lighty_event/
lib.rs

1// Copyright (c) 2025 Hamadi
2// Licensed under the MIT License
3
4//! Event system for LightyLauncher
5//!
6//! Simple broadcast-based event system that allows emitting events from the library
7//! and subscribing to them from user code.
8//!
9//! # Example
10//!
11//! ```no_run
12//! use lighty_event::{EventBus, Event, LaunchEvent, EventReceiveError};
13//!
14//! #[tokio::main]
15//! async fn main() {
16//!     let event_bus = EventBus::new(100);
17//!     let mut receiver = event_bus.subscribe();
18//!
19//!     // Spawn a listener with error handling
20//!     tokio::spawn(async move {
21//!         loop {
22//!             match receiver.next().await {
23//!                 Ok(event) => {
24//!                     match event {
25//!                         Event::Launch(LaunchEvent::InstallProgress { bytes }) => {
26//!                             println!("Downloaded {} bytes", bytes);
27//!                         }
28//!                         _ => {}
29//!                     }
30//!                 }
31//!                 Err(EventReceiveError::BusDropped) => {
32//!                     println!("Event bus closed");
33//!                     break;
34//!                 }
35//!                 Err(EventReceiveError::Lagged { skipped }) => {
36//!                     eprintln!("Receiver lagged, missed {} events", skipped);
37//!                 }
38//!             }
39//!         }
40//!     });
41//!
42//!     // Use the launcher with event_bus...
43//! }
44//! ```
45
46use serde::{Deserialize, Serialize};
47use tokio::sync::broadcast;
48
49// Re-export event modules
50mod errors;
51pub mod module;
52
53pub use errors::{
54    EventReceiveError, EventReceiveResult, EventSendError, EventSendResult,
55    EventTryReceiveError, EventTryReceiveResult,
56};
57pub use module::{AuthEvent, CoreEvent, JavaEvent, LaunchEvent, LoaderEvent};
58
59/// Event bus for broadcasting events to multiple listeners
60#[derive(Clone)]
61pub struct EventBus {
62    sender: broadcast::Sender<Event>,
63}
64
65impl EventBus {
66    /// Create a new EventBus with the specified buffer capacity
67    ///
68    /// # Arguments
69    /// - `capacity`: Maximum number of events to buffer. If this limit is exceeded
70    ///               and receivers are slow, the oldest events will be dropped.
71    ///
72    /// # Recommended values
73    /// - 100-1000 for most use cases
74    /// - Higher values if you have very slow receivers
75    pub fn new(capacity: usize) -> Self {
76        let (sender, _) = broadcast::channel(capacity);
77        Self { sender }
78    }
79
80    /// Subscribe to events
81    ///
82    /// Returns an EventReceiver that will receive all future events emitted
83    /// after this call.
84    pub fn subscribe(&self) -> EventReceiver {
85        EventReceiver {
86            receiver: self.sender.subscribe(),
87        }
88    }
89
90    /// Emit an event to all subscribers
91    ///
92    /// If there are no active subscribers, the event is silently dropped.
93    pub fn emit(&self, event: Event) {
94        let _ = self.sender.send(event);
95    }
96}
97
98/// Receiver for events from an EventBus
99pub struct EventReceiver {
100    receiver: broadcast::Receiver<Event>,
101}
102
103impl EventReceiver {
104    /// Wait for the next event (async blocking)
105    ///
106    /// Returns `Ok(Event)` when an event is received, or `Err(EventReceiveError)` if
107    /// the EventBus is dropped or the receiver has lagged behind.
108    ///
109    /// # Errors
110    /// - `EventReceiveError::BusDropped` - All event bus senders have been dropped
111    /// - `EventReceiveError::Lagged` - The receiver fell behind and missed some events
112    pub async fn next(&mut self) -> EventReceiveResult<Event> {
113        self.receiver.recv().await.map_err(Into::into)
114    }
115
116    /// Try to receive an event without blocking
117    ///
118    /// Returns `Ok(Event)` if an event is immediately available.
119    ///
120    /// # Errors
121    /// - `EventTryReceiveError::Empty` - No events available right now
122    /// - `EventTryReceiveError::BusDropped` - All event bus senders have been dropped
123    /// - `EventTryReceiveError::Lagged` - The receiver fell behind and missed some events
124    pub fn try_next(&mut self) -> EventTryReceiveResult<Event> {
125        self.receiver.try_recv().map_err(Into::into)
126    }
127}
128
129/// Root event enum containing all event types
130#[derive(Debug, Clone, Serialize, Deserialize)]
131#[serde(tag = "type", content = "data")]
132pub enum Event {
133    Auth(AuthEvent),
134    Java(JavaEvent),
135    Launch(LaunchEvent),
136    Loader(LoaderEvent),
137    Core(CoreEvent),
138}
lighty_event/lib.rs

lighty_event/
lib.rs
