Reuse the CGEvent between send keys

Previously, we create a new CGEvent for every keystroke, this
can be a huge waste. This commit tries to cache the events
between sends to improve the typing performance.

Lot's of unsafe stuff here but that's the trade off, i guess.

Cargo.toml

@@ -8,5 +8,8 @@ edition = "2021"
 [dependencies]
 core-foundation = "0.9.3"
 core-graphics = "0.22.3"
+env_logger = "0.10.0"
+lazy_static = "1.4.0"
 libc = "0.2.139"
+log = "0.4.17"
 vi = { git = "https://github.com/ZeroX-DG/vi-rs" }

src/main.rs

@@ -1,8 +1,8 @@
 mod platform;
 
 use std::{cmp::Ordering, sync::Mutex};
-
 use platform::{send_backspace, send_string, run_event_listener, KEY_ENTER, KEY_TAB, KEY_SPACE, KEY_ESCAPE, KEY_DELETE};
+use log::debug;
 
 static mut TYPING_BUF: Mutex<Vec<char>> = Mutex::new(vec![]);
 
@@ -25,8 +25,9 @@ fn event_handler(keycode: char, shift: bool) -> bool {
         if ['a', 'e', 'o', 'd', 's', 't', 'j', 'f', 'x', 'r', 'w'].contains(&keycode) {
             let ret = vi::telex::transform_buffer(typing_buf.as_slice());
             if ret.chars().cmp(typing_buf.clone().into_iter()) != Ordering::Equal {
-                // println!("BUF {:?} - RET {:?}", typing_buf, ret);
+                debug!("BUF {:?} - RET {:?}", typing_buf, ret);
                 let backspace_count = typing_buf.len();
+                debug!("  DEL {} - SEND {}", backspace_count, ret);
                 _ = send_backspace(backspace_count);
                 _ = send_string(&ret);
                 *typing_buf = ret.chars().collect();
@@ -38,5 +39,6 @@ fn event_handler(keycode: char, shift: bool) -> bool {
 }
 
 fn main() {
+    env_logger::init();
     run_event_listener(&event_handler);
 }

src/platform/macos.rs

@@ -1,8 +1,24 @@
 use core_foundation::runloop::{CFRunLoop, kCFRunLoopCommonModes};
 use core_graphics::{event::{EventField, CGEventTap, CGEventTapLocation, CGEventTapPlacement, CGEventTapOptions, CGEventType, KeyCode, CGKeyCode, CGEventFlags, CGEvent}, event_source::{CGEventSource, self}};
-
+use lazy_static::lazy_static;
 use super::{CallbackFn, KEY_ENTER, KEY_SPACE, KEY_TAB, KEY_DELETE, KEY_ESCAPE};
 
+struct SharedBox<T>(T);
+unsafe impl<T> Send for SharedBox<T> {}
+unsafe impl<T> Sync for SharedBox<T> {}
+impl<T> SharedBox<T> {
+    unsafe fn new(v: T) -> Self {
+        Self(v)
+    }
+}
+
+lazy_static! {
+    static ref EVENT_SOURCE: SharedBox<CGEventSource> = unsafe { SharedBox::new(CGEventSource::new(event_source::CGEventSourceStateID::Private).unwrap()) };
+    static ref BACKSPACE_DOWN: SharedBox<CGEvent> = unsafe { SharedBox::new(CGEvent::new_keyboard_event(EVENT_SOURCE.0.clone(), KeyCode::DELETE, true).unwrap()) };
+    static ref BACKSPACE_UP: SharedBox<CGEvent> = unsafe { SharedBox::new(CGEvent::new_keyboard_event(EVENT_SOURCE.0.clone(), KeyCode::DELETE, false).unwrap()) };
+    static ref SENDKEY: SharedBox<CGEvent> = unsafe { SharedBox::new(CGEvent::new_keyboard_event(EVENT_SOURCE.0.clone(), 0, true).unwrap()) };
+}
+
 // Modified from http://ritter.ist.psu.edu/projects/RUI/macosx/rui.c
 fn get_char(keycode: CGKeyCode) -> Option<char> {
     match keycode {
@@ -52,23 +68,16 @@ fn get_char(keycode: CGKeyCode) -> Option<char> {
 }
 
 pub fn send_backspace(count: usize) -> Result<(), ()> {
-    let source = CGEventSource::new(event_source::CGEventSourceStateID::Private)?;
-    let backspace_down = CGEvent::new_keyboard_event(source.clone(), KeyCode::DELETE, true)?;
-    let backspace_up = CGEvent::new_keyboard_event(source.clone(), KeyCode::DELETE, false)?;
-
     for _ in 0..count {
-        backspace_down.post(CGEventTapLocation::HID);
-        backspace_up.post(CGEventTapLocation::HID);
+        BACKSPACE_DOWN.0.post(CGEventTapLocation::HID);
+        BACKSPACE_UP.0.post(CGEventTapLocation::HID);
     }
-
     Ok(())
 }
 
 pub fn send_string(string: &str) -> Result<(), ()> {
-    let source = CGEventSource::new(event_source::CGEventSourceStateID::Private)?;
-    let event = CGEvent::new_keyboard_event(source, 0, true)?;
-    event.set_string(string);
-    event.post(CGEventTapLocation::HID);
+    SENDKEY.0.set_string(string);
+    SENDKEY.0.post(CGEventTapLocation::HID);
     Ok(())
 }