Optimize typing performance and preserve casing on replaced syllables

daemon/src/main.rs

@@ -448,6 +448,7 @@ fn run_with_evdev(
             return Ok(());
         }
 
+        let caps = is_caps_lock_on(&device);
         let key_state = device.get_key_state().ok();
         let events = device.fetch_events()?;
         last_event_time = std::time::Instant::now();
@@ -530,7 +531,13 @@ fn run_with_evdev(
                         if consumed_keys.contains(&keycode) {
                             consumed_keys.remove(&keycode);
                         }
-                        if let Some(ch) = key_to_char(key) {
+                        if let Some(mut ch) = key_to_char(key) {
+                            let shift = is_modifier_held_shift(&key_state);
+                            if ch.is_ascii_alphabetic() {
+                                if shift ^ caps {
+                                    ch = ch.to_ascii_uppercase();
+                                }
+                            }
                             let commands = daemon.process_key(ch);
                             if !commands.is_empty() {
                                 consumed_keys.insert(keycode);
@@ -745,6 +752,22 @@ fn is_modifier_pressed(key_state: &Option<evdev::AttributeSet<evdev::Key>>) -> b
         || key_state.contains(evdev::Key::KEY_RIGHTMETA)
 }
 
+fn is_modifier_held_shift(key_state: &Option<evdev::AttributeSet<evdev::Key>>) -> bool {
+    let ks = match key_state {
+        Some(ks) => ks,
+        None => return false,
+    };
+    ks.contains(evdev::Key::KEY_LEFTSHIFT) || ks.contains(evdev::Key::KEY_RIGHTSHIFT)
+}
+
+fn is_caps_lock_on(device: &evdev::Device) -> bool {
+    if let Ok(leds) = device.get_led_state() {
+        leds.contains(evdev::LedType::LED_CAPSL)
+    } else {
+        false
+    }
+}
+
 fn is_toggle_combination_state(key_state: &Option<evdev::AttributeSet<evdev::Key>>, key: &str) -> bool {
     let key_state = match key_state {
         Some(ks) => ks,

engine/src/engine.rs

@@ -64,9 +64,16 @@ impl Engine {
     }
 
     pub fn flush(&mut self) -> Option<EngineEvent> {
-        match self.input_method {
+        let event = match self.input_method {
             InputMethod::Telex => self.telex.flush(),
             InputMethod::Vni => self.vni.flush(),
+        };
+        if let Some(EngineEvent::Flush(word)) = event {
+            let cased = match_casing(&self.raw_buffer, &word);
+            self.raw_buffer.clear();
+            Some(EngineEvent::Flush(cased))
+        } else {
+            event
         }
     }
 
@@ -95,15 +102,16 @@ impl Engine {
         let stripped = strip_diacritics(buffer);
         let backspaces = buffer.chars().count();
         let had_tones = stripped != buffer;
+        let cased_stripped = match_casing(&self.raw_buffer, &stripped);
         self.reset();
 
         if had_tones {
             Some(EngineEvent::UndoTones {
                 backspaces,
-                restored: stripped,
+                restored: cased_stripped,
             })
         } else {
-            Some(EngineEvent::Flush(stripped))
+            Some(EngineEvent::Flush(cased_stripped))
         }
     }
 
@@ -137,15 +145,21 @@ impl Engine {
             return None;
         }
 
-        if ch == ' ' || ch == '\t' || ch == '.' || ch == ',' || ch == '!' || ch == '?'
+        let lowercase_ch = if ch.is_ascii() {
-            || ch == ';' || ch == ':' || ch == '\n'
+            ch.to_ascii_lowercase()
+        } else {
+            ch.to_lowercase().next().unwrap_or(ch)
+        };
+
+        if lowercase_ch == ' ' || lowercase_ch == '\t' || lowercase_ch == '.' || lowercase_ch == ',' || lowercase_ch == '!' || lowercase_ch == '?'
+            || lowercase_ch == ';' || lowercase_ch == ':' || lowercase_ch == '\n'
         {
             if self.raw_buffer.is_empty() {
                 return None;
             }
 
             // Check for macro expansion before auto-restore
-            let macro_expansion = self.macros.get(&self.raw_buffer).cloned();
+            let macro_expansion = self.macros.get(&self.raw_buffer.to_lowercase()).cloned();
             if let Some(expansion) = macro_expansion {
                 let previous_raw_len = self.raw_buffer.chars().count();
                 self.reset();
@@ -180,13 +194,14 @@ impl Engine {
             let previous_inner = self.buffer().to_string();
             let previous_inner_len = previous_inner.chars().count();
             
+            let previous_inner_cased = match_casing(&self.raw_buffer, &previous_inner);
             let flush_event = self.flush();
-            let mut final_word = previous_inner.clone();
+            let mut final_word = previous_inner_cased.clone();
             if let Some(EngineEvent::Flush(word)) = flush_event {
                 final_word = word;
             }
 
-            let result = if final_word != previous_inner {
+            let result = if final_word != previous_inner_cased {
                 Some(EngineEvent::Replace {
                     backspaces: previous_inner_len + 1,
                     insert: format!("{}{}", final_word, ch),
@@ -204,17 +219,18 @@ impl Engine {
         self.raw_buffer.push(ch);
 
         match self.input_method {
-            InputMethod::Telex => { self.telex.process_key(ch); }
+            InputMethod::Telex => { self.telex.process_key(lowercase_ch); }
-            InputMethod::Vni => { self.vni.process_key(ch); }
+            InputMethod::Vni => { self.vni.process_key(lowercase_ch); }
         }
 
         let new_inner = self.buffer().to_string();
-        let expected_screen = format!("{}{}", previous_inner, ch);
+        let expected_screen = format!("{}{}", previous_inner, lowercase_ch);
 
         if new_inner != expected_screen {
+            let cased_inner = match_casing(&self.raw_buffer, &new_inner);
             Some(EngineEvent::Replace {
                 backspaces: previous_inner.chars().count() + 1,
-                insert: new_inner,
+                insert: cased_inner,
             })
         } else {
             None
@@ -265,6 +281,32 @@ fn strip_diacritics(s: &str) -> String {
         .collect()
 }
 
+fn match_casing(raw: &str, processed: &str) -> String {
+    if raw.is_empty() || processed.is_empty() {
+        return processed.to_string();
+    }
+
+    let alphabetic_chars: Vec<char> = raw.chars().filter(|c| c.is_alphabetic()).collect();
+    if alphabetic_chars.is_empty() {
+        return processed.to_string();
+    }
+
+    let all_upper = alphabetic_chars.iter().all(|c| c.is_uppercase());
+    let first_upper = alphabetic_chars[0].is_uppercase();
+
+    if all_upper {
+        processed.to_uppercase()
+    } else if first_upper {
+        let mut chars = processed.chars();
+        match chars.next() {
+            Some(first) => first.to_uppercase().collect::<String>() + chars.as_str(),
+            None => processed.to_string(),
+        }
+    } else {
+        processed.to_string()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -318,4 +360,41 @@ mod tests {
 
         assert!(output.contains("không"));
     }
+
+    #[test]
+    fn test_casing_preservation() {
+        let mut engine = Engine::new(InputMethod::Telex);
+
+        // Lowercase: "sats" -> "sát"
+        engine.reset();
+        let _ = engine.process_key('s');
+        let _ = engine.process_key('a');
+        let _ = engine.process_key('t');
+        let _ = engine.process_key('s');
+        assert_eq!(engine.buffer(), "sát");
+
+        // Titlecase: "Sats" -> "Sát"
+        engine.reset();
+        engine.process_key('S');
+        engine.process_key('a');
+        engine.process_key('t');
+        let event = engine.process_key('s');
+        if let Some(EngineEvent::Replace { insert, .. }) = event {
+            assert_eq!(insert, "Sát");
+        } else {
+            panic!("Expected Replace event, got {:?}", event);
+        }
+
+        // Uppercase: "SATS" -> "SÁT"
+        engine.reset();
+        engine.process_key('S');
+        engine.process_key('A');
+        engine.process_key('T');
+        let event2 = engine.process_key('S');
+        if let Some(EngineEvent::Replace { insert, .. }) = event2 {
+            assert_eq!(insert, "SÁT");
+        } else {
+            panic!("Expected Replace event, got {:?}", event2);
+        }
+    }
 }

protocol/src/uinput_monitor.rs

@@ -171,6 +171,7 @@ impl UinputInjector {
 
         if let Ok(content) = std::fs::read_to_string("/proc/self/loginuid") {
             if let Ok(uid) = content.trim().parse::<u32>() {
+                if uid != 4294967295 {
                     unsafe {
                         let pw = libc::getpwuid(uid);
                         if !pw.is_null() {
@@ -183,6 +184,7 @@ impl UinputInjector {
                     }
                 }
             }
+        }
 
         if let Ok(output) = std::process::Command::new("logname").output() {
             if output.status.success() {
@@ -196,34 +198,84 @@ impl UinputInjector {
         None
     }
 
+    /// Get original non-root UID and GID when running as root.
+    fn get_original_uid_gid() -> Option<(u32, u32)> {
+        let is_root = unsafe { libc::getuid() == 0 };
+        if !is_root {
+            return None;
+        }
+
+        let mut target_uid = None;
+
+        if let Ok(uid_str) = std::env::var("SUDO_UID") {
+            if let Ok(uid) = uid_str.parse::<u32>() {
+                target_uid = Some(uid);
+            }
+        }
+
+        if target_uid.is_none() {
+            if let Ok(uid_str) = std::env::var("PKEXEC_UID") {
+                if let Ok(uid) = uid_str.parse::<u32>() {
+                    target_uid = Some(uid);
+                }
+            }
+        }
+
+        if target_uid.is_none() {
+            if let Ok(content) = std::fs::read_to_string("/proc/self/loginuid") {
+                if let Ok(uid) = content.trim().parse::<u32>() {
+                    if uid != 4294967295 {
+                        target_uid = Some(uid);
+                    }
+                }
+            }
+        }
+
+        if let Some(uid) = target_uid {
+            unsafe {
+                let pw = libc::getpwuid(uid);
+                if !pw.is_null() {
+                    let gid = (*pw).pw_gid;
+                    return Some((uid, gid));
+                }
+            }
+        }
+
+        None
+    }
+
     /// Run an external command as the original user if we're root.
-    /// Wayland tools (wtype, wl-copy) need the user's session, not root.
+    /// Uses native OS setuid/setgid to avoid slow PAM/logging/sudo startup overhead.
-    /// Uses explicit `env VAR=val` instead of `--preserve-env` for
-    /// compatibility with all sudo versions.
     fn run_as_user(program: &str, args: &[&str]) -> std::process::Output {
         let is_root = unsafe { libc::getuid() == 0 };
         if is_root {
-            if let Some(original_user) = Self::get_original_username() {
+            if let Some((uid, gid)) = Self::get_original_uid_gid() {
                 let wayland_display = std::env::var("WAYLAND_DISPLAY").unwrap_or_default();
                 let xdg_runtime_dir = std::env::var("XDG_RUNTIME_DIR").unwrap_or_default();
                 let display = std::env::var("DISPLAY").unwrap_or_default();
-                let mut cmd = std::process::Command::new("sudo");
+                
-                cmd.args(["-u", &original_user, "env"]);
+                use std::os::unix::process::CommandExt;
+                let mut cmd = std::process::Command::new(program);
+                cmd.uid(uid).gid(gid);
+                
                 if !wayland_display.is_empty() {
-                    cmd.arg(format!("WAYLAND_DISPLAY={}", wayland_display));
+                    cmd.env("WAYLAND_DISPLAY", wayland_display);
                 }
                 if !xdg_runtime_dir.is_empty() {
-                    cmd.arg(format!("XDG_RUNTIME_DIR={}", xdg_runtime_dir));
+                    cmd.env("XDG_RUNTIME_DIR", xdg_runtime_dir);
                 }
                 if !display.is_empty() {
-                    cmd.arg(format!("DISPLAY={}", display));
+                    cmd.env("DISPLAY", display);
                 }
-                cmd.arg(program);
+                if let Some(username) = Self::get_original_username() {
+                    cmd.env("HOME", format!("/home/{}", username));
+                }
+                
                 cmd.args(args);
                 match cmd.output() {
                     Ok(output) => return output,
                     Err(e) => {
-                        eprintln!("[vietc] Failed to run sudo -u {} env ... {} {}: {}", original_user, program, args.join(" "), e);
+                        eprintln!("[vietc] Failed to run {} as uid={}: {}", program, uid, e);
                         return std::process::Output {
                             status: std::process::ExitStatus::default(),
                             stdout: vec![],
@@ -231,8 +283,6 @@ impl UinputInjector {
                         };
                     }
                 }
-            } else {
-                eprintln!("[vietc] Running as root but could not determine original user");
             }
         }
         match std::process::Command::new(program).args(args).output() {
@@ -271,13 +321,17 @@ impl UinputInjector {
         // It is Unicode. We must use a single unified channel.
         let is_wayland = std::env::var("WAYLAND_DISPLAY").is_ok();
         
+        static HAS_WTYPE: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
+        static HAS_XDOTOOL: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
+
         if is_wayland {
-            // Under Wayland, we try to use `wtype` for both backspaces and text.
+            let has_wtype = *HAS_WTYPE.get_or_init(|| {
-            let has_wtype = std::process::Command::new("which")
+                std::process::Command::new("which")
                     .arg("wtype")
                     .output()
                     .map(|o| o.status.success())
-                .unwrap_or(false);
+                    .unwrap_or(false)
+            });
                 
             if has_wtype {
                 let mut args = Vec::new();
@@ -295,12 +349,13 @@ impl UinputInjector {
                 eprintln!("[vietc] wtype inject failed: {}", String::from_utf8_lossy(&output.stderr).trim());
             }
         } else {
-            // Under X11, we try to use `xdotool` for both backspaces and text.
+            let has_xdotool = *HAS_XDOTOOL.get_or_init(|| {
-            let has_xdotool = std::process::Command::new("which")
+                std::process::Command::new("which")
                     .arg("xdotool")
                     .output()
                     .map(|o| o.status.success())
-                .unwrap_or(false);
+                    .unwrap_or(false)
+            });
                 
             if has_xdotool {
                 let mut args = Vec::new();