[OHOS] Allow setting the log-filter via cli arguments (#36444)

This PR allows setting the log-filter according to the env_filter spec
via CLI arguments.
Testing is currently in progress, will be done on machines running OHOS.

---------

Signed-off-by: Astraea Quinn Skoutelli <astraea.quinn.skoutelli@huawei.com>
Co-authored-by: Jonathan Schwender <schwenderjonathan@gmail.com>

ports/servoshell/egl/ohos.rs

@@ -7,7 +7,7 @@ use std::cell::RefCell;
 use std::mem::MaybeUninit;
 use std::os::raw::c_void;
 use std::sync::mpsc::{Receiver, Sender};
-use std::sync::{Once, OnceLock, mpsc};
+use std::sync::{LazyLock, Once, OnceLock, mpsc};
 use std::thread;
 use std::thread::sleep;
 use std::time::Duration;
@@ -386,32 +386,38 @@ extern "C" fn on_dispatch_key_event(xc: *mut OH_NativeXComponent, _window: *mut
     }
 }
 
+static LOGGER: LazyLock<hilog::Logger> = LazyLock::new(|| {
+    let mut builder = hilog::Builder::new();
+    let filters = [
+        "fonts",
+        "servo",
+        "servoshell",
+        "servoshell::egl:gl_glue",
+        // Show redirected stdout / stderr by default
+        "servoshell::egl::log",
+        // Show JS errors by default.
+        "script::dom::bindings::error",
+        // Show GL errors by default.
+        "canvas::webgl_thread",
+        "compositing::compositor",
+        "compositing::touch",
+        "constellation::constellation",
+        "ohos_ime",
+    ];
+    for &module in &filters {
+        builder.filter_module(module, log::LevelFilter::Debug);
+    }
+
+    builder.filter_level(LevelFilter::Warn).build()
+});
+
 fn initialize_logging_once() {
     static ONCE: Once = Once::new();
     ONCE.call_once(|| {
-        let mut builder = hilog::Builder::new();
-        let filters = [
-            "fonts",
-            "servo",
-            "servoshell",
-            "servoshell::egl:gl_glue",
-            // Show redirected stdout / stderr by default
-            "servoshell::egl::log",
-            // Show JS errors by default.
-            "script::dom::bindings::error",
-            // Show GL errors by default.
-            "canvas::webgl_thread",
-            "compositing::compositor",
-            "compositing::touch",
-            "constellation::constellation",
-            "ohos_ime",
-        ];
-        for &module in &filters {
-            builder.filter_module(module, log::LevelFilter::Debug);
-        }
-
-        builder.filter_level(LevelFilter::Warn).init();
-
+        let logger: &'static hilog::Logger = &LOGGER;
+        let max_level = logger.filter();
+        let r = log::set_logger(logger).and_then(|()| Ok(log::set_max_level(max_level)));
+        debug!("Attempted to register the logger: {r:?} and set max level to: {max_level}");
         info!("Servo Register callback called!");
 
         std::panic::set_hook(Box::new(|info| {
@@ -447,7 +453,26 @@ fn initialize_logging_once() {
         if let Err(e) = super::log::redirect_stdout_and_stderr() {
             error!("Failed to redirect stdout and stderr to hilog due to: {e:?}");
         }
-    })
+    });
+}
+
+pub fn set_log_filter(filter: Option<&str>) {
+    let Some(filter) = filter else {
+        debug!("Called ohos::set_log_filter without providing a filter");
+        return;
+    };
+
+    debug!("Updating log filter to {filter}");
+    let mut builder = env_filter::Builder::new();
+    let filter = match builder.try_parse(filter) {
+        Result::Ok(filter) => filter,
+        Result::Err(err) => {
+            error!("Failed to parse log filter: {err}");
+            return;
+        },
+    };
+    let filter = filter.build();
+    (*LOGGER).set_filter(filter);
 }
 
 fn register_xcomponent_callbacks(env: &Env, xcomponent: &JsObject) -> napi_ohos::Result<()> {

ports/servoshell/egl/ohos/simpleservo.rs

@@ -97,6 +97,8 @@ pub fn init(
     };
 
     crate::init_tracing(servoshell_preferences.tracing_filter.as_deref());
+    #[cfg(target_env = "ohos")]
+    crate::egl::ohos::set_log_filter(servoshell_preferences.log_filter.as_deref());
 
     let Ok(window_size) = (unsafe { super::get_xcomponent_size(xcomponent, native_window) }) else {
         return Err("Failed to get xcomponent size");

ports/servoshell/prefs.rs

@@ -57,6 +57,11 @@ pub(crate) struct ServoShellPreferences {
     /// Where to load userscripts from, if any.
     /// and if the option isn't passed userscripts won't be loaded.
     pub userscripts_directory: Option<PathBuf>,
+
+    /// Log filter given in the `log_filter` spec as a String, if any.
+    /// If a filter is passed, the logger should adjust accordingly.
+    #[cfg(target_env = "ohos")]
+    pub log_filter: Option<String>,
 }
 
 impl Default for ServoShellPreferences {
@@ -75,6 +80,8 @@ impl Default for ServoShellPreferences {
             output_image_path: None,
             exit_after_stable_image: false,
             userscripts_directory: None,
+            #[cfg(target_env = "ohos")]
+            log_filter: None,
         }
     }
 }
@@ -348,6 +355,14 @@ pub(crate) fn parse_command_line_arguments(args: Vec<String>) -> ArgumentParsing
         "FILTER",
     );
 
+    #[cfg(target_env = "ohos")]
+    opts.optmulti(
+        "",
+        "log-filter",
+        "Define a custom filter for logging.",
+        "FILTER",
+    );
+
     opts.optflag(
         "",
         "enable-experimental-web-platform-features",
@@ -408,10 +423,12 @@ pub(crate) fn parse_command_line_arguments(args: Vec<String>) -> ArgumentParsing
     }
     // Env-Filter directives are comma seperated.
     let filters = opt_match.opt_strs("tracing-filter").join(",");
-    let tracing_filter = if filters.is_empty() {
-        None
-    } else {
-        Some(filters)
+    let tracing_filter = (!filters.is_empty()).then_some(filters);
+
+    #[cfg(target_env = "ohos")]
+    let log_filter = {
+        let filters = opt_match.opt_strs("log-filter").join(",");
+        (!filters.is_empty()).then_some(filters)
     };
 
     let mut debug_options = DebugOptions::default();
@@ -626,6 +643,8 @@ pub(crate) fn parse_command_line_arguments(args: Vec<String>) -> ArgumentParsing
         userscripts_directory: opt_match
             .opt_default("userscripts", "resources/user-agent-js")
             .map(PathBuf::from),
+        #[cfg(target_env = "ohos")]
+        log_filter,
         ..Default::default()
     };