fix: remove missing resource path from tauri.conf; add GPU detection and layer clamping

tauri-app/src-tauri/src/lib.rs

@@ -4,6 +4,57 @@ use tauri::{Manager, State};
 
 pub struct ServerState(pub Mutex<Option<Child>>);
 
+/// Query GPU info via nvidia-smi.
+/// Returns (gpu_name, vram_mib, recommended_layers).
+/// recommended_layers is estimated as vram_mib / 80 (rough heuristic for 4-bit quant).
+#[tauri::command]
+fn query_gpu() -> Result<GpuInfo, String> {
+    let output = Command::new("nvidia-smi")
+        .args([
+            "--query-gpu=name,memory.total",
+            "--format=csv,noheader,nounits",
+        ])
+        .output()
+        .map_err(|_| "nvidia-smi not found — no NVIDIA GPU detected".to_string())?;
+
+    if !output.status.success() {
+        return Err("nvidia-smi failed — no NVIDIA GPU detected".into());
+    }
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let line = stdout.lines().next().unwrap_or("").trim().to_string();
+    if line.is_empty() {
+        return Err("No GPU found".into());
+    }
+
+    // Format: "GPU Name, 8192"
+    let parts: Vec<&str> = line.splitn(2, ',').collect();
+    if parts.len() < 2 {
+        return Err(format!("Unexpected nvidia-smi output: {line}"));
+    }
+
+    let name = parts[0].trim().to_string();
+    let vram_mib: u32 = parts[1].trim().parse().unwrap_or(0);
+
+    // Heuristic: ~80 MiB per layer for Q4/Q6 models (conservative)
+    // Reserve 1 GiB for OS/other usage
+    let usable = vram_mib.saturating_sub(1024);
+    let recommended_layers = (usable / 80).min(200) as i32;
+
+    Ok(GpuInfo {
+        name,
+        vram_mib,
+        recommended_layers,
+    })
+}
+
+#[derive(serde::Serialize)]
+pub struct GpuInfo {
+    pub name: String,
+    pub vram_mib: u32,
+    pub recommended_layers: i32,
+}
+
 #[tauri::command]
 fn start_server(
     state: State<ServerState>,
@@ -17,7 +68,6 @@ fn start_server(
         return Err("Server is already running".into());
     }
 
-    // Resolve binary path relative to the app's resource dir or PATH
     let binary = if cfg!(target_os = "windows") {
         "localllm.exe"
     } else {
@@ -70,6 +120,7 @@ pub fn run() {
         .plugin(tauri_plugin_shell::init())
         .manage(ServerState(Mutex::new(None)))
         .invoke_handler(tauri::generate_handler![
+            query_gpu,
             start_server,
             stop_server,
             server_status