Desktop: Run CEF in incognito mode and delete root cache path on exit (#3137)

* Try

* Run cef in non persistence mode

Author: timon-schelling

Cargo.lock

@@ -41,6 +41,7 @@ vello = { workspace = true }
 derivative = { workspace = true }
 rfd = { workspace = true }
 open = { workspace = true }
+rand = { workspace = true }
 serde = { workspace = true }
 
 # Hardware acceleration dependencies

desktop/Cargo.toml

@@ -1,16 +1,19 @@
+use std::path::PathBuf;
+
 use cef::args::Args;
 use cef::sys::{CEF_API_VERSION_LAST, cef_resultcode_t};
 use cef::{
-	App, BrowserSettings, CefString, Client, DictionaryValue, ImplCommandLine, RenderHandler, RequestContext, Settings, WindowInfo, api_hash, browser_host_create_browser_sync, execute_process,
+	App, BrowserSettings, CefString, Client, DictionaryValue, ImplCommandLine, ImplRequestContext, RenderHandler, RequestContextSettings, SchemeHandlerFactory, Settings, WindowInfo, api_hash,
+	browser_host_create_browser_sync, execute_process,
 };
 
 use super::CefContext;
 use super::singlethreaded::SingleThreadedCefContext;
 use crate::cef::CefEventHandler;
 use crate::cef::consts::{RESOURCE_DOMAIN, RESOURCE_SCHEME};
-use crate::cef::dirs::{cef_cache_dir, cef_data_dir};
+use crate::cef::dirs::create_instance_dir;
 use crate::cef::input::InputState;
-use crate::cef::internal::{BrowserProcessAppImpl, BrowserProcessClientImpl, RenderHandlerImpl, RenderProcessAppImpl};
+use crate::cef::internal::{BrowserProcessAppImpl, BrowserProcessClientImpl, RenderHandlerImpl, RenderProcessAppImpl, SchemeHandlerFactoryImpl};
 
 pub(crate) struct CefContextBuilder<H: CefEventHandler> {
 	pub(crate) args: Args,
@@ -61,33 +64,37 @@ impl<H: CefEventHandler> CefContextBuilder<H> {
 
 	#[cfg(target_os = "macos")]
 	pub(crate) fn initialize(self, event_handler: H) -> Result<impl CefContext, InitError> {
+		let instance_dir = create_instance_dir();
+
 		let settings = Settings {
 			windowless_rendering_enabled: 1,
 			multi_threaded_message_loop: 0,
 			external_message_pump: 1,
-			root_cache_path: cef_data_dir().to_str().map(CefString::from).unwrap(),
-			cache_path: cef_cache_dir().to_str().map(CefString::from).unwrap(),
+			root_cache_path: instance_dir.to_str().map(CefString::from).unwrap(),
+			cache_path: CefString::from(""),
 			..Default::default()
 		};
 
 		self.initialize_inner(&event_handler, settings)?;
 
-		create_browser(event_handler)
+		create_browser(event_handler, instance_dir)
 	}
 
 	#[cfg(not(target_os = "macos"))]
 	pub(crate) fn initialize(self, event_handler: H) -> Result<impl CefContext, InitError> {
+		let instance_dir = create_instance_dir();
+
 		let settings = Settings {
 			windowless_rendering_enabled: 1,
 			multi_threaded_message_loop: 1,
-			root_cache_path: cef_data_dir().to_str().map(CefString::from).unwrap(),
-			cache_path: cef_cache_dir().to_str().map(CefString::from).unwrap(),
+			root_cache_path: instance_dir.to_str().map(CefString::from).unwrap(),
+			cache_path: CefString::from(""),
 			..Default::default()
 		};
 
 		self.initialize_inner(&event_handler, settings)?;
 
-		super::multithreaded::run_on_ui_thread(move || match create_browser(event_handler) {
+		super::multithreaded::run_on_ui_thread(move || match create_browser(event_handler, instance_dir) {
 			Ok(context) => {
 				super::multithreaded::CONTEXT.with(|b| {
 					*b.borrow_mut() = Some(context);
@@ -103,10 +110,10 @@ impl<H: CefEventHandler> CefContextBuilder<H> {
 	}
 
 	fn initialize_inner(self, event_handler: &H, settings: Settings) -> Result<(), InitError> {
-		let mut cef_app = App::new(BrowserProcessAppImpl::new(event_handler.clone()));
-		let result = cef::initialize(Some(self.args.as_main_args()), Some(&settings), Some(&mut cef_app), std::ptr::null_mut());
 		// Attention! Wrapping this in an extra App is necessary, otherwise the program still compiles but segfaults
+		let mut cef_app = App::new(BrowserProcessAppImpl::new(event_handler.clone()));
 
+		let result = cef::initialize(Some(self.args.as_main_args()), Some(&settings), Some(&mut cef_app), std::ptr::null_mut());
 		if result != 1 {
 			let cef_exit_code = cef::get_exit_code() as u32;
 			if cef_exit_code == cef_resultcode_t::CEF_RESULT_CODE_NORMAL_EXIT_PROCESS_NOTIFIED as u32 {
@@ -118,12 +125,10 @@ impl<H: CefEventHandler> CefContextBuilder<H> {
 	}
 }
 
-fn create_browser<H: CefEventHandler>(event_handler: H) -> Result<SingleThreadedCefContext, InitError> {
+fn create_browser<H: CefEventHandler>(event_handler: H, instance_dir: PathBuf) -> Result<SingleThreadedCefContext, InitError> {
 	let render_handler = RenderHandler::new(RenderHandlerImpl::new(event_handler.clone()));
 	let mut client = Client::new(BrowserProcessClientImpl::new(render_handler, event_handler.clone()));
 
-	let url = CefString::from(format!("{RESOURCE_SCHEME}://{RESOURCE_DOMAIN}/").as_str());
-
 	let window_info = WindowInfo {
 		windowless_rendering_enabled: 1,
 		#[cfg(feature = "accelerated_paint")]
@@ -137,19 +142,37 @@ fn create_browser<H: CefEventHandler>(event_handler: H) -> Result<SingleThreaded
 		..Default::default()
 	};
 
+	let Some(mut incognito_request_context) = cef::request_context_create_context(
+		Some(&RequestContextSettings {
+			persist_session_cookies: 0,
+			cache_path: CefString::from(""),
+			..Default::default()
+		}),
+		Option::<&mut cef::RequestContextHandler>::None,
+	) else {
+		return Err(InitError::RequestContextCreationFailed);
+	};
+
+	let mut scheme_handler_factory = SchemeHandlerFactory::new(SchemeHandlerFactoryImpl::new(event_handler.clone()));
+	incognito_request_context.clear_scheme_handler_factories();
+	incognito_request_context.register_scheme_handler_factory(Some(&CefString::from(RESOURCE_SCHEME)), Some(&CefString::from(RESOURCE_DOMAIN)), Some(&mut scheme_handler_factory));
+
+	let url = CefString::from(format!("{RESOURCE_SCHEME}://{RESOURCE_DOMAIN}/").as_str());
+
 	let browser = browser_host_create_browser_sync(
 		Some(&window_info),
 		Some(&mut client),
 		Some(&url),
 		Some(&settings),
 		Option::<&mut DictionaryValue>::None,
-		Option::<&mut RequestContext>::None,
+		Some(&mut incognito_request_context),
 	);
 
 	if let Some(browser) = browser {
 		Ok(SingleThreadedCefContext {
 			browser,
 			input_state: InputState::default(),
+			instance_dir,
 		})
 	} else {
 		tracing::error!("Failed to create browser");
@@ -171,6 +194,8 @@ pub(crate) enum InitError {
 	InitializationFailed(u32),
 	#[error("Browser creation failed")]
 	BrowserCreationFailed,
+	#[error("Request context creation failed")]
+	RequestContextCreationFailed,
 	#[error("Another instance is already running")]
 	AlreadyRunning,
 }

desktop/src/cef/context/builder.rs

@@ -10,6 +10,7 @@ use super::CefContext;
 pub(super) struct SingleThreadedCefContext {
 	pub(super) browser: Browser,
 	pub(super) input_state: InputState,
+	pub(super) instance_dir: std::path::PathBuf,
 }
 
 impl CefContext for SingleThreadedCefContext {
@@ -33,6 +34,7 @@ impl CefContext for SingleThreadedCefContext {
 impl Drop for SingleThreadedCefContext {
 	fn drop(&mut self) {
 		cef::shutdown();
+		std::fs::remove_dir_all(&self.instance_dir).expect("Failed to remove CEF cache directory");
 	}
 }
 

desktop/src/cef/context/singlethreaded.rs

@@ -4,14 +4,9 @@ use crate::dirs::{ensure_dir_exists, graphite_data_dir};
 
 static CEF_DIR_NAME: &str = "browser";
 
-pub(crate) fn cef_data_dir() -> PathBuf {
-	let path = graphite_data_dir().join(CEF_DIR_NAME);
-	ensure_dir_exists(&path);
-	path
-}
-
-pub(crate) fn cef_cache_dir() -> PathBuf {
-	let path = cef_data_dir().join("cache");
+pub(crate) fn create_instance_dir() -> PathBuf {
+	let instance_id: String = (0..32).map(|_| format!("{:x}", rand::random::<u8>() % 16)).collect();
+	let path = graphite_data_dir().join(CEF_DIR_NAME).join(instance_id);
 	ensure_dir_exists(&path);
 	path
 }

desktop/src/cef/dirs.rs

@@ -17,3 +17,4 @@ pub(super) use browser_process_app::BrowserProcessAppImpl;
 pub(super) use browser_process_client::BrowserProcessClientImpl;
 pub(super) use render_handler::RenderHandlerImpl;
 pub(super) use render_process_app::RenderProcessAppImpl;
+pub(super) use scheme_handler_factory::SchemeHandlerFactoryImpl;

desktop/src/cef/internal.rs

@@ -2,11 +2,9 @@ use std::time::{Duration, Instant};
 
 use cef::rc::{Rc, RcImpl};
 use cef::sys::{_cef_browser_process_handler_t, cef_base_ref_counted_t, cef_browser_process_handler_t};
-use cef::{CefString, ImplBrowserProcessHandler, SchemeHandlerFactory, WrapBrowserProcessHandler};
+use cef::{CefString, ImplBrowserProcessHandler, WrapBrowserProcessHandler};
 
-use super::scheme_handler_factory::SchemeHandlerFactoryImpl;
 use crate::cef::CefEventHandler;
-use crate::cef::consts::RESOURCE_SCHEME;
 
 pub(crate) struct BrowserProcessHandlerImpl<H: CefEventHandler> {
 	object: *mut RcImpl<cef_browser_process_handler_t, Self>,
@@ -22,14 +20,6 @@ impl<H: CefEventHandler> BrowserProcessHandlerImpl<H> {
 }
 
 impl<H: CefEventHandler + Clone> ImplBrowserProcessHandler for BrowserProcessHandlerImpl<H> {
-	fn on_context_initialized(&self) {
-		cef::register_scheme_handler_factory(
-			Some(&CefString::from(RESOURCE_SCHEME)),
-			None,
-			Some(&mut SchemeHandlerFactory::new(SchemeHandlerFactoryImpl::new(self.event_handler.clone()))),
-		);
-	}
-
 	fn on_schedule_message_pump_work(&self, delay_ms: i64) {
 		self.event_handler.schedule_cef_message_loop_work(Instant::now() + Duration::from_millis(delay_ms as u64));
 	}

desktop/src/cef/internal/browser_process_handler.rs

@@ -31,26 +31,14 @@ impl<H: CefEventHandler> SchemeHandlerFactoryImpl<H> {
 }
 
 impl<H: CefEventHandler> ImplSchemeHandlerFactory for SchemeHandlerFactoryImpl<H> {
-	fn create(&self, _browser: Option<&mut Browser>, _frame: Option<&mut Frame>, scheme_name: Option<&CefString>, request: Option<&mut Request>) -> Option<ResourceHandler> {
-		if let Some(scheme_name) = scheme_name {
-			if scheme_name.to_string() != RESOURCE_SCHEME {
-				return None;
-			}
-			if let Some(request) = request {
-				let url = CefString::from(&request.url()).to_string();
-				let path = url.strip_prefix(&format!("{RESOURCE_SCHEME}://")).unwrap();
-				let domain = path.split('/').next().unwrap_or("");
-				let path = path.strip_prefix(domain).unwrap_or("");
-				let path = path.trim_start_matches('/');
-				return match domain {
-					RESOURCE_DOMAIN => {
-						let resource = self.event_handler.load_resource(path.to_string().into());
-						Some(ResourceHandler::new(ResourceHandlerImpl::new(resource)))
-					}
-					_ => None,
-				};
-			}
-			return None;
+	fn create(&self, _browser: Option<&mut Browser>, _frame: Option<&mut Frame>, _scheme_name: Option<&CefString>, request: Option<&mut Request>) -> Option<ResourceHandler> {
+		if let Some(request) = request {
+			let url = CefString::from(&request.url()).to_string();
+			let path = url
+				.strip_prefix(&format!("{RESOURCE_SCHEME}://{RESOURCE_DOMAIN}/"))
+				.expect("CEF should only call this for our custom scheme and domain that we registered this factory for");
+			let resource = self.event_handler.load_resource(path.to_string().into());
+			return Some(ResourceHandler::new(ResourceHandlerImpl::new(resource)));
 		}
 		None
 	}

desktop/src/cef/internal/scheme_handler_factory.rs

@@ -63,6 +63,10 @@ fn main() {
 			tracing::error!("Failed to create CEF browser");
 			exit(1);
 		}
+		Err(cef::InitError::RequestContextCreationFailed) => {
+			tracing::error!("Failed to create CEF request context");
+			exit(1);
+		}
 	};
 
 	tracing::info!("CEF initialized successfully");