::Dispatcher::setup_ctrlc_handler) function. |
 | `auto-send` | Enables the `AutoSend` bot adaptor. |
 | `cache-me` | Enables the `CacheMe` bot adaptor. |
 | `frunk` | Enables [`teloxide::utils::UpState`]. |